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Dang Y.,University of Chinese Academy of Sciences | Qu S.,University of Chinese Academy of Sciences | Wang Z.-X.,University of Chinese Academy of Sciences | Wang X.,University of Colorado at Denver
Journal of the American Chemical Society | Year: 2014

Density functional theory (DFT) calculations (B3LYP and M06) have been utilized to study a newly reported Heck-type reaction that uses an allylic or alkenyl alcohol as substrate and palladium as catalyst in the form of a chelate with a chiral pyridine oxazoline (PyrOx) ligand. The reaction not only controls the regio- and enantioselectivities of arylation of the C=C bond, but also forms the carbonyl functionality up to four bonds away from the aryl substituent via tandem C=C bond migration and enol-to-keto conversion. Computations performed on representative reaction systems allow us to propose a detailed mechanism with several key steps. Initial oxidation of palladium(0) by aryldiazonium generates active arylpalladium(II) species that bind the C=C bond of an allylic or alkenyl alcohol. The activated C=C bond inserts into the palladium-aryl moiety to attain aryl substitution and a chiral carbon center, and the resulting complex undergoes β-hydride elimination to give a new C=C bond that can repeat the insertion/elimination process to move down the carbon chain to form an enol that tautomerizes to a highly stable carbonyl final product. The calculations reveal that the C=C bond migratory insertion step determines both the regioselectivity and the enantioselectivity of arylation, with the former arising mainly from the electronic effect of the hydroxyl group on the charge distribution over the C=C bond and the latter originating from a combination of steric repulsion, trans influence, and C-H/π dispersion interactions. © 2013 American Chemical Society.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Zhan X.,Peking University
Materials Horizons | Year: 2014

Although fullerenes and their derivatives, such as PCBM, have been the dominant electron-acceptor materials in organic photovoltaic cells (OPVs), they suffer from some disadvantages, such as weak absorption in the visible spectral region, limited spectral breadth and difficulty in variably tuning the band gap. It is necessary to explore non-fullerene electron acceptors that will not only retain the favorable electron-accepting and transporting properties of fullerenes but also overcome their insufficiencies. After a decade of mediocrity, non-fullerene acceptors are undergoing rapid development and are emerging as a hot area of focus in the field of organic semiconductors. Solution-processed bulk heterojunction (BHJ) OPVs based on non-fullerene acceptors have shown encouraging power conversion efficiencies of over 4%. This article reviews recent developments in several classes of solution-processable non-fullerene acceptors for BHJ OPVs. The remaining problems and challenges along with the key research directions in the near future are discussed. © The Royal Society of Chemistry 2014.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Wang Y.,CAS Beijing National Laboratory for Molecular | Wang Y.,University of Chinese Academy of Sciences | And 5 more authors.
Advanced Materials | Year: 2014

A novel nonplanar star-shaped perylene diimide acceptor with a triphenylamine core (S(TPA-PDI)) is explored and applied in solution-processed organic solar cells. These solar cells exhibit an encouraging power conversion efficiency of up to 3.32%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Dietzenbacher E.,University of Groningen | Dietzenbacher E.,University of Chinese Academy of Sciences | Pei J.,University of International Business and Economics | Yang C.,CAS Academy of Mathematics and Systems Science
Journal of Environmental Economics and Management | Year: 2012

An input-output framework is adopted to estimate China's carbon dioxide (CO 2) emissions as generated by its exports in 2002. More than one half of China's exports are related to international production fragmentation. These processing exports generate relatively little value added but also relatively little emissions. We argue that existing estimates of the CO 2 content of China's exports are significantly biased because production fragmentation has not been taken into account appropriately. Using a unique tripartite input-output table, we are able to distinguish processing exports from normal exports. Our results show that China's emissions as embodied in its exports are overestimated by more than 60% if the distinction between processing exports and normal exports is not made. Another finding is that each Yuan of value added generated by processing exports leads to 34% less CO 2 emissions than a Yuan of value added generated by normal exports. © 2012 Elsevier Inc..


Peng S.,CAS Chengdu Institute of Mountain Hazards and Environment | Peng S.,University of Chinese Academy of Sciences | Guo T.,Southwest University | Liu G.,CAS Chengdu Institute of Mountain Hazards and Environment
Soil Biology and Biochemistry | Year: 2013

Soil aggregation is a crucial soil property that affects a wide range of physical and chemical processes in soil ecosystems. Arbuscular mycorrhizal (AM) association is recognised as an important promoter of soil aggregation through the action of individual roots, mycelia and an insoluble, glue-like and hydrophobic proteinaceous substance, which is (at least partly) of AM fungi origin, named glomalin-related soil protein. Considering the increasing application of commercial AM inoculants, we addressed how the soil aggregates respond to the hyphal functions of AM inoculation in the field with a resident AM community.To this end, we introduced a new system in which the hyphae were separated by mesh and regular rotation to break the ingrowing hyphae as a control and to demonstrate the causal link between the hyphae and soil aggregates under conditions simulating natural parameters. The results showed the following: (i) the hyphal length was positively correlated with the mean weight diameter (r = 0.384, P < 0.05), geometric mean diameter (r = 0.257, 0.05 < P < 0.10) and easily extractable glomalin (r = 0.296, P < 0.05); (ii) the colonisation rate of the roots in the cores was increased by constantly severing the extraradical mycelium and (iii) the colonisation rate of the control plant roots (approx. 10%) was significantly lower compared to those inoculated with AM fungi (ranging from 34% to 54%). It was concluded that the hyphal networks of AM inoculations can promote the formation and stability of soil aggregates under conditions that closely simulate those occurring in nature. © 2012 Elsevier Ltd.


Li B.,Xinjiang Institute of Ecology and Geography | Li B.,University of Chinese Academy of Sciences | Chen Y.,Xinjiang Institute of Ecology and Geography | Shi X.,Dartmouth College
Journal of Geophysical Research: Atmospheres | Year: 2012

During 1960-2010, the air temperature in the arid region of northwest China had a significant rising trend (P < 0.001), at a rate of 0.343C/decade, higher than the average of China (0.25C/decade) and that of the entire globe (0.13C/decade) for the same period. Based on the analysis of the data from 74 meteorological stations in the region for 1960-2010, we found that among the four seasons the temperature change of winter has been playing the most important role in the yearly change in this region. We also found that the winter temperature in this region has a strong association with the Siberian High (correlation coefficient: R =-0.715) and the greenhouse gas emission (R = 0.51), and between the two the former is stronger. We thus suggest that the weakening of the Siberian High during the 1980s to 1990s on top of the steady increasing of the greenhouse emission is the main reason for the higher rate of the temperature rise in the arid region of the northwest China. © 2012. American Geophysical Union. All Rights Reserved.


Wang H.,Xinjiang Institute of Ecology and Geography | Wang H.,University of Chinese Academy of Sciences | Chen Y.,Xinjiang Institute of Ecology and Geography | Chen Z.,Xinjiang Institute of Ecology and Geography
Hydrological Processes | Year: 2013

On the basis of daily precipitation records at 76 meteorological stations in the arid region, northwest of China, the spatial and temporal distribution of mean precipitation and extremes were analysed during 1960-2010. The Mann-Kendall trend test and linear least square method were utilized to detect monotonic trends and magnitudes in annual and seasonal mean precipitation and extremes. The results obtained indicate that both the mean precipitation and the extremes have increased except in consecutive dry days, which showed the opposite trend. The changes in amplitude of both mean precipitation and extremes show seasonal variability. On an annual basis, the number of rain days (R0.1) has significantly increased. Meanwhile, the precipitation intensity as reflected by simple daily intensity index (SDII), number of heavy precipitation days (R10), very wet days (R95p), max 1-day precipitation amount (RX1day) and max 5-day precipitation amount (RX5day) has also significantly increased. This suggests that the precipitation increase in the arid region is due to the increase in both precipitation frequency and intensity. Trends in extremes are very highly correlated with mean trends of precipitation. The spatial correlation between trends in extremes and trends in the mean is stronger for winter (DJF) than for annual and other seasons. The regional annual and seasonal precipitation and extremes are observed the step jump in mean in the late 1980s. Overall, the results of this study are good indicators of local climate change, which will definitely enhance human mitigation to natural hazards caused by precipitation extremes. © 2012 John Wiley & Sons, Ltd.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Ma L.,University of Chinese Academy of Sciences | Li Y.,CAS Beijing National Laboratory for Molecular | And 4 more authors.
Advanced Energy Materials | Year: 2013

Organic photovoltaic devices and solar cells (OPVs) that can be fabricated by simple solution processing techniques are under intense investigation in academic and industrial laboratories because of their potential to enable mass production of lightweight, fl exible and cost-effective devices. [ 1-4 ] Much of the focus has been on the development of polymer-based OPVs which have seen a dramatic rise in effi ciency over the last decade, and the encouraging power conversion effi ciency (PCE) over 9% has been achieved from bulk heterojunction (BHJ) OPVs based on polymer donors and fullerene acceptors. [ 5 ] Compared with their polymer counterparts, small molecules offer potential advantages in terms of defi ned molecular structure, defi nite molecular weight, easy purifi cation, easy mass-scale production, and good batch-to-batch reproducibility. [ 6-10 ] Recently, great efforts have been dedicated to develop small molecules for application in solar cells, such as linear molecules, [ 11-23 ] star-shaped molecules, [ 24-28 ] and other organic dyes; [ 29 , 30 ] and, so far, the highest PCEs of solution-processed OPVs based on small molecular donors and [6,6]-phenyl-C 61 (or C 71 )-butyric-acid-methyl-ester (PC 61 BM or PC 71 BM) acceptors are over 6% [ 15 , 17 ] and 7%, [ 19 , 20 ] respectively. Despite the fact that considerable progress has been made in small molecule-based OPVs, the relatively low PCE is hindrance to commercialization of these devices.© 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Li Y.,CAS Beijing National Laboratory for Molecular | Zhan X.,CAS Beijing National Laboratory for Molecular | Zhan X.,Peking University
Advanced Energy Materials | Year: 2013

A novel linear non-fullerene acceptor (DBS-2DPP) based on dibenzosilole and diketopyrrolopyrrole is designed and synthesized. DBS-2DPP exhibits strong and broad absorption and appropriate energy levels matching with P3HT. Solution-processed BHJ OSCs based on P3HT:DBS-2DPP show PCEs as high as 2.05%. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yue B.,CAS National Astronomical Observatories | Yue B.,University of Chinese Academy of Sciences | Chen X.,CAS National Astronomical Observatories | Chen X.,Peking University
Astrophysical Journal | Year: 2012

Compared with the cold dark matter (CDM) model, the formation of the small-scale structure of the universe is suppressed in the warm dark matter (WDM) model. It is often thought that this would delay the reionization of the intergalactic medium (IGM) because the star formation rate during the epoch of reionization (EOR) would be lowered. However, during the later stage of the EOR, a large portion of the ionizing photons is consumed by recombination inside the minihalos, which is where the gas has higher density and recombination rates than that in the IGM. The suppression of the small-scale structure would therefore reduce the recombination rate and could potentially shorten the reionization process. This effect is investigated here by using the analytical "bubble model" of reionization. We find that, in some cases, although the initiation of the EOR is delayed in the WDM model, its completion could be even earlier than the CDM case, but the effect is generally small. We obtain limits on the mass of WDM particles for different reionization redshifts. © 2012. The American Astronomical Society. All rights reserved.


Lin Y.,CAS Beijing National Laboratory for Molecular | Ma L.,University of Chinese Academy of Sciences | Li Y.,Peking University | Liu Y.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Advanced Energy Materials | Year: 2014

An oligothiophene-based molecule (BDT-3T-CA) using a molecular engineering approach is applied to solution-processed layer-by-layer solar cells. The solar cells based on BDT-3T-CA/PC61BM (a fullerene derivative) exhibit power conversion efficiency (PCE) values as high as 4.16% and fill factor (FF) values up to 0.75. The FF of 0.75 is the highest value reported for solution processed small molecule solar cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Cheng P.,CAS Beijing National Laboratory for Molecular | Cheng P.,University of Chinese Academy of Sciences | Hou J.,CAS Beijing National Laboratory for Molecular | Li Y.,CAS Beijing National Laboratory for Molecular | Zhan X.,Peking University
Advanced Energy Materials | Year: 2014

Polymer solar cells (PSCs) are fabricated without solvent additives using a low-bandgap polymer, PBDTTT-C-T, as the donor and [6,6]-phenyl-C61-butyric- acid-methyl-ester (PC61BM) as the acceptor. Donor-acceptor blend and layer-by-layer (LL) solution process are used to form active layers. Relative to the blend devices, the LL devices exhibit stronger absorption, better vertical phase separation, higher hole and electron mobilities, and better charge extraction at correct electrodes. As a result, after thermal annealing the LL devices exhibit an average power conversion efficiency (PCE) of 6.86%, which is much higher than that of the blend devices (4.31%). The best PCE of the LL devices is 7.13%, which is the highest reported for LL processed PSCs and among the highest reported for PC61BM-based single-junction PSCs. Polymer solar cells are fabricated without solvent additives using a low-bandgap polymer, PBDTTT-C-T, as the donor and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PC61BM) as the acceptor. After thermal annealing, layer-by-layer solution processed devices exhibit a power conversion efficiency as high as 7.13%, which is much higher than that of blend devices (4.49%), due to efficient vertical phase separation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Qu S.,University of Chinese Academy of Sciences | Dang Y.,University of Chinese Academy of Sciences | Song C.,University of Chinese Academy of Sciences | Wen M.,University of Chinese Academy of Sciences | And 2 more authors.
Journal of the American Chemical Society | Year: 2014

Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and β-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via β-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development. © 2014 American Chemical Society.


Hou Y.,CAS Shanghai Institutes for Biological Sciences | Hou Y.,University of Chinese Academy of Sciences | Zou Q.,Shanghai University | Ge R.,Shanghai University | And 2 more authors.
Cell Research | Year: 2012

Metastatic hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide. However, the cell population responsible for its metastasis remains largely unknown. Here, we reported that CD133 + CD44 +/high defined a subgroup of tumor cells that was responsible for hematogenous metastasis of liver cancers. Immunohistochemical investigation of human HCC specimens revealed that the number of CD133 + and CD44 + HCC cells was increased and was associated with portal vein invasion. Purified CD133 + or CD44 high HCC cells were superior in clonogenic growth and vascular invasion, respectively. Thus, the combination of CD133 and CD44 was used to define a novel HCC sub-population. CD133 + CD44 high, but not CD133 + CD44 low/-, CD133 -CD44 high or CD133 CD44 low/ xenografts, produced intrahepatic or lung metastasis in nude mice. Further analysis of human HCC samples by flow cytometry showed that the number of CD133 + CD44 + tumor cells was associated with portal vein metastasis. The cDNA microarray analysis of CD133 + CD44 + and CD133 + CD44 tumor cells isolated from metastatic HCC patients revealed that these cells comprised of two different populations possessing distinct gene expression profiles. Our results suggest that CD133 + CD44 + tumor cells are a particular population responsible for hematogenous metastasis in liver cancers and that these cells might be targets for treatment of HCC metastasis. © 2012 IBCB, SIBS, CAS All rights reserved.


Li B.,University of Chinese Academy of Sciences | Peng L.,Peking University
IEEE Transactions on Image Processing | Year: 2011

Balanced multiwavelets with interpolatory property are discussed in this paper. This kind of multiwavelets can have a sampling property like Shannon's sampling theorem. It has been shown that the corresponding matrix-valued refinable mask has special structure, and an orthogonal multifilter bank {H(z),G(z)} can be reduced to a scalar valued conjugate quadrature filter (CQF) a(z). But it does not mean that any scalar CQF can form a "good" multifilter bank which can generate a vector-valued refinable function with some degree of smoothness. In the context of balanced multiwavelets, we give the definition of transferring balance order, which a scalar CQF a(z) satisfies, to guarantee that the multiwavelet Ψ generated is balanced. On the basis of the parametrization of a scalar CQF with any length and conditions of transferring balance order, parametrization of multifilter banks which can generate interpolatory multiwavelet and interpolatory scaling function, is gotten. Moreover, some balanced interpolatory multiwavelets have been constructed. Interpolatory analysis-ready multiwavelets (armlets) are also discussed in this paper. It is known that conditions of armlets are easy to validate, compared with balanced multiwavelets. But it will be present that if the corresponding scaling function Φ is interpolatory, the multiwavelet Ψ is balanced of order n if and only if it is an armlet of order n. Finally, the application of balanced multiwavelets with interpolatory property in image processing is also discussed. © 2006 IEEE.


Harn L.,University of Missouri - Kansas City | Lin C.,Fujian Normal University | Lin C.,University of Chinese Academy of Sciences
IEEE Transactions on Computers | Year: 2010

Key transfer protocols rely on a mutually trusted key generation center (KGC) to select session keys and transport session keys to all communication entities secretly. Most often, KGC encrypts session keys under another secret key shared with each entity during registration. In this paper, we propose an authenticated key transfer protocol based on secret sharing scheme that KGC can broadcast group key information to all group members at once and only authorized group members can recover the group key; but unauthorized users cannot recover the group key. The confidentiality of this transformation is information theoretically secure. We also provide authentication for transporting this group key. Goals and security threats of our proposed group key transfer protocol will be analyzed in detail. © 2006 IEEE.


Li B.,University of Chinese Academy of Sciences | Peng L.,Peking University
IEEE Transactions on Image Processing | Year: 2011

The parametrization for one kind of multifilter banks generating balanced multiwavelets is presented in this paper, in which two lowpass filters are flipping filters, and two highpass filters have linear phase. Based on these parametric expressions, some balanced multiwavelets and analysis-ready multiwavelets are constructed, which are symmetric, or antisymmetric. Moreover, on the basis of balanced multiwavelet transform, a new method of multiple description coding is given, and experiments show that this method works well. Compared with the traditional multiple description coding method, this method has low redundancy. © 2011 IEEE.


Zhang C.,CAS Institute of Zoology | Zhang C.,University of Chinese Academy of Sciences | Zhang D.-X.,CAS Institute of Zoology | Zhu T.,Peking University | And 2 more authors.
Systematic Biology | Year: 2011

A Bayesian coalescent-based method has recently been proposed to delimit species using multilocus genetic sequence data. Posterior probabilities of different species delimitation models are calculated using reversible-jump Markov chain Monte Carlo algorithms. The method accounts for species phylogenies and coalescent events in both extant and extinct species and accommodates lineage sorting and uncertainties in the gene trees. Although the method is theoretically appealing, its utility in practical data analysis is yet to be rigorously examined. In particular, the analysis may be sensitive to priors on ancestral population sizes and on species divergence times and to gene flow between species. Here we conduct a computer simulation to evaluate the statistical performance of the method, such as the false negatives (the error of lumping multiple species into one) and false positives (the error of splitting one species into several). We found that the correct species model was inferred with high posterior probability with only one or two loci when 5 or 10 sequences were sampled from each population, or with 50 loci when only one sequence was sampled. We also simulated data allowing migration under a two-species model, a mainland-island model and a stepping-stone model to assess the impact of gene flow (hybridization or introgression). The behavior of the method was diametrically different depending on the migration rate. Low rates at < 0.1 migrants per generation had virtually no effect, so that the method, while assuming no hybridization between species, identified distinct species despite small amounts of gene flow. This behavior appears to be consistent with biologists' practice. In contrast, higher migration rates at ≥ 10 migrants per generation caused the method to infer one species. At intermediate levels of migration, the method is indecisive. Our results suggest that Bayesian analysis under the multispecies coalescent model may provide important insights into population divergences, and may be useful for generating hypotheses of species delimitation, to be assessed with independent information from anatomical, behavioral, and ecological data. © 2011 The Author(s).


Dang Y.,University of Chinese Academy of Sciences | Qu S.,University of Chinese Academy of Sciences | Nelson J.W.,University of Colorado at Denver | Pham H.D.,University of Colorado at Denver | And 2 more authors.
Journal of the American Chemical Society | Year: 2015

Density functional theory (DFT) computations (BP86 and M06-L) have been utilized to elucidate the detailed mechanism of a palladium-catalyzed reaction involving pyridine-type nitrogen-donor ligands that significantly expands the scope of C(sp3)-H activation and arylation. The reaction begins with precatalyst initiation, followed by substrate binding to the Pd(II) center through an amidate auxiliary, which directs the ensuing bicarbonate-assisted C(sp3)-H bond activation producing five-membered-ring cyclopalladate(II) intermediates. These Pd(II) complexes further undergo oxidative addition with iodobenzene to form Pd(IV) complexes, which proceed by reductive C-C elimination/coupling to give final products of arylation. The base-assisted C(sp3)-H bond cleavage is found to be the rate-determining step, which involves hydrogen bond interactions. The mechanism unravels the intimate involvement of the added 2-picoline ligand in every phase of the reaction, explains the isolation of the cyclopalladate intermediates, agrees with the observed kinetic hydrogen isotope effect, and demonstrates the Pd(II)/Pd(IV) redox manifold. © 2015 American Chemical Society.


Li Q.,Beijing University of Technology | Yan Q.-S.,University of Chinese Academy of Sciences | Yan Q.-S.,Peking University | Zhao X.,University of Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

Higgs pair production is crucial for measuring the Higgs boson self-coupling. The dominant channel at hadron colliders is gluon fusion via heavy-quark loops. We present the results of a fully exclusive simulation of gluon fusion Higgs pair production based on the matrix elements for hh+0, 1 partons including full heavy-quark loop dependence, matched to a parton shower. We examine and validate this new description by comparing it with (a) Higgs effective theory predictions, (b) exact hh+0-parton sample showered by Pythia, and (c) exact hh+1-parton distributions, by looking at the most relevant kinematic distributions, such as pTh, pThh, Mhh spectra, and the jet rate as well. We find that matched samples provide a state-of-the-art accurate exclusive description of the final state. © 2014 American Physical Society.


Wang M.,Hefei University of Technology | Gao Y.,National University of Singapore | Lu K.,University of Chinese Academy of Sciences | Rui Y.,Microsoft
IEEE Transactions on Image Processing | Year: 2013

In view-based 3D object retrieval and recognition, each object is described by multiple views. A central problem is how to estimate the distance between two objects. Most conventional methods integrate the distances of view pairs across two objects as an estimation of their distance. In this paper, we propose a discriminative probabilistic object modeling approach. It builds probabilistic models for each object based on the distribution of its views, and the distance between two objects is defined as the upper bound of the Kullback-Leibler divergence of the corresponding probabilistic models. 3D object retrieval and recognition is accomplished based on the distance measures. We first learn models for each object by the adaptation from a set of global models with a maximum likelihood principle. A further adaption step is then performed to enhance the discriminative ability of the models. We conduct experiments on the ETH 3D object dataset, the National Taiwan University 3D model dataset, and the Princeton Shape Benchmark. We compare our approach with different methods, and experimental results demonstrate the superiority of our approach. © 2012 IEEE.


Wang Q.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Wang Q.,Fujian Normal University | Wang Q.,University of Chinese Academy of Sciences
Energy Policy | Year: 2014

As a key issue in China's economic development, urbanisation creates increasing pressure on energy supply and the natural environment. Thus, a better understanding of the relationship between urbanisation and energy consumption is necessary for Chinese decision makers at various levels to address energy security and sustainable economic and social development. This paper empirically investigates the effects of China's urbanisation on residential energy consumption (REC) and production energy consumption (PEC) through a time-series analysis. The results show that compared with rural areas, urbanisation slows per capita REC growth because of the economy of scale and technological advantages associated with urbanisation but has greater promotional effects on the growth of REC and the improvement of REC structure. The economic growth caused by urbanisation most significantly contributes to an increase in PEC, whereas technological advancement was found to reduce the scale of PEC (except from 2001 to 2005). Finally, the structural effect of the energy supply increased rather than decreased China's PEC, and the effect of industrial structure adjustment on PEC was found to be insignificant. © 2013 Elsevier Ltd.


Cheng P.,CAS Beijing National Laboratory for Molecular | Cheng P.,University of Chinese Academy of Sciences | Li Y.,CAS Beijing National Laboratory for Molecular | Zhan X.,Peking University
Energy and Environmental Science | Year: 2014

Indene-C60 bisadduct (ICBA) is used as an electron-cascade acceptor material in poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b] thiophene-4,6-diyl} (PTB7):[6,6]-phenyl-C71-butyric-acid-methyl-ester (PC 71BM) blend to fabricate ternary blend polymer solar cells (PSCs). Due to higher lowest unoccupied molecular orbital (LUMO) energy levels of ICBA relative to PC71BM, the open circuit voltage (VOC) increases with the addition of ICBA. ICBA plays a bridging role between PTB7 and PC71BM, thus providing more routes for charge transfer at the donor/acceptor (D/A) interface. When the ICBA content is much smaller than the PC71BM content, the morphology of the ternary blend active layer is similar to that of the PTB7:PC71BM blend, which guarantees suitable phase separation and efficient charge transport. Ternary blend devices with 15% ICBA content exhibit an average power conversion efficiency (PCE) of 8.13%, higher than that (7.23%) of the PTB7:PC71BM binary blend. Without any further device work (such as interlayer, invert structure and tandem cells), the ternary blend PSCs exhibit PCEs as high as 8.24%, which is the highest reported for ternary blend PSCs and ICBA-related PSCs. This journal is © the Partner Organisations 2014.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Wang J.,Peking University | Zhang Z.-G.,CAS Beijing National Laboratory for Molecular | And 5 more authors.
Advanced Materials | Year: 2015

(Chemical Equation Presented) A novel non-fullerene electron acceptor (ITIC) that overcomes some of the shortcomings of fullerene acceptors, for example, weak absorption in the visible spectral region and limited energy-level variability, is designed and synthesized. Fullerene-free polymer solar cells (PSCs) based on the ITIC acceptor are demonstrated to exhibit power conversion efficiencies of up to 6.8%, a record for fullerene-free PSCs. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.


Cheng P.,CAS Beijing National Laboratory for Molecular | Cheng P.,University of Chinese Academy of Sciences | Ye L.,CAS Beijing National Laboratory for Molecular | Ye L.,University of Chinese Academy of Sciences | And 5 more authors.
Energy and Environmental Science | Year: 2014

Binary additives synergistically boost the power conversion efficiency of all-polymer solar cells up to 3.45%. The nonvolatile additive PDI-2DTT suppresses aggregation of the acceptor PPDIDTT and enhances donor/acceptor mixing, while the additive DIO facilitates aggregation and crystallization of the donor PBDTTT-C-T as well as improves phase separation. Combination of DIO and PDI-2DTT leads to suitable phase separation and improved and balanced charge transport, which is beneficial to efficiency enhancement. This journal is © the Partner Organisations 2014.


Shang L.,CAS Technical Institute of Physics and Chemistry | Bian T.,CAS Technical Institute of Physics and Chemistry | Bian T.,University of Chinese Academy of Sciences | Zhang B.,CAS Technical Institute of Physics and Chemistry | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2014

Graphene nanosheet-supported ultrafine metal nanoparticles encapsulated by thin mesoporous SiO2 layers were prepared and used as robust catalysts with high catalytic activity and excellent high-temperature stability. The catalysts can be recycled and reused in many gas- and solution-phase reactions, and their high catalytic activity can be fully recovered by high-temperature regeneration, should they be deactivated by feedstock poisoning. In addition to the large surface area provided by the graphene support, the enhanced catalytic performance is also attributed to the mesoporous SiO2 layers, which not only stabilize the ultrafine metal nanoparticles, but also prevent the aggregation of the graphene nanosheets. The synthetic strategy can be extended to other metals, such as Pd and Ru, for preparing robust catalysts for various reactions. Layer cake: The synthesis of graphene-nanosheet-supported ultrafine metal nanoparticles encapsulated by thin mesoporous silica layers is reported. The resulting class of robust catalysts was shown to possess high activity, good stability under high temperature conditions, and excellent recyclability and reusability in both gas- and solution-phase reactions. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yang S.,Dalian University | Yang S.,Peking University | Yan Q.-S.,University of Chinese Academy of Sciences
Journal of High Energy Physics | Year: 2012

We study the heavy charged Higgs boson (from 800 GeV to 1500 GeV in this study) in production associated with a top quark at the LHC with the collision energy √s = 14TeV. Such a heavy charged Higgs boson can dominantly decay into a top quark and a bottom quark due to its large Yukawa couplings, like in MSSM. To suppress background events and to confirm the signal, we reconstruct the mass bumps of the heavy charged Higgs boson and the associated top quark. For this purpose, we propose a hybrid-R reconstruction method which utilizes the top tagging technique, a jet substructure technique developed for highly boosted massive particles. By using the full hadronic mode of pp → H ±t → ttb as a test field, we find that this method can greatly reduce the combinatorics in the full reconstruction and can successfully reduce background events down to a controlled level. The sensitivity of LHC to the heavy charged Higgs boson with two b taggings is studied and a 9:5σ significance can be achieved when m H± = 1TeV. © 2012 SISSA.


Zhou X.,Xinjiang Institute of Ecology and Geography | Zhou X.,University of Chinese Academy of Sciences | Zhang Y.,Xinjiang Institute of Ecology and Geography | Downing A.,Macquarie University
Soil Biology and Biochemistry | Year: 2012

Identifying the patterns of soil microbial responses to increasing nitrogen (N) availability are important since microbial processes are related to the potential nutrient transformations. The effects of the addition of N to the soil microbial community of the Gurbantunggut Desert, China, are described in this paper. The study was conducted over a two-year period with trials commencing at the beginning of each growing season. Soil enzyme activity, microbial biomass and microbial community level physiological profile (CLPP) were determined at 0-5cm and 5-10cm soil depths. Nitrogen was added to the soil at five rates plus a control, i.e. 0, 0.5, 1, 3, 6 and 24gNm -2y -1. We hypothesized that soil enzyme activities and microbial biomass N (MBN) would firstly increase and then decrease, and CLPP would be altered with increasing N addition, due to the deleterious effects of higher N addition upon microbial activity. Because of the relatively higher organic matter in the upper depth of soil layers, we further hypothesized that the responses of microbial activities in the 0-5cm depth would be more marked than at 5-10cm. In partial support of our hypothesis, soil enzyme activities, microbial biomass and nutrient concentrations responded to N addition with the most significant changes occurring in the 0-5cm soil depth. Addition of N resulted in an increase in MBN and a decrease in urease activity. Invertase and alkaline phosphatase (AlP) activities increased at low doses of N addition and showed a decrease at higher doses. There was no evidence of change in oxidative enzyme activity at low N treatments but activity decreased at high N additions. However, the CLPP was not affected by N addition. The results of this study suggest that N supplementation in this desert soil may affect C transformation, increase availability of N and P, and immobilize N in the microbial biomass. Responses of the enzyme activity to N supplementation occurred within the context of an apparently stable or unresponsive microbial community structure. © 2011.


Yuan L.,University of Chinese Academy of Sciences | He Y.,University of Chinese Academy of Sciences | He Y.,Peking University
Analyst | Year: 2013

The polymerase chain reaction (PCR) has become an indispensable technique in molecular biology, however, it suffers from low efficiency and specificity problems. Developing suitable additives to effectively avoid nonspecific PCR reactions and explore the mechanism for PCR enhancing is a significant challenge. In this paper, we report three different modified gold nanoparticles (AuNPs) with different surface charge polarities and poly (diallyl dimethylammonium) chloride (PDDA) for use as novel PCR enhancers to improve the efficiency and specificity. These AuNPs included the positively charged PDDA protected AuNPs (PDDA-AuNPs), the neutral PDDA-AuNPs modified with excess chloride ion (PDDA.C-AuNPs), and the negatively charged sodium citrate (Na 3Ct) protected AuNPs (Na3Ct-AuNPs). Our data clearly suggests that the positively charged PDDA-AuNPs with an optimum concentration as low as 1.54 pM could significantly enhance the specificity and efficiency of PCR, however, the optimum concentration of the negatively charged Na 3Ct-AuNPs (2.02 nM) was more than 3 orders of magnitude higher than that of positively charged PDDA-AuNPs. The PCR specificity and efficiency are also improved by the neutral PDDA.C-AuNPs with an optimum concentration, much more than that of the PDDA-AuNPs. This suggests that there should be an electrostatic interaction between the positively charged PDDA-AuNPs and the negatively charged PCR components, and the surface charge polarities of PDDA-AuNPs may play an important role in improving the PCR specificity and efficiency. © 2013 The Royal Society of Chemistry.


Cao Y.,University of Chinese Academy of Sciences | Zhang X.-R.,Peking University
International Journal of Thermal Sciences | Year: 2012

Owing to the environmentally benign nature and the special property variation at supercritical pressure, CO 2 attracts considerable attention in both science and engineering. The CO 2 utilization is regarded as a sustainable way in long term and has become an important global issue. In the present study, a two-dimensional numerical model is used to study the convective flow and heat transfer characteristics of supercritical CO 2 natural circulation in a uniform diameter rectangular loop. Parametric influences of the heat sink temperature, the inclination angle of the loop and the temperature difference on the convection motion and heat transfer performance have been studied. For a given temperature difference, the heat sink temperature has great effect on both flow and heat transfer performance. Increasing the inclination angle decelerates the convective flow and heat transfer processes due to the gradual decrease in buoyancy. With the increase of the temperature difference, both the flow rate and heat transfer performance are found to initially increase, reach a peak, and then decrease gradually. The underlying physics is explored. © 2012 Elsevier Masson SAS. All rights reserved.


Yu Z.,CAS Institute of Biophysics | Yu Z.,University of Chinese Academy of Sciences | Ren M.,Tsinghua University | Wang Z.,Peking University | And 4 more authors.
Genetics | Year: 2013

We report that Cas9/gRNA mediates efficient genetic modifications in Drosophila. Through targeting seven loci, we achieved a germline efficiency of up to 100%. Genes in both heterochromatin and euchromatin can be modified efficiently. Thus the Cas9/gRNA system is an attractive tool for rapid disruption of essentially any gene in Drosophila. © 2013 by the Genetics Society of America.


Lin Y.,CAS Beijing National Laboratory for Molecular | Lin Y.,University of Chinese Academy of Sciences | Zhang Z.-G.,CAS Beijing National Laboratory for Molecular | Bai H.,CAS Beijing National Laboratory for Molecular | And 5 more authors.
Energy and Environmental Science | Year: 2015

A nonfullerene electron acceptor (IEIC) based on indaceno[1,2-b:5,6-b′]dithiophene and 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile was designed and synthesized. IEIC exhibited good thermal stability, strong absorption in the 500-750 nm region with an extinction coefficient of 1.1 × 105 M-1 cm-1 at 672 nm, deep LUMO energy level (-3.82 eV) close to those of fullerenes, and a relatively high electron mobility of 2.1 × 10-4 cm2 V-1 s-1. Fullerene-free polymer solar cells (PSCs) based on the blends of the IEIC acceptor and a low-bandgap polymer donor PTB7-TH, using a perylene diimide derivative as a cathode interlayer, showed power conversion efficiencies (PCEs) of up to 6.31%, which is among the best PCEs reported for fullerene-free PSCs. © 2015 The Royal Society of Chemistry.


Xiu L.,University of Chinese Academy of Sciences | Kunliang G.,China Kweichow Moutai Distillery Co. | Hongxun Z.,University of Chinese Academy of Sciences
World Journal of Microbiology and Biotechnology | Year: 2012

This study endeavored to investigate the diversity of microbes present during the shaping, ripening and drying of Daqu, a fermentation starter culture and substrata complex of Maotai alcoholic spirit. A nested PCR-denaturing gradient gel electrophoresis technique was utilized with different combinations of primers. The results showed the presence of bacteria, yeasts and molds. The microflora, which originate from wheat, were readily detectable during every stage of the fermentation process. However, the microbial structure had clear differences in the shaping, ripening and drying processes. In the shaping stage, there was a high level of diversity of the LAB (lactic acid bacteria) and fungi in the shaped samples. In the ripening stage, however, a reduction of diversity of fungi with a high level of diversity of the Bacilli was observed in the ripened samples. In the drying stage, the diversity of Bacilli and fungi, especially acid-producing bacteria, reduced dramatically. Interestingly, uncultured Lactococcus sp., Microbacterium testaceum, Cochliobolus sp., and Thermoascus crustaceus were the first to be detected in the fermentation starters used in liquor production. This study revealed the microbial diversity and distributions during the shaping, ripening and drying of Daqu-making, facilitating evaluation of the hygienic conditions and aiding in the design of specific starter and/or adjunct cultures. © 2012 Springer Science+Business Media B.V.


Xu L.,CAS Institute of Physics | Xu L.,University of Chinese Academy of Sciences | He J.,CAS Institute of Physics
ACS Applied Materials and Interfaces | Year: 2012

Antifogging and -reflection coatings were fabricated on glass and poly(methyl methacrylate) (PMMA) substrates by integrating solid silica nanoparticles of 25 nm (S-25) and mesoporous silica nanoparticles (MSNs) of 45 nm via layer-by-layer assembly without any post-treatments. Superhydrophilicity and a maximum transmittance of 98.5% in the visible spectral range was achieved for the (PDDA/S-25) 4/(PDDA/MSNs) coating deposited on slide glass. The maximum transmittance even reached as high as 99.3% in the visible spectral range by applying a coating of (PDDA/S-25) 8/(PDDA/MSNs) on PMMA substrate. Scanning and transmission electron microscopy were used to observe the morphology and structure of nanoparticles and coating surfaces. Optical properties were characterized by UV-visible spectrophotometer. Surface wettability was studied by a contact angle/interface system. The influence of mesopores was also discussed on the transmission and wetting properties of coatings. The high porosity of mesoporous nanoparticles and loose stacking of solid and mesoporous nanoparticles are considered to significantly contribute to the enhancements of both light transmission and hydrophilicity. © 2012 American Chemical Society.


He S.,University of Chinese Academy of Sciences | Wang H.,CAS Institute of Atmospheric Physics | Liu J.,CAS Institute of Physics
Journal of Climate | Year: 2013

Interdecadal changes in the relationship between El Niñ o-Southern Oscillation (ENSO) and midlatitude atmospheric circulation are investigated in this study. Comparison of associations between ENSO and midlatitude atmospheric circulation anomalies between 1958-76 and 1977-2010 suggest that during 1958-76, ENSO exerted a strong impact on the East Asian winter monsoon (EAWM) and the associated atmospheric circulation pattern was similar to the positive North Pacific Oscillation (NPO). In contrast, during 1977-2010, the NPO-like atmospheric pattern disappeared. Instead, ENSO exerted a strong impact on the eastern North Pacific Ocean (NP) and North America, and the associated atmospheric circulation pattern resembled the Pacific-North America (PNA) teleconnection. Also, significant correlations between ENSO and sea surface temperature anomalies (SSTAs) over the western subtropical NP during 1958-76 became insignificant during 1977-2010, whereas negative correlations between ENSO and SSTAs in the central and northeastern subtropical NP became more significant since the mid-1970s. Further analyses suggest that the interdecadal shift of the Aleutian low, which occurred around the mid-1970s, might be responsible for the identified changes. Before the mid-1970s, warm ENSO events generated an anomalous anticyclone over the western NP, which is a key system bridging ENSO and EAWM-related atmospheric circulation. After the mid-1970s, the Aleutian low intensified and shifted eastward, leading to the impact of ENSO prevailing over the eastern NP. In addition, the weakened (strengthened) ENSO-NPO/EAWM (ENSO-PNA) relationship likely contributed to the weakened (strengthened) relationship between ENSO and SSTAs over the western (central and eastern) subtropical NP. © 2013 American Meteorological Society.


Song F.,CAS Institute of Atmospheric Physics | Song F.,University of Chinese Academy of Sciences | Zhou T.,CAS Institute of Atmospheric Physics | Zhou T.,Chinese Academy of Sciences | Qian Y.,Pacific Northwest National Laboratory
Geophysical Research Letters | Year: 2014

In this study, we examined the responses of East Asian summer monsoon (EASM) to natural (solar variability and volcanic aerosols) and anthropogenic (greenhouse gasses and aerosols) forcings simulated in the 17 latest Coupled Model Intercomparison Program phase 5 models with 105 realizations. The observed weakening trend of low-level EASM circulation during 1958-2001 is partly reproduced under all-forcing runs. A comparison of separate forcing experiments reveals that the aerosol forcing plays a primary role in driving the weakened low-level monsoon circulation. The preferential cooling over continental East Asia caused by aerosol affects the monsoon circulation through reducing the land-sea thermal contrast and results in higher sea level pressure over northern China. In the upper level, both natural forcing and aerosol forcing contribute to the observed southward shift of East Asian subtropical jet through changing the meridional temperature gradient. ©2013. American Geophysical Union. All Rights Reserved.


Lin R.,University of Chinese Academy of Sciences | Zhou T.,University of Chinese Academy of Sciences | Qian Y.,Pacific Northwest National Laboratory
Journal of Climate | Year: 2014

With the motivation to identify whether a reasonably simulated atmospheric circulation would necessarily lead to a successful reproduction of monsoon precipitation, the performances of five sets of reanalysis data [NCEP-U.S. Department of Energy (DOE) Atmospheric Model Intercomparison Project II (AMIP-II) reanalysis (NCEP-2), 40-yr ECMWF Re-Analysis (ERA-40), Japanese 25-yr Reanalysis Project (JRA-25), Interim ECMWF Re-Analysis (ERA-Interim), and Modern-Era Retrospective Analysis for Research and Applications(MERRA)] in reproducing the climatology, interannual variation, and long-term trend of global monsoon (GM) precipitation are comprehensively evaluated. To better understand the variability and longterm trend of GM precipitation, the authors also examined the major components of water budget, including evaporation, water vapor convergence, and the change in local column water vapor, based on the five reanalysis datasets. Results show that all five reanalysis datasets reasonably reproduce the climatology of GM precipitation. ERA-Interim (NCEP-2) shows the highest (lowest) skill among the five datasets. The observed GMprecipitation shows an increasing tendency during 1979-2011 along with a strong interannual variability, which is reasonably reproduced by five reanalysis datasets. The observed increasing trend ofGMprecipitation is dominated by contributions from the Asian, North American, Southern African, and Australian monsoons. All five datasets fail in reproducing the increasing tendency of the North African monsoon precipitation. The wind convergence term in the water budget equation dominates the GM precipitation variation, indicating a consistency between the GM precipitation and the seasonal change of prevailing wind. © 2014 American Meteorological Society.


Liu H.,CAS Hefei Key Laboratory of Materials for Energy Conversion | Liu H.,University of Chinese Academy of Sciences | Shi X.,CAS Hefei Key Laboratory of Materials for Energy Conversion | Shi X.,CAS Shanghai Institute of Ceramics | And 8 more authors.
Nature Materials | Year: 2012

Advanced thermoelectric technology offers a potential for converting waste industrial heat into useful electricity, and an emission-free method for solid state cooling. Worldwide efforts to find materials with thermoelectric figure of merit, zT values significantly above unity, are frequently focused on crystalline semiconductors with low thermal conductivity. Here we report on Cu 2-x Se, which reaches a zT of 1.5 at 1,000 K, among the highest values for any bulk materials. Whereas the Se atoms in Cu 2 -x Se form a rigid face-centred cubic lattice, providing a crystalline pathway for semiconducting electrons (or more precisely holes), the copper ions are highly disordered around the Se sublattice and are superionic with liquid-like mobility. This extraordinary liquid-like behaviour of copper ions around a crystalline sublattice of Se in Cu 2-x Se results in an intrinsically very low lattice thermal conductivity which enables high zT in this otherwise simple semiconductor. This unusual combination of properties leads to an ideal thermoelectric material. The results indicate a new strategy and direction for high-efficiency thermoelectric materials by exploring systems where there exists a crystalline sublattice for electronic conduction surrounded by liquid-like ions. © 2012 Macmillan Publishers Limited. All rights reserved.


