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Beijing Forestry University is a multi-disciplinary university under the administration of the Ministry of Education of the People's Republic of China. As one of the key national universities under the Ministry of Education, the university provides advanced education in the fields of forestry, Biological science, Biotechnology, ecology and environmental studies. It was one of the first universities to be admitted into the 211 Project and the 21st-century Educational Vitalization Action Program. Wikipedia.

Ma Y.-C.,Beijing Forestry University
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2012

Cholesterol oxidase is a bacterial FAD-dependent flavoprotein that efficiently oxidates steroidal 3/3-hydroxy group to catalyze the first step in cholesterol metabolism. Cholesterol oxidase is an enzyme with great commercial value and has been used in biocatalysis for producing a variety of steroids, as an insecticidal protein against the cotton boll weevil larvae in agriculture and, in particular, as a diagnostic enzyme for determining serun levels of cholesterol. These important applications promote the researchers to isolate the cholesterol oxidase producers, purify the enzyme and reveal the relationship between structure and function. This review focused on the recent progress about the microbial species of producing cholesterol oxidase, the type and structure, the catalytic mechanism and the application of cholesterol oxidase. The key of future research was prospected.

Wang Y.L.,Beijing Forestry University | Dentel S.K.,University of Delaware | Mahmudov R.,University of Delaware
Powder Technology | Year: 2011

Floccky tester is a typical torque rheometer used to study flocculants and flocculation characteristics of wastewater sludges. This study presents the variations in rheological, geometric characteristics of conditioned anaerobic digested sludge (ADS) to analyze the transformation between flocs and aggregates during a rotational test with a floccky rheometer. The results revealed that the network strength and resistance to shear reach their maximum values at the optimum dose of polymer zetag7557 on the basis of the area under torque-time curves of ADS. Large aggregates, even big sludge lumps, were observed as soon as the optimum polymer dose was injected into the ADS suspensions, and they continued to grow in average size as the shear duration was prolonged. Afterwards, these aggregates broke into smaller ones or were directly transformed into smaller and smaller flocs with the extension of shear application. The corresponding torque values in the torque-time curve showed similar behavior to the above variations. During the above process, the strongest network formed in conditioned ADS suspensions in which large aggregates were generated, while the ADS suspension with the largest single aggregate or the highest average size of aggregates/flocs did not assure the strongest network. The climax of fractal dimensions for conditioned ADS flocs were not coincident with that of the peak height in the torque-time curves for these ADS suspensions. © 2011 Elsevier B.V.

Wu T.,CAS Institute of Zoology | Hao S.,CAS Institute of Zoology | Sun O.J.,Beijing Forestry University | Kang L.,CAS Institute of Zoology
PLoS ONE | Year: 2012

Background: Global warming is characterized by not only an increase in the daily mean temperature, but also a diel asymmetric pattern. However, most of the current studies on climate change have only concerned with the mean values of the warming trend. Although many studies have been conducted concerning the responses of insects to climate change, studies that address the issue of diel asymmetric warming under field conditions are not found in the literature. Methodology/Principal Findings: We conducted a field climate manipulative experiment and investigated developmental and demographic responses to diel asymmetric warming in three grasshopper species (an early-season species Dasyhippus barbipes, a mid-season species Oedaleus asiaticus, and a late-season species Chorthippus fallax). It was found that warming generally advanced the development of eggs and nymphs, but had no apparent impacts on the hatching rate of eggs, the emergence rate of nymphs and the survival and fecundity of adults in all the three species. Nighttime warming was more effective in advancing egg development than the daytime warming. The emergence time of adults was differentially advanced by warming in the three species; it was advanced by 5.64 days in C. fallax, 3.55 days in O. asiaticus, and 1.96 days in D. barbipes. This phenological advancement was associated with increases in the effective GDDs accumulation. Conclusions/Significance: Results in this study indicate that the responses of the three grasshopper species to warming are influenced by several factors, including species traits, developmental stage, and the thermal sensitivity of the species. Moreover, species with diapausing eggs are less responsive to changes in temperature regimes, suggesting that development of diapausing eggs is a protective mechanism in early-season grasshopper for avoiding the risk of pre-winter hatching. Our results highlight the need to consider the complex relationships between climate change and specificity responses of invertebrates. © 2012 Wu et al.

Wang Y.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences | Lu Y.,CAS Research Center for Eco Environmental Sciences | Song C.,CAS Research Center for Eco Environmental Sciences | Luan Y.,Beijing Forestry University
Quaternary Research | Year: 2010

Soil organic carbon (SOC) is one of the key components for assessing soil quality. Meanwhile, the changes in the stocks SOC may have large potential impact on global climate. It is increasingly important to estimate the SOC stock precisely and to investigate its variability. In this study, Yangjuangou watershed was selected to investigate the SOC distribution under different land uses. We found that SOC concentration decreased with increasing soil depth under all land uses and was significantly different across the vertical soil profile (P < 0.01). However, considering effect of land use on SOC, it is only significant (P < 0.01) in the topsoil (0-5 cm) layer. This indicated that land use has a large effect on the stocks of SOC in the surface soil. The stratification ratio of SOC > 1.2 may mean that soil quality is improving. The order of the SOC density (0-30 cm) under different land uses is forestland > orchard land > grassland > immature forestland > terraced cropland. The SOC stock is found to be as large as 2.67 × 103 t (0-30 cm) in this watershed. Considering time effect of restoration, the slope cropland just abandoned is more efficient for SOC accumulation than trees planted in the semi-arid hilly loess area. © 2009 University of Washington.

