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An Q.,Beijing Jiaotong University | Zhang F.,Beijing Jiaotong University | Li L.,Beijing Jiaotong University | Zhuo Z.,Beijing Jiaotong University | And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2014

We present a route to successfully tackle the two main limitations, low open circuit voltage (Voc) and limited short circuit-density (J sc), of polymer solar cells (PSCs) based on poly(3-hexylthiophene) (P3HT) as an electron-donor. The indene-C60 bisadduct (ICBA) was selected as an electron acceptor to improve the open circuit voltage (Voc). The narrow band gap polymer poly[(4,8-bis-(2-ethylhexyloxy)-benzo[1,2-b:4,5- b′]dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene) -2,6-diyl] (PBDTTT-C), as a complementary electron-donor material, was doped into the host system of P3HT:ICBA to form ternary cascade energy structured PSCs with increased Jsc. The power conversion efficiency (PCE) of P3HT:ICBA-based cells was improved from 3.32% to 4.38% by doping with 3 wt% PBDTTT-C with 1 min 150 °C annealing treatment. The 4.38% PCE of ternary PSCs is still larger than the 3.79% PCE of PSCs based on P3HT:ICBA with 10 minutes 150 °C annealing treatment. This journal is © the Partner Organisations 2014.


Zhang M.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | Zhang Y.,Nankai University | Zhang Y.,CAS Dalian Institute of Chemical Physics
Nanotechnology | Year: 2011

In this study, a novel route for the preparation of magnetite (Fe 3O4) nanoparticles (NPs) with immobilized metal affinity ligand iminodiacetic acid (IDA) charged with Cu2+ was developed. First, magnetite nanoparticles were synthesized by a hydrothermal method. Charged with Cu2+, the magnetic nanoparticles (MNPs) were applied to separate a model protein mixture of bovine hemoglobin (BHb) and bovine serum albumin (BSA). They could be separated completely and showed low non-specific adsorption. The morphology, structure and composition of the magnetite MNPs were characterized by transmission electron microscopy, power x-ray diffraction, x-ray photoelectron spectrometry and Fourier transform infrared spectroscopy. The resulting magnetite MNPs charged with Cu2+ show not only a strong magnetic response to externally applied magnetic field, but are also highly specific to protein BHb. It is interesting that MNPs modified with metal ligands showed a property of magnetic colloid photonic crystals. Furthermore, they could efficiently remove the abundant protein bovine hemoglobin from bovine blood. They have potential application in removing abundant protein in proteomic analysis. © 2011 IOP Publishing Ltd.


Xu Y.,Nankai University | Jia X.-H.,CAS Institute of Automation | Yin X.-B.,Nankai University | He X.-W.,Nankai University | And 2 more authors.
Analytical Chemistry | Year: 2014

Magnetic resonance imaging (MRI) is used extensively for clinical diagnoses. It is critical to design and develop highly efficient MR contrast agents with simple preparation procedure, low toxicity, and high biocompatibility. Here, we report a carbon quantum dots (CQDs)-stabilized gadolinium hybrid nanoprobe (Gd-CQDs) prepared via a one-pot hydrothermal treatment of the mixture of citrate acid, ethanediamine, and GdCl3 at 200°C for 4 h. In vitro and in vivo tests confirmed their low toxicity and high biocompatibility. Gd-CQDs were observed to have a higher MR response than gadopentetic acid dimeglumine (Gd-DTPA) because of their high Gd content and hydrophilicity. Moreover, the fluorescence of CQDs was remained in Gd-CQDs. The in vivo MR and fluorescence dual-modality imaging of Gd-CQDs was confirmed with zebrafish embryo and mice as models. The modification of Gd-CQDs with arginine-glycine-aspartic acid (RGD) tripeptide provided a high affinity to U87 cancer cells for targeted imaging. Whereas the MR response showed a depth penetration and spatial visualization, fluorescence revealed the fine distribution of Gd-CQDs in tissues because of its high resolution and sensitivity. We found that Gd-CQDs distributed in the tissues in a heterogeneous mode: they entered into the tissue cells but were observed less in the extracellular matrix. The MR and fluorescence dual-modality imaging of Gd-CQDs makes them a potential contrast agent for clinic applications because of their simple preparation procedure, ease of functionalization, high contrast efficiency, low toxicity, and high biocompatibility. (Figure Presented). © 2014 American Chemical Society.


Sun L.,Tufts University | Wang X.,Tufts University | Wang X.,CAS Dalian Institute of Chemical Physics | Kaplan D.L.,Tufts University
Biomaterials | Year: 2011

Inflammation plays a major role in the destruction of cartilage in osteoarthritis (OA), with the interaction of multiple mediators, immune cells, fibroblasts and chondrocytes. Current 2D studies in vitro with cell lines, as well as animal models, are limited in terms of providing insight into pathogenic mechanisms related to the human system. Hence, an in vitro human 3D cartilage tissue system was established to study the impact of inflammatory mediators on chondrocytes and matrices as an initial approach to emulating early stages of OA. An in vitro 3D human cartilage tissue system was established by culturing primary chondrocytes in silk protein porous scaffolds up to 21 days in static culture, with and without cytokine (IL-1β and TNF-α) exposure or with the use of macrophage conditioned medium (MCM). To assess chondrocyte responses, transcript levels, histology and immunohistochemistry were used to assess changes in cell viability and in cartilage matrix composition, including collagen type II and aggrecan. Chondrocyte hypertrophy and apoptosis were assessed via collagen type X and caspase-3. RT-PCR revealed that the cytokines and the MCM regulated matrix-related gene expression of chondrocytes, but with different outcomes. For anabolic-encoding genes, MCM suppressed collagen type II and upregulated aggrecan. In contrast, the cytokines suppressed aggrecan formation and had no effect on collagen type II. For catabolic-encoded genes, both cytokines and MCM upregulated MMP1, MMP3, MMP13 and ADAMTS4, with cytokines preferentially upregulating MMP13 and MCM upregulating ADMTS4. MCM down-regulated ADAMTS5. In addition, MCM stimulation led to hypertrophy and apoptosis of chondrocytes, outcomes not found with the cytokine treatment group. A decrease in aggrecan content with cytokines and MCM stimulation was found, while MCM resulted in greater reduction than the cytokine treatment. The results demonstrated that OA-like features, such as changes in matrix synthesis gene expression, increase of collagense gene expression and loss of aggrecan, were initiated within this 3D chrondrocyte human tissue system upon stimulation of the cultures with cytokines and MCM. MCM was a better inducer of immune-related features of OA, because besides the features found with cytokine stimulation, the MCM treatment also initiated collagen X expression and deposition and apoptosis of chondrocytes, important features of human OA. The results obtained with this new in vitro tissue model provide an initial step towards the development of an early stage OA system to allow for more systematic study and insight into the origins and outcomes with this disease. © 2011 Elsevier Ltd.


Feng L.,Liaoning University of Technology | Feng L.,CAS Dalian Institute of Chemical Physics | Liu H.,Liaoning University of Technology
Physics of Plasmas | Year: 2015

A promising method to generate the attosecond extreme ultraviolet (XUV) sources has been theoretically investigated emerging from the two-dimensional Ar+ cluster driven by the spatially inhomogeneous field. The results show that with the introduction of the Ar+ cluster model, not only the harmonic cutoffs are enhanced, but also the harmonic yields are reinforced. Furthermore, by properly moderating the inhomogeneity as well as the laser parameters of the inhomogeneous field, the harmonic cutoff can be further extended. As a result, three almost linearly polarized XUV pulses with durations of 40as, 42as, and 45as can be obtained. © 2015 AIP Publishing LLC.


Xie C.,Nanjing University | Ma J.,University of New Mexico | Ma J.,University of Sichuan | Zhu X.,Johns Hopkins University | And 5 more authors.
Journal of Physical Chemistry Letters | Year: 2014

Full-dimensional state-to-state quantum dynamics of the photodissociation of NH3(Ã1A2'') is investigated on newly developed coupled diabatic potential energy surfaces. For the first time, the rovibrational distributions of the nonadiabatically produced NH 2(X̃2B1) product have been determined quantum mechanically. In agreement with experimental observations, NH 2(X̃2B1) produced from the 00 and 21 states of NH3(Ã1A2'') was found to be dominated by its ground vibrational state with an N = K a propensity, shedding light on the quantum-state-resolved nonadiabatic dynamics facilitated by conical intersections and setting the stage for the elucidation of vibrationally mediated photodissociation. © 2014 American Chemical Society.


Takei T.,Tokyo Metroplitan University | Akita T.,Japan National Institute of Advanced Industrial Science and Technology | Nakamura I.,Japan National Institute of Advanced Industrial Science and Technology | Fujitani T.,Japan National Institute of Advanced Industrial Science and Technology | And 5 more authors.
Advances in Catalysis | Year: 2012

Gold can be deposited as nanoparticles (NPs) with diameters of 2-5. nm and clusters with diameters less than 2. nm on a variety of materials such as oxides, carbides, and sulfides of transition metals, carbons, and organic polymers. Such supported gold NPs and clusters exhibit surprisingly high catalytic activities for many reactions, with both gas- and liquid-phase reactants, in particular, at temperatures below 573. K. Until now, more than 10 techniques have been developed for depositing gold as NPs and clusters. The atomic scale structures of supported NPs and clusters have been extensively and intensively investigated with a high-resolution transmission electron microscopy.The mechanisms of catalysis by supported gold NPs have recently been elucidated by using real powder catalysts and model single-crystal catalysts for the low-temperature oxidation of CO. Another simple reaction that has recently been investigated is dihydrogen dissociation, for which gold NP catalysts are still poorly active. Both of these reactions have been demonstrated to take place at perimeter interfaces around the gold NPs. This result means that there is a great chance for gold to exhibit high catalytic activity for hydrogenation reactions by an appropriate choice of metal oxide supports and by minimizing the diameters of gold particles. The catalytic nature of gold clusters has also been investigated theoretically in relation to the effect of cluster size and the influence of organic ligands and polymers.The catalytic performance of gold NPs and clusters has been explored extensively for reactions of both gases and liquids. Supported gold catalysts are useful for air cleaning at room temperature, and they are valuable for green production of bulk and fine chemicals. Supported gold clusters are expected to open new doors for simple chemistry for the selective manufacture of needed products. Size and structure specificity are expected to present opportunities for selective conversions. It is recommended that researchers explore the magic numbers and structures of gold and suitable support materials for selected target reactions. © 2012 Elsevier Inc..


Wang Y.,Northwest University, China | Li Y.,Dalian University of Technology | Ma Z.,Northwest University, China | Yang W.,Northwest University, China | Ai C.,CAS Dalian Institute of Chemical Physics
PLoS Computational Biology | Year: 2010

MicroRNAs (miRNAs) are endogenously produced ~21-nt riboregulators that associate with Argonaute (Ago) proteins to direct mRNA cleavage or repress the translation of complementary RNAs. Capturing the molecular mechanisms of miRNA interacting with its target will not only reinforce the understanding of underlying RNA interference but also fuel the design of more effective small-interfering RNA strands. To address this, in the present work the RNA-bound (Ago-miRNA, Ago-miRNAtarget) and RNA-free Ago forms were analyzed by performing both molecular dynamics simulations and thermodynamic analysis. Based on the principal component analysis results of the simulation trajectories as well as the correlation analysis in fluctuations of residues, we discover that: 1) three important (PAZ, Mid and PIWI) domains exist in Argonaute which define the global dynamics of the protein; 2) the interdomain correlated movements are so crucial for the interaction of Ago-RNAs that they not only facilitate the relaxation of the interactions between residues surrounding the RNA binding channel but also induce certain conformational changes; and 3) it is just these conformational changes that expand the cavity of the active site and open putative pathways for both the substrate uptake and product release. In addition, by thermodynamic analysis we also discover that for both the guide RNA 5′-end recognition and the facilitated site-specific cleavage of the target, the presence of two metal ions (of Mg2+) plays a predominant role, and this conclusion is consistent with the observed enzyme catalytic cleavage activity in the ternary complex (Ago-miRNA-mRNA). Our results find that it is the set of arginine amino acids concentrated in the nucleotide-binding channel in Ago, instead of the conventionally-deemed seed base-paring, that makes greater contributions in stabilizing the binding of the nucleic acids to Ago. © 2010 Wang et al.


Zhang W.,Nankai University | He X.-W.,Nankai University | Yang Y.-Q.,Nankai University | Li W.-Y.,Nankai University | And 2 more authors.
Journal of Materials Chemistry B | Year: 2013

In this work, aminophenylboronic acid functionalized mesoporous silica coated CdTe quantum dots (APBA-coated QDs) were synthesized and applied to the selective capture and fluorescent quantification of glycoproteins. The as-prepared APBA-coated QDs, relying on the interaction between APBA and cis-diol containing structures, demonstrated excellent selectivity for the glycoproteins. Their high surface area and APBA-enriched silica matrixes give rise to faster binding kinetics and higher binding capacity for the glycoproteins, which further make them attractive for biomedical/chemical sensing applications. Based on the fluorescent properties of the particles, the as-prepared APBA-coated QDs were successfully applied to the fluorescence quantification of glycoproteins. The present study provides a facile strategy to fabricate functionalized fluorescent materials and is of great significance for isolation and detection of glycoproteins in proteomics. © 2013 The Royal Society of Chemistry.


Hou J.,Virginia Polytechnic Institute and State University | Yang M.,Virginia Polytechnic Institute and State University | Ellis M.W.,Virginia Polytechnic Institute and State University | Moore R.B.,Virginia Polytechnic Institute and State University | Yi B.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2012

Lithium-air/oxygen battery is a rising star in the field of electrochemical energy storage as a promising alternative to lithium ion batteries. Nevertheless, this alluring system is still at its infant stage, and the breakthrough of lithium-air batteries into the energy market is currently constrained by a combination of scientific and technical challenges. Targeting at the air electrode in nonaqueous lithium-air batteries, this review attempts to summarize the knowledge about the fundamentals related to lithium oxides precipitation, which has been one of the vital and attractive aspects of the research communities of science and technology. © 2012 the Owner Societies.


Mudiyanselage K.,Brookhaven National Laboratory | An W.,Brookhaven National Laboratory | Yang F.,Brookhaven National Laboratory | Yang F.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2013

In this study the identity of diverse adsorption sites on a 5-7 Cu 2O/Cu(111) surface oxide structure has been identified. The 5-7 membered rings formed by a topological defect on stoichiometric Cu2O present different electronic structures from the originating hexagonal rings, as shown by combined bias dependent scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The adsorption of CO as a probe molecule on the 5-7 structure, studied using infrared reflection-absorption spectroscopy (IRRAS), shows the existence of special adsorption sites. By combining experimental and theoretical results, it is determined that CO molecules can be selectively confined inside the 7-membered oxide rings with internal dimensions of ∼0.85 nm, leading to a marked different adsorbate-substrate interaction than in either clean Cu(111) or Cu2O. The implication of these newly discovered sites on the chemistry of copper for catalytic reactions is discussed. © 2013 the Owner Societies.


Wang J.,Dalian University of Technology | Lu A.-H.,Dalian University of Technology | Li M.,CAS Dalian Institute of Chemical Physics | Zhang W.,Dalian University of Technology | And 3 more authors.
ACS Nano | Year: 2013

Thin porous alumina sheets have been synthesized using a lysine-assisted hydrothermal approach resulting in an extraordinary catalyst support that can stabilize Au nanoparticles at annealing temperatures up to 900 C. Remarkably, the unique architecture of such an alumina with thin sheets (average thickness ∼15 nm and length 680 nm) and rough surface is beneficial to prevent gold nanoparticles from sintering. HRTEM observations clearly showed that the epitaxial growth between Au nanoparticles and alumina support was due to strong interfacial interactions, further explaining the high sinter-stability of the obtained Au/Al2O3 catalyst. Consequently, despite calcination at 700 C, the catalyst maintains its gold nanoparticles of size predominantly 2 ± 0.8 nm. Surprisingly, catalyst annealed at 900 C retained the highly dispersed small gold nanoparticles. It was also observed that a few gold particles (6-25 nm) were encapsulated by an alumina layer (thickness less than 1 nm) to minimize the surface energy, revealing a surface restructuring of the gold/support interface. As a typical and size-dependent reaction, CO oxidation is used to evaluate the performance of Au/Al 2O3 catalysts. The results obtained demonstrated Au/Al2O3 catalyst calcined at 700 C exhibited excellent activity with a complete CO conversion at ∼30 C (T100% = 30 C), and even after calcination at 900 C, the catalyst still achieved its T 50% at 158 C. In sharp contrast, Au catalyst prepared using conventional alumina support shows almost no activity under the same preparation and catalytic test conditions. © 2013 American Chemical Society.


Qu Z.,Dalian University of Technology | Bu Y.,Dalian University of Technology | Qin Y.,Dalian University of Technology | Wang Y.,Dalian University of Technology | Fu Q.,CAS Dalian Institute of Chemical Physics
Applied Catalysis B: Environmental | Year: 2013

The effects of Ag on Mn/SBA-15 catalysts have been investigated in the toluene catalytic oxidation. The reactivity of catalysts is related closely to the Ag/Mn molar ratio, and the sample with 1:3 of Ag/Mn molar ratio exhibits the highest reactivity for toluene oxidation, with a complete conversion at 260°C. Based on the characterization results, it is found that Ag enters into MnO2 phase, and the Ag1.8Mn8O16 mixed phase forms. Meanwhile Ag leads to parts of MnO2 being transformed into Mn2O3. The Ag/Mn molar ratio has a strong influence on the molar ratio of the surface Mn4+ to Mn3+ and surface adsorbed oxygen (Oads) to lattice oxygen (Olatt) through the interaction between silver and MnOx. The coexistence of MnO2, Mn2O3, Ag1.8Mn8O16, and the strong interactions between Ag and Mn species exhibit a good synergetic interaction, which promotes the reducibility of catalysts and the formation of abundant active lattice oxygen, thus increasing the catalytic activity of toluene oxidation. And the formation of intermediate benzaldehyde should be closely link with the lattice oxygen of the Mn based catalyst. © 2012 Elsevier B.V.


Wang Y.-Q.,Nankai University | Wang Y.-Q.,Taiyuan University of Technology | Zhao T.,Nankai University | He X.-W.,Nankai University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2014

Herein, we synthesized a novel core-satellite CdTe/Silica/Au NCs hybrid sphere by covalently linking the separately synthesized highly fluorescent bovine serum albumin (BSA) stabilized gold nanoclusters (Au at BSA NCs) to the surface of the amino functionalized CdTe at SiO2 spheres by using the EDC chemistry. Numerous "satellites" of Au NCs were linked on the surface of the CdTe at SiO2 by the way of amide bonding. The synthesized dual-emission hybrid spheres were further characterized by the transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), UV-vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, photoluminescence (PL), etc. Finally, the CdTe/Silica/Au NCs hybrid spheres were developed as ratiometric fluorescence probe for the determination of Cu2+ with high sensitivity and selectivity. The fluorescence intensity ratio (F545nm/F655nm) of the probe against the concentration of Cu2+ showed a good linear relationship from 6.0×10-7molL-1 to 100.0×10-7molL-1. It showed an excellent reproducibility (0.67% relative standard deviation for 10 replicate measurements of Cu2+ at 40.0×10-7molL-1) and low detection limit (4.1×10-7molL-1). Furthermore, the ratiometric fluorescent probe was successfully applied in the determination of Cu2+ in vegetable samples with satisfactory results. © 2013 Elsevier B.V.


Zhou X.,Ewha Womans University | Zhou X.,Yanbian University | Lee S.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | Yoon J.,Ewha Womans University
Chemical Reviews | Year: 2015

The development of chemosensors has become an important research topic in supramolecular analytical chemistry, and as a result, it has attracted the continuous interest of academic researchers in chemistry and biology. The strategy of using pH indicators was first employed in the construction of fluorescent sensors for CO2. Another strategy was developed based on the chemical reaction between amine and CO2 in which CO2 is a weak electrophile that can react with an active basic amine to form corresponding carbamate salt and ammonium salt. On the basis of this chemical mechanism, a series of fluorescent sensors has been achieved to date. One approach is directly inserting an amine group into the conjugated fluorophore. Sessler and co-workers constructed two colorimetric- and fluorescence-based CO2 sensors based on N-fused compounds. Chang and colleagues developed the fluorescent sensor by using a commercial resorufin for sulfite detection. In this case, sulfite can selectively react with the carbonyl carbon of the levulinate and yield a tetrahedral intermediate. This corresponding intermediate can next undergo an intermolecular cyclization to release the free resorufin moiety, resulting in an up to 57-fold fluorescence enhancement with a detection limit of 49 μM in aqueous solution. Fluorescent sensors for NO containing o-phenylenediamine (OPD) moieties and fluorophores have been developed by Nagano?s group and shown to be highly effective for visualizing this gas in vitro and in vivo.


Zhu Y.,Central South University | Yu L.,Central South University | Wang X.,CAS Dalian Institute of Chemical Physics | Zhou Y.,Central South University | Ye H.,Central South University
Catalysis Communications | Year: 2013

Immobilization on a structured substrate is a prerequisite for exploiting practical applications for graphene as a catalytic support. Here we report that graphene oxide (GO) nanosheets can readily form a stable coating on a cordierite honeycomb substrate without any need of stabilizers. FT-IR and 1H NMR characterization revealed that GO nanosheets were probably immobilized on the cordierite surface by hydrogen bonding. TEM analysis indicated that palladium particles loaded on the graphene/cordierite exhibited a uniform size of less than 5 nm, which led to 4 times higher activity for styrene hydrogenation than that loaded on the cordierite. © 2013 . Published by Elsevier B.V. All rights reserved.


Xu W.,National University of Singapore | Fan H.,CAS Dalian Institute of Chemical Physics | Wu G.,Dalian National Laboratory for Clean Energy | Chen P.,Dalian National Laboratory for Clean Energy
New Journal of Chemistry | Year: 2012

Lithium amidoborane (LiNH 2BH 3) and ammonia borane (NH 3BH 3) reduce aromatic aldehydes in tetrahydrofuran (THF) through two different pathways. LiNH 2BH 3 only transfers hydridic hydrogen on boron to aldehydes through a hydroboration process to achieve lithium aminoborate; ammonia borane, on the other hand, transfers both protic and hydridic hydrogens on N and B, respectively, to aldehydes to directly achieve corresponding alcohols. Mechanistic investigations confirm that protic H(N) and hydridic H(B) of ammonia borane participate in the reduction, in which the dissociation of both B-H and N-H bonds is likely to be involved in the rate-determining step. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.


Liu Y.-H.,Bohai University | Liu Y.-H.,CAS Dalian Institute of Chemical Physics | Lan S.-C.,Bohai University | Li C.-R.,Bohai University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

In this work, the dynamics of hydrogen bonds (as well as the hydrogen-bonded wire) in excited-state tautomerization of 7- hydroxyquinoline·(NH3)3 (7HQ· (NH 3)3) cluster has been investigated by using timedependent density functional theory (TDDFT). It shows that upon an excitation, the hydrogen bond between -OH group in 7-hydroxyquinoline (7HQ) and NH3 moiety would extremely strengthened in S1 state, which could effectively facilitate the releasing of the proton from the phenolic group of 7HQ moiety to the hydrogen-bonded wire and the forming an Eigen-like cationic wire (NH 3 · · · NH4+ ···NH3) in the cluster. To fulfill the different optimal angles of NH4+ in the wire, a wagging motion of hydrogen-bonded wire would occur in excited state. Moreover, the wagging motion of the hydrogen-bonded wire would effectively promote excited-state proton transfer reaction. As the results, an excited-state multiple proton transfer (ESMPT) mechanism containing two concerted and asymmetrical processes has been proposed for the proton transfer dynamics of 7HQ·(NH3) 3 cluster. © 2013 Elsevier B.V. All rights reserved.


Czako G.,Emory University | Shuai Q.,Academia Sinica, Taiwan | Shuai Q.,CAS Dalian Institute of Chemical Physics | Liu K.,Academia Sinica, Taiwan | Bowman J.M.,Emory University
Journal of Chemical Physics | Year: 2010

The effects of the reactant bending excitations in the F+CHD3 reaction are investigated by crossed molecular beam experiments and quasiclassical trajectory (QCT) calculations using a high-quality ab initio potential energy surface. The collision energy (Ec) dependence of the cross sections of the F+CHD3 (vb =0,1) reactions for the correlated product pairs HF (v′) + CD3 (v2 =0,1) and DF (v′) + CHD2 (v4 =0,1) is obtained. Both experiment and theory show that the bending excitation activates the reaction at low Ec and begins to inactivate at higher Ec. The experimental F+CHD3 (vb =1) excitation functions display surprising peak features, especially for the HF (v′ =3) + CD3 (v2 =0,1) channels, indicating reactive resonances (quantum effects), which cannot be captured by quasiclassical calculations. The reactant state-specific QCT calculations predict that the v5 (e) bending mode excitation is the most efficient to drive the reaction and the v6 (e) and v5 (e) modes enhance the DF and HF channels, respectively. © 2010 American Institute of Physics.