Song B.,CAS Shanghai Institute of Ceramics | Song B.,University of Chinese Academy of Sciences | Wu C.,CAS Shanghai Institute of Ceramics | Chang J.,CAS Shanghai Institute of Ceramics | Chang J.,Shanghai JiaoTong University
Acta Biomaterialia | Year: 2012

The aim of this study was to fabricate dual drug-loaded poly(lactic-co-glycolic acid) (PLGA)/mesoporous silica nanoparticles (MSNs) electrospun composite mat, with the two model drugs (fluorescein (FLU) and rhodamine B (RHB)) releasing in separate and distinct release kinetics. The PLGA-based electrospun mat loading with the same amount of FLU (5%, with respect to the weight of PLGA) and different amounts of RHB-loaded MSNs (5, 15 and 25%, with respect to the weight of PLGA) were prepared and studied for their releasing properties. The morphology of the composite mats was characterized by scanning electron microscopy and transmission electron microscopy. Finally, the release profiles of the dual drug-loaded electrospun mats were measured, and the results indicated that the FLU and RHB released from the PLGA/FLU/RHB-loaded MSNs electrospun mats showed separate and distinct profiles. Most of the FLU was released rapidly during the 324 h of the trial; however, RHB showed a sustained release behavior, and the release rate could be controlled by the content of the RHB-loaded MSNs in the electrospun mat. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Zhu R.,Shanghai JiaoTong University | Zhu R.,CAS Institute of High Energy Physics | Qiao C.-F.,University of Chinese Academy of Sciences | Qiao C.-F.,CAS Institute of High Energy Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2016

The diquark-triquark model is used to explain charmonium-pentaquark states, i.e., Pc(4380) and Pc(4450), which were observed recently by the LHCb Collaboration. For the first time, we investigate the properties of the color attractive configuration of a triquark and we define a nonlocal light cone distribution amplitude for pentaquark states, where both diquark and triquark are not pointlike, but they have nonzero size. We establish an effective diquark-triquark Hamiltonian based on spin-orbital interaction. According to the Hamiltonian, we show that the minimum mass splitting between 5/2+ and 3/2- is around 100 MeV, which may naturally solve the challenging problem of small mass splitting between Pc(4450) and Pc(4380). This helps to understand the peculiarities of Pc(4380) with a broad decay width whereas Pc(4450) has a narrow decay width. Based on the diquark-triquark model, we predict more pentaquark states, which will hopefully be measured in future experiments. © 2016 The Authors.


Wu L.,University of Chinese Academy of Sciences | Yang H.-Q.,University of Chinese Academy of Sciences | Yang H.-Q.,Shanghai JiaoTong University
Molecular Plant | Year: 2010

Plants have evolved complex mechanisms to defend themselves against pathogens. It has been shown that several defense responses are influenced by light, and the red/far-red light photoreceptor phytochromes (PHY) modulate plant defense responses in Arabidopsis. Blue light receptor cryptochromes (CRY) work together with PHY to regulate many light-controlled responses, including photomorphogenesis, floral induction, and entrainment of the circadian clock. We report here that the Arabidopsis blue light photoreceptor CRY1 positively regulates inducible resistance to Pseudomonas syringae under continuous light conditions. By challenging plants with P. syringae pv. tomato (Pst.) DC3000 carrying avrRpt2, we demonstrate that effector-triggered local resistance is down-regulated in the cry1 mutant, leading to more pathogen multiplication. In plants overexpressing CRY1 (CRY1-ovx), however, local resistance is significantly up-regulated. We also show that systemic acquired resistance (SAR) is positively regulated by CRY1, and that salicylic acid (SA)-induced pathogenesis-related gene PR-1 expression is reduced in the cry1 mutant, but enhanced in CRY1-ovx plants. However, our results indicate that CRY1 only modestly influences SA accumulation and has no effect on hypersensitive cell death. These results suggest that CRY1 may positively regulate R protein-mediated resistance to P. syringae with increased PR gene expression. © The Author 2010. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPP and IPPE, SIBS, CAS.


Yuan G.,Beijing University of Posts and Telecommunications | Zhang X.,Beijing University of Posts and Telecommunications | Wang W.,Beijing University of Posts and Telecommunications | Yang Y.,University of Chinese Academy of Sciences
IEEE Communications Magazine | Year: 2010

In order to achieve up to 1 Gb/s peak data rate in future IMT-Advanced mobile systems, carrier aggregation technology is introduced by the 3GPP to support very-high-data-rate transmissions over wide frequency bandwidths (e.g., up to 100 MHz) in its new LTE-Advanced standards. This article first gives a brief review of continuous and non-continuous CA techniques, followed by two data aggregation schemes in physical and medium access control layers. Some technical challenges for implementing CA technique in LTE-Advanced systems, with the requirements of backward compatibility to LTE systems, are highlighted and discussed. Possible technical solutions for the asymmetric CA problem, control signaling design, handover control, and guard band setting are reviewed. Simulation results show Doppler frequency shift has only limited impact on data transmission performance over wide frequency bands in a high-speed mobile environment when the component carriers are time synchronized. The frequency aliasing will generate much more interference between adjacent component carriers and therefore greatly degrades the bit error rate performance of downlink data transmissions. © 2010 IEEE.


Liao B.,Shanghai JiaoTong University | Liao B.,University of Chinese Academy of Sciences | Jin Y.,Shanghai JiaoTong University
Cell Research | Year: 2010

Transcription factor Oct4 plays critical roles in maintaining pluripotency and controlling lineage commitment of embryonic stem cells (ESCs). Our previous study indicates that Wwp2, a mouse HECT-type E3 ubiquitin ligase, ubiquitinates Oct4 and promotes its degradation in a heterologous system. However, roles of Wwp2 in regulating endogenous Oct4 protein levels as well as molecular characteristics of the function of Wwp2 have not been determined. Here, we report that Wwp2 plays an important role in Oct4 ubiquitination and degradation during differentiation of embryonal carcinoma cells (ECCs), although it does not appear to affect Oct4 protein levels in the undifferentiated ECCs and ESCs. Importantly, inhibition of Wwp2 expression by specific RNA interference elevates the Oct4 protein level, leading to attenuation in retinoid acid-induced activation of differentiation-related marker genes. Mechanistically, Wwp2 catalyzes Oct4 poly-ubiquitination via the lysine 63 linkage in a dosage-dependent manner. Interestingly, Wwp2 also regulates its own ligase activity in a similar manner. Moreover, auto-ubiquitination of Wwp2 occurs through an intra-molecular mechanism. Taken together, these results demonstrate a crucial role of Wwp2 in controlling endogenous Oct4 protein levels during differentiation processes of ECCs and suggest an interesting dosage-dependent mechanism for regulating the catalytic activity of the E3 ubiquitin ligase, Wwp2. © 2010 IBCB, SIBS, CAS All rights reserved.


Zhang J.,University of Chinese Academy of Sciences | Liu J.,Jiangxi Academy of Agricultural science | Liu R.,University of Chinese Academy of Sciences
Bioresource Technology | Year: 2015

In this study, the effects of pyrolysis temperature and heating time on the yield and physicochemical and morphological properties of biochar obtained from straw and lignosulfonate were investigated. As pyrolysis temperature increased, pH, ash content, carbon stability, and total content of carbon increased while biochar yield, volatile matter, total content of hydrogen, oxygen, nitrogen and sulfur decreased. The data from scanning electron microscope image and nuclear magnetic resonance spectra indicated an increase in porosity and aromaticity of biochar produced at a high temperature. The results showed that feedstock types could also influence characteristics of the biochar with absence of significant effect on properties of biochar for heating time. © 2014 Elsevier Ltd.


Chen H.,University of Chinese Academy of Sciences | Chen H.,Nanjing University of Information Science and Technology | Sun J.,University of Chinese Academy of Sciences
Journal of Climate | Year: 2015

The standardized precipitation evapotranspiration index (SPEI) is computed and compared in China using reference evapotranspiration calculated using the Thornthwaite (TH) approach and the Penman-Monteith (PM) equation. The analysis reveals that SPEI_PM outperforms the SPEI_TH with regard to drought monitoring during the period 1961-2012 over China, especially in arid regions of China. Furthermore, the SPEI_PM also performs better with regard to observed variations in soil moisture and streamflow in China. Thus, changes in drought characteristics over China are detected on the basis of variations in the SPEI_PM. The results indicate that droughts over China exhibit pronounced decadal variations over the past 50 yr, with more frequent and severe droughts occurring before the 1980s and in the 2000s compared with the 1980s and 1990s. Since the late 1990s, droughts have become more frequent and severe across China, especially in some regions of northern China. Concurrently, consecutive drought events have also increased across China. This suggests that dry conditions in China have been enhanced in recent years. Further analyses illustrate that the temperature and precipitation anomalies exhibit different roles in detecting droughts across China, which is primarily due to the magnitude of their variations and different climate variability. Considering temperature and precipitation perturbations, droughts exhibit relatively larger responses to temperature fluctuations in northern China and relatively larger responses to precipitation anomalies in southern China. © 2015 American Meteorological Society.


Zhu L.,Shanghai JiaoTong University | Zhang S.,Shanghai JiaoTong University | Zhang S.,University of Chinese Academy of Sciences | Jin Y.,Shanghai JiaoTong University
EMBO Reports | Year: 2014

Pluripotency-associated transcription factor Foxd3 is required for maintaining pluripotent cells. However, molecular mechanisms underlying its function are largely unknown. Here, we report that Foxd3 suppresses differentiation induced by calcineurin-NFAT signaling to maintain the ESC identity. Mechanistically, Foxd3 interacts with NFAT proteins and recruits co-repressor Tle4, a member of the Tle repressor family highly expressed in undifferentiated ESCs, to suppress NFATc3's transcriptional activities. Furthermore, global transcriptome analysis shows that Foxd3 and NFATc3 co-regulate a set of differentiation-associated genes in ESCs. Collectively, our study establishes a molecular and functional link between a pluripotency-associated factor and an important ESC differentiation-inducing pathway. © 2014 The Authors.


News Article | November 30, 2016
Site: www.eurekalert.org

In the 12 years since David Gross won his Nobel Prize, the UC Santa Barbara theoretical physicist has been celebrated myriad times. His latest accolades come from China and Russia. This year, the University of Chinese Academy of Sciences awarded Gross an honorary doctorate degree, an event so rare in that country that it requires government approval. And more recently, the Russian Academy of Sciences confirmed Gross as a foreign member and awarded him the Medal of Honor in recognition of his "outstanding and fundamental contributions to quantum chromodynamics." Gross shared the Nobel Prize in physics with David Politzer and Frank Wilczek for their work in that field. Quantum chromodynamics is the theory of the nuclear force that holds quarks together and binds them inside protons and neutrons. "It is wonderful to see David recognized for his groundbreaking work and his continued impact on theoretical physics around the world," said Lars Bildsten, director of UCSB's Kavli Institute for Theoretical Physics (KITP). "David is a strong advocate for the value of physics as a pillar in fundamental research, and I look forward to his future term as president of the American Physical Society." (Gross just began a four-year term at the APS, where he is currently vice president.) Gross has longtime scientific ties to both China and Russia. Since winning the Nobel in 2004, he has worked with Chinese physicists to improve the country's Institute of Theoretical Physics and has been an adviser to a project that will build a supercollider at least twice the size of the Large Hadron Collider in Switzerland. When the Soviet Union still existed, Gross was a frequent visitor. Last year, he was invited to the Joint Institute for Nuclear Research in Dubna, outside of Moscow, to mark the building of a new heavy-ion accelerator that will be able to create quark matter. "I did my original work formulating the theory of these quarks and quantum chromodynamics, which is well-tested in many regimes," said Gross, who is a permanent member of the KITP and its Chancellor's Chair Professor of Theoretical Physics. "Dubna is going to create an intense heavy-ion beam -- with less energy and lower temperature than the Large Hadron Collider but denser -- so they can probe a different regime of the physics of this quark matter, one that potentially could be very interesting." Gross received his bachelor's and master's degrees from Hebrew University in Jerusalem in 1962 and his doctorate from UC Berkeley in 1966. A junior fellow at Harvard University before moving to Princeton University, he joined UCSB in 1997 as director of the KITP, where he served until 2012. In addition to the Nobel Prize, Gross' many honors and awards include the J.J. Sakurai Prize for Theoretical Particle Physics from the American Physical Society; a MacArthur Fellowship; the Dirac Medal from the International Centre for Theoretical Physics; the Oskar Klein Medal of the Royal Swedish Academy of Sciences; the High Energy and Particle Physics Prize from the European Physical Society; and the Grande Médaille D'or de l'Académie des Science, France. Gross has delivered lectures around the world and holds numerous honorary doctorates and professorships. He has written hundreds of articles as well as conference proceedings and book chapters.


News Article | November 22, 2016
Site: www.eurekalert.org

WASHINGTON -- In today's digital world it can be challenging to prevent photos, videos and books from being illegally copied and distributed. A new light-based technique is making it more practical to create secure, invisible watermarks that can be used to detect and prosecute counterfeiting. "In our research, we use a complex pattern of light, or diffraction pattern, as a unique watermark," said Yishi Shi, from the University of Chinese Academy of Sciences, China. "The invisible watermark is embedded into the content we are trying to protect. Imperceptibility is one of the most significant advantages of optical watermarking." In The Optical Society's journal Optics Express, Shi and colleagues report a new approach that encodes the optical watermark in a single step. The new technique is faster and uses a less complex optical setup than other optical watermarking approaches previously pursued. The new technique can also be used to optically encrypt data or to hide information within images. The new method is based on a technique called single-shot ptychography encoding (SPE) that uses multiple partially-overlapping beams of light to generate a diffraction pattern from a complex object. Unlike other methods, SPE can encode the optical watermark in a single exposure with no mechanical scanning. SPE is also less prone to error than other methods and uses a simpler optical setup. In addition to conducting numerical simulations to test their method, the researchers carried out an optical experiment showing the usefulness of SPE. "Most methods for optical watermarking have only been demonstrated with simulations," said Shi. "Our experiment shows that our method is suitable for practical optical watermarking." For the optical experiment, the researchers used SPE to create a complex watermark consisting of a diffraction pattern of multiple tiny spots. Prior to embedding the watermark into a host image, they used computer processing to remove any repeated data and to scramble the diffraction pattern, making it easier to embed the watermark and further improving its security. The spot size can be reduced to smaller than 10 microns, which helps prevent degradation of the host image. Once a watermark is embedded into digital media, there are multiple ways to detect it to check for authenticity. If someone knows an optical watermark is present, it can be detected by subtracting the host image from the watermarked image and then using a special security key and extraction algorithm. For cases where the presence of a watermark is unknown, the watermark could be extracted using existing algorithm-based detection methods. The researchers are now working to apply SPE to dynamic watermarking, which creates watermarks from objects that change quickly. For example, the variations that occur within a biological cell could be recorded and used to create a special watermark. They also plan to use SPE for multi-image watermarking and even 3D watermarking, while also working to further enhance the imaging quality of single-shot ptychography. "The successful implementation of SPE will be a big breakthrough for optical security and could bring SPE-based optical watermarking and encryption closer to commercial application," said Shi. Optics Express reports on new developments in all fields of optical science and technology every two weeks. The journal provides rapid publication of original, peer-reviewed papers. It is published by The Optical Society and edited by Andrew M. Weiner of Purdue University. Optics Express is an open-access journal and is available at no cost to readers online at: OSA Publishing. Founded in 1916, The Optical Society (OSA) is the leading professional organization for scientists, engineers, students and entrepreneurs who fuel discoveries, shape real-life applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership initiatives, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of optics and photonics experts. For more information, visit osa.org/100.


Wang J.,University of Chinese Academy of Sciences | Li Y.,Beihang University | Zhang Y.,Beihang University
Advanced Functional Materials | Year: 2014

Hydrous hydrazine (H2NNH2·H2O) has generally been considered a promising hydrogen storage carrier because of inherent advantages such as its high hydrogen content and easy recharging as a liquid. Unfortunately, the decomposition of hydrous hydrazine to H2 is terribly sluggish and/or not entirely favored - a competing decomposition to ammonia may be preferred. This has been the case using noble-metal catalysts and using non-precious-metal-based catalysts, even at elevated temperatures. To overcome this challenge, non-precious-metal-based Cu@Fe5Ni5 core@shell nanocatalysts are prepared using an in situ seeding-growth approach. Unexpectedly, the catalyst exerts 100% H 2 selectivity and excellent activity and stability toward the complete decomposition of hydrous hydrazine, which is due to the synergistic effect of the core@shell structure. These promising results will certainly promote the effective application of hydrous hydrazine as a potential hydrogen storage material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA.


Han W.-Y.,CAS Chengdu Institute of Organic Chemistry | Han W.-Y.,CAS Chengdu Institute of Biology | Wu Z.-J.,University of Chinese Academy of Sciences | Zhang X.-M.,CAS Chengdu Institute of Organic Chemistry | Yuan W.-C.,CAS Chengdu Institute of Organic Chemistry
Organic Letters | Year: 2012

The catalytic enantioselective three-component Petasis reaction among salicylaldehydes, amines, and organoboronic acids with a newly designed thiourea-binol catalyst is presented. A broad range of alkylaminophenols can be obtained in good yield (up to 92%) and good to high enantioselectivity (up to 95% ee). A possible reaction pathway for this catalytic enantioselective Petasis reaction is tentatively proposed. © 2012 American Chemical Society.


Zhou L.,Hunan Normal University | Yang L.-P.,University of Chinese Academy of Sciences | Li Y.,Beijing Computational Science Research Center | Sun C.P.,Beijing Computational Science Research Center
Physical Review Letters | Year: 2013

We propose an experimentally accessible single-photon routing scheme using a â-type three-level atom embedded in quantum multichannels composed of coupled-resonator waveguides. Via the on-demand classical field being applied to the atom, the router can extract a single photon from the incident channel, and then redirect it into another. The efficient function of the perfect reflection of the single-photon signal in the incident channel is rooted in the coherent resonance and the existence of photonic bound states. © 2013 American Physical Society.


Cun Y.-Z.,CAS Institute of Botany | Cun Y.-Z.,University of Chinese Academy of Sciences | Wang X.-Q.,CAS Institute of Botany
Molecular Phylogenetics and Evolution | Year: 2010

The Himalaya-Hengduan Mountains region (HHM) in the southern and southeastern Qinghai-Tibetan Plateau (QTP) is considered an important reservoir and a differentiation center for temperate and alpine plants in the Cenozoic. To reveal how plants responded to the Quaternary climatic oscillations in the QTP, the phylogeographical histories of a few subalpine and alpine plants have been investigated, but nearly all studies used only uniparentally inherited cytoplasmic DNA markers, and only a couple of them included sampling from the Himalaya. In this study, range-wide genetic variation of the Himalayan hemlock (Tsuga dumosa), an important forest species in the HHM, was surveyed using DNA markers from three genomes. All markers revealed genetic depauperation in the Himalaya and richness in the Hengduan Mountains populations. Surprisingly, population differentiation of this wind-pollinated conifer is very high in all three genomes, with few common and many private nuclear gene alleles. These results, together with fossil evidence, clearly indicate that T. dumosa recolonized the Himalaya from the Hengduan Mountains before the Last Glacial Maximum (LGM), accompanied with strong founder effects, and the influence of the earlier glaciations on demographic histories of the QTP plants could be much stronger than that of the LGM. The strong population differentiation in T. dumosa could be attributed to restricted gene flow caused by the complicated topography in the HHM that formed during the uplift of the QTP, and thus sheds lights on the importance of geographical isolation in the development of high plant species diversity in this biodiversity hotspot. © 2010 Elsevier Inc.


Chen K.,Beihang University | Chen K.,CAS Institute of Policy and Management | Guan J.,University of Chinese Academy of Sciences
Technovation | Year: 2011

The research about the innovation production process (IPP) is burgeoning. Our understanding of the interdependent interactions between functionally distinct innovation activities during it from a systemic perspective is rather unclear, yet, which is beneficial to empirical innovation management. This study, based on systems thinking, presents a novel analytical framework to empirically and quantitatively map the IPP jointly associated with a path modeling approach, which helps in untangling the interactive mechanism between stage-specific innovation activities with distinct functions within an IPP from accumulative advantage to economic outcomes. We use the attractive analytical framework to guide an empirical investigation to the Chinas high-tech industries IPP at the macro-regional level. Our empirical study confirms the dominant role of previous innovation capital accumulation in the whole IPP embedded into regional innovation systems of Chinas high-tech industries. That is, we prove the existence of accumulative advantage phenomenon in the regional IPP. The examination results show that there is a significant Matthew effect of technological innovation accumulation on technological innovation inputs as well as the Path dependence of technological innovation outputs/outcomes on technological innovation accumulation. This indicates that the innovation-practitioners should promote innovation capital accumulation for sustainable innovations and economic profits in a long time. At the same time, our findings suggest that, in order to alleviate the cross-regional unbalance of innovation development and promote radial innovations in Chinas high-tech industries, both policy-makers and innovation-practitioners should try to get rid of the dependence on the previous accumulated innovation capital. © 2011 Elsevier Ltd.


Chu Z.,CAS Chengdu Institute of Organic Chemistry | Chu Z.,University of Chinese Academy of Sciences | Feng Y.,CAS Chengdu Institute of Organic Chemistry
Chemical Communications | Year: 2010

A novel pH-switchable wormlike micellar system was prepared by mixing N-erucamidopropyl-N,N-dimethylamine and maleic acid with molar ratio of 2:1. The viscosity of the micellar solution is switchable via tuning the pH through the addition of minor acid or base. Such a system possesses the characteristics of a facile, rapid, cost-effective reversible process and recyclable cheaper materials. © 2010 The Royal Society of Chemistry.


Liu M.,CAS National Center for Nanoscience and Technology | Liu M.,University of Chinese Academy of Sciences | Jiang L.,CAS Institute of Chemistry | Jiang L.,Beihang University
Advanced Functional Materials | Year: 2010

Construction and application of surfaces with switchable liquidsolid adhesion have generated worldwide interest during the past a few years. These surfaces are of great importance not only for fundamental research but for various practical applications in smart and fluid-controllable devices. This Feature Article reviews several techniques that have been developed to switch the adhesion on liquid/solid interfaces, including tuning the surface chemical composition, tailoring the surface morphology, and applying external stimuli. Particular attention is paid to superhydrophobic surfaces with reversible switching between low- and high-adhesion to water droplets in response to external stimuli. The dynamic behavior of water droplets on such surfaces can be controlled ranging from rolling to pinning state, while maintaining superhydrophobic states. In addition, smart adhesion in oil/water/solid system and platelet/water/solid system are also discussed, which is of importants for application in designing novel anti-bioadhesion materials. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chu Z.,CAS Chengdu Institute of Organic Chemistry | Chu Z.,University of Chinese Academy of Sciences | Feng Y.,CAS Chengdu Institute of Organic Chemistry
Langmuir | Year: 2012

Long-chain amidosulfobetaine surfactants, 3-(N-fattyamidopropyl-N,N- dimethyl ammonium) propanesulfonates (n-DAS, n > 18), are insoluble in pure water due to their high Krafft temperature (T K), while they are soluble when inorganic salt is added to the surfactant solution as the T K of these zwitterionic surfactants is decreased. The influence of the salt content and ionic species of the added electrolytes on the T K of the series of amidosulfobetaine surfactants was examined by means of UV-vis spectrophometry and visual inspection. It was found that the T K of these surfactants depends strongly on not only the hydrophobic alkyl length (n), but also the salinity of the aqueous environment. When the salt concentration is increased from 0 to 100 mM, the T K shows a sharp decrease; when the salinity is fixed between 100 and 2000 mM, the T K varies linearly with n with a slope of ∼7.7 irrespective of the salt species and the salt content. When the salt concentration is further increased above 2000 mM, a linear function is still observed, but the slope increases slightly. © 2011 American Chemical Society.


He L.-J.,CAS Institute of Botany | He L.-J.,University of Chinese Academy of Sciences | Zhang X.-C.,CAS Institute of Botany
Molecular Phylogenetics and Evolution | Year: 2012

Thelypteridaceae is one of the largest families of polypodioid ferns. The generic classification of the family is still controversial because of high levels of convergent or parallel evolution of morphological characters and a lack of molecular phylogenetic studies. In the present study, phylogenetic analyses of three chloroplast regions (rbcL, rps4 and trnL. -trnF intergenic spacer region) for 115 taxa, representing 27 recognized segregates in the family, were conducted to explore infrafamilial relationships and gain further understanding of generic boundaries. The phylogenetic reconstructions resolved six distinct clades (Clade I-VI) with strong support. Seven genera: Cyclogramma, Macrothelypteris, Oreopteris, Phegopteris, Pseudophegopteris, Stegnogramma, and Thelypteris are recognized from Clades I, II, IV, and V. In Clade III, Metathelypteris was supported as monophyletic, but the other segregates Amauropelta, Coryphopteris, and Parathelypteris were polyphyletic or paraphyletic, preventing clear recognition of generic boundaries within this clade without additional sampling. Considering great morphological homoplasy within Clade VI, a large genus Cyclosorus is recognized to comprise several small recognized segregates. Within this clade, Pronephrium, and Christella were revealed to be polyphyletic, but several Asian-endemic segregates, such as Glaphyropteridopsis, Mesopteris, and Pseudocyclosorus were strongly supported as monophyletic. Analyses of the evolution of morphological character states on the molecular phylogeny showed extremely high levels of homoplastic evolution for many diagnostic characters. © 2012 Elsevier Inc.


Wu Z.-Q.,CAS Institute of Botany | Ge S.,University of Chinese Academy of Sciences
Molecular Phylogenetics and Evolution | Year: 2012

Despite the considerable efforts to reconstruct the phylogeny of grasses, the relationships among the subfamilies Bambusoideae, Pooideae and Ehrhartoideae in the BEP clade remain unresolved. Here we completely sequenced three chloroplast genomes of representative species from Bambusoideae and Ehrhartoideae and obtained 19 additional chloroplast genome sequences of other grasses from GenBank. Using sequences of 76 chloroplast protein-coding genes from the 22 grass species, we fully resolved the phylogeny of the BEP clade. Our results strongly supported the (B,P)E hypothesis, i.e., Bambusoideae and Pooideae are more closely related than Ehrhartoideae. This result was not biased by systematic or sampling errors and was impervious to phylogenetic methods or model specification. The divergence time estimate suggests that the initial diversification of the BEP clade into three subfamilies happened within a short time period (∼4. MY). The presence of these short internal branches may explain the inability of previous studies to achieve a confident resolution of the BEP clade. The combination of the sequences of the entire chloroplast genomes provided sufficient phylogenetic information to resolve the BEP phylogeny fully. These results provide a valuable evolutionary framework for comparative and functional genomic studies using the grass family as a model system. © 2011 Elsevier Inc.


Yang A.,CAS Institute of Botany | Yang A.,University of Chinese Academy of Sciences | Dai X.,CAS Institute of Botany | Zhang W.-H.,CAS Institute of Botany
Journal of Experimental Botany | Year: 2012

MYB-type transcription factors play a diverse role in plant development and response to abiotic stress. This study isolated a rice R2R3-type MYB gene, OsMYB2, and functionally characterized its role in tolerance to abiotic stress by generating transgenic rice plants with overexpressing and RNA interference OsMYB2. Expression of OsMYB2 was up-regulated by salt, cold, and dehydration stress. OsMYB2 was localized in the nucleus with transactivation activity. No difference in growth and development between the OsMYB2-overexpressing and wild-type plants was observed under normal growth conditions, but the OsMYB2-overexpressing plants were more tolerant to salt, cold, and dehydration stresses and more sensitive to abscisic acid than wild-type plants. The OsMYB2-overexpressing plants accumulated greater amounts of soluble sugars and proline than wild-type plants under salt stress. Overexpression of OsMYB2 enhanced up-regulation of genes encoding proline synthase and transporters. The OsMYB2-overexpressing plants accumulated less amounts of H2O2 and malondialdehyde. The enhanced activities of antioxidant enzymes, including peroxidase, superoxide dismutase, and catalase, may underlie the lower H2O2 contents in OsMYB2-overexpressing plants. There was greater up-regulation of stress-related genes, including OsLEA3, OsRab16A, and OsDREB2A, in the OsMYB2-overexpressing plants. Microarray analysis showed that expression of numerous genes involving diverse functions in stress response was altered in the OsMYB2-overexpressing plants. These findings suggest that OsMYB2 encodes a stress-responsive MYB transcription factor that plays a regulatory role in tolerance of rice to salt, cold, and dehydration stress. © 2012 The Author.


Chu Z.,CAS Chengdu Institute of Organic Chemistry | Chu Z.,University of Chinese Academy of Sciences | Feng Y.,CAS Chengdu Institute of Organic Chemistry
Soft Matter | Year: 2010

Wormlike micellar gels formed by concentrated 3-(N-erucamidopropyl-N,N- dimethyl ammonium) propanesulfonate (EDAS) solutions show both gel-like behavior and shear banding transitions. Such surfactant gels are strong viscoelastic fluids with ultra-long but finite relaxation time, instead of bulk gels with infinite zero-shear viscosity and relaxation time. We demonstrate for the first time the relationship between the yield stress and shear banding transition of the surfactant gels. © 2010 The Royal Society of Chemistry.


Lan Z.,CAS Institute of Botany | Lan Z.,University of Chinese Academy of Sciences | Bai Y.,CAS Institute of Botany
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2012

The increase in nutrient availability as a consequence of elevated nitrogen (N) deposition is an important component of global environmental change. This is likely to substantially affect the functioning and provisioning of ecosystem services by drylands, where water and N are often limited.We tested mechanisms of chronic N-enrichment-induced plant species loss in a 10-year field experiment with six levels of N addition rate. Our findings on a semi-arid grassland in Inner Mongolia demonstrated that: (i) species richness (SR) declined by 16 per cent even at low levels of additional N (1.75 gNm-2 yr-1), and 50-70% species were excluded from plots which received high N input (10.5-28 gNm-2 yr-1); (ii) the responses of SR and above-ground biomass (AGB) to N were greater in wet years than dry years; (iii) N addition increased the inter-annual variations in AGB, reduced the drought resistance of production and hence diminished ecosystem stability; (iv) the critical threshold for chronic N-enrichment-induced reduction in SR differed between common and rare species, and increased over the time of the experiment owing to the loss of the more sensitive species. These results clearly indicate that both abundance and functional trait-based mechanisms operate simultaneously on N-induced species loss. The low initial abundance and low above-ground competitive ability may be attributable to the loss of rare species. However, shift from below-ground competition to above-ground competition and recruitment limitation are likely to be the key mechanisms for the loss of abundant species, with soil acidification being less important. Our results have important implications for understanding the impacts of N deposition and global climatic change (e.g. change in precipitation regimes) on biodiversity and ecosystem services of the Inner Mongolian grassland and beyond.


Wei L.Q.,CAS Institute of Botany | Wei L.Q.,National Center for Plant Gene Research | Yan L.F.,CAS Institute of Botany | Yan L.F.,National Center for Plant Gene Research | And 3 more authors.
Genome Biology | Year: 2011

Background: Pollen development in flowering plants requires strict control of the gene expression program and genetic information stability by mechanisms possibly including the miRNA pathway. However, our understanding of the miRNA pathway in pollen development remains limited, and the dynamic profile of miRNAs in developing pollen is unknown.Results: Using next-generation sequencing technology, we pyrosequenced small RNA populations from rice uninucleate microspores to tricellular pollen and control sporophytic tissues at the genome-wide level. We identified 292 known miRNAs, including members of all 20 families conserved in plants, and 75 novel miRNAs. Of the 292 known miRNAs, 202 were expressed, with 103 enriched, in developing pollen. More than half of these novel miRNAs displayed pollen-or stage-specific expression. Furthermore, analyzing the 367 miRNAs and their predicted targets indicated that correlation in expression profiles of pollen-enriched known miRNAs and their targets significantly differs from that of sporophyte-enriched known miRNAs and their targets in some functional terms, while novel miRNAs appeared to negatively regulate their targets. Importantly, gene ontology abundance analysis demonstrated chromatin assembly and disassembly was important in the targets of bicellular pollen-expressed novel miRNAs. Principal component analysis revealed pollen of all three stages was discriminated from sporophytes, largely because of the novel and non-conserved known miRNAs.Conclusions: Our study, for the first time, revealed the differences in composition and expression profiles of miRNAs between developing pollen and sporophytes, with novel and non-conserved known miRNAs the main contributors. Our results suggest the important roles of the miRNA pathway in pollen development. © 2011 Wei et al.; licensee BioMed Central Ltd.


Bai H.,CAS National Center for Nanoscience and Technology | Bai H.,University of Chinese Academy of Sciences | Ju J.,CAS Beijing National Laboratory for Molecular | Ju J.,University of Chinese Academy of Sciences | And 2 more authors.
Advanced Materials | Year: 2012

Spider silk has been an attractive biopolymer since ancient times. Learning from both its excellent properties and spinning process, silk provides people with inspiration to develop functional fibers. Recently, inspired by shiny water droplets on a spider's web, we revealed that the capture silk of the cribellate spider would deform to have a special periodic spindle-knots structure and hence displayed unique wettability, making it efficient at directional water-collecting. This provides insights in designing functional fibers with unique wettability, by either creating special structures on the fiber surface, or modifying it with responsive molecules. These bioinspired functional fibers may find applications in many fields, such as water collection, smart catalysis, filtration, and sensing. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu Y.-J.,CAS Institute of Botany | Liu Y.-J.,University of Chinese Academy of Sciences | Han X.-M.,Beijing Forestry University | Ren L.-L.,CAS Institute of Botany | And 2 more authors.
Plant Physiology | Year: 2013

Plant glutathione S-transferases (GSTs) are multifunctional proteins encoded by a large gene family that play major roles in the detoxification of xenobiotics and oxidative stress metabolism. To date, studies on the GST gene family have focused mainly on vascular plants (particularly agricultural plants). In contrast, little information is available on the molecular characteristics of this large gene family in nonvascular plants. In addition, the evolutionary patterns of this family in land plants remain unclear. In this study, we identified 37 GST genes from the whole genome of the moss Physcomitrella patens, a nonvascular representative of early land plants. The 37 P. patens GSTs were divided into 10 classes, including two new classes (hemerythrin and iota). However, no tau GSTs were identified, which represent the largest class among vascular plants. P. patens GST gene family members showed extensive functional divergence in their gene structures, gene expression responses to abiotic stressors, enzymatic characteristics, and the subcellular locations of the encoded proteins. A joint phylogenetic analysis of GSTs from P. patens and other higher vascular plants showed that different class GSTs had distinct duplication patterns during the evolution of land plants. By examining multiple characteristics, this study revealed complex patterns of evolutionary divergence among the GST gene family in land plants.


Wang T.,CAS Changchun Institute of Applied Chemistry | Wang T.,University of Chinese Academy of Sciences | Bai J.,CAS Changchun Institute of Applied Chemistry | Jiang X.,CAS Changchun Institute of Applied Chemistry | And 2 more authors.
ACS Nano | Year: 2012

It is well-known that nanomaterials are capable of entering living cells, often by utilizing the cells' endocytic mechanisms. Passive penetration of the lipid bilayer may, however, occur as an alternative process. Here we have focused on the passive transport of small nanoparticles across the plasma membranes of red blood cells, which are incapable of endocytosis. By using fluorescence microscopy, we have observed that zwitterionic quantum dots penetrate through the cell membranes so that they can be found inside the cells. The penetration-induced structural changes of the lipid bilayer were explored by surface-enhanced infrared absorption spectroscopy and electrochemistry studies of model membranes prepared on solid supports with lipid compositions identical to those of red blood cell membranes. A detailed analysis of the infrared spectra revealed a markedly enhanced flexibility of the lipid bilayers in the presence of nanoparticles. The electrochemistry data showed that the overall membrane structure remained intact; however, no persistent holes were formed in the bilayers. © 2012 American Chemical Society.


Ng S.C.,NICTA | Zhang W.,University of Chinese Academy of Sciences | Zhang Y.,Imperial College London | Yang Y.,CAS Shanghai Institute of Microsystem and Information Technology | Mao G.,NICTA
IEEE Journal on Selected Areas in Communications | Year: 2011

IEEE 802.11p and 1609 standards are currently under development to support Vehicle-to-Vehicle and Vehicle-to-Infrastructure communications in vehicular networks. For infrastructure-based vehicular relay networks, access probability is an important measure which indicates how well an arbitrary vehicle can access the infrastructure, i.e. a base station (BS). On the other hand, connectivity probability, i.e. the probability that all the vehicles are connected to the infrastructure, indicates the service coverage performance of a vehicular relay network. In this paper, we develop an analytical model with a generic radio channel model to fully characterize the access probability and connectivity probability performance in a vehicular relay network considering both one-hop (direct access) and two-hop (via a relay) communications between a vehicle and the infrastructure. Specifically, we derive close-form equations for calculating these two probabilities. Our analytical results, validated by simulations, reveal the tradeoffs between key system parameters, such as inter-BS distance, vehicle density, transmission ranges of a BS and a vehicle, and their collective impact on access probability and connectivity probability under different communication channel models. These results and new knowledge about vehicular relay networks will enable network designers and operators to effectively improve network planning, deployment and resource management. © 2006 IEEE.


Zheng Z.,University of Chinese Academy of Sciences | Gao Q.,University of Chinese Academy of Sciences | Gao Q.,Beihang University
Journal of Power Sources | Year: 2011

Hierarchical porous carbons are prepared by an easy one-step process of carbonization and activation derived from phenol-formaldehyde resins, in which potassium hydroxide acts as both the catalyst of polymerization and the activation reagent. The simple one-step preparation saves the cost of carbons and leads to high yield. The porous carbons have high surface areas with abundant pore structures. The plenty of micropores and small mesopores increase the capacitance and make the electrolyte ions diffuse fast into the pores. These hierarchical porous carbons show high performance for supercapacitors possessing of the optimized capacitance of 234 F g-1 in aqueous electrolyte and 137 F g-1 in organic electrolyte with high capacitive retention. © 2010 Elsevier B.V.


Wang L.,CAS Institute of Biophysics | Zhang L.,CAS Institute of Biophysics | Zhang L.,University of Chinese Academy of Sciences | Niu Y.,CAS Institute of Biophysics | And 3 more authors.
Antioxidants and Redox Signaling | Year: 2014

Aims: Ero1 flavoproteins catalyze oxidative folding in the endoplasmic reticulum (ER), consuming oxygen and generating hydrogen peroxide (H 2O2). The ER-localized glutathione peroxidase 7 (GPx7) shows protein disulfide isomerase (PDI)-dependent peroxidase activity in vitro. Our work aims at identifying the physiological role of GPx7 in the Ero1α/PDI oxidative folding pathway and at dissecting the reaction mechanisms of GPx7. Results: Our data show that GPx7 can utilize Ero1α-produced H2O2 to accelerate oxidative folding of substrates both in vitro and in vivo. H2O2 oxidizes Cys57 of GPx7 to sulfenic acid, which can be resolved by Cys86 to form an intramolecular disulfide bond. Both the disulfide form and sulfenic acid form of GPx7 can oxidize PDI for catalyzing oxidative folding. GPx7 prefers to interact with the a domain of PDI, and intramolecular cooperation between the two redox-active sites of PDI increases the activity of the Ero1α/GPx7/PDI triad. Innovation: Our in vitro and in vivo evidence provides mechanistic insights into how cells consume potentially harmful H2O2 while optimizing oxidative protein folding via the Ero1α/GPx7/PDI triad. Cys57 can promote PDI oxidation in two ways, and Cys86 emerges as a novel noncanonical resolving cysteine. Conclusion: GPx7 promotes oxidative protein folding, directly utilizing Ero1α-generated H2O2 in the early secretory compartment. Thus, the Ero1α/GPx7/PDI triad generates two disulfide bonds and two H2O molecules at the expense of a single O2 molecule. © 2014 Mary Ann Liebert, Inc.


Chu Z.,CAS Chengdu Institute of Organic Chemistry | Chu Z.,University of Chinese Academy of Sciences | Feng Y.,CAS Chengdu Institute of Organic Chemistry
Chemical Communications | Year: 2011

A thermo-switchable surfactant gel with the property of gelation on heating was developed for the first time based on palmitylamidosulfobetaine. Micellar growth from globular aggregates to entangled worms upon heating is responsible for the thermal gelation. © 2011 The Royal Society of Chemistry.


Chu Z.,CAS Chengdu Institute of Organic Chemistry | Chu Z.,University of Chinese Academy of Sciences | Feng Y.,CAS Chengdu Institute of Organic Chemistry
ACS Sustainable Chemistry and Engineering | Year: 2013

There is no doubt that the surfactant and detergent industry is facing increasing severe environmental impact, and environmentally benign pathways are preferred to prepare these materials. We report herein a green route toward the preparation of vegetable-derived long-chain surfactants. The synthesis process possesses the following characteristics: bioresource-derived erucic acid (leftovers of rapeseed oil) was used as a starting material; no solvent was used and no chemical waste was produced; and high-yield products could be obtained in short reaction time. Compared with traditional surfactants bearing a saturated hydrophobic tail shorter than C18, the erucic acid-derived surfactants are more environmentally friendly because of their lower dosages in practical applications and the presence of the chemical degradable unsaturated bond and amido group in their molecular architecture. © 2012 American Chemical Society.


Guan J.,University of Chinese Academy of Sciences | Guan J.,Fudan University | Chen K.,CAS Institute of Policy and Management | Chen K.,Beihang University
Research Policy | Year: 2012

Although a large amount of past research has theorized about the character of national innovation systems (NISs), there has been limited process-oriented empirical investigation of this matter, possibly for methodological reasons. In this paper, we first propose a relational network data envelopment analysis (DEA) model for measuring the innovation efficiency of the NIS by decomposing the innovation process into a network with a two-stage innovation production framework, an upstream knowledge production process (KPP) and a downstream knowledge commercialization process (KCP). Although the concept of innovation efficiency is a simplification of the innovation process, it may be a useful tool for guiding policy decisions. We subsequently use a second-step partial least squares regression (PLSR) to examine the effects of policy-based institutional environment on innovation efficiency, considering statistical problems such as multicollinearity, small datasets and a small number of distribution assumptions. The hybrid two-step analytical procedure is used to consider 22 OECD (Organisation for Economic Co-operation and Development) countries. A significant rank difference, which indicates a non-coordinated relationship between upstream R&D (research and development) efficiency and downstream commercialization efficiency, is identified for most countries. The evidence also indicates that the overall innovation efficiency of an NIS is mainly subject to downstream commercial efficiency performance and that improving commercial efficiency should thus be a primary consideration in future innovation policy-making in most OECD countries. Finally, the results obtained using PLSR show that the various factors chosen to represent the embedded policy-based institutional environment have a significant influence on the efficiency performance of the two individual component processes, confirming the impact of public policy interventions undertaken by the government on the innovation performance of NISs. Based on these key findings, some country-specific and process-specific innovation policies have been suggested. © 2011 Elsevier B.V. All rights reserved.