Peng-le C.,Beijing Forestry University
Journal of Convergence Information Technology | Year: 2012

In view of the visual transformation of image after equipment shaking during the vision inspection which contributes to low inspection precision, a kind of high-precision vision inspection method based on the RANSAC algorithm is designed to stitch two images from different perspectives after shaking and finally improve precision of vision inspection image. Firstly extraction and matching of the feature points of two images is conducted, then RANSAC algorithm is used to carry on the estimation of transformation matrix, and finally image mosaic by Laplasse Pyramid principle is implemented. Experimental results show that this method has advantages of higher precision, better robustness and efficiency.

Guo Y.,South China University of Technology | Wang X.,South China University of Technology | Shu X.,South China University of Technology | Shen Z.,South China University of Technology | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

A series of amiphiphilic cellulose-based graft copolymers (MCC-g-PLA) with various molecular factors were synthesized in ionic liquid BmimCl and characterized by FT-IR, 1H NMR, 13C NMR, XRD, and TGA. Their solubility in a variety of solvents was compared. The prepared MCC-g-PLA copolymers can self-assemble into spherical nanomicelles (10-50 nm) in aqueous solution. The self-assembly behaviors of the MCC-g-PLA copolymers were systematically investigated by fluorescence probe. Furthermore, the hydrophobic antitumor drug paclitaxel (PTX) was successfully encapsulated into the MCC-g-PLA micelles. The drug encapsulation efficiency and loading content were found to be as high as 89.30% (w/w) and 4.97%, respectively. Results in this study not only suggest a promising cellulose-based antitumor drug carrier but also provide information for property-directed synthesis of the cellulose graft PLA copolymers. © 2012 American Chemical Society.

Wang C.X.,Beijing Forestry University
Applied Mechanics and Materials | Year: 2013

Low Impact Development (LID), with a core conception of maintaining urban hydrological recycle through source control, is an approach to land development that works with nature to manage stormwater as close to its source as possible. This paper summarized the concept, principle, development and research status of LID, analysed the LID approaches in High Point Community in the USA, aiming to forward experience of sustainable stormwater management. © (2013) Trans Tech Publications, Switzerland.

Xing Z.,Heilongjiang University | Sun D.,Beijing Forestry University | Yua X.,Heilongjiang University
Environmental Progress and Sustainable Energy | Year: 2010

The combined polyferric sulfate (PFS) coagulation with Fenton-like was investigated for treating nonde gradable antibiotic fermentation wastewater. The experimental results indicated that 62.2% of chemical oxygen demand (COD) and 66.7% of color were removed, under the optimum conditions ofcoagulant dosage 200 mg/L, stirring time 12 min, and settling time 1 h. From the PFS characterization by means of Fourier transform infrared, X-ray diffraction, scanning electron microscope, and transmission electron microscope, it was believed that PFS coagulation was a mechanism including adsorption, neutralization of charged particles, and bridging between colloid particles. In addition, optimal conditions of Fenton-like process were determined to be H 2O2 dosage of 150 mg/L and oxalic acid of 45 mg/L. With effluents of Fenton-like being controlled at pH 7.0, the pollutants could be coagulated further. The hydroxyl radicals measurement by means ofelectron paramagnetic resonance showed that Fenton-like system could produce more HO- than did photo-Fenton system. The total re moval efficiencies of COD and color could reach 935 and 96.7%, respectively. © 2009 American Institute of Chemical Engineers.

Wang Q.,Beijing Forestry University | Wang Q.,University of Oxford | Tang S.V.Y.,University of Nottingham | Lester E.,University of Nottingham | And 2 more authors.
Nanoscale | Year: 2013

We report a novel continuous-flow hydrothermal method for the synthesis of layered double hydroxide (LDH) nanoplates. The precursor solutions may be fed to the reactor so that the production of LDHs occurs in a continuous mode. By control of the synthesis temperature, pressure and contact time, the synthesis of LDH nanoplates can be tuned with constant and consistent product quality. This very general and simple approach shows high potential for commercial scale-up. © 2013 The Royal Society of Chemistry.