Zhu Y.,Anshan Normal University | Zhang B.,CAS Shenyang Institute of Metal Research | Liu X.,CAS Dalian Institute of Chemical Physics | Wang D.-W.,University of New South Wales | Su D.S.,CAS Shenyang Institute of Metal Research
Angewandte Chemie - International Edition | Year: 2014

Non-precious Fe/N co-modified carbon electrocatalysts have attracted great attention due to their high activity and stability in oxygen reduction reaction (ORR). Compared to iron-free N-doped carbon electrocatalysts, Fe/N-modified electrocatalysts show four-electron selectivity with better activity in acid electrolytes. This is believed relevant to the unique Fe-N complexes, however, the Fe-N structure remains unknown. We used o,m,p-phenylenediamine as nitrogen precursors to tailor the Fe-N structures in heterogeneous electrocatalysts which contain FeS and Fe3C phases. The electrocatalysts have been operated for 5000 cycles with a small 39 mV shift in half-wave potential. By combining advanced electron microscopy and Mössbauer spectroscopy, we have identified the electrocatalytically active Fe-N6 complexes (FeN6, [FeIII(porphyrin)(pyridine)2]). We expect the understanding of the FeN6 structure will pave the way towards new advanced Fe-N based electrocatalysts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Shen Z.,Tongji University | Shen Z.,CAS Dalian Institute of Chemical Physics | Zhang Y.,Tongji University | Jin F.,Shanghai JiaoTong University
RSC Advances | Year: 2012

A hydrothermal method for the hydrogen-transfer reduction of CO 2 or NaHCO 3 is presented. This process uses glycerine as a reducing agent, which is ultimately converted to lactate, and can convert NaHCO 3 into formate in about a 90% yield with respect to the initial amount of glycerine. © 2012 The Royal Society of Chemistry.


Han F.,Dalian University of Technology | Li W.-C.,Dalian University of Technology | Li M.-R.,CAS Dalian Institute of Chemical Physics | Lu A.-H.,Dalian University of Technology
Journal of Materials Chemistry | Year: 2012

A tubular composite, including ultrafine SnO 2 particles encapsulated in ordered tubular mesoporous carbon with thin walls and high pore volume, is fabricated through the in situ hydrolysis method. It is observed that up to 80 wt% of SnO 2 particles with size between 4-5 nm are highly dispersed and homogeneously encapsulated in the mesopore channels and no bulky aggregates are visible. The tubular composite exhibits a considerably high reversible capacity of 978 mA h g -1 and a high initial efficiency of 71% at a current density of 200 mA g -1 between 0.005-3 V. Its reversible capacity even increases up to 1039 mA h g -1 after 100 cycles, which is much higher than the conventional theoretical capacity of SnO 2 (782 mA h g -1), meanwhile, it also displays fast discharge/charge kinetics at a high current density of 1500 mA g -1. The excellent electrochemical performance is ascribed to its unique mesostructure by recruiting tubular mesoporous carbon with thin carbon walls (∼2 nm) and high pore volume (2.16 cm 3 g -1). This tubular nanostructure provides confined nanospace for hosting immobilized ultrafine SnO 2 with high loading, compensates volume expansion of SnO 2, warrants efficient contact between nanoparticles and carbon matrix before and after Li + insertion. We believe this special structure model might be extended for the fabrication of other cathode and anode electrode materials, to achieve high performance LIBs. © 2012 The Royal Society of Chemistry.


Xu X.,Northwest University, China | Wang X.,Northwest University, China | Li Y.,Dalian University of Technology | Wang Y.,Northwest University, China | Yang L.,CAS Dalian Institute of Chemical Physics
Nucleic Acids Research | Year: 2012

Nano-scale particles have attracted a lot of attention for its potential use in medical studies, in particular for the diagnostic and therapeutic purposes. However, the toxicity and other side effects caused by the undesired interaction between nanoparticles and DNA/RNA are not clear. To address this problem, a model to evaluate the general rules governing how nanoparticles interact with DNA/RNA is demanded. Here by, use of an examination of 2254 native nucleotides with molecular dynamics simulation and thermodynamic analysis, we demonstrate how the DNA/RNA native structures are disrupted by the fullerene (C60) in a physiological condition. The nanoparticle was found to bind with the minor grooves of double-stranded DNA and trigger unwinding and disrupting of the DNA helix, which indicates C60 can potentially inhibit the DNA replication and induce potential side effects. In contrast to that of DNA, C60 only binds to the major grooves of RNA helix, which stabilizes the RNA structure or transforms the configuration from stretch to curl. This finding sheds new light on how C60 inhibits reverse transcription as HIV replicates. In addition, the binding of C60 stabilizes the structures of RNA riboswitch, indicating that C60 might regulate the gene expression. The binding energies of C60 with different genomic fragments varies in the range of -56 to -10 kcal mol-1, which further verifies the role of nanoparticle in DNA/RNA damage. Our findings reveal a general mode by which C60 causes DNA/RNA damage or other toxic effects at a systematic level, suggesting it should be cautious to handle these nanomaterials in various medical applications. © 2012 The Author(s).


Khan A.L.,Catholic University of Leuven | Klaysom C.,Catholic University of Leuven | Gahlaut A.,Catholic University of Leuven | Li X.,CAS Dalian Institute of Chemical Physics | Vankelecom I.F.J.,Catholic University of Leuven
Journal of Materials Chemistry | Year: 2012

Mixed matrix membranes (MMMs) composed of sulfonated aromatic poly(ether ether ketone) (SPEEK) and -SO 3 functionalized mesoporous MCM-41 were prepared by the solution casting method. A SPEEK polymer with a fixed degree of sulfonation was used for membrane synthesis. CO 2 permeation data and SEM images of the synthesized MMMs suggest that the functionalized fillers adhered well to the polymer matrix. Gas permeation tests indicated that the addition of functionalized MCM-41 to the polymer matrix increased both the gas permeability and selectivity. The highest selectivities obtained here for CO 2/N 2 and CO 2/CH 4 were 40.46 and 22.86 (at a CO 2 permeability of 21.04 Barrer), respectively. In order to initiate the evaluation of the practical commercial viability of these membranes, they were tested under different operating pressures and temperatures. © 2012 The Royal Society of Chemistry.


Cao X.,Nanjing University of Science and Technology | Jiang S.,Nanjing University of Science and Technology | Yu C.,Nanjing University of Science and Technology | Wang Y.,Nanjing University of Science and Technology | And 3 more authors.
Optics Express | Year: 2014

We present a theoretical investigation of high-order harmonic generation in spatially inhomogeneous two-color laser fields by solving three dimensional time dependent Schrödinger equation. The cutoff in the harmonic spectra can be significantly extended by means of our proposed method (i.e., from helium interacting with the plasmon-enhanced two-color laser fields), and an ultrabroad supercontinuum up to 1.5 keV is generated by selecting proper carrier-envelope phase of the controlling field. Moreover, classical trajectory extraction, time-dependent ionization and recombination rates, and time-frequency analyses are used to explain the generation of this ultrabroadband supercontinuum. As a result, an isolated 8.8 attosecond pulse can be generated directly by the superposition of the supercontinuum harmonics. © 2014 Optical Society of America.


Gao R.,Nankai University | Kong X.,Nankai University | Wang X.,Nankai University | He X.,Nankai University | And 3 more authors.
Journal of Materials Chemistry | Year: 2011

A general method to prepare thin, molecularly imprinted polymer (MIP) coatings on magnetic Fe3O4 nanoparticles (NPs) with a uniform core-shell structure for the recognition and enrichment of protein was developed. Four proteins (bovine serum albumin (BSA, pI = 4.9), bovine hemoglobin (BHb, pI = 6.9), bovine pancreas ribonuclease A (RNase A, pI = 9.4) and lysozyme (Lyz, pI = 11.2)) with different isoelectric points were chosen as the templates. The magnetic protein-MIPs were synthesized by combining surface imprinting and sol-gel techniques. The morphology, adsorption and recognition properties of the magnetic molecularly imprinted NPs were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy and through the use of a vibrating sample magnetometer (VSM). In comparison with the use of Lyz, BSA and RNase A as template proteins, BHb-imprinted Fe 3O4 showed the best imprinting effect and the highest adsorption capacity among the four proteins. The as-prepared Fe 3O4@BHb-MIPs NPs with a mean diameter of 230 nm were coated with an MIP shell that was 10 nm thick, which enabled the Fe 3O4@BHb-MIPs to easily reach adsorption equilibrium. A high magnetic saturation value of 25.47 emu g-1 for Fe 3O4@BHb-MIPs NPs was obtained, which endowed the adsorbent with the convenience of magnetic separation under an external magnetic field. The resultant Fe3O4@BHb-MIPs NPs could not only selectively extract a target protein from mixed proteins but also specifically capture the protein BHb from a real sample of bovine blood. In addition, different batches of magnetic MIPs showed good reproducibility and reusability for at least six repeated cycles. © 2011 The Royal Society of Chemistry.


Zheng H.,Zhejiang University of Technology | Hu D.,Zhejiang University of Technology | Zhang L.,CAS Dalian Institute of Chemical Physics | Ma C.,Zhejiang University of Technology | Rufford T.,University of Western Australia
Minerals Engineering | Year: 2012

Thiol functionalized mesoporous silica (TFMS) with ordered hexagonal pore structure was fabricated by one-step synthesis pathway. The selective adsorption for precious metals was investigated using single component and binary adsorption solutions. The TFMS displayed strong affinity for gold or platinum in specific conditions with a large adsorption capacity, and showed a high selectivity in the binary solutions within 30 min. Furthermore, gold and platinum could be totally recovered by elution with 5 M HCl and 0.7 M thiourea-2 M HCl, respectively. © 2012 Elsevier Ltd. All rights reserved.


Wang M.,Beijing Institute of Technology | Liu X.,CAS Dalian Institute of Chemical Physics | Cao C.,Beijing Institute of Technology | Shi C.,Beijing Institute of Technology
RSC Advances | Year: 2012

Cu-In-S ternary nanocrystals (NCs), with an average size of less than 10 nm, were synthesized in an aqueous solution containing bovine serum albumin (BSA). X-Ray powder diffraction (XRD) and selected-area electron diffraction (SAED) analyses showed that these NCs featured a roquesite structure. The composition of the NCs could be adjusted by controlling the molar ratio of the starting Cu/In precursors in the reaction solution, which led to a tunable band gap ranging from 1.48 eV to 2.30 eV. Cytotoxicity testing showed that the BSA-stabilized Cu-In-S NCs had little effect on the cell viability, which suggested that they are user-friendly and environmentally benign. With low cost, minimal energy input and environmental impact, this simple approach shows great potential for industrial applications. © 2012 The Royal Society of Chemistry.


Sun Q.,Jilin University | Wang N.,Jilin University | Xi D.,Jilin University | Yang M.,CAS Dalian Institute of Chemical Physics | Yu J.,Jilin University
Chemical Communications | Year: 2014

Using an organosilane surfactant as the mesopore director, hierarchical porous silicoaluminophosphate SAPO-34 is obtained as an assembly of nanocrystallites intergrown into cubic micrometer-sized crystals, which show excellent performance in MTO reactions with a remarkably prolonged catalyst lifetime and enhanced selectivity of ethylene and propylene compared to the conventional microporous SAPO-34. This journal is © the Partner Organisations 2014.


Hou J.,Virginia Polytechnic Institute and State University | Shao Y.,Pacific Northwest National Laboratory | Ellis M.W.,Virginia Polytechnic Institute and State University | Moore R.B.,Virginia Polytechnic Institute and State University | Yi B.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems. This journal is © the Owner Societies.


Wang X.,Tufts University | Wang X.,CAS Dalian Institute of Chemical Physics | Kaplan D.L.,Tufts University
Biomaterials | Year: 2012

A hormone-responsive 3D human tissue-like culture system was developed in which human primary mammary epithelial cells (MECs) were co-cultured with two types of predominant mammary stromal cells on silk protein scaffolds. Silk porous scaffolds with incorporated extracellular matrix provided a compatible environment for epithelial structure morphogenesis and differentiation. The presence of stromal cells promoted MEC proliferation, induced both alveolar and ductal morphogenesis and enhanced casein expression. In contrast, only alveolar structures were observed in monocultures. The alveolar structures generated from the heterotypic cultures in vitro exhibited proper polarity similar to human breast tissue in vivo. Consistent with their phenotypic appearance, more functional differentiation of epithelial cells was also observed in the heterotypic cultures, where casein-α and -β mRNA expression were increased significantly. Additionally, this 3D multicellular culture model displayed an estrogen-responsive physiologically relevant response, evidenced by enhanced cell proliferation, aberrant morphology, changes in gene expression profile and few polarized lumen structures after estrogen treatment. This culture system offers an excellent opportunity to explore the role of cell-cell and cell-substrate interactions during mammary gland development, the consequences of hormone receptor activation on MEC behavior and morphogenesis, as well as their alteration during neoplastic transformation in human breast tissue. © 2012 Elsevier Ltd.


Zhang Z.,South-Central University for Nationalities | Liu B.,South-Central University for Nationalities | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhao Z.,Dalian National Laboratory for Clean Energy
Carbohydrate Polymers | Year: 2012

Conversion of fructose into 5-hydroxymethylfurfural (HMF) catalyzed by Germanium(IV) chloride was studied in Dimethyl sulfoxide (DMSO) and [Bmim]Cl system at room temperature. The structure of ionic liquids and the ratio of ionic liquids to DMSO had a remarkable effect on this new catalytic system. The results indicated that 1-n-butyl-3-methylimidazolium chloride ([Bmim]Cl) was favorable for the dehydration of fructose to HMF. Under optimal conditions, a high HMF yield in 70% was obtained at 25°C. In addition, it was also proved that there was a synergistic effect between the cation and anion of [Bmim]Cl on the dehydration of fructose to HMF by designed experiments. Finally, a possible mechanism for the dehydration of fructose to HMF was proposed. © 2012 Elsevier Ltd. All rights reserved.


Sun H.,Lanzhou University of Technology | Li A.,Lanzhou University of Technology | Zhu Z.,Lanzhou University of Technology | Liang W.,Lanzhou University of Technology | And 3 more authors.
ChemSusChem | Year: 2013

Highly porous activated carbon with a large surface area and pore volume was synthesized by KOH activation using commercially available activated carbon as a precursor. By modification with polydimethylsiloxane (PDMS), highly porous activated carbon showed superhydrophobicity with a water contact angle of 163.6°. The changes in wettability of PDMS- treated highly porous activated carbon were attributed to the deposition of a low-surface-energy silicon coating onto activated carbon (confirmed by X-ray photoelectron spectroscopy), which had microporous characteristics (confirmed by XRD, SEM, and TEM analyses). Using an easy dip-coating method, superhydrophobic activated carbon-coated sponges were also fabricated; those exhibited excellent absorption selectivity for the removal of a wide range of organics and oils from water, and also recyclability, thus showing great potential as efficient absorbents for the large-scale removal of organic contaminants or oil spills from water. Supersponge, save the world! Superhydrophobic activated carbon-coated sponges show good selectivity, recyclability, and absorbencies ranging from 2695 to 8586 wt % for a wide range of organic solvents and oils. These materials may have useful applications especially in the fields of oil-spill cleanup and water treatment. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yang Z.,CAS Dalian Institute of Chemical Physics | Yang Z.,CAS Zhengzhou Research Institute | Hu J.,CAS Zhengzhou Research Institute | Zhao M.,CAS Zhengzhou Research Institute
Carbohydrate Polymers | Year: 2011

Inulin-type oligosaccharides with different degree of polymerization (DP) were isolated from the traditional Chinese medicine: Morina officinalis by size-exclusion chromatography, and their purities were determined by HPLC-ELSD equipped with cyclodextrin-bond column. Through analysis, the purities of obtained inulin-type oligosaccharides were higher more than 98% by one-step process. The structures of inulin-type oligosaccharides were confirmed by a combination of NMR, MS as well as comparison with already existing NMR data. Using d-fructose and the isolated inulin-type oligosaccharides as standards, a determination method of monosaccharide and inulin-type oligosaccharides in Morinda officinalis was first developed and validated. The validated method was successfully applied to analyze monosaccharide and oligosaccharides in three types of roots of M. officinalis and provided a new basis of assessment on quality of M. officinalis. © 2010 Elsevier Ltd. All rights reserved.


Yang X.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

In the last decade or so, the H-atom Rydberg tagging time-of-flight (HRTOF) technique has made a significant impact in the study of state-to-state reaction dynamics, and especially in the study of transition state dynamics of elementary chemical reactions and quantum state resolved dynamics of molecular photodissociation of important molecules. In this perspective, we will discuss mainly the state-to-state dynamics of three important elementary reactions: H + H2, O(1D) + H2 and F + H2 that have been studied in our laboratory in recent years using the HRTOF method. In addition, we will also mention briefly the experimental results of other reactive systems. In the end, we will also present a brief research outlook in the study of molecular reaction dynamics using this powerful experimental method. © 2011 the Owner Societies.


Liu F.,CAS Research Center for Eco Environmental Sciences | He H.,CAS Research Center for Eco Environmental Sciences | Zhang C.,CAS Research Center for Eco Environmental Sciences | Feng Z.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Applied Catalysis B: Environmental | Year: 2010

A novel iron titanate catalyst prepared by conventional co-precipitation method showed excellent activity, N2 selectivity and H2O/SO2 durability in the selective catalytic reduction (SCR) of NO with NH3. The influence of precursors and preparation methods on the catalyst structure and activity was comprehensively investigated. Iron titanate catalyst prepared using titanium sulfate as Ti precursor was favorable for the high activity and selectivity, comparing with that using titanium tetrachloride as precursor and Fe2O3/TiO2 loaded type catalyst. Especially, the best iron titanate catalyst showed good activity in a temperature window of 200-350 °C with the NOx conversion above 90% in the absence of H2O, which was 50-150 °C lower than those of other known Fe-based catalysts. Iron titanate crystallite with specific Fe-O-Ti structure was found to be the main active phase. The interaction between iron and titanium species in atomic scale led to an enhancement of oxidative ability of Fe3+, which was beneficial to the SCR reaction. © 2010 Elsevier B.V. All rights reserved.


Zhang X.,Henan Normal University | Liu Y.,Henan Normal University | Wang Y.,CAS Dalian Institute of Chemical Physics
Theoretical Chemistry Accounts | Year: 2014

The conversion of cholesterol to pregnenolone is a physiologically essential process which initiates with two sequential hydroxylation processes catalyzed by cytochrome P450 side-chain cleavage enzyme (P450SCC). Extensive efforts have been exerted; however, the mechanistic details remain obscure. In this work, we employed the dispersion-corrected density functional theoretical (DFT-D) calculations to investigate the mechanistic details of such hydroxylation processes. Calculated results reveal that the active intermediate Compound I (CpdI) of P450SCC hydroxylates cholesterol efficiently, which coincides with previous spectrometric observations. The hydrogen bond effect of water molecule within the active site lowers the energy barrier significantly. Intriguingly, the adjacent hydrogen bond (H-bond) between the hydroxyl group of the substrate and the oxo group of CpdI in the second hydroxylation affects the H-abstraction significantly. Such H-bond was weakened during the C-H bond activation process, increasing the energy barriers by approximately 2 kcal/mol, which is different to the intermolecular H-bond effect of water903 found by Shaik et al. that decreases the barrier by about 4 kcal/mol. Such adjacent H-bond also affects the transition state by bending the alignment of the C-H-O moiety, and consequently lowering the kinetic isotope effect values. Besides, a series of DFT-D calculations (Grimme's D2, D3-zero, and D3-BJ methods) were performed and accessed to find out an appropriate protocol for H-bond containing hydroxylation process. Our results show that DFT-D single-point energies (SPE) based on geometries optimized with non-dispersion-corrected DFT varies drastically and sometime presents unreasonable results. DFT-D SPE calculations on DFT-D optimized geometries present stable and reasonable results. © Springer-Verlag Berlin Heidelberg 2014.


Li G.-L.,Nanjing University | Li G.-L.,CAS Dalian Institute of Chemical Physics | Yin Z.,Nanjing University
Physical Chemistry Chemical Physics | Year: 2011

The electronic and optical properties of InMO4 (M = V, Nb, Ta) photocatalysts are studied using first-principles calculations. For all InMO4, the calculated band gaps are larger than the measured optical gaps, indicating the existence of sub-bandgap transitions. Impurity states and excitons are considered to interpret the characteristic absorption onsets in the measured UV-visible diffuse reflection spectra. The novel visible-light-active water-splitting photocatalytic properties of InMO4 are related to the sub-bandgap transitions. Correlation between the impurity states and the photocatalytic activities is discussed for InMO4via the conventional mechanism of photocatalytic water-splitting on semiconductors. An excitonic mechanism analogous to Photosystem II in plant photosynthesis is also proposed for the photocatalytic water-splitting process on InMO4. © 2011 the Owner Societies.


Xiahou C.,University of Manchester | Connor J.N.L.,University of Manchester | Zhang D.H.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

State-of-the-art differential cross sections (DCSs) have been reported by Wang et al. [Proc. Nat. Acad. Sci. (U.S.), 2008, 105, 6227] for the state-to-state F + H2 → FH + H reaction using fully quantum-state-selected crossed molecular beams. We theoretically analyze the angular scattering of this reaction, in order to quantitatively understand the physical content of structure in the DCSs. Three transitions are studied, v i = 0, ji = 0, mi = 0 → vf = 3, jf = 0, 1, 2, mf = 0 at a translational energy of 0.04088 eV, where v, j, m are the vibrational, rotational and helicity quantum numbers respectively for the initial and final states. The input to our analyses consists of accurate quantum scattering (S) matrix elements computed for the Fu-Xu-Zhang potential energy surface, as used by Wang et al. in a computational simulation of their experimental DCSs. We prove that the pronounced peak at forward angles observed in the experimental and simulated DCSs for all three transitions is a glory. At larger angles, it is demonstrated that the 000 → 300 and 000 → 310 DCSs both possess a broad farside rainbow, which is accompanied by diffraction oscillations. We confirm the conjecture of Wang et al. that these diffraction oscillations arise from nearside-farside (NF) interference. We find that the reaction is N dominant for all three transitions. The theoretical techniques used to analyze the angular scattering include uniform semiclassical theories of glory and of rainbow scattering. We also make the first application of a semiclassical formula that is uniform for both glory + rainbow scattering. In addition, structure in the DCSs is analyzed using NF theory and local angular momentum theory, in both cases with three resummations of the partial wave series for the scattering amplitude. We make the first explicit application of the Thiele rational interpolation formula to extract the position and residue of the leading Regge pole from a set of S matrix elements, thereby making contact with complex angular momentum theories of DCSs, which interpret the angular scattering in terms of Regge resonances. Our calculations complement the exit-valley vibrationally-adiabatic analysis of Wang et al. © the Owner Societies 2011.


Wu J.,Hong Kong University of Science and Technology | Kodzius R.,Hong Kong University of Science and Technology | Xiao K.,Hong Kong University of Science and Technology | Qin J.,CAS Dalian Institute of Chemical Physics | Wen W.,Hong Kong University of Science and Technology
Biomedical Microdevices | Year: 2012

In this paper, we report the construction of a polymerase chain reaction (PCR) device for fast amplification and detection of DNA. This device consists of an interchangeable PCR chamber, a temperature control component as well as an optical detection system. The DNA amplification happens on an interchangeable chip with the volumes as low as 1.25 μl, while the heating and cooling rate was as fast as 12.7°C/second ensuring that the total time needed of only 25 min to complete the 35 cycle PCR amplification. An optimized PCR with two-temperature approach for denaturing and annealing (T d and T a) of DNA was also formulated with the PCR chip, with which the amplification of male-specific sex determining region Y (SRY) gene marker by utilizing raw saliva was successfully achieved and the genetic identification was in-situ detected right after PCR by the optical detection system. © 2011 Springer Science+Business Media, LLC.


Liu Y.,Brandeis University | Liu Y.,CAS Dalian Institute of Chemical Physics | Provencher B.A.,Brandeis University | Bartelson K.J.,Brandeis University | Deng L.,Brandeis University
Chemical Science | Year: 2011

A class of easily accessible and readily tunable chiral phase transfer catalysts based on 6′-OH cinchonium salts was found to efficiently catalyze an unprecedented highly enantioselective Darzens reaction of α-chloro ketones and aldehydes, which directly produces optically active chiral epoxides from readily available carbonyl compounds. © The Royal Society of Chemistry 2011.


Zhang H.,CAS Dalian Institute of Chemical Physics
ECS Transactions | Year: 2013

Vanadium flow battery (VFB) as one kind of energy storage techniques is rather suitable for large scale energy storage due to its features like long life time, active thermal management as well as the independence of energy and power ratings. Dalian Institute of Chemical Physics has devoted to VFB researches for more than 10 years. In this presentation, we will summarize the R&D status of VFB in DICP from materials to system integration. © The Electrochemical Society.


Dong H.,Liaoning Normal University | Zhou X.,CAS Dalian Institute of Chemical Physics | Jiang C.,Liaoning Normal University
Theoretical Chemistry Accounts | Year: 2012

We report on a quantum-chemical study of the electronic and optical properties of a series of β, β′-edge-fused zinc porphyrin with different aromatic rings, in order to design efficient sensitizers for dye-sensitized solar cells (DSSCs). Our calculations found that the replacement of quinoxaline moiety in ZnQMA (having high power conversion efficiency η of 6. 3%) with other aromatic rings decreases the HOMO-LUMO energy gap mainly due to destabilization of the HOMO level. For all of the investigated compounds, the reorganization energies of electron and hole are in the same order of magnitude as and similar to those of ZnQMA. The absorption spectra in both Soret and Q bands for most of the considered molecules exhibit red shifts to some extent with respect to that of ZnQMA. In the simulated dye-sensitized TiO 2 systems, the bidentate adsorption mode of porphyrin derivatives is computed to be energetically favored compared to the monodentate one, which well confirms the experimental results observed by X-ray photoelectron spectroscopy. The slightly shorter Ti-O bond lengths calculated for D-TiO 2 systems point toward a stronger interaction of the dye with the titania surface compared to ZnQMA-TiO 2 systems. Our calculation indicates that the designed molecule D is promising to challenge the current photoelectric conversion efficiency record 6. 3% of ZnQMA. © 2012 Springer-Verlag.