Liu X.-L.,CAS Chengdu Institute of Organic Chemistry | Liu X.-L.,University of Chinese Academy of Sciences | Han W.-Y.,CAS Chengdu Institute of Organic Chemistry | Han W.-Y.,University of Chinese Academy of Sciences | And 2 more authors.
Organic Letters | Year: 2013

A wide range of structurally diverse 3,3′-thiopyrrolidonyl spirooxindoles bearing three contiguous stereogenic centers can be smoothly obtained via a domino Michael/cyclization reaction between 3-isothiocyanato oxindoles and 3-methyl-4-nitro-5-alkenyl-isoxazoles with commercially available quinine as the catalyst under mild conditions. The protocol is significantly characterized by high reactivity, a low catalyst loading (1 mol %), and an excellent diastereo- and enantioselectivity (up to >99:1 dr and 98% ee). © 2013 American Chemical Society.


Zheng X.-M.,CAS Institute of Botany | Zheng X.-M.,University of Chinese Academy of Sciences | Ge S.,CAS Institute of Botany | Ge S.,University of Chinese Academy of Sciences
Molecular Ecology | Year: 2010

Ecological divergence plays a prominent role in the process of speciation, but how divergence occurs in the face of gene flow is still less clear, and remains controversial among evolutionists. Here we investigated the nucleotide diversity, divergence and gene flow between Oryza nivara and O. rufipogon using sequences of seven chloroplast and nuclear loci. By analysing samples from 26 wild populations across the geographic ranges of the two species, we showed that both species were highly structured and O. rufipogon maintained a higher level of species-wide diversity than O. nivara. Notably, phylogenetic, amova and F ST analyses were unable to detect significant nucleotide differentiation between the two species. We estimated that the two species began to diverge at c. 0.16 million years ago. Our coalescent-based simulations strongly rejected the simple isolation model of zero migration between species, but rather provided unambiguous evidence of bidirectional gene flow between species, particularly from O. rufipogon to O. nivara. Our simulations also indicated that gene flow was recurrent during the divergence process rather than arising from secondary contact after allopatric divergence. In conjunction with different morphological and life-history traits and habitat preference in the two species, this study supports the hypothesis that these Oryza species are better treated as ecotypes that diverged quite recently and are still under the process of divergence. Importantly, we demonstrate the ecological divergence between O. rufipogon and O. nivara in the presence of significant gene flow, implying that natural selection plays a primary role in driving the divergence of the two Oryza species. © 2010 Blackwell Publishing Ltd.


Tao F.,Beihang University | Zhang L.,Beihang University | Lu K.,University of Chinese Academy of Sciences | Zhao D.,University of Michigan
Enterprise Information Systems | Year: 2012

In order to address the resource service optimal-selection (RSOS) and composition problem in manufacturing grid (MGrid) system and provide high-quality service to users, an MGrid RSOS and composition framework (MGrid-RSOSCF) is investigated in this study. The process of RSOS and composition is divided into the following five steps in MGrid-RSOSCF: (1) decomposing the submitted manufacturing task into several subtasks (i.e. single resource service requested task) if the submitted task is a multiple resource service requested task; (2) searching out the qualified resource service for each decomposed subtask and generating the corresponding candidate resource service set; (3) retrieving, evaluating and comparing the quality of service (QoS) for each candidate resource service, and provide data for service optimal-selection and composition -if the submitted task is a single resource service requested task; (4) evaluating synthetically the overall quality of each candidate resource service and ranking them, and selecting the optimal one for the task - if the submitted manufacturing task is an multiple resource service requested task; (5) selecting one candidate resource service from each candidate resource service set and constructing a new composite resource service according to the submitted task requirements, and collecting all the possible resource service composite execution paths (RSCEP) and selecting the optimal paths to execute the task. The proposed MGrid-RSOSCF consists of five layers and each layer provides the corresponding necessary services and algorithms to address one problem mentioned above. The five layers are: (1) T-layer, responsible for MGrid task decomposition; (2) S-layer, responsible for resource service match and search; (3) Q-layer, responsible for QoS processing; (4) O-layer, responsible for evaluating and ranking the candidate resource service and (5) C-layer is responsible for resource service composition and optimal-selection. The case study and comparison of performances of the algorithms demonstrate that the proposed methods are sound on success rate and executing efficiency. © 2012 Copyright Taylor and Francis Group, LLC.


Zhang C.,CAS Institute of Botany | Zhang C.,University of Chinese Academy of Sciences | Tian S.,CAS Institute of Botany
Food Chemistry | Year: 2010

Peach fruit (Prunus persica L. cv. Beijing 33) did not show symptoms of chilling injury in 0 °C-Air or 0 °C-CA, but did in 5 °C-Air after 21 d. The mechanisms by which 0 °C storage could activate chilling tolerance of peach fruit were investigated by analysing characteristics of plasma membrane. We found that peach fruit stored in 0 °C-Air and 0 °C-CA had much higher linolenic acid content and unsaturation degree of plasma membrane than did that in 5 °C-Air. In addition, the fruits stored in 0 °C-CA showed a higher membrane fluidity and membrane integrity than did that in 0 °C-Air, which was related to the accumulation of N-acylphosphatidylethanolamine (NAPE) of peach fruits stored in 0 °C-CA. Based on these results, it appears that a higher unsaturation degree of membrane lipid and NAPE accumulation are beneficial for maintaining membrane fluidity, leading to an enhanced tolerance of peach fruit to chilling stress. © 2009 Elsevier Ltd. All rights reserved.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: SSH-2007-1.2-01 | Award Amount: 3.33M | Year: 2009

INGINEUS addresses the evolution of global production networks (GPNs) into global innovation networks (GINs), and the impact this new process of global capitalism has on knowledge intensive activities in the EU. Global sourcing and assembly arrangements have been around for some three decades. They were principally based on efficiency considerations. Thus, multinational firms (MNCs) outsourced parts of production processes to manufacturers in Asia and other low-cost locations around the globe, while retaining the most knowledge intensive assets in the home country. This is no longer the case. MNCs increasingly scout the globe for locations where the right mix of local competences allows them to tap into sophisticated parts of value chains. This is not limited to advanced economies but more and more involves firms and regions in selected developing countries that position themselves as attractive knowledge-intensive locations in their own right. INGINEUS studies the determinants of this process and analyses its implications both for the EU and its emerging partner countries in the developing world. First, it looks at the changing strategies of MNCs and the conditions under which it is favourable for them to offshore R&D and other knowledge-intensive parts of their production process. Second, it focuses on the evolving local capabilities in selected developing countries that allow them to claim increasingly complex parts of global value chains at much higher levels of technological sophistication than hitherto. Third, it analyses the consequences of the formation of GINs in the global economy and differentiates among their static and dynamic effects on growth, employment, and competitiveness in the EU. Finally, based on these insights, it derives policy recommendations that would allow the EU to benefit from the positive features of this process while mitigating its adverse consequences.


Duan W.,CAS Institute of Atmospheric Physics | Yu Y.,CAS Qingdao Institute of Oceanology | Xu H.,CAS Institute of Atmospheric Physics | Zhao P.,CAS Institute of Atmospheric Physics | Zhao P.,University of Chinese Academy of Sciences
Climate Dynamics | Year: 2013

In the present paper, we explore the manner in which nonlinearities modulate El Niño events by investigating the optimal precursory disturbance for El Niño events in the Zebiak-Cane model. The initial anomalies of conditional nonlinear optimal perturbations (CNOPs) and linear singular vectors (LSVs) are investigated. The CNOPs evolve into stronger El Niño events than the LSVs and act as the optimal precursor for El Niño events. By examining the role of nonlinearities in El Niño events induced by CNOPs and LSVs, we determined that, when the initial anomalies of the CNOP and LSV structures are large, the nonlinearities enhance CNOP-El Niño events but suppress LSV-El Niño events. Nonlinearities in the Zebiak-Cane model arise from nonlinear temperature advection (NTA), sub-surface temperature parameterization (STP), and wind stress anomalies (WSA). Using these types of nonlinearities, we trace the approach of the nonlinearities modulating the CNOP- and LSV-El Niño events. The results demonstrate that nonlinearities that originate from NTA enhance both CNOP-El Niño events and LSV-El Niño events, while nonlinearities originating from STP and WSA suppress these events. For the CNOP-El Niño events, the enhancement effect of NTA is larger than the suppression effect of STP and WSA, resulting in the combined effect of the nonlinearities in the Zebiak-Cane model being an enhancement of the CNOP-El Niño events. However, for the LSV-El Niño events, the enhancement effect of NTA is smaller than the suppression effect of WSA and STP. Consequently, the combined effect of the nonlinearities in the Zebiak-Cane model suppresses the LSV-El Niño events. © 2012 The Author(s).


Cai Y.,University of Chinese Academy of Sciences | Wang Y.-T.,University of Chinese Academy of Sciences | Piao Y.-S.,University of Chinese Academy of Sciences | Piao Y.-S.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

In low-energy effective string theory and modified gravity theories, the propagating speed cT of primordial gravitational waves may deviate from unity. We find that the steplike variation of cT during slow-roll inflation may result in an oscillating modulation to the B-mode polarization spectrum, which can hardly be imitated by adjusting other cosmological parameters, and the intensity of the modulation is determined by the dynamics of cT. Thus provided that the foreground contribution is under control, high-precision cosmic microwave background (CMB) polarization observations will be able to put tight constraint on the variation of cT, and so the corresponding theories. © 2015 American Physical Society.


Wu Y.-L.,CAS Institute of Theoretical Physics | Wu Y.-L.,University of Chinese Academy of Sciences
International Journal of Modern Physics A | Year: 2014

To understand better the quantum structure of field theory and standard model in particle physics, it is necessary to investigate carefully the divergence structure in quantum field theories (QFTs) and work out a consistent framework to avoid infinities. The divergence has got us into trouble since developing quantum electrodynamics in 1930s. Its treatment via the renormalization scheme is satisfied not by all physicists, like Dirac and Feynman who have made serious criticisms. The renormalization group analysis reveals that QFTs can in general be defined fundamentally with the meaningful energy scale that has some physical significance, which motivates us to develop a new symmetry-preserving and infinity-free regularization scheme called loop regularization (LORE). A simple regularization prescription in LORE is realized based on a manifest postulation that a loop divergence with a power counting dimension larger than or equal to the space-time dimension must vanish. The LORE method is achieved without modifying original theory and leads the divergent Feynman loop integrals well-defined to maintain the divergence structure and meanwhile preserve basic symmetries of original theory. The crucial point in LORE is the presence of two intrinsic energy scales which play the roles of ultraviolet cutoff Mc and infrared cutoff μs to avoid infinities. As Mc can be made finite when taking appropriately both the primary regulator mass and number to be infinity to recover the original integrals, the two energy scales Mc and μs in LORE become physically meaningful as the characteristic energy scale and sliding energy scale, respectively. The key concept in LORE is the introduction of irreducible loop integrals (ILIs) on which the regularization prescription acts, which leads to a set of gauge invariance consistency conditions between the regularized tensor-type and scalar-type ILIs. An interesting observation in LORE is that the evaluation of ILIs with ultraviolet-divergence-preserving (UVDP) parametrization naturally leads to Bjorken-Drell's analogy between Feynman diagrams and electric circuits, which enables us to treat systematically the divergences of Feynman diagrams and understand better the divergence structure of QFTs. The LORE method has been shown to be applicable to both underlying and effective QFTs. Its consistency and advantages have been demonstrated in a series of applications, which includes the Slavnov-Taylor-Ward-Takahaski identities of gauge theories and supersymmetric theories, quantum chiral anomaly, renormalization of scalar interaction and power-law running of scalar mass, quantum gravitational effects and asymptotic free power-law running of gauge couplings. © 2014 World Scientific Publishing Company.


Gao S.,CAS Qingdao Institute of Oceanology | Gao S.,University of Chinese Academy of Sciences | Wang G.,CAS Qingdao Institute of Oceanology
Journal of Experimental Botany | Year: 2012

Porphyra yezoensis, a representative species of intertidal macro-algae, is able to withstand periodic desiccation at low tide but is submerged in seawater at high tide. In this study, changes in photosynthetic electron flow in P. yezoensis during desiccation and re-hydration were investigated. The results suggested that the cyclic electron flow around photosystem I (PSI) increased significantly during desiccation, continued to operate at times of severe desiccation, and showed greater tolerance to desiccation than the electron flow around PSII. In addition, PSI activity in desiccated blades recovered faster than PSII activity during re-hydration. Even though linear electron flow was suppressed by DCMU [3-(3',4'-dichlorophenyl)-1,1-dimethylurea], cyclic electron flow could still be restored. This process was insensitive to antimycin A and could be suppressed by dibromothymoquinone (DBMIB). The prolonged dark treatment of blades reduced the speed in which the cyclic electron flow around PSI recovered, suggesting that stromal reductants, including NAD(P)H, played an important role in the donation of electrons to PSI and were the main cause of the rapid recovery of cyclic electron flow in desiccated blades during re-hydration. These results suggested that cyclic electron flow in P. yezoensis played a significant physiological role during desiccation and rehydration and may be one of the most important factors allowing P. yezoensis blades to adapt to intertidal environments. © The Author [2012].


Ma D.-L.,CAS Changchun Institute of Applied Chemistry | Ma D.-L.,Jilin University | Cao Z.-Y.,Jilin University | Wang H.-G.,CAS Changchun Institute of Applied Chemistry | And 4 more authors.
Energy and Environmental Science | Year: 2012

A new hybrid nanostructure composed of three-dimensionally ordered macroporous (3DOM) FeF 3 and an homogenous coating of poly(3, 4-ethylenedioxythiophene) (PEDOT) is successfully synthesized using polystyrene (PS) colloidal crystals as hard template, and the coating of PEDOT is achieved through a novel in situ polymerization method. The special nanostructure provides a three-dimensional, continuous, and fast electronic and ionic path in the electrode. Surprisingly, the advantageous combination of 3DOM structure and homogenous coating of PEDOT endows the as-prepared hybrid nanostructures with a stable and high reversible discharge capacity up to 210 mA h g -1 above 2.0 V at room temperature (RT), and a good rate capability of 120 mA h g -1 at a high current density of 1 A g -1, which opens up new opportunities in the development of high performance next-generation lithium-ion batteries (LIBs). © 2012 The Royal Society of Chemistry.


Wang C.,National Oceanic and Atmospheric Administration | Li C.,CAS Institute of Atmospheric Physics | Li C.,University of Chinese Academy of Sciences | Mu M.,CAS Qingdao Institute of Oceanology | Duan W.,CAS Institute of Atmospheric Physics
Climate Dynamics | Year: 2013

The paper examines different impacts of eastern Pacific warm/cold (EPW/EPC) and central Pacific warm/cold (CPW/CPC) events on tropical cyclones (TCs) in the western North Pacific (WNP) by considering the early season of April-June (AMJ), the peak season of July-September (JAS) and the late season of October-December (OND). During AMJ, EPW (EPC) is associated with a significant increase of the TC genesis number in the southeastern (southwestern) sub-region of the WNP, but no class of El Niño-Southern Oscillation (ENSO) events shows a significant change in the TC lifetime and intensity. During JAS, EPW corresponds to an increase (decrease) of the TC genesis number in the southeastern (northwestern) sub-region, but CPW shows no significant change. EPC increases the TC genesis in the northwestern and northeastern sub-regions and decreases the genesis in the southwestern sub-region, whereas CPC suppresses the genesis in the southeastern sub-region. Both the lifetime and intensity of TCs are increased in EPW, but only a shortened lifetime is seen for CPC. During OND, EPW reduces the TC genesis in the southwestern and northwestern sub-regions, whereas CPW enhances the genesis in the southeastern sub-region. Over the South China Sea, CPW and CPC show a significant decrease and increase of the TC genesis, respectively. The TC lifetime is significantly longer in both EPW and CPW and shorter in EPC, and TCs tend to be more (less) intense in EPW (CPC). All of these variations are consistent with the development of ENSO-related SST anomalies during different seasons and are supported by distributions of the genesis potential index-a combination of large-scale oceanic and atmospheric factors that affect TC activity. TCs in the WNP mainly take the straight westward, northwestward and recurving tracks. During AMJ of EPW years, the TC steering flow patterns favor the recurving track and suppress the straight westward and northwestward tracks. During JAS, EPW is associated with the steering flows that are unfavorable for TCs to move northwestward or westward, whereas CPW favors the northwestward track and suppresses the straight westward track. The steering flow patterns during OND are similar to those during JAS, except that EPC may increase the possibility of the northwestward track. © 2012 Springer-Verlag (outside the USA).


Xue X.-J.,CAS Shanghai Institutes for Biological Sciences | Xue X.-J.,University of Chinese Academy of Sciences | Yuan X.-B.,CAS Shanghai Institutes for Biological Sciences
Molecular and Cellular Neuroscience | Year: 2010

The intermediate filament (IF) protein nestin is a widely accepted molecular marker for neural progenitor cells (NPCs), but its function during neurogenesis remains largely unknown. We found that in embryonic cortical NPCs down-regulation of the expression of nestin, but not its co-polymer IF protein vimentin, resulted in a G1 cell-cycle arrest and a severe reduction in the generation of neurons. Furthermore, down-regulating nestin expression in cultured cortical NPCs markedly suppressed their colony-formation ability and blocked the elevation of the cyclin D1/E protein level in response to the treatment with bFGF. Interestingly, nestin down-regulation caused a marked suppression in the activation of the phosphoinositide 3-kinase (PI3K) pathway but not the mitogen-activated protein kinase (MAPK) pathway in these NPCs. Moreover, defects in the proliferation of cortical NPCs caused by nestin down-regulation could be prevented by up-regulating PI3K activity. Thus, nestin is essential for the proliferation of NPCs by promoting the activation of PI3K in response to mitogenic growth factors. © 2010 Elsevier Inc.


Qian B.,CAS Qingdao Institute of Oceanology | Qian B.,University of Chinese Academy of Sciences | Wang J.,CAS Qingdao Institute of Oceanology | Zheng M.,CAS Qingdao Institute of Oceanology | Hou B.,CAS Qingdao Institute of Oceanology
Corrosion Science | Year: 2013

The inhibition effect of polyaspartic acid (PASP) and its synergistic effect with KI on mild steel corrosion in 0.5M H2SO4 solution are studied by weight loss and electrochemical methods. The inhibition efficiency increases with the concentration of PASP and increases further with the presence of 1mM KI. Result of the zero charge potential measurement shows that iodide ion promotes the film formation of PASP greatly. The mild steel surfaces after immersion test were analyzed using scanning electron microscopy and X-ray photoelectron spectroscopy. An adsorption model is proposed to elucidate the synergistic mechanism of synergistic effect. © 2013 Elsevier Ltd.


Tang Q.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Leng G.,University of Chinese Academy of Sciences | Groisman P.Y.,National Climatic Data Center
Journal of Climate | Year: 2012

A pronounced summer warming is observed in Europe since the 1980s that has been accompanied by an increase in the occurrence of heat waves. Water deficit that strongly reduces surface latent cooling is a widely accepted explanation for the causes of hot summers. The authors show that the variance of European summer temperature is partly explained by changes in summer cloudiness. Using observation-based products of climate variables, satellite-derived cloud cover, and radiation products, the authors show that, during the 1984-2007 period, Europe has become less cloudy (except northeastern Europe) and the regions east of Europe have become cloudier in summer daytime. In response, the summer temperatures increased in the areas of total cloud cover decrease and stalled or declined in the areas of cloud cover increase. Trends in the surface shortwave radiation are generally positive (negative) in the regions with summer warming (cooling or stalled warming), whereas the signs of trends in top-of-atmosphere (TOA) reflected shortwave radiation are reversed. The authors' results suggest that total cloud cover is either the important local factor influencing the summer temperature changes in Europe or a major indicator of these changes. © 2012 American Meteorological Society.


Geng C.-Q.,National Tsing Hua University | Geng C.-Q.,National Center for Theoretical science | Huang D.,National Tsing Hua University | Tang Y.,National Center for Theoretical science | And 2 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

A new boson around 125 GeV without specific spin has been observed by both ATLAS and CMS at the LHC. Since its decay into a diphoton excludes the spin-1 case by the Landau-Yang theorem, it leaves 0 or 2 as the possible lowest spin for the new boson. Instead of the well-established spin-0 Higgs-like boson, we take this new boson to be a spin-2 massive graviton-like particle denoted as G, which exists copiously in extra-dimension theories, and concentrate on its phenomenology. In particular, we calculate the three-body decays of G→Vff̄' with V and f(') the gauge boson and fermions in the standard model (SM) and compare our results with those of the SM Higgs boson. The couplings between G and Vs are also estimated by fitting the data. A new observable that can distinguish G from the Higgs is proposed. © 2013 Elsevier B.V.


Chen L.-B.,University of Chinese Academy of Sciences | Qiao C.-F.,University of Chinese Academy of Sciences | Qiao C.-F.,CAS Institute of Theoretical Physics | Zhu R.-L.,University of Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

To ascertain the new boson with mass near 125 GeV observed recently by ATLAS and CMS Collaborations to be the Standard Model Higgs, and to determine its intrinsic properties, more measurements on its various decay channels are still necessary. In this work we reanalyze the processes of the Standard Model Higgs radiative decays to lepton pairs. We find that when photon and leptons are hard, that is possessing energies larger than 1 GeV, the branching fractions of H→ℓℓ-γ (ℓ=e or μ) processes are about two-thirds of the H→μ+μ- process. Since the lepton pair yields of the radiative processes mainly come from the Z-boson conversion, which will greatly suppress the backgrounds, we believe the signal should be observable in presently accumulated data or in the next run of the LHC experiment, provided the Standard Model Higgs is indeed light. © 2013 Elsevier B.V.


Zhang K.-J.,Nanjing University | Zhang Y.-X.,University of Chinese Academy of Sciences | Tang X.-C.,University of Chinese Academy of Sciences | Xia B.,Sun Yat Sen University
Earth-Science Reviews | Year: 2012

The elevation of the Tibetan plateau is a revolutionary event in the Earth history, which resulted in change not only of Cenozoic regional and global climate but also of monsoon intensity. A critical aspect for the development of the Tibetan plateau that remains open to intense debate is whether the collision among the Tibetan continental blocks or the subduction of the Tethys prior to the Indo-Asian collision in the Cenozoic contributed to the plateau growth. We propose here that an Andean-type orogen could have been present in southern Tibet from the Jurassic to Early Cretaceous, but collapsed during the Middle Cretaceous, based on a synthesis of existing structural, sedimentary, geochronological, and geochemical data. The orogeny is marked by north-verging Jurassic-Early Cretaceous thrusting in the Lhasa block, a result of flat subduction of the Yarlung-Zangpo Neo-tethys that is recorded by a narrow belt of 205-174. Ma adakitic rocks along the southernmost margin of the Lhasa block. Denudation of the orogen produced a thick (up to 15. km) sequence of Jurassic turbidites and molasse-type sediments on the northern Lhasa block. Widespread Middle Cretaceous (135-100. Ma) postorogenic, strongly peraluminous to calc-alkaline, magmatism and extensional deformation in the Lhasa block and an extensive marine transgression in Tibet indicate that the orogen broke down due to extension resulting from lithosphere delamination and asthenosphere upwelling. Meanwhile, the north-dipping subduction of the Bangong Meso-tethys produced a wide Jurassic-Middle Cretaceous magmatic arc along the southern margin of the Qiangtang block. Findings of 132-108. Ma-aged ophiolites rich with Middle Cretaceous radiolarians in central Tibet indicate that the Bangong Meso-tethys did not close until the Late Cretaceous. Repeated flat slab subduction of the Yarlung-Zangpo Neo-tethys occurred during the Late Cretaceous (90-78. Ma) as indicated by the adakites in the southernmost Lhasa block, which, together with the ongoing Qiangtang-Lhasa collision, could have contributed to the growth of the Tibetan plateau. © 2012 Elsevier B.V.


Qin S.,CAS Yantai Institute of Coastal Zone Research | Lin H.,CAS Qingdao Institute of Oceanology | Lin H.,University of Chinese Academy of Sciences | Jiang P.,CAS Qingdao Institute of Oceanology
Biotechnology Advances | Year: 2012

Algae are a component of bait sources for animal aquaculture, and they produce abundant valuable compounds for the chemical industry and human health. With today's fast growing demand for algae biofuels and the profitable market for cosmetics and pharmaceuticals made from algal natural products, the genetic engineering of marine algae has been attracting increasing attention as a crucial systemic technology to address the challenge of the biomass feedstock supply for sustainable industrial applications and to modify the metabolic pathway for the more efficient production of high-value products. Nevertheless, to date, only a few marine algae species can be genetically manipulated. In this article, an updated account of the research progress in marine algal genomics is presented along with methods for transformation. In addition, vector construction and gene selection strategies are reviewed. Meanwhile, a review on the progress of bioreactor technologies for marine algae culture is also revisited. © 2012 Elsevier Inc.


Liu F.,CAS Chengdu Institute of Optics and Electronics | Liu F.,University of Chinese Academy of Sciences | Wu Y.,CAS Chengdu Institute of Optics and Electronics | Wu F.,CAS Chengdu Institute of Optics and Electronics
Optics Express | Year: 2015

We propose a novel phase shifting interferometry from two normalized interferograms with random tilt phase-shift. The determination of tilt phase-shift is performed by extracting the tilted phase-shift plane from the phase difference of two normalized interferograms, and with the calculated tilt phase-shift value the phase distribution can be retrieved from the two normalized frames. By analyzing the distribution of phase difference and utilizing special points fitting method, the tilted phase-shift plane is extracted in three different cases, which relate to different magnitudes of tilts. Proposed method has been applied to simulations and experiments successfully and the satisfactory results manifest that proposed method is of high accuracy and high speed compared with the three step iterative method. Additionally, both open and closed fringe can be analyzed with proposed method. What's more, it cannot only eliminate the small tiltshift error caused by slight vibration in phase-shifting interferometry, but also detect the large tilt phase-shift in phase-Tilting interferometry. Thus, it will relaxes the requirements on the accuracy of phase shifter, and the costly phase shifter may even be useless by applying proposed method in high amplitude vibrated circumstance to achieve high-precision analysis. ©2015 Optical Society of America.


Liu Z.-G.,University of Chinese Academy of Sciences | Guo Z.-K.,CAS Institute of Theoretical Physics | Piao Y.-S.,University of Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Recent Planck data show the anomalies of cosmic microwave background (CMB) fluctuations on large angular scales, which confirms the early observations by WMAP. We continue studying an inflationary model, in which before the slow-roll inflation the universe is in a contracting phase, and fit the model with the Planck data. We show that this model may generate not only the power deficit at low l, but also a large hemispherical power asymmetry in the CMB. We also discuss the implication of the result to the eternal inflation scenario. © 2013 American Physical Society.


Bu Y.,CAS Institute of Theoretical Physics | Bu Y.,University of Chinese Academy of Sciences | Bu Y.,Max Planck Institute for Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We explore the effect of a magnetic field on the electromagnetic signature in QCD-like plasma by taking the AdS/CFT approach. Concretely, we choose two QCD gravity dual models to do comparative studies: the D4/D6 and D3/D7 models. The magnetic field is simulated by a spatial component of the flavor U(1) gauge field in the bulk side. For both models, we plot the spectral function and photoemission rate for lightlike momenta as well as the ac conductivity. Due to the presence of the magnetic field, the rotational symmetry is partially broken. Therefore, we plot the spectral function and photoemission rate with spatial momentum parallel or perpendicular to the magnetic field, respectively. We find that the magnetic field induces an anisotropic feature in the electromagnetic signature. To be specific, when the emitted photons from the plasma are moving along the magnetic field, the electromagnetic signature is weakened as the magnetic field is increasing; on the contrary, when the produced photons move perpendicular to the magnetic field, the magnetic field has the effect of amplifying the electromagnetic signature. This should have a relationship with the anisotropic feature of the photon signal observed in heavy-ion collision experiments. This anisotropic characteristic can also be observed in the ac conductivity of the holographic plasma. In the infrared regime of the frequency, the magnetic field suppresses the ac conductivity (along the direction perpendicular to the magnetic field) and likely gives a pseudogap structure. However, the ac conductivity along the magnetic field is enhanced due to the presence of the magnetic field. © 2013 American Physical Society.


Qiao C.-F.,University of Chinese Academy of Sciences | Qiao C.-F.,CAS Institute of Theoretical Physics | Zhu R.-L.,University of Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We study the semileptonic differential decay rates of the Bc meson to S-wave charmonia, ηc, and J/Ψ at next-to-leading order accuracy in the framework of nonrelativistic QCD. In the heavy quark limit, mb→∞, we obtain analytically the asymptotic expression for the ratio of the next-to-leading order form factor to the leading-order form factor. Numerical results show that the convergence of the ratio is perfect. At the maximum recoil region, we analyze the differential decay rates in detail with various input parameters and polarizations of J/ψ, which can now be checked in the LHCb experiment. Phenomenologically, the form factors are extrapolated to the minimal recoil region, and then the Bc-to-charmonium semileptonic decay rates are estimated. © 2013 American Physical Society.


Ma T.,CAS Institute of Geology and Geophysics | Ma T.,University of Chinese Academy of Sciences | Zhang Z.,CAS Institute of Geology and Geophysics
Bulletin of the Seismological Society of America | Year: 2014

Irregular surfaces cause a number of problems for seismic processing and interpretation. The problems lie in the proper treatment of topography in the first-arrival travel-time calculation and ray-path tracing, both of which are subject to preconditions in ray-based seismogram synthesis, seismic tomography, and seismic migration calculations. Two treatment schemes for irregular surfaces have been used previously: (1) model expansion with the irregular surface treated as an inner discontinuity, and (2) flattening of the irregular surface using a transformation between curvilinear and Cartesian coordinates, while maintaining it as a free surface. In the first approach, first-arrival travel times can be calculated using an eikonal equation solver, and rays are traced backward from the receiver to the source along the direction of the gradient of the travel-time field. In the second scheme, a topography-dependent eikonal equation is used to calculate irregular-surface first-arrival travel times.We present a ray-path tracing scheme for irregular surfaces, which applies a travel-time field calculated using a topography-dependent eikonal equation. The scheme is realized using travel-time gradients in curvilinear coordinates. The validity of the scheme for tracing ray paths in the presence of irregular topography is illustrated by five models containing differing degrees of topographical complexity. Comparison of ray paths and first-arrival travel times between the two irregular-surface treatment schemes suggests the topography- flattened scheme avoids the difficulties of both discretizing the irregular surface and the velocity selection of the infill medium in the model expansion scheme. For the treatment of the inner discontinuity by model expansion, there is a possibility that ray paths will be traced outside the real physical model. Using the topography-dependent eikonal equation solver with our ray-path tracing scheme should provide an efficient means of dealing with irregular surfaces, which could be applied in the fields of seismic tomography, seismic migration, and tomographic static correction.


Guo Y.,CAS National Center for Nanoscience and Technology | Guo Y.,CAS Chengdu Institute of Biology | Guo Y.,University of Chinese Academy of Sciences | Wang Z.,CAS National Center for Nanoscience and Technology | And 2 more authors.
Carbon | Year: 2013

We have developed a simple, one-step hydrothermal method for the synthesis of highly fluorescent carbon nanoparticles (F-CNPs) with a high quantum yield (68%) and good photostability. The method requires less reaction time and a lower reaction temperature as compared with the previous reported methods. The as-prepared F-CNPs exhibit excellent emission property and high stability, as well as excitation-independent emission behavior. Moreover, it is attractive that F-CNPs can be used as an effective fluorescent probe for the detection of mercury ions with good selectivity and sensitivity in an aqueous solution. © 2012 Elsevier Ltd. All rights reserved.


Zeng H.,CAS Institute of Atmospheric Physics | Zeng H.,University of Chinese Academy of Sciences | Jia G.,CAS Institute of Atmospheric Physics | Epstein H.,University of Virginia
Environmental Research Letters | Year: 2011

Phenology of vegetation is a sensitive and valuable indicator of the dynamic responses of terrestrial ecosystems to climate change. Therefore, to better understand and predict ecosystems dynamics, it is important to reduce uncertainties in detecting phenological changes. Here, changes in phenology over the past several decades across the northern high-latitude region (60°N) were examined by calibrating and analyzing time series of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Very High Resolution Radiometer (AVHRR). Over the past decade (200010), an expanded length of the growing season (LOS) was detected by MODIS, largely due to an earlier start of the growing season (SOS) by 4.7 days per decade and a delayed end of the growing season (EOS) by 1.6 days per decade over the northern high latitudes. There were significant differences between North America and Eurasia in phenology from 2000 to 2010 based on MODIS data (SOS: df=21, F=49.02, p<0.0001; EOS: df=21, F=49.25, p<0.0001; LOS: df=21, F=79.40, p<0.0001). In northern America, SOS advanced by 11.5 days per decade, and EOS was delayed by 2.2 days per decade. In Eurasia, SOS advanced by 2.7 days per decade, and EOS was delayed by 3.5 days per decade. SOS has likely advanced due to the warming Arctic during April and May. Our results suggest that in recent decades the longer vegetation growing seasons can be attributed to more advanced SOS rather than delayed EOS. AVHRR detected longer LOS over the past three decades, largely related to delayed EOS rather than advanced SOS. These two datasets are significantly different in key phenological parameters (SOS: df=17, F=14.63, p=0.0015; EOS: df=17, F=38.69, p<0.0001; LOS: df=17, F=16.47, p=0.0009) from 2000 to 2008 over the northern high latitudes. Thus, further inter-calibration between the sensors is needed to resolve the inconsistency and to better understand long-term trends of vegetation growth in the Arctic. © 2011 IOP Publishing Ltd.


Huang Q.-G.,CAS Institute of Theoretical Physics | Piao Y.-S.,University of Chinese Academy of Sciences | Zhou S.-Y.,University of Nottingham
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

It has recently been shown that the graviton can consistently gain a constant mass without introducing the Boulware-Deser ghost. We propose a gravity model where the graviton mass is set by a scalar field and prove that this model is free of the Boulware-Deser ghost by analyzing its constraint system and showing that two constraints arise. We also initiate the study of the model's cosmic background evolution and tentatively discuss possible cosmological implications of this model. In particular, we consider a simple scenario where the scalar field setting the graviton mass is identified with the inflaton and the graviton mass evolves from a high to a low energy scale, giving rise to the current cosmic acceleration. © 2012 American Physical Society.


Li L.,CAS Changchun Institute of Applied Chemistry | Li L.,Jilin University | Wu Z.,CAS Changchun Institute of Applied Chemistry | Wu Z.,University of Chinese Academy of Sciences | And 3 more authors.
Energy and Environmental Science | Year: 2014

To meet the rapid development of flexible, portable, and wearable electronic devices, extensive efforts have been devoted to develop matchable energy storage and conversion systems as power sources, such as flexible lithium-ion batteries (LIBs), supercapacitors (SCs), solar cells, fuel cells, etc. Particularly, during recent years, exciting works have been done to explore more suitable and effective electrode/electrolyte materials as well as more preferable cell configuration and structural designs to develop flexible power sources with better electrochemical performance for integration into flexible electronics. An overview is given for these remarkable contributions made by the leading scientists in this important and promising research area. Some perspectives for the future and impacts of flexible energy storage and conversion systems are also proposed. © The Royal Society of Chemistry 2014.


Liu Z.-G.,University of Chinese Academy of Sciences | Guo Z.-K.,CAS Institute of Theoretical Physics | Piao Y.-S.,University of Chinese Academy of Sciences
European Physical Journal C | Year: 2014

Recent Planck measurements show some CMB anomalies on large angular scales, which confirms the early observations by WMAP. We show that an inflationary model, in which before the slow-roll inflation the Universe is in a superinflationary phase, can generate a large-scale cutoff in the primordial power spectrum, which may account for not only the power suppression on large angular scales, but also a large dipole power asymmetry in the CMB. We discuss an implementation of our model in string theory. © 2014, The Author(s).


Feng K.,University of Chinese Academy of Sciences | Qiu T.,National Taiwan University | Qiu T.,Central China Normal University | Piao Y.-S.,University of Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We show a curvaton model, in which the curvaton has a nonminimal derivative coupling to gravity. Thanks to such a coupling, we find that the scale-invariance of the perturbations can be achieved for arbitrary values of the equation-of-state of background, provided that it is nearly a constant. We also discussed about tensor perturbations, the local non-Gaussianities generated by the nonminimal derivative coupling curvaton model, as well as the adiabatic perturbations which are transferred from the field perturbations during the curvaton decay. © 2014 The Authors.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Zhao Z.K.,CAS Dalian Institute of Chemical Physics | Zhao Z.K.,Dalian National Laboratory for Clean Energy
Bioresource Technology | Year: 2010

Production of 5-hydroxymethylfurfural (HMF) and furfural from lignocellulosic biomass was studied in ionic liquid in the presence of CrCl3 under microwave irradiation. Corn stalk, rice straw and pine wood treated under typical reaction conditions produced HMF and furfural in yields of 45-52% and 23-31%, respectively, within 3 min. This method should be valuable to facilitate energy-efficient and cost-effective conversion of biomass into biofuels and platform chemicals. © 2009 Elsevier Ltd. All rights reserved.


Song Y.,University of Chinese Academy of Sciences | Chen Y.,Jilin University | Feng L.,University of Chinese Academy of Sciences | Ren J.,University of Chinese Academy of Sciences | Qu X.,University of Chinese Academy of Sciences
Chemical Communications | Year: 2011

We report here a folic acid conjugated graphene-hemin composite for selective, quantitative and fast colorimetric detection of cancer cells based on the peroxidase-like activity. © 2011 The Royal Society of Chemistry.


Cheng T.-L.,CAS Shanghai Institutes for Biological Sciences | Cheng T.-L.,University of Chinese Academy of Sciences | Wang Z.,University of Washington | Liao Q.,CAS Shanghai Institutes for Biological Sciences | And 4 more authors.
Developmental Cell | Year: 2014

Loss- and gain-of-function mutations of the X-linked gene MECP2 (methyl-CpG binding protein 2) lead tosevere neurodevelopmental disorders in humans, such as Rett syndrome (RTT) and autism. MeCP2 ispreviously known as a transcriptional repressor bybinding to methylated DNA and recruiting histone deacetylase complex (HDAC). Here, we report that MeCP2 regulates gene expression posttranscriptionally by suppressing nuclear microRNA processing. We found that MeCP2 binds directly to DiGeorge syndrome critical region 8 (DGCR8), a critical component of the nuclear microRNA-processing machinery, and interferes with the assembly of Drosha andDGCR8 complex. Protein targets of MeCP2-suppressed microRNAs include CREB, LIMK1, and Pumilio2, which play critical roles in neural development. Gain of function of MeCP2 strongly inhibits dendritic and spine growth, which depends on the interaction of MeCP2 and DGCR8. Thus, control of microRNA processing via direct interaction with DGCR8 represents a mechanism for MeCP2 regulation of gene expression and neural development. © 2014 Elsevier Inc.


Zhang S.-B.,CAS Chengdu Institute of Biology | Zhang S.-B.,University of Chinese Academy of Sciences | Wu Z.-L.,CAS Chengdu Institute of Biology
Bioresource Technology | Year: 2011

Feruloyl esterases are key enzymes involved in the complete hydrolysis of hemicellulose. In order to improve the thermostability of feruloyl esterase A (FaeA) from Aspergillus niger CIB 423.1, the PoPMuSiC algorithm was applied to predict the folding free energy change (ΔΔG) of amino acid substitutions. Four amino acid substitutions (S92A, D93G, D174A and S187F) were introduced into the enzyme by site-directed mutagenesis and the enzymes were produced in Pichia pastoris KM71. No obvious changes in thermal stability resulted from substitutions S92A and D174A, but, compared to the wild-type enzyme which has a half-life of inactivation of 8min, the half-lives of enzymes with a D93G or S187F substitution increased to 9.4 and 60.5min, respectively. The double mutant D93G/S187F displayed a synergistic effect with a t 1/2 value of 77.0min. It also displayed over 10-fold increase in catalytic turnover frequency. The result will benefit further investigation of the thermostability of feruloyl esterase A. © 2010 Elsevier Ltd.


Zhou Y.,CAS Beijing National Laboratory for Molecular | Zhou Y.,University of Chinese Academy of Sciences | Guo W.,CAS Beijing National Laboratory for Molecular | Cheng J.,Tsinghua University | And 3 more authors.
Advanced Materials | Year: 2012

Stimuli-responsive nanofluidic systems in room temperature ionic liquids (RTILs). The nanofluidic device can withstand high temperatures up to 200 °C, in which conventional water-based smart materials and nanodevices are invalid. The smart nanopores can be "irreversibly" turned off above the transition temperature of ca. 120-150 °C, actuated by the conformational change of the chemically-modified polymer brushes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xu-Ri,CAS Institute of Tibetan Plateau Research | Prentice I.C.,Macquarie University | Prentice I.C.,Grantham Institute for Climate Change | Spahni R.,University of Bern | Niu H.S.,University of Chinese Academy of Sciences
New Phytologist | Year: 2012

Ecosystem nitrous oxide (N2O) emissions respond to changes in climate and CO2 concentration as well as anthropogenic nitrogen (N) enhancements. Here, we aimed to quantify the responses of natural ecosystem N2O emissions to multiple environmental drivers using a process-based global vegetation model (DyN-LPJ). We checked that modelled annual N2O emissions from nonagricultural ecosystems could reproduce field measurements worldwide, and experimentally observed responses to step changes in environmental factors. We then simulated global N2O emissions throughout the 20th century and analysed the effects of environmental changes. The model reproduced well the global pattern of N2O emissions and the observed responses of N cycle components to changes in environmental factors. Simulated 20th century global decadal-average soil emissions were c. 8.2-9.5 Tg N yr-1 (or 8.3-10.3 Tg N yr-1 with N deposition). Warming and N deposition contributed 0.85 ± 0.41 and 0.80 ± 0.14 Tg N yr-1, respectively, to an overall upward trend. Rising CO2 also contributed, in part, through a positive interaction with warming. The modelled temperature dependence of N2O emission (c. 1 Tg N yr-1 K-1) implies a positive climate feedback which, over the lifetime of N2O (114 yr), could become as important as the climate-carbon cycle feedback caused by soil CO2 release. See also the Commentary by Del Grosso and Parton. © 2012 New Phytologist Trust.


Duan C.,University of Chinese Academy of Sciences | Luo M.,University of Chinese Academy of Sciences | Xing X.,Tsinghua University
Bioresource Technology | Year: 2011

Methanol was produced from methane with a high conversion rate using a high cell density process with Methylosinus trichosporium OB3b in the presence of a high concentration of phosphate buffer. More than 1.1g/L methanol accumulated in the reaction media under optimized reaction conditions (17g dry cell/L, 400mmol/L phosphate, and 10mmol/L MgCl 2) in the presence of 20mmol/L sodium formate. The conversion rate of methane was over 60%. About 0.95g/L methanol was produced when the biotransformation was carried out in a membrane aerated reactor into which methane and oxygen were introduced via two separate dense silicone tubing. Our results provide an efficient method and a promising process for high-rate conversion of methane to methanol. © 2011 Elsevier Ltd.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhao Z.,Dalian National Laboratory for Clean Energy
Bioresource Technology | Year: 2011

Production of 5-hydroxymethylfurfural (HMF) from glucose was studied in ionic liquids in the presence of hydroxyapatite supported chromium chloride (Cr-HAP) using oil-bath heating and microwave irradiation (MI). Compared with oil-bath heating, the MI way obviously increased HMF yield and reduced the reaction time from days to several minutes. A maximum HMF yield of 40% was obtained from the dehydration of glucose under MI in 2.5. min. This method is potential as an energy-efficient and cost-effective approach for the conversion of biomass into platform chemicals. © 2010 Elsevier Ltd.