Shi X.,Beijing Forestry University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2015

Recently, the different electronic charges, which are related to the different coupling constants with magnetic field, in the two-component superconductor have been studied in the frame of Ginzburg-Landau theory. In order to study the electronic charges in detail we suggest the wave function in the two-component superconductor to be in the coherent state. We find the different electronic charges exist not only in the coherent state but also in the incoherent state. But the ratio of the different charges in the coherent state is different from the ratio in the incoherence. The expressions of the coupling constants are given directly based on the coherence effects. We also discuss the winding number in such a system. © 2015 Elsevier B.V. All rights reserved.

Song M.-H.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Song M.-H.,CAS Nanjing Institute of Soil Science | Yu F.-H.,Beijing Forestry University | Ouyang H.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | And 3 more authors.
Global Change Biology | Year: 2012

Plant species and functional groups in nitrogen (N) limited communities may coexist through strong eco-physiological niche differentiation, leading to idiosyncratic responses to multiple nutrition and disturbance regimes. Very little is known about how such responses depend on the availability of N in different chemical forms. Here we hypothesize that idiosyncratic year-to-year responses of plant functional groups to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing. We conducted a 6 year N addition experiment in an alpine meadow on the Tibetan Plateau released from grazing by livestock. The experimental design featured three N forms (ammonium, nitrate, and ammonium nitrate), crossed with three levels of N supply rates (0.375, 1.500 and 7.500 g N m -2 yr -1), with unfertilized treatments without and with light grazing as controls. All treatments showed increasing productivity and decreasing species richness after cessation of grazing and these responses were stronger at higher N rates. Although N forms did not affect aboveground biomass at community level, different functional groups did show different responses to N chemical form and supply rate and these responses varied from year to year. In support of our hypothesis, these idiosyncratic responses seemed to enable a substantial diversity and biomass of sedges, forbs, and legumes to still coexist with the increasingly productive grasses in the absence of grazing, at least at low and intermediate N availability regimes. This study provides direct field-based evidence in support of the hypothesis that idiosyncratic and annually varying responses to both N quantity and quality may be a key driver of community structure and species coexistence. This finding has important implications for the diversity and functioning of other ecosystems with spatial and temporal variation in available N quantity and quality as related to changing atmospheric N deposition, land-use, and climate-induced soil warming. © 2012 Blackwell Publishing Ltd.

Hou F.,Beijing Forestry University
Advanced Materials Research | Year: 2012

Supplier selection and evaluation is an important part of environmental purchase in green supply chains. How to determine suitable suppliers in the supply chain has become a key strategic consideration. Although there are many approaches having been put forward by researchers, however, considering the complex and unstructured nature of these decisions, the paper conducts an analysis on how to select desired suppliers by AHP, followed by a case study in an enterprise in China. © (2012) Trans Tech Publications.

Jiang X.,Beijing Forestry University | Gong P.,Swedish University of Agricultural Sciences | Bostedt G.,Swedish University of Agricultural Sciences | Xu J.,Peking University
Environment and Development Economics | Year: 2014

State-owned forest enterprises (SOFEs) in northeast China play important roles both in timber production and in the maintenance of ecological security. This paper examines the effects of a number of policy measures on the behavioral choices of the SOFEs. The results show that the extent to which SOFE supervising authorities emphasized the improvement of forest resources in their annual evaluation of the SOFEs had significant impacts on the harvest and investment decisions and the development of forest resources. Promotion of the management and utilization of non-timber resources, as well as reforms aiming to increase the efficiency of forest protection and management, reduced timber harvests and increased investment, which in turn led to improvements of forest resources, although the effects were small. In contrast, reforms aimed at timber harvest and afforestation activities actually contributed to increasing timber harvest, which affected the development of the forest resources negatively. © 2013 Cambridge University Press.

Tan H.-Y.,Beijing Forestry University | Li J.-Y.,Shandong Institute of Business and Technology
Procedia Engineering | Year: 2011

This paper indicates that Extenics theory can be used to solve the problem of mine safety. The method includes 4 steps: building the evaluation indexes system and matter-element model, determining the classical field and controlled field of the matter-element model of the coal mine safety comprehensive evaluation, determining the connection function of each index on every safety level and determining the evaluation grade. This paper builds up a coal mine safety comprehensive evaluation indexes system and a matter-element model of coal mine based on extension theory, and then illustrates.the model using a case of Bei-zao Mine and its data. © 2011 Published by Elsevier Ltd.

Liu H.-M.,South China University of Technology | Feng B.,South China University of Technology | Sun R.-C.,South China University of Technology | Sun R.-C.,Beijing Forestry University
Industrial and Engineering Chemistry Research | Year: 2011

Acid-chlorite pretreatment was developed to enhance bio-oil yield and decrease the optimum reaction temperature of cornstalk liquefaction in a stainless steel reactor (0.5 L) at temperatures of 200-340 °C. The effects of liquefaction temperature and ethanol amount on the bio-oil yield from liquefaction of cornstalk before and after pretreatment were investigated. The results showed that the pretreatment could markedly enhance the bio-oil yield and decrease the optimum temperature. The highest bio-oil yield (31.4%) was obtained from the liquefaction at the reaction temperature of 260 °C from the 1.5 h pretreated cornstalk. Unpretreated and pretreated cornstalks differed in chemical components, in which the acid-chlorite pretreatment increased carbohydrate content and removed some amount of lignin. Scanning electron microscopy showed that the pretreated cornstalks had extensive anomalous porosity and lamellar structures. X-ray analysis showed that this pretreatment process was unable to break apart inter- and intrachain hydrogen bonding in cellulose fibrils. GC/MS analysis showed that the pretreatment had an important effect on the formation of various compounds in the bio-oil. © 2011 American Chemical Society.