Kim H.N.,Ewha Womans University | Lee E.-H.,Gyeongsang National University | Xu Z.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Biomaterials | Year: 2012

G-quadruplexes, formed of four stranded guanine bases stabilized by monovalent cations, serve important role in cancer cell growth and control gene expression in telomere. Since there are various types of quadruplex structures, rapid and simple screening methods with high selectivity, sensitivity and nontoxicity are required for understanding about the biological roles of quadruplex DNA as well as in designing therapeutics. Herein, we report a pyrene-imidazolium derivative, JY-1, which can with high selectivity recognize G-quadruplex using fluorescence and NMR spectroscopy. This is the first example based on the imidazolium derivative, which can detect the G-quadruplex directly to utilize the excimer/monomer emission change in pyrene fluorophore. The selectivity of strong binding to a specific sequence can allow for quadruplex sensing and the detection method presented here is very simple, using fluorescence and NMR study. Also, the groove binding characteristic of JY-1 to the G-quadruplex has a relatively low nonspecific toxicity and the structure-specific differences in fluorescent character between DNA duplex and G-quadruplex may offer more discovery and application in biological study. © 2011 Elsevier Ltd.


Hu J.,CAS Dalian Institute of Chemical Physics
Journal of Physical Chemistry C | Year: 2013

Graphene oxide (GO) is successfully exploited as support, loading titanium for catalytic propylene epoxidation. By means of DFT exploration, it is found that atomic Ti has thermodynamical tendency to coordinate with multiple hydroxyl, replacing hydrogen and forming stable tripodal configuration above the GO basal plane. Under reactive conditions, an extra two OHs are also bonded above Ti, and a key intermediate is generated. On the basis of this substance, catalytic cycle composed of H2O2 activation and formation of peroxo, attack of propylene and formation of additive compound, as well as final cyclization and formation of epoxide are successfully constructed. The calculated overall apparent barrier is 0.66 eV, comparable to that of zeolites and less than that of polyoxometalates, indicating the potential application under mild conditions. © 2013 American Chemical Society.


Yin Z.,Tianjin Polytechnic University | Chi M.,Oak Ridge National Laboratory | Zhu Q.,China National Institute of Clean and Low Carbon Energy | Ma D.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Journal of Materials Chemistry A | Year: 2013

Monodispersed bimetallic PdAu nanoparticles with controlled composition are prepared by an emulsion-assisted synthetic strategy with ternary metal precursors in the surfactants of oleic acid and oleylamine. The PdAu nanoparticles are loaded on a carbon support, and their electrocatalytic activities are tested for methanol oxidation in alkaline media. The bimetallic PdAu nanoparticles show superior electrocatalytic activities for methanol oxidation compared with the pure Pd nanoparticles prepared by the same method. The most active Pd30Au70 nanoparticles, with significantly low Pd content, even show remarkably higher activities than the commercial Pt/C catalyst. Various characterization techniques such as TEM, XPS and UV-vis are applied to study the nature of the catalysts. It is concluded that the increased activity is dependant on the unique Pd-rich shell and Au-rich core structure of such bimetallic PdAu particles as well as the nature of the Pd species on the catalyst surface. © 2013 The Royal Society of Chemistry.


Zhou Y.-C.,Lanzhou University | Zhang H.-L.,Lanzhou University | Deng W.-Q.,CAS Dalian Institute of Chemical Physics
Nanotechnology | Year: 2013

Doping a graphene sheet with different atoms is a promising method for tuning its electronic properties. We report a first-principle investigation on the electronic properties of N, B, S, Al, Si or P doped graphene. It is revealed that the doped graphene can show an interesting physical regularity, which can be described by a simple 3N rule: a doped graphene has a zero gap or a neglectable gap at the Dirac point when its primitive cell is 3N × 3N (N is an integer), otherwise there is a gap tunable by the dopant concentration. This unique 3N rule provides a useful guideline for the design of doped graphene for electronic applications. © 2013 IOP Publishing Ltd.


Xiao J.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2012

The unprecedented cooperative systems involving a diarylprolinol silyl ether with various Lewis acids have been found to effect the highly enantioselective intermolecular α-alkylation of aldehydes. A wide variety of aldehydes and alcohols can be transformed into the desired highly functionalized aldehydes in high yields, excellent enantioselectivities, and good diastereoselectivities at room temperature under mild conditions. © 2012 American Chemical Society.


Chen W.,Florida International University | Fan Z.,Florida International University | Gu L.,Max Planck Institute for Intelligent Systems (Stuttgart) | Bao X.,CAS Dalian Institute of Chemical Physics | Wang C.,Florida International University
Chemical Communications | Year: 2010

The confinement within carbon nanotubes (CNTs) improves the electrochemical reversibility of CNT-confined MnO2 nanoparticles and benefits their capacitive enhancement, which exhibit a specific capacitance of 225 F g -1 for the composites and MnO2 normalized capacitance as high as 1250 F g-1. © 2010 The Royal Society of Chemistry.


Zhang X.-B.,Hefei University of Technology | Tong H.-W.,Hefei University of Technology | Liu S.-M.,Hefei University of Technology | Yong G.-P.,Hefei University of Technology | And 2 more authors.
Journal of Materials Chemistry A | Year: 2013

Significant progress has recently been made in the synthesis of Fe 3O4@C nanospheres with uniform, monodisperse and tunable carbon shells. Fe3O4@C nanospheres were obtained by directly carbonizing Fe3O4@polymer which was synthesized by a versatile and economical Stöber method with resorcinol and formaldehyde as precursors. The synthesis conditions in the formation of Fe 3O4@polymer were systematically investigated. It was found that the yield of the Fe3O4@polymer is highly influenced by the concentration of ammonium hydroxide, and the monodispersity is mainly affected by the concentration of ammonium hydroxide and the citrate group sites outside the surfaces of the Fe3O4 nanospheres. Interestingly, carbonization of Fe3O4@polymer at high temperature makes the grain sizes of Fe3O4 in Fe 3O4@C samples larger than those in the Fe 3O4 sample, which makes the saturation magnetization value for the Fe3O4@C samples higher than those of common obtained materials. The adsorption performance of Fe3O4@C for anthracene was tested both in water and in cyclohexane solution; it shows fast adsorption rates (about 1 h to reach equilibrium in water and 3 h in cyclohexane solution) and high adsorption capacities (31.5 mg g-1 in water and 2 mg g-1 in cyclohexane solution), which are ascribed to its high uniformity and monodispersity. These make Fe3O4@C an ideal adsorption and enrichment material, especially for polycyclic aromatic hydrocarbons in water and in organic solvents. This journal is © The Royal Society of Chemistry 2013.


Zhang Z.,South-Central University for Nationalities | Liu B.,South-Central University for Nationalities | Zhao Z.K.,CAS Dalian Institute of Chemical Physics
Starch/Staerke | Year: 2012

Conversion of carbohydrates into HMF in ionic liquids (ILs) catalyzed by HfCl4 has been investigated in search of an efficient and environment-friendly process. The structure of ILs, catalyst loading, and reaction temperature had remarkable effects on this new catalytic system. Under optimal conditions, HMF yield up to 77.5% was obtained from fructose in 30 min at 100°C. Moderate yields of HMF were also obtained from aldohexose such as glucose, cellobiose, even cellulose. Furthermore, a possible mechanism for carbohydrates conversion into HMF catalyzed by HfCl4 was proposed according to the configuration of valence shell of Hf. This work provides a meaningful method for the conversion of carbohydrates into fine chemicals. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu B.,South-Central University for Nationalities | Zhang Z.,South-Central University for Nationalities | Zhao Z.K.,CAS Dalian Institute of Chemical Physics | Zhao Z.K.,Dalian National Laboratory for Clean Energy
Chemical Engineering Journal | Year: 2013

Microwave-assisted direct conversion of cellulose into HMF in ionic liquids catalyzed by ZrCl4 has been investigated in search of an efficient and environment-friendly process. Firstly, some representative metal chlorides were used to catalyze the conversion of glucose into HMF, and it was demonstrated that ZrCl4 was superior to other catalysts. Then direct conversion of cellulose into HMF was catalyzed by ZrCl4 under microwave irradiation (MI). Under optimal conditions, a high HMF yield up to 51.4% was obtained from cellulose in 3.5min under MI at 400W. Controllable experiments indicated that both ionic liquids, MI and ZrCl4 showed synergetic effects on the efficient conversion of cellulose into HMF. This work provides a meaningful method for the conversion of carbohydrates into fine chemicals. © 2012 Elsevier B.V.


Wang J.,Kyushu University | Li H.-W.,Kyushu University | Chen P.,CAS Dalian Institute of Chemical Physics
MRS Bulletin | Year: 2013

The development of safe, efficient, and economic hydrogen storage technologies is key for implementation of a hydrogen-based energy economy. In the search for high-hydrogen content materials, attention in the past decade has shifted to amides and borohydrides, two representative solid-state chemical sorption materials with high hydrogen capacities that had not been previously explored for hydrogen storage. A large number of new amide and borohydride systems have recently been developed that expand the material scope for hydrogen storage. This article reviews the current progress in amides and borohydrides with emphases on material design and kinetic improvement. © 2013 Materials Research Society.


Li F.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Johansson B.,Dalian University of Technology | Johansson B.,KTH Royal Institute of Technology | Sun L.,CAS Dalian Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2010

We proposed a possible way of promoting the binding of H2 molecules on covalent organic frameworks crystals via substituting the bridge C2O2B rings with different metal-participated rings, which can naturally avoid the clustering of metal atoms. First-principles calculations on both crystalline phase and molecular fragments show that the H2 binding energy can be enhanced by a factor of four with regard to the undoped crystal, i.e. reaching about 10 kJ/mol. Grand canonical Monte Carlo simulations further confirm that such substitutional doping would improve the room temperature hydrogen storage capacity by a factor of two to three. © 2009 Professor T. Nejat Veziroglu.


Zhang F.,Beijing Jiaotong University | Xu X.,Beijing Jiaotong University | Tang W.,Nanjing University of Science and Technology | Zhang J.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2011

Recent years, the power conversion efficiency (PCE) of normal configuration organic solar cells (OSCs) has obtained rapid progress to reach more than 6% under standard illumination, which is reasonable value for the commercial criterion. More and more research attention has been paid on the stability and lifetime of OSCs. A novel structural OSCs with high work function metal or metal oxide as the top electrode and low work function metal as the bottom anode is proposed and named as inverted configuration OSCs. The inverted configuration OSCs with high work function metal as top cathode could improve OSCss lifetime, i.e., protecting cells from the damage by oxygen and moisture in air. Furthermore, the inverted configuration OSCs is the appealing alternative to the conventional regular structure due to the inherent vertical phase separation in the polymer active layers and high stability or long device lifetime. The inverted configuration OSCs have not only achieved an impressive PCE of 4.4%, but also exhibited an exceptional device lifetime without encapsulation. In this review article, the recent developments and vital researches on the inverted configuration OSCs are summarized. © 2011 Elsevier B.V. All rights reserved.


Yang S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Chu W.,CAS Dalian Institute of Chemical Physics | Song Z.,Dalian University of Technology | Zhao S.,Dalian University of Technology
Applied Catalysis B: Environmental | Year: 2011

Catalytic performance of platinum supported on H-ferrierite (H-FER) in selective catalytic reduction of NO and NO 2 by hydrogen (H 2-SCR) was investigated. 87.9% of the NO x was reduced with 56% of selectivity to N 2 when a gas mixture of 910ppm NO, 90ppm NO 2, 5000ppm H 2, 10% O 2 in N 2 passed through a 0.5wt.%Pt/H-FER catalyst at 110°C and gas hourly space velocity (GHSV) of 36,000h -1. It was found that the NO x reduction sharply decreased at higher reaction temperature, accompanied by large amount of NO 2 formation. The NO x conversion was also drastically decreased by increasing the concentration of NO 2 while holding the total concentration of NO+NO 2 in the feed gas mixture. Based on in situ Fourier transform infrared spectroscopy investigation, it was proposed that NO 2 and nitrate species were not essential intermediates of H 2-SCR over the catalyst, while NO δ+ species on Pt was a possible species for efficient elimination of NO. © 2011 Elsevier B.V.


Khan A.L.,Catholic University of Leuven | Li X.,CAS Dalian Institute of Chemical Physics | Vankelecom I.F.J.,Catholic University of Leuven
Journal of Membrane Science | Year: 2011

This paper describes the performance of sulfonated aromatic poly(ether ether ketone) (S-PEEK) membranes, directly prepared from the sulfonated monomer, for CO2 separation from gas mixtures containing N2 or CH4. Dense membranes with different degrees of sulfonation were prepared via solvent evaporation. Increasing degree of sulfonation simultaneously improves the permeability and selectivity of both gas pairs. The effect of counterions was investigated by converting S-PEEK membranes from the Na+-form in which they are prepared, to the H+ and multivalent cationic forms. Gas permeability and selectivity for polymers with divalent and trivalent counterions were higher than those for polymers in the monovalent and H+-forms. In order to study the stability and potential industrial application of these membranes, they were tested at different conditions of feed pressure, temperature and CO2 feed concentration. © 2011 Elsevier B.V.


Taketoshi A.,Tokyo Metroplitan University | Haruta M.,Tokyo Metroplitan University | Haruta M.,CAS Dalian Institute of Chemical Physics
Chemistry Letters | Year: 2014

Although gold in bulk is poorly active as a catalyst, it exhibits surprisingly high catalytic activity when deposited as nanoparticles (NPs) on base metal oxides. The catalytic performance of supported gold NPs can be created by choosing the kind of support materials, by controlling the size of gold, and by building up strong contact of gold with the supports. Since perimeter interfaces around gold NPs act, in principle, as the active sites for oxidation and hydrogenation, gold should be smaller than 10nm in diameter. A new area of research is clusters, which are smaller than 2 nm in diameter and less than 200 atoms. Gold clusters possess electronic structures different from those of bulk gold and at the same time provide increased fractions of edges and corners which are highly unsaturatedly coordinated sites. Accordingly, gold clusters will be blessed by unique catalytic performance, and many examples have recently been emerging. This article summarizes such examples in terms of "size- and structure-specificity," covering gas-phase free clusters, polymer- or organic-ligand-stabilized clusters in liquid phase, and clusters supported on base metal oxides, carbon materials, and organic polymers for gas-phase and liquid-phase reactions.


Haruta M.,Tokyo Metroplitan University | Haruta M.,CAS Dalian Institute of Chemical Physics
Angewandte Chemie - International Edition | Year: 2014

"Have you tried gold?" This question after a presentation on hydrogen oxidation steered Masatake Haruta's research on heterogeneous catalysis. He found that gold combined with 3d transition metal oxides could exhibit surprisingly high catalytic activity for carbon monoxide oxidation at temperatures as low as 203 K. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang W.,Nankai University | He X.-W.,Nankai University | Li W.-Y.,Nankai University | Zhang Y.-K.,Nankai University | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2012

A thermo-sensitive imprinted polymer coating CdTe quantum dots was developed to prepare fluorescent thermo-sensitive protein-affinity materials, which exhibited high specific recognition ability towards target proteins. © 2012 The Royal Society of Chemistry.


Fujitani T.,Japan National Institute of Advanced Industrial Science and Technology | Nakamura I.,Japan National Institute of Advanced Industrial Science and Technology | Haruta M.,Tokyo Metroplitan University | Haruta M.,CAS Dalian Institute of Chemical Physics
Catalysis Letters | Year: 2014

Gold nanoparticles supported on base metal oxides exhibit high catalytic activity in the low temperature oxidation of CO. Numerous studies have been carried out by using powder, single crystal, and planar model catalysts together with density functional theory calculations to elucidate the reaction mechanism and the nature of the active sites. A characteristic feature of these catalysts is that the moisture contained in the catalyst and in the reactant gas markedly enhances CO2 formation rates. The promoting role of moisture, which is advantageous for the practical applications to air purifiers, can be classified into four categories: (i) maintain cationic state of gold (Au 3+ or Au+), (ii) direct involvement of H2O and OH- groups in CO oxidation, (iii) activation of O2 molecules, and (iv) transformation of catalytic intermediates and inhibitors (spectators) such as carbonate species. The elucidation of the role of water in CO oxidation will deepen the understanding of the unique catalysis by gold. Graphical Abstract: [Figure not available: see fulltext.] © 2014 Springer Science+Business Media New York.


Xu S.,CAS Yantai Institute of Coastal Zone Research | Xu S.,University of Chinese Academy of Sciences | Chen L.,CAS Yantai Institute of Coastal Zone Research | Li J.,CAS Yantai Institute of Coastal Zone Research | And 2 more authors.
Journal of Hazardous Materials | Year: 2012

A novel functional monomer T-IPTS, 3-isocyanatopropyltriethoxysilane (IPTS) bearing thymine (T) bases, was synthesized for imprinting Hg 2+. Then a novel Hg 2+ ionic imprinted polymers (IIPs) based on thymine-Hg 2+-thymine (T-Hg 2+-T) interactions, i.e. Hg-IIPs-T, were prepared by sol-gel process for the first time in this work. The Hg-IIPs-T exhibited excellent selectivity towards Hg 2+ over Cd 2+, Zn 2+ Pb 2+, Co 2+, Mn 2+, Mg 2+ and Ca 2+, due to the specific T-Hg 2+-T interactions with high selectivity and high affinity. Accordingly, Hg-IIPs-T were used as solid-phase extraction (SPE) sorbents for preconcentration of trace Hg 2+ in water samples, and satisfactory recoveries ranging from 95.2 to 116.3% were obtained. Also, under optimized conditions, preconcentration factor and detection limit were achieved of 200 and 0.03μgL -1, respectively. The IIPs-T-SPE proved to be a rapid and high-effective cleanup and enrichment method for trace Hg 2+ in water samples. More importantly, these results indicated that devising and synthesizing new functional monomers tailor-made for template would become a general promising way to improve the selectivity and stability of IIPs. © 2012 Elsevier B.V.


Zhang Y.,CAS Dalian Institute of Chemical Physics | Tian Q.,Wuhan Institute of Technology
International Journal of Hydrogen Energy | Year: 2011

Stepwise reactions were observed in the ball milling and heating process of the LiBH4-NaNH2 system by means of X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR). During the ball milling process, two concurrent reactions take place in the mixture: 3LiBH 4 + 4NaNH2 → Li3Na(NH2) 4 + 3NaBH4 and LiBH4 + NaNH2 → LiNH2 + NaBH4. The heating process from 50 °C to 400 °C is mainly the concurrent reactions of Li3Na(NH 2)4 + 3LiBH4 → 2Li3BN 2 + NaBH4 + 8H2 and 2LiNH2 + LiBH4 → Li3BN2H8 → Li 3BN2 + 4H2, where the intermediate phases Li3Na(NH2)4 and LiNH2 serve as the reagents to decompose LiBH4. The merged equations for the mechanochemical and the heating reactions below 400 °C can be denoted as 3LiBH4 + 2NaNH2 → Li3BN2 + 2NaBH4 + 4H2. The maximum dehydrogenation capacity in closed system below 400 °C is 5.1 wt.% H2, which agrees well with the theoretical capacity (5.5 wt.% H2) of the merged equation and thus demonstrates the suggested pathway. The subsequent step consists of the decompositions of NaBH4 and Li3Na(NH2) 4 within the temperature range of 400 °C-600 °C. The apparent activation energies of the two steps are 114.8 and 123.5 kJ/mol, respectively. They are all lower than that of our previously obtained bulk LiBH4. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Zhang Y.,CAS Dalian Institute of Chemical Physics | Morin F.,University of Quebec | Huot J.,University of Quebec
International Journal of Hydrogen Energy | Year: 2011

In this work we investigated the effect of Ti, TiH2, TiB 2, TiCl3, and TiF3 additives on the hydrogen de/re-sorption kinetics and reaction pathways of LiH/MgB2 mixture. From high pressure differential scanning calorimeter (HP-DSC) measurements it was found that these additives all effectively decrease the onset temperature of hydrogenation. The isothermal hydrogenation/dehydrogenation measurements suggest that Ti, TiH2, and TiB2 can significantly improve the hydrogen sorption kinetics of LiH/MgB2 mixture. The absorption kinetics of TiF3 and TiCl3 doped samples are slower than the baseline (2LiH-MgB2 without additive), but their desorption kinetics are faster than the baseline and other additives doped systems. X-ray diffraction (XRD) analysis reveals that the additive Ti in LiH/MgB2 actively participates in both hydrogenation and dehydrogenation process, which can be regarded as an effective additive of this system. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Gao S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Chu W.,CAS Dalian Institute of Chemical Physics
Microporous and Mesoporous Materials | Year: 2012

Uniform SUZ-4 zeolite nanofiber (about 12 × 1500 nm) was obtained for the first time. The SUZ-4 zeolite was synthesized by hydrothermal treatment of the initial aluminosilicate gel at 150 °C with the assistance of definite amount of special seed slurry while without additional use of template. It was found that morphology of the SUZ-4 zeolite synthesized can be simply controlled by the character of seed slurry that is mainly determined by the crystallization period in preparation. The seed slurry containing plenty of less stable SUZ-4 crystallites obtained by crystallizing the aluminosilicate gel (7.9 KOH:1.0 Al 2O 3:2.6 TEAOH:21.2 SiO 2:498.6 H 2O) under rotation at 150 °C for 16 h leads to the synthesis of nanofibrous SUZ-4, while that primarily containing stable SUZ-4 crystallites obtained by prolonged crystallization period leads to the synthesis of rod-like zeolite. © 2012 Elsevier Inc. All rights reserved.


Su Y.,Dalian University of Technology | Su Y.,CAS Dalian Institute of Chemical Physics | Kang L.-H.,Shihezi University
International Journal of Quantum Chemistry | Year: 2012

A series of new heteroleptic iridium(III) complexes [Ir(C âN) 2(N âN)]PF 6 (1-6) (each with two cyclometalating C âN ligands and one neutral N âN ancillary ligand, where C âN = 2-phenylpyridine (ppy), 5-methyl-2-(4-fluoro)phenylpyridine (F-mppy), and N âN = 2,2'-dipyridyl (bpy), 1,10-phenanthroline (phen), 4,4'-diphenyl-2,2'-dipyridy (dphphen) were found to have rich photophysical properties. Theoretical calculations are employed for studying the photophysical and electrochemical properties. All complexes are investigated using density functional theory. Excited singlet and triplet states are examined using time-dependent density functional theory. The low-lying excited-state geometries are optimized at the ab initio configuration interaction singles level. Then, the excited-state properties are investigated in detail, including absorption and emission properties, photoactivation processes. The excited state of complexes is complicated and contains triplet metal-to-ligand charge transfer, triplet ligand-to-ligand charge transfer simultaneously. Importantly, the absorption spectra and emission maxima can be tuned significantly by changing the NN ligands and CN ligands. © 2011 Wiley Periodicals, Inc.


Zhang G.,Dalian University of Technology | Wang S.,Dalian University of Technology | Zhao S.,Dalian University of Technology | Fu L.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2011

Heterogeneous electrocatalytic wet H2O2 oxidation technique for the removal of azo dye amaranth from aqueous solution was studied in the presence of solid CuO/γ-Al2O3 catalyst and anthraquinonemonosulphonate/polypyrrole (AQS/PPy) composite cathode able to electrogenerate H2O2 in situ. The spherical CuO/γ-Al2O3 catalysts with various CuO loadings and calcined at different temperatures were characterized by BET, ESEM-EDS, XRD and XPS. Several parameters affecting H2O2 electrogeneration and dye degradation such as solution pH, cathode potential (Eca), oxygen flow rate (VO2), CuO loading, reaction temperature as well as catalyst calcination temperature were investigated. Experimental results revealed that the optimal condition for H2O2 electrogeneration on the AQS/PPy composite modified cathode is VO2=0.4 ml min-1, Eca=-0.4V and pH 4.3. On this occasion, ca. 90% chroma decay and 60% TOC removal of dye were achieved with 450°C-calcined 5.78wt%-CuO/γ-Al2O3 catalyst and 70°C reaction temperature. Dye degradation follows the second-order kinetics. Leaching tests showed that the leaching copper amount during the oxidation is only 4.0-7.0% per run and the role of heterogeneous activity is dominant. The catalytic activity of CuO/γ-Al2O3 catalyst could be recovered after multiple runs by a re-calcination step. Furthermore, the stability of the AQS/PPy composite after consecutive operation was also investigated by chronoamperometric and EIS techniques. © 2011 Elsevier B.V.


Feng L.,Liaoning University of Technology | Feng L.,CAS Dalian Institute of Chemical Physics
IEEE Journal of Quantum Electronics | Year: 2015

Attosecond pulse generation from high-order harmonic spectrum has been theoretically investigated using the two-color orthogonal field combined with a linear infrared pulse. It shows that by properly adding a linear infrared pulse to the orthogonal field in x - or y -direction, not only the harmonic cutoffs and the harmonic yields are enhanced, but also the modulations on the harmonic spectra are decreased, resulting in two intense supercontinua with the bandwidths of 240 and 130 eV, respectively. Finally, the proper superposition of harmonics, two isolated pulses with durations of 43 and 50 as can be obtained, which are 1.5 and 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case. © 1965-2012 IEEE.