Wu Y.-L.,CAS Institute of Theoretical Physics | Wu Y.-L.,University of Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

Treating the gravitational force on the same footing as the electroweak and strong forces, we present a quantum field theory of gravity based on spin and scaling gauge symmetries. A biframe spacetime is initiated to describe such a quantum gravity theory. The gravifield sided on both locally flat noncoordinate spacetime and globally flat Minkowski spacetime is an essential ingredient for gauging global spin and scaling symmetries. The locally flat gravifield spacetime spanned by the gravifield is associated with a noncommutative geometry characterized by a gauge-type field strength of the gravifield. A coordinate-independent and gauge-invariant action for the quantum gravity is built in the gravifield basis. In the coordinate basis, we derive equations of motion for all quantum fields including the gravitational effect and obtain basic conservation laws for all symmetries. The equation of motion for the gravifield tensor is deduced in connection directly with the total energy-momentum tensor. When the spin and scaling gauge symmetries are broken down to a background structure that possesses the global Lorentz and scaling symmetries, we obtain exact solutions by solving equations of motion for the background fields in a unitary basis. The massless graviton and massive spinon result as physical quantum degrees of freedom. The resulting Lorentz-invariant and conformally flat background gravifield spacetime is characterized by a cosmic vector with a nonzero cosmological mass scale. The evolving Universe is, in general, not isotropic in terms of conformal proper time. The conformal size of the Universe becomes singular at the cosmological horizon and turns out to be inflationary in light of cosmic proper time. A mechanism for quantum scalinon inflation is demonstrated such that it is the quantum effect that causes the breaking of global scaling symmetry and generates the inflation of the early Universe, which is ended when the evolving vacuum expectation value of the scalar potential gets a minimal. Regarding the gravifield as a Goldstone-like field that transmutes the local spin gauge symmetry into the global Lorentz symmetry with a hidden general coordinate invariance, a spacetime gauge field is constructed from the spin gauge field that becomes a hidden gauge field. The bosonic gravitational interactions are described by the Goldstone-like gravimetric field and spacetime gauge field. Two types of gravity equation result; one is as the extension to Einstein's equation of general relativity, and the other is a new one that characterizes spinon dynamics. The Einstein theory of general relativity is considered to be an effective low-energy theory. © 2016 American Physical Society.


Ding R.,CAS Changchun Institute of Applied Chemistry | Ding R.,University of Chinese Academy of Sciences | Ding R.,Jilin University | Qi L.,CAS Changchun Institute of Applied Chemistry | And 2 more authors.
Nanoscale | Year: 2014

Mesoporous spinel nickel cobaltite (NiCo2O4) nanostructures were synthesized via a facile chemical deposition method coupled with a simple post-annealing process. The physicochemical properties were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and nitrogen sorption measurements. The electrocatalytic performances were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) tests. The obtained NiCo 2O4 materials exhibit typical agglomerate mesoporous nanostructures with a large surface area (190.1 m2 g-1) and high mesopore volume (0.943 cm3 g-1). Remarkably, the NiCo2O4 shows much higher catalytic activity, lower overpotential, better stability and greater tolerance towards urea electro-oxidation compared to those of cobalt oxide (Co3O 4) synthesized by the same procedure. The NiCo2O 4 electrode delivers a current density of 136 mA cm-2 mg-1 at 0.7 V (vs. Hg/HgO) in 1 M KOH and 0.33 M urea electrolytes accompanied with a desirable stability. The impressive electrocatalytic activity is largely ascribed to the high intrinsic electronic conductivity, superior mesoporous nanostructures and rich surface Ni active species of the NiCo 2O4 materials, which can largely boost the interfacial electroactive sites and charge transfer rates for urea electro-oxidation, indicating promising applications in future wastewater remediation, hydrogen production and fuel cells. © 2013 The Royal Society of Chemistry.


Chen L.,CAS Nanjing Institute of Geology and Palaeontology | Chen L.,University of Chinese Academy of Sciences | Xiao S.,Virginia Polytechnic Institute and State University | Pang K.,CAS Nanjing Institute of Geology and Palaeontology | And 4 more authors.
Nature | Year: 2015

Phosphorites of the EdiacaranDoushantuo Formation (600 million yearsold) yield spheroidalmicrofossilswith a palintomic cell cleavage pattern1,2. These fossils have been variously interpreted as sulphuroxidizing bacteria3, unicellular protists4, mesomycetozoean-like holozoans5, green algae akin to Volvox6,7, and blastula embryos of early metazoans1,2,8-10 or bilaterian animals11,12. However, their complete life cycle is unknownand it is uncertain whether they had a cellularly differentiated ontogenetic stage, making it difficult to test their various phylogenetic interpretations. Here we describe new spheroidal fossils from black phosphorites of the Doushantuo Formation that have been overlooked in previous studies.These fossils represent later developmental stages of previouslypublishedblastula-like fossils, and they show evidence for cell differentiation, germ-soma separation, and programmed cell death. Their complexmulticellularity is inconsistent with a phylogenetic affinity with bacteria,unicellular protists, or mesomycetozoean-like holozoans. Available evidence also indicates that the Doushantuo fossils are unlikely crown-group animals or volvocine green algae.Weconclude that an affinity with cellularly differentiated multicellular eukaryotes, including stem-group animals or algae, is likely butmore data are needed to constrain further the exact phylogenetic affinity of the Doushantuo fossils. © 2014 Macmillan Publishers Limited. All rights reserved.


Li Y.,CAS Qingdao Institute of Oceanology | Li Y.,University of Chinese Academy of Sciences | Wang F.,CAS Qingdao Institute of Oceanology
Journal of Oceanography | Year: 2012

Newly formed North Pacific Tropical Water (NPTW) is carried to the Philippine Sea (PS) by the North Equatorial Current (NEC) as a subsurface salinity maximum. In this study its spreading and salinity change processes are explored using existing hydrographic data of the World Ocean Database 2009 and Argo floats. Spreading of NPTW is closely associated with the transports of the NEC, Mindanao Current (MC), and Kuroshio. Estimated for subsurface water with salinity S greater than 34.8 psu, the southward (northward) geostrophic transport of NPTW by the MC (Kuroshio) at 8°N (18°N) is about 4.4 (5.7) Sv (1 Sv = 10 6 m 3 s -1), which is not sensitive to reference level choice. Fields of salinity maximum, geostrophic current, sea level variation, and potential vorticity suggest that the equatorward spreading of NPTW to the tropics is primarily afforded by the MC, whereas its poleward spreading is achieved by both the Kuroshio transport along the coast and open-ocean mesoscale eddy fluxes in the northern PS. The NPTW also undergoes a prominent freshening in the PS. Lying beneath fresh surface water, salinity decreases quicker in the upper part of the NPTW, which gradually lowers the salinity maximum of NPTW to denser isopycnals. Salinity decrease is especially fast in the MC, with along-path decreasing rate reaching O (10 -7 psu s -1). Both diapycnal and isopycnal mixing effects are shown to be elevated in the MC owing to enhanced salinity gradient near the Mindanao Eddy. These results suggest intensive dispersion of thermal anomalies along the subtropical-to-tropical thermocline water pathway near the western boundary. © 2012 The Oceanographic Society of Japan and Springer.


Feng L.,University of Chinese Academy of Sciences | Chen Y.,Jilin University | Ren J.,University of Chinese Academy of Sciences | Qu X.,University of Chinese Academy of Sciences
Biomaterials | Year: 2011

Here we report an electrochemical sensor that can realize label-free cancer cell detection using the first clinical trial II used aptamer AS1411 and functionalized graphene. By taking advantages of AS1411 high binding affinity and specificity to the overexpressed nucleolin on the cancer cell surface, our developed electrochemical aptasensor can distinguish cancer cells and normal ones and detect as low as one thousand cells. With DNA hybridization technique, this E-DNA sensor can be regenerated and reusable for cancer cell detection. Our work gives a good example for label-free cancer cell detection based on aptamer and graphene-modified electrode. © 2011 Elsevier Ltd.


Wang W.,Jilin University | Wang W.,University of Chinese Academy of Sciences | Ma D.,University of Chinese Academy of Sciences
Applied Physics Letters | Year: 2010

An organic thin-film transistor memory, based on the pentacene semiconductor/nanoparticle-Al floating-gate/Al2O3 tunneling layer, is demonstrated by a simple fabrication process. The floating-gate transistor exhibits significant hysteresis behaviors in current-voltage characteristics and these hysteresis loops size depends on the gate voltage sweeping range. The memory windows of 32.5, 50, and 67.5 V and the memory ratio of 13, 32, and 70 can be obtained by the writing/erasing pulse of ±40 V, ±50 V, and ±60 V, respectively. The charge storage mechanism is discussed well via holes inject or eject the floated gate by F-N tunneling. © 2010 American Institute of Physics.


Nie X.,Dalian National Laboratory for Clean Energy | Nie X.,University of Chinese Academy of Sciences | Qian H.,Carnegie Mellon University | Ge Q.,Dalian National Laboratory for Clean Energy | And 2 more authors.
ACS Nano | Year: 2012

In this work, we explore the catalytic application of atomically monodisperse, thiolate-protected Au 25(SR) 18 (where R = CH 2CH 2Ph) nanoclusters supported on oxides for CO oxidation. The solution phase nanoclusters were directly deposited onto various oxide supports (including TiO 2, CeO 2, and Fe 2O 3), and the as-prepared catalysts were evaluated for the CO oxidation reaction in a fixed bed reactor. The supports exhibited a strong effect, and the Au 25(SR) 18/CeO 2 catalyst was found to be much more active than the others. Interestingly, O 2 pretreatment of the catalyst at 150 °C for 1.5 h significantly enhanced the catalytic activity. Since this pretreatment temperature is well below the thiolate desorption temperature (∼200 °C), the thiolate ligands should remain on the Au 25 cluster surface, indicating that the CO oxidation reaction is catalyzed by intact Au 25(SR) 18/CeO 2. We further found that increasing the O 2 pretreatment temperature to 250 °C (above the thiolate desorption temperature) did not lead to any further increase in activity at all reaction temperatures from room temperature to 100 °C. These results are in striking contrast with the common thought that surface thiolates must be removed-as is often done in the literature work-before the catalyst can exert high catalytic activity. The 150 °C O 2-pretreated Au 25(SR) 18/CeO 2 catalyst offers ∼94% CO conversion at 80 °C and ∼100% conversion at 100 °C. The effect of water vapor on the catalytic performance is also investigated. Our results imply that the perimeter sites of the interface of Au 25(SR) 18/CeO 2 should be the active centers. The intact structure of the Au 25(SR) 18 catalyst in the CO oxidation process allows one to gain mechanistic insight into the catalytic reaction. © 2012 American Chemical Society.


Gong P.,Tsinghua University | Gong P.,University of California at Berkeley | Liang S.,Ohio State University | Carlton E.J.,University of California at Berkeley | And 4 more authors.
The Lancet | Year: 2012

China has seen the largest human migration in history, and the country's rapid urbanisation has important consequences for public health. A provincial analysis of its urbanisation trends shows shifting and accelerating rural-to-urban migration across the country and accompanying rapid increases in city size and population. The growing disease burden in urban areas attributable to nutrition and lifestyle choices is a major public health challenge, as are troubling disparities in health-care access, vaccination coverage, and accidents and injuries in China's rural-to-urban migrant population. Urban environmental quality, including air and water pollution, contributes to disease both in urban and in rural areas, and traffic-related accidents pose a major public health threat as the country becomes increasingly motorised. To address the health challenges and maximise the benefits that accompany this rapid urbanisation, innovative health policies focused on the needs of migrants and research that could close knowledge gaps on urban population exposures are needed. © 2012 Elsevier Ltd.


Xiao X.,University of Chinese Academy of Sciences | Liu X.,University of Chinese Academy of Sciences | Zhao H.,University of Chinese Academy of Sciences | Chen D.,China Institute of Atomic Energy | And 4 more authors.
Advanced Materials | Year: 2012

Co3O4 with three different crystal plane structures - cubes bounded by {001}planes, truncated octahedra enclosed by {111} and {001} planes, and octahedra with exposed {111}planes - is synthesized using a very simple one-step hydrothermal method. The three kinds of Co3O 4 exhibit significantly different electrochemical performances and the effect of different exposed crystal planes on the electrochemical performance of Co3O4 is comprehensively studied. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhou Z.-J.,CAS Qingdao Institute of Oceanology | Zhou Z.-J.,University of Chinese Academy of Sciences | Sun L.,CAS Qingdao Institute of Oceanology
Developmental and Comparative Immunology | Year: 2015

Many C-type lectins (CTLs) have been identified in teleost, however, the in vivo function of fish CTLs is essentially unknown. In this study, we examined the function of a CTL (CsCTL1) from tongue sole. CsCTL1 possesses the conserved EPN motif required for mannose binding in mammals but unknown in function in fish. Recombinant CsCTL1 (rCsCTL1), but not the mutant rCsCTL1M bearing substitutions at EPN, interacted with and agglutinated a limited range of bacteria. The agglutinating ability of rCsCTL1 was abolished in the absence of calcium or presence of mannose. Binding of rCsCTL1 to bacteria promoted phagocytosis and antimicrobial activity of head kidney monocytes. Fish administered with rCsCTL1 exhibited enhanced resistance against bacterial and viral infections. These results provide the first evidence that the EPN site is essential to a fish CTL and that, in addition to antibacterial properties, a fish CTL promotes the immune defense against viral infection as well. © 2015 Elsevier Ltd.


Ding C.,Dalian National Laboratory for Clean Energy | Ding C.,University of Chinese Academy of Sciences | Zhang H.,Dalian National Laboratory for Clean Energy | Li X.,Dalian National Laboratory for Clean Energy | And 2 more authors.
Journal of Physical Chemistry Letters | Year: 2013

The vanadium flow battery (VFB) as one kind of energy storage technique that has enormous impact on the stabilization and smooth output of renewable energy. Key materials like membranes, electrode, and electrolytes will finally determine the performance of VFBs. In this Perspective, we report on the current understanding of VFBs from materials to stacks, describing the factors that affect materials' performance from microstructures to the mechanism and new materials development. Moreover, new models for VFB stacks as well as structural design will be summarized as well. Finally, the challenges, the overall cost evaluation, and future research directions will be briefly proposed. © 2013 American Chemical Society.


Yu J.,Clemson University | Wu C.,Clemson University | Wu C.,Jilin University | Tian Z.,Clemson University | And 2 more authors.
Nano Letters | Year: 2012

The motion of individual charge carriers in organic nanostructures was tracked by fluorescence microscopy. A twinkling effect is observed in fluorescence microscopy of single conjugated polymer nanoparticles, that is, small displacements in the fluorescence spot of single nanoparticles of the conjugated polymer PFBT are observed over time. There is evidence that superquenching by the charge carrier induces a dark spot in the nanoparticle, which moves with the carrier, resulting in the observed displacements in the fluorescence. Zero-field mobilities of individual charge carriers consistent with highly trapped polarons were obtained from tracking experiments. © 2012 American Chemical Society.


Wang Y.-T.,University of Chinese Academy of Sciences | Piao Y.-S.,University of Chinese Academy of Sciences | Piao Y.-S.,CAS Institute of Theoretical Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

The power suppression on large scale in the CMB TT-mode power spectrum might imply the occurrence of a pre-inflationary bounce. We calculate the circularly polarized gravitational wave, leaded by the gravitational Chern-Simons term universally appearing in particle physics and string theory, in the inflation model with the pre-inflationary bounce. The circularly polarized gravitational wave will induce TB- and EB-mode correlations at CMB last scatting surface. We find that if the pre-inflationary bounce actually occurs, the TB- and EB-mode correlations on large scale will be enhanced, while the BB-mode correlation on corresponding scales is suppressed. © 2014 The Authors.


Liu Y.,CAS Changchun Institute of Applied Chemistry | Liu Y.,University of Chinese Academy of Sciences | Ai K.,CAS Changchun Institute of Applied Chemistry | Liu J.,Jilin University | And 3 more authors.
Advanced Materials | Year: 2013

A new generation of photothermal therapeutic agents based on biopolymer dopamine-melanin colloidal nanospheres is described. Benefitting from their naturally wide distribution in humans, dopamine-melanin colloidal nanospheres exhibit robust biocompatibility and biodegradability, and provide up to 40% photothermal conversion efficiency. After administration, they can efficiently damage tumors at low power density and short irradiation time without damaging healthy tissues. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Bai D.,CAS Institute of Theoretical Physics | Bai D.,University of Chinese Academy of Sciences | Cui J.-W.,Huazhong University of Science and Technology | Wu Y.-L.,CAS Institute of Theoretical Physics | Wu Y.-L.,University of Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

Based on two postulations that (i) the Higgs boson has a large bare mass mH≫mh≃125GeV at the characteristic energy scale Mc which defines the Standard Model (SM) in the ultraviolet region, and (ii) quadratic contributions of Feynman loop diagrams in quantum field theories are physically meaningful, we show that the SM electroweak symmetry breaking is induced by the quadratic contributions from loop effects. As the quadratic running of Higgs mass parameter leads to an additive renormalization, which distinguishes from the logarithmic running with a multiplicative renormalization, the symmetry breaking occurs once the sliding energy scale μ moves from Mc down to a transition scale μ=ΛEW at which the additive renormalized Higgs mass parameter mH2(Mc/μ) gets to change the sign. With the input of current experimental data, this symmetry breaking energy scale is found to be ΛEW≃760GeV, which provides another basic energy scale for the SM besides Mc. Studying such a symmetry breaking mechanism could play an important role in understanding both the hierarchy problem and naturalness problem. It also provides a possible way to explore the experimental implications of the quadratic contributions as ΛEW lies within the probing reach of the LHC and the future Great Collider. © 2015 The Authors.


Liu Z.,CAS Changchun Institute of Applied Chemistry | Liu Z.,University of Chinese Academy of Sciences | Pu F.,CAS Changchun Institute of Applied Chemistry | Huang S.,Jilin University | And 3 more authors.
Biomaterials | Year: 2013

Due to their unique electric, magnetic, and optical properties, engineered nanostructures have been applied to provide diagnostic, therapeutic, as well as prognostic information about the status of disease. In this study, we report a multifunctional nanoprobe based on PEGylated Gd2O3:Yb3+, Er3+ nanorods (denoted as PEG-UCNPs) for in vivo up-conversion luminescence (UCL), T1-enhanced magnetic resonance (MR), and X-ray computed tomography (CT) multi-modality imaging. A facile and large-scale hydrothermal system combining the merits of an in situ thermal decomposition method and a surface-modified approach is introduced to construct high-quality PEG-UCNPs. By grafting PEG molecules on the surface of PEG-UCNPs, the nanostructures possess excellent stability against in vivo environment and hold long blood circulation time. Cell-cytotoxicity assay, hemolyticity, as well as post-injection histology, hematology, and inflammation analysis further demonstrate their non-cytotoxic character and indicate further in vivo application. In detail, the capability of PEG-UCNPs as high-performance contrast agents for UCL/MR/CT imaging is evaluated successfully through small-animal experiments. Additionally, pharmacokinetics, biodistribution, and clearance route are studied after intravenous injection in a mouse model, reflecting their overall safety. © 2012 Elsevier Ltd.


Ju J.,CAS Beijing National Laboratory for Molecular | Ju J.,University of Chinese Academy of Sciences | Xiao K.,CAS Beijing National Laboratory for Molecular | Xiao K.,University of Chinese Academy of Sciences | And 3 more authors.
Advanced Materials | Year: 2013

Inspired by the efficient fog collection on cactus spines, conical copper wires with gradient wettability are fabricated through gradient electrochemical corrosion and subsequent gradient chemical modification. These dual-gradient copper wires' fog-collection ability is demonstrated to be higher than that of conical copper wires with pure hydrophobic surfaces or pure hydrophilic surfaces, and the underlying mechanism is also analyzed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Duan J.,CAS Shanghai Institutes for Biological Sciences | Duan J.,University of Chinese Academy of Sciences | Cai W.,CAS Shanghai Institutes for Biological Sciences
PLoS ONE | Year: 2012

Late embryogenesis abundant (LEA) proteins are involved in tolerance to drought, cold and high salinity in many different organisms. In this report, a LEA protein producing full-length gene OsLEA3-2 was identified in rice (Oryza sativa) using the Rapid Amplification of cDNA Ends (RACE) method. OsLEA3-2 was found to be only expressed in the embryo and can be induced by abiotic stresses. The coding protein localizes to the nucleus and overexpression of OsLEA3-2 in yeast improved growth performance compared with control under salt- and osmotic-stress conditions. OsLEA3-2 was also inserted into pHB vector and overexpressed in Arabidopsis and rice. The transgenic Arabidopsis seedlings showed better growth on MS media supplemented with 150 mM mannitol or 100 mM NaCl as compared with wild type plants. The transgenic rice also showed significantly stronger growth performance than control under salinity or osmotic stress conditions and were able to recover after 20 days of drought stress. In vitro analysis showed that OsLEA3-2 was able to protect LDH from aggregation on freezing and inactivation on desiccation. These results indicated that OsLEA3-2 plays an important role in tolerance to abiotic stresses. © 2012 Duan, Cai.


Shao X.H.,CAS Shenyang Institute of Metal Research | Shao X.H.,University of Chinese Academy of Sciences | Yang Z.Q.,CAS Shenyang Institute of Metal Research | Ma X.L.,CAS Shenyang Institute of Metal Research
Acta Materialia | Year: 2010

The deformation behavior and corresponding microstructure evolution of a Mg97Zn1Y2 (at.%) alloy with a long period stacking ordered (LPSO) structure subjected to hot compression were investigated. The peak stress at 573 K was about 190 MPa, and no macroscopic fracture took place up to a strain of about 60%. The mechanisms responsible for the mechanical performance of the Mg97Zn1Y2 (at.%) alloy are discussed based on microstructural investigations using various electron microscopy techniques. The high strength at elevated temperature could be attributed to synergetic strengthening refinement of the LPSO via kinking and a limited fraction of dynamical recrystallization. Microcracks nucleated at the interfaces in the sandwich structure composed of LPSO and nanometer thick Mg slices could weaken the alloy at late stages of deformation, but their propagation could be limited within the individual kink band where the microcracks nucleated, which could ensure the capability of the alloy to resist premature or catastrophic fracture. Furthermore, lack of deformation twins in Mg grains effectively reduced the potential nucleation sites for cracks, which should be another reason for the good ductility of the alloy. These findings may provide or evoke insights into methods for optimizing the mechanical properties of Mg alloys. © 2010 Acta Materialia Inc.


Liang Z.-L.,CAS Institute of Theoretical Physics | Liang Z.-L.,University of Chinese Academy of Sciences | Wu Y.-L.,CAS Institute of Theoretical Physics | Wu Y.-L.,University of Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We investigate the implication of different elastic spin-dependent (SD) operators on both the direct and indirect detections of the weakly interacting massive particle (WIMP). Six representative building blocks of SD operators, together with their counterparts with a massless mediator, are considered to interpret the direct detection experiments (Xenon100, SIMPLE, and COUPP) in a comprehensive way. We also study the solar capture and annihilation of WIMPs with these effective SD operators and place the constraints on the relevant annihilation rate from neutrino detection experiments Super-Kamionkande and IceCube. Upper limits on the WIMP-nucleon couplings drawn from direct detections are also projected to the annihilation rate for contrast and complementarity. We find that the efficiency of these mentioned detection strategies depends specifically on the six SD operators, while the neutrino-based detections are more effective in exploring the parameter space for the massless mediator scenario. © 2014 American Physical Society.


Hong G.-J.,CAS Shanghai Institutes for Biological Sciences | Hong G.-J.,University of Chinese Academy of Sciences | Xue X.-Y.,CAS Shanghai Institutes for Biological Sciences | Xue X.-Y.,University of Chinese Academy of Sciences | And 4 more authors.
Plant Cell | Year: 2012

Arabidopsis thaliana flowers emit volatile terpenes, which may function in plant-insect interactions. Here, we report that Arabidopsis MYC2, a basic helix-loop-helix transcription factor, directly binds to promoters of the sesquiterpene synthase genes TPS21 and TPS11 and activates their expression. Expression of TPS21 and TPS11 can be induced by the phytohormones gibberellin (GA) and jasmonate (JA), and both inductions require MYC2. The induction of TPS21 and TPS11 results in increased emission of sesquiterpene, especially (E)-β-caryophyllene. DELLAs, the GA signaling repressors, negatively affect sesquiterpene biosynthesis, as the sesquiterpene synthase genes were repressed in plants overaccumulating REPRESSOR OF GA1-3 (RGA), one of the Arabidopsis DELLAs, and upregulated in a penta DELLA-deficient mutant. Yeast two-hybrid and coimmunoprecipitation assays demonstrated that DELLAs, represented by RGA, directly interact with MYC2. In yeast cells, the N terminus of MYC2 was responsible for binding to RGA. MYC2 has been proposed as a major mediator of JA signaling and crosstalk with abscisic acid, ethylene, and light signaling pathways. Our results demonstrate that MYC2 is also connected to GA signaling in regulating a subset of genes. In Arabidopsis inflorescences, it integrates both GA and JA signals into transcriptional regulation of sesquiterpene synthase genes and promotes sesquiterpene production. © 2012 American Society of Plant Biologists. All rights reserved.


Wei W.,University of Chinese Academy of Sciences | Ji J.-X.,CAS Chengdu Institute of Biology
Angewandte Chemie - International Edition | Year: 2011

Direct access: The title reaction has been developed under mild reaction conditions (see scheme; DMSO=dimethyl sulfoxide). This reaction can be effectively scaled up and offers not only a green and attractive approach to β-ketophosphonates, but also a useful example of direct incorporation of an oxygen atom from dioxygen into organic frameworks. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Cheng C.,CAS Institute of Theoretical Physics | Cheng C.,University of Chinese Academy of Sciences | Huang Q.-G.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

Recently released Planck data imply a smaller Hubble constant H0 than that from the Hubble Space Telescope project (HST) and a larger percentage of the matter components Ωm compared to the Supernova Legacy Survey (SNLS) in the Λ cold dark matter (CDM) model. In this paper we found that even though the tension on H0 between Planck and HST can be relaxed if the dark radiation is introduced [ΔNeff=0.536-0.224+0.229 at 68% CL from the data sets of Planck+WMAP polarization (WP)+baryon acoustic oscillation (BAO)+the combination of supernova Union2.1 compilation of 580 Supernovae (Union2.1)+HST], Ωm from Planck is still not nicely compatible with that from SNLS. The tensions between Planck and other astrophysical data sets can be significantly relaxed in the wCDM model, and the combination of these data sets prefers a phantomlike dark energy at more than 95% CL: w=-1.15±0.07 and w=-1.16±0.06 at 68% CL from Planck+WP+BAO+Union2.1+HST and Planck+WP+BAO+SNLS+HST, respectively. From the statistical point of view, there is no evidence for a time-evolving equation of state (Δχ2=-0.3 compared to a constant equation of state for the combination of Planck+WP+BAO+SNLS+HST). © 2014 American Physical Society.


Feng K.,University of Chinese Academy of Sciences | Qiu T.,Central China Normal University | Qiu T.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

In our previous paper [K. Feng, T. Qiu, and Y.-S. Piao, Phys. Lett. B 729, 99 (2014)], we have shown a curvaton model where the curvaton has a nonminimal derivative coupling to gravity. Such a coupling could cause scale invariance of the perturbations for a wide range of constant values of the equation of state of the cosmic background at the early time. In this paper, we continue our study by fully analyzing its perturbations up to the third order. Apart from the usual 2-point correlation function that have already been calculated in Feng, Qiu, and Piao [Phys. Lett. B 729, 99 (2014)], we also take into account the 3-point correlation functions, including the pure scalar part, the pure tensor part, and the cross-correlations between scalar and tensor perturbation modes. We find that for the pure scalar part, the 3-point correlation functions can generate non-Gaussianities that fit the PLANCK data very well. For the pure tensor and mixed parts, the shape functions have peaks at squeezed and equilateral limits, respectively, responsible for sizable fNLsqz and fNLeql, which could be tested by the future observational data. © 2014 American Physical Society.


Sun M.,CAS Research Center for Eco Environmental Sciences | Sun M.,University of Chinese Academy of Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Liu Y.,Tsinghua University | And 2 more authors.
Nanoscale | Year: 2015

The development of low cost, durable and efficient nanocatalysts to substitute expensive and rare noble metals (e.g. Pt, Au and Pd) in overcoming the sluggish kinetic process of the oxygen reduction reaction (ORR) is essential to satisfy the demand for sustainable energy conversion and storage in the future. Graphene based transition metal oxide nanocomposites have extensively been proven to be a type of promising highly efficient and economic nanocatalyst for optimizing the ORR to solve the world-wide energy crisis. Synthesized nanocomposites exhibit synergetic advantages and avoid the respective disadvantages. In this feature article, we concentrate on the recent leading works of different categories of introduced transition metal oxides on graphene: from the commonly-used classes (FeOx, MnOx, and CoOx) to some rare and heat-studied issues (TiOx, NiCoOx and Co-MnOx). Moreover, the morphologies of the supported oxides on graphene with various dimensional nanostructures, such as one dimensional nanocrystals, two dimensional nanosheets/nanoplates and some special multidimensional frameworks are further reviewed. The strategies used to synthesize and characterize these well-designed nanocomposites and their superior properties for the ORR compared to the traditional catalysts are carefully summarized. This work aims to highlight the meaning of the multiphase establishment of graphene-based transition metal oxide nanocomposites and its structural-dependent ORR performance and mechanisms. © 2015 The Royal Society of Chemistry.


Zhou K.,University of Chinese Academy of Sciences | Li Y.,Tsinghua University
Angewandte Chemie - International Edition | Year: 2012

Using bottom-up chemistry techniques, the composition, size, and shape in particular can now be controlled uniformly for each and every nanocrystal (NC). Research into shape-controlled NCs have shown that the catalytic properties of a material are sensitive not only to the size but also to the shape of the NCs as a consequence of well-defined facets. These findings are of great importance for modern heterogeneous catalysis research. First, a rational synthesis of catalysts might be achieved, since desired activity and selectivity would be acquired by simply tuning the shape, that is, the exposed crystal facets, of a NC catalyst. Second, shape-controlled NCs are relatively simple systems, in contrast to traditional complex solids, suggesting that they may serve as novel model catalysts to bridge the gap between model surfaces and real catalysts. Shape-controlled nanocrystals (NCs) are a new frontier in heterogeneous catalysis. Research into these NCs has shown that the catalytic properties of a material are sensitive not only to the size but also to the shape of the NCs owing to well-defined facets. Shape-controlled NCs may serve to bridge the gap between model surfaces and real catalysts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Mi S.-B.,CAS Shenyang Institute of Metal Research | Mi S.-B.,Xi'an Jiaotong University | Jin Q.-Q.,CAS Shenyang Institute of Metal Research | Jin Q.-Q.,University of Chinese Academy of Sciences
Scripta Materialia | Year: 2013

New types of long-period stacking ordered (LPSO) structures were observed in Mg-Co-Y as-cast alloys by means of transmission electron microscopy and scanning transmission electron microscopy. The new types of LPSO are characterized by a structural unit consisting of either three stacking layers AB′C, or four stacking layers AB′C′A, distributed periodically along the normal of the closely packed planes in the alloy matrix. In the structural units, the B′ and C′ layers are identified as Co/Y-enriched.


Zhang J.,CAS Institute of Genetics and Developmental Biology | Zhang J.,University of Chinese Academy of Sciences | Pawlowski W.P.,Cornell University | Han F.,CAS Institute of Genetics and Developmental Biology
Plant Cell | Year: 2013

Pairing of homologous chromosomes in meiosis is critical for their segregation to daughter cells. In most eukaryotes, clustering of telomeres precedes and facilitates chromosome pairing. In several species, centromeres also form pairwise associations, known as coupling, before the onset of pairing. We found that, in maize (Zea mays), centromere association begins at the leptotene stage and occurs earlier than the formation of the telomere bouquet. We established that centromere pairing requires centromere activity and the sole presence of centromeric repeats is not sufficient for pairing. In several species, homologs of the ZIP1 protein, which forms the central element of the synaptonemal complex in budding yeast (Saccharomyces cerevisiae), play essential roles in centromere coupling. However, we found that the maize ZIP1 homolog ZYP1 installs in the centromeric regions of chromosomes after centromeres form associations. Instead, we found that maize STRUCTURAL MAINTENANCE OF CHROMOSOMES6 homolog forms a central element of the synaptonemal complex, which is required for centromere associations. These data shed light on the poorly understood mechanism of centromere interactions and suggest that this mechanism may vary somewhat in different species. © 2013 American Society of Plant Biologists. All rights reserved.


Wang H.,University of Chinese Academy of Sciences | Qiu T.,National Taiwan University | Qiu T.,CAS Institute of High Energy Physics | Piao Y.-S.,University of Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

In this Letter, we study a curvaton model where the curvaton is acted by Galileon field. We calculate the power spectrum of fluctuation of G-Curvaton during inflation and discuss how it converts to the curvature perturbation after the end of inflation. We estimate the bispectrum of curvature perturbation induced, and show the dependence of non-Gaussianity on the parameters of model. It is found that our model can have sizable local and equilateral non-Gaussianities to up to O(102), which is illustrated by an explicit example. © 2011 Elsevier B.V.


Man W.,CAS Institute of Atmospheric Physics | Man W.,University of Chinese Academy of Sciences | Zhou T.,CAS Institute of Atmospheric Physics | Jungclaus J.H.,Max Planck Institute for Meteorology
Journal of Climate | Year: 2012

The decadal-centennial variations of East Asian summer monsoon (EASM) and the associated rainfall change during the past millennium are simulated using the earth system model developed at the Max Planck Institute for Meteorology. The model was driven by up-to-date reconstructions of external forcing including the recent low-amplitude estimates of solar variations. Analysis of the simulations indicates that the EASM is generally strong during the Medieval Warm Period (MWP; A.D. 1000-1100) and weak during the Little Ice Age (LIA; A.D. 1600-1700). The monsoon rainband exhibits a meridional tripolar pattern during both epochs. Excessive (deficient) precipitation is found over northern China (35°-42°N, 100°-120°E) but deficient(excessive) precipitation is seen along the Yangtze River valley (27°-34°N, 100°-120°E) during the MWP(LIA). Both similarities and disparities of the rainfall pattern between the model results herein and the proxy data have been compared, and reconstructions from Chinese historical documents and some geological evidence support the results. The changes of the EASM circulation including the subtropical westerly jet stream in the upper troposphere and the western Pacific subtropical high (WPSH) in the middle and lower troposphere are consistent with the meridional shift of the monsoon rain belt during both epochs. The meridional monsoon circulation changes are accompanied with anomalous southerly (northerly) winds between 20° and 50°N duringthe MWP (LIA). The land-sea thermal contrast change caused by the effective radiative forcing leads to the MWP and LIA monsoon changes. The "warmer land-colder ocean" anomaly pattern during the MWP favors a stronger monsoon, while the "colder land-warmer ocean" anomaly pattern during the LIA favors a weaker monsoon. © 2012 American Meteorological Society.


Zhang J.-C.,CAS Chengdu Institute of Biology | Zhang J.-C.,University of Chinese Academy of Sciences | Ji J.-X.,CAS Chengdu Institute of Biology
ACS Catalysis | Year: 2011

A simple and efficient method for the synthesis of polysubstituted 1,2-dihydroquinolines has been developed via an indium(III)-catalyzed tandem reaction of α-ketoesters with primary or secondary aromatic amines. With respect to the reactions of pyruvates with amines, indium triflate (1 mol %) demonstrated superior catalytic activity and efficiency compared with previously reported AuCl 3/AgSbF 6 (5 mol %/15 mol %) cocatalyst. The reactions of α-alkyl substituted ketoesters and arylamines, which could not be effectively accomplished by the previous AuCl 3/AgSbF 6 and HNO 3 catalytic systems proceeded smoothly in the presence of 10 mol % In(OTf) 3 to afford the desired products in moderate to good yields (43%-91%). © 2011 American Chemical Society.


Huang T.,CAS Institute of Geology and Geophysics | Huang T.,University of Chinese Academy of Sciences | Pang Z.,CAS Institute of Geology and Geophysics
Journal of Hydrology | Year: 2010

The Lower Tarim River in NW China is under severe ecosystem degradation due to stopped stream flow and diminished groundwater recharge. Since year 2000, eight water diversions from the upper stream and from the neighboring Kaidu-Kongque River have been implemented to alleviate the ecosystem disaster. In order to assess the effectiveness of the water diversion project and to identify proper tracers of groundwater dynamics, we sampled the riparian groundwater system in 2007 and 2008 along the 350km-long river channel through the 40 monitoring wells situated along nine transects perpendicular to the river and three soil profiles. Measurements on the samples have included environmental isotopes (18O, 2H, 3H) and water chemistry. The results show that remarkable changes have been induced by the water diversions. The observed response of riparian groundwater system includes general decrease in total dissolved solid (TDS) and rise of water table. Scope with greater than 1m rise in water table is within ∼700m from the riverbank in the upper segments and ∼300m in the lower ones. Greater rise of water table occurs near the river bank. Tritium data show that the extent of modern recharge (since 1960s), including that from the diverted water, is limited to 600m from the riverbank at the upper segments and 200m at the lower ones. Stable isotopes show that groundwaters, regardless of modern or pre-modern, are enriched in heavy isotopes and are plotted in parallel to the meteoric water line in the δ-δ plot, attributed to evaporation during recharge. Groundwater is generally of Na-Mg-Cl-SO4 type and is formed by dissolution of minerals, such as halite, sulfate, and carbonates, based on component correlation matrices analysis. The salinity of groundwater is mainly affected by that of the diverted water and of the local antecedent groundwater, salts in the unsaturated zone, evapotranspiration during recharge. As the zone of smaller groundwater depth (less than 5m) suitable for the most existing Populus euphratica and Tamarix ramosissima, the main species targeted by the rescue effort, restricts to 200m from the riverbank, and narrows down towards downstream, long-term stability of the ecosystem cannot be achieved by the current water diversion scheme and regulating/saving water in source-streams and the Upper/Middle Tarim River is crucial for continuing water diversion. © 2010 Elsevier B.V.


Du F.-T.,CAS Chengdu Institute of Biology | Du F.-T.,University of Chinese Academy of Sciences | Ji J.-X.,CAS Chengdu Institute of Biology
Chemical Science | Year: 2012

A novel and efficient copper-catalyzed direct oxidative synthesis of α-ketoamides from aryl methyl ketones, amines, and molecular oxygen has been developed under mild and neat conditions. 18O labeling experiments revealed that both oxygen atoms of the α-ketoamides derived from molecular oxygen. © 2012 The Royal Society of Chemistry.


Wang Y.,CAS Institute of Geology and Geophysics | Wang Y.,University of Chinese Academy of Sciences | Lin W.,CAS Institute of Geology and Geophysics | Pana Y.,CAS Institute of Geology and Geophysics
Applied and Environmental Microbiology | Year: 2013

Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. © 2013, American Society for Microbiology.


Ma S.,CAS Shenyang Institute of Metal Research | Ma S.,University of Chinese Academy of Sciences | Wang S.,CAS Shenyang Institute of Metal Research
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We identified the states of intrinsic point defects underlying the self-diffusion in Si and clarified the change of dominant diffusion mechanism responsible for the self-diffusion over a wide temperature range using ab initio method. We presented a reliable self-diffusion model that the mechanisms of vacancies and self-interstitials dominate below and above 1220 K, respectively. Our calculations provided a clear picture of Si self-diffusion at lower and higher temperature ascribed to single point defects rather than extended defects. The calculations also provided valuable information on the energy levels and the thermal equilibrium concentrations of point defects, which are highly controversial in experimental reports due to detection limits. © 2010 The American Physical Society.


Wu J.,CAS Qingdao Institute of Oceanology | Wu J.,University of Chinese Academy of Sciences | Zhang D.,CAS Qingdao Institute of Oceanology | Wang Y.,CAS Qingdao Institute of Oceanology | Hou B.,CAS Qingdao Institute of Oceanology
Journal of Power Sources | Year: 2013

Nitrogen-doped graphene (NG) materials have been prepared by hydrothermal reaction of graphite oxide (GO) with urea, and their electrocatalytic properties towards oxygen reduction reaction in 0.1 M KOH are investigated. The introduction of urea leads to successful nitrogen insertion in the form of pyridinic, pyrrolic, and graphitic bonding configurations with enhanced reduction of GO, and an increase in the mass ratio between urea and GO gives higher nitrogen contents, which is accompanied by more defects in microstructure. Reduction of O2 to OH- at lower overpotentials is favored by the incorporation of nitrogen, and the activity of NG is closely associated with nitrogen contents and microstructure. NG materials with ca. 7% nitrogen contents and moderate defect densities prepared from mass ratios of 1:200 and 1:300 (GO/urea) show the best performance. © 2012 Elsevier B.V. All rights reserved.


Wang Y.,CAS Qingdao Institute of Oceanology | Wan Y.,CAS Qingdao Institute of Oceanology | Wan Y.,University of Chinese Academy of Sciences | Zhang D.,CAS Qingdao Institute of Oceanology
Electrochemistry Communications | Year: 2010

This paper describes the electrochemical properties of reduced graphene sheets (RGSs) for the electrocatalytic properties towards the hydrazine oxidation in alkaline media. The RGSs have been produced in high yield by a soft chemistry route involving graphite oxidation, ultrasonic exfoliation, and chemical reduction. The RGSs possess excellent electrocatalytic activity towards the hydrazine oxidation. In our opinion, RGSs are a potential electrode material for direct hydrazine fuel cells and electrochemical sensors for hydrazine detection. © 2009 Elsevier B.V. All rights reserved.


Lin C.,University of Chinese Academy of Sciences | Yang K.,CAS Institute of Tibetan Plateau Research | Qin J.,CAS Institute of Tibetan Plateau Research | Fu R.,University of Texas at Austin | Fu R.,Tsinghua University
Journal of Climate | Year: 2013

Previous studies indicated that surface wind speed over China declined during past decades, and several explanations exist in the literature. This study presents long-term (1960-2009) changes of both surface and upper-air wind speeds over China and addresses observed evidence to interpret these changes. It is found that surface wind over China underwent a three-phase change over the past 50 yr: (i) it step changed to a strong wind level at the end of the 1960s, (ii) it declined until the beginning of the 2000s, and (iii) it seemed to be steady and even recovering during the very recent years. The variability of surface wind speed is greater at higher elevations and less at lower elevations. In particular, surface wind speed over the elevated Tibetan Plateau has changed more significantly. Changes in upper-air wind speed observed from rawinsonde are similar to surface wind changes. The NCEP-NCAR reanalysis indicates that wind speed changes correspond to changes in geopotential height gradient at 500 hPa. The latter are further correlated with the changes of latitudinal surface temperature gradient, with a correlation coefficient of 0.88 for the past 50 yr over China. This strongly suggests that the spatial gradient of surface global warming or cooling may significantly change surface wind speed at a regional scale through atmospheric thermal adaption. The recovery of wind speed since the beginning of the 2000s over the Tibetan Plateau might be a precursor of the reversal of wind speed trends over China, as wind over high elevations can respond more rapidly to the warming gradient and atmospheric circulation adjustment. © 2013 American Meteorological Society.