Liu S.,Beijing Forestry University
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

The near infrared spectra analysis model of the content of the acid soluble lignin and the model of the content of the Klason lignin were built by the iterative method separately at first. The results show that the prediction effect of the content of the Klason lignin is obviously better than that of the acid soluble lignin. Different from usual methods of building near infrared spectra analysis model, the approximate linear relation between the contents of the acid soluble lignin and the contents of the Klason lignin was used. Combined with the near infrared spectroscopy data of multi-wavelength, twenty sub models of prediction of the content of the acid soluble lignin were built with the help of the Klason lignin content whose prediction effect is better than that of the acid soluble lignin. By calculating the weighted mean value of the prediction values of these sub models, the new prediction value of the content of the acid soluble lignin of each acacia specimen was obtained at last. The prediction error of the new model is obviously less than that of the model built by the iterative method. It is possible that the method of modeling in the paper can be used to some chemical component contents when the predictions of them by usual methods are not very effective, and the effects of the near infrared spectra analysis of them will be improved.

Liu W.,Beijing Forestry University | Xu S.,Zhejiang University | Li Q.,Zhejiang University
Fatigue and Fracture of Engineering Materials and Structures | Year: 2013

As an engineered material, ultra-high toughness cementitious composite (UHTCC) exhibits the characteristics of pseudo strain hardening and multiple cracking under uniaxial tension. It can be applied as the reinforcing and protective material of concrete structures. In this paper, static and fatigue flexural tests were carried out on UHTCC-layered concrete composite beams, for which UHTCC layer was used on the tension side. Under both static and fatigue loads, plane section assumption was suitable for such composite beams, and a good bond strength was achieved between the two layers. For static specimens, the UHTCC layer enhanced the ductility of the concrete layer. While under cyclic loads, because of the reinforcing effect of UHTCC, more than one crack were formed in the concrete layer, which led to a ductile deformation. Furthermore, the fatigue damage process of the composite beam was analysed. © 2013 Wiley Publishing Ltd.

Cui B.-K.,Beijing Forestry University
Nordic Journal of Botany | Year: 2013

Two new polypores (Ceriporiopsis lavendula B. K. Cui sp. nov. and Skeletocutis inflata B. K. Cui sp. nov.) are described from the Guangdong Province in southern China. Ceriporiopsis lavendula is characterized by having resupinate basidiocarps with lavender to grayish blue pore surface and very thin to almost absent subiculum, a monomitic hyphal system with clamped generative hyphae, and oblong-ellipsoid to ellipsoid basidiospores. Moreover, it grows on wood of Castanopsis exclusively. Skeletocutis inflata is characterized by having pileate basidiocarps, smaller pores (8-10 per mm), inflated and partly dissolved skeletal hyphae in KOH. In addition, its tramal skeletal hyphae are parallel along the tubes. Identification keys to species of Ceriporiopsis and Skeletocutis occurring in China are provided. © 2013 The Authors.

Liu B.,South China University of Technology | Wang X.,South China University of Technology | Pang C.,South China University of Technology | Luo J.,South China Normal University | And 3 more authors.
Carbohydrate Polymers | Year: 2013

Microwave irradiation was used to intercalate quaternized carboxymethyl chitosan oligosaccharide (QCMCO) into the layer of rectorite (REC) to prepare QCMCO/REC (QCOR) nanocomposites in 70 min, which was much faster than conventional heating method of 48 h. The structures and morphology of QCOR nanocomposites were characterized by XRD, TEM, FT-IR and zeta potential analysis, the thermal behavior and antimicrobial activity of QCOR nanocomposites were also discussed. The results revealed that the interlayer distance of QCOR nanocomposites enlarged with the increase of QCMCO content, hydrogen bonding and electrostatic interaction between QCMCO and REC took place. As compared to QCMCO, the crystallinity of QCOR nanocomposites reduced, the thermal stability of QCOR nanocomposites improved, and the inhibitory activity of QCOR nanocomposites against microorganisms was stronger, the lowest minimum inhibition concentration was only 0.025% (w/v), the antimicrobial mechanism was discussed via TEM and SEM micrographs. © 2012 Elsevier Ltd.