Wang Y.-Q.,Nankai University | Liu Y.,Nankai University | He X.-W.,Nankai University | Li W.-Y.,Nankai University | And 2 more authors.
Talanta | Year: 2012

Chemically denatured ovalbumin (dOB) was used to modify the surface of 3-mercaptopropionic acid (MPA) stabilized CdTe quantum dots (QDs), which resulted in a great enhancement of the synchronous fluorescence intensity. Moreover, dOB shell layer can effectively prevent the binding of other cations onto the QDs core and enhance the selective binding ability of Hg2 to dOB coated CdTe QDs (CdTe-dOB QDs). A simple method with high sensitivity and selectivity was developed for the determination of Hg2 with the CdTe-dOB QDs as fluorescence probe based on the merits of synchronous fluorescence spectroscopy (SFS). When scanning with excitation and emission wavelengths of 250 nm and 470 nm (Δλ=λem- λex=220 nm), respectively, the maximum synchronous fluorescence peak of the CdTe-dOB QDs was located at 328 nm. Under optimal conditions, the change of the synchronous fluorescence intensity was in good linear relationship with the Hg2 concentration in the range of 0.08×10-7 to 30.0×10-7 mol L-1 and the detection limit was 4.2×10-9 mol L-1 (S/N=3). The relative standard deviation of seven replicate measurements for the concentration of 2.0×10-7 mol L-1 and 20.0×10-7 mol L-1 were 2.8% and 2.3%, respectively. Compared with general fluorescence methods, the proposed method, which combined the advantages of high sensitivity of synchronous fluorescence and specific response of Hg2 to CdTe-dOB, had a wider linear range and higher sensitivity. Furthermore, the proposed method was applied to the determination of trace Hg2 in water samples with satisfactory results. © 2012 Elsevier B.V.


Zhang M.,Nankai University | Zhang X.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Nanoscale | Year: 2012

In this study, we report a facile method for the preparation of core-shell magnetic molecularly imprinted polymers (MIPs) for protein recognition. Uniform carboxyl group functionalized Fe 3O 4 nanoparticles (NPs) were synthesized using a solvothermal method. Magnetic MIPs were synthesized by self-polymerization of dopamine in the presence of template protein on the surface of the Fe 3O 4 NPs. A thin layer of polydopamine can be coated on Fe 3O 4 NPs via dopamine self-polymerization and the imprinted polydopamine shells can be controlled by the mass ratio of Fe 3O 4 NPs and dopamine. More importantly, there is a critical value of polydopamine shell thickness for the maximum rebinding capacity. The as-prepared lysozyme-imprinted Fe 3O 4@polydopamine NPs show high binding capacity and acceptable specific recognition behavior towards template proteins. This method provides the possibility for the separation and enrichment of abundant proteins in proteomic analysis. © 2012 The Royal Society of Chemistry.


Zhu Y.,CAS Shenyang Institute of Metal Research | Zhu Y.,Anshan Normal University | Zhang B.,CAS Shenyang Institute of Metal Research | Liu X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2015

Non-precious Fe/N co-modified carbon electrocatalysts have attracted great attention due to their high activity and stability in oxygen reduction reaction (ORR). Compared to iron-free N-doped carbon electrocatalysts, Fe/N-modified electrocatalysts show four-electron selectivity with better activity in acid electrolytes. This is believed relevant to the unique Fe-N complexes, however, the Fe-N structure remains unknown. We used o,m,p-phenylenediamine as nitrogen precursors to tailor the Fe-N structures in heterogeneous electrocatalysts which contain FeS and Fe3C phases. The electrocatalysts have been operated for 5000 cycles with a small 39 mV shift in half-wave potential. By combining advanced electron microscopy and Mössbauer spectroscopy, we have identified the electrocatalytically active Fe-N6 complexes (FeN6, [FeIII(porphyrin)(pyridine)2]). We expect the understanding of the FeN6 structure will pave the way towards new advanced Fe-N based electrocatalysts. The active FeNx sites in Fe/N/C catalysts were identified by electron microscopy and Mössbauer spectroscopy as the six-coordinate FeIII species [FeIII(porphyrin)(pyridine)2]. The results lead the way to target-specific synthesis of highly active and stable non-precious metal catalysts for oxygen reduction reaction. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ji M.,Dalian University of Technology | Zhang X.,Dalian University of Technology | Wang J.,CAS Dalian Institute of Chemical Physics | Park S.-E.,Inha University
Journal of Molecular Catalysis A: Chemical | Year: 2013

Fe-doped MgAl2O4 spinel catalyst of MgFe 0.1Al1.9O4 and supported catalyst of Fe 2O3-MgO/γ-Al2O3 for ethylbenzene dehydrogenation in the presence of CO2 were studied by Mössbauer spectroscopy (MS) combining with the partial reduction method in the presence of H2, and the catalytic activity of the ferrous iron species was discussed. The results showed that the catalytic performance of Fe3+ existing in spinel is superior to α-Fe2O 3, and the synergistic effect between Fe2+ and Fe 3+ might indeed increase the catalytic activity since Fe 2+-O2- formed in the process of reduction has moderate basicity, which was more favorable for desorption of CO2 compared with Mg2+-O2-. The reduced MgFe0.1Al 1.9O4 containing Fe2+ of around 25% exhibits much higher catalytic activity than unreduced catalyst, with improved styrene yield nearly 2 times to 45.0%. MgxFe1-xO as another ferrous iron species formed in the reduction process of Fe2O 3-MgO/γ-Al2O3 showed inconspicuously catalytic activity. © 2013 Elsevier Ltd. All rights reserved.


Zhang F.,University of Tokyo | Zhang F.,CAS Dalian Institute of Chemical Physics | Yamakata A.,Toyota Technological Institute | Yamakata A.,Japan Science and Technology Agency | And 8 more authors.
Journal of the American Chemical Society | Year: 2012

Highly efficient water oxidation utilizing visible photons of up to 600 nm is a crucial step in artifical photosynthesis. Here we present a highly active photocatalyst for visible-light-driven water oxidation, consisting of single-crystalline meso- and macroporous LaTiO 2N (LTON) with a band gap of 2.1 eV, and earth-abundasnt cobalt oxide (CoO x) as a cocatalyst. The optimized CoO x/LTON had a high quantum efficiency of 27.1 ± 2.6% at 440 nm, which substantially exceeds the values reported for previous particulate photocatalysts with a 600-nm absorption edge. © 2012 American Chemical Society.


Xu Z.,CAS Dalian Institute of Chemical Physics | Liu X.,University of Cambridge | Pan J.,University of Cambridge | Spring D.R.,University of Cambridge
Chemical Communications | Year: 2012

We report a coumarin-derived fluorescent sensor for Zn 2+ termed CTS. CTS shows excellent binding selectivity for Zn 2+ over competing metal ions due to the transformable ability of CTS, that is the displacement of other metal ions by Zn 2+, which induces transformation of chelation from an amide to an imidic acid tautomeric form. © 2012 The Royal Society of Chemistry.


Chen S.,Chongqing University of Technology | Wei Z.,Chongqing University of Technology | Qi X.,Chongqing University of Technology | Dong L.,Chongqing University of Technology | And 4 more authors.
Journal of the American Chemical Society | Year: 2012

We have designed and synthesized a polyaniline (PANI)-decorated Pt/C@PANI core-shell catalyst that shows enhanced catalyst activity and durability compared with nondecorated Pt/C. The experimental results demonstrate that the activity for the oxygen reduction reaction strongly depends on the thickness of the PANI shell and that the greatest enhancement in catalytic properties occurs at a thickness of 5 nm, followed by 2.5, 0, and 14 nm. Pt/C@PANI also demonstrates significantly improved stability compared with that of the unmodified Pt/C catalyst. The high activity and stability of the Pt/C@PANI catalyst is ascribed to its novel PANI-decorated core-shell structure, which induces both electron delocalization between the Pt d orbitals and the PANI π-conjugated ligand and electron transfer from Pt to PANI. The stable PANI shell also protects the carbon support from direct exposure to the corrosive environment. © 2012 American Chemical Society.


Ren Y.,Henan University of Science and Technology | Yan M.,Henan University of Science and Technology | Wang J.,Henan University of Science and Technology | Wang J.,Henan Normal University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Breaking point: An effective reductive cleavage of inert aryl C-O bonds with an inexpensive iron catalyst has been developed. During this process, the reduction of the arene rings was not observed. This catalytic system also enabled the selective cleavage of the β-O-4 linkage of lignin model compounds under an atmosphere of hydrogen, thus offering an opportunity for the depolymerization of lignin. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chen R.,CAS Dalian Institute of Chemical Physics
Molecular & cellular proteomics : MCP | Year: 2011

A robust, reproducible, and high throughput method was developed for the relative quantitative analysis of glycoprotein abundances in human serum. Instead of quantifying glycoproteins by glycopeptides in conventional quantitative glycoproteomics, glycoproteins were quantified by nonglycosylated peptides derived from the glycoprotein digest, which consists of the capture of glycoproteins in serum samples and the release of nonglycopeptides by trypsin digestion of captured glycoproteins followed by two-dimensional liquid chromatography-tandem MS analysis of released peptides. Protein quantification was achieved by comparing the spectrum counts of identified nonglycosylated peptides of glycoproteins between different samples. This method was demonstrated to have almost the same specificity and sensitivity in glycoproteins quantification as capture at glycopeptides level. The differential abundance of proteins present at as low as nanogram per milliliter levels was quantified with high confidence. The established method was applied to the analysis of human serum samples from healthy people and patients with hepatocellular carcinoma (HCC) to screen differential glycoproteins in HCC. Thirty eight glycoproteins were found with substantial concentration changes between normal and HCC serum samples, including α-fetoprotein, the only clinically used marker for HCC diagnosis. The abundance changes of three glycoproteins, i.e. galectin-3 binding protein, insulin-like growth factor binding protein 3, and thrombospondin 1, which were associated with the development of HCC, were further confirmed by enzyme-linked immunosorbent assay. In conclusion, the developed method was an effective approach to quantitatively analyze glycoproteins in human serum and could be further applied in the biomarker discovery for HCC and other cancers.


Vijayakumar M.,Pacific Northwest National Laboratory | Li L.,Pacific Northwest National Laboratory | Graff G.,Pacific Northwest National Laboratory | Liu J.,Pacific Northwest National Laboratory | And 3 more authors.
Journal of Power Sources | Year: 2011

The V5+ electrolyte solution from Vanadium Redox Flow Batteries was studied by variable temperature 17O and 51V Nuclear Magnetic Resonance (NMR) spectroscopy and density functional theory (DFT) based computational modeling. It was found that the V5+ species exist as hydrated penta co-ordinated vanadate ion, i.e. [VO2(H 2O)3]1+. This hydrated structure is not stable at elevated temperature and change into neutral H3VO4 molecule via a deprotonation process and subsequently leading to the observed V2O5 precipitation in V5+ electrolyte solutions. © 2010 Elsevier B.V. All rights reserved.


Liu X.,University of Cambridge | Xu Z.,CAS Dalian Institute of Chemical Physics | Cole J.M.,University of Cambridge | Cole J.M.,University of New Brunswick
Journal of Physical Chemistry C | Year: 2013

Understanding the molecular origins of the optoelectronic properties of fluorophores provides rational guidelines for chemists to synthesize better-performing dyes. Factors affecting the UV-vis absorption spectral shift, molar extinction coefficients, and Stokes shift of fluorophores are herein examined at the molecular level, via both (time-dependent) density functional theory-based calculations and the empirical harmonic-oscillator-stabilization- energy (HOSE) and bond-length-alternation (BLA) models. The importance of these factors is discussed using six coumarin dyes as exemplars. In particular, a special focus is devoted to the Stokes shift, a critical parameter in fluorophores. It is demonstrated that incorporating a "rotational" substituent in a fluorophore molecule with tailored steric hindrance effects and resonance effects leads to a substantial increase in the Stokes shift, not only in coumarins but also in other chemical dye families: boron-dipyrromethenes (BODIPYs), cyanines, and stilbenes. Structure-property relationships concerning the rotational substituent are discussed in detail with examples of several dye families. These findings lead to the proposal of molecular design criteria that enable one to tune the Stokes shift. Such criteria provide a foundation for the molecular engineering of fluorophores with improved optoelectronic properties. © 2013 American Chemical Society.


Deng Q.,Tianjin University of Science and Technology | Li Y.,Tianjin University of Science and Technology | Wu J.,Tianjin University of Science and Technology | Liu Y.,Tianjin University of Science and Technology | And 3 more authors.
Chemical Communications | Year: 2012

Fluorescent conjugated polymer, poly(3-aminobenzoic acid), as a new class of fluorescence sensor for detection of trace amounts of water in organic solvents was developed. This sensor exhibits extraordinarily high sensitivity with a detection limit as low as 0.008 wt% for water in DMF. © 2012 The Royal Society of Chemistry.


Wicker B.F.,Indiana University Bloomington | Fan H.,Indiana University Bloomington | Fan H.,CAS Dalian Institute of Chemical Physics | Hickey A.K.,Indiana University Bloomington | And 5 more authors.
Journal of the American Chemical Society | Year: 2012

The anilide-methyl complex (PNP)Sc(NH[DIPP])(CH3) (1) [PNP - = bis(2-diisopropylphosphino-4-tolyl)amide, DIPP = 2,6-diisopropylphenyl] eliminates methane (kavg = 5.13 × 10-4 M-1s-1 at 50 °C) in the presence of pyridine to generate the transient scandium imido (PNP)Sc=[DIPP](NC 5H5) (A-py), which rapidly activates the C-H bond of pyridine in 1,2-addition fashion to form the stable pyridyl complex (PNP)Sc(NH[DIPP])(η2-NC5H4) (2). Mechanistic studies suggest the C-H activation process to be second order overall: first order in scandium and first order in substrate (pyridine). Pyridine binding precedes elimination of methane, and α-hydrogen abstraction is overall-rate-determining [the kinetic isotope effect (KIE) for 1-d1 conversion to 2 was 5.37(6) at 35 C and 4.9(14) at 50 C] with activation parameters ΔH‡ = 17.9(9) kcal/mol and ΔS‡ = -18(3) cal/(mol K), consistent with an associative-type mechanism. No KIE or exchange with the anilide proton was observed when 1-d3 was treated with pyridine or thermolyzed at 35 or 50 °C. The post-rate-determining step, C-H bond activation of pyridine, revealed a primary KIE of 1.1(2) at 35 °C for the intermolecular C-H activation reaction in pyridine versus pyridine-d5. Complex 2 equilibrated back to the imide A-py slowly, as the isotopomer (PNP)Sc(ND[DIPP])(η2-NC5H4) (2-d 1) converted to (PNP)Sc(NH[DIPP])(η2-NC 5H3D) over 9 days at 60 °C. Molecular orbital analysis of A-py suggested that this species possesses a fairly linear scandium imido motif (169.7 ) with a very short Sc-N distance of 1.84 Å. Substituted pyridines can also be activated, with the rates of C-H activation depending on both the steric and electronic properties of the substrate. © 2012 American Chemical Society.


Zhang Q.,Dalian Medical University | Liu T.,Dalian Medical University | Qin J.,CAS Dalian Institute of Chemical Physics
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2012

Circulating tumor aggregates exhibit a high metastatic potential and could potentially serve as an important target for cancer therapies. In this study, we developed a microfluidic model that reconstitutes and is representative of the principal components of biological blood vessels, including vessel cavity, endothelium, and perivascular matrix containing chemokines. Using this model, the transendothelial invasion of tumor aggregates can be observed and recorded in realtime. In this study we analyzed the extravasation process of salivary gland adenoid cystic carcinoma (ACC) cell aggregates. ACC aggregates transmigrated across the endothelium under the stimulation of chemokine CXCL12. The endothelial integrity was irreversibly damaged at the site of transendothelial invasion. The transendothelial invasion of ACC aggregates was inhibited by AMD3100, but the adhesion of ACC aggregates to the endothelium was not affected by the CXCR4 antagonist. This model allows for detailed study of the attachment and transendothelial invasion of tumor aggregates; thus, it would be a useful tool for analysis of the underlying mechanisms of metastasis and for testing novel anti-metastasis agents. This journal is © The Royal Society of Chemistry 2012.


Wang F.,Nankai University | Guan Y.,CAS Dalian Institute of Chemical Physics | Zhang S.,Nankai University | Xia Y.,Nankai University
Journal of Chromatography A | Year: 2012

A new nano-scale restricted-access matrix (RAM) SiO 2 (MCM-41) with relatively high Ti-content (Ti/Si=0.1), but superior surface area (1129m 2/g), was successfully synthesised for the enrichment of phosphopeptides. The TiO 2 was incorporated into the Si-MCM-41 via a hydrothermal process and the external surface was modified with alkyl diol by the successive hydrolysis of γ-(glycidyloxypropyl) trimethoxysilane (GPTMS). Scanning electron microscopy, transmission electron microscopy, N 2 adsorption and Fourier transform infrared spectroscopy were used to characterise the alkyl diol-Ti-MCM-41. The appropriate pore diameter (2nm) coupled to the marshy weeds-like hydrophilic external surface result in an efficient size-exclusion effect for the adsorption of standard cytochrome c with a molecular weight (MW) of ca. 12.4kDa. At the same time, the strong affinity interaction between the incorporated titanium in the framework and the phosphoryl groups of phosphopeptides demonstrated a selective extract of phosphopeptides from the tryptic digestion. The detection sensitivity for phosphopeptides, determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) was as low as 5fmol for standard tryptic digest of β-casein. Therefore, this alkyl diol-Ti-MCM-41 mesoporous material can be used as a potential adsorbent for applications in MS-based phosphoproteomics. © 2012 Elsevier B.V.


Zhang L.,Shanxi Normal University | Yang W.,CAS Dalian Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2012

We have fabricated BaCe 0.8Gd 0.2O 3-δ (BCGO) thin films with thickness in the range of 5-10 μm over substrates composed of Ce 0.8Gd 0.2O 1.9 (CGO)-NiO using a colloidal spray deposition method. A perovskite-type BaZr 0.2Co 0.4Fe 0.4O 3-δ (BZCFO) was employed as a novel cathode material. The performances of solid oxide fuel cells were investigated from 450°C to 600°C. The fuel cell with the BCGO film of 9 μm in thickness showed maximum power outputs of 237, 192, 136 and 89 mW cm -2 at 600, 550, 500 and 450°C, respectively. The impedance measurements at open circuit conditions showed the polarization resistances of the electrode were about 0.25 and 1.00 Ω cm 2 at 600 and 500°C, respectively. The low interfacial resistances indicated that the BZCFO was a promising cathode material for low-temperature proton-conducing solid oxide fuel cells. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Liu L.,Dalian University of Technology | Liu L.,CAS Dalian Institute of Chemical Physics | Hao J.,Dalian University of Technology | Shi Y.,Dalian University of Technology | And 2 more authors.
RSC Advances | Year: 2015

With the aids of density functional theory (DFT) and time-dependent density functional theory (TD-DFT), the explosives-detection mechanism of a typical luminescent metal-organic framework (MOF) sensor has been comprehensively studied by investigating the interactions between the framework and two analytes, namelty, benzene and nitrobenzene. By studying both the periodic crystal models and cluster models we obtained an in-depth understanding of the detecting mechanism from the viewpoint of electronic coupling between the analyte and sensor. Intermolecular electron transfer from the conduction bands of the framework to the LUMO of nitrobenzene is demonstrated to induce the luminescence quenching phenomenon observed in previous experiments. π-π stacking and hydrogen bonding interactions are found to play essential roles in this intermolecular electron transfer process. π-π stacking provides large fragment orbital overlaps between the unoccupied orbitals of the analyte and sensor, which serves as a highly efficient electron transfer bridge. Hydrogen bonds alone cannot provide enough overlaps for electron transfer but are found to reinforce the π-π stacking interactions. The cooperation of the two interactions induces facile intermolecular electron transfer which strongly quenches the luminescence of the MOF sensor. This work sheds light on the analyte-sensor interactions inside the MOF sensors and would provide valuable insights into the design of high efficient explosivesdetecting MOF sensors. © The Royal Society of Chemistry 2015.


Yang D.,Dalian University of Technology | Yang D.,CAS Dalian Institute of Chemical Physics | Cong S.-L.,Dalian University of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

The dissociation dynamics of HD+ molecules is studied theoretically by numerically solving the time-dependent Schrödinger equation in which the molecular vibrational and rotational degrees of freedom are included. Based on the Born-Oppenheimer approximation, the ground 1sσg state and the excited 2pσu state are taken into account, corresponding to two dissociative channels HD +→D + H+ and HD+→H + D+, respectively. Two dissociative nuclear wave packets overlap and interfere after excited by two ultrashort laser pulses. The interference patterns can be controlled by varying the laser parameters and the dissociation probabilities are demonstrated for different laser fields. The kinetic energy-dependent distributions of the fragments are calculated using an asymptotic-flow expression in the momentum space. The branching ratio D+/(H + + D+), as a function of the delay time and the relative phase between two laser pulses, is also discussed. © 2011 American Physical Society.


Sun J.,Washington State University | Karim A.M.,Pacific Northwest National Laboratory | Mei D.,Pacific Northwest National Laboratory | Engelhard M.,Pacific Northwest National Laboratory | And 3 more authors.
Applied Catalysis B: Environmental | Year: 2015

The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted into acetaldehyde and then into acetone, followed by acetone steam reforming. More than 90% of carbon was found to follow this reaction pathway. N2 sorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), in situ X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, as well as theoretical density functional theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ethanol steam reforming (ESR). It was found that metallic cobalt is mainly responsible for the acetone steam-reforming reactions, while CoO and basic sites on the support play a key role in converting ethanol into acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam-reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam-reforming catalysts. © 2014 Elsevier B.V.


Zhang W.,Nankai University | He X.-W.,Nankai University | Chen Y.,Nankai University | Li W.-Y.,Nankai University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2011

A newly designed molecularly imprinted polymer (MIP) material was fabricated and successfully utilized as recognition element to develop a quantum dots (QDs) based MIP-coated composite for selective recognition of the template cytochrome c (Cyt). The composites were synthesized by sol-gel reaction (imprinting process). The imprinting process resulted in an increased affinity of the composites toward the corresponding template. The fluorescence of MIP-coated QDs was stronger quenched by the template versus that of non-imprinted polymer (NIP)-coated QDs, which indicated the composites could recognize the corresponding template. The results of specific experiments further exhibited the recognition ability of the composites. Under optimum conditions, the linear range for Cyt is from 0.97μM to 24μM, and the detection limit is 0.41μM. The new composites integrated the high selectivity of molecular imprinting technology and fluorescence property of QDs and could convert the specific interactions between imprinted cavities and corresponding template to the obvious changes of fluorescence signal. Therefore, a simple and selective sensing system for protein recognition has been realized. © 2010 Elsevier B.V.


Li B.,CAS Yantai Institute of Coastal Zone Research | Zhang W.,CAS Yantai Institute of Coastal Zone Research | Zhang W.,University of Chinese Academy of Sciences | Chen L.,CAS Yantai Institute of Coastal Zone Research | Lin B.,CAS Dalian Institute of Chemical Physics
Electrophoresis | Year: 2013

In this study, a fast, low-cost, and facile spray method was proposed. This method deposits highly sensitive surface-enhanced Raman scattering (SERS) silver nanoparticles (AgNPs) on the paper-microfluidic scheme. The procedures for substrate preparation were studied including different strategies to synthesize AgNPs and the optimization of spray cycles. In addition, the morphologies of the different kinds of paper substrates were characterized by SEM and investigated by their SERS signals. The established method was found to be favorable for obtaining good sensitivity and reproducible results. The RSDs of Raman intensity of randomly analyzing 20 spots on the same paper or different filter papers depositing AgNPs are both below 15%. The SERS enhancement factor is approximately 2 × 107. The whole fabrication is very rapid, robust, and does not require specific instruments. Furthermore, the total cost for 1000 pieces of chip is less than $20. These advantages demonstrated the potential for growing SERS applications in the area of environmental monitoring, food safety, and bioanalysis in the future. © 2013 WILEY-VCH Verlag GmbH & Co.