Zhou L.-J.,CAS Fujian Institute of Research on the Structure of Matter | Zhou L.-J.,University of Chinese Academy of Sciences | Hou Z.F.,Xiamen University | Wu L.-M.,CAS Fujian Institute of Research on the Structure of Matter
Journal of Physical Chemistry C | Year: 2012

To understand the effect of point defects on the Li adsorption on graphene, we have studied the adsorption and diffusion of lithium on graphene with divacancy and Stone-Wales defect using the first-principles calculations. Our results show that in the presence of divacancy Li adatom energetically prefers the hollow site above the center of an octagonal ring rather than the top sites of carbon atoms next to vacancy site. In the case of Stone-Wales defect, Li atom is energetically favorable to be adsorbed on the top site of carbon atom in a pentagonal ring shared with two hexagonal rings, and such adsorption results in a bucking of graphene sheet. For divacancy and Stone-Wales defects in graphene, their interactions with a Li adatom are attractive, suggesting that the presence of point defects would enhance the Li adsorption on graphene. The difference charge density and the Bader charge analysis both show that there is a significant charge transfer from Li adatom to it nearest neighbor carbon atoms. © 2012 American Chemical Society.


Liu K.,CAS Shanghai Institutes for Biological Sciences | Liu K.,University of Chinese Academy of Sciences | Yao H.,CAS Shanghai Institutes for Biological Sciences
European Journal of Neuroscience | Year: 2014

Both theoretical and experimental studies suggest that response properties in the visual system are shaped by signals in the natural environment. Recent studies showed that, in the primary visual cortex (V1), neurons preferring light decrements (OFF stimuli) outnumber those preferring light increments (ON stimuli). However, it is not clear whether the OFF-dominance in V1 neurons is related to the contrast statistics in natural images. By analysing the distribution of negative and positive contrasts in natural images at several spatial scales, we showed that optimal coding of the natural contrast signals would lead to a contrast-dependent OFF-dominant response, with a stronger degree of OFF-dominance at a higher contrast. Using bright and dark stimuli at various contrast levels to measure the receptive fields of neurons in cat V1, we found an increasing degree of OFF-dominance of the neuronal population as the contrast was increased. By modeling receptive fields exhibiting OFF- and ON-dominance, we found that contrast-dependent OFF-dominance facilitated the discrimination of stimuli with natural contrast distribution. Thus, by matching contrast-dependent OFF-dominance to the statistics of contrast distribution in natural images, V1 neurons may better discriminate contrast information in natural scenes. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.


Zheng W.-J.,CAS Qingdao Institute of Oceanology | Zheng W.-J.,University of Chinese Academy of Sciences | Sun L.,CAS Qingdao Institute of Oceanology
Fish and Shellfish Immunology | Year: 2011

Japanese flounder (Paralichthys olivaceus) is an important economic fish species cultured worldwide. In this report, we compared the potentials of ten housekeeping genes as quantitative real time RT-PCR (qRT-PCR) references for the study of gene expression in Japanese flounder under normal physiological conditions and during bacterial infection. For this purpose, the expression of the ten genes in eight flounder tissues (liver, spleen, kidney, heart, muscle, brain, gill, and intestine) was determined by qRT-PCR before and after bacterial infection. The expression levels of the housekeeping genes were then compared and evaluated with geNorm and NormFinder algorithms. The results showed that before bacterial infection, the tested genes exhibited tissue-specific expressions to various degrees, with β-actin and ubiquitin-conjugating enzyme being ranked as the most stable genes across tissue types. Following bacterial challenge, all the tested genes varied in expression levels in tissue-dependent manners and no cross-all-tissue type reference gene was identified among the examined panel of housekeeping genes; however, α-tubulin was recognized as the most stable gene in four (spleen, heart, muscle, and gill) of the eight examined tissues. These results indicate that for qRT-PCR analysis of gene expression in Japanese flounder as a function of bacterial infection, the choice of reference genes should be made according to tissue type. © 2010 Elsevier Ltd.


Kong Y.,CAS Institute of Geology and Geophysics | Kong Y.,University of Chinese Academy of Sciences | Pang Z.,CAS Institute of Geology and Geophysics
Journal of Hydrology | Year: 2012

The magnitude and variability of water system's response to climate change impacts have been assessed through a detailed analysis of discharge composition of two selected typical glacier rivers originated from Tianshan Mountains, Xinjiang Uygur Autonomous Region in West China, which is considered as the water tower of Central Asia. Here we demonstrate climate change in the last 60. years using meteorological data (1951-2009) in the region. Both of the temperature and precipitation show a remarkable rise before and after year 1990 and these changes are much more significant in North Xinjiang than it is in South Xinjiang. Response of water systems towards climate change is then assessed by comparing annual discharge change of Urumqi River (10.0%) in the North and Kumalak River (38.7%) in South Xinjiang. We found significant inconsistency of the climate change impact on water resources. Furthermore, we quantitatively determine the ratio of ice-melt water using isotope hydrograph separation as well as other conservative tracers. Results show that Urumqi River is recharged by less than 9% of ice-melt water, while Kumalak River contains more than 57% of ice-melt water in their discharges. The extent of glacier input to a water system governs its sensitivity towards climate change. The method has overwhelming potential for un-gauged watersheds and may offer ways of adaptation to climate change in terms of water resources management for flood control and sustainable agriculture. © 2012 Elsevier B.V.


Fu Z.,CAS Chengdu Institute of Biology | Fu Z.,University of Chinese Academy of Sciences | Shao H.,CAS Chengdu Institute of Biology
Ultrasonics Sonochemistry | Year: 2011

A solvent-free procedure for the synthesis of 3-substituted indole derivates from indoles and nitroalkenes under ultrasound irradiation is described. Control experiments disclosed besides mechanical effects, namely agitation, sonochemical effects are the main forces to drive the reaction. In the method, 2-chloroethanol was used to prepare a wide variety of 3-substituted indole derivates. This procedure only need equimolar amounts of reaction substrates and can be readily scaled up. © 2010 Elsevier B.V.


Dang W.,CAS Qingdao Institute of Oceanology | Dang W.,University of Chinese Academy of Sciences | Sun L.,CAS Qingdao Institute of Oceanology
Fish and Shellfish Immunology | Year: 2011

In recent years, quantitative real time reverse transcriptase-PCR (qRT-PCR) has been used frequently in the study of gene expression in turbot (Scophthalmus maximus) in relation to bacterial infection. However, no investigations on appropriate qRT-PCR reference genes have been documented. In this report, we determined the potential of eight housekeeping genes, i.e. β-actin (ACTB), ribosomal protein L17 (RPL17), α-tubulin (TUBA), elongation factor-1-α(EF1A), β-2-Microglobulin (B2M), RNA polymerase II subunit D (RPSD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and 18S ribosomal RNA (18S rRNA), as internal standards for qRT-PCR analysis of gene expression in turbot as a function of bacterial infection. For this purpose, the expression of the eight housekeeping genes in seven turbot tissues was determined by qRT-PCR before and after bacterial challenge, and the data were analyzed with the geNorm and NormFinder algorisms. The results showed that the expression of all the examined genes exhibited tissue-dependent variations both before and after bacterial challenge. Before bacterial challenge, geNorm and NormFinder identified RPSD as the gene that showed least tissue specific expression. At 12 h post-bacterial infection, geNorm ranked ACTB/GAPDH, 18S rRNA/ACTB, ACTB/GAPDH, 18S rRNA/ACTB, RPL17/TUBA, RPSD/GAPDH, and RPSD/B2M, respectively, as the most stably expressed genes in liver, spleen, kidney, gill, heart, muscle, and brain. Comparable ranking orders were produced by NormFinder. Similar results were obtained at 24 h post-bacterial infection. Taken together, these results indicate that RPSD is the most stable gene across tissue types under normal physiological conditions and that, during bacterial infection, ACTB might be used as an internal standard for the normalization of gene expression in immune relevant organs; however, no single gene or single pair of genes in the examined set of housekeeping genes can serve as a universal reference across all tissue types under the condition of bacterial infection. © 2011 Elsevier Ltd.


Sun Y.-Y.,CAS Qingdao Institute of Oceanology | Sun Y.-Y.,University of Chinese Academy of Sciences | Sun L.,CAS Qingdao Institute of Oceanology
Veterinary Microbiology | Year: 2015

For pathogenic bacteria, the ability to acquire iron is vital to survival in the host. In consequence, many genes involved in iron acquisition are associated with bacterial virulence. Pseudomonas fluorescens is a bacterial pathogen to a variety of farmed fish. However, the global regulatory function of iron in pathogenic P. fluorescens is essentially unknown. In this study, in order to identify proteins affected by iron condition at the expression level, we performed proteomic analysis to compare the global protein profiles of P. fluorescens strain TSS, a fish pathogen, cultured under iron-replete and iron-deplete conditions. Twenty-two differentially expressed proteins were identified, most of which were confirmed to be regulated by iron at the mRNA level. To investigate their potential involvement in virulence, the genes encoding four of the 22 proteins, i.e. HemO (heme oxygenase), PspB (serine protease), Sod (superoxide dismutase), and TfeR (TonB-dependent outermembrane ferric enterobactin receptor), were knocked out, and the pathogenicity of the mutants was examined in a model of turbot (. Scophthalmus maximus). The results showed that compared to the wild type, the hemO, pspB, and tfeR knockouts were significantly impaired in the ability to survive in host serum, to invade host tissues, and to cause host mortality. Immunization of turbot with recombinant TfeR (rTfeR) and PspB induced production of specific serum antibodies and significant protections against lethal TSS challenge. Further analysis showed that rTfeR antibodies recognized and bound to TSS, and that treatment of TSS with rTfeR antibodies significantly impaired the infectivity of TSS to fish cells. Taken together, these results indicate for the first time that in pathogenic P. fluorescens, iron affects the expression of a large number of proteins including those that are involved in host infection. © 2015 Elsevier B.V.


Chen B.,Dalian National Laboratory for Clean Energy | Chen B.,University of Chinese Academy of Sciences | Wang L.,Dalian National Laboratory for Clean Energy | Gao S.,Dalian National Laboratory for Clean Energy
ACS Catalysis | Year: 2015

Imines as valuable intermediates are widely applied in pharmaceutical syntheses and organic transformation. However, the traditional imine synthesis involves unstable aldehydes, dehydrating agents, and Lewis acid catalysts. The topic of this review is focused on three new approaches, namely, the cross-coupling of alcohols with amines, the self-coupling of primarily amines, and the oxidative dehydrogenation of secondary amines, utilizing much more readily available starting materials and green oxidant (O2/air) to furnish the imine products. The related catalysts are classified into metal, metal-free, photo-, and bioinspired catalysts. Particular emphasis is placed on the high-active, low-cost, and versatile catalysts; key factors that affect the catalytic activity and reaction mechanisms are also highlighted. © 2015 American Chemical Society.


Qian B.,CAS Qingdao Institute of Oceanology | Qian B.,University of Chinese Academy of Sciences | Hou B.,CAS Qingdao Institute of Oceanology | Zheng M.,CAS Qingdao Institute of Oceanology
Corrosion Science | Year: 2013

The inhibition effect of tannic acid on mild steel corrosion in seawater wet/dry cyclic conditions was studied by weight loss and electrochemical methods. Result of the polarisation curves shows that corrosion current density decreases from 47.85μAcm-2 to 6.67μAcm-2 after tannic acid is added; charge transfer resistance remains stable in the electrochemical impedance spectra. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared reflection are performed to study the corrosion inhibition. The inhibition effect of the compound is attributed to ferric tannate film formation on the steel surface, which is relatively stable during wet/dry cycles. © 2013 Elsevier Ltd.


Liu G.,University of Chinese Academy of Sciences | Zhang R.,CAS Beijing Institute of Genomics | Xu J.,University of Chinese Academy of Sciences | Wu C.-I.,Sun Yat Sen University | Lu X.,University of Chinese Academy of Sciences
Molecular biology and evolution | Year: 2015

MicroRNAs (miRNAs) mediate gene regulation posttranscriptionally through pairing of their seed (2-7 nt) to 3'-untranslated regions (3'-UTRs) or coding regions (coding sequences [CDSs]) of their target genes. CDS target sites generally show weaker repression effects than 3'-UTR sites. However, little is known about the conservation of the function, that is, repression effect, for these two groups of target sites. In addition, no systematic analysis of the evolutionary constraint on CDS sites exists to date. To address these questions, we performed RNA-sequencing to quantify the regulatory effect of miR-15a/miR-16 and miR-92a on their CDS and 3'-UTR targets in human and macaque cells. These miRs were knocked down transiently so the repression effect could be tracked immediately. Although on average CDS targets are less derepressed than 3'-UTR targets in both species, both the 3'-UTR targets and the CDS targets are functionally conserved. The evolutionary analysis of miRNA target sites shows that CDS sites are more conserved than nontarget control, albeit to a lesser extent than 3'-UTR sites. In conclusion, CDS target sites are functional, even though they are subject to less functional constraint than 3'-UTR target sites. © Crown copyright 2014.


Tang Q.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Zhang X.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Zhang X.,University of Chinese Academy of Sciences | Francis J.A.,Rutgers University
Nature Climate Change | Year: 2014

The past decade has seen an exceptional number of unprecedented summer extreme weather events in northern mid-latitudes, along with record declines in both summer Arctic sea ice and snow cover on high-latitude land. The underlying mechanisms that link the shrinking cryosphere with summer extreme weather, however, remain unclear. Here, we combine satellite observations of early summer snow cover and summer sea-ice extent with atmospheric reanalysis data to demonstrate associations between summer weather patterns in mid-latitudes and losses of snow and sea ice. Results suggest that the atmospheric circulation responds differently to changes in the ice and snow extents, with a stronger response to sea-ice loss, even though its reduction is half as large as that for the snow cover. Atmospheric changes associated with the combined snow/ice reductions reveal widespread upper-level height increases, weaker upper-level zonal winds at high latitudes, a more amplified upper-level pattern, and a general northward shift in the jet stream. More frequent extreme summer heat events over mid-latitude continents are linked with reduced sea ice and snow through these circulation changes. © 2014 Macmillan Publishers Limited. All rights reserved.


Zhang Y.,University of Chinese Academy of Sciences | Yu R.,Chinese Academy of Meteorological Sciences | Li J.,Chinese Academy of Meteorological Sciences | Yuan W.,CAS Institute of Atmospheric Physics | Zhang M.,State University of New York at Stony Brook
Journal of Climate | Year: 2013

Given the large discrepancies that exist in climate models for shortwave cloud forcing over eastern China (EC), the dynamic (vertical motion and horizontal circulation) and thermodynamic (stability) relations of stratus clouds and the associated cloud radiative forcing in the cold season are examined. Unlike the stratus clouds over the southeastern Pacific Ocean (as a representative of marine boundary stratus), where thermodynamic forcing plays a primary role, the stratus clouds over EC are affected by both dynamic and thermodynamic factors. The Tibetan Plateau (TP)-forced low-level large-scale lifting and high stability overEC favor the accumulation of abundant saturated moist air, which contributes to the formation of stratus clouds. The TP slows down thewesterly overflow through a frictional effect, resulting inmidlevel divergence, and forces the low-level surrounding flows, resulting in convergence. Both midlevel divergence and low-level convergence sustain a rising motion and vertical water vapor transport over EC. The surface cold air is advected from the Siberian high by the surrounding northerly flow, causing low-level cooling. The cooling effect is enhanced by the blocking of theYunGui Plateau. The southwesterlywind carryingwarm, moist air fromthe eastBay ofBengal is uplifted by the HengDuan Mountains via topographical forcing; the midtropospheric westerly flow further advects thewarmair downstream of the TP, moistening andwarming themiddle troposphere on the lee side of the TP. The low-level cooling and midlevel warming together increase the stability. The favorable dynamic and thermodynamic large-scale environment allows for the formation of stratus clouds overECduring the cold season. © 2013 American Meteorological Society.


Duan J.,Chinese Research Academy of Environmental Sciences | Tan J.,University of Chinese Academy of Sciences
Atmospheric Environment | Year: 2013

In recent years, heavy metal pollution accidents were reported frequently in China. The atmospheric heavy metal pollution is drawing all aspects of attention. This paper summarizes the recent research results from our studies and previous studies in recent years in China. The level, temporal variation, seasonal variation and size distribution of the heavy metals of atmospheric Lead(Pb), Vanadium(V), Manganese(Mn), Nickel(Ni), Chromium(Cr), Cadmium(Cd), Copper(Cu), Zinc(Zn) and Arsenic(As) were characterized in China. The emission characteristics and sources of atmospheric heavy metals and As in China were reviewed. Coal burning, iron and steel industry and vehicle emission are important sources in China. Control policies and effects in China were reviewed including emission standards, ambient air quality standards, phase out of leaded gasoline and so on, and further works for atmospheric heavy metals control were suggested. The comprehensive heavy metals pollution control measures and suggestions were put forward based on the summarization of the development and experience of the atmospheric heavy metal pollution control abroad. © 2013 Elsevier Ltd.


Zeng X.,Hubei University | Carlet C.,French National Center for Scientific Research | Shan J.,Hubei University | Hu L.,University of Chinese Academy of Sciences
IEEE Transactions on Information Theory | Year: 2011

In this paper, three constructions of balanced Boolean functions with optimal algebraic immunity are proposed. It is checked that, at least for small numbers of input variables, these functions have good behavior against fast algebraic attacks as well. Other cryptographic properties such as algebraic degree and nonlinearity of the constructed functions are also analyzed. Lower bounds on the nonlinearity are proved, which are similar to the best bounds obtained for known Boolean functions resisting algebraic attacks and fast algebraic attacks. Moreover, it is checked that for the number n of variables with 5≤ n ≤ 19, the proposed n-variable Boolean functions have in fact very good nonlinearity. © 2011 IEEE.


Wang Y.,Zhengzhou University of Light Industry | Wu G.,University of Chinese Academy of Sciences
Journal of Mathematical Fluid Mechanics | Year: 2016

We are concerned with the problem, originated from Seregin (159–200, 2007), Seregin (J. Math. Sci. 143: 2961–2968, 2007), Seregin (Russ. Math. Surv. 62:149–168, 2007), what are minimal sufficiently conditions for the regularity of suitable weak solutions to the 3D Navier–Stokes equations. We prove some interior regularity criteria, in terms of either one component of the velocity with sufficiently small local scaled norm and the rest part with bounded local scaled norm, or horizontal part of the vorticity with sufficiently small local scaled norm and the vertical part with bounded local scaled norm. It is also shown that only the smallness on the local scaled L2 norm of horizontal gradient without any other condition on the vertical gradient can still ensure the regularity of suitable weak solutions. All these conclusions improve pervious results on the local scaled norm type regularity conditions. © 2016, Springer International Publishing.


Zhou T.,CAS Institute of Biophysics | Zhou T.,University of Chinese Academy of Sciences | Xiong J.,China National Institute of Biological Sciences | Wang M.,CAS Institute of Biophysics | And 4 more authors.
Molecular Cell | Year: 2014

Methylated cytosine of CpG dinucleotides in vertebrates may be oxidized by Tet proteins, a process that can lead to DNA demethylation. The predominant oxidation product, 5-hydroxymethylcytosine (5hmC), has been implicated in embryogenesis, cell differentiation, and human diseases. Recently, the SRA domain of UHRF2 (UHRF2-SRA) has been reported to specifically recognize 5hmC, but how UHRF2 recognizes this modification is unclear. Here we report the structure of UHRF2-SRA in complex with a 5hmC-containing DNA. The structure reveals that the conformation of a phenylalanine allows the formation of an optimal 5hmC binding pocket, and a hydrogen bond between the hydroxyl group of 5hmC and UHRF2-SRA is critical for their preferential binding. Further structural and biochemical analyses unveiled the role of SRA domains as a versatile reader of modified DNA, and the knowledge should facilitate further understanding of the biological function of UHRF2 and the comprehension of DNA hydroxymethylation in general. © 2014 Elsevier Inc.


Wu Y.,CAS Institute of Microbiology | Wu Y.,University of Chinese Academy of Sciences | Tefsen B.,CAS Institute of Microbiology | Shi Y.,CAS Institute of Microbiology | And 5 more authors.
Trends in Microbiology | Year: 2014

Shorebirds and waterfowls are believed to be the reservoir hosts for influenza viruses, whereas swine putatively act as mixing vessels. The recent identification of two influenza-like virus genomes (designated H17N10 and H18N11) from bats has challenged this notion. A crucial question concerns the role bats might play in influenza virus ecology. Structural and functional studies of the two major surface envelope proteins, hemagglutinin (HA) and neuraminidase (NA), demonstrate that neither has canonical HA or NA functions found in influenza viruses. However, putative functional modules and domains in other encoded proteins are conserved, and the N-terminal domain of the H17N10 polymerase subunit PA has a classical structure and function. Therefore, potential genomic reassortments of such influenza-like viruses with canonical influenza viruses cannot be excluded at this point and should be assessed. © 2014 Elsevier Ltd.


Zhang B.,CAS Changchun Institute of Applied Chemistry | Tan G.,Hong Kong Baptist University | Lam C.-S.,Hong Kong Baptist University | Yao B.,CAS Changchun Institute of Applied Chemistry | And 7 more authors.
Advanced Materials | Year: 2012

An extremely high-efficiency solution-processed white organic light-emitting diode (WOLED) is successfully developed by simultaneously using an ideal dendritic host material and a novel efficient orange phosphorescent iridium complex. The optimized device exhibits forward-viewing efficiencies of 70.6 cd A -1, 26.0%, and 47.6 lm W -1 at a luminance of 100 cd m -2, respectively, promising the low-cost solution-processed WOLEDs a bright future as the next generation of illumination sources. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Lu F.,CAS Institute of Genetics and Developmental Biology | Lu F.,University of Chinese Academy of Sciences | Cui X.,CAS Institute of Genetics and Developmental Biology | Zhang S.,CAS Institute of Genetics and Developmental Biology | And 3 more authors.
Nature Genetics | Year: 2011

Polycomb group (PcG)-mediated histone H3 lysine 27 trimethylation (H3K27me3) has a key role in gene repression and developmental regulation 1-4. There is evidence that H3K27me3 is actively removed in plants5-8, but it is not known how this occurs. Here we show that RELATIVE OF EARLY FLOWERING 6 (REF6), also known as Jumonji domain-containing protein 12 (JMJ12), specifically demethylates H3K27me3 and H3K27me2, whereas its metazoan counterparts, the KDM4 proteins, are H3K9 and H3K36 demethylases 9,10. Plants overexpressing REF6 resembled mutants defective in H3K27me3-mediated gene silencing. Genetic interaction tests indicated that REF6 acts downstream of H3K27me3 methyltransferases. Mutations in REF6 caused ectopic and increased H3K27me3 level and decreased mRNA expression of hundreds of genes involved in regulating developmental patterning and responses to various stimuli. Our work shows that plants and metazoans use conserved mechanisms to regulate H3K27me3 dynamics but use distinct subfamilies of enzymes. © 2011 Nature America, Inc. All rights reserved.


Zhuang W.,CAS Yantai Institute of Coastal Zone Research | Zhuang W.,Zaozhuang University | Zhuang W.,University of Chinese Academy of Sciences | Gao X.,CAS Yantai Institute of Coastal Zone Research
PLoS ONE | Year: 2014

The total concentrations and chemical forms of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the surface sediments of the Laizhou Bay and the surrounding marine area of the Zhangzi Island (hereafter referred to as Zhangzi Island for short) were obtained and multiple indices and guidelines were applied to assess their contamination and ecological risks. The sedimentary conditions were fine in both of the two studied areas according to the marine sediment quality of China. Whereas the probable effects level guideline suggested that Ni might cause adverse biological effects to occur frequently in some sites. All indices used suggested that Cd posed the highest environmental risk in both the Laizhou Bay and the Zhangzi Island, though Cd may unlikely be harmful to human and ecological health due to the very low total concentrations. The enrichment factor (EF) showed that a substantial portion of Cr was delivered from anthropogenic sources, whereas the risk assessment code (RAC) indicated that most Cr was in an inactive state that it may not have any adverse effect either. Moreover, the results of EF and geoaccumulation index were consistent with the trend of the total metal concentrations except for Cd, while the results of RAC and potential ecological risk factor did not follow the same trend of their corresponding total metal concentrations. We also evaluated the effects of using different indices to assess the environmental impact of these heavy metals. © 2014 Zhuang, Gao.


Dang Y.,University of Chinese Academy of Sciences | Wang Z.-X.,University of Chinese Academy of Sciences | Wang X.,University of Colorado at Denver
Organometallics | Year: 2012

Density functional theory (DFT) calculations (B3LYP, M06, and M06-L) have been performed to investigate the mechanism and origins of Z selectivity of the metathesis homodimerization of terminal olefins catalyzed by chelated ruthenium complexes. The chosen system is, without any simplification, the experimentally performed homocoupling reaction of 3-phenyl-1-propene with 1cat, a pivalate and N-heterocyclic carbene (NHC) chelated Ru precatalyst. The six-coordinate 1cat converts to a trigonal-bipyramidal intermediate (3) through initial dissociation and isomerization. The metathesis reaction of complex 3 with 3-phenyl-1-propene occurs in a side-bound mechanism and generates the trigonal-bipyramidal Ru-benzylidene complex 6. Complex 6 is the active catalyst for the subsequent side-bound metathesis with 3-phenyl-1-propene, which forms metallacyclobutanes that lead to the (Z)- and (E)-olefin homodimers. The transition states of cycloreversion leading to the (Z)- and (E)-olefins differ in energy by 2.2 kcal/mol, which gives rise to a calculated Z selectivity that agrees with experimental results. The Z selectivity stems from reduced steric repulsion in the transition state. The regeneration of complex 6 occurs along with the formation of the gaseous byproduct ethylene, whose evolution drives the overall reaction. As our results indicate, the chelating ligands are crucial for this new class of Ru catalysts to achieve Z-selective olefin metathesis, because they direct olefin attack, differentiate energies of the transition states and intermediates, and support the complexes in certain coordination geometries. © 2012 American Chemical Society.


Ye Q.,University of Chinese Academy of Sciences | Doermann D.,University of Maryland University College
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2015

This paper analyzes, compares, and contrasts technical challenges, methods, and the performance of text detection and recognition research in color imagery. It summarizes the fundamental problems and enumerates factors that should be considered when addressing these problems. Existing techniques are categorized as either stepwise or integrated and sub-problems are highlighted including text localization, verification, segmentation and recognition. Special issues associated with the enhancement of degraded text and the processing of video text, multi-oriented, perspectively distorted and multilingual text are also addressed. The categories and sub-categories of text are illustrated, benchmark datasets are enumerated, and the performance of the most representative approaches is compared. This review provides a fundamental comparison and analysis of the remaining problems in the field. © 2015 IEEE.


Dang Y.,University of Chinese Academy of Sciences | Wang Z.-X.,University of Chinese Academy of Sciences | Wang X.,University of Colorado at Denver
Organometallics | Year: 2012

In the new class of N-heterocyclic carbene (NHC) chelated ruthenium catalysts for Z-selective olefin metathesis, the nitrato-supported complex 3cat appears distinct from all the other carboxylato-supported analogues. We have performed DFT calculations (B3LYP and M06) to elucidate the mechanism of 3cat-catalyzed metathesis homodimerization of 3-phenyl-1-propene. The six-coordinate 3cat transforms via initial dissociation and isomerization into a trigonal-bipyramidal intermediate (5), from which two consecutive metathesis reactions via the side-bound mechanism lead to (Z)-PhCH2CH=CHCH 2Ph (major) and (E)- PhCH2CH=CHCH2Ph (minor). In the overall mechanism, 3cat functions similarly to the pivalate-supported analogue 1cat. The substitution of a smaller nitrato group does not change the side-bound olefin attack mechanism for either the initiation or homocoupling metathesis. The chelation of the NHC ligand causes this class of Ru catalysts to favor the side-bound over the bottom-bound mechanism. The calculated energetics corroborate the experimental observation that 3cat is somewhat more active than 1cat in catalyzing the homodimerization of 3-phenyl-1-propene. © 2012 American Chemical Society.


Li S.-A.,CAS Kunming Institute of Zoology | Li S.-A.,University of Chinese Academy of Sciences | Lee W.-H.,CAS Kunming Institute of Zoology | Zhang Y.,CAS Kunming Institute of Zoology
Antimicrobial Agents and Chemotherapy | Year: 2012

Antimicrobial peptides (AMPs) have been considered alternatives to conventional antibiotics for drug-resistant bacterial infections. However, their comparatively high toxicity toward eukaryotic cells and poor efficacy in vivo hamper their clinical application. OH-CATH30, a novel cathelicidin peptide deduced from the king cobra, possesses potent antibacterial activity in vitro. The objective of this study is to evaluate the efficacy of OH-CATH30 and its analog OH-CM6 against drug-resistant bacteria in vitro and in vivo. The MICs of OH-CATH30 and OH-CM6 ranged from 1.56 to 12.5 μg/ml against drug-resistant clinical isolates of several pathogenic species, including Escherichia coli, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. The MICs of OH-CATH30 and OH-CM6 were slightly altered in the presence of 25% human serum. OH-CATH30 and OHCM6 killed E. coli quickly (within 60 min) by disrupting the bacterial cytoplasmic membrane. Importantly, the 50% lethal doses (LD 50) of OH-CATH30 and OH-CM6 in mice following intraperitoneal (i.p.) injection were 120 mg/kg of body weight and 100 mg/kg, respectively, and no death was observed at any dose up to 160 mg/kg following subcutaneous (s.c.) injection. Moreover, 10 mg/kg OH-CATH30 or OH-CM6 significantly decreased the bacterial counts as well as the inflammatory response in a mouse thigh infection model and rescued infected mice in a bacteremia model induced by drug-resistant E. coli. Taken together, our findings demonstrate that the natural cathelicidin peptide OH-CATH30 and its analogs exhibit relatively low toxicity and potent efficacy in mouse models, indicating that they may have therapeutic potential against the systemic infections caused by drug-resistant bacteria. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


Qiao S.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Qiao S.,University of Chinese Academy of Sciences | Du Z.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Yang R.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology
Journal of Materials Chemistry A | Year: 2014

Two novel conjugated microporous networks, P-1 and P-2, with carbazole-spacer-carbazole topological model structures, were designed and prepared by FeCl3 oxidative coupling polymerization. Monomer m-1 (fluorenone spacer) was modified with a thiophene Grignard to form the fluorenyl tertiary alcohol monomer m-2, and this step can increase the polymerization branches from four to five and incorporate the polar -OH group into the building block. N2 adsorption isotherms show that, after modification, the Brunauer-Emmett-Teller (BET) surface area of P-2 (1222 m2 g -1) is two times that of P-1 (611 m2 g-1), and the total pore volume increases 1.63 times from 0.95 to 1.55 at P/P0 = 0.99. However, the domain pore size (centred at 1.19 nm) and the pore distribution of both networks are not changed. It demonstrates that the domain pore width may be determined by the size of the rigid carbazole-spacer-carbazole backbone, not the degree of crosslinking when the networks were prepared under same polymerization conditions in this system. Hydrogen physisorption isotherms of P-1 and P-2 show that the H2 storage can be up to 1.05 wt% and 1.66 wt% at 77 K and 1.1 bar, and the isosteric heat is 9.89 kJ mol-1 and 10.86 kJ mol-1, respectively. At 273 K and 1.1 bar, the CO 2 uptake capacity of P-2 can be up to 14.5 wt% which is 1.63 times that of P-1 under the same conditions. The H2 and CO2 uptake capacities of P-2 are among the highest reported for conjugated microporous networks under similar conditions. The CO2/CH4 and CO2/N2 selectivity results indicate that P-1 exhibits a slightly higher separation ability than P-2. There is often a trade-off between absolute uptake and selectivity in other microporous organic polymers. Fine design and tailoring the topological structure of the monomer can change the adsorption isosteric enthalpy and optimize the gas uptake performance. The obtained networks with the carbazole-spacer-carbazole rigid backbone show promise for potential use in clean energy applications and the environmental field. © 2014 The Royal Society of Chemistry.


Chen J.,CAS Guangzhou Institute of Geochemistry | Chen J.,University of Chinese Academy of Sciences | Xiao X.,CAS Guangzhou Institute of Geochemistry
Fuel | Year: 2014

Artificial shale samples with equivalent vitrinite reflectance values (VRo) ranging from 0.69% to 4.19% were obtained from an anhydrous pyrolysis experiment. Microporous and mesoporous characteristics of these samples were investigated by low-pressure nitrogen and carbon dioxide adsorption techniques. The result shows that the nanoporosity (microporosity plus mesoporosity) increases with thermal maturity after the oil window stage, and this increase is attributed to the formation of porosity within organic matter and/or mineral-organic matter groundmass, rather than in the pure clay minerals. By combining the gas generation and porosity evolution of these shales, a general model for formation and development of the nanoporosity is proposed. © 2014 Elsevier Ltd. All rights reserved.


Kang R.,CAS Beijing National Laboratory for Molecular | Kang R.,University of Chinese Academy of Sciences | Chen H.,CAS Beijing National Laboratory for Molecular | Shaik S.,Hebrew University of Jerusalem | Yao J.,CAS Beijing National Laboratory for Molecular
Journal of Chemical Theory and Computation | Year: 2011

Gold-substrate interaction is essential in gold-catalyzed organic transformations. This study uses high-level coupled cluster calculations with core-valence correlation and complete basis set (CBS) limit extrapolation as a reference, for assessing the performance of popular density functional theory (DFT) approximations for a variety of Au(I)/Au(III) complexes with unsaturated aliphatic hydrocarbon CnHm substrates (ethene, ethyne, and allene). The tested functionals cover from LDA to GGA and meta-GGA, and to hybrids and double hybrids (LSDA, PBE, M06-L, TPSS, B3LYP, PBE0, M06, M06-2X, TPSSh, B2-PLYP, B2GP-PLYP). Both the geometry and bond dissociation energy (De) of the Au-CnHm complexes are studied. Our findings show that B2GP-PLYP, PBE0, and B2-PLYP are the best performing functionals for this set of Au-CnHm complexes. DFT dispersion correction (DFT-D3), though very helpful for some functionals (e.g., B3LYP and B2-PLYP), does not uniformly improve the results of all functionals. Ab initio methods like MP2 and SCSMP2 are also tested. MP2 is found to be the worst performing method, and while SCSMP2 greatly improves the results, still its accuracy is lower than that of the best functionals, B2GP-PLYP, PBE0, and B2-PLYP. © 2011 American Chemical Society.


Gao T.-P.,Capital Normal University | Shih C.-K.,Capital Normal University | Xu X.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | Wang S.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | And 2 more authors.
Current Biology | Year: 2012

Parasite-host associations among insects and mammals or birds are well attended by neontological studies [1]. An Eocene bird louse compression fossil [2, 3] and several flea specimens from Eocene and Oligocene ambers [4-8], reported to date, are exceptionally similar to living louse and flea taxa. But the origin, morphology, and early evolution of parasites and their associations with hosts are poorly known [9, 10] due to sparse records of putative ectoparasites with uncertain classification in the Mesozoic, most lacking mouthpart information and other critical details of the head morphology [11-15]. Here we present two primitive flea-like species assigned to the Pseudopulicidae Gao, Shih et Ren familia nova (fam. nov.), Pseudopulex jurassicus Gao, Shih et Ren genus novum et species nova (gen. et sp. nov) from the Middle Jurassic [16] and P. magnus Gao, Shih et Ren sp. nov. from the Early Cretaceous in China [17]. They exhibit many features of ectoparasitic insects. Large body size and long serrated stylets for piercing tough and thick skin or hides of hosts suggest that these primitive ectoparasites might have lived on and sucked the blood of relatively large hosts, such as contemporaneous feathered dinosaurs and/or pterosaurs or medium-sized mammals (found in the Early Cretaceous, but not the Middle Jurassic). © 2012 Elsevier Ltd. All rights reserved.


Tolley A.J.,Case Western Reserve University | Wu D.-J.,University of Chinese Academy of Sciences | Zhou S.-Y.,Case Western Reserve University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We construct static, spherically symmetric black hole solutions in scalar extended ghost-free massive gravity and show the existence of hairy black holes in this class of extension. While the existence seems to be a generic feature, we focus on the simplest models of this extension and find that asymptotically flat hairy black holes can exist without fine-tuning the theory parameters, unlike the bi-gravity extension, where asymptotical flatness requires fine-tuning in the parameter space. Like the bi-gravity extension, we are unable to obtain asymptotically dS regular black holes in the simplest models considered, but it is possible to obtain asymptotically AdS black holes. © 2015 American Physical Society.


Tian Z.,University of Chinese Academy of Sciences | Wu W.,Washington State University | Wan W.,Washington State University | Li A.D.Q.,Washington State University
Journal of the American Chemical Society | Year: 2011

Precisely identifying biological targets and accurately extracting their relatively weak signals from complicated physiological environments represent daunting challenges in biological detection and biomedical diagnosis. Fluorescence techniques have become the method of choice and offer minimally invasive and ultrasensitive detections, thus, providing a wealth of information regarding the biological mechanisms in living systems. Despite fluorescence analysis has advanced remarkably, conventional detections still encounter considerable limitations. This stems from the fact that the fluorescence intensity signal (I) is sensitive and liable to numerous external factors including temperature, light source, medium characteristics, and dye concentration. The interferences exasperatingly undermine the precision of measurements, and frequently render the signal undetectable. For example, fluorescence from single-molecule emitters can be measured on glass substrates under optimum conditions, but single-molecule events in complicated physiological environments such as live cells can hardly be detected because of autofluorescence interference and other factors. Furthermore, traditional intensity (I) and wavelength (λ) measurements do not reveal the interactive nature between the donor and the acceptor. Thus, innovative detection strategies to circumvent these aforementioned limitations of the conventional techniques are critically needed. With the use of photoswitching-induced donor-acceptor-fluorescence double modulations, we present a novel strategy that introduces three additional physical parameters: modulation amplitude (A), phase shift (ΔΦ), and lock-in frequency (ω), and demonstrate that such a strategy can circumvent the limitation of the conventional fluorescence detection techniques. Together, these five physical quantities (I, λ, A, ΔΦ, ω) reveal insightful information regarding molecular interactive strength between the probe and the analyte and enable extracting weak-fluorescence spectra from large interfering noises in complex environments. © 2011 American Chemical Society.


Li N.,Southwest Jiaotong University | Tang X.,University of Chinese Academy of Sciences
IEEE Transactions on Information Theory | Year: 2011

Three classes of binary sequences of period 4N with optimal autocorrelation value/magnitude have been constructed by Tang and Gong based on interleaving certain kinds of sequences of period N , i.e., the Legendre sequence, twin-prime sequence and generalized GMW sequence. In this paper, by means of sequence polynomials of the underlying sequences, the properties of roots of the corresponding sequence polynomials of the interleaved sequences with period 4N and optimal autocorrelation value/magnitude are discussed in the splitting field of xN-1. As a consequence, both the minimal polynomials and linear complexities of these three classes of sequences are completely determined except for the case of the sequences obtained from the generalized GMW sequences. For the latter, the minimal polynomial and linear complexity can be specially obtained if the sequence is constructed based on m-sequences instead of generalized GMW sequences. © 2011 IEEE.


Feng J.-M.,CAS Institute of Atmospheric Physics | Wang Y.-L.,University of Chinese Academy of Sciences | Ma Z.-G.,CAS Institute of Atmospheric Physics | Liu Y.-H.,Henan Polytechnic University
Journal of Climate | Year: 2012

Together with economic development and accelerated urbanization, the urban population in China has been increasing rapidly, and anthropogenic heat released by large-scale energy consumption in cities is expected to be a vital factor affecting the climate. In this paper, the Weather Research and Forecasting (WRF) model coupled with the Urban Canopy Model (UCM) is employed to simulate the regional impacts on climate under the two scenarios: the underlying surface changes due to urbanization (USCU) and anthropogenic heat release (AHR). Three experiments were performed from December 2006 to December 2008. With respect to the USCU, the surface albedo and the available surface soil water decrease markedly. With the inclusion of AHR, the two scenarios give rise to increased surface temperatures over most areas of China. Especially in the urban agglomeration area of the Yangtze River delta, the combination of USCU and AHR could result in an increase of 2°C in the surface air temperature. The influence of AHR on surface air temperature in winter is greater than the influence of USCU without considering any extra sources of heat, but the opposite is found in summer. The combination of USCU and AHR leads to changes in the surface energy budget. They both increase sensible heat flux, but USCU decreases latent heat flux significantly, and AHR increases latent heat flux slightly. Nevertheless, under the influence of these two scenarios, the precipitation increases in some areas, especially in the Beijing-Tianjin-Hebei region, while it decreases in other areas, most notably the Yangtze River delta. © 2012 American Meteorological Society.


Su H.,CAS Guangzhou Institute of Geochemistry | Su H.,University of Chinese Academy of Sciences | Wang Y.,CAS Guangzhou Institute of Geochemistry
Journal of Geophysical Research: Oceans | Year: 2012

To estimate sea ice thickness over a large spatial scale is a challenge. In this paper, we propose a direct approach to effectively estimate sea ice thickness over a large spatial area of the Bohai Sea using EOS MODIS data. It is based on the model of an exponential relation between albedo and thickness of sea ice. Eighteen images of EOS MODIS L1B data in the 2009-2010 winter were used to estimate the sea ice thickness and to monitor its spatiotemporal evolution in the Bohai Sea. The estimated thickness results are in accordance with results based on the Lebedev and Zubov empirical models as well as the forecasting data from the National Marine Environmental Forecasting Centre of China. Model correlation coefficients (R2 = 0.864 and 0.858) and close similarity in thickness prediction attest to the reliability and applicability of the proposed method. The average ice thickness of the whole Bohai Sea ranged from 3 to 21 cm, with an estimated maximum about 40 cm in Liaodong Bay. Multiple-temporal maps of sea-ice thickness show that the sea ice formed initially along the coastline, and gradually expanded away from the shore. Sea ice first appeared in the Liaodong Bay, and hugged the coast southwards to Bohai and Laizhou Bay. During melting the inverse sequence occurred. Our results also show that sea ice coverage and thickness are significantly correlated with the value of , the difference between cumulative FDD (Freezing Degree Days) and TDD (Thawing Degree Days). © 2012. American Geophysical Union. All Rights Reserved.


Tian Z.,University of Chinese Academy of Sciences | Li A.D.Q.,Washington State University
Accounts of Chemical Research | Year: 2013

Because of its ultrasensitivity, fluorescence offers a noninvasive means to investigate biomolecular mechanisms, pathways, and regulations in living cells, tissues, and animals. However, real-world applications of fluorescence technologies encounter many practical challenges. For example, the intrinsic heterogeneity of biological samples always generates optical interferences. High background such as autofluorescence can often obscure the desired signals. Finally, the wave properties of light limit the spatial resolution of optical microscopy.The key to solving these problems involves using chemical structures that can modulate the fluorescence output. Photoswitchable fluorescent molecules that alternate their emissions between two colors or between bright-and-dark states in response to external light stimulation form the core of these technologies. For example, molecular fluorescence modulation can switch fluorophores on and off. This feature supports super-resolution, which enhances resolution by an order of magnitude greater than the longstanding diffraction-limit barrier. The reversible modulation of such probes at a particular frequency significantly amplifies the frequency-bearing target signal while suppressing interferences and autofluorescence.In this Account, we outline the fundamental connection between constant excitation and oscillating fluorescence. To create molecules that will convert a constant excitation into oscillating emission, we have synthesized photoswitchable probes and demonstrated them as proofs of concept in super-resolution imaging and frequency-domain imaging. First, we introduce the design of molecules that can convert constant excitation into oscillating emission, the key step in fluorescence modulation. Then we discuss various technologies that use fluorescence modulation: super-resolution imaging, dual-color imaging, phase-sensitive lock-in detection, and frequency-domain imaging. Finally, we present two biological applications to demonstrate the power of photoswitching-enabled fluorescence imaging. Because synthetic photoswitchable probes can be much smaller, more versatile, and more efficient at high-performance modulation experiments, they provide a complement to photoswitchable fluorescent proteins. Although new challenges remain, we foresee a bright future for photoswitching-enabled imaging and detection. © 2012 American Chemical Society.