Guo Y.,South China University of Technology | Wang X.,South China University of Technology | Shen Z.,South China University of Technology | Shu X.,South China University of Technology | And 2 more authors.
Carbohydrate Polymers | Year: 2013

Self-associating cellulose-graft-poly(ε-caprolactone) (cellulose-g-PCL) copolymers were successfully synthesized via homogeneous ring-opening polymerization (ROP) of ε-CL onto softwood dissolved pulp substrate in ionic liquid 1-N-butyl-3-methylimidazolium chloride ([Bmim]Cl). An organic catalyst N,N-dimethylamino-4-pyridine (DMAP) was compared with the traditional metal-based catalyst (Sn(Oct)2) as the catalyst of the reaction, and exhibited higher catalytic activity. By controlling the cellulose:ε-CL feed ratio and reaction temperature, the molecular architecture of the copolymers can be altered, as evidenced by FT-IR, 1H NMR, 13C NMR, TGA and XRD. The self-assembly behavior of the copolymers in water was investigated and characterized using fluorescence probe, dynamic light scattering (DLS) and SEM. The results showed that the cellulose-g-PCL copolymers could form nanosized micelles (approximately 20-100 nm) in water, and the micelle size and critical micelle concentration (CMC) can be controlled by varying the grafting ratio of PCL. These cellulose-based nanomicelles are expected to be useful in broad application fields. © 2012 Elsevier Ltd. All rights reserved.

Wu Z.-Y.,Beijing Forestry University | Song H.-T.,Beijing Institute of Technology
Computer Journal | Year: 2010

Ant-based routing protocols for mobile ad hoc networks (MANETs) have been widely explored, but most of them are essentially single-path routing methods that tend to impose a heavy burden on the hosts along the shortest path from source to destination. In this paper, we combine swarm intelligence and node-disjoint multipath routing to alleviate these problems. A novel approach called ant-based energy-aware disjoint multipath routing algorithm (AEADMRA) is proposed. AEADMRA is based on swarm intelligence and especially on the ant colony-based meta heuristic. AEADMRA can discover multiple energy-aware node-disjoint routing paths with a low routing overhead. Simulation results indicate that the performance of AEADMRA outperforms other pertinent algorithms.

Que Z.-L.,Nanjing Forestry University | Que Z.-L.,Kyoto University | Wang F.-B.,Nanjing Forestry University | Li J.-Z.,Beijing Forestry University | Furuno T.,The University of Shimane
Composites Part B: Engineering | Year: 2013

This paper assesses the reproducibility of testing formaldehyde and VOCs (volatile organic compounds) emissions from wood-based composites such as MDF (medium density fiberboard), hardboard, plywood, coated and raw particleboards, planed pine lumber, and gypsum board. Sawdust and shavings were also included in the study. With the help of a special device, air was sucked from the surfaces of the materials and then was adsorbed on charcoal and Tenax tubes. The adsorbed VOCs were determined by gas chromatography/mass spectrometry. The emission of formaldehyde was determined separately with Interscan Toxic Gas analyzer and chamber method. The results showed that the most emitted VOCs were terpenes, aldehydes, and aromatics. Pine wood plank revealed the highest VOCs (approximately 900 μg/m3). Fresh particleboard showed the second highest value with 450 μg/m3. The VOC value of other examined materials were 80-170 μg/m3. The composition of the emitted compounds was remarkably similar among the different materials. The low VOC emission from the board materials investigated did not verify the hypothesis that these materials provided a tangible contribution to VOCs in the indoor air. Emission of formaldehyde from the board materials studied was very low with an exception. The exception was MDF with an emission value of 0.63 mg/m3 formaldehyde whereas all the other materials examined had values around 0.05 mg/m3 or appreciably lower. © 2013 Elsevier Ltd. All rights reserved.

Cui B.-K.,Beijing Forestry University
Mycological Progress | Year: 2013

Antrodia tropica sp. nov. is described and illustrated on the basis of collections originating from Hainan, southern tropical China. Both the morphology and phylogenetic analysis of rDNA ITS sequences support this new species. Morphologically, it is characterized by resupinate basidiocarps, an annual growth habit, greyish to pinkish buff pore surface, a dimitic hyphal system with clamped generative hyphae, and cylindrical to subfusiform basidiospores. The hymenophoral trama is dominated by generative hyphae, whereas skeletal hyphae are dominant in the subiculum. Molecular phylogeny inferred from ITS sequence data suggested a close relationship between A. tropica and two other Antrodia species, including A. huangshanensis reported from China and A. ramentacea found mostly in boreal Eurasia. © 2012 German Mycological Society and Springer.

Zhang G.-F.,Beijing Forestry University
Proceedings of the ACM Symposium on Applied Computing | Year: 2011

This paper presents a method based on connectivity analysis of graph to solve structurally under-constrained constraint problems frequently occurred during design process in parametric CAD. We give a partial solution to the optimal well-constrained completion problem, that is, adding automatically new constraints to the graph corresponding to an under-constrained geometric constraint problem G in such a way that G is well-constrained and the set of equations needed to be solved simultaneously in order to solve G has the smallest size. With this method, a connected, bi-connected, or tri-connected structurally under-constrained problem in 2D can be transformed into a structurally well-constrained one by adding new constraints automatically during the process of decomposing it into a decomposition tree. © 2011 ACM.