Wang N.,University of Sichuan | Chu W.,University of Sichuan | Zhang T.,CAS Dalian Institute of Chemical Physics | Zhao X.S.,National University of Singapore
International Journal of Hydrogen Energy | Year: 2012

A series of Ce-incorporated SBA-15 mesoporous materials were synthesized through direct hydrothermal synthesis method and further impregnated with 12 wt.% Ni. The samples were characterized by ICP-AES, XRD, N 2 physisorption, XPS, TPR, H 2 chemisorption, TGA, temperature- programmed hydrogenation (TPH) and TEM measurements. The low-angle XRD and N 2 physisorption results showed the Ce successfully incorporated into the framework of SBA-15. The catalytic properties of these catalysts were investigated in methane reforming with CO 2. The Ce/Si molar ratio had a significant influence on the catalytic performance. The highest catalytic activity and long-term stability were obtained over the Ni/Ce-SBA-15 (Ce/Si = 0.04) sample. The improved catalytic behavior could be attributed to the cerium impact in the framework of SBA-15, where cerium promoted the dispersion of nano-sized Ni species and inhibited the carbon formation. In comparison with the effect of CeO 2 crystallites in SBA-15, cerium in the framework of SBA-15 promoted the formation of the nickel metallic particles with smaller size. The XRD and TGA results exhibited that carbon deposition was responsible for activity loss of Ni/SBA-15 and Ni/Ce-SBA-15 (Ce/Si = 0.06) catalysts. TEM results showed that the hexagonal mesopores of SBA-15 were still kept intact after reaction and the pore walls of SBA-15 prevented the aggregation of nickel. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Kong X.,Nankai University | Gao R.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Journal of Chromatography A | Year: 2012

In this study, we present a general method to prepare the core-shell magnetic molecularly imprinted polymers (MIPs) nanoparticles (NPs) for sulfamethazine (SMZ). The resulting Fe 3O 4@MIPs NPs possess a highly improved imprinting effect, fast adsorption kinetics and high adsorption capacity, and can be applied to extract sulfonamide in the poultry feed. In this protocol, the magnetite NPs were synthesized by co-precipitating Fe 2+ and Fe 3+ in an ammonia solution first. Silica was then coated on the Fe 3O 4 NPs using a sol-gel method to obtain silica shell magnetic NPs. Subsequently, the vinyl groups were grated onto silica-modified Fe 3O 4 surface by 3-methacryloyloxypropyltrimethoxysilane. Finally, the MIPs films were formed on the surface of Fe 3O 4@SiO 2 by the copolymerization of vinyl end groups with functional monomer, methacrylic acid, cross-linking agent, ethylene glycol dimethacrylate, the initiator azo-bis-isobutyronitrile and template molecule, sulfamethazine. The morphology, magnetic, adsorption and recognition properties of Fe 3O 4@MIPs NPs were characterized using transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrometer, vibrating sample magnetometer (VSM) and re-binding experiments. The results showed that the binding sites of Fe 3O 4@MIPs were good accessibility, fast adsorption rate and the maximum adsorption capacity of Fe 3O 4@MIPs to SMZ was 344.8μgg -1. The selectivity of the obtained Fe 3O 4@MIPs NPs were elucidated by the different rebinding capability of SMZ and structural related sulfonamides in the mixed solution. The results indicated that the Fe 3O 4@MIPs had high imprinting factor 9.5 and significant selectivity. A method was developed for enrichment and determination of SMZ in the poultry feed samples with recoveries of duck and chicken feed ranging from 63.3 to 76.5% and 68.7 to 74.7%, respectively and the relative standard deviations (RSD) (<6.7%). © 2012 Elsevier B.V..


Cao D.-S.,Central South University | Huang J.-H.,Central South University | Liang Y.-Z.,Central South University | Xu Q.-S.,Central South University | Zhang L.-X.,CAS Dalian Institute of Chemical Physics
TrAC - Trends in Analytical Chemistry | Year: 2012

Large amounts of data from high-throughput analytical instruments have generally become more and more complex, bringing a number of challenges to statistical modeling. To understand complex data further, new statistically-efficient approaches are urgently needed to: (1)select salient features from the data;(2)discard uninformative data;(3)detect outlying samples in data;(4)visualize existing patterns of the data;(5)improve the prediction accuracy of the data; and, finally,(6)feed back to the analyst understandable summaries of information from the data.We review current developments in tree-based ensemble methods to mine effectively the knowledge hidden in chemical and biology data. We report on applications of these algorithms to variable selection, outlier detection, supervised pattern analysis, cluster analysis, and tree-based kernel and ensemble learning.Through this report, we wish to inspire chemists to take greater interest in decision trees and to obtain greater benefits from using the tree-based ensemble techniques. © 2012 Elsevier Ltd.


Wu H.Y.,Nanyang Technological University | Fan X.F.,Nanyang Technological University | Kuo J.-L.,Nanyang Technological University | Kuo J.-L.,Academia Sinica, Taiwan | Deng W.-Q.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2010

By the incorporation of C atoms into (BN)12 fullerene, our theoretical investigation shows that carbon doped boron nitride cages (BNC) can achieve a high hydrogen storage amount of 7.43 wt%, and dehydrogenation of the corresponding BNC hydrides (BNCH) is thermodynamically favored for practical applications of hydrogen energy, making BNC competitive candidates for hydrogen storage materials. © The Royal Society of Chemistry 2010.


Gai Q.-Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Zhang T.,Beijing Institute of Technology | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Journal of Chromatography A | Year: 2011

Currently, small proteins imprinting are more reported since large proteins molecular imprinting faces challenge due to their bulk size and complex structure. In this work, bovine serum albumin (BSA) surface-imprinted magnetic polymer was successfully synthesized based on atomic transfer radical polymerization (ATRP) method in the presence of common monomer (N-isopropylacrylamide) with the assistant of basic functional monomer (N-[3-(dimethylamino)propyl]-methacrylamide), which provides a achievable attempt for imprinting larger target proteins based on the ATPR with the mild reaction conditions. The BSA-imprinted polymer exhibited higher adsorption capacity and selectivity to BSA over the non-imprinted polymer. Competitive adsorption tests indicated the BSA-imprinted polymer had better selective adsorption and recognition properties to BSA in the mixture. The obtained BSA-imprinted polymer was applied to bovine serum, which also showed selectivity to BSA. In addition, a conventional aqueous two-phase solution of PEG/sulphate was used as elution for adsorbed BSA, which was compared with common NaCl elution. © 2011 Elsevier B.V.


Huang C.,Northwest University, China | Zheng C.,Northwest University, China | Li Y.,Dalian University of Technology | Wang Y.,Northwest University, China | And 2 more authors.
Briefings in Bioinformatics | Year: 2013

Systems pharmacology is an emerging field that integrates systems biology and pharmacology to advance the process of drug discovery, development and the understanding of therapeutic mechanisms. The aim of the present work is to highlight the role that the systems pharmacology plays across the traditional herbal medicines discipline, which is exemplified by a case study of botanical drugs applied in the treatment of depression. First, based on critically examined pharmacology and clinical knowledge, we propose a large-scale statistical analysis to evaluate the efficiency of herbs used in traditional medicines. Second, we focus on the exploration of the active ingredients and targets by carrying out complex structure-, omics- and network-based systematic investigations. Third, specific informatics methods are developed to infer drug- disease connections, with purpose to understand how drugs work on the specific targets and pathways. Finally, we propose a new systems pharmacology method, which is further applied to an integrated platform (Herbal medicine Systems Pharmacology) of blended herbal medicine and omics data sets, allowing for the systematization of current and traditional knowledge of herbal medicines and, importantly, for the application of this emerging body of knowledge to the development of new drugs for complex human diseases. © The Author 2013.


Yang X.,Beihang University | Guo F.,Beihang University | Xue S.,CAS Dalian Institute of Chemical Physics | Wang X.,Beihang University
Renewable and Sustainable Energy Reviews | Year: 2016

Algae are considered to be the most viable feedstock for alternative aviation fuel production. The alternative (nonpetroleum) fuel from biomass could be produced as "drop-in" fuels with no effects on flight safety and would be interchangeable with current fuels in performance and handling. Accordingly, alternative fuels blended with petroleum fuels should meet jet fuel's. © 2015 Elsevier Ltd. All rights reserved.


Chen D.,Liaoning Normal University | Li X.,CAS Dalian Institute of Chemical Physics
Journal of Power Sources | Year: 2014

Sulfonated poly(ether ether ketone) (C-SPEEK) membranes with pendent carboxylic acid groups are prepared and first investigated for vanadium flow battery (VFB) application. The introduction of carboxylic acid groups can effectively improve the ion conductivities of C-SPEEK membranes, while, keep their ion selectivities. The prepared C-SPEEK membranes exhibit excellent performance under VFB operating condition. VFB single cell assembled with C-SPEEK-50 membranes shows much higher energy efficiency (85% Vs 82%) and columbic efficiency (97.3% Vs 94.6%) than that assembled with Nafion 115. The membrane keeps a stable performance after more than 180 cycles charge-discharge test, showing good stability. © 2013 Elsevier B.V. All rights reserved.


Jian G.,Nankai University | Liu Y.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Nanoscale | Year: 2012

In this study, we report a novel method to synthesize core-shell structured Fe 3O 4 nanoparticles (NPs) covalently functionalized with iminodiacetic acid (IDA) via click chemistry between the azide and alkyne groups and charged with Cu 2+. Firstly, the Fe 3O 4@SiO 2 NPs were obtained using tetraethoxysilane (TEOS) to form a silica shell on the surface of the Fe 3O 4 core. The azide group-modified Fe 3O 4@SiO 2 NPs were obtained by a sol-gel process using 3-azidopropyltriethoxysilane (AzPTES) as the silane agent. Fe 3O 4@SiO 2-N 3 was directly reacted with N-propargyl iminodiacetic via click chemistry, in the presence of a Cu(I) catalyst, to acquire the IDA-modified Fe 3O 4 NPs. Finally, through the addition of Cu 2+, the Fe 3O 4@SiO 2-IDA-Cu NP product was obtained. The morphology, structure and composition of the NPs were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The resulting NPs showed a strong magnetic response to an externally applied magnetic field, a high adsorption capacity and excellent specificity towards hemoglobin (Hb). In addition, the Fe 3O 4@SiO 2-IDA-Cu NPs can be used for the selective removal of abundant Hb protein in bovine and human blood samples. This journal is © 2012 The Royal Society of Chemistry.


Khan A.L.,Catholic University of Leuven | Li X.,CAS Dalian Institute of Chemical Physics | Vankelecom I.F.J.,Catholic University of Leuven
Journal of Membrane Science | Year: 2011

The miscibility and gas separation performance of Matrimid and sulfonated aromatic poly(ether ether ketone) (S-PEEK) blend membranes prepared by solution casting method were studied. A S-PEEK polymer with fixed degree of sulfonation was used for membrane synthesis. Both Matrimid and S-PEEK were physically miscible over the whole composition range, as confirmed by visual observation and DSC studies. The effect of variation in composition on gas permeability and selectivity of blend membranes was investigated. The gas permeability and selectivity values fall in between those of the individual polymers, varying systematically with variation of S-PEEK content in the blend. The effect of feed pressure on CO2 permeation was linked to CO2 plasticization of the membranes. The Matrimid component of the blend membrane was cross-linked with p-xylenediamine to improve the anti-plasticization properties of the blend. In order to further study the stability and potential industrial application of these membranes, they were tested at different conditions of feed pressure, temperature and CO2 feed concentration. © 2011 Elsevier B.V.


Zhao B.,University of New Mexico | Sun Z.,CAS Dalian Institute of Chemical Physics | Guo H.,University of New Mexico
Journal of the American Chemical Society | Year: 2015

Energy flow and sequestration at the state-to-state level are investigated for a prototypical four-atom reaction, H2 + OH' H + H2O, using a transition-state wave packet (TSWP) method. The product state distribution is found to depend strongly on the reactant vibrational excitation, indicating mode specificity at the state-to-state level. From a local-mode perspective, it is shown that the vibrational excitation of the H2O product derives from two different sources, one attributable to the energy flow along the reaction coordinate into the newly formed OH bond and the other due to the sequestration of the vibrational energy in the OH spectator moiety during the reaction. The analysis provided a unified interpretation of some seemingly contradicting experimental observations. It is further shown that the transfer of vibrational energy from the OH reactant to H2O product is gated by the transition state, accomplished coherently by multiple TSWPs with the corresponding OH vibrational excitation. © 2015 American Chemical Society.


Lahankar S.A.,Montana State University | Zhang J.,Montana State University | Minton T.K.,Montana State University | Minton T.K.,CAS Dalian Institute of Chemical Physics | McKendrick K.G.,Heriot - Watt University
Journal of the American Chemical Society | Year: 2014

The first quantum-state-resolved distributions over the full range of available product levels are reported for any isotopic variant of the elementary reaction of O(3P) with molecular hydrogen. A laser-detonation source was used to produce a hyperthermal oxygen-atom beam, which allowed for sufficient collision energy to surmount the reaction barrier. This beam was crossed by a supersonic beam of D2. The nascent OD products were detected by laser-induced fluorescence. OD rotational distributions in vibrational states v′ = 0, 1, and 2 at a collision energy of 25 kcal mol-1 are reported, together with distributions for the dominant product vibrational level, v′= 0, at lower collision energies of 20 and 15 kcal mol-1. The OD product is highly rotationally excited, to a degree that declines as expected for the higher vibrational levels or for reductions in the collision energy. The measured rovibrational distributions at the highest collision energy are in excellent agreement with previous theoretical predictions based on quantum scattering calculations on the triplet potential energy surfaces developed by Rogers et al. (J. Phys. Chem. A 2000, 104, 2308-2325). However, no significant OD spin-orbit preference was observed, in contrast to the predictions of most existing theoretical models of the non-adiabatic dynamics based on the widely used reduced-dimensional four-state model of Hoffmann and Schatz (J. Chem. Phys. 2000, 113, 9456-9465). Furthermore, a clear observed preference for OD π(A′) Λ-doublet levels is not consistent with a simple extrapolation of the calculated relative reaction cross sections on intermediate surfaces of 3A′ and 3A symmetry. © 2014 American Chemical Society.


Xu Y.,Nankai University | Yin X.-B.,Nankai University | He X.-W.,Nankai University | Zhang Y.-K.,Nankai University | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Biosensors and Bioelectronics | Year: 2015

The marriage of metal-organic frameworks (MOFs) and electrochemiluminescence (ECL) can combine their merits together. Designing ECL-active MOF with a high electron transfer capacity and high stability is critical for ECL emission. Here we reported the ECL from a redox-active MOF prepared from {Ru[4,4'-(HO2C)2-bpy]2bpy}2+ and Zn2+; a property of MOFs has not been reported previously. The MOF structure is independent of its charge and is therefore stable electrochemically. The redox-activity and well-ordered porous structure of the MOF were confirmed by its electrochemical properties and ECL emission. The high ECL emission indicated the ease of electron transfer between the MOF and co-reactants. Furthermore, the MOF exhibited permselectivity, charge selectivity, and catalytic selectivity along with a stable and concentration-dependent ECL emission toward co-reactants. ECL mechanism was proposed based on the results. The detection and recovery of cocaine in the serum sample was used to validate the feasibility of MOF- based ECL system. The information obtained in this study provides a better understanding of the redox properties of MOFs and their potential electrochemical applications. © 2014 Elsevier B.V.


Luo Y.-C.,National Taiwan University | Liu Y.-H.,National Taiwan University | Hung Y.,National Taiwan University | Liu X.-Y.,CAS Dalian Institute of Chemical Physics | Mou C.-Y.,National Taiwan University
International Journal of Hydrogen Energy | Year: 2013

Mesoporous silica supported cobalt boride (Co-B) catalysts are rationally designed for hydrogen generation in ammonia-borane hydrolysis reactions under ambient conditions. Cobalt boride catalysts are supported on three different mesoporous silica, including beta-zeolite seeded MCM-41 (Co@M41S) and traditional MCM-41 (Co@M41T) via chemical adsorption onto functionalized surface with 3-trihydroxysilylpropylmethylphosphonate (THPMP), and one-step co-precipitation into mesoporous silica framework (Co@M41C). Our preparation strategies provide two insights to the reactions: first, cobalt oxide species are intrinsically deposited as ultra-small nanoparticles (<2 nm) on mesoporous silica supports; subsequently the nanoparticles are converted to active Co-B catalysts by reduction with sodium borohydride (SB). Three catalysts exhibit significant differences in catalytic reactivities with hydrogen production rates ranked in an order of Co@M41S > Co@M41T > Co@M41C. Detailed analysis of the coordination environments from in situ X-ray absorption spectroscopy (XAS) results confirm reducibility in SB. Amorphous nature of Co-B catalysts are responsible for efficient catalytic activity in Co@M41S and Co@M41T. Ammonia temperature programmed desorption (NH3-TPD) demonstrates support acidity that correlates to the degree of high dispersity and effective reducibility to Co-B. Effects from catalyst sizes, reducibility in SB treatment and surface acidity are studied in detail to compare catalytic reactivities among three types of supports. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.


Wang X.,Zhejiang University | Jin Y.,Zhejiang University | He H.,Zhejiang University | Yang F.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Nanoscale | Year: 2013

Bandgap engineering and shape control are important and advantageous for potential applications involving colloidal ZnO nanocrystals. Here we demonstrate the syntheses of high quality alloyed CdxZn1-xO nanocrystals with well-defined shapes, from faceted particles to tetrapods and ultrathin nanowires. By comparing the optical bandgaps of the pure ZnO, Cd xZn1-xO and MgxZn1-xO nanocrystals with various dimensions, we conclude that bandgap engineering of colloidal ZnO nanocrystals via cadmium alloying effectively narrows the bandgaps. Our study may shed light on the design and syntheses of colloidal alloyed oxide nanocrystals with controlled band structures and shapes. © 2013 The Royal Society of Chemistry.


Zhong W.,Dalian Medical University | Zhang W.,Dalian Medical University | Wang S.,Dalian Medical University | Qin J.,CAS Dalian Institute of Chemical Physics
PLoS ONE | Year: 2013

In native fibrocartilage, mechanotransduction allows the cells to perceive the physical microenvironment not only through topographical cues from the extracellular matrix, but also through mechanical cues, such as interstitial flow. To create a microenvironment that simultaneously integrates nanotopography and flow stimulus, we developed a biomimetic microfluidic device embedded with aligned nanofibers to contain microchambers of different angles, which enabled the flow direction to form different angles with the fibers. Using this device, we investigated the effects of microfluidic and nanotopographical environment on the morphology and fibrochondrogenesis of mesenchymal stem cells (MSCs) and the involvement of RhoA/ROCK pathway and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). The results showed that the flow direction perpendicular to aligned nanofibers was conducive to fibrochondrogenesis of MSCs. In addition, ROCK inhibitor and knockdown of YAP/TAZ disrupted fibrochondrogenic differentiation of MSCs. In conclusion, our data suggest the crucial role of mechanotransduction in regulating fibrochondrogenic differentiation of MSCs, which may be mediated by RhoA/ROCK pathway and YAP/TAZ. © 2013 Zhong et al.


Xiao J.,Nanyang Technological University | Xiao J.,CAS Dalian Institute of Chemical Physics | Lu Y.-P.,Nanyang Technological University | Liu Y.-L.,Nanyang Technological University | And 2 more authors.
Organic Letters | Year: 2011

A new class of chiral secondary amine organocatalyst was rationally designed as an efficient catalyst to catalyze the elusive Michael addition of aldehydes to vinyl sulfones. High yield and excellent enantioselectivities could be obtained at room temperature without having to resort to high catalyst loading, anhydrous solvents, and low temperatures. Efficient control of enamine conformation and face shielding as well as the rigid nature of the tricyclic skeleton, with an inherent chiral pocket, provide a well-organized chiral environment to effect this elusive reaction efficiently.(Figure Presented) © 2011 American Chemical Society.


Too P.C.,Nanyang Technological University | Noji T.,Tohoku University | Lim Y.J.,Nanyang Technological University | Li X.,CAS Dalian Institute of Chemical Physics | Chiba S.,Nanyang Technological University
Synlett | Year: 2011

A method for the synthesis of highly substituted pyri-dines from ,-unsaturated oximes and internal alkynes has been developed using [Cp*RhCl2]2-CsOPiv as the catalyst system. The present transformation is carried out by a redox-neutral sequence of vinylic C-H rhodation, alkyne insertion, and C-N bond formation of the putative vinyl rhodium intermediate with the oxime nitrogen, where the N-O bond of oxime derivatives could work as an internal oxidant to maintain the catalytic cycle. © Georg Thieme Verlag Stuttgart · New York.


Hou C.,Anhui Polytechnic University | Hou C.,CAS Dalian Institute of Chemical Physics
Computational and Theoretical Chemistry | Year: 2014

A quantum mechanical approach has been used to shed light on the antioxidative mechanism for scavenging OOH and OH radicals by norathyriol in the solution phase. Density functional theory (DFT) calculations at the B3LYP and UB3LYP/6-311+G(d,p) level are used to optimize norathyriol and its different radical forms. Analysis of the theoretical bond dissociation enthalpy (BDE) values for all OH sites of norathyriol in solution clearly shows the importance of the B-ring and the 6-OH and 7-OH groups in the antioxidant activity. We have also investigated the spin density of the radicals to determine the delocalization possibilities. The results of the calculations show that the oxidation of norathyriol by both the OOH and OH radical is an exothermic reaction. In all calculations solvent effects are considered using a polarized continuum model (PCM). © 2013 Elsevier B.V.


Feng L.,Liaoning University of Technology | Feng L.,CAS Dalian Institute of Chemical Physics
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

Molecular high-order harmonic generation from the H2+ ion driven by spatial inhomogeneous fields consisting of the chirped pulse and a terahertz pulse has been theoretically investigated by numerically solving the non-Born-Oppenheimer time-dependent Schrödinger equation. It shows that with the introduction of the chirp as well as the spatial inhomogeneity of the pulse, not only the harmonic cutoff is remarkably extended, but also the single short quantum path is selected to contribute to the harmonic spectra. Moreover, through investigation the effects of the laser and the molecular parameters on the inhomogeneous harmonic generation, we found 1.92- and 3.3-dB enhanced fields for the chirp-free and chirped inhomogeneous pulses, respectively. Isotopic effect shows that intense harmonics can be generated from the lighter molecule. Furthermore, with the enhancement of the initial vibrational state and by properly adding a terahertz controlling pulse, the harmonic yield is enhanced by almost five orders of magnitude compared with the initial single chirped case. As a result, a 362-eV supercontinuum (which corresponds to a 4.0-dB laser field enhancement) with five orders of magnitude improvement is obtained. Finally, by properly superposing the harmonics, a series of intense extreme ultraviolet pulses with durations from 22 to 52 as can be produced. © 2015 American Physical Society.


Su D.S.,CAS Shenyang Institute of Metal Research | Su D.S.,Fritz Haber Institute of the Max Planck Society | Sun G.,CAS Dalian Institute of Chemical Physics
Angewandte Chemie - International Edition | Year: 2011

Within reach: Newly developed nonprecious-metal catalysts can be used to produce inexpensive hydrogen fuel cells with performances approaching those of platinum-based systems. For example, the best non-Pt catalyst was prepared from a metal-organic framework consisting of zeolitic Zn II imidazolate which served as the host for the Fe and N precursors of the catalyst. The plot shows the volumetric current densities of the best non-Pt catalysts and the target value set by the U.S. DOE at 0.8 V). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Provencher B.A.,Brandeis University | Bartelson K.J.,Brandeis University | Liu Y.,Brandeis University | Liu Y.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2011

Unprecedented phase-transfer catalysts for the first example of an organocatalytic asymmetric conjugate addition of cyanide with acetone cyanohydrin are reported (see scheme). Utilizing an accessible cupreidinium salt and a cyanation reagent suitable for industrial scale, this reaction holds significant promise for practical asymmetric synthesis. The catalysts were developed as a result of key structural insights gained by X-ray analysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Shan Y.,Flinders University | Shan Y.,CAS Dalian Institute of Chemical Physics | Zhang W.,Flinders University
Journal of Separation Science | Year: 2010

Mangosteen fruit pericarp (MFP) is a rich source of xanthones, which has shown remarkable pharmacological activities. To isolate xanthones, previous methods included labor intensive and time-consuming solid-phase extractions (Sephadex LH20, silica gel) and sequential solvent extraction. In this study, major xanthones (α- and γ-mangostins) in MFP were isolated at high purity in one step utilizing high-performance centrifugal partition chromatography with solvent system composed of petroleum ether, ethyl acetate, methanol and water (10:5:5:1). In one run, 200 mg crude extract of MFP was injected and 55.4 mg α-mangostin and 12.4 mg g-mangostin were obtained with the purity of 93.6 and 98.4%, respectively. The yields of them were 86.3 and 76.3%, respectively. As α- and γ-mangostins are reported to show potent antioxidant, anti-inflammatory and anticancer activities, this method can be used for the large-scale production of them for future in vitro and in vivo biological studies. & 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Qu Z.,Dalian University of Technology | Miao L.,Dalian University of Technology | Wang H.,Dalian University of Technology | Fu Q.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2015

Highly dispersed Fe2O3 nanoparticles supported on carbon nanotubes, prepared by a simple ethanol-assisted impregnation method, showed above 90% NO conversion and selectivity at low temperatures (200-325 °C). Moreover excellent durability and stability towards SO2/H2O was obtained. This journal is © The Royal Society of Chemistry 2015.


Hao D.,Dalian Jiaotong University | Yang L.,CAS Dalian Institute of Chemical Physics | Xiao P.,Chinese Academy of Sciences
Molecular Genetics and Genomics | Year: 2011

Taxus mairei is a critically endangered and commercially important cultured medicinal gymnosperm in China and forms an important medicinal resource, but the research of its genome is absent. In this study, we constructed a T. mairei fosmid library and analyzed the fosmid end sequences to provide a preliminary assessment of the genome. The library consists of one million clones with an average insert size of about 39 kb, amounting to 3.9 genome equivalents. Fosmid stability assays indicate that T. mairei DNA was stable during propagation in the fosmid system. End sequencing of both 5′ and 3′ ends of 968 individual clones generated 1,923 sequences after trimming, with an average sequence length of 839 bp. BLASTN searches of the nr and EST databases of GenBank and BLASTX searches of the nr database resulted in 560 (29.1%) significant hits (E < e-5). Repetitive sequences analysis revealed that 20.8% of end sequences are repetitive elements, which were composed of retroelements, DNA transposons, satellites, simple repeats, and low complexity sequences. The distribution pattern of various repeat types was found to be more similar to the gymnosperm Pinus and Picea than to the monocot and dicot. The satellites of T. mairei were significantly longer than those of P. taeda and P. glauca. The tetra-nucleotide repeats of T. mairei were much longer than those of P. glauca and P. taeda. The fosmid library and the fosmid end sequences, for the first time, will serve as a useful resource for large-scale genome sequencing, physical mapping, SSR marker development and positional cloning, and provide a better understanding of the Taxus genome. © 2010 Springer-Verlag.