Yuan B.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Yuan B.,University of Chinese Academy of Sciences | Wang S.-A.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Li F.-L.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology
Bioresource Technology | Year: 2013

It is hypothesized that introduction of an endoinulinase gene into Saccharomyces cerevisiae will improve its inulin utilization and ethanol fermentation through collaboration between the heterologous endoinulinase and the inherent invertase SUC2. The aim of this work was to test the hypothesis by introducing the endoinulinase gene inuA from Aspergillus niger into S. cerevisiae. The results showed that heterologous inuA expressed in S. cerevisiae selectively digested long chains of inulin into short fructooligosaccharides and parts of these fructooligosaccharides could be efficiently utilized by the yeast. This study demonstrated that collaboration between heterologous endoinulinase and inherent invertase improved inulin degradation and ethanol fermentation in S. cerevisiae. © 2013 Elsevier Ltd.


Zhang N.,University of Chinese Academy of Sciences | Li H.,U.S. Department of Agriculture
Landscape Ecology | Year: 2013

Landscape metric scalograms (the response curves of landscape metrics to changing grain size) have been used to illustrate the scale effects of metrics for real landscapes. However, whether they detect the characteristic scale of hierarchically structured landscapes remains uncertain. To address this question, the scalograms of 26 class-level metrics were systematically examined for a simple random landscape, seven hierarchical neutral landscapes, and the real landscape of the Xilin River Basin of Inner Mongolia, China. The results show that when the fraction of the focal patch type (P) is below a critical value (Pc), most metric scalograms are sensitive to change in single-scale and lower-level hierarchical structure and insensitive to change in higher-level hierarchical structure. The scalograms of only a few metrics measuring spatial aggregation and connectedness are sensitive to change in intermediate-level hierarchical structure. Most metric scalograms explicitly identify the characteristic scale of a single-scale landscape and fine or intermediate characteristic scales of a multi-scale landscape for both simulated and real landscapes. When P exceeds Pc, only some metrics detect scale and change in structure. The scalograms of total class area and Euclidean nearest-neighbor distance cannot detect scale or change in structure in either case. Landscape metric scalograms are useful for addressing scale issues, including illustrating the scale effects of spatial patterns, detecting multi-scale patterns, and developing possible scaling relations. © 2013 Springer Science+Business Media Dordrecht.


Huang X.-L.,CAS Guangzhou Institute of Geochemistry | Zhong J.-W.,CAS Guangzhou Institute of Geochemistry | Zhong J.-W.,University of Chinese Academy of Sciences | Xu Y.-G.,CAS Guangzhou Institute of Geochemistry
Geochimica et Cosmochimica Acta | Year: 2012

Weakened lithospheric zones such as the Dabie-Sulu orogenic belt and Tan-Lu fault zone played important roles in the destruction of the North China Craton (NCC) during the late Mesozoic. Early Cretaceous mafic intrusions in western Shandong, contemporary with extensive magmatism during the destruction of the NCC, delineate two spatially distinct mantle domains (EM1- and EM2-like) beneath the craton's interior and weakened lithospheric zones, respectively. The Jinan and Zouping gabbros from the craton interior (∼128Ma) show fractionated LREE and nearly flat HREE patterns ([La/Yb] N=2.94-8.95; [Dy/Yb] N=1.23-1.69) with notable negative Ta, Nb and Ti anomalies. They have strong negative ε Nd(t) (-15.7 to -7.1), low initial 87Sr/ 86Sr (0.7039-0.7060) and negative zircon ε Hf(t) of -20.0 to -6.2. These "crustal fingerprints" cannot be explained by crustal contamination, but were likely derived from a hybrid mantle source. Crustal delamination or detachment during the Early Paleoproterozoic might be responsible for the involvement of Early Precambrian crustal materials in the Mesozoic mantle source beneath the southeastern NCC. In comparison, the Early Cretaceous mafic igneous rocks from regions (e.g., Yinan, Mengyin and Fangcheng) adjacent to the Dabie-Sulu orogenic belt and Tan-Lu fault zone have higher 87Sr/ 86Sr ratios (0.7059-0.7119), suggesting modification of the lithospheric mantle by melts/fluids derived from the Yangtze crust. The Mesozoic crustal delamination may have triggered the destruction of the lithospheric root beneath the Dabie-Sulu orogenic belt, whereas the lithospheric thinning beneath the interior of the southeastern NCC is attributed to the thermo-mechanical erosion by lateral convective asthenosphere. © 2012 Elsevier Ltd.


Yang X.,CAS Kunming Institute of Zoology | Yang X.,University of Chinese Academy of Sciences | Lee W.-H.,CAS Kunming Institute of Zoology | Zhang Y.,CAS Kunming Institute of Zoology
Journal of Proteome Research | Year: 2012

Peptide agents are regarded as hopeful candidates to solve life-threatening resistance of pathogenic microorganisms to classic antibiotics due to their unique action mechanisms. Peptidomic and genomic investigation of natural antimicrobial peptides (AMPs) from amphibian skin secretions can provide a large amount of structure-functional information to design peptide antibiotics with therapeutic potential. In the present study, we identified a large number of AMPs from the skins of nine kinds of Chinese odorous frogs. Eighty AMPs were purified from three different odorous frogs and confirmed by peptidomic analysis. Our results indicated that post-translational modification of AMPs rarely happened in odorous frogs. cDNAs encoding precursors of 728 AMPs, including all the precursors of the confirmed 80 native peptides, were cloned from the constructed AMP cDNA libraries of nine Chinese odorous frogs. On the basis of the sequence similarity of deduced mature peptides, these 728 AMPs were grouped into 97 different families in which 71 novel families were identified. Out of these 728 AMPs, 662 AMPs were novel and 28 AMPs were reported previously in other frog species. Our results revealed that identical AMPs were widely distributed in odorous frogs; 49 presently identified AMPs could find their identical molecules in different amphibian species. Purified peptides showed strong antimicrobial activities against 4 tested microbe strains. Twenty-three deduced peptides were synthesized and their bioactivities, including antimicrobial, antioxidant, hemolytic, immunomodulatory and insulin-releasing activities, were evaluated. Our findings demonstrate the extreme diversity of AMPs in amphibian skins and provide plenty of templates to develop novel peptide antibiotics. © 2011 American Chemical Society.


Baumgartner J.,McGill University | Baumgartner J.,University of Minnesota | Zhang Y.,University of Chinese Academy of Sciences | Schauer J.J.,University of Wisconsin - Madison | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Air pollution in China and other parts of Asia poses large health risks and is an important contributor to global climate change. Almost half of Chinese homes use biomass and coal fuels for cooking and heating. China's economic growth and infrastructure development has led to increased emissions from coal-fired power plants and an expanding fleet of motor vehicles. Black carbon (BC) from incomplete biomass and fossil fuel combustion is the most strongly light-absorbing component of particulate matter (PM) air pollution and the second most important climate-forcing human emission. PM composition and sources may also be related to its human health impact. We enrolled 280 women living in a rural area of northwestern Yunnan where biomass fuels are commonly used. We measured their blood pressure, distance from major traffic routes, and daily exposure to BC (pyrolytic biomass combustion), water-soluble organic aerosol (organic aerosol from biomass combustion), and, in a subset, hopane markers (motor vehicle emissions) in winter and summer. BC had the strongest associationwith systolic blood pressure (SBP) (4.3 mmHg; P < 0.001), followed by PM mass and water-soluble organic mass. The effect of BC on SBP was almost three times greater in women living near the highway [6.2 mmHg; 95% confidence interval (CI), 3.6 to 8.9 vs. 2.6 mmHg; 95% CI, 0.1 to 5.2]. Our findings suggest that BC from combustion emissions is more strongly associated with blood pressure than PM mass, and that BC's health effects may be larger among women living near a highway and with greater exposure to motor vehicle emissions.


Han L.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Han L.,University of Chinese Academy of Sciences | Yang D.-P.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Liu A.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Liu A.,University of Chinese Academy of Sciences
Biosensors and Bioelectronics | Year: 2015

A novel three-dimensional (3D) hierarchical porous cobalt oxide (Co3O4) architecture was first synthesized through a simple, cost-effective and environmentally friendly leaf-templated strategy. The Co3O4 nanoparticles (30-100nm) with irregular shapes were interconnected with each other to form a 3D multilayer porous network structure, which provided high specific surface area and numerous electrocatalytic active sites. Subsequently, Co3O4 was successfully utilized as direct electrochemical sensing interface for non-enzymatic detection of H2O2 and glucose. By using chronoamperometry, the current response of the sensor at +0.31V was linear with H2O2 concentration within 0.4-200μM with a low limit of detection (LOD) of 0.24μM (S/N=3) and a high sensitivity of 389.7μAmM-1cm-2. Two linear ranges of 1-300μM (with LOD of 0.1μM and sensitivity of 471.5μAmM-1cm-2) and 4-12.5mM were found at +0.59V for glucose. In addition, the as-prepared sensor showed excellent stability and anti-interference performance for possible interferents such as ascorbic acid, uric acid, dopamine, acetaminophen and especially 0.15M chloride ions. Similarly, other various metal oxide nanostructures may be also prepared using this similar strategy for possible applications in catalysis, electrochemical sensors, and fuel cells. © 2014 Elsevier B.V.


Fan L.,CAS Kunming Institute of Zoology | Fan L.,University of Chinese Academy of Sciences | Yao Y.-G.,CAS Kunming Institute of Zoology
Mitochondrion | Year: 2011

MitoTool, a web-based bioinformatics platform, is designed for deciphering human mitochondrial DNA (mtDNA) data in batch mode. The platform has advantages in (i) parsing diverse types of mtDNA data; (ii) automatically classifying haplogroup according to mtDNA sequences or variants; (iii) discovering possibly missing variants of the samples with claimed haplogroups status; (iv) estimating the evolutionary conservation index, protein coding effect and potential pathogenicity of certain substitutions; (v) performing statistical analysis for haplogroup distribution frequency between case and control groups. Furthermore, it offers an integrated database for retrieving five types of mitochondrion-related information. The MitoTool is freely accessed at http://www.mitotool.org. © 2010.


Zhang X.-J.,University of Chinese Academy of Sciences | Tang Q.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Pan M.,Princeton University | Tang Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Journal of Hydrometeorology | Year: 2014

A long-term consistent and comprehensive dataset of land surface hydrologic fluxes and states will greatly benefit the analysis of land surface variables, their changes and interactions, and the assessment of land- atmosphere parameterizations for climate models. While some offline model studies can provide balanced water and energy budgets at land surface, few of them have presented an evaluation of the long-term interaction of water balance components over China. Here, a consistent and comprehensive land surface hydrologic fluxes and states dataset for China using the Variable Infiltration Capacity (VIC) hydrologic model driven by long-term gridded observation-based meteorological forcings is developed. The hydrologic dataset covers China with a 0.25° spatial resolution and a 3-hourly time step for 1952-2012. In the dataset, the simulated streamflow matches well with the observed monthly streamflow at the large river basins in China. Given the water balance scheme in the VIC model, the overall success at runoff simulations suggests that the long-term mean evapotranspiration is also realistically estimated. The simulated soil moisture generally reproduces the seasonal variation of the observed soil moisture at the ground stations where long-term observations are available. The modeled snow cover patterns and monthly dynamics bear an overall resemblance to the Northern Hemisphere snow cover extent data from the National Snow and Ice Data Center. Compared with global product of a similar nature, the dataset can provide a more reliable estimate of land surface variables over China. The dataset, which will be publicly available via the Internet, may be useful for hydroclimatological studies in China. © 2014 American Meteorological Society.


Chen T.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Wu J.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Zhang J.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Zhang J.,University of Chinese Academy of Sciences | Sun L.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology
Bioresource Technology | Year: 2014

The gasification kinetic analysis of the three pseudocomponents (hemicellulose, cellulose and lignin) of biomass decomposition in the agent of CO2 were investigated. The Multi-peaks method was used to fit the Gaussian distribution model of DTG curves. The Friedman method was used to estimate the effective Eα, and the master plot method was used for the determination of the kinetic model. The results showed that there were two reaction stages for semi-cellulose and lignin. The DTG curves of semicellulose and lignin cannot be fitted by Gaussian distribution model. The Eα were ranged from 80 to 220kJmol-1 for the three pseudocomponents. The Fn model could describe the kinetic process of stage I of semi-cellulose decomposition. Both cellulose and stage II of semicellulose decomposition could be described by An model and the two reaction stages of the lignin were fitted the Rn model very well. © 2013 Elsevier Ltd.


Zhang J.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Zhang J.,University of Chinese Academy of Sciences | Chen T.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Wu J.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology
Bioresource Technology | Year: 2014

Thermal decompositions of three components of biomass (cellulose, hemicellulose and lignin) were studied using nonisothermal thermogravimetric analysis (TGA) under both oxidative and inert atmospheres at a heating rate of 10Kmin-1. The multi-Gaussian-distributed activation energy model (DAEM)-reaction model was first developed to describe thermal decomposition behaviors of three components. Results showed that the presence of CO2 enhanced the thermal decompositions of three components in high temperature range, but made little difference in low temperature range. Decomposition behaviors under CO2 were analyzed by the two-stage reaction mechanism corresponding to the pyrolysis process of original materials and the gasification process of char. During gasification stage, CO2 was reduced to CO, which provided a possibility of a reduction in greenhouse gas emissions. In addition, more CO was produced, and therefore the thermal value of gas was improved. The findings imply that CO2 gasification technology of biomass has great research significance. © 2014 Elsevier Ltd.


He S.,CAS Changchun Institute of Applied Chemistry | He S.,University of Chinese Academy of Sciences | Hu C.,Jiangxi Normal University | Hou H.,Jiangxi Normal University | Chen W.,CAS Changchun Institute of Applied Chemistry
Journal of Power Sources | Year: 2014

3D carbon materials-supported MnO2 have promising application in energy storage as supercapacitor electrode materials. Here, we demonstrate a simple and scalable method to fabricate 3D carbon paper-supported MnO 2 nanosheets, which can be used as supercapacitor electrode materials with low cost and high capacitance performance. MnO2 nanosheets with thickness about a few nanometers are grown on the carbon paper substrate through the reaction between aqueous KMnO4 and carbon. With the present method, the self-supported MnO2 composites can be fabricated into supercapacitor electrodes directly without any binder and conductive agents. It is found that MnO2 content in the composites increases with the increasing of KMnO4 concentration. The supercapacitor based on the hybrid with a MnO2 content of 7.9% exhibits the largest specific capacitance of 306.6 F g-1 at 0.5 A g-1, and a high power density of 67.8 kW kg-1 at the maximum current density of 300 A g-1. Moreover, the supercapacitors exhibit capacitance retention above 95% after 6000 cycles, demonstrating high stability of the carbon paper-supported MnO2 nanosheets for supercapacitors. Such 3D carbon paper-based architectures have promising application in energy storage devices with high power density and stability. © 2013 Elsevier B.V. All rights reserved.


Shang X.,CAS Institute of Electronics | Song H.,University of Chinese Academy of Sciences
IET Radar, Sonar and Navigation | Year: 2011

The coherent radar detection against a background of compound-Gaussian clutter with inverse gamma texture is studied and three detectors: One-step generalised likelihood ratio test (1S-GLRT), maximum a posteriori GLRT (MAP-GLRT) and two-step GLRT (2S-GLRT) are proposed. The detectors have the same structure with their test statistics and modified thresholds, respectively, related to the scale and the shape parameters of the texture, which can also be formulated in a matched filter (MF) form. Subsequently, the performance assessments are given by their probability of detection and probability of false alarm. The authors find that the probability of false alarm is dependent on the shape parameter, meaning the detectors have no CFAR property. When the shape parameter and the number of the integrated radar pulses satisfy certain condition, it has no relation with the shape parameter and then the detectors have CFAR property. Finally, simulation results show that: (i) 1S-GLRT and MAP-GLRT have the same performance for fixed probability of false alarm and 2S-GLRT bears slightly bad performance; (ii) the performance of 1S-GLRT is much closer to the adaptive coherence estimator (ACE) and is better than that of the Kelly GLRT and (iii) the 1S-GLRT is robust when parameter estimation errors exist. © 2011 The Institution of Engineering and Technology.


Gao Z.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Gao Z.,University of Chinese Academy of Sciences | Zhao H.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Li Z.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | And 2 more authors.
Energy and Environmental Science | Year: 2012

The rapidly growing demand for energy and the environmental concerns about carbon dioxide emissions make the development of renewable biofuels more and more attractive. Tremendous academic and industrial efforts have been made to produce bioethanol, which is one major type of biofuel. The current production of bioethanol is limited for commercialization because of issues with food competition (from food-based biomass) or cost effectiveness (from lignocellulose-based biomass). In this report we applied a consolidated bioprocessing strategy to integrate photosynthetic biomass production and microbial conversion producing ethanol together into the photosynthetic bacterium, Synechocystis sp. PCC6803, which can directly convert carbon dioxide to ethanol in one single biological system. A Synechocystis sp. PCC6803 mutant strain with significantly higher ethanol-producing efficiency (5.50 g L -1, 212 mg L-1 day-1) compared to previous research was constructed by genetically introducing pyruvate decarboxylase from Zymomonas mobilis and overexpressing endogenous alcohol dehydrogenase through homologous recombination at two different sites of the chromosome, and disrupting the biosynthetic pathway of poly-β-hydroxybutyrate. In total, nine alcohol dehydrogenases from different cyanobacterial strains were cloned and expressed in E. coli to test ethanol-producing efficiency. The effects of different culturing conditions including tap water, metal ions, and anoxic aeration on ethanol production were evaluated. © The Royal Society of Chemistry 2013.


Gao Y.,CAS Guangzhou Institute of Geochemistry | Gao Y.,University of Chinese Academy of Sciences | Ji Y.,CAS Guangzhou Institute of Geochemistry | Li G.,CAS Guangzhou Institute of Geochemistry | An T.,CAS Guangzhou Institute of Geochemistry
Water Research | Year: 2014

The mechanisms and kinetics of OH-initiated transformation of triclosan (TCS) in aquatic environments were modeled using high-accuracy molecular orbital theory. TCS can be initially attacked by OH in two ways, OH-addition and H-abstraction. Twelve OH-addition routes were reported, and the C atom adjacent to the ether bond in the benzene ring (RaddB1) was found as the most easily attacked position by OH, producing TCS-OHB1. Seven H-abstraction routes were reported, and the OH exclusively abstracted the phenolic hydroxyl (RabsOH) H atom, to form TCS(-H). The kinetics results showed that the RaddB1 and RabsOH routes would occur preferentially in aquatic environments, and the half-life depended on the OH concentration ([OH]). At low [OH], the main intermediates, TCS-OHB1 and TCS(-H), can be converted into 2,4-dichlorophenol and polychlorinated dibenzo-p-dioxins, respectively. However, when enough OH is present, such as in advanced oxidation process (AOP) systems, they would be fully decomposed. The acute and chronic toxicities of TCS and its products were assessed at three trophic levels using the "ecological structure-activity relationships" program. The toxicity of the products decreased through the RaddB1 route, while the toxicity of the products first increased and then decreased through the other degradation routes. These results should help reveal the mechanism of TCS transformation as well as risk assessment in aquatic environments, and will help design further experimental studies and industrial application of AOPs. © 2013 Elsevier Ltd.


Chen T.,CAS Guangzhou Institute of Geochemistry | Chen T.,University of Chinese Academy of Sciences | Yan B.,CAS Guangzhou Institute of Geochemistry
Waste Management | Year: 2012

Fixation of heavy metals in the slag produced during incineration of sewage sludge will reduce emission of the metals to the atmosphere and make the incineration process more environmentally friendly. The effects of incineration conditions (incineration temperature 500-1100 °C, furnace residence time 0-60. min, mass fraction of water in the sludge 0-75%) on the fixation rates and species partitioning of Cd, Pb, Cr, Cu, Zn, Mn and Ni in slag were investigated. When the incineration temperature was increased from 500 to 1100 °C, the fixation rate of Cd decreased from 87% to 49%, while the fixation rates of Cu and Mn were stable. The maximum fixation rates for Pb and Zn and for Ni and Cr were reached at 900 and 1100 °C, respectively. The fixation rates of Cu, Ni, Cd, Cr and Zn decreased as the residence time increased. With a 20. min residence time, the fixation rates of Pb and Mn were low. The maximum fixation rates of Ni, Mn, Zn, Cu and Cr were achieved when the mass fraction of water in the sludge was 55%. The fixation rate of Cd decreased as the water mass fraction increased, while the fixation rate of Pb increased. Partitioning analysis of the metals contained in the slag showed that increasing the incineration temperature and residence time promoted complete oxidation of the metals. This reduced the non-residual fractions of the metals, which would lower the bioavailability of the metals. The mass fraction of water in the sludge had little effect on the partitioning of the metals. Correlation analysis indicated that the fixation rates of heavy metals in the sludge and the forms of heavy metals in the incinerator slag could be controlled by optimization of the incineration conditions. These results show how the bioavailability of the metals can be reduced for environmentally friendly disposal of the incinerator slag. © 2011 Elsevier Ltd.


Bao L.-J.,CAS Guangzhou Institute of Geochemistry | Zeng E.Y.,University of Chinese Academy of Sciences
TrAC - Trends in Analytical Chemistry | Year: 2011

With compiled and analyzed information about recent advances in passive sampling techniques for sediment porewater, we discuss common quantitation methods (equilibrium and kinetic diffusion-controlled sampling), effects of temperature and salinity on passive sampling, and benefits and drawbacks of currently available passive samplers based on the principles of solid-phase microextraction.The results show that the in-fiber standardization technique, which is kinetic diffusion-controlled, could shorten sampling time and obtain accurate results using isotopically-labeled reference compounds. Another quantitative method, time-weighted average sampling, may be viable for simultaneously measuring all analytes in sediment porewater, as it is more effective with respect to cost and time. In addition, the effects of temperature and salinity on passive sampling should be quantified in field applications.Currently available passive samplers (e.g., employing polymer-coated fibers and low-density polyethylene sheets) can sense hydrophobic organic chemicals (HOCs) in sediment porewater, but the small capacity and the inflexibility of polymer-coated fibers need to be further improved, while better physical protection of polyethylene devices, particularly when they are deployed under rough conditions, should be carefully considered.In conclusion, passive samplers for in-situ measurement of dissolved HOCs in sediment porewater should be combined with a suitable quantitative method and calibration for the effects of temperature and salinity. © 2011 Elsevier Ltd.


Gao Y.C.,CAS Institute of Geographical Sciences and Natural Resources Research | Liu M.F.,CAS Institute of Geographical Sciences and Natural Resources Research | Liu M.F.,University of Chinese Academy of Sciences | Liu M.F.,Princeton University
Hydrology and Earth System Sciences | Year: 2013

High-resolution satellite precipitation products are very attractive for studying the hydrologic processes in mountainous areas where rain gauges are generally sparse. Four high-resolution satellite precipitation products are evaluated using gauge measurements over different climate zones of the Tibetan Plateau (TP) within a 6 yr period from 2004 to 2009. The four satellite-based precipitation data sets are: Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis 3B42 version 6 (TMPA) and its Real Time version (TMPART), Climate Prediction Center Morphing Technique (CMOPRH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network (PERSIANN). TMPA and CMORPH, with higher correlation coefficients and lower root mean square errors (RMSEs), show overall better performance than PERSIANN and TMPART. TMPA has the lowest biases among the four precipitation data sets, which is likely due to the correction process against the monthly gauge observations from global precipitation climatology project (GPCP). TMPA also shows large improvement over TMPART, indicating the importance of gauge-based correction on accuracy of rainfall. The four products show better agreement with gauge measurements over humid regions than that over arid regions where correlation coefficients are less than 0.5. Moreover, the four precipitation products generally tend to overestimate light rainfall (0-10 mm) and underestimate moderate and heavy rainfall (>10 mm). Moreover, this study extracts 24 topographic variables from a DEM (digital elevation model) and uses a linear regression model to explore the bias-topography relationship. Results show that biases of TMPA and CMORPH present weak dependence on topography. However, biases of TMPART and PERSIANN present dependence on topography and variability of elevation and surface roughness plays important roles in explaining their biases. © 2013 Author(s).


Wang W.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Liu X.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Liu X.,University of Chinese Academy of Sciences | Lu X.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology
Biotechnology for Biofuels | Year: 2013

Background: Cyanobacteria can utilize solar energy and convert carbon dioxide into biofuel molecules in one single biological system. Synechocystis sp. PCC 6803 is a model cyanobacterium for basic and applied research. Alkanes are the major constituents of gasoline, diesel and jet fuels. A two-step alkane biosynthetic pathway was identified in cyanobacteria recently. It opens a door to achieve photosynthetic production of alka(e)nes with high efficiency by genetically engineering cyanobacteria. Results: A series of Synechocystis sp. PCC6803 mutant strains have been constructed and confirmed. Overexpression of both acyl-acyl carrier protein reductase and aldehyde-deformylating oxygenase from several cyanobacteria strains led to a doubled alka(e)ne production. Redirecting the carbon flux to acyl- ACP can provide larger precursor pool for further conversion to alka(e)nes. In combination with the overexpression of alkane biosynthetic genes, alka(e)ne production was significantly improved in these engineered strains. Alka(e)ne content in a Synechocystis mutant harboring alkane biosynthetic genes over-expressed in both slr0168 and slr1556 gene loci (LX56) was 1.3% of cell dry weight, which was enhanced by 8.3 times compared with wildtype strain (0.14% of cell dry weight) cultivated in shake flasks. Both LX56 mutant and the wildtype strain were cultivated in column photo-bioreactors, and the alka(e)ne production in LX56 mutant was 26 mg/L (1.1% of cell dry weight), which was enhanced by 8 times compared with wildtype strain (0.13% of cell dry weight). Conclusions: The extent of alka(e)ne production could correlate positively with the expression level of alkane biosynthetic genes. Redirecting the carbon flux to acyl-ACP and overexpressing alkane biosynthetic genes simultaneously can enhance alka(e)ne production in cyanobacteria effectively. © 2013 Wang et al.; licensee BioMed Central Ltd.


Wei G.-L.,CAS Guangzhou Institute of Geochemistry | Zeng E.Y.,University of Chinese Academy of Sciences
TrAC - Trends in Analytical Chemistry | Year: 2011

This critical overview covers current analytical methods and future developments in quantitative determination of fatty acids (FAs), emphasizing sample extraction, derivatization and instrumental analysis with gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS2). We compare the benefits and the drawbacks of these two analytical techniques.We consider the well-established GC/MS method with pre-derivatization to be a traditional technique in terms of highly standardized sample-preparation procedures, affordability and readily available library searching for compound identification. However, the complicated derivatization steps required prior to instrumental analysis with GC/MS take a long time, with loss and transformation of FAs, low recovery and poor reproducibility.HPLC/MS2 without derivatization shows the benefits of simple, mild sample-processing conditions, satisfactory recovery, short running time and high selectivity and sensitivity, which may allow it to become a viable alternative to GC/MS for the analysis of FAs in the years ahead. © 2011 Elsevier Ltd.


Wang Q.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Wang Q.,CAS Guangzhou Institute of Geochemistry | Wang Q.,University of Chinese Academy of Sciences
Renewable and Sustainable Energy Reviews | Year: 2010

China, one of the global biggest emitter of CO2, needs promotion renewable energy to reduce air pollution from its surging fossil fuel use, and to increase its energy supply security. Renewable energy in its infancy needs policy support and market cultivation. Wind power installed capacity has boomed in recent year in China, as a series of effective support policies were adopted. In this paper, I review the main renewable energy policies regarding to China's wind power, including the Wind Power Concession Program, Renewable Energy Law, and a couple of additional laws and regulations. Such policies have effectively reduced the cost of wind power installed capacity, stimulated the localization of wind power manufacture, and driven the company investment in wind power. China is success in wind power installed capacity, however, success in wind-generated electricity has yet achieved, mainly due to the backward grid system and lack of quota system. The paper ends with the recommended best practice of the China's wind power installed capacity might be transferable to China's photovoltaic power generation. © 2009 Elsevier Ltd. All rights reserved.


Hu E.,CAS Guangzhou Institute of Geochemistry | Hu E.,University of Chinese Academy of Sciences | Cheng H.,CAS Guangzhou Institute of Geochemistry
Water Research | Year: 2014

With their high catalytic activity for redox reactions, transition metal ions (Cu2+ and Fe3+) were exchanged into the micropores of dealuminated Y zeolites to prepare effective microporous mineral sorbents for sorption and microwave-induced degradation of atrazine. Due to its ability to complex with atrazine, loading of copper greatly increased the sorption of atrazine. Atrazine sorption on iron-exchanged zeolites was also significantly enhanced, which was attributed to the hydrolysis of Fe3+ polycations in mineral micropores and electrostatic interactions of protonated atrazine molecules with the negatively charged pore wall surface. Copper and iron species in the micropores also significantly accelerated degradation of the sorbed atrazine (and its degradation intermediates) under microwave irradiation. The catalytic effect was attributed to the easy reducibility and high oxidation activity of Cu2+ and Fe3+ species stabilized in the micropores of the zeolites. It was postulated that the surface species of transition metals (monomeric Cu2+, Cu2+-O-Cu2+ complexes, FeO+, and dinuclear Fe-O-Fe-like species) in the mineral micropores were thermally activated under microwave irradiation, and subsequently formed highly reactive sites catalyzing oxidative degradation of atrazine. The transition metal-exchanged zeolites, particularly the iron-exchanged ones, were relatively stable when leached under acidic conditions, which suggests that they are reusable in sorption and microwave-induced degradation. These findings offer valuable insights on designing of effective mineral sorbents that can selectively uptake atrazine from aqueous solutions and catalyze its degradation under microwave irradiation. © 2014 Elsevier Ltd.


Zhou G.,University of Chinese Academy of Sciences | Chung W.,University of Hong Kong | Zhang Y.,Beijing Institute of Technology
Expert Systems with Applications | Year: 2014

This study presents an application of data envelopment analysis (DEA) approach with considering undesirable outputs, and not only examines the energy efficiency performance of China's transport sector from 2003 to 2009, but also maximizes energy-saving potential of transport sector of China's 30 administrative regions. Environmental DEA technology is adopted, which treats undesirable measures by distinguishing between weak and strong disposability. The output directional distance function is used, which explicitly expands desirable outputs and simultaneously reduces undesirable outputs. From the empirical results, the lowest number of efficient regions was recorded in 2007 or 2008, which eventually slightly recovered. Similarly, the overall average energy efficiency reached the lowest record in 2007 or 2008. These results are consistent with the policy guidance in the 11th Five-Year Plan (2006-2010) period that a series of new policies in the transport sector are implemented to reverse the trend of energy intensity increase. The Eastern area generally performed better than the Central area and Western area. The Central area was better than the Western area, except in some critical years such as in 2008, the financial crisis significantly affected port turnover. The total potential energy saving from 2003 to 2009 was 35.72 Mtce, the total potential energy saving was approximately 2.75% of the total transport energy use. © 2013 Elsevier Ltd. All rights reserved.


Xu R.,CAS Xishuangbanna Tropical Botanical Garden | Xu R.,University of Chinese Academy of Sciences | Wang R.,CAS Xishuangbanna Tropical Botanical Garden | Liu A.,CAS Xishuangbanna Tropical Botanical Garden
Biomass and Bioenergy | Year: 2011

Jatropha (Jatropha curcas L., Euphorbiaceae), a potential biodiesel plant, has created tremendous interest all over the world for the use of its seed oil as a commercial source of biodiesel. Due to the unreliability of oil content in its seeds and low economic returns planting of jatropha in agriculture was restricted. Investigating the molecular basis of storage lipid accumulation during seed development is an immediate need to understand genetic factors regulating storage lipid biosynthesis in jatropha seeds. In this study, we characterized the seed development and lipid accumulation from female flowers pollinated to mature seeds, and investigated temporal expression profiles of 21 lipid genes involved in different steps of the pathways leading to fatty acid and TAG synthesis within jatropha developing seeds using quantitative real-time PCR technology. Concomitantly, 17 genes increased their expression levels in developing seeds compared to their expression in leaf, but showed various temporal expression patterns and different relative-maximum ratio ranging from 2.8 to 1,919,280-fold in developing seeds. Five gene groups with distinct temporal patterns were identified by clustering analysis of expression data. Two gene groups including 15 genes presented up-regulated expression patterns correlated with storage lipid accumulation in developing seeds. This study provided not only the initial information on promoter activity for each gene, but also a first glimpse of the global patterns of gene expression and regulation, which are critical to understand the molecular basis of lipid biosyntheses, identifying the rate-limiting genes during seed development and to create improved varieties by genetic engineering. © 2011 Elsevier Ltd.


Ma W.,CAS Lanzhou Institute of Chemical Physics | Ma W.,University of Chinese Academy of Sciences | Lu J.,CAS Lanzhou Institute of Chemical Physics
Wear | Year: 2011

Metal matrix composites (MMC) containing graphite particulates usually have reduced friction under dry sliding, which is closely dependent on the formation of continuous transfer layer on the sliding surface of counterpart. The transfer process, understandably, may be affected by the actual variance of texture on counterpart surface. Thus the transfer behaviour of Cu-graphite composite onto steel discs with different textures was investigated, where the evolution of the transfer layers on the counterparts with different textures under both low and high loads was highlighted. It was found that the textures had different ratcheting effects on the contact surface of Cu-graphite composite, which led to diverse extent of extruded surface layer and size of extruded sliver. Moreover, fractured sliver acted as the precursor of the transfer layer and played a key role in determining the continuity of the transfer layer, which in turn led to different friction and wear behaviour of the composite sliding against steel counterparts with different textures. © 2010 Elsevier B.V.


Ma W.,CAS Lanzhou Institute of Chemical Physics | Ma W.,University of Chinese Academy of Sciences | Lu J.,CAS Lanzhou Institute of Chemical Physics
Tribology Letters | Year: 2011

In practice, the sliding speed is an important parameter for materials applied in sliding condition. We have conducted an experimental study to explore the effect of sliding speed on friction and wear performance of a copper-graphite composite. The sliding tests were carried out over a wide range of speeds with a pin-on-disc configuration. The results show that there is a critical speed at which there is a transition of the friction and wear regimes of the composite. In addition, the formation of a lubricant layer on the contact surface (surface modification) determines the actual tribological performance of the composite. The wear mechanisms in different wear regimes are also discussed. © 2010 Springer Science+Business Media, LLC.


Cui L.,CAS Lanzhou Institute of Chemical Physics | Cui L.,University of Chinese Academy of Sciences | Lu Z.,CAS Lanzhou Institute of Chemical Physics | Wang L.,CAS Lanzhou Institute of Chemical Physics
ACS Applied Materials and Interfaces | Year: 2013

The high friction of diamondlike carbon (DLC) films in vacuum impedes achieving their application in space environment. Here we show that the vacuum friction coefficients can be lowered below 0.1 by avoiding formation of carbonaceous transfer layers on the counterfaces. First-principles calculations reveal that the low friction coefficients stem from intrinsically weak-interacting sliding interfaces. Conversely, formation of transfer layers and carbonaceous sliding interfaces thus established are invalid for friction reduction for DLC in vacuum. The mating materials are thus highlighted for their crucial roles in transfer-layer formation. © 2013 American Chemical Society.


Zhang Y.,CAS Lanzhou Institute of Chemical Physics | Cui X.,CAS Lanzhou Institute of Chemical Physics | Cui X.,University of Chinese Academy of Sciences | Shi F.,CAS Lanzhou Institute of Chemical Physics | Deng Y.,CAS Lanzhou Institute of Chemical Physics
Chemical Reviews | Year: 2012

A study was conducted to demonstrate the use of nano-gold catalysis in fine chemical synthesis. The selective hydrogenation of 1,3-butadiene in the presence of a large excess of propene using nano-gold catalysts was investigated. The model system was composed with 0.3% butadiene, 30% propene, 20% hydrogen, and balanced with 49.7% helium. It was shown that supported nano-gold catalysts prepared with the deposition-precipitation (DP) method exhibited better catalytic performance. Nano-gold particles were supported onto Mg 2AlO hydrotalcite for the liquid-phase crotonaldehyde hydrogenation. The Au/Mg 2AlO catalyst exhibited much higher catalytic activity in comparison with nano-gold supported on FeOOH, Fe 2O 3, CeO 2, TiO 2, and Al 2O 3.


Hu X.,CAS Lanzhou Institute of Chemical Physics | Hu X.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
Applied Catalysis B: Environmental | Year: 2010

The reaction of acetic acid steam reforming for H2 production has been investigated over transition metal catalysts (Ni, Co, Fe or Cu)/Al2O3. Ni/Al2O3 and Co/Al2O3 catalysts are active for acetic acid steam reforming while Fe/Al2O3 and Cu/Al2O3 catalysts present negligible activity. The difference can be attributed to the different cracking activity of the metals toward the C-C and C-H bonds of acetic acid molecule. Detailed comparisons in terms of catalytic activity, selectivity, and stability are carried out over Ni/Al2O3 and Co/Al2O3 catalysts. Distinct product distributions were observed between them. CH4 production was favored over Ni/Al2O3 catalyst at mild temperatures while CO production was favored over Co/Al2O3 catalyst at high temperatures, which were induced by the different reaction networks over the two catalysts. Moreover, in the stability tests, Ni/Al2O3 catalyst was much more stable than Co/Al2O3 catalyst. Serious coke deposition and oxidation of metallic phase led to the fast deactivation of Co/Al2O3 catalyst. On the contrary, much slower coke formation rates and metal sintering rates as well as much higher resistivity of active metal toward oxidation guaranteed the stability of Ni/Al2O3 catalyst. © 2010 Elsevier B.V.


Zhang M.,CAS Lanzhou Institute of Chemical Physics | Zhang M.,University of Chinese Academy of Sciences | Liang X.,CAS Lanzhou Institute of Chemical Physics | Jiang S.,CAS Lanzhou Institute of Chemical Physics | Qiu H.,CAS Lanzhou Institute of Chemical Physics
TrAC - Trends in Analytical Chemistry | Year: 2014

Ionic liquids (ILs) are a class of substances completely comprised of ions. Due to their unique properties (e.g., electric conductivity, low volatility, thermostability and tenability), their use has attracted considerable interest, including an increasing number of publications on their use in preparing stationary phases (SPs) of high-performance liquid chromatography. We highlight the existing pathways for making IL-based SPs, and we propose potential strategies for synthesis. We also give up-to-date information on their applications in different chromatographic modes. © 2013 Elsevier Ltd.


Fan X.,CAS Lanzhou Institute of Chemical Physics | Fan X.,University of Chinese Academy of Sciences | Wang L.,CAS Lanzhou Institute of Chemical Physics
ACS Applied Materials and Interfaces | Year: 2014

Although ionic liquids (ILs) as a class of promising materials have a wide range of applications due to the excellent properties, their potential as space lubricants has been not systematically explored. Here two kinds of conductive alkyl imidazolium ILs greases were prepared using 1-hexyl-3-methylimidazolium tetrafluoroborate (LB106) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide (L-F106) as base oil and the polytetrafluoroethylene (PTFE) as thickener, with multiple-alkylated cyclopentane grease (MACs) as a comparison. Their chemical composition and tribological properties were investigated in detail under simulated space environment which is composed of high vacuum, high temperature and irradiation. Results show that the high conductive ILs greases not only possess good adaptive abilities to space environment and thermal stability but also provide excellent friction reducing and antiwear behaviors as well as high load carrying capacities. The unique physicochemical properties are attributed to a combination of special anions and cations, the excellent tribological properties are strongly dependent on a boundary protective film on the rubbing surfaces. © 2014 American Chemical Society.


Wang W.,CAS Lanzhou Institute of Chemical Physics | Wang W.,University of Chinese Academy of Sciences | Wang A.,CAS Lanzhou Institute of Chemical Physics
Carbohydrate Polymers | Year: 2010

A pH-sensitive semi-interpenetrating polymer network (semi-IPN) superabsorbent hydrogel composed of sodium alginate-g-poly(sodium acrylate) (NaAlg-g-PNaA) network and linear polyvinylpyrrolidone (PVP) was prepared by free-radical solution polymerization in the presence of initiator ammonium persulfate (APS) and crosslinker N,N-methylene-bis-acrylamide (MBA). FTIR results revealed that PNaA had been grafted onto NaAlg macromolecular chains and PVP was penetrated throughout the NaAlg-g-PNaA network by a hydrogen binding action. The surface morphologies of the hydrogels were improved due to the incorporation of PVP as shown by SEM observation. The introduction of PVP and the formation of semi-IPN structure greatly improved the water absorption and swelling rate of the hydrogel. The hydrogel possesses remarkable sensitivity to external pH stimulus and shows reversible On-Off switching swelling characteristic. An intriguing time-dependent swelling behavior of the semi-IPN hydrogel was observed in multi-valence saline and cationic surfactant solutions, but the similar time-dependent behaviors are resulting from two distinct mechanisms. © 2010 Elsevier Ltd. All rights reserved.


Cao Y.-Q.,CAS Xishuangbanna Tropical Botanical Garden | Cao Y.-Q.,University of Chinese Academy of Sciences | Ma C.,CAS Institute of Zoology | Chen J.-Y.,CAS Xishuangbanna Tropical Botanical Garden | Yang D.-R.,CAS Xishuangbanna Tropical Botanical Garden
BMC Genomics | Year: 2012

Background: Lepidoptera encompasses more than 160,000 described species that have been classified into 45-48 superfamilies. The previously determined Lepidoptera mitochondrial genomes (mitogenomes) are limited to six superfamilies of the lineage Ditrysia. Compared with the ancestral insect gene order, these mitogenomes all contain a tRNA rearrangement. To gain new insights into Lepidoptera mitogenome evolution, we sequenced the mitogenomes of two ghost moths that belong to the non-ditrysian lineage Hepialoidea and conducted a comparative mitogenomic analysis across Lepidoptera.Results: The mitogenomes of Thitarodes renzhiensis and T. yunnanensis are 16,173 bp and 15,816 bp long with an A + T content of 81.28 % and 82.34 %, respectively. Both mitogenomes include 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and the A + T-rich region. Different tandem repeats in the A + T-rich region mainly account for the size difference between the two mitogenomes. All the protein-coding genes start with typical mitochondrial initiation codons, except for cox1 (CGA) and nad1 (TTG) in both mitogenomes. The anticodon of trnS(AGN) in T. renzhiensis and T. yunnanensis is UCU instead of the mostly used GCU in other sequenced Lepidoptera mitogenomes. The 1,584-bp sequence from rrnS to nad2 was also determined for an unspecified ghost moth (Thitarodes sp.), which has no repetitive sequence in the A + T-rich region. All three Thitarodes species possess the ancestral gene order with trnI-trnQ-trnM located between the A + T-rich region and nad2, which is different from the gene order trnM-trnI-trnQ in all previously sequenced Lepidoptera species. The formerly identified conserved elements of Lepidoptera mitogenomes (i.e. the motif 'ATAGA' and poly-T stretch in the A + T-rich region and the long intergenic spacer upstream of nad2) are absent in the Thitarodes mitogenomes.Conclusion: The mitogenomes of T. renzhiensis and T. yunnanensis exhibit unusual features compared with the previously determined Lepidoptera mitogenomes. Their ancestral gene order indicates that the tRNA rearrangement event(s) likely occurred after Hepialoidea diverged from other lepidopteran lineages. Characterization of the two ghost moth mitogenomes has enriched our knowledge of Lepidoptera mitogenomes and contributed to our understanding of the mechanisms underlying mitogenome evolution, especially gene rearrangements. © 2012 Cao et al.; licensee BioMed Central Ltd.