Zheng J.,Beijing Forestry University | Martinez-Cabrera H.I.,University of Quebec at Montreal
Annals of Botany | Year: 2013

Background and AimsIn recent years considerable effort has focused on linking wood anatomy and key ecological traits. Studies analysing large databases have described how these ecological traits vary as a function of wood anatomical traits related to conduction and support, but have not considered how these functions interact with cells involved in storage of water and carbohydrates (i.e. parenchyma cells).MethodsWe analyzed, in a phylogenetic context, the functional relationship between cell types performing each of the three xylem functions (conduction, support and storage) and wood density and theoretical conductivity using a sample of approx. 800 tree species from China.Key ResultsAxial parenchyma and rays had distinct evolutionary correlation patterns. An evolutionary link was found between high conduction capacity and larger amounts of axial parenchyma that is probably related to water storage capacity and embolism repair, while larger amounts of ray tissue have evolved with increased mechanical support and reduced hydraulic capacity. In a phylogenetic principal component analysis this association of axial parenchyma with increased conduction capacity and rays with wood density represented orthogonal axes of variation. In multivariate space, however, the proportion of rays might be positively associated with conductance and negatively with wood density, indicating flexibility in these axes in species with wide rays.ConclusionsThe findings suggest that parenchyma types may differ in function. The functional axes represented by different cell types were conserved across lineages, suggesting a significant role in the ecological strategies of the angiosperms. © The Author 2013.

Ma M.-G.,University of Konstanz | Ma M.-G.,Beijing Forestry University | Colfen H.,University of Konstanz
Current Opinion in Colloid and Interface Science | Year: 2014

Mesocrystals are superstructures of nanoparticles with mutual order and can be intermediates in a non-classical particle-mediated crystallization reaction. Mesocrystals have various potential applications as functional materials due to their unique combination of nanoparticle properties and order combined with a microscopic or even macroscopic size. They can also show collective and emergent properties. In the past, most attention has been paid to the synthesis and the formation mechanism of mesocrystals and in some cases properties and potential applications were reported. Only recently, the number of studies on mesocrystal applications has increased with a clear focus on photocatalysis, Li-ion battery and electrode applications. In this opinion paper, the remarkable progress in the field of mesocrystal applications of the last three years is highlighted including examples, where mesocrystals already now can by far outperform traditional materials with their excellent material properties, which can even reach the theoretically maximally possible value. The future application potential of mesocrystals is also discussed. © 2014 Elsevier Ltd.

Wei Y.,University of Science and Technology of China | Du J.,Beijing Forestry University | Chen R.,University of Science and Technology of China
Intermetallics | Year: 2016

The effects of Co alloying on mechanical properties of ternary Cu-Zr-Al bulk metallic glass (BMG) are systematically examined. Room temperature compression tests reveal enhanced fracture strain in ZrCuAlCo BMG materials upon appropriate amount of Co alloying. The microstructures of the composite materials investigated by X-ray diffraction and transmission electron microscopy reveal that the enhancement of fracture strain depends on the size and volume fraction of the B2 phase. The stress induced martensite transformation can only occur when the size of B2 grains is larger than a critical value, which enhances crack resistance within the vicinity of crack tip. © 2015 Elsevier Ltd. All rights reserved.

Wang M.,Capital Normal University | Qi S.,Shandong Normal University | Zhang X.,Beijing Forestry University
Environmental Earth Sciences | Year: 2012

Environmental degradation of wetlands is a major issue in the Yellow River Delta of China. Natural threats and human activities, such as flow cut-off of the Yellow River and droughts, population growth and urbanization, cause wetlands degradation of the delta during the last century, especially in the recent 50 years. Wetland degradation in the Yellow River Delta was investigated and its causation was analyzed. The results indicated that landscape changes of wetlands were mostly tremendous in the whole delta, namely loss of wetland area, surface water and groundwater pollution. Some new degradation control measures based on traditional and scientific knowledge must be used to reverse the wetlands degradation in the Yellow River Delta. © 2011 Springer-Verlag.

Huang H.-G.,Beijing Forestry University
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2013

The research progress of LiDAR technology on forestry science studies was comprehensively discovered using literature analysis based on the Web of science platform. One thousand and 355 related papers since year 2000 were found and used for statistics, including year trend, regional distribution, author ranking, journal distribution, institution of authors, and major forest parameters. The principal international and internal conferences on forestry LiDAR applications were also summarized. The main types of LiDAR sensors were classified; and two data structures were proposed (waveform and point cloud). The methods to extract forest parameters from LiDAR were systematically analyzed, including waveform analysis, point cloud analysis, forest parameter prediction and data fusion. We conclude that the depth and breadth of LiDAR application studies over forestry science are keeping increasing; research methods are becoming a system; there are systematic international conferences; but research level varies with region; mechanism and practicability to extract forest parameters are inadequate from maturity, which leaves room for improvements. Finally, suggestions on theory, application and organization studies on LiDAR applications on forestry were proposed to provide a kind of reference for related researchers and workers.