Feng L.,University of Illinois at Urbana - Champaign | Feng L.,CAS Dalian Institute of Chemical Physics | Musto C.J.,University of Illinois at Urbana - Champaign | Suslick K.S.,University of Illinois at Urbana - Champaign
Journal of the American Chemical Society | Year: 2010

A colorimetric detection method using amine-functionalized polymer films doped with a pH indicator has been developed for the rapid, sensitive, and quantitative detection of gaseous formaldehyde at concentrations well below the immediately dangerous to life or health (IDLH) limit. In 1 min, visible color changes are easily observed, even down to the permissible exposure limit (PEL) at 750 ppb. The limit of detection is below 50 ppb (7% of the PEL) after 10 min of exposure. This sensor is essentially unaffected by changes in humidity or temperature (4 to 50 °C) and is not sensitive to common interferents. Copyright © 2010 American Chemical Society.


Tao L.,CAS Dalian Institute of Chemical Physics
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2010

The C-H activation may be defined as reaction that cleavages a C-H bond. It is of significance to explore the mechanism of C-H activation of methane dehydro-aromatization in the absence of gaseous oxygen and to understand how the key intermediates originate. The C-H activation of methane was discussed in terms of carbonium ion mechanism and free-radical mechanism. According to now widely accepted mechanism, an acidic catalyst protonates an alkane to give carbonium ion transition state. Methane is first protonated to the penta-coordinate carbonium ion type transition state CH5+ (Methonium ion), which is easily converted into the trivalent carbenium ion CH3+ (Methenium ion). On the basis of carbonium ion mechanism and hydride transfer reaction, it is followed with interest that C-H of methane can be highly activated by hydride-transfer reaction with co-reactant alkene in the presence of bifunctional catalysts. In addition to carbonium ion mechanism, the contribution of free-radical mechanism can not be neglected in methane dehydro-aromatization. Heterolysis of a C-H bond by hydride transfer leads to methyl cation, and C-H bond homolysis occurring as H-atom abstraction leads to methyl radical. According to mechanism of noncatalytic free-radical-type thermal reaction, free-radical and carbene may act as the active intermediates. Carbene is the important intermediate of methane dehydro-aromatization in addition to carbonium ion. Methenium ion formed from heterolytic cleavage of a C-H bond of methane is rapidly decomposed and releases the proton and carbene. The former is given back to the zeolite and the latter is rapidly dimerized. Carbenes can undergo insertion into a C-H bond. The mechanism of the insertion reaction depends on whether the carbene is a singlet or a triplet. The Mo/zeolites is a bifunctional catalyst with acid sites as well as dehydrogenation functions. CH4 reactions require initial activation of CH4 on MoOx. The MoOx species can be partially reduced to the Mo oxycarbide species (MoOxCy) or fully reduced into the Mo carbide species (Mo2C), depending on the different interaction between Mo oxide species and Brönsted acid sites of zeolite. The C-H activation of methane is suggested to occur under concerted catalysis of Mo oxycarbide (carbide) species and protons.


Wu X.,CAS Institute of Botany | Wu X.,Wenzhou Medical College | Wu X.,CAS Dalian Institute of Chemical Physics | Song Y.,Wenzhou Medical College
BMC Genomics | Year: 2011

Background: microRNAs (miRNAs) represent a class of small (typically 22 nucleotides in length) non-coding RNAs that can degrade their target mRNAs or block their translation. Recent disease research showed the exposure to some environmental chemicals (ECs) can regulate the expression patterns of miRNAs, which raises the intriguing question of how miRNAs and their targets cope with the exposure to ECs throughout the genome.Results: In this study, we comprehensively analyzed the properties of genes regulated by ECs (EC-genes) and found miRNA targets were significantly enriched among the EC-genes. Compared with the non-miRNA-targets, miRNA targets were roughly twice as likely to be EC-genes. By investigating the collection methods and other properties of the EC-genes, we demonstrated that the enrichment of miRNA targets was not attributed to either the potential collection bias of EC-genes, the presence of paralogs, longer 3'UTRs or more conserved 3'UTRs. Finally, we identified 1,842 significant concurrent interactions between 407 miRNAs and 497 ECs. This association network of miRNAs-ECs was highly modular and could be separated into 14 interconnected modules. In each module, miRNAs and ECs were closely connected, providing a good method to design accurate miRNA markers for ECs in toxicology research.Conclusions: Our analyses indicated that miRNAs and their targets played important roles in cellular responses to ECs. Association analyses of miRNAs and ECs will help to broaden the understanding of the pathogenesis of such chemical components. © 2011 Wu and Song; licensee BioMed Central Ltd.


Bux H.,Leibniz University of Hanover | Feldhoff A.,Leibniz University of Hanover | Cravillon J.,Leibniz University of Hanover | Wiebcke M.,Leibniz University of Hanover | And 2 more authors.
Chemistry of Materials | Year: 2011

A highly oriented zeolitic imidazolate framework 8 (ZIF-8) composite membrane was prepared by seeding and secondary growth. By dip-coating, preformed ZIF-8 nanocrystals were attached to the surface of a porous α-alumina support using polyethyleneimine as the coupling agent. After solvothermal treatment, a continuous and well-intergrown ZIF-8 layer was obtained. X-ray diffraction analysis of the membrane showed preferred orientation of the {100} plane parallel to the support. Further time-dependent investigations by scanning and transmission electron microscopy as well as X-ray diffraction indicated that the preferred orientation develops during an evolutionary growth process. In gas mixture permeation experiments, the membrane showed good performance in H2/hydrocarbon separation. A sharp molecular sieve separation is observed for an equimolar H2/C3H8 mixture with a separation factor above 300. © 2011 American Chemical Society.


Meng Q.,CAS Dalian Institute of Chemical Physics | Meyer H.-D.,University of Heidelberg
Journal of Chemical Physics | Year: 2014

Employing the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method in conjunction with the multistate multimode vibronic coupling Hamiltonian (MMVCH) model, we perform a full dimensional (9D) quantum dynamical study on the simplest Criegee intermediate, formaldehyde oxide, in five lower-lying singlet electronic states. The ultraviolet (UV) spectrum is then simulated by a Fourier transform of the auto-correlation function. The MMVCH model is built based on extensive MRCI(8e,8o)/aug-cc-pVTZ calculations. To ensure a fast convergence of the final calculations, a large number of ML-MCTDH test calculations is performed to find an appropriate multilayer separations (ML-trees) of the ML-MCTDH nuclear wave functions, and the dynamical calculations are carefully checked to ensure that the calculations are well converged. To compare the computational efficiency, standard MCTDH simulations using the same Hamiltonian are also performed. A comparison of the MCTDH and ML-MCTDH calculations shows that even for the present not-too-large system (9D here) the ML-MCTDH calculations can save a considerable amount of computational resources while producing identical spectra as the MCTDH calculations. Furthermore, the present theoretical \documentclass[12pt]{minimal}\begin{document}$\tilde{B}\:{}1A{\prime }\leftarrow \tilde{X}\:{}1A{\prime }$\end{document}B∼;1A′←X∼1A′ UV spectral band and the corresponding experimental measurements [J. M. Beames, F. Liu, L. Lu, and M. I. Lester, J. Am. Chem. Soc. 134, © 2014 AIP Publishing LLC.


Li L.,CAS Yantai Institute of Coastal Zone Research | Li L.,Qinghai Academy of Agriculture and Forestry Research | Wang Y.,CAS Yantai Institute of Coastal Zone Research | Du Y.,CAS Dalian Institute of Chemical Physics | Qin S.,CAS Yantai Institute of Coastal Zone Research
Biotechnology Letters | Year: 2013

The polysaccharides in Jerusalem artichoke (JA) carry a substantial amount of energy that can be partly accessed through bioconversion into storable fuels. We review the potential for converting inulin into a variety of high value-added biorefinery products, including biofuels and biochemicals, and consider the feasibility of regarding JA as a model species of an inulin-rich crop. We discuss feedstock pretreatment, microorganisms used during fermentation, biorefinery products derived from JA, and how to enhance the economic competitiveness of JA as an energy crop. © 2012 Springer Science+Business Media Dordrecht.


Lin R.,Dalian National Laboratory for Clean Energy | Ding Y.,Dalian National Laboratory for Clean Energy | Ding Y.,CAS Dalian Institute of Chemical Physics
Materials | Year: 2013

Considerable efforts have been devoted to extending the range of the elemental composition of mesoporous materials since the pioneering work of the M41S family of ordered mesoporous silica by Mobil researchers. The synthesis of transition metal-containing mesostructured materials with large surface area and high porosity has drawn great attention for its potential applications in acid and redox catalysis, photocatalysis, proton conducting devices, environmental restoration and so on. Thus, various transition metals-containing mesoporous materials, including transition metal-substituted mesoporous silicates, mesostructured transition metal oxides and transition metal phosphates (TMP), have been documented in the literature. Among these, mesostructured TMP materials are less studied, but possess some unique features, partly because of the easy and facile functionalization of PO4 and/or P-OH groups, rendering them interesting functional materials. This review first introduced the general synthesis strategies for manufacturing mesostructured TMP materials, as well as advantages and disadvantages of the respective method; then, we surveyed the ongoing developments of fabrication and application of the TMP materials in three groups on the basis of their components and application fields. Future perspectives on existing problems related to the present synthesis routes and further modifying of the functional groups for the purpose of tailoring special physical-chemical properties to meet wide application requirements were also provided in the last part. © 2013 by the authors; licensee MDPI, Basel, Switzerland.


Zhao J.,CAS Dalian Institute of Chemical Physics | Zhao J.,Dalian University of Technology
Journal of Chemical Physics | Year: 2013

We investigated spin-orbit-induced intersystem crossing effects in the title reaction by the time-dependent wave-packet method combined with an extended split operator scheme. We performed non-adiabatic calculations of the fine-structure-resolved cross section and adiabatic calculations of integral cross section. The calculations are based on the potential energy surfaces of 3A' and the two degenerate 3A'' states [S. Rogers, D. Wang, A. Kuppermann, and S. Walch, J. Phys. Chem. A 104, 2308 (2000)]10.1021/jp992985g, together with the spin-orbit coupling matrix [B. Maiti and G. C. Schatz, J. Chem. Phys. 119, 12360 (2003)]10.1063/1.1623481 and singlet 1A' potential energy surface [J. Dobbyn and P. J. Knowles, Faraday Discuss. 110, 247 (1998)]. The results of the O(3P)+ D 2 are similar to those of the O(3P)+ H2 reaction. The product spin state-resolved reaction cross section and the total reaction cross section both show that the adiabatic channel is dominant in all cases, and the non-adiabatic channels have cross sections of several orders of magnitude smaller than the adiabatic channels at high collision energy. Although the cross sections caused by the intersystem crossing effects in the O( 3P) +D2 reaction are larger than those in the O( 3P)+2 reaction, the differences in non-adiabaticity between these two reaction systems are quite modest. Based on the results of the O(3P) +H2 reaction, we can predict that the influence of spin-orbit on the total reaction cross sections of the O(3P)+ D 2 reaction is also insignificant. However, these non-adiabatic effects can be reflected in the presence of some forward-scattering in the angular distribution for the OD product. © 2013 American Institute of Physics.


Li A.,University of New Mexico | Guo H.,University of New Mexico | Sun Z.,CAS Dalian Institute of Chemical Physics | Klos J.,University of Maryland University College | Alexander M.H.,University of Maryland University College
Physical Chemistry Chemical Physics | Year: 2013

The state-to-state reaction dynamics of the title reaction is investigated on the ground electronic state potential energy surface using two quantum dynamical methods. The results obtained using the Chebyshev real wave packet method are in excellent agreement with those obtained using the time-independent method, except at low translational energies. It is shown that this exothermic hydrogen abstraction reaction is direct, resulting in a strong back-scattered bias in the product angular distribution. The HF product is highly excited internally. Agreement with available experimental data is only qualitative. We discuss several possible causes of disagreement with experiment. This journal is © 2013 the Owner Societies.


Xu G.,CAS Dalian Institute of Chemical Physics | Wang W.,Dongbei University of Finance and Economics
Journal of Natural Gas Chemistry | Year: 2010

Abstract Ensuring a sufficient energy supply is essential to a country. Natural gas constitutes a vital part in energy supply and therefore forecasting natural gas consumption reliably and accurately is an essential part of a country's energy policy. Over the years, studies have shown that a combinative model gives better projected results compared to a single model. In this study, we used Polynomial Curve and Moving Average Combination Projection (PCMACP) model to estimate the future natural gas consumption in China from 2009 to 2015. The new proposed PCMACP model shows more reliable and accurate results: its Mean Absolute Percentage Error (MAPE) is less than those of any previous models within the investigated range. According to the PCMACP model, the average annual growth rate will increase for the next 7 years and the amount of natural gas consumption will reach 171600 million cubic meters in 2015 in China. © 2010 CAS/DICP.


Yang F.,Nankai University | Mao J.,Nankai University | He X.W.,Nankai University | Chen L.X.,Nankai University | And 2 more authors.
Analytical and Bioanalytical Chemistry | Year: 2013

A novel strategy for preparation of a boronate affinity hybrid monolith was developed using a Cu(I)-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) reaction of an alkyne-boronate ligand with an azide-functionalized monolithic intermediate. An azide-functionalized hybrid monolith was first synthesized via a single-step procedure to provide reactive sites for click chemistry; then the alkyne-boronate ligands were covalently immobilized on the azide-functionalized hybrid monolith via an in-column CuAAC reaction to form a boronate affinity hybrid monolith under mild conditions. The boronate affinity monolith was characterized and evaluated by means of elemental analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The boronate affinity hybrid monolith exhibited excellent specificity toward nucleosides and glycoproteins, which were chosen as test cis-diol-containing compounds under neutral conditions. The binding capacity of the monolith for the glycoprotein ovalbumin was 2.36 mg · g-1 at pH 7.0. The practicability of the boronate affinity hybrid monolithic material was demonstrated by specific capture of the glycoproteins ovalbumin and ovotransferrin from an egg sample. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg.


Yang M.-J.,CAS Dalian Institute of Chemical Physics | Zhang X.,Scripps Research Institute
Proteins: Structure, Function and Bioinformatics | Year: 2011

Two homologous GTPases (guanine-triphosphatases) in the signal recognition particle (SRP) and its receptor (SR) use their cumulative energy during GTP (guanine-triphosphate) hydrolysis to control the co-translational protein targeting process. Distinct from classical GTPases, which rely on external factors to hydrolyze GTP, SRP GTPases stimulate one another's activity in a self-sufficient manner upon SRP-SR complex association. Although both ground-state and putative transition-state GTP analogs have been used to recapitulate the state of GTPase activation, the underlying mechanism of the activated state still remains elusive. In particular, several residues that were placed in pending positions have been shown to be important to GTP hydrolysis in biochemical studies. Here, we examined the stability and dynamics of three interaction networks involving these residues and discovered that they contribute to the GTPase activation via well-tuned conformational changes. The crystallographically identified pending residues Ffh:R191/FtsY:R195 undergo extensive conformational rearrangements to form persisted interactions with FtsY:E284/Ffh:E274, explaining the biochemically observed defective effect of R191 mutant to the activation of both GTPases. In addition, the side chain of FtsY:R142, one of the most important catalytic residues, rotates to an extended conformation that could more efficiently maintain the electrostatic balance for GTP hydrolysis. Finally, the invariant residues Ffh:G190 and FtsY:G194, instead of the supposed auxiliary water molecules, are proposed to stabilize the nucleophilic waters during GTPase activation. In complementary to experimental observations, these findings suggest a more favorable interaction model for SRP GTPase activation and would thus benefit to our understanding of how SRP GTPases regulate the protein targeting pathway. © 2011 Wiley-Liss, Inc.


Cao J.,Nankai University | Zhang X.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Journal of Materials Chemistry B | Year: 2013

In this study, a facile and efficient separation of abundant proteins from bovine blood using core-shell structure nanoparticles with a magnetic core and an immobilized metal affinity ligand iminodiacetic acid (IDA) chelating Ni(ii) is presented. Firstly, Fe3O4 magnetic nanoparticles (MNPs) were synthesized through a solvothermal method and then were conveniently surface-modified with 3-(methacryloyloxy) propyltrimethoxylsilane as anchor molecules to donate vinyl groups. Next a high density poly(4- vinylbenzylchloride) (PVBC) shell was synthesized on the surface of silica-coated Fe3O4 MNPs via distillation-precipitation polymerization. After the PVBC shell reacted with iminodiacetic acid (IDA) in alkaline aqueous solution, the magnetite was charged with Ni2+ to form Ni(ii)-IDA functionalized hybrid Fe3O4@PVBC@IDA-Ni MNPs. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and a vibrating sample magnetometer (VSM) were employed to evaluate the size, morphology and magnetic property of the resulting magnetic nanospheres. The high saturation magnetization (48.1 emu g-1) provides the materials with the convenience of magnetic separation under an external magnetic field and they can be subsequently reused. The core-shell Fe3O4@PVBC@IDA-Ni MNPs exhibit excellent performance in the separation of protein bovine hemoglobin (BHb), and the binding capacity is as high as 1988 mg g-1. In addition, the Fe 3O4@PVBC@IDA-Ni MNPs can be used in selective removal of abundant protein Hb in the bovine blood samples. This opens a novel route for its future application in removing abundant protein in proteomic analysis. © 2013 The Royal Society of Chemistry.


Wang N.,Dalian University of Technology | Wang N.,Henan University of Technology | Wang M.,Dalian University of Technology | Wang Y.,KTH Royal Institute of Technology | And 5 more authors.
Journal of the American Chemical Society | Year: 2013

A [FeFe]-hydrogenase model (1) containing a chelating diphosphine ligand with a pendant amine was readily oxidized by Fc+ (Fc = Cp 2Fe) to a FeIIFeI complex ([1]+), which was isolated at room temperature. The structure of [1]+ with a semibridging CO and a vacant apical site was determined by X-ray crystallography. Complex [1]+ catalytically activates H2 at 1 atm at 25 C in the presence of excess Fc+ and P(o-tol) 3. More interestingly, the catalytic activity of [1]+ for H2 oxidation remains unchanged in the presence of ca. 2% CO. A computational study of the reaction mechanism showed that the most favorable activation free energy involves a rotation of the bridging CO to an apical position followed by activation of H2 with the help of the internal amine to give a bridging hydride intermediate. © 2013 American Chemical Society.


Wei Y.,South China University of Technology | Yang W.,CAS Dalian Institute of Chemical Physics | Caro J.,Leibniz University of Hanover | Wang H.,South China University of Technology
Chemical Engineering Journal | Year: 2013

A dense ceramic oxygen permeable membrane reactor (OPMR) not only combines a membrane separation unit with a chemical reaction, but couples them in such a way that a synergy is created between the two units. This technical concept is expected to be a promising approach to achieve green and sustainable chemistry with less energy consumption and lower pollution. This article presents a review of the recent progress of dense ceramic OPMR, including membrane materials, membrane architecture, membrane reactor design, new applications in energy and environmental fields, current challenges related to industrialization and future research. © 2013 Elsevier B.V.


Chen W.,Shenyang Ligong University | Liu Y.,Shenyang Ligong University | Xin Q.,CAS Dalian Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2010

A polymer-graphite composite bipolar plate of direct methanol fuel cell (DMFC) was fabricated by a compression molding method. The electrical conductivity and electrochemical behavior of the composite material under DMFC operating conditions were evaluated. The results show that the composite bipolar plate has a good electrical conductivity. Moreover, the through-plane conductivity of the composite material is higher than the in-plane one, which is ascribed to the anisotropic property of the composite bipolar plate resulted from the compression molding process. Corrosion tests show that the stable current density is below 10 μA cm-2 under both anode and cathode conditions of DMFC. The discharge test of the DMFC single cell also presents a satisfactory result. © 2010 Professor T. Nejat Veziroglu.


Nan Z.,Yangzhou University | Tan Z.,CAS Dalian Institute of Chemical Physics
Journal of Chemical and Engineering Data | Year: 2011

An n-butanol-based nanofluid containing nanowire-shaped β-FeOOH was synthesized by a solvothermal method. The nanofluid was stable for 7 days without any precipitation with 3.0 mM SDBS as stabilizer. Uniform β-FeOOH nanowires with high aspect ratios were fabricated. The heat capacities of the obtained β-FeOOH sample, the base fluid, and the nanofluid were determined by an adiabatic calorimeter. Smoothed heat capacities and thermodynamic functions of the obtained samples, such as H(T/K) - H(298.15 K) and S(T/K) - S(298.15 K), were calculated based on the fitted polynomials and the relationships of the thermodynamic functions. These results are very useful to apply to the as-produced nanowire-shaped β-FeOOH and the nanofluid in engineering fields. © 2010 American Chemical Society.


Yu C.,Jiangxi University of Science and Technology | Xu H.,CAS Dalian Institute of Chemical Physics
Separation and Purification Technology | Year: 2011

An efficient palladium membrane was employed for hydrogen separation in lab-scale membrane reactor during the process of catalytic dehydrogenation of ethylbenzene to styrene. Compared with the conventional fixed bed reactor, the effects of reaction conditions including pressure, space velocity and temperatures on the ethylbenzene conversion and selectivity to styrene in the membrane reactor were investigated. It was found that the efficient removal of hydrogen in the membrane reactor could significantly increase the ethylbenzene conversion without at the expense of styrene selectivity. Under the optimal reaction conditions, 11.3% enhancement in yield to styrene was obtained in the membrane reactor. © 2011 Elsevier B.V. All rights reserved.


Zhou X.-Y.,Dalian University of Technology | Bao M.,Dalian University of Technology | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Advanced Synthesis and Catalysis | Year: 2011

Using a catalytic amount of a Brønsted acid as activator of simple imines, the highly enantioselective homogeneous palladium-catalyzed asymmetric hydrogenation of simple ketimines was successfully developed with up to 95% ee. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Gao R.,Nankai University | Su X.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Talanta | Year: 2011

This paper reports the preparation of carbon nanotubes (CNTs) functionalized with molecularly imprinted polymers (MIPs) for advanced removal of estrone. CNTs@Est-MIPs nanocomposites with a well-defined core-shell structure were obtained using a semi-covalent imprinting strategy, which employed a thermally reversible covalent bond at the surface of silica-coated CNTs for a large-scale production. The morphology and structure of the products were characterised by transmission electron microscopy and Fourier transform infrared spectroscopy. The adsorption properties were demonstrated by equilibrium rebinding experiments and Scatchard analysis. The results demonstrate that the imprinted nanocomposites possess favourable selectivity, high capacity and fast kinetics for template molecule uptake, yielding an adsorption capacity of 113.5 μmol/g. The synthetic process is quite simple, and the different batches of synthesized CNTs@Est-MIPs nanocomposites showed good reproducibility in template binding. The feasibility of removing estrogenic compounds from environmental water using the CNTs@Est-MIPs nanocomposites was demonstrated using water samples spiked with estrone. © 2010 Elsevier B.V. All rights reserved.


Schwenzer B.,Pacific Northwest National Laboratory | Zhang J.,CAS Dalian Institute of Chemical Physics | Kim S.,Pacific Northwest National Laboratory | Li L.,Pacific Northwest National Laboratory | And 2 more authors.
ChemSusChem | Year: 2011

Large-scale energy storage has become the main bottleneck for increasing the percentage of renewable energy in our electricity grids. Redox flow batteries are considered to be among the best options for electricity storage in the megawatt range and large demonstration systems have already been installed. Although the full technological potential of these systems has not been reached yet, currently the main problem hindering more widespread commercialization is the high cost of redox flow batteries. Nafion, as the preferred membrane material, is responsible for about 11% of the overall cost of a 1 MW/8MWh system. Therefore, in recent years two main membrane-related research threads have emerged: 1) chemical and physical modification of Nafion membranes to optimize their properties with regard to vanadium redox flow battery (VRFB) application; and 2) replacement of the Nafion membranes with different, less expensive materials. This review summarizes the underlying basic scientific issues associated with membrane use in VRFBs and presents an overview of membrane-related research approaches aimed at improving the efficiency of VRFBs and making the technology cost-competitive. Promising research strategies and materials are identified and suggestions are provided on how materials issues could be overcome. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhuo R.,CAS Dalian Institute of Chemical Physics
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2010

A method of hydrophilic interaction chromatography (HILIC) was established for the quantitative determination of trigonelline in Trigonella foenum-graecum L. HILIC analysis was performed on a Waters Atlantis HILIC Silica column (150 mm x 2.1 mm, 3 microm). The mobile phase consisted of acetonitrile-ammonium acetate (pH 4.4) (70:30, v/v), and the flow rate was 0. 4 mL/min. The detection wavelength was set at 265 nm. The method has good linearity in the range of 2.50-100 mg/L for trigonelline (r = 0.999 6). The recoveries were on an average of 102% by adding 29.2 mg/L and 43.8 mg/L with relative standard deviations (RSDs) of 4.17% and 2.28% (n = 3), respectively. The results indicate that the method is simple and rapid for the determination of strong polar trigonelline in Trigonella foenum-graecum L. Furthermore, it significantly reduces the equilibration time compared with ion-pair liquid chromatography (IPLC) recorded in the Pharmacopoeia of China. This new method can be used as a valid method for the quality control of Trigonella foenum-graecum L.