Wang W.,CAS Lanzhou Institute of Chemical Physics | Wang W.,University of Chinese Academy of Sciences | Wang A.,CAS Lanzhou Institute of Chemical Physics
Carbohydrate Polymers | Year: 2010

Grafting vinyl monomers onto natural polysaccharides and then compounding with inorganic nano-scale clays become a preferred method to derive superabsorbents because it afforded unique environmental and commercial advantages. In current work, a series of superabsorbent nanocomposites were prepared by radical solution polymerization of sodium carboxymethyl cellulose (CMC), partially neutralized acrylic acid (NaA) and attapulgite (APT) using ammonium persulfate (APS) as an initiator and N,N′-methylenebisacrylamide (MBA) as a crosslinker. Fourier transform infrared spectroscopy (FTIR) spectra proved that NaA was grafted onto CMC backbone and APT participated in polymerization. APT nanofibrils were retained in nanocomposite and uniformly dispersed in the CMC-g-PNaA matrix as shown by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscope (FESEM) analyses. The thermal stability and water absorption of the nanocomposites were improved due to the incorporation of APT. The water absorption and gel strength depends on the MBA concentration. The remarkable pH-sensitivity and time-dependent swelling behavior of the nanocomposite in aqueous solution of cetyltrimethylammonium bromide (CTAB) were observed and discussed. © 2010 Elsevier Ltd. All rights reserved.


Zhang J.,CAS Lanzhou Institute of Chemical Physics | Li B.,CAS Lanzhou Institute of Chemical Physics | Wu L.,CAS Lanzhou Institute of Chemical Physics | Wu L.,University of Chinese Academy of Sciences | Wang A.,CAS Lanzhou Institute of Chemical Physics
Chemical Communications | Year: 2013

This article presents a facile approach for the preparation of durable and robust superhydrophobic textiles by simply dip coating in a nanocomposite solution of fluoro-free organosilanes. The superhydrophobic textiles exhibit good water repellency and excellent mechanical, chemical and environmental stability. © 2013 The Royal Society of Chemistry.


Huang D.,CAS Lanzhou Institute of Chemical Physics | Huang D.,University of Chinese Academy of Sciences | Wang A.,CAS Lanzhou Institute of Chemical Physics
RSC Advances | Year: 2013

Multiwalled carbon nanotubes (MWCNTs) were regarded as ideal candidates for fillers in a polymer matrix due to their outstanding mechanical, electrical and thermal properties. A series of nanocomposite films were prepared by a solution casting method introducing chitosan (CS) treated MWCNTs into a poly (vinyl alcohol) (PVA) matrix. The nanocomposites were characterized by field emission scanning electron microscopy and Fourier Transform Infrared Spectroscopy. The results indicated that MWCNTs treated by chitosan dispersed well in the PVA matrix, and the tensile properties and water resistance of nanocomposites were improved greatly compared with neat PVA. This journal is © The Royal Society of Chemistry 2013.


Guo S.,CAS Changchun Institute of Applied Chemistry | Guo S.,University of Chinese Academy of Sciences | Guo S.,Brown University | Dong S.,CAS Changchun Institute of Applied Chemistry | Dong S.,University of Chinese Academy of Sciences
Journal of Materials Chemistry | Year: 2011

Graphene, a new material for which the Noble prize was won, has received increasing attention due to its unique physicochemical properties, such as a high surface area, excellent conductivity, a high mechanical strength, and good biocompatibility. In particular, in the last two years there has been explosive growth in studies relating to the use of graphene and its derivatives as enhanced materials or carriers for probes and recognition elements in the development of high-performance analytical devices. In this feature article, we will highlight recent important progress in the construction of graphene and its derivative-based high-performance analytical sensors. First, recent research efforts on the design of new electrochemical sensors, including amperometry, electrochemical luminescence (ECL), field-effect transistor (FET), electrochemical impedance, photoelectrochemical and surface plasmon resonance (SPR) electrochemical sensors are described. Then, we will move on to discuss more modish optical sensors, such as fluorescent, colorimetric and surface enhanced Raman spectroscopy (SERS) sensors. Finally, we conclude with a look at the future challenges and prospects of graphene and its derivative-related analytical devices. © 2011 The Royal Society of Chemistry.


Liu J.-J.,CAS Xishuangbanna Tropical Botanical Garden | Liu J.-J.,University of Chinese Academy of Sciences | Slik J.W.F.,University of Brunei Darussalam
Biological Conservation | Year: 2014

Deforestation and associated forest fragmentation are main drivers of species loss across the tropics. Many studies have focused on how fragment edge effect, size, isolation and shape, affect species persistence within landscapes. Little attention has been paid to the impact of the distribution of the fragments itself on the preservation of local species pools. Here we test the importance of the spatial distribution of remaining forest fragments, relative to other fragmentation effects, on tree species diversity, composition and rarity patterns within a tropical landscape converted to rubber plantations in southern Yunnan, China. We find that the remaining forest fragments are non-randomly distributed in the landscape, with most fragments located at higher elevations, steeper slopes and shade aspects. At the same time we find that most of the observed patterns in tree diversity, composition and rarity are explained by the location of the fragments within the landscape, with very little additional impact of other fragmentation effects, even though fragmentation started more than two decades ago. We conclude that during the initial stages of land use change, the protection of forest areas along the entire environmental gradient should be a prime focus for conservation efforts as it is at this stage that most tree species can be preserved in the landscape. We also stress the importance of small forest fragments for the conservation of tree species, especially because such fragments are usually located in sites with the highest deforestation rates. © 2014 Elsevier Ltd.


Liu W.,CAS Lanzhou Institute of Chemical Physics | Liu W.,University of Chinese Academy of Sciences | Yan X.,CAS Lanzhou Institute of Chemical Physics | Lang J.,CAS Lanzhou Institute of Chemical Physics | Xue Q.,CAS Lanzhou Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2012

Graphene nanosheets (GNSs)-ionic liquids (ILs) electrochemical system is of great interest as it shows excellent electrochemical properties for high performance supercapacitors. In this paper, the effects of concentration and temperature of ILs electrolyte on the electrochemical properties of a GNSs electrode are characterized by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy measurements (EIS) in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF 4)/ acetonitrile electrolyte. The results show that the internal resistance and the specific capacitance are strongly dependent on the variation of molar concentration of EMIMBF 4, and the GNSs electrode exhibits high specific capacitance (128.2 F g -1) and a wide potential window (2.3 V) in 2.0 M EMIMBF 4/acetonitrile electrolyte, indicating the excellent electrochemical performance. Moreover, the GNSs electrode has wide operating temperatures ranging from -20 °C to 60 °C with a potential window from -0.6 V to 1.5 V in the EMIMBF 4/acetonitrile electrolyte. The result also reveals a weak dependence of the supercapacitive performance of the GNSs electrode on the temperature of the EMIMBF 4/acetonitrile electrolyte. In addition, the specific capacitances have almost no decay after 1500 charge/discharge cycles in the above mentioned temperature region, demonstrating the good stability of the GNSs-ILs system in high-temperature and low-temperature environments. © 2012 The Royal Society of Chemistry.


Zhang Y.,Beijing Institute of Technology | Wang Z.,Beijing Institute of Technology | Zhou G.,University of Chinese Academy of Sciences
Energy Policy | Year: 2013

China is one of the major energy-consuming countries, and is under great pressure to promote energy saving and reduce domestic energy consumption. Employees constitute an important target group for energy saving. However, only a few research efforts have been paid to study what drives employee energy saving behavior in organizations. To fill this gap, drawing on norm activation model (NAM), we built a research model to study antecedents of employee electricity saving behavior in organizations. The model was empirically tested using survey data collected from office workers in Beijing, China. Results show that personal norm positively influences employee electricity saving behavior. Organizational electricity saving climate negatively moderates the effect of personal norm on electricity saving behavior. Awareness of consequences, ascription of responsibility, and organizational electricity saving climate positively influence personal norm. Furthermore, awareness of consequences positively influences ascription of responsibility. This paper contributes to the energy saving behavior literature by building a theoretical model of employee electricity saving behavior which is understudied in the current literature. Based on the empirical results, implications on how to promote employee electricity saving are discussed. © 2013 Elsevier Ltd.


Pan B.-Z.,CAS Xishuangbanna Tropical Botanical Garden | Pan B.-Z.,University of Chinese Academy of Sciences | Xu Z.-F.,CAS Xishuangbanna Tropical Botanical Garden
Journal of Plant Growth Regulation | Year: 2011

Jatropha curcas, a monoecious perennial biofuel shrub belonging to the family Euphorbiaceae, has few female flowers, which is one of the most important reasons for its poor seed yield. This study was undertaken to determine the effects of the plant growth regulator 6-benzyladenine (BA) on floral development and floral sex determination of J. curcas. Exogenous application of BA significantly increased the total number of flowers per inflorescence, reaching a 3.6-fold increase (from 215 to 784) at 160mg/l of BA. Furthermore, BA treatments induced bisexual flowers, which were not found in control inflorescences, and a substantial increase in the female-to-male flower ratio. Consequently, a 4.5-fold increase in fruit number and a 3.3-fold increase in final seed yield were observed in inflorescences treated with 160mg/L of BA, which resulted from the greater number of female flowers and the newly induced bisexual flowers in BA-treated inflorescences. This study indicates that the seed yield of J. curcas can be increased by manipulation of floral development and floral sex expression. © 2010 The Author(s).


Guo S.,CAS Changchun Institute of Applied Chemistry | Guo S.,University of Chinese Academy of Sciences | Guo S.,Brown University | Wang E.,CAS Changchun Institute of Applied Chemistry | Wang E.,University of Chinese Academy of Sciences
Nano Today | Year: 2011

Nobel metal nanomaterials (NMNs) with interesting physical and chemical properties are ideal building blocks for engineering and tailoring nanoscale structures for specific technological applications. Particularly, effectively controlling the size, shape, architecture, composition, hybrid and microstructure of NMNs plays an important role on revealing their new or enhanced functions and application potentials such as fuel cell and analytical sensors. This review article focuses on recent advances on controllable synthesis and fuel cell and sensing applications of NMNs. First, recent contributions on developing a wet-chemical approach for the controllable synthesis of noble metal nanomaterials with a rich variety of shapes, e.g. single-component Pt, Pd, Ag and Au nanomaterials, multi-component core/shell, intermetallic or alloyed nanomaterials, metal fluorescent nanoclusters and metal nanoparticles-based hybrid nanomaterials, are summarized. Then diversified approaches to different types of NMNs-based nanoelectrocatalysts with the aim to enhance their activity and durability for fuel cell reactions are outlined. The review next introduces some exciting push in the use of NMNs as enhanced materials or reporters or labels for developing new analytical sensors including electrochemical, colorimetric and fluorescent sensors. Finally, we conclude with a look at the future challenges and prospects of the development of NMNs. © 2011 Elsevier Ltd. All rights reserved.


Liu W.-W.,CAS Lanzhou Institute of Chemical Physics | Liu W.-W.,University of Chinese Academy of Sciences | Yan X.-B.,CAS Lanzhou Institute of Chemical Physics | Lang J.-W.,CAS Lanzhou Institute of Chemical Physics | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

There is currently a strong demand for energy storage devices which are cheap, light weight, flexible, and possess high power and energy densities to meet the various requirements of modern gadgets. Herein, we prepare a flexible and easily processed electrode via a simple "brush-coating and drying" process using everyday cotton cloth as the platform and a stable graphene oxide (GO) suspension as the ink. After such a simple manufacturing operation followed by annealing at 300 °C in argon atmosphere, the as-obtained graphene sheets (GNSs)-cotton cloth (CC) composite fabric exhibits good electrical conductivity, outstanding flexibility, and strong adhesion between GNSs and cotton fibers. Using this GNSs-CC composite fabric as the electrode material and pure CC as the separator, a home-made supercapacitor was fabricated. The supercapacitor shows the specific capacitance of 81.7 F g -1 (two-electrode system) in aqueous electrolyte, which is one of the highest values for GNSs-based supercapacitors. Moreover, the supercapacitor also exhibits satisfactory capacitance in ionic-liquid/organic electrolyte. An all-fabric supercapacitor was also fabricated using pure CC as separator and GNSs-CC composite fabric as electrode and current collector. Such a conductive GNSs-CC composite fabric may provide new design opportunities for wearable electronics and energy storage applications. © The Royal Society of Chemistry 2012.


Liu Q.,CAS Lanzhou Institute of Chemical Physics | Liu Q.,University of Chinese Academy of Sciences | Jin J.,CAS Lanzhou Institute of Chemical Physics | Jin J.,University of Chinese Academy of Sciences | Zhang J.,CAS Lanzhou Institute of Chemical Physics
ACS Applied Materials and Interfaces | Year: 2013

Here, the hybrid of NiCo2S4 nanoparticles grown on graphene in situ is first described as an effective bifunctional nonprecious electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the alkaline medium. NiCo2S4@N/S-rGO was synthesized by a one-pot solvothermal strategy using Co(OAc)2, Ni(OAc)2, thiourea, and graphene oxide as precursors and ethylene glycol as the dispersing agent; simultaneously, traces of nitrogen and sulfur were double-doped into the reduced graphene oxide (rGO) in the forms of pyrrolic-N, pyridinic-N, and thiophenic-S, which are often desirable for metal-free ORR catalysts. In comparison with commercial Pt/C catalyst, NiCo 2S4@N/S-rGO shows less reduction activity, much better durability, and superior methanol tolerance toward ORR in 0.1 M KOH; it reveals higher activity toward OER in both KOH electrolyte and phosphate buffer at pH 7.0. NiCo2S4@graphene demonstrated excellent overall bicatalytic performance, and importantly, it suggests a novel kind of promising nonprecious bifunctional catalyst in the related renewable energy devices. © 2013 American Chemical Society.


Li H.,CAS Institute of Psychology | Li H.,University of Chinese Academy of Sciences | Chan R.C.K.,CAS Institute of Psychology | Chan R.C.K.,University of Hong Kong | And 2 more authors.
Schizophrenia Bulletin | Year: 2010

Background: People with schizophrenia have difficulty with emotion perception. Functional imaging studies indicate regional brain activation abnormalities in patients with schizophrenia when processing facial emotion. However, findings have not been entirely consistent across different studies. Methods: Activation likelihood estimation (ALE) meta-analyses were conducted to examine brain activation during facial emotion processing in patients with schizophrenia, controls, and patients compared with controls. Secondary meta-analyses were performed to assess the contribution of task design and illness chronicity to the results reported. Results: When processing facial expressions of emotions, both patients with schizophrenia and healthy controls activated the bilateral amygdala and right fusiform gyri. However, the extent of activation in these regions was generally much more limited in the schizophrenia samples. When directly compared with controls, the extent of activation in bilateral amygdala, parahippocampal gyrus and fusiform gyrus, right superior frontal gyrus, and lentiform nucleus was significantly less in patients. Patients with schizophrenia, but not controls, activated the left insula. A relative failure to recruit the amygdala in patients occurred regardless of whether the task design was explicit or implicit, while differences in fusiform activation were evident in explicit, not implicit, tasks. Restricting the analysis to patients with chronic illness did not substantially change the results. Conclusions: A marked underrecruitment of the amygdala, accompanied by a substantial limitation in activation throughout a ventral temporal-basal ganglia-prefrontal cortex "social brain" system may be central to the difficulties patients experience when processing facial emotion. © The Author 2009.


Cui E.,CAS Lanzhou Institute of Chemical Physics | Cui E.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
Journal of Physical Chemistry C | Year: 2013

We reported the results of the modulation of photogenerated electrons transfer and photocatalytic hydrogen evolution behaviors of Pt/TiO2 photocatalyst via controlling surface potential energy on a selectively exposed Pt facet for a highly efficient photocatalytic hydrogen generation from water. By photosensitization using Eosin Y as an antenna molecule, distinct differences in photocatalytic hydrogen evolution performances over Pt/TiO2 with different exposed facets ({100}, {100/111}, and {111}) of Pt under visible light irradiation were observed. Pt{111}/TiO2 photocatalyst exhibited a much higher photocatalytic hydrogen generation activity than those of Pt{100}/TiO2 and Pt{100/111}/TiO2. As evidenced by photoluminescence spectra, photoelectrochemical characterizations, electrochemical impedance spectra (EIS) measurements, and Mott-Schottky measurements, Pt nanoparticles with exposed {111} facets were more effective in trapping the electrons from the conduction band of TiO2 than that of {100} facets due to their higher Fermi level of {111} facets. In addition, Pt{111}/TiO2 exhibited much lower apparent activation energy for hydrogen generation than those of other samples because the fraction of Pt atoms located on edges and corners on Pt{111} nanoparticles was higher than that on Pt{100} nanoparticles. Therefore, Pt{111}/TiO2 can provide more reaction sites for water reduction. In addition, Pt{111}/TiO2 exhibits much lower apparent activation energy or hydrogen generation than those of other samples because this catalyst can provide more reaction sites for water reduction. The formation of hydrogen via recombination between chemisorbed H atoms is more likely to occur over Pt{111} facets because of the reasonable transition state geometry of chemisorbed H on Pt{111} facets. This study discloses the facet-dependent effect of noble-metal cocatalyst on semiconductors in photocatalytic water reduction and will give an insight into design and synthesis of high-efficient metal/semiconductor hybrid photocatalysts. © 2013 American Chemical Society.


Zhou L.-J.,CAS Fujian Institute of Research on the Structure of Matter | Zhou L.-J.,University of Chinese Academy of Sciences | Zhang Y.-F.,Fuzhou University | Wu L.-M.,CAS Fujian Institute of Research on the Structure of Matter
Nano Letters | Year: 2013

In excitonic solar cells (XSC), power conversion efficiency (PCE) depends critically on the interface band alignment between donor and acceptor materials. Graphene or silicene is not suitable for donor materials due to their semimetallic features (zero band gaps); it is therefore highly desired to open an energy gap in graphene or silicene to extend their application in optoelectronic devices, especially in photovoltaics. In this paper, based on the global particle-swarm optimization algorithm and the density functional theory methods, we predict a novel SiC2 siligraphene (g-SiC2) with a direct band gap of 1.09 eV showing infinite planar geometry, in which Si and C atoms adopt sp2 hybridization and C atoms form delocalized 4 C-domains that are periodically separated by Si atoms. Such a g-SiC2 siligraphene (with a global minimum of energy) is 0.41 eV/atom lower and thermally stabler than the isomeric pt-SiC2 silagraphene containing planar 4-fold coordinated silicon (3000 K vs 1000 K). Interestingly, the derivative (n, 0), (n, n) nanotubes (with diameters greater than 8.0 Å) have band gaps about 1.09 eV, which are independent of the chirality and diameter. Besides, a series of g-SiC2/GaN bilayer and g-SiC 2 nanotube/ZnO monolayer XSCs have been proposed, which exhibit considerably high PCEs in the range of 12-20%. © 2013 American Chemical Society.


Jiang Y.,CAS Xishuangbanna Tropical Botanical Garden | Jiang Y.,University of Chinese Academy of Sciences | Liang G.,CAS Xishuangbanna Tropical Botanical Garden | Yu D.,CAS Xishuangbanna Tropical Botanical Garden
Molecular Plant | Year: 2012

Drought is one of the most serious environmental factors that limit the productivity of agricultural crops worldwide. However, the mechanism underlying drought tolerance in plants is unclear. WRKY transcription factors are known to function in adaptation to abiotic stresses. By screening a pool of WRKY-associated T-DNA insertion mutants, we isolated a gain-of-function mutant, acquired drought tolerance (adt), showing improved drought tolerance. Under drought stress conditions, adt accumulated higher levels of ABA than wild-type plants. Stomatal aperture analysis indicated that adt was more sensitive to ABA than wild-type plants. Molecular genetic analysis revealed that a T-DNA insertion in adt led to activated expression of a WRKY gene that encodes the WRKR57 protein. Constitutive expression of WRKY57 also conferred similar drought tolerance. Consistently with the high ABA content and enhanced drought tolerance, three stress-responsive genes (RD29A, NCED3, and ABA3) were up-regulated in adt. ChIP assays demonstrated that WRKY57 can directly bind the W-box of RD29A and NCED3 promoter sequences. In addition, during ABA treatment, seed germination and early seedling growth of adt were inhibited, whereas, under high osmotic conditions, adt showed a higher seed germination frequency. In summary, our results suggested that the activated expression of WRKY57 improved drought tolerance of Arabidopsis by elevation of ABA levels. Establishment of the functions of WRKY57 will enable improvement of plant drought tolerance through gene manipulation approaches. © 2012 The Author.


Liang G.,CAS Xishuangbanna Tropical Botanical Garden | He H.,CAS Xishuangbanna Tropical Botanical Garden | He H.,University of Chinese Academy of Sciences | Yu D.,CAS Xishuangbanna Tropical Botanical Garden
PLoS ONE | Year: 2012

microRNAs (miRNAs) are a class of negative regulators that take part in many processes such as growth and development, stress responses, and metabolism in plants. Recently, miRNAs were shown to function in plant nutrient metabolism. Moreover, several miRNAs were identified in the response to nitrogen (N) deficiency. To investigate the functions of other miRNAs in N deficiency, deep sequencing technology was used to detect the expression of small RNAs under N-sufficient and -deficient conditions. The results showed that members from the same miRNA families displayed differential expression in response to N deficiency. Upon N starvation, the expression of miR169, miR171, miR395, miR397, miR398, miR399, miR408, miR827, and miR857 was repressed, whereas those of miR160, miR780, miR826, miR842, and miR846 were induced. miR826, a newly identified N-starvation-induced miRNA, was found to target the AOP2 gene. Among these N-starvation-responsive miRNAs, several were involved in cross-talk among responses to different nutrient (N, P, S, Cu) deficiencies. miR160, miR167, and miR171 could be responsible for the development of Arabidopsis root systems under N-starvation conditions. In addition, twenty novel miRNAs were identified and nine of them were significantly responsive to N-starvation. This study represents comprehensive expression profiling of N-starvation-responsive miRNAs and advances our understanding of the regulation of N homeostasis mediated by miRNAs. © 2012 Liang et al.


Liu Q.,CAS Lanzhou Institute of Chemical Physics | Liu Q.,University of Chinese Academy of Sciences | Zhang J.,CAS Lanzhou Institute of Chemical Physics
Langmuir | Year: 2013

Graphitic carbon nitride (g-C3N4) polymer was doped with cobalt species and supported on a similar sp2 structure graphene, to form a novel nitrogen-metal macrocyclic catalyst for the oxygen reduction reaction (ORR) in alkaline fuel cells. The structural characterizations confirmed the formation of Co-N bonds and the close electron coupling between Co-g-C3N4 and graphene sheets. The electrocatalytic measurements demonstrated Co-g-C3N 4-catalyzed reduction of oxygen mainly in a four electron pathway. The improvement of ORR activity is closely related to the abundant accessible Co-Nx active sites and fast charge transfer at the interfaces of Co-g-C3N4/graphene. Also, Co-g-C3N 4@graphene exhibited comparable ORR activity, better durability, and methanol tolerance ability in comparison to Pt/C, and bodes well for a promising non-noble cathode catalyst for the application of direct methanol fuel cells. The chemical doping strategy in this work would be helpful to improve other present catalysts for fuel cell applications. © 2013 American Chemical Society.


Chen F.-F.,CAS Lanzhou Institute of Chemical Physics | Chen F.-F.,University of Chinese Academy of Sciences | Xie X.-Y.,CAS Lanzhou Institute of Chemical Physics | Xie X.-Y.,University of Chinese Academy of Sciences | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Journal of Chromatography A | Year: 2013

The magnetic molecularly imprinted polymers (MMIPs) for resveratrol were prepared by using surface molecular imprinting technique with a super paramagnetic core-shell nanoparticle as a supporter. Rhapontigenin, which is the analogues of resveratrol, was selected as dummy template molecules to avoid the leakage of trace amount of resveratrol. Acrylamide and ethylene glycol dimethacrylate were chosen as functional monomers and cross-linker, respectively. The obtained MMIPs were characterized by using scanning electron microscopy, Fourier transform infrared spectrum, X-ray diffraction and vibrating sample magnetometer. High performance liquid chromatography was used to analyze the target analytes. The resulting MMIPs exhibited high saturation magnetization of 53.14emug-1 leading to the fast separation. The adsorption test showed that the MMIPs had high adsorption capacity for resveratrol and contained homogeneous binding sites. The MMIPs were employed as adsorbent of solid phase extraction for determination of resveratrol in real wine samples, and the recoveries of spiked samples ranged from 79.3% to 90.6% with the limit of detection of 4.42ngmL-1. The prepared MMIPs could be employed to selectively pre-concentrate and determine resveratrol from wine samples. © 2013 Elsevier B.V.


Liang G.,CAS Xishuangbanna Tropical Botanical Garden | Liang G.,University of Chinese Academy of Sciences | Yang F.,CAS Xishuangbanna Tropical Botanical Garden | Yu D.,CAS Xishuangbanna Tropical Botanical Garden
Plant Journal | Year: 2010

Summary Sulfur is a macronutrient that is necessary for plant growth and development. Sulfate, a major source of sulfur, is taken up by plant roots and transported into various tissues for assimilation. During sulfate limitation, expression of miR395 is significantly up-regulated. miR395 targets two families of genes, ATP sulfurylases (encoded by APS genes) and sulfate transporter 2;1 (SULTR2;1, also called AST68), both of which are involved in the sulfate metabolism pathway. Their transcripts are suppressed strongly in miR395-over-expressing transgenic Arabidopsis, which over-accumulates sulfate in the shoot but not in the root. APS1 knockdown mutants accumulate twice as much sulfate as the wild-type. By constructing APS4-RNAi transgenic plants, we found that silencing the APS4 gene also results in over-accumulation of sulfate. Even though miR395-over-expressing transgenic plants over-accumulate sulfate in the shoot, they display sulfur deficiency symptoms. Additionally, the distribution of sulfate from older to younger leaves is impaired in miR395-over-expressing plants, similar to a SULTR2;1 loss-of-function mutant. The aps1-1 sultr2;1 APS4-RNAi triply repressed mutants phenocopied miR395-over-expressing plants. Our research showed that miR395 is involved in the regulation of sulfate accumulation and allocation by targeting APS genes and SULTR2;1, respectively. © 2010 Blackwell Publishing Ltd.


Chen S.,CAS Lanzhou Institute of Chemical Physics | Chen S.,University of Chinese Academy of Sciences | Wang Q.,CAS Lanzhou Institute of Chemical Physics | Wang T.,CAS Lanzhou Institute of Chemical Physics
Materials and Design | Year: 2012

A series of castor oil-based polyurethane (PU)/epoxy resin (EP)-graft interpenetrating polymer network (IPN) composites loaded with multi-walled carbon nanotubes (CNTs) were prepared. The damping properties, thermal stability, tensile and impact strengths, as well as fractured surfaces of the CNTs modified IPN composites were studied systematically. Results revealed that the incorporation of CNTs can improve the damping capacity especially when the CNTs content was 0.1%, though the thermal decomposition temperature decreased slightly. The storage modulus was also increased with the addition of CNTs. The mechanical properties of the modified polymer composites were improve. The tensile strength of the polymer composites increase by more than 30% compared to the matrix, when the CNTs contents were 0.1% and 0.7%. When the CNTs content was 0.3%, the impact strength of the modified composites increased by ca. 54% compared to the polymer matrix. It is expected that the modified composites may be used as structural damping materials. © 2012 Elsevier Ltd.


Zhao J.,CAS Lanzhou Institute of Chemical Physics | Zhao J.,University of Chinese Academy of Sciences | Li P.,CAS Lanzhou Institute of Chemical Physics | Xia C.,CAS Lanzhou Institute of Chemical Physics | Li F.,CAS Lanzhou Institute of Chemical Physics
Chemical Communications | Year: 2014

The KI-catalyzed N-acylation of azoles via direct oxidative coupling of C-H and N-H bonds has been developed. It could be smoothly scaled up to gram synthesis of acyl azoles. The reaction occurred by the coupling of acyl radicals and azoles to form the acyl azole radical anion, followed by its further oxidation. This journal is © the Partner Organisations 2014.


Xu L.,CAS Lanzhou Institute of Chemical Physics | Xu L.,University of Chinese Academy of Sciences | Song H.,CAS Lanzhou Institute of Chemical Physics | Chou L.,CAS Lanzhou Institute of Chemical Physics
ACS Catalysis | Year: 2012

Ordered mesoporous tricompound NiO-CaO-Al2O3 composite oxides with various Ca content were first designed and facilely synthesized via a one-pot, evaporation-induced, self-assembly (EISA) strategy. The obtained mesoporous materials with advantageous textural properties and superior thermal stabilities were investigated as the catalysts for the carbon dioxide reforming of methane reaction. These mesoporous catalysts entirely showed high catalytic activities as well as long catalytic stabilities toward this reaction. The improved catalytic activities were suggested to be closely associated with the advantageous structural properties, such as large specific surface areas; big pore volumes; and uniform pore sizes, which could provide sufficient "accessible" active centers for the gaseous reactants. In addition, the "confinement effect" of the mesoporous matrixes contributed to stabilizing the Ni active sites during the processes of reduction and reaction, accounting for the long lifetime stabilities of these mesoporous catalysts. The modification of Ca played dual roles in promoting the catalytic activities and suppressing the carbon deposition by enhancing the chemisorption of the CO2. Generally, the ordered mesoporous NiO-CaO-Al 2O3 composite oxides could be considered as promising catalysts for the carbon dioxide reforming of methane reaction. © 2012 American Chemical Society.


Hu Y.,CAS Xishuangbanna Tropical Botanical Garden | Hu Y.,University of Chinese Academy of Sciences | Dong Q.,CAS Xishuangbanna Tropical Botanical Garden | Yu D.,CAS Xishuangbanna Tropical Botanical Garden
Plant Science | Year: 2012

The WRKY transcription factors are involved in plant resistance against both biotrophic and necrotrophic pathogens. Arabidopsis WRKY46 is specifically induced by salicylic acid (SA) and biotrophic pathogen Pseudomonas syringae infection. To determine its possible roles in plant defense and elucidate potential functional redundancy with structurally related WRKY70 and WRKY53, we examined loss-of-function T-DNA insertion single, double and triple mutants, as well as gain-of-function transgenic WRKY46 over-expressing plants in response to P. syringae. WRKY46 over-expressing plants were more resistant to P. syringae. In contrast, pathogen-infected wrky46wrky70, wrky46wrky53 double mutants and wrky46wrky70wrky53 triple mutants showed increased susceptibility to this pathogen, with increased bacterial growth and more severe disease symptoms. The contrasting responses of gain-of-function plants and loss-of-function mutants were correlated with increased or reduced expression of defense-related PR1 gene. Expression studies of WRKY46, WRKY70, and WRKY53 in various defense-signaling mutants suggested that they are partially involved in SA-signaling pathway. In addition, our findings demonstrated negative cross-regulation among these three genes. These results indicate that WRKY46, WRKY70, and WRKY53 positively regulate basal resistance to P. syringae; and that they play overlapping and synergetic roles in plant basal defense. © 2011 Elsevier Ireland Ltd.


Kong C.,CAS Lanzhou Institute of Chemical Physics | Kong C.,University of Chinese Academy of Sciences | Min S.,CAS Lanzhou Institute of Chemical Physics | Min S.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
Chemical Communications | Year: 2014

The hydrogen evolution activity of Pt was remarkably enhanced by the addition of Sn. The amount of H2 produced in 90 min over the platinum-tin alloy decorated graphene photocatalyst was 1.97 times higher than that of Pt-graphene, and the highest apparent quantum efficiency reached 87.2% at 430 nm. © 2014 the Partner Organisations.


Song D.,CAS Lanzhou Institute of Chemical Physics | Song D.,University of Chinese Academy of Sciences | Chen J.,CAS Lanzhou Institute of Chemical Physics
Journal of Chemical and Engineering Data | Year: 2014

The density and viscosity of binary ionic liquid mixtures with a common anion, 1-ethyl-3-methylimidazolium tetrafluoroborate + 1-propyl-3- methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate + 1-propyl-3-methylimidazolium tetrafluoroborate, and 1-propyl-3-methylimidazolium tetrafluoroborate + 1-hexyl-3-methylimidazolium tetrafluoroborate were determined in the temperature range of (298.15 to 343.15) K. The excess molar volumes were calculated and correlated by Redlich-Kister polynomial expansions. The viscosities for pure ionic liquids were analyzed by means of the Vogel-Tammann-Fulcher equation, and ideal mixing rules were applied for the mixtures. © 2014 American Chemical Society.


Yang Y.,CAS Lanzhou Institute of Chemical Physics | Yang Y.,University of Chinese Academy of Sciences | Chen J.,CAS Lanzhou Institute of Chemical Physics | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Talanta | Year: 2012

Carbon nanotube-reinforced hollow fiber solid-phase microextraction (CNTs-HF-SPME) combined with high-performance liquid chromatography (HPLC) was used to extract and determine diethylstilbestrol (DES) in milk products. Wall pores of the hollow fiber were filled with multi-walled carbon nanotubes (MWCNTs) using sol-gel technology. In the proposed method, DES was selectively extracted by MWCNTs, desorbed to methanol, and analyzed by HPLC. The parameters affecting the efficiency of CNTs-HFSPME, such as the length of the hollow fiber, extraction and desorption times, extraction temperature, stirring rate, pH of the sample solution, and the amount of organic solvent and salt in the sample solution, were investigated and optimized. Under the optimized extraction conditions, the method showed good linearity (24-960 μg L-1), a low method detection limit (MDL, 5.1 μg L-1), and good recoveries at four different concentrations. It was proven to be simple, rapid, sensitive, and solvent free for the analysis of DES in dairy products. © 2012 Elsevier B.V. All rights reserved.


Wu C.-M.,University of Chinese Academy of Sciences | Zhao G.,University of Hong Kong
Lithos | Year: 2011

The various existing garnet-orthopyroxene geobarometers calibrated based on the Al2O3 or Cr2O3 components in orthopyroxene buffered by coexisting garnet for mantle xenoliths, abbreviated as Al2O3-barometer and Cr2O3-barometer, respectively, have been extensively studied, to test their precision by applying them to phase equilibrium experimental data, and to evaluate their validity by applying them to natural pyrolites. The Cr2O3-barometers failed in reconstructing the experimental pressures due to imprecise description of activities of garnet and orthopyroxene end members. Several of the Al2O3-barometers showed perfect ability in reproducing the experimental pressures and successfully discerned the garnet-facies and garnet-spinel transition facies lherzolites as well as the graphite- or diamond-bearing mantle xenoliths. It is recommended that pressure and temperature estimation of mantle xenoliths may be best determined simultaneously by combining the garnet-orthopyroxene barometer and the two-pyroxene thermometer of Taylor (1998). Orthopyroxenes containing Al2O3 contents of less than 0.37wt.% should not be used in the pressure estimation in order to avoid significant P-T errors propagated from analytical errors. © 2011 Elsevier B.V.


Min S.,CAS Lanzhou Institute of Chemical Physics | Min S.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2012

In this work, a highly efficient and stable photocatalytic H 2 evolution catalyst was constructed on Pt deposited graphene sheets cosensitized by Eosin Y (EY) and Rose Bengal (RB). Under two-beam monochromic light irradiation (520 and 550 nm), a high quantum yield (QY) up to 37.3% has been achieved owing to maximum utilization of incident visible light. As a result of the excellent electron transport properties of graphene, it can greatly facilitate the forward electron transfer from photoexcited dye molecules to Pt catalyst and suppress back electron transfer, which significantly enhances photocatalytic efficiency for H 2 evolution. This efficient cosensitization strategy is also effective in enhancing H 2 evolution efficiencies of dye sensitized TiO 2 and multiwall carbon nanotubes (MWCNTs). © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Min S.,CAS Lanzhou Institute of Chemical Physics | Min S.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2013

Directional electron transfer and effective charge separation facilitated by graphene sheets have provided an inspiring approach to enhance the efficiencies of photoelectric conversion and photocatalysis. Herein, we demonstrated the feasibility of constructing a highperformance of the dye-sensitized H2 evolution system using dispersible graphene sheets as both efficient electron transfer carrier and catalyst scaffold. Among the xanthene dyes sensitized H2 evolution catalysts in this study, photocatalyst of Rose Bengal (RB) sensitized graphene decorated with Pt is the most active one and exhibits the highest apparent quantum efficiency (AQE) of 18.5% at wavelength of 550 nm and rather long-term stability for H2 evolution. Dispersible graphene sheets can not only capture electrons from the excited dye and then transfer them to the decorated catalysts efficiently for improving charge separation with a small energy loss, but also afford large interfaces for highly dispersing catalyst nanoparticles with more active sites, thereby significantly enhancing the H2 evolution efficiency than graphite oxide (GO) and multiwall carbon nanotubes (MWCNTs). This work proposes a potential strategy to develop efficient photocatalytic systems for solar-energy-conversion and provides a new insight into mechanistic study of photoinduced electron transfer by effective synergetic combination of dispersible graphene sheets with an efficient dye and a H2 evolution catalyst. Copyright © 2012, Hydrogen Energy Publications, LLC.


Wei Q.,CAS Lanzhou Institute of Chemical Physics | Wei Q.,University of Chinese Academy of Sciences | Cai M.,CAS Lanzhou Institute of Chemical Physics | Zhou F.,CAS Lanzhou Institute of Chemical Physics | Liu W.,CAS Lanzhou Institute of Chemical Physics
Macromolecules | Year: 2013

We present a paradigm that dramatically tunes friction from superior lubrication (μ ∼ 10-3) to ultrahigh friction (μ > 1) using responsive polyelectrolyte brushes. The tunable friction is based on counterion-driven interactions in polyelectrolyte brushes that can be simply achieved by exchanging the counterions. We systematically investigated the effects of opposite counterions of different types on the friction properties of polyanionic, polycationic, and polyzwitterionic brushes. For cationic brushes with quaternary ammonium groups, the friction coefficient was progressively tuned from ∼10-3 to ∼100 according to the counterions series Cl- < ClO4 - < PF 6 - < TFSI-. The friction of anionic brushes can be tuned by oppositely charged surfactants (tetraalkylammonium) with different length of hydrophobic tails, multivalent metal ions, and protons. The friction increase of cationic brushes is due to the dehydration and the collapse of polyelectrolyte chains induced by ion-pairing interactions. For anionic brushes, the friction increased with the length of hydrophobic tails of surfactants, which resulted from hydrophobicity induced electrostatic interaction among surfactants and polymer chains. The anionic brushes with the carboxylate and the sulfonate side groups revealed different friction responses, which is owing to the carboxylate groups getting stronger specific interaction with the quaternary ammonium and thus with the multivalent metal ions as well. The mechanism of tuning friction was finally concluded; that is, highly hydrated and swelling polymer brushes show superior lubrication, partially collapsed polymer chains have moderate lubrication, and completely dehydrated and collapsed conformation loses lubricating capability. © 2013 American Chemical Society.


Li B.,CAS Lanzhou Institute of Chemical Physics | Li B.,University of Chinese Academy of Sciences | Lv G.-X.,CAS Lanzhou Institute of Chemical Physics
Journal of Molecular Catalysis | Year: 2013

The cosensitized effects of TiO2 by various dyes were investigated using photocatalytic water reduction for hydrogen production as a model reaction. The results showed that there was a profound cosensitization effect when Eosin Y (EY) and Rose Bengal (RB) were used as cosensitizer, while the combination of Ru(bipy)3Cl2 either with EY or RB did not show any cosensitization effects for hydrogen production. For EY/RB cosensitized systems, the UV-vis absorption spectra and fluorescence spectrum revealed that the remarkable cosensitization effect in EY/RB systems originated from not only the enhanced light absorption efficiency, but also the effective Förster resonant energy transfer (FRET) between two dyes, which could effectively reduce the energy loss due to the fluorescence quenching of excited state dyes, and enhance the photocatalytic efficiency of hydrogen production. This conclusion was confirmed by the transient photocurrent and monochromic light experiments. Our results also showed that the Ru/EY and Ru/RB cosensitized systems only exhibited photoreactivity for hydrogen production in the presence of methyl viologen (MV2+) as electron transfer relay. Under optimal conditions (λ≥420 nm), the apparent quantum yield (AQY) of hydrogen production for EY/RB cosensitized systems was 36.3% and 215.4% higher than that of single EY and RB sensitized systems, respectively.


Chen F.-F.,CAS Lanzhou Institute of Chemical Physics | Chen F.-F.,University of Chinese Academy of Sciences | Wang R.,CAS Lanzhou Institute of Chemical Physics | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Talanta | Year: 2012

Molecular imprinted polymers (MIPs) were prepared by thermal polymerization using a non-covalent molecularly imprinting strategy with kirenol as the template, acrylamide (AM) as the functional monomer and ethylene glycol dimethacrylamide (EGDMA) as the cross-linker in the porogen of tetrahydrofuran (THF). The synthesized MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). Its molecular recognition property was investigated by UV spectrogram. High-pressure liquid chromatography (HPLC) was used for analysis of target analytes. The polymers were evaluated further by batch rebinding experiments, and from the derived isotherms their binding capacity and binding strength were determined. Then the selectivity of the MIPs was checked toward the selected structurally related compounds and the recognition coefficients for kirenol, darutigenol, and ent-2-oxo-15, 16, 19-trihydroxypimar-8(14)-ene (TD) were 2.47, 3.43 and 3.40, respectively. The properties of MIPs for SPE were also evaluated. The results obtained demonstrate that the good imprinting effect and the excellent selectivity of MIPs were obtained. The optimized molecular imprinted SPE procedure was applied to extract kirenol directly from the extracts of the aerial part of Siegesbeckia pubescens herb. A selective extraction of kirenol from traditional Chinese medicine (TCM) was achieved with extraction yield of 80.9%. © 2012 Elsevier B.V. All rights reserved.


Feng J.,CAS Lanzhou Institute of Chemical Physics | Qiu H.,CAS Lanzhou Institute of Chemical Physics | Liu X.,CAS Lanzhou Institute of Chemical Physics | Jiang S.,CAS Lanzhou Institute of Chemical Physics | Feng J.,University of Chinese Academy of Sciences
TrAC - Trends in Analytical Chemistry | Year: 2013

•A review of novel SPME fibers with metal wires as supporting substrates.•Novel SPME fibers prepared by physical, chemical and electrochemical methods.•Lifetimes, desorption conditions and analytical performances of SPME fibers compared.•Novel SPME fibers applied in environmental, food, biological and medicinal analysis. This article gives a brief overview of the most relevant examples of solid-phase microextraction (SPME) fibers with metal wires as substrates, mainly concerning different preparation strategies including physical coating, chemical bonding and some other preparation techniques, which involved various sorbent materials (e.g., polymers, nanomaterials, mesoporous materials, metal-organic frameworks, and ionic liquids). © 2013 Elsevier Ltd.