Yu X.,Beijing Forestry University
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering | Year: 2013

After a brief review on eco-hydrology history in past decades, an overview was made about the latest research progress of the eco-hydrology development, ecosystems, and eco-hydrological models. Based on the problems that eco-hydrological processes were not systematic, the scale of hydrological processes was limited, the study of the hydrological model was still immature and so on, we putted forward many suggestions: Strengthen the multidisciplinary and comprehensive study, the hydrological processes and scale study, the eco-hydrology and climate change study; and also pointed out the future direction of development: pay more attention to the restoration eco-hydrology, the study eco-hydrology and water environment, the eco-hydrological and ecological water, eco-hydrology and high-tech combination.

Xu D.,Beijing Forestry University
Wood and Fiber Science | Year: 2012

Nitrogen-enriched activated carbons were prepared from wood fiberboard waste using 50% potassium hydroxide solution. Activated carbons were obtained with an impregnation ratio (gram chemical agent/gram wood fiberboard waste) of 3 in 850°C activation temperature carbonized for 60 min. Nitrogen content in activated carbon was 1.33% by analysis. Effects of contact time, pH, adsorbent dosage level, and temperature on phenol adsorption capacity of activated carbons were investigated. Adsorption equilibrium was achieved within 100 min at the given phenol concentration of 250 mg/L. When 0.1 g of the carbon absorbent and 100 mL of phenol solution at 250 mg/L were used, maximum adsorption capacity of phenol on activated carbon can reach 207 mg/g. The kinetics of phenol adsorption followed nicely the pseudo-second-order rate expression. In the adsorption isotherm, the Langmuir model fit better than the Freundlich model in phenol adsorption. This study suggests that nitrogen-enriched activated carbon prepared from wood fiberboard waste can be used effectively for removal of phenol compounds from aqueous solutions. © 2012 by the Society of Wood Science and Technology.

Ji X.,Beijing Forestry University | Song Y.,Dalian University of Technology
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011

The bond between plain steel bar and concrete mainly includes gumming force and bond friction on the interface, the bond behavior can be weakened or destroyed after freezing and thawing. The bond behavior between steel bar and concrete after freezing and thawing was studied. The bond degradation was discussed based on analyzing the experimental data. Based on the theory of hydraulic pressure and bond friction, the mechanism of bond degradation after freeze-thaw cycling was investigated. The results show that the hydraulic pressure maximal value on the interface between concrete and steel bar after freezing and thawing is larger than the cross section adhesion, which is the main reason of bond strength decreasing.

Zhou J.-Z.,Beijing Forestry University
Xi'an Jianzhu Keji Daxue Xuebao/Journal of Xi'an University of Architecture and Technology | Year: 2011

Firstly, the wind-resistance effect test was carried out with one P. bolleana in this article, and a conclusion was arrived at that P. bolleana was obviously effective to reduce wind speed and wind pressure. And then through dynamic loading test of five P. bolleana under laboratory condition simulating natural wind power, the characteristic curves of wind-induced dynamic displacement and wind-induced dynamic strain were acquired. In the dynamic loading test of four P. bolleana under the condition of true wind power outdoors, characteristics curves of wind-induced dynamic strain, wind-induced dynamic displacement, wind-induced dynamic speed and wind-induced dynamic acceleration response were also obtained. Finally, a comparison was carried out on the dynamic response characteristic curves of P. bolleana under both indoor and field test conditions. Test and analysis showed that displacement, velocity and acceleration had obvious pertinence on the upper and lower measuring point position in the same direction of stem of P. bolleana, and in the random wind load excitation, the forest fibers of outer surface were in alternating tension-compression state, and with the increase in forest height, wind-induced dynamic displacement of forest was larger. This article has the important theorelical significance and practical value to wind resistance, disaster alleviation and protection of forest.

Jiang Y.,Beijing Forestry University
International Journal of Continuing Engineering Education and Life-Long Learning | Year: 2012

There have been many attempts to explore the reasons of Chinese student's reticence in classroom learning. Interestingly, the years of discussion about the beneficial features of computer mediated communication (CMC) seems able to convince us of the possibility in developing learner interaction via CMC. After a comparison between CMC and a traditional Chinese classroom, this article presents a case study aiming to examine how the seemingly perfect tool - CMC - improves interaction in a Chinese ESL context. This article firstly provides a glimpse of some interpretations of Chinese students' reticent behaviour. Next, it explains why CMC may possibly help in developing interaction in the Chinese EFL context with the diverse features of CMC related. After that, the Chinese students' interaction on a bulletin board system is analysed and the reasons behind reticence are articulated. Copyright © 2012 Inderscience Enterprises Ltd.