Jun E.J.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | Lee M.,Ewha Womans University | Yoon J.,Ewha Womans University
Tetrahedron Letters | Year: 2013

A new ratiometric fluorescent probe for fluoride ions was developed which complexed fluoride by a tridentate receptor of boronic acid and imidazolium. In the current study, a tridentate receptor 1 with one ortho boronic acid and two imidazolium groups was designed. The boron center can co-operate with imidazolium to bind F-. The formation of B-F complex stabilizes the interaction between fluoride and imidazolium which induces a ratiometric fluorescence response. With the addition of F-, a strongly increased fluorescent emission centered at 370 nm appears at the expense of the fluorescent emission centered at 445 nm. © 2013 Elsevier Ltd.All rights reserved.


Zhang T.,South-Central University for Nationalities | Wu L.,South-Central University for Nationalities | Li X.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2013

Rh(III)-catalyzed olefination of N-sulfonyl imines using acrylates and styrenes has been achieved for the synthesis of ortho-olefinated benaldehydes. This reaction proceeds via a chelation assisted C-H olefination/in situ hydrolysis process. © 2013 American Chemical Society.


Zhang F.,Nankai University | He X.-W.,Nankai University | Li W.-Y.,Nankai University | Zhang Y.-K.,Nankai University | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2012

In the last two decades, near-infrared (NIR) emitting Cu-doped quantum dots (QDs) have stimulated stupendous research interest for their excellent optical properties. Due to the synthetic method in the organic phase, almost none of the NIR emitting Cu-doped QDs were used as the fluorescent probes for biological imaging, despite being employed for applications in many fields. In this work, we successfully synthesized water-soluble Cu-doped CdS quantum dots (Cu:CdS d-dots) with an emission wavelength at 722 nm using a fast and facile hydrothermal method. The optical properties of the d-dots and several key parameters of the synthesis conditions such as dopant concentration, reaction temperature, reflux time, and especially the pH of the reaction mixture were systematically studied, and the mechanism of these parameters is also discussed. A red shift of the emission maximum as a consequence of the increased reaction temperature was observed, but it does not move to the NIR region until Cu 2+ is doped even at the highest reflux temperature in aqueous solution. The d-dots have good water solubility and biocompatibility for successful labeling the living HeLa cells as fluorescence probe. © 2012 The Royal Society of Chemistry.


Zhang X.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | Zhang Y.,Nankai University | Zhang Y.,CAS Dalian Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2012

In this study, a novel approach was developed to synthesize aminophenylboronic acid functionalized magnetic nanoparticles (NPs) via Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) 'click' chemistry. Firstly, azide-functional Fe 3O 4 NPs were obtained by a two-step chemical modification process. Then, an alkyne-phenylboronic acid molecule was connected onto the surface of magnetite by the CuAAC reaction. The morphology, structure and composition of the synthesized nanocomposites were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectrometry (XPS). Five proteins, including ovalbumin (OB), transferrin (Trf), as glycoprotein templates and lysozyme (Lyz), bovine serum albumin (BSA), horse heart cytochrome c (Cyt C) as nonglycoprotein templates are chosen as target proteins. The as-prepared click-Fe 3O 4@APBA NPs with a mean diameter of 23.2 nm showed a strong magnetic response to an externally applied magnetic field and exhibited a high adsorption capacity and excellent specificity towards glycoproteins in comparison with nonglycoproteins. The click-Fe 3O 4@APBA NPs showed the higher adsorption capacity towards glycoproteins than the nonclick-Fe 3O 4@APBA NPs which were synthesized through a common nucleophilic substitution reaction. The greatly enhanced adsorption capacity towards glycoproteins demonstrated that the 'click' method presented great superiority in ligand immobilization. Finally, the click-Fe 3O 4@APBA NPs could efficiently enrich glycoproteins from real egg white samples as well. © The Royal Society of Chemistry 2012.


Chen J.,Shandong Jiaotong University | Wang J.,CAS Shanghai Institute of Materia Medica | Zhu W.,CAS Shanghai Institute of Materia Medica | Li G.,CAS Dalian Institute of Chemical Physics
Journal of Computer-Aided Molecular Design | Year: 2013

Molecular dynamics (MD) simulations followed by principal component analysis were performed to study the conformational change of MDM2 induced by p53 and two inhibitor (P4 and MI63a) bindings. The results show that the hydrophobic cleft of MDM2 is very flexible and adaptive to different structural binding partners. The cleft tends to become wider and more stable as MDM2 binds to the three binding partners, while unbound MDM2 shows a narrower and pretty flexible cleft, which agrees with recent experimental data and theoretical studies. It was also found that the binding of P4 and p53 stabilizes the motion of the loop L2 linking the helix α2 and β strand (β3), but the presence of MI63a makes the motion of L2 disordered. In addition, the binding free energies of the three partners to MDM2 were calculated using molecular mechanics generalized Born surface area to explain the binding modes of these three partners to MDM2. This study will be helpful not only for better understanding the functional, concerted motion of MDM2, but also for the rational design of potent anticancer drugs targeting the p53-MDM2 interaction. © 2013 Springer Science+Business Media Dordrecht.


Chen D.,Liaoning Normal University | Yu S.,Liaoning Normal University | Liu X.,Liaoning Normal University | Li X.,CAS Dalian Institute of Chemical Physics
Journal of Power Sources | Year: 2015

Porous membranes based on polybenzimidazole (PBI) are firstly introduced in direct borohydride fuel cell application (DBFC). Membranes with different thicknesses and porosity are successfully fabricated via water vapor phase inversion process. The prepared membranes show excellent ion conductivity and chemical stability under DBFC operating condition. Compare with Nafion 115, the prepared membranes show higher ion conductivity, as a result, much higher peak power density. No weight loss is observed after immersing the prepared membranes in a 3 M NaOH solution for 30 days, indicating the excellent chemical stability of porous PBI membranes. And the DBFC cells assembled with prepared membranes could discharge at 200 mA cm-2 for more than 250 h without voltage decay, which is the longest time reported by far. This work provides a totally new idea for fabricating versatile DBFC membranes. © 2015 Elsevier B.V. All rights reserved.


Xu Y.,Nankai University | Wu M.,Nankai University | Liu Y.,Nankai University | Feng X.-Z.,Nankai University | And 4 more authors.
Chemistry - A European Journal | Year: 2013

Carbon dots (Cdots) are an important probe for imaging and sensing applications because of their fluorescence property, good biocompatibility, and low toxicity. However, complex procedures and strong acid treatment are often required and Cdots suffer from low photoluminescence (PL) emission. Herein, a facile and general strategy using carbonization of precursors and then extraction with solvents is proposed for the preparation of nitrogen-doped Cdots (N-Cdots) with 3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA), L-histidine, and L-arginine as precursor models. After they are heated, the precursors become carbonized. Nitrogen-doped Cdots are subsequently extracted into N,N′-dimethylformamide (DMF) from the carbogenic solid. A core-shell structure of Cdots with a carbon core and the oxygen-containing shell was observed. Nitrogen has different forms in N-Cdots and oxidized N-Cdots. The doped nitrogen and low oxidation level in N-Cdots improve their emission significantly. The N-Cdots show an emission with a nitrogen-content-dependent intensity and Cdot-size-dependent emission-peak wavelength. Imaging of HeLa cells, a human cervical cancer cell line, and HepG2 cells, a human hepatocellular liver carcinoma line, was observed with high resolution using N-Cdots as a probe and validates their use in imaging applications and their multicolor property in the living cell system. Going dotty: A facile and general strategy involving the carbonization of precursors and their subsequent extraction with solvents is proposed for the preparation of nitrogen-doped carbon dots (N-Cdots) with multicolor emission (see figure). The emission mechanism of the Cdots was studied. Multicolor photoluminescence was validated in living cell systems. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xu Y.,Nankai University | Wu M.,Nankai University | Feng X.-Z.,Nankai University | Yin X.-B.,Nankai University | And 3 more authors.
Chemistry - A European Journal | Year: 2013

The study of the composition, morphology, and surface structure of carbon dots (Cdots) is critical to understanding their effect on the photo- and electrochemiluminescence (PL and ECL) of Cdots in selected applications. Herein, two kinds of Cdots were prepared with 3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) as precursor. The Cdots prepared by using a carbonization-extraction strategy have a low oxidation level and are denoted as reduced Cdots (r-Cdots). The Cdots obtained with a carbonization-oxidation process are highly oxidized and are denoted as oxidized Cdots (o-Cdots). The o-Cdots have a carbon core and oxygen-containing loose shell, but the r-Cdots consist mainly of the carbon core. Whereas r-Cdots have a strong blue PL but no apparent ECL response, o-Cdots exhibit a relatively weak PL and strong ECL emission. These properties allow for selected applications of the Cdots. The r-Cdots were used in cell imaging with their high PL emission. The o-Cdots, with their high ECL efficiencies, were selected to sense Cu2+ with Cu2+- inducing ECL quenching in the o-Cdots/K2S2O8 system. This work provides the possibility to control the composition of Cdots for selected applications and shows a good way to characterize surface traps of Cdots because ECL is characterized by the surface-state and PL is mainly related to the core-state in Cdots. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xiao J.,Nanyang Technological University | Xiao J.,CAS Dalian Institute of Chemical Physics | Zhao K.,Nanyang Technological University | Loh T.-P.,Nanyang Technological University
Chemical Communications | Year: 2012

The acid free asymmetric intermolecular α-alkylation of aldehydes with alcohols has been discovered using trifluoroethanol as solvent. This unprecedented system affords the enantioenriched functionalized primary alcohols (after NaBH 4 reduction) in high yields and good to excellent enantioselectivities with wide substrate scope in the absence of any acid additive. © 2012 The Royal Society of Chemistry.


Liu Y.,Harbin Institute of Technology | Liu Y.,CAS Dalian Institute of Chemical Physics | Liu H.,Harbin Institute of Technology | Ma J.,Harbin Institute of Technology | Li J.,Harbin Institute of Technology
Electrochimica Acta | Year: 2011

The present work focused on the investigation of electrochemical properties of cerium doped lead dioxide anode, i.e. Ti/Ce-PbO2. SEM, AFM, XRD and XPS were used to characterize the morphology, crystal structure and elemental states of the modified anode. Electrochemical impedance spectroscopy (EIS) was also utilized to study the electrochemical property of Ti/Ce-PbO 2. The electrochemical activity of the Ti/Ce-PbO2 anode was investigated by means of bulk electrolysis and compared with that of a PbO2 anode. The accelerated life test and oxidants determination were also conducted. The results indicated that the incorporation of cerium improved the electrocatalytic activity and stability of PbO2 anode. The service life of Ti/Ce-PbO2 electrode was much longer than that of traditional lead dioxide electrode. The electrochemical activity obtained from degradation of o-nitrophenol (o-NP) outperformed the traditional lead dioxide electrode as well. The Ti/Ce-PbO2 electrode is considered a promising anode for the treatment of organic pollutants. © 2010 Elsevier Ltd. All rights reserved.


Ren X.-F.,Jilin University | Ren A.-M.,Jilin University | Feng J.-K.,Jilin University | Zhou X.,CAS Dalian Institute of Chemical Physics
Organic Electronics: physics, materials, applications | Year: 2010

Density functional theory (DFT) calculations have been carried out on the electronicstructures, electronic spectra, carrier injection and transport properties of a series ofporphyrin derivatives, 5,15-di(R)porphyrin, 5,10,15,20-tetra(R)porphyrin, and Zn-5,10,15,20-tetra(R)- porphyrin, namely, DCP, TCP, and ZCP (where R = carbazole); DMP, TMP, and ZMP (where R = N,N-dimethyl-phenyl); DQP, TQP, and ZQP (where R = 2,3,6,7-tetrahydro-1H, 5Hbenzo[ ij]puinolizine). The through-bond (TB) energy transfer process in these porphyrin derivatives has been verified by three aspects of characters, i.e. electronic structures, Dexter-type and Förster-type energy transfer. Moreover, the reasons for their high efficiency as red emitting materials have been revealed by the investigations of the ionization potential (IP), electron affinity (EA), reorganization energy (λ), and exciton binding energy (Eb). These structure-property relationships provide a valuable guide for the design and synthesis of highly efficient red light-emitting materials based on porphyrin derivatives. © 2010 Elsevier B.V.


Liu K.,Dalian Maritime University | Qin J.,CAS Dalian Institute of Chemical Physics
Nanotechnology | Year: 2013

A microfluidic device using droplet-fused microreactors is introduced for room temperature synthesis of nanoscale needle-shaped hydroxyapatite (HAp, Ca10 (PO4)6 (OH)2). The device is integrated with multifunctional units, e.g., T-junctions for droplet generation and fusion, winding channels for rapid mixing, and a delay line for simple visualization of the HAp formation process. The necessary conditions such as surfactant and fluid flow rate for an aqueous stream to merge with water-in-oil droplets are investigated. The nanoscale morphologies of the HAp produced by this method are also compared with HAp prepared by conventional bulk mixing. This paper shows that further reaction could be initiated by flowing additional reagent streams directly into the droplets of the initial reaction mixture, which is a novel approach for synthesizing a needle-like morphology of the HAp with a high aspect ratio under room temperature. © 2013 IOP Publishing Ltd.


Gai Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Zhang T.,Beijing Institute of Technology | Zhang Y.,CAS Dalian Institute of Chemical Physics
Talanta | Year: 2011

Both of the magnetic particle adsorption and aqueous two-phase extraction (ATPE) were simple, fast and low-cost method for protein separation. Selective proteins adsorption by carboxyl modified magnetic particles was investigated according to protein isoelectric point, solution pH and ionic strength. Aqueous two-phase system of PEG/sulphate exhibited selective separation and extraction for proteins before and after magnetic adsorption. The two combination ways, magnetic adsorption followed by ATPE and ATPE followed by magnetic adsorption, for the separation of proteins mixture of lysozyme, bovine serum albumin, trypsin, cytochrome C and myloglobin were discussed and compared. The way of magnetic adsorption followed by ATPE was also applied to human serum separation. © 2011 Elsevier B.V. All rights reserved.


Hong S.,Ewha Womans University | Pfaff F.F.,Humboldt University of Berlin | Kwon E.,Ewha Womans University | Wang Y.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2014

High-valent cobalt-oxo intermediates are proposed as reactive intermediates in a number of cobalt-complexmediated oxidation reactions. Herein we report the spectroscopic capture of low-spin (S = 1/2) CoIV-oxo species in the presence of redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, and the investigation of their reactivity in C-H bond activation and sulfoxidation reactions. Theoretical calculations predict that the binding of Lewis acidic metal ions to the cobaltoxo core increases the electrophilicity of the oxygen atom, resulting in the redox tautomerism of a highly unstable [(TAML)CoIII(O.)]2- species to a more stable [(TAML)CoIV(O)(Mn+)] core. The present report supports the proposed role of the redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.


Shao C.,Anhui University of Science and Technology | Yuan B.,Anhui University of Science and Technology | Wang H.,Anhui University of Science and Technology | Zhou Q.,Anhui University of Science and Technology | And 3 more authors.
Journal of Materials Chemistry | Year: 2011

Eggshell membrane (ESM) has been employed as a unique and especially efficient synthetic platform capable of generating fluorescent silver and gold nanoclusters via various chemical routes. Potential applications of the metal/ESM adducts include recyclable catalysts, sensing paper, surface enhanced Raman scattering interface, fluorescent surface patterning and anti-counterfeiting. © The Royal Society of Chemistry 2011.


Lei Y.,CAS Dalian Institute of Chemical Physics
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2010

A new method for isolation of gentiopicroside (GPS) from Swertia mussotii Franch with reversed phase preparative high performance liquid chromatography (Pre-HPLC) is described. After 95% ethanol extract was obtained with solvent extraction and macroporous resin separation, a fraction containing GPS was acquired and subjected to Pre-HPLC for isolation of target component. The optimum operation parameters were selected as follows: a C18 column (200 mm x 50 mm, 5 microm), methanol-0.1% acetic water (30:70, v/v) as the mobile phase at flow rate of 75 mL/min, the detection wavelength at 254 nm, and the injection volume of 500 microL at the mass concentration of 225 g/L. The purity of the product was detected by HPLC method. The result showed that the purity of product was above 99%. The effective and rapid method has been successfully applied to the preparation of GPS from Swertia mussotii Franch.


Yu L.,State Key Laboratory of Catalysis | Li W.-X.,State Key Laboratory of Catalysis | Li W.-X.,CAS Dalian Institute of Chemical Physics | Pan X.,State Key Laboratory of Catalysis | Bao X.,State Key Laboratory of Catalysis
Journal of Physical Chemistry C | Year: 2012

The interaction of an Fe atom, an Fe dimer, a one-dimensional Fe nanowire, and an FeO nanowire with a single-walled armchair carbon nanotube (CNT) (8, 8) is investigated using density functional theory calculations. The results show that for all iron species the bonding with the outside wall of the CNT is stronger than that with the inside wall. Analysis of the electron distribution of the CNT shows that the curvature of the CNT induces a significant electron disparity at the inside and outside regions and more electrons are distributed on the outer surface. The properties of the frontier orbitals of the CNT are studied, and the results show that the highest occupied molecular orbital and lowest unoccupied molecular orbital are mainly located outside the tube, which may account for the in- and out-dependent interactions of Fe species with the CNT surface and hence different chemical reactivities of CNT-loaded metals. © 2012 American Chemical Society.


Li G.,CAS Dalian Institute of Chemical Physics | Jin R.,Carnegie Mellon University
Catalysis Today | Year: 2016

Atomically precise bimetallic M x Au25-x(SR)18 (MCu and Ag, R=CH2CH2Ph) nanoclusters are investigated as oxide-supported catalysts for the catalytic oxidation of styrene. Their catalytic properties are compared with the case of homogold Au25(SR)18 nanocluster. The oxide-supported M x Au25-x(SR)18 catalysts give rise to 42-82% conversion of styrene at 70°C using (diacetoxyiodo)benzene (PhI(OAc)2) as the oxidant. The Ag and Cu dopants are found to modulate both the activity (i.e., conversion of styrene) and the selectivity to styrene epoxide or benzaldehyde (major products). The Ag x Au25-x(SR)18 clusters exhibit higher activity and benzaldehyde selectivity than the homogold cluster, while the Cu x Au25-x(SR)18 clusters primarily enhance the selectivity to benzaldehyde without significantly changing the activity. The results provide insights into the factors that influence the catalytic activity and selectivity in styrene oxidation. © 2015 Elsevier B.V.


Gao X.,Shandong University | Lu F.,Shandong University | Dong B.,CAS Dalian Institute of Chemical Physics | Zhou T.,Shandong University | And 2 more authors.
Chemical Communications | Year: 2014

Zwitterionic vesicles with AuCl4 - counterions were fabricated for the first time as the soft templates for colloidal synthesis of gold nanostructures; gold nanoplates spontaneously generated at the vesicle bilayers were observed and gold nanospheres were achieved via a stepwise reduction approach. © 2014 the Partner Organisations.


Wang P.,CAS Dalian Institute of Chemical Physics
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2011

Micro free flow electrophoresis (micro-FFE) is a continuous micro-separation or preparation technique, which has been applied in the analysis of biomolecules, such as cells, sub cell organics and proteins. In this review, the recent progresses in micro FFE are summarized, with emphasis on the design of microchips, the separation modes and the applications of micro-FFE. Furthermore, the further developments of micro-FFE are prospected.


Zhang M.,Nankai University | Wu Y.,Nankai University | Feng X.,Nankai University | He X.,Nankai University | And 3 more authors.
Journal of Materials Chemistry | Year: 2010

In this study, we report a simple method to coat mesoporous silica onto carbon nanotubes (CNTs) via a two-step procedure. Mesoporous CNTs@SiO 2 composites have been obtained by extracting cetyltrimethylammonium bromide (CTAB) via an ion-exchange procedure after silica-coated carbon nanotubes were synthesized with the aid of the cationic surfactant CTAB. The coating process was explicitly investigated, and a possible formation mechanism of the mesoporous CNTs@SiO2 was proposed, which reveals that the ratio of CTAB/CNTs plays a critical role in the coating process. Furthermore, the pore size of the as-prepared mesoporous silica could be exactly controlled by using different amounts of the bromide surfactant CTAB. The obtained mesoporous CNTs@SiO2 composite nanomaterial was evaluated with three typical proteins, cytochrome c (Cyt c), bovine serum albumin (BSA) and lysozyme (Lyz), with different molecular sizes. The adsorption and desorption of binary mixtures of Cyt c and BSA, Cyt c and Lyz, and a ternary mixture of Cyt c, BSA and Lyz showed that the mesoporous CNTs@SiO2 are effective and highly selective adsorbents for Cyt c. The as-prepared mesoporous CNTs@SiO2 composites have shown effective performance in size-selective adsorption of biomacromolecules, demonstrating great potential in biomacromolecular separation. © The Royal Society of Chemistry 2010.


Wu C.,CAS Dalian Institute of Chemical Physics | Cheng H.-M.,CAS Shenyang Institute of Metal Research
Journal of Materials Chemistry | Year: 2010

The development of hydrogen storage materials with high performance has been attracting considerable attention in recent years. Magnesium hydride, alanates, borohydrides and ammonia borane are the most promising candidates due to their high hydrogen capacity, but each type has its own shortcomings. In this short feature article, we highlight the current advances in the property enhancement of metal hydrides and complex hydrides by incorporating carbon materials, particularly carbon nanostructures such as nanotubes. Carbon with a small curvature radius exhibits prominent "catalytic" effect in conventional metal hydrides and complex hydrides. The smaller the curvature radius, the stronger the electronic affinity, and the stronger the interaction of carbon with hydrogen, which leads to a change of hydrogen release/combination energy, and consequently improving the de-/rehydrogenation kinetics. Meanwhile, the nanoconfinement effects of carbon scaffolds on all above hydrides were also discussed. © 2010 The Royal Society of Chemistry.


Zhang M.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | Zhang Y.,Nankai University | Zhang Y.,CAS Dalian Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2010

In this study, we report a method to synthesize core-satellite structured Fe3O4/polydopamine/Au composite nanoparticles (NPs). Firstly, the Fe3O4/polydopamine composite NPs with a well-defined core-shell structure are obtained using dopamine self-polymerization to form thin, surface-adherent polydopamine films onto the surface of a Fe3O4 "core". The polydopamine shell could be adjusted by controlling the experimental parameters such as reaction time and the reactant concentrations. Then, numerous "satellites" of gold nanoparticles were assembled on the surface of Fe3O4/polydopamine by reducing Au3+ between the Fe3O4/polydopamine solid and HAuCl4 solution. Next, 11-mercaptoundecanoic acid (11-MUA) forms a self-assembled monolayer of MUA on the surface of the Au NPs and polydopamine layer. Finally, IDA-Cu functionalized Fe3O4/polydopamine/Au composite NPs are obtained by the carboxyl groups of MUA reacting with iminodiacetic acid (IDA), charged with Cu2+. The IDA-Cu groups, acting as an "anchor", are attached on the gold and the polydopamine surface is designed for capturing target molecules. The morphology, structure and composition of the nanocomposites are characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectrometry (XPS). The resulting Fe3O4/polydopamine/Au composite NPs show not only a strong magnetic response to an externally applied magnetic field, but are also highly specific to protein bovine hemoglobin (BHb), and removal of abundant protein BHb in the bovine blood as well. This opens a novel route for future application in removing abundant protein in proteomic analysis. © 2010 The Royal Society of Chemistry.


He C.,Sun Yat Sen University | Liang Y.,Sun Yat Sen University | Fu R.,Sun Yat Sen University | Wu D.,Sun Yat Sen University | And 2 more authors.
Journal of Materials Chemistry | Year: 2011

A nanopores array in ordered mesoporous materials matters significantly to the reactant molecules arriving at the active catalytic sites in the interior of the nanostructure. However, how this effect works in the case of electrocatalysis needs investigating. We present that the nanopores array of carbon supports plays a significant role in determining Pt's accessibility and electroactivity. The ordered mesoporous carbons with interconnected pore channels (CMK-3) provide Pt nanoparticles with more than one order of magnitude superior Pt utilization efficiency and alcohol electrooxidation activity to those with isolated pore channels by carbon wall (FDU-15). This becomes more prominent in the case of the electrooxidation of isopropanol with a bigger molecular size and lower polarization. These findings indicate the significant role of nanoarchitectures in Pt's accessibility and electroactivity. It is possible to extend this concept to the other fine chemistry typical of surface activity and facile mass transport of molecules. © 2011 The Royal Society of Chemistry.


Li R.,CAS Dalian Institute of Chemical Physics
Methods in molecular biology (Clifton, N.J.) | Year: 2010

Fluorescently labeled carbon nanotube probes (CNTP) are prepared by derivatizing oxidized (o)-MWNTs with a fluorescein dye. Capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) detection is used to separate and detect CNTP in multidrug-resistant cells (K562A) and the parent cells (K562S). CE-LIF and flow cytometry investigation reveal that the CNTP can traverse the membranes in both cell lines without being pumped out by P-glycoprotein. The CE-LIF method is also useful for quantitative analysis of CNT in single cells, enabling drug delivery and multidrug resistance (MDR) studies. Moreover, toward quantifying the intracellular uptake of oxidized (o)-SWNTs with anchored Rhodamine123 (Rho123), fluorescence-quenching of Rho123 is measured by micellar electrokinetic chromatography coupled with LIF detection. Enhanced uptake of Rho123 in multidrug-resistant leukemia cells can be achieved with the aid of the o-SWNTs carriers. Besides being able to overcome MDR, o-SWNTs are shown to be excellent intracellular carriers possessing large adsorption capacity and prolonged release ability. Finally, it is demonstrated that o-SWNTs are safe for biological applications at concentrations of up to 40 microg/mL.