Zhang H.-F.,CAS Lanzhou Institute of Chemical Physics | Zhang H.-F.,University of Chinese Academy of Sciences | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Analytica Chimica Acta | Year: 2012

A magnetic carbon nanomaterial for Fe 3O 4 enclosure hydroxylated multi-walled carbon nanotubes (Fe 3O 4-EC-MWCNTs-OH) was prepared by the aggregating effect of Fe 3O 4 nanoparticle on MWCNTs-OH, and combined with high-performance liquid chromatography (HPLC)/diode array detection (DAD) to determine the aconitines (aconitine, hypaconitine and mesaconitine) in human serum samples. Compared with other extraction modes investigated in experiment, Fe 3O 4-EC-MWCNTs-OH sorbents showed a good affinity to target analytes. Some important parameters that could influence extraction efficiency of aconitines, including the extraction mode, amounts of Fe 3O 4-EC-MWCNTs-OH, pH of sample solution, extraction time, desorption solvent and desorption time, were optimized. Under optimal conditions, the recoveries of spiked serum samples were between 98.0% and 103.0%; relative standard deviations (RSDs) ranged from 0.9% to 6.2%. The correlation coefficients varied from 0.9996 to 0.9998. The limits of detection ranged from 3.1ngmL -1 to 4.1ngmL -1 at a signal-to-noise ratio of 3. The experimental results showed that the proposed method was feasible for the analysis of aconitines in serum samples. © 2012 Elsevier B.V.


Song X.-Y.,CAS Lanzhou Institute of Chemical Physics | Song X.-Y.,University of Chinese Academy of Sciences | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics | Chen J.,CAS Lanzhou Institute of Chemical Physics
Food Chemistry | Year: 2013

An effective and sensitive method to determinate five carbamate pesticides in apples was developed by using carbon nanotubes-reinforced hollow fibre solid-phase microextraction (CNTs-HF-SPME) combined with high performance liquid chromatography-photodiode array detection (HPLC-DAD). The CNTs were dispersed in water via adding surfactant, and then were held in the pores of HF supported by capillary forces and sonification. The SPME device, which was wetted with 1-octanol, was placed in a stirred apple samples to extract target analytes. After extraction, analytes were desorbed and analyzed using HPLC-DAD. Under the optimized extraction conditions, the enrichment factors were achieved in the range from 49 to 308 with good inter-fibre repeatability and batch-to-batch reproducibility, while good linearity ranges and recoveries were obtained. The limits of detection ranged from 0.09 to 6.00 ng/g. Therefore, the results demonstrated that this novel method was an efficient pretreatment and enrichment procedure for the determination of trace carbamate pesticides in apples. © 2013 Elsevier Ltd. All rights reserved.


Xu L.,CAS Lanzhou Institute of Chemical Physics | Xu L.,University of Chinese Academy of Sciences | Song H.,CAS Lanzhou Institute of Chemical Physics | Chou L.,CAS Lanzhou Institute of Chemical Physics
Applied Catalysis B: Environmental | Year: 2011

Ordered mesoporous NiO-MgO-Al2O3 composite oxides with various Ni and Mg content were facilely synthesized via one pot evaporation induced self-assembly (EISA) strategy. These mesoporous materials with large specific surface areas, big pore volumes, uniform pore sizes and superior thermal stability were investigated as the catalysts for the carbon dioxide reforming of methane reaction. These materials performed high catalytic activity as well as long stability. The improved catalytic performances were suggested to be closely associated with both the amount of " accessible" active centers for the reactants owing to their advantageous structural properties and the stabilized Ni nanoparticles by mesoporous framework matrix due to the " confinement effect" of the mesopores. Besides, the role of the MgO basic modifier was also studied. It was observed that only moderate amount of the Mg containing (2M%) could greatly promote the catalytic performances. The stabilized Ni nanoparticles as well as doped MgO had reinforced capacity of resistance to coke, accounting for no deactivation after 100h long-term stability test at 700°C. Therefore, the ordered mesoporous NiO-MgO-Al2O3 composite oxides promised a series of novel and stable catalyst candidates for carbon dioxide reforming of methane reaction. © 2011 Elsevier B.V.


Tao F.,CAS Lanzhou Institute of Chemical Physics | Tao F.,University of Chinese Academy of Sciences | Song H.,CAS Lanzhou Institute of Chemical Physics | Chou L.,CAS Lanzhou Institute of Chemical Physics
Bioresource Technology | Year: 2011

Influence of acidity and structure of ionic liquids on microcrystalline cellulose (MCC) hydrolysis was investigated. MnCl2-containing ionic liquids (ILs) were efficient catalysts and achieved MCC conversion rates of 91.2% and selectivities for 5-hydroxymethyl furfural (HMF), furfural and levulinic acid (LA) of 45.7%, 26.2% and 10.5%, respectively. X-ray diffractometry indicated that catalytic hydrolysis of MCC in ionic liquids resulted in the changes to MCC crystallinity and transformation of cellulose I into cellulose II. SO3H-functionalized ionic liquids showed higher activities than non-functionalized ILs. The simplicity of the chemical transformation of cellulose provides a new approach for the use this polymer as raw material for renewable energy and chemical industries. © 2011.


Hu Y.,CAS Xishuangbanna Tropical Botanical Garden | Hu Y.,University of Chinese Academy of Sciences | Jiang L.,CAS Xishuangbanna Tropical Botanical Garden | Jiang L.,University of Chinese Academy of Sciences | And 2 more authors.
Plant Cell | Year: 2013

The INDUCER OF CBF EXPRESSION (ICE)-C-REPEAT BINDING FACTOR/DRE BINDING FACTOR1 (CBF/DREB1) transcriptional pathway plays a critical role in modulating cold stress responses in Arabidopsis thaliana. Dissecting crucial upstream regulatory signals or components of the ICE-CBF/DREB1 cascade will enhance our understanding of plant cold-tolerance mechanisms. Here, we show that jasmonate positively regulates plant responses to freezing stress in Arabidopsis. Exogenous application of jasmonate significantly enhanced plant freezing tolerance with or without cold acclimation. By contrast, blocking endogenous jasmonate biosynthesis and signaling rendered plants hypersensitive to freezing stress. Consistent with the positive role of jasmonate in freezing stress, production of endogenous jasmonate was triggered by cold treatment. In addition, cold induction of genes acting in the CBF/DREB1 signaling pathway was upregulated by jasmonate. Further investigation revealed that several JASMONATE ZIM-DOMAIN (JAZ) proteins, the repressors of jasmonate signaling, physically interact with ICE1 and ICE2 transcription factors. JAZ1 and JAZ4 repress the transcriptional function of ICE1, thereby attenuating the expression of its regulon. Consistent with this, overexpression of JAZ1 or JAZ4 represses freezing stress responses of Arabidopsis. Taken together, our study provides evidence that jasmonate functions as a critical upstream signal of the ICE-CBF/DREB1 pathway to positively regulate Arabidopsis freezing tolerance. © American Society of Plant Biologists. All rights reserved.


Li Z.,CAS Lanzhou Institute of Chemical Physics | Li Z.,University of Chinese Academy of Sciences | Liu J.,CAS Lanzhou Institute of Chemical Physics | Xia C.,CAS Lanzhou Institute of Chemical Physics | And 2 more authors.
ACS Catalysis | Year: 2013

N-functionalized ordered mesoporous carbons could be readily obtained by post-synthesis treatment with nitrogen containing molecules to achieve materials with a nitrogen loading as high as 8.6 wt % and well preserved mesopore structure. Using NH3 as nitrogen source dramatically increased the Brunauer-Emmett-Teller (BET) surface area and pore volume of the resultant hybrid material; however, N-doping with melamine as a source resulted in the contrary results. The N-doped carbons were used as supports to immobilize small-sized Pd nanoparticles (PdNPs), which provided a unique platform to investigate the influence of metal nanoparticle size, mesostructural properties, and N-functionalized supports on the selective hydrogenation of phenol to cyclohexanone, an important intermediate in the production of nylon 6 and nylon 66 in the chemical industry. The catalyst with ultrasmall (about 1.2 nm) PdNPs gave the best reaction activity and selectivity under mild conditions. In addition, the present multifunctional catalyst demonstrated excellent catalytic stability and could be used 6 times without loss of product yields. This outstanding catalytic performance could be attributed to the synergetic effects of mesoporous structure, N-functionalized supports, and the stabilized ultrasmall PdNPs. This work might open new avenues for the development of functionalized catalysts with supported ultrasmall metal nanoparticles and hybrid porous support as well as their clean catalyses. © 2013 American Chemical Society.


Guo K.,Chinese Academy of Sciences | Guo K.,University of Chinese Academy of Sciences | Zhong Zheng X.,Chinese Academy of Sciences | Fu H.,University of Iowa
Astrophysical Journal | Year: 2013

A sample of 12,614 star-forming galaxies (SFGs) with stellar mass >109.5 M ⊙ between 0.6 < z < 0.8 from COSMOS is selected to study the intrinsic scatter of the correlation between star formation rate (SFR) and stellar mass. We derive SFR from ultraviolet (UV) and infrared (IR) luminosities. A stacking technique is adopted to measure IR emission for galaxies undetected at 24 μm. We confirm that the slope of the mass-SFR relation is close to unity. We examine the distributions of specific SFRs (SSFRs) in four equally spaced mass bins from 109.5 M ⊙ to 1011.5 M ⊙. Different models are used to constrain the scatter of SSFR for lower mass galaxies that are mostly undetected at 24 μm. The SFR scatter is dominated by the scatter of UV luminosity and gradually that of IR luminosity at increasing stellar mass. We derive SSFR dispersions of 0.18, 0.21, 0.26, and 0.31 dex with a typical measurement uncertainty of ≲ 0.01 dex for the four mass bins. Interestingly, the scatter of the mass-SFR relation seems not constant in the sense that the scatter in SSFR is smaller for SFGs of stellar mass <10 10.5 M ⊙. If confirmed, this suggests that the physical processes governing star formation become systematically less violent for less massive galaxies. The SSFR distribution for SFGs with intermediate mass 1010-1010.5 M ⊙ is characterized by a prominent excess of intense starbursts in comparison with other mass bins. We argue that this feature reflects that both violent (e.g., major/minor mergers) and quiescent processes are important in regulating star formation in this intermediate-mass regime. © 2013. The American Astronomical Society. All rights reserved.


Zha Z.,Luoyang Normal University | Zha Z.,University of Chinese Academy of Sciences | Wang X.,South China Normal University
IEEE Transactions on Information Theory | Year: 2011

In this paper, two new families of functions in odd characteristic are constructed, and they are proved to be almost perfect nonlinear (APN) functions. Some of the open cases which were introduced by Helleseth are answered by these new APN functions. © 2011 IEEE.


Li Q.,CAS Lanzhou Institute of Chemical Physics | Li Q.,University of Chinese Academy of Sciences | Guo Y.,CAS Lanzhou Institute of Chemical Physics | Shao S.,CAS Lanzhou Institute of Chemical Physics
Sensors and Actuators, B: Chemical | Year: 2012

A new BODIPY-based derivative 1 bearing phenolic OH groups was developed as a fluorescent sensor for Cu(II) ions and homocysteine/cysteine. Receptor 1 behaves as an "on-off" fluorescent sensor for the selective and sensitive detection of Cu(II) ions. The mechanism for the fluorescence response of receptor 1 toward Cu(II) ions could be explained by the widely accepted LMCT (ligand to metal charge transfer) process. The 1·Cu(II) could act as an efficient "off-on" fluorescent sensor for homocysteine/cysteine with high sensitivity. © 2012 Published by Elsevier B.V.


Zhu S.-D.,CAS Xishuangbanna Tropical Botanical Garden | Zhu S.-D.,University of Chinese Academy of Sciences | Cao K.-F.,CAS Xishuangbanna Tropical Botanical Garden
Oecologia | Year: 2010

Lianas are an important component of tropical forests and often abundant in open habitats, such as tree-fall gaps, forest edges, and disturbed forests. The abundance of lianas in tropical forests has been increasing as a result of global environmental change and increasing forest fragmentation. In order to understand this phenomenon in terms of leaf functional traits and to evaluate their competitive potential, we conducted a cost-benefit analysis of leaves from 18 liana species and 19 tree species in a tropical seasonal rain forest. The results revealed that lianas were scattered in a group distinct from trees along the first axis of a principal component analysis using 15 leaf ecophysiological traits, being located at the quick-return end of the leaf economics spectrum, with higher specific leaf area and photosynthetic rates (A), higher photosynthetic nitrogen (N) and phosphorus (P) use efficiencies, a lower leaf construction cost per unit leaf area (CC) and cost-benefit ratio (CC/A), and a shorter leaf life span (LLS). Trees showed the opposite trends. The results indicate that lianas can grow faster and capture resources more efficiently than trees in disturbed, open habitats. The positive relationship between LLS and CC/A revealed a trade-off between leaf construction cost and benefit over time. The 37 species analyzed had a mean foliar N/P ratio of 20, indicating that the forest was characterized by a P deficit. With an increasing atmospheric CO2 concentration, the higher nutrient use efficiency could benefit lianas more than trees in terms of productivity, possibly also contributing to the increasing abundance of lianas in nutrient-limited tropical forests. © 2010 Springer-Verlag.


Xu W.,CAS Kunming Institute of Botany | Xu W.,University of Chinese Academy of Sciences | Dai M.,CAS Xishuangbanna Tropical Botanical Garden | Dai M.,University of Chinese Academy of Sciences | And 2 more authors.
Nucleic Acids Research | Year: 2014

Genomic imprinting often results in parent-of-origin specific differential expression of maternally and paternally inherited alleles. In plants, the triploid endosperm is where gene imprinting occurs most often, but aside from studies on Arabidopsis, little is known about gene imprinting in dicotyledons. In this study, we inspected genomic imprinting in castor bean (Ricinus communis) endosperm, which persists throughout seed development. After mapping out the polymorphic SNP loci between accessions ZB306 and ZB107, we generated deep sequencing RNA profiles of F1 hybrid seeds derived from reciprocal crosses. Using polymorphic SNP sites to quantify allele-specific expression levels, we identified 209 genes in reciprocal endosperms with potential parent-of-origin specific expression, including 200 maternally expressed genes and 9 paternally expressed genes. In total, 57 of the imprinted genes were validated via reverse transcriptase-polymerase chain reaction sequencing, and analysis of the genomic DNA methylation distribution between embryo and endosperm tissues showed significant hypomethylation in the endosperm and an enrichment of differentially methylated regions around the identified genes. Curiously, the expression of the imprinted genes was not tightly linked to DNA methylation. These results largely extended gene imprinting information existing in plants, providing potential directions for further research in gene imprinting. © 2014 The Author(s) 2014.


Zhang H.-F.,CAS Lanzhou Institute of Chemical Physics | Zhang H.-F.,University of Chinese Academy of Sciences | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Analyst | Year: 2012

A new solid-phase extraction mode for magnetic retrieval of chitosan combined with high-performance liquid chromatography-diode array detection was proposed for the pre-concentration and determination of flavonoids in green tea beverage samples. In the experiment, chitosan was used as sorbents for the extraction of target analytes; after completion of the extraction process, Fe 3O 4 nanoparticles acted as carrier to retrieve chitosan from the sample solution. Some important parameters influenced extraction efficiency of flavonoids, including the extraction mode, amounts of chitosan, pH of sample solution, extraction time, salt addition, amounts of Fe 3O 4 nanoparticles, desorption solvent and desroption time, were optimized. Under the optimum conditions, the recoveries of analytes done on samples spiked with the target analytes were between 96.4% and 108.6%; relative standard deviations ranged from 0.6% to 8.7%. The correlation coefficients varied from 0.9917 to 0.9988. The limits of detection ranged from 5.4 to 16.8 ng mL -1 at a signal-to-noise ratio of 3. All four different brands of green tea beverage samples were successfully analyzed by the proposed method. © The Royal Society of Chemistry 2012.


Yin Z.-Q.,CAS Wuhan Institute of Physics and Mathematics | Yin Z.-Q.,University of Chinese Academy of Sciences | Li T.,University of Texas at Austin | Feng M.,CAS Wuhan Institute of Physics and Mathematics
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We propose an experimental scheme to cool and measure the three-dimensional (3D) motion of an optically trapped nanosphere in a cavity. Driven by three lasers on TEM00, TEM01, and TEM10 modes, a single cavity can cool a trapped nanosphere to the quantum ground states in all three dimensions under the resolved-sideband condition. Our scheme can also detect an individual collision between a single molecule and a cooled nanosphere efficiently. Such an ability can be used to measure the mass of molecules and the surface temperature of the nanosphere. We also discuss the heating induced by the intensity fluctuation, the pointing instability, and the phase noise of lasers, and justify the feasibility of our scheme under current experimental conditions. © 2011 American Physical Society.


Tai Z.,CAS Lanzhou Institute of Chemical Physics | Tai Z.,University of Chinese Academy of Sciences | Yan X.,CAS Lanzhou Institute of Chemical Physics | Xue Q.,CAS Lanzhou Institute of Chemical Physics
Journal of Power Sources | Year: 2012

In this paper, a graphene/shape-memory polyurethane (PU) composite film, used for a supercapacitor electrode, is fabricated by a simple bonding method. In the composite, formerly prepared graphene paper is closely bonded on the surface of the PU slice, forming a bi-layered composite film. Based on the good flexibility of graphene paper and the outstanding shape holding capacity of PU phase, the resulting composite film can be changed into various shapes. Also, the composite film shows excellent shape recovery ability. The graphene/PU composite film used as the electrode maintains a satisfactory electrochemical capacitance of graphene material and there is no decay in the specific capacitance after long-cycle testing, making it attractive for novel supercapacitors with special shapes and shape-memory ability. © 2012 Elsevier B.V. All rights reserved.


Min S.,CAS Lanzhou Institute of Chemical Physics | Min S.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
Journal of Physical Chemistry C | Year: 2012

Graphitic carbon nitride (g-C 3N 4) is a novel and stable metal-free photocatalyst that can generate H 2 from water under visible light irradiation, but its activity is significantly limited due to the insufficient light absorption in the solar spectrum (weak absorption in the wavelength longer than 460 nm). In this paper, we demonstrate that the photoresponse of the mesoporous g-C 3N 4 (mpg-C 3N 4) can be greatly extended up to nearly 600 nm by sensitization with Eosin Y (EY). This sensitization photocatalyst demonstrates high and rather stable photocatalytic activity for H 2 evolution under visible light irradiation, especially in the longer wavelength regions (450-600 nm). The apparent quantum efficiency (AQE) of 19.4% under 550 nm irradiation has been obtained. These results indicate that efficient electron transfer between excited EY molecules and mpg-C 3N 4 is achieved. The mpg-C 3N 4 with high surface area and nanoporous structure can greatly facilitate EY molecules assembly on the surface, thus promoting the activity via improved light harvesting. © 2012 American Chemical Society.


Tai Z.,CAS Lanzhou Institute of Chemical Physics | Tai Z.,University of Chinese Academy of Sciences | Yan X.,CAS Lanzhou Institute of Chemical Physics | Lang J.,CAS Lanzhou Institute of Chemical Physics | Xue Q.,CAS Lanzhou Institute of Chemical Physics
Journal of Power Sources | Year: 2012

In this work, a flexible and freestanding carbon nanofiber/graphene nanosheet (CNF/GNS) composite paper is prepared via electrospinning followed by high-temperature annealing using a polyacrylonitrile/GNS/dimethylformamide mixture as electrospun precursor. The structure characterizations show that GNS homogeneously distributes in the CNF, forming a thin, light-weight and flexible composite paper. Due to the reinforcing effects coming from CNF and GNS, the Brunauer Emmett Teller (BET) specific surface area, conductivity and capacitance performance of pure CNF are significantly improved after adding GNS. The GNS/CNF composite paper exhibits the largest specific capacitance of 197 F g -1, about 24% higher than that of pure CNF paper. Therefore, based on the above investigations, such GNS/CNF composite paper can be a potential candidate for high-performance flexible capacitors. © 2011 Elsevier B.V. All rights reserved.


Wang B.,CAS Xishuangbanna Tropical Botanical Garden | Wang B.,University of Chinese Academy of Sciences | Chen J.,CAS Xishuangbanna Tropical Botanical Garden
PLoS ONE | Year: 2011

The mutualistic interaction between scatter-hoarding rodents and their seed plants is highly complex yet poorly understood. Plants may benefit from the seed dispersal behavior of rodents, as long as seed consumption is minimized. In parallel, rodents may maximize foraging efficiency and cache high-quality resources for future consumption. Defensive compounds, such as tannins, are thought to be a major mechanism for plant control over rodent behavior. However, previous studies, using naturally occurring seeds, have not provided conclusive evidence supporting this hypothesis. Here, we test the importance of tannin concentrations on the scatter-hoarding behavior of rodents by using an artificial seed system. We combined feeding trials and field observations to examine the overall impact of seed tannin concentrations on rodent behavior and health. We found that rodents favored seeds with an intermediate amount of tannin (~5%) in the field. Meanwhile, in rodents that were fed a diet with different tannin content, only diets with high tannin content (25%, 15%, and 10%) caused a significant negative influence on rodent survival and health. Significant differences were not found among treatments with tannin levels of 0-5%. In contrast to many existing studies, our results clearly demonstrate that scatter-hoarding rodents prefer slightly 'astringent' food. In the co-evolutionary arms race between plants and animals, our results suggest that while tannins may play a significant role in reducing general predation levels by the faunal community, they have no precise control over the behavior of their mutualistic partner. Instead, the two partners appear to have reached an evolutionary point where both parties receive adequate benefits, with the year-to-year outcome being dependent on a wide range of factors beyond the control of either partner. © 2011 Wang, Chen.


Yan J.,CAS Lanzhou Institute of Chemical Physics | Yan J.,University of Chinese Academy of Sciences | Zhou F.,CAS Lanzhou Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2011

This review starts with a brief introduction to TiO2 nanotubes (NTs), and then discusses in more detail how to optimize the structure of TiO2 NTs for the fabrication of highly efficient solar cells, including the controllable fabrication of perfectly aligned TiO2 NTs, optimizing the tube parameters, strategies of sensitization, improvement of the interface adhesion in polymer/TiO2 solar cells and how to make devices flexible. Some key challenges and perspectives for future research are also tentatively discussed. © 2011 The Royal Society of Chemistry.


Min S.,CAS Lanzhou Institute of Chemical Physics | Min S.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
Journal of Physical Chemistry C | Year: 2012

The development of an advanced cocatalyst is critical for improving the efficiency of the photocatalytic hydrogen evolution reaction. Noble metals such as platinum (Pt) have been identified to be the most active cocatalyst for this reaction; however, due to their low-abundance, high cost, their usage in the scale-up setup is impeditive. Here, we report a high active cocatalyst, limited-layered MoS2 confined on RGO sheets as an alternative of Pt, for hydrogen evolution in dye-sensitized photocatalytic systems. Growing a MoS2 cocatalyst on RGO sheets provides more available catalytically edge sites and thus exhibits much higher activity than large aggregated pristine MoS2 particles under visible light irradiation (420 nm). The apparent quantum efficiency (AQE) of 24% at 460 nm over an Eosin Y-sensitized MoS2/RGO photocatalyst has been achieved. In addition, the electrical coupling and synergistic effect between MoS2 and RGO sheets greatly facilitate the efficient electron transfer from photoexcited dye to the active edge sites of MoS2; as a result, the prolonged lifetime of photogenerated electrons and the improved charge separation efficiency have been accomplished, and the photocatalytic hydrogen evolution activity has been enhanced significantly. This work demonstrates that the structural integration of MoS2 with RGO will be a new promising strategy to develop a high efficient and low-cost non-noble metal cocatalyst for solar hydrogen generation. © 2012 American Chemical Society.


Song Y.,State Key Laboratory of Rare Earth Resource Utilization | Song Y.,University of Chinese Academy of Sciences | Wei W.,State Key Laboratory of Rare Earth Resource Utilization | Qu X.,State Key Laboratory of Rare Earth Resource Utilization
Advanced Materials | Year: 2011

In recent years, colorimetric biosensing has attracted much attention because of its low cost, simplicity, and practicality. Since color changes can be read out by the naked eye, colorimetric biosensing does not require expensive or sophisticated instrumentation and may be applied to field analysis and point-of-care diagnosis. For transformation of the detection events into color changes, a number of smart materials have been developed, including gold nanoparticles, magnetic nanoparticles, cerium oxide nanoparticles, carbon nanotubes, graphene oxide, and conjugated polymers. Here, we focus on recent developments in colorimetric biosensing using these smart materials. Along with introducing the mechanisms of color changes based on different smart materials, we concentrate on the design of biosensing assays and their potential applications in biomedical diagnosis and environmental monitoring. For transformation of the detection events into color changes, a number of smart materials have been developed, including gold nanoparticles, magnetic nanoparticles, cerium oxide nanoparticles, carbon nanotubes, graphene oxide, and conjugated polymers. Recent developments in colorimetric biosensing using these smart materials and their applications in biomedical diagnosis and environmental monitoring are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wang Y.,CAS Lanzhou Institute of Chemical Physics | Wang Y.,University of Chinese Academy of Sciences | Liu J.,CAS Lanzhou Institute of Chemical Physics | Xia C.,CAS Lanzhou Institute of Chemical Physics
Advanced Synthesis and Catalysis | Year: 2011

Cross-linked polymeric ionic liquid material-supported copper (Cu-CPSIL), imidazolium-loaded Merrifield resin-supported copper (Cu-PSIL) and silica dispersed CuO (CuO/SiO2), were prepared and proved to be efficient catalysts for the one-pot synthesis of 1,4-disubsituted-1,2,3-triazoles by the reaction of alkyl halides with sodium azide and terminal alkynes in water at room temperature. Moreover, these supported copper catalysts were recovered quantitatively from the reaction mixture by simple filtration and reused for five consecutive recycles without significant loss of catalytic activity. Among the three immobilized copper catalysts, Cu-CPSIL exhibited excellent catalytic activity for the reaction of aliphatic bromides, sodium azide and terminal alkynes. The differences in the catalytic performances of the catalysts could be ascribed to the copper dispersion and the interaction between copper and the supports. In addition, water was used as the reaction media and the proton provider, the latter was found to be very important for the reaction. The XPS results suggested that the supported Cu(II) catalysts were reduced to catalytic Cu(I) species via alkynes homocoupling reaction. By means of IR and ESI-MS studies, a possible mechanism of cycloaddition based on the reduction of Cu(II) to Cu(I) species was proposed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Hu X.,CAS Lanzhou Institute of Chemical Physics | Hu X.,University of Chinese Academy of Sciences | Lu G.,CAS Lanzhou Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2010

Biomass is carbon-neutral and utilization of biomass as hydrogen resource shows no impact on atmospheric CO2 level. Nevertheless, a significant amount of CO2 is always produced in biomass gasification processes. If the CO2 produced can further react with biomass, then the biomass gasification coupled with CO2 reforming of biomass will result in a net decrease of CO2 level in atmosphere and produce the chemical raw material, syngas. To achieve this concept, a "Y" type reactor is developed and applied in bio-oil steam reforming, partial oxidation, or oxidative steam reforming coupled with CO2 reforming of bio-oil to eliminate the emission of CO2. The experimental results show that the reaction systems can efficiently suppress the emission of CO2 from various reforming processes. The different coupled reaction systems generate the syngas with different molar ratio of CO/H2. In addition, coke deposition is encountered in the different reforming processes. Both catalysts and experimental parameters significantly affect the coke deposition. Ni/La 2O3 catalyst shows much higher resistivity toward coke deposition than Ni/Al2O3 catalyst, while employing high reaction temperature is vital for elimination of coke deposition. Although the different coupled reaction systems show different characteristic in terms of product distribution and coke deposition, which all can serve as methods for storage of the carbon from fossil fuels or air. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.


Liu W.-W.,CAS Lanzhou Institute of Chemical Physics | Liu W.-W.,University of Chinese Academy of Sciences | Feng Y.-Q.,CAS Lanzhou Institute of Chemical Physics | Yan X.-B.,CAS Lanzhou Institute of Chemical Physics | And 2 more authors.
Advanced Functional Materials | Year: 2013

Graphene quantum dots (GQDs) have attracted tremendous research interest due to the unique properties associated with both graphene and quantum dots. Here, a new application of GQDs as ideal electrode materials for supercapacitors is reported. To this end, a GQDs//GQDs symmetric micro-supercapacitor is prepared using a simple electro-deposition approach, and its electrochemical properties in aqueous electrolyte and ionic liquid electrolyte are systematically investigated. The results show that the as-made GQDs micro-supercapacitor has superior rate capability up to 1000 V s-1, excellent power response with very short relaxation time constant (τ0 = 103.6 μs in aqueous electrolyte and τ0 = 53.8 μs in ionic liquid electrolyte), and excellent cycle stability. Additionally, another GQDs//MnO2 asymmetric supercapacitor is also built using MnO2 nanoneedles as the positive electrode and GQDs as the negative electrode in aqueous electrolyte. Its specific capacitance and energy density are both two times higher than those of GQDs//GQDs symmetric micro-supercapacitor in the same electrolyte. The results presented here may pave the way for a new promising application of GQDs in micropower suppliers and microenergy storage devices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wu L.,CAS Lanzhou Institute of Chemical Physics | Wu L.,University of Chinese Academy of Sciences | Zhang J.,CAS Lanzhou Institute of Chemical Physics | Li B.,CAS Lanzhou Institute of Chemical Physics | Wang A.,CAS Lanzhou Institute of Chemical Physics
Polymer Chemistry | Year: 2014

A facile approach for preparing magnetically driven durable superhydrophobic polyester materials is developed by simply dip-coating in a nanocomposite solution. The nanocomposite is prepared by the polymerization of tetraethoxysilane and n-hexadecyltriethoxysilane in the presence of the Fe 3O4 nanoparticles. The coated magnetic samples exhibit excellent superhydrophobicity, superoleophilicity, and mechanical and chemical stability, owing to the tight binding of the nanocomposite on the polyester materials and the inherent stability of the polymerized organosilanes. The superhydrophobic materials can quickly absorb petrol, diesel and crude oil, and show very high selectivity in oil/water separation. In addition, the superhydrophobic materials could maintain their superhydrophobicity, oil absorption capacity and oil/water selectivity after a large amount of mechanical damage, 90 days of immersion in oil and ten cycles of absorption-desorption. Moreover, the coated sample can be magnetically driven to the polluted water zone using a magnet. Also, the facile approach can be easily scaled up for producing samples on a large scale, which makes it very promising for practical oil absorption. © 2014 The Royal Society of Chemistry.


Li B.,CAS Lanzhou Institute of Chemical Physics | Li B.,University of Chinese Academy of Sciences | Yu B.,CAS Lanzhou Institute of Chemical Physics | Ye Q.,CAS Lanzhou Institute of Chemical Physics | Zhou F.,CAS Lanzhou Institute of Chemical Physics
Accounts of Chemical Research | Year: 2015

ConspectusPolymer brushes are becoming increasing popular in the chemical literature, because scientists can control their chemical configuration, density, architecture, and thickness down to nanoscale precision with even simple laboratory setups. A polymer brush is made up of a layer of polymers attached to a substrate surface at one end with the other end dangling into a solvent. In a suitable solvent, the polymer chains stretch away from the surface due to both steric and osmotic repulsion between the chain segments. In an inadequate solvent, however, the polymer chains collapse due to enough interior free space after desolvation. This unique class of materials exhibit interesting physicochemical properties at interfaces and have numerous applications from sensing to surface/interface property control.Chemists have made recent advances in surface modification and specific application of polymer brushes, due to both profound mechanistic understanding and synthetic strategies. The commonly used synthetic strategies for generating polymer brushes are surface-initiated polymerizations (SIPs), which resemble planting rice. That is, the assembly of initiator on the surface is similar to transplanting rice seedlings, and the subsequent polymerizations are akin to rice growth. Among different SIP methods, researchers mostly use surface-initiated atom transfer radical polymerization (SI-ATRP) because it provides many advantages in the preparation of well-defined polymer brushes, including easy initiator synthesis, fair control over polymer growth, a "living" end for copolymer grafting, and polymerization in aqueous solution. However, chemists gradually realized that there still room for improvement in this method, since the conventional SI-ATRP method suffers several drawbacks. These include having limited availability on various materials surfaces, rigorous synthetic protocols, heavy consumption and waste of unreacted monomers, and limited ability to control a polymerization process. Moreover, applications of polymer brushes as model surfaces must benefit from the synergistic strategies and profound insights into the fundamental understanding of the polymerization. This is not only to optimize the SI-ATRP process but also to expand the range of monomers, simplify reaction setups, reduce the cost, and ultimately gain control of the synthesis of well-defined polymeric surfaces for material science and engineering.In this Account, we provide an overview of our and others' recent advances in the fabrication of polymer brushes by using SI-ATRP, to promote the widespread application of SI-ATRP and practical applications of the polymer brushes. We aim to provide fundamental mechanistic and synthetic features of SI-ATRP, while emphasizing the various externally applied stimuli mediated catalytic and initiation systems, including electrochemistry, chemical reducing agents, and photochemistry. In addition, we discuss how chemists can advantageously exploit these methods to synthesize functional polymeric surfaces in environmentally friendly media and facilitate in situ regulation of a dynamic polymerization process.We also discuss structural polymer brushes, such as block copolymers and patterned and gradient structures. Finally, we provide examples that highlight some practical applications of polymer brushes using SI-ATRP, especially the emerging polymerization methods. Overall, recently developed SI-ATRP systems overcome many limitations that permit less rigorous synthetic protocols and facilitate scientific community-wide access to surface modifications. By using these methodologies, chemists are tapping the potential of polymer brushes in surface/interface research areas. © 2014 American Chemical Society.


Wei Q.,CAS Lanzhou Institute of Chemical Physics | Wei Q.,University of Chinese Academy of Sciences | Wang X.,CAS Lanzhou Institute of Chemical Physics | Zhou F.,CAS Lanzhou Institute of Chemical Physics
Polymer Chemistry | Year: 2012

A versatile macro-initiator with dual functional anchoring groups for surface-initiated atom transfer radical polymerization (SI-ATRP) on various substrates is reported. Conventional free radical copolymerization was performed with N-(3,4-dihydroxyphenyl) ethyl methacrylamide (a dopamine anchor-containing monomer), 4-(1-pyrenyl) butyl methacrylate (a pyrene anchor-containing monomer), and 2-(2-bromoisobutyryloxy) ethyl methacrylate (an ATRP-initiating monomer) to produce a random copolymer. Dopamine anchors on the copolymer could assemble on the macroscopic planar substrates (e.g., Si, Ti, Au, Cu, stainless steel, Al 2O 3, PI, PTFE, PDMS, textile, and wood) and pyrene anchors on the carbon-based nanoscaled materials (e.g., two-dimensional graphene oxide and one-dimensional carbon nanotubes). The successful preparation of polymer brushes through SI-ATRP in a water and methanol system from various substrates was characterized via ATR-IR, AFM, XPS, TGA, and TEM, which confirmed the versatility of the macro-initiator. More importantly, a synergistic anchoring effect between catechol and pyrene groups was discovered, leading to high quantities of grafted polymers from the graphene oxide substrates. Microcontact printing of the macro-initiator was also demonstrated in the formation of patterned surfaces on the Ti substrate. © 2012 The Royal Society of Chemistry.


Cui L.,CAS Lanzhou Institute of Chemical Physics | Cui L.,University of Chinese Academy of Sciences | Lu Z.,CAS Lanzhou Institute of Chemical Physics | Wang L.,CAS Lanzhou Institute of Chemical Physics
Carbon | Year: 2014

The lubrication of diamond-like carbon (DLC) films has commonly been ascribed to two hypotheses, i.e., 'friction-induced graphitization' mechanism and passivation mechanism. To clarify the primary low-friction mechanism of DLC, we investigate the effects of sliding velocity and vacuum pressure on the friction behavior of DLC film. Counterintuitively, examination of wear tracks by Raman spectroscopy reveals that a higher friction coefficient is accompanying with a higher degree of graphitization. We therefore claim that it is the higher friction force that results in the higher degree of graphitization, which subverts the concept of a higher degree of graphitization leading to a lower friction coefficient. Besides, the friction coefficient is found to depend on the ratio of ambient pressure to rotating speed, indicating that the passivation mechanism is at play. Besides, the additional slide-hold-slide test in room air also gives evidence that cannot be understood in terms of the 'friction-induced graphitization' mechanism. © 2013 Elsevier Ltd. All rights reserved.


Wang T.-Y.,Luoyang Normal University | Wang T.-Y.,University of Chinese Academy of Sciences | Wei Z.-L.,Luoyang Normal University
Quantum Information Processing | Year: 2012

We propose a new one-time proxy signature scheme with decoherence-free states. We analyze its security and show that it is not possible to forge a valid proxy signature even if an opponent has infinite resources. Furthermore, the differences between this scheme and others are discussed. © 2011 Springer Science+Business Media, LLC.


Zhang H.-F.,CAS Lanzhou Institute of Chemical Physics | Zhang H.-F.,University of Chinese Academy of Sciences | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Talanta | Year: 2010

In this article, a novel method termed as temperature-assisted ionic liquid dispersive liquid-liquid microextraction (TA IL-DLLME) combining high performance liquid chromatography with diode array detection (HPLC-DAD) was developed for the determination of anthraquinones in Radix et Rhizoma Rhei samples. The ionic liquid (1-hexyl-3-methylimidazolium hexafluorophosphate) was used to replace volatile organic solvent as an extraction solvent for the extraction of anthraquinones (aloe-emodin, rhein, emodin, chrysophanol and physcion) from Radix et Rhizoma Rhei. Several important parameters influencing the extraction efficiency of TA IL-DLLME such as the type and volume of extraction solvent and disperser solvent, sample pH, extraction time, extraction temperature, centrifugation time as well as salting-out effects were optimized. Under the optimal conditions, the spiked recovery for each analyte was in the range of 95.2-108.5%. The precisions of the proposed method were varied from 1.1% to 4.4% (RSD). All the analytes exhibited good linearity with correlation coefficients (r2) ranging from 0.9986 to 0.9996. The limits of detection for all target analytes were ranged from 0.50 to 2.02 μg L -1 (S/N = 3). The experimental results indicated that the proposed method was successfully applied to the analysis of anthraquinones in Radix et Rhizoma Rhei. © 2010 Elsevier B.V.


Sun D.,CAS Lanzhou Institute of Chemical Physics | Sun D.,University of Chinese Academy of Sciences | Yang J.,CAS Lanzhou Institute of Chemical Physics | Yan X.,CAS Lanzhou Institute of Chemical Physics
Chemical Communications | Year: 2015

Novel hierarchically porous and nitrogen, sulfur-codoped graphene-like microspheres (3D NS-GSs) are synthesized using Ni microspheres as the template and using poly(vinylpyrrolidone) and (NH4)2S2O8 as the carbon and nitrogen precursor, respectively. As an anode material in lithium ion batteries, the 3D NS-GS electrode displays a superior capacity with excellent cycling stability. This journal is © The Royal Society of Chemistry 2015.


Yin J.,CAS Lanzhou Institute of Chemical Physics | Yin J.,University of Chinese Academy of Sciences | Jia J.,CAS Lanzhou Institute of Chemical Physics
CrystEngComm | Year: 2014

This paper presents an investigation on the synthesis and characterization of Cu3BiS3 nanosheet films on a TiO2/FTO substrate by a solvothermal route and the photoelectrochemical characteristics of the Cu3BiS3/TiO2 composite films are demonstrated as well. The results show that Cu3BiS3 nanosheets with an average thickness of 30 nm were successfully synthesized on the surface of TiO2 nanorod arrays. The photoelectric properties of the Cu3BiS3/TiO2 composite film indicate that the fill factor of the film photoelectrode is 60.8%, and the energy conversion efficiency is 1.281%, which is higher than that of a bare TiO2 nanorod array photoelectrode. This journal is © 2014 The Royal Society of Chemistry.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: SSH-2007-4.3-01 | Award Amount: 1.86M | Year: 2009

In 2007, China overtook Germany as the worlds largest exporter. Its trade surplus with the EU is rising at $20 million an hour. China makes up one-third of the annual increase in world oil demand, and emits the most greenhouse gases. Engaging a rapidly rising China is a great challenge for the EU. To do this more effectively, the EU needs a comprehensive understanding of China, especially of how the EU and its China initiatives and strategies are perceived in China itself. Through surveys, interviews, and focus groups, this study looks into how the EU is perceived by the Chinese general public, government officials, intellectuals, business and civil society. It will produce a comprehensive picture of how Chinese people see the EU: how China views its opportunities and challenges in dealing with the EU, how different government agencies view the EU, how government views differ from those of business and civil society, and how opinion in Beijing differs from that in the provinces. The recommendations from this study will lead to much more effective policies for the EU to deal with China, helping to reduce market restrictions, resolve the conflict over Chinas exchange rate policy, lift barriers to EU investment in China, increase EU `green technology exports etc. A mere 5% increase in EU exports to China will make a difference of 3.2 billion per year to the EU economy. Our policy recommendations will facilitate greater cooperation on issues such as the Iran nuclear crisis, significantly improving the EUs security. Our findings will contribute to a better projection of the EUs image, enhancing the EUs soft power in China. The project brings together a uniquely strong team from the University of Nottinghams China Policy Institute, Leiden University, Jacobs University Bremen and Chatham House, as well as two strong Chinese partners. New knowledge from this research will help advance a number of social science disciplines.


Wang D.,CAS Lanzhou Institute of Chemical Physics | Wang D.,University of Chinese Academy of Sciences | Wang Q.,CAS Lanzhou Institute of Chemical Physics | Wang T.,CAS Lanzhou Institute of Chemical Physics
Inorganic Chemistry | Year: 2011

In this work, one-dimensional and layered parallel folding of cobalt oxalate nanostructures have been selectively prepared by a one-step, template-free, water-controlled precipitation approach by simply altering the solvents used at ambient temperature and pressure. Encouragingly, the feeding order of solutions played an extraordinary role in the synthesis of nanorods and nanowires. After calcination in air, the as-prepared cobalt oxalate nanostructures were converted to mesoporous Co3O4 nanostructures while their original frame structures were well maintained. The phase composition, morphology, and structure of the as-obtained products were studied in detail. Electrochemical properties of the Co3O4 electrodes were carried out using cyclic voltammetry (CV) and galvanostatic charge-discharge measurements by a three-electrode system. The electrochemical experiments revealed that the layered parallel folding structure of mesoporous Co3O4 exhibited higher capacitance compared to that of the nanorods and nanowires. A maximum specific capacitance of 202.5 F g -1 has been obtained in 2 M KOH aqueous electrolyte at a current density of 1 A g-1 with a voltage window from 0 to 0.40 V. Furthermore, the specific capacitance decay after 1000 continuous charge-discharge cycles was negligible, revealing the excellent stability of the electrode. These characteristics indicate that the mesoporous Co 3O4 nanostructures are promising electrode materials for supercapacitors. © 2011 American Chemical Society.