Nie S.,CAS Dalian Institute of Chemical Physics | Chu T.,Qingdao University
Journal of Theoretical and Computational Chemistry | Year: 2012

The vector correlations between products and reagents of the N( 2D) + D 2 reaction are investigated by employing quasi-classical trajectory (QCT) calculation on the accurate DMBE potential energy surface (PES) of the 2A″ state. Stereo-dynamic quantities, including the four generalized polarization-dependent differential cross-sections (PDDCSs), the angular distribution P(θ r), the dihedral-angle distribution P(φ r), as well as the product rotational angular distribution in the polar form of P(θ r, φ r), are calculated in the center-of-mass (CM) frame. The results indicate that the product rotational angular momentum j′ not only aligns along the y-axis, but also orients to the negative direction of the y-axis. The isotope effect in the context of chemical stereo-dynamics and influences of different versions of ground-state PESs on vector correlations are shown and discussed. © 2012 World Scientific Publishing Company.


Zhang W.,Nankai University | He X.-W.,Nankai University | Chen Y.,Nankai University | Li W.-Y.,Nankai University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2012

A new type of molecularly imprinted polymer (MIP)-based fluorescent artificial receptor was developed by anchoring MIP on the surface of denatured bovine serum albumin (dBSA) modified CdTe quantum dots (QDs) using the surface molecular imprinting process. The approach combined the merits of molecular imprinting technology and the fluorescent property of the CdTe QDs. The dBSA was used not only to modify the surface defects of the CdTe QDs, but also as assistant monomer to create effective recognition sites. Three different proteins, namely lysozyme (Lyz), cytochrome c (Cyt) and methylated bovine serum albumin (mBSA), were tested as the template molecules and then the receptors were synthesized by sol-gel reaction (imprinting process). The results of fluorescence and binding experiments demonstrated the recognition performance of the receptors toward the corresponding template. Under optimum conditions, the linear range for Lyz was from 1.4×10 -8 to 8.5×10 -6M, and the detection limit was 6.8nM. Moreover, the new artificial receptors were applied to separate and detect Lyz in real samples. This fluorescent artificial receptor may serve as a starting point in the design of highly effective synthetic fluorescent receptor for recognition of target protein. © 2011 Elsevier B.V..


Wang J.,CAS Dalian Institute of Chemical Physics
The Journal of chemical physics | Year: 2013

Systematic measurements were made on the deactivation rate constants (k(Δ)) of O(2)(a(1)Δ) by homologous series of gaseous n-alkanes and 1-alkenes by using our recently developed quasi-static method. The results indicate that the k(Δ) values for alkanes are in direct proportion to the number of C-H bonds (N(CH)) in the molecules, while those for alkenes are not, but being still linear with N(CH), which is in good agreement with Schmidt's E-V energy transfer model. The direct proportion and linearity relationship, respectively, for alkanes and alkenes were well explained in terms of the type and number of their C-H stretching vibrational modes, together with their corresponding vibrational constants. The physical mechanism for the linearity and additivity in Schmidt's model was also discussed in detail. In addition, the k(Δ) values for alkanes were found to be evidently smaller than those for alkenes with the same number of carbon atoms (n) for n < 4, while the situation is quite the contrary for n > 4, which was also rationalized in terms of E-V energy transfer mechanism, together with their respective C-H stretching vibrational modes.


Chen J.,Nanjing Southeast University | Lei W.,Nanjing Southeast University | Deng W.Q.,CAS Dalian Institute of Chemical Physics
Nanoscale | Year: 2011

An efficient photoelectrode is fabricated by sequentially assembling 2.5 nm and 3.5 nm CdSe quantum dots (QDs) onto a TiO2 film. As revealed by UV-vis absorption spectroscopy, two sizes of CdSe QD can be effectively adsorbed on the TiO2 film. With a broader light absorption range and better coverage of CdSe QDs on the TiO2 film, a power conversion efficiency of 1.26% has been achieved for the TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) cell under the illumination of one Sun (AM 1.5G, 100 mW cm-2). Electrochemical impedance spectroscopy shows that the electron lifetime for the device based on TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) is longer than that for devices based on TiO2/CdSe QD (2.5 nm) and TiO 2/CdSe QD (3.5 nm), indicating that the charge recombination at the interface is reduced by sensitizing with two kinds of CdSe QDs. © 2011 The Royal Society of Chemistry.


Feng L.-Q.,Liaoning University of Technology | Feng L.-Q.,CAS Dalian Institute of Chemical Physics | Liu H.,Liaoning University of Technology
Chinese Journal of Chemical Physics | Year: 2015

A promising method to improve the attosecond pulse intensity has been theoretically presented by properly adding an ultraviolet pulse into the orthogonal two-color field. The results show that by properly adding a 125 nm ultraviolet pulse to the orthogonal two-color field, not only the harmonic yield is enhanced by 2 orders of magnitude compared with the original orthogonal two-color field case, but also the single short quantum path, which is selected to contribute to the harmonic spectrum, results in an ultrabroad 152 eV bandwidth. Moreover, by optimizing the laser parameters, we find that the harmonic enhancement is not very sensitive to the pulse duration and the polarized angle of the assisted ultraviolet pulse, which is much better for experimental realization. As a result, an isolated pulse with duration of 38 as can be obtained, which is 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case. © 2015 Chinese Physical Society.


Li L.,Dalian University of Technology | Wang T.,Dalian University of Technology | Liu Q.,Dalian University of Technology | Cao Y.,CAS Dalian Institute of Chemical Physics | Qiu J.,Dalian University of Technology
Carbon | Year: 2012

Ordered mesoporous silica/carbon composite membranes with a high CO 2 permeability and selectivity were designed and prepared by incorporating SBA-15 or MCM-48 particles into polymeric precursors followed by heat treatment. The as-made composite membranes were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and N 2 adsorption, of which the gas separation performance in terms of gas permeability and selectivity were evaluated using the single gas (CO 2, N 2, CH 4) and gas mixtures (CO 2/N 2 and CO 2/CH 4, 50/50 mol.%). In comparison to the pure carbon membranes and microporous zeolite/C composite membranes, the as-made mesoporous silica/C composite membranes, and the MCM-48/C composite membrane in particular, exhibit an outstanding CO 2 gas permeability and selectivity for the separation of CO 2/CH 4 and CO 2/N 2 gas pairs owing to the smaller gas diffusive resistance through the membrane and additional gas permeation channels created by the incorporation of mesoporous silicas in carbon membrane matrix. The channel shape and dimension of mesoporous silicas are key parameters for governing the gas permeability of the as-made composite membranes. The gas separation mechanism and the functions of porous materials incorporated inside the composite membranes are addressed. © 2012 Elsevier Ltd. All rights reserved.


Zuo A.H.,CAS Dalian Institute of Chemical Physics
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica | Year: 2012

To analyze and identify the chemical constituents in rat brain tissues after oral administration of Chuanxiong Rhizoma extracts. The dosed and blank rat brain tissues were analyzed by UPLC-Q-TOF-MS. Different peaks were observed in total ion chromatograms and then identified according to their retention time, accurate mass weight, MS and MS/MS data. After oral administration of Chuanxiong Rhizoma extracts, 3 compounds were absorbed into rat brain tissues through BBB. They were identified as senkyunolide I, senkyunolide A and ligustilide. The study is helpful for interpreting effective substance of Ligusticum chuanxiong.


Tian Z.,Pacific Northwest National Laboratory | Tian Z.,CAS Dalian Institute of Chemical Physics | Tolic N.,Pacific Northwest National Laboratory | Zhao R.,Pacific Northwest National Laboratory | And 7 more authors.
Genome Biology | Year: 2012

Post-translational modifications (PTMs) of core histones work synergistically to fine tune chromatin structure and function, generating a so-called histone code that can be interpreted by a variety of chromatin interacting proteins. We report a novel online two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) platform for high-throughput and sensitive characterization of histone PTMs at the intact protein level. The platform enables unambiguous identification of 708 histone isoforms from a single 2D LC-MS/MS analysis of 7.5 μg purified core histones. The throughput and sensitivity of comprehensive histone modification characterization is dramatically improved compared with more traditional platforms. © 2012 Tian et al.; licensee BioMed Central Ltd.


Hao D.-C.,Dalian Jiaotong University | Yang L.,CAS Dalian Institute of Chemical Physics | Xiao P.-G.,Chinese Academy of Sciences | Liu M.,Dalian Jiaotong University
Physiologia Plantarum | Year: 2012

Plant microRNAs (miRNAs) have an impact in the regulation of several biological processes such as development, growth and metabolism by negatively controlling gene expression at the post-transcriptional level. However, the role of these small molecules in the medicinal gymnosperm species Taxus remained elusive. To elucidate the role of miRNAs in Taxus we used a deep sequencing approach to analyze the small RNA and degradome sequence tags of Taxus mairei leaves. For miRNAs, the sequencing library generated 14.9 million short sequences, resulting in 13.1 million clean reads. The library contains predominantly small RNAs with 21 nucleotide length, followed by 19-nt and 20-nt small RNAs. Around 29% of total small RNAs are matched to the T. mairei transcriptome. By sequence alignment, we identified 871 mature miRNAs, 15 miRNA* and 869 miRNA precursors representing known plant miRNA families. There are 547 unique small RNA matching the miRNA precursors. We predict 37 candidate novel miRNAs from the unannotated small RNAs that could be mapped to the reference transcriptome. The expression of the selected candidates was for the first time quantified by real-time reverse transcription polymerase chain reaction. The novel miRNA m0034 turns out to be from the intron sequence of the paclitaxel biosynthetic gene taxadiene synthase. The 21 potential targets of nine novel miRNAs are also predicted. Additionally, 56 targets for known miRNA families and 15 targets for novel candidate miRNA families were identified by high-throughput degradome-sequencing approach. It is found that two paclitaxel biosynthetic genes, taxane 13α hydroxylase and taxane 2α-O-benzoyltransferase, are the cleavage targets of miR164 and miR171, respectively. This study represents the first transcriptome-based analysis of miRNAs and degradome in gymnosperms. © Physiologia Plantarum 2012.


Feng L.,CAS Dalian Institute of Chemical Physics | Chu T.-S.,Qingdao University
IEEE Journal of Quantum Electronics | Year: 2012

We present an efficient method to enhance the attosecond pulse intensity when either a model He + ion or a neutral He atom is exposed to the combination of a synthesized two-color field (800 and 1600 nm) and a high-order harmonic pulse. The results show that, by properly adding an ultrashort 13th (61.5 nm), 27th (29.6 nm), or 6th (125.2 nm), 13th (62.6 nm) harmonic pulse (corresponding to an 800 nm pulse) to the synthesized two-color field, the harmonic yields from the \rm He + ion or the He atom are effectively enhanced by two to five or one to two orders of magnitude compared with the original two-color field case. Finally, by properly superposing the harmonic spectrum in the supercontinuum region, we can obtain an intense attosecond pulse as short as 41as (\rm He+) and 46as (He) from our 1-D simulations. © 1965-2012 IEEE.


Ren J.,CAS Dalian Institute of Chemical Physics | Ren J.,Nanyang Technological University | Li Z.,Nanyang Technological University
Desalination | Year: 2012

In this paper, the effects of γ-butyrolactone (GBL) weight ratio (w GBL) and membrane thickness on the formation of asymmetric flat sheet membranes prepared with P84 (BTDA-TDI/MDI co-polyimide)/N-methyl-2-pyrrolidone (NMP)/GBL casting solutions are investigated. With the increase of membrane thickness, the transition of membrane morphology from sponge-like to finger-like structure occurs at critical structure-transition thickness L c. L c and the general sponge-like structure thickness (L gs) increase with w GBL. For 20wt.% P84/NMP/GBL casting solution, the membrane morphology changes from finger-like to sponge-like structure at the critical weight ratio of GBL (w *=0.69). The membrane morphology and performance of hollow fibers spun with various w GBL are observed. Compared with the hollow fiber membranes made of 18wt.% P84/NMP/GBL dope solution with w GBL=0.75, the hollow fiber membranes spun with w GBL=0.25 present a higher permeation flux and a larger MWCO. As w GBL increases from 0.25 to 0.75, the membrane morphology transfers from finger-like to sponge-like structure. An increase in shear rate shifts the rejection curves towards left, and lowers the MWCO of hollow fiber membranes. For hollow fiber membranes spun with w GBL=0.75, a relatively high permeation flux and a large MWCO are obtained by the wet spinning process. © 2011 Elsevier B.V.


Xiao Z.,Dalian University of Technology | Jin S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Li W.,Michigan Technological University | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

The Cu-Fe catalysts with stoichiometric proportion (Cu/Fe molar ratio was 0.5) were prepared by an epoxide assisted route. The structural properties of Cu-Fe catalysts were determined by X-ray diffraction (XRD), and Mössbauer spectroscopy measurements. These results indicated that a crystalline phase transformation from c-CuFe 2O 4 to t-CuFe 2O 4 occurred when elevating the calcination temperature from 500 to 600 °C. The M-H plots exhibited that all Cu-Fe catalysts had ferromagnetic nature and the saturation magnetization values monotonously increased with increasing calcination temperature irrespective of the phases composition. The significant superparamagnetic behavior was observed in the results of magnetic and Mössbauer spectroscopy measurements. The H 2 temperature-programmed reduction (H 2-TPR) was also conducted for examining the reducibility of Cu-Fe catalysts. The catalytic performance of Cu-Fe catalysts was examined for the hydrogenolysis reaction of glycerol. It is found that the formation of spinel CuFe 2O 4 greatly enhances the hydrogenolysis activity. The highest glycerol conversion (47%) was obtained over CuFe-500 catalyst, while the selectivity of 1,2-propanediol was maintained at about 92% for all catalysts. © The Royal Society of Chemistry 2012.


Shi X.,Liaoning Normal University | Li J.,Liaoning Normal University | Tang Y.,Liaoning Normal University | Yang Q.,CAS Dalian Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2010

pH-Sensitive mesoporous zirconium diphosphonates have been successfully synthesized through the surfactant-assisted procedure using the organophosphonate derivative of piperazine, 1,4-bis(phosphomethyl)piperazine (BPMP), and ZrCl 4 as the metal precursor. The pH-sensitivity was derived from the reversible protonation-deprotonation of piperazine groups integrated in the mesoporous walls under different pH values, which endows mesoporous zirconium diphosphonates with reversible cationic-neutral surface properties. These pH-sensitive materials can effectively adsorb PDS (dinuclear cobalt phthalocyanine ammonium sulfonate, a photosensitizer of sulfonated phthalocyanine for photodynamic therapy of tumors) through strong electrostatic interaction. The PDS-loaded samples exhibit pH-dependent release behaviors for PDS in physiological buffer solutions as evidenced by the fact that almost no PDS release can be observed in simulated gastric fluid (pH 1.2) and a sustained release of PDS with a slower initial release rate was triggered with the electrostatic interaction disappearing due to the deprotonation of piperazine groups in the mesoporous walls under the weakly basic medium of simulated intestinal fluid (pH 7.5). The pH-sensitive mesoporous zirconium diphosphonates as smart carriers for pH-controllable release of anionic photosensitizer can be used to develop an oral colon-targeted drug delivery system in which the drug molecules will be trapped without release when passing through the stomach, and be released completely in a sustained-release method in the colon followed by a minimal drug release in the small intestine. © 2010 The Royal Society of Chemistry.


Meng L.,Polytechnic Institute of Porto | Meng L.,University of Minho | Li C.,CAS Dalian Institute of Chemical Physics
Nanoscience and Nanotechnology Letters | Year: 2011

Three different thickness dense TiO2 (150 nm, 300 nm and 450 nm respectively) films were deposited on ITO substrates by dc reactive magnetron sputtering technique. These dense TiO2 films were used as the blocking layers. After that, TiO2 nanorod films were deposited on these dense TiO2 films by same technique. Both the dense and nanorod TiO2 films have an anatase phase. The dense TiO2 films have an orientation along the [101] direction and the TiO2 nanorod films show a very strong orientation along the [110] direction. These TiO 2 materials were sensitized by N719 dye and the DSSCs were assembled using them as photoelectrode. The effect of the blocking layer on the efficiency of the DSSCs is discussed. The DSSC assembled using TiO2 nanorod film with 300 nm thickness blocking layer shows a high efficiency of 2.07%. Copyright © 2011 American Scientific Publishers.


Zhang M.,Nankai University | Cheng D.,Nankai University | He X.,Nankai University | Chen L.,Nankai University | And 2 more authors.
Chemistry - An Asian Journal | Year: 2010

Magnetic silica-coated magnetite (Fe3O4) sub-microspheres with immobilized metal-affinity ligands are prepared for protein adsorption. First, magnetite sub-microspheres were synthesized by a hydrothermal method. Then silica was coated on the surface of Fe 3O4 particles using a sol-gel method to obtain magnetic silica sub-microspheres with core-shell morphology. Next, the trichloro(4-chloromethylphenyl) silane was immobilized on them, reacted with iminodiacetic acid (IDA), and charged with Cu2+. The obtained magnetic silica sub-microspheres with immobilized Cu2+ were applied for the absorption of bovine hemoglobin (BHb) and the removal of BHb from bovine blood. The size, morphology, and magnetic properties of the resulting magnetic micro(nano) spheres were investigated by using scanning microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and a vibrating sample magnetometer (VSM). The measurements showed that the magnetic sub-microspheres are spherical in shape, very uniform in size with a core-shell, and are almost superparamagnetic. The saturation magnetization of silica-coated magnetite (Fe3O4) sub-microspheres reached about 33 emug-1. Protein adsorption results showed that the sub-microspheres had a high adsorption capacity for BHb (418.6 mgg-1), low nonspecific adsorption, and good removal of BHb from bovine blood. This opens a novel route for future applications in removing abundant proteins in proteo-mic analysis. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Gai Q.-Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Liu Z.-J.,Beijing Institute of Technology | Dai R.-J.,Beijing Institute of Technology | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Journal of Chromatography A | Year: 2010

Molecular imprinting as a promising and facile separation technique has received much attention because of their high selectivity for target molecules. In this study, the superparamagnetic lysozyme surface-imprinted polymer was prepared by a novel fabricating protocol, the grafting of the imprinted polymer on magnetic particles in aqueous media was done by atom transfer radical polymerization (ATRP), and the properties of the imprinted polymer were characterized in detail. Its high selective adsorption and recognition to lysozyme demonstrated the separation ability of the magnetic imprinted material to template molecule, and it has been used for quick and direct separation of lysozyme from the mixture of standard proteins and real egg white samples under an external magnetic field. Furthermore, the elution of lysozyme from the imprinted material was achieved by PEG/sulphate aqueous two-phase system, which caused lysozyme not only desorption from the imprinted materials but also redistribution in the top and bottom phase of aqueous two-phase system. The aqueous two-phase system exhibited some of the extraction and enrichment effect to desorbed lysozyme. Our results showed that ATRP is a promising method for the protein molecularly imprinted polymer preparation. © 2010 Elsevier B.V.


The application provides a catalyst for producing ethylene and propylene from methanol and/or dimethyl ether, and a preparation and application thereof. In the present application, a molecular sieve catalyst co-modified by rare earth metals and silanization is utilized. First, the material containing methanol and/or dimethyl ether reacts on the catalyst to generate hydrocarbons. The hydrocarbons are separated into a C


Patent
CAS Dalian Institute of Chemical Physics | Date: 2011-11-28

The present invention relates to a microcapsule preparation product of alginate-chitosan acyl derivatives, which is produced by mixing microcapsules of alginate-chitosan acyl derivatives with an aqueous solution, wherein the biomicrocapsule structureconsists of two parts, a microcapsule membrane and an inner core; the microcapsule membrane is a polyelectrolyte composite hydrogel membrane formed by chitosan, alginates and chitosan acyl derivatives, and the inner core is an alginate liquid or a hydrogel environment containing cells.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2012-07-24

The present invention relates to a method for producing cresol from phenol and methanol via gas phase alkylation, in which phenol and methanol are preheated and mixed with diluent gas, then the mixture continuously go through a catalyst bed comprising the catalyst for alkylation of phenol with methanol, to produce cresol by gas phase reaction at the reaction temperature of 200-500 C. and the weight hourly space velocity of 0.520 h


Patent
CAS Dalian Institute of Chemical Physics | Date: 2010-11-04

This invention provides methods for producing ethylene glycol from polyhydroxy compounds such as cellulose, starch, hemicellulose, glucose, sucrose, fructose, fructan, xylose and soluble xylooligosaccharides. The methods uses polyhydroxy compounds as the reactant, a composite catalyst having active components comprising one or more transition metals of Groups 8, 9, or 10, including iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium, and platinum, as well as tungsten oxide, tungsten sulfide, tungsten hydroxide, tungsten chloride, tungsten bronze oxide, tungsten acid, tungstate, metatungstate acid, metatungstate, paratungstate acid, paratungstate, peroxotungstic acid, pertungstate, heteropoly acid containing tungsten. Reacting at a temperature of 120-300 C. and a hydrogen pressure of 1-13 MPa under hydrothermal conditions to accomplish one-step catalytic conversion. It realizes efficient, highly selective, high yield preparation of ethylene glycol and propylene glycol from polyhydroxy compounds. The advantage of processes disclosed in this invention include renewable raw material and high atom economy. At the same time, compared with other technologies that converts biomass raw materials into polyols, methods disclosed herein enjoy advantages including simple reaction process, high yield of targeted products, as well as easy preparation and low cost for the catalysts.


The present invention provides a process for methanol coupled catalytic cracking reaction of naphtha using a modified ZSM-5 molecular sieve catalyst, comprising performing a co-feeding reaction of methanol and naphtha on the modified ZSM-5 molecular sieve catalyst to produce low carbon olefins and/or aromatic hydrocarbons. In the process, the modified ZSM-5 molecular sieve catalyst comprises, in term of weight percent, 25-80 wt % of a ZSM-5 molecular sieve, 15-70 wt % of a binder, and 2.2-6.0 wt % of lanthanum and 1.0-2.8 wt % of phosphorus loaded on the ZSM-5 molecular sieve. The naphtha comprises 63.8-89.5 wt % of saturated chain alkanes and 5.6-29.8 wt % of cyclic alkanes. The naphtha and methanol concurrently pass through the catalyst bed, which are reacted during contacting with the catalyst under a reaction condition of a reaction temperature of 550-670 C., a mass ratio of methanol to naphtha of 0.05-0.8, and a total mass space velocity of naphtha and methanol of 1.0-5 h


Patent
CAS Dalian Institute of Chemical Physics | Date: 2010-11-30

The present invention relates to a method for efficient conversion of carbohydrates into 5-hydroxymethylfurfural (HMF) in the presence of tantalum-containing solid acid, which shows good activity and high selectivity for HMF preparation from saccharides. The catalyst is stable in aqueous system which makes it as an ideal catalyst for HMF production. High HMF yield was obtained even in mild condition. The catalysts of the invention are advantageous in that they are environment-friendly, easy separation and recovery, can be re-used in subsequent reactions, do not corrode reaction reactors. These features make the catalyst as an ideal catalyst for HMF preparation and have strong industrial application significance.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2014-06-18

The present invention relates to catalysts and methods for efficient conversion of carbohydrates into 5-hydroxymethylfurfural (HMF), which shows good activity and high selectivity for HMF preparation from saccharides. The catalyst is stable in aqueous system which makes it as an ideal catalyst for HMF production. High HMF yield was obtained even in mild condition. The catalysts of the invention are advantageous in that they are environment-friendly, easy separation and recovery, can be re-used in subsequent reactions, do not corrode reaction reactors. These features make the catalyst as a suitable catalyst for HMF preparation and have strong industrial application significance.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2012-09-26

The present invention concerns a SAPO-34 molecular sieve and method for preparing the same, whose chemical composition in the anhydrous state is expressed as: mDIPA(Si


Patent
CAS Dalian Institute of Chemical Physics and Dalian Rongke Power Co. | Date: 2010-06-25

A polymer ion exchange membrane for acidic electrolyte flow battery. The membrane is nitrogen heterocycles aromatic polymer, especially polybenzimidazole type polymer. A nitrogen heterocycles in the membrane interact with acid in the electrolyte to form donor-receptor proton transport network, so as to keep the proton transport performance of the membrane. The preparation condition for the membrane is mild, and the process is simplicity. The preparation method is suitable for mass production. The membrane is used in acidic electrolyte flow battery, especially in vanadium flow energy storage battery. The membrane has excellent mechanical stability and thermostability. In vanadium redox flow battery, the membrane has excellent proton conduct performance and excellent resistance to the permeation of vanadium ions.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2014-03-27

A pseudo-esterase activity-based fluorescent probe for specific detection of albumin, which has a carboxylic ester bond that can be selectively cleaved by human serum albumin (HSA), therefore forming a hydrolysate, which has a fluorescence emission spectrum significantly different from that of the fluorescent probe. According to the fluorescence intensity of the fluorescent probe and hydrolysate, we can detect the content of HSA in a biological sample.


Disclosed are a type of catalyst which can catalyse the ring-addition reaction of CO