Yang J.,Beijing Forestry University | Zhao J.,Beijing SL Pharmaceutical Co.
Materials Letters | Year: 2014

Nanocomposite hydrogels consisting of inorganic (silica nanoparticles, SNPs)/organic (poly(acrylic acid), PAA) network structures are synthesized by in situ free polymerization from SNP surface in an acrylic acid (AA) aqueous solution. The effects of composition, including concentrations of SNP (C SNP) and AA (CAA), on hydrogels reinforcement behaviors are investigated, and the results reveal that the mechanical properties of the network are markedly influenced by CSNP as well as CAA. In contrast to chemical gels that cross-linked by N,N'-methylene-bisacrylamide (BIS), the SNP-PAA gels show excellent tensile properties, with elongation at break up to 900% and tensile strength greater than 300 kPa. All these results are consistent with the proposed cross-linked network structures for SNP-PAA gels. © 2014 Elsevier B.V.

Wu C.,Michigan State University | Li S.,St Jude Childrens Research Hospital | Cui Y.,Michigan State University | Cui Y.,Beijing Forestry University
Current Genomics | Year: 2012

The availability of high-density single nucleotide polymorphisms (SNPs) data has made the human genetic association studies possible to identify common and rare variants underlying complex diseases in a genome-wide scale. A handful of novel genetic variants have been identified, which gives much hope and prospects for the future of genetic association studies. In this process, statistical and computational methods play key roles, among which information-based association tests have gained large popularity. This paper is intended to give a comprehensive review of the current literature in genetic association analysis casted in the framework of information theory. We focus our review on the following topics: (1) information theoretic approaches in genetic linkage and association studies; (2) entropy-based strategies for optimal SNP subset selection; and (3) the usage of theoretic information criteria in gene clustering and gene regulatory network construction. © 2012 Bentham Science Publishers.

Yellow horn (Xanthoceras sorbifolia Bunge) is an oil-rich seed shrub that grows well in cold, barren environments and has great potential for biodiesel production in China. However, the limited genetic data means that little information about the key genes involved in oil biosynthesis is available, which limits further improvement of this species. In this study, we describe sequencing and de novo transcriptome assembly to produce the first comprehensive and integrated genomic resource for yellow horn and identify the pathways and key genes related to oil accumulation. In addition, potential molecular markers were identified and compiled. Total RNA was isolated from 30 plants from two regions, including buds, leaves, flowers and seeds. Equal quantities of RNA from these tissues were pooled to construct a cDNA library for 454 pyrosequencing. A total of 1,147,624 high-quality reads with total and average lengths of 530.6 Mb and 462 bp, respectively, were generated. These reads were assembled into 51,867 unigenes, corresponding to a total of 36.1 Mb with a mean length, N50 and median of 696, 928 and 570 bp, respectively. Of the unigenes, 17,541 (33.82%) were unmatched in any public protein databases. We identified 281 unigenes that may be involved in de novo fatty acid (FA) and triacylglycerol (TAG) biosynthesis and metabolism. Furthermore, 6,707 SSRs, 16,925 SNPs and 6,201 InDels with high-confidence were also identified in this study. This transcriptome represents a new functional genomics resource and a foundation for further studies on the metabolic engineering of yellow horn to increase oil content and modify oil composition. The potential molecular markers identified in this study provide a basis for polymorphism analysis of Xanthoceras, and even Sapindaceae; they will also accelerate the process of breeding new varieties with better agronomic characteristics.

Su Z.,Pennsylvania State University | Ma X.,Pennsylvania State University | Guo H.,Pennsylvania State University | Guo H.,Beijing Forestry University | And 6 more authors.
Plant Cell | Year: 2013

Drought dramatically affects plant growth and crop yield, but previous studies primarily examined responses to drought during vegetative development. Here, to study responses to drought during reproductive development, we grew Arabidopsis thaliana plants with limited water, under conditions that allowed the plants to initiate and complete reproduction. Drought treatment from just after the onset of flowering to seedmaturation caused an early arrest of floral development and sterility. After acclimation, plants showed reduced fertility that persisted throughout reproductive development. Floral defects included abnormal anther development, lower pollen viability, reduced filament elongation, ovule abortion, and failure of flowers to open. Drought also caused differential expression of 4153 genes, including flowering time genes FLOWERING LOCUS T, SUPPRESSOR OF OVEREXPRESSION OF CO1, and LEAFY, genes regulating anther and pistil development, and stress-related transcription factors. Mutant phenotypes of hypersensitivity to drought and fewer differentially expressed genes suggest that DEHYDRATION RESPONSE ELEMENT B1A may have an important function in drought response in flowers. A more severe filament elongation defect under drought in myb21 plants demonstrated that appropriate stamen development requires MYB DOMAIN PROTEIN 21 under drought conditions. Our study reveals a regulatory cascade in reproductive responses and acclimation under drought. © 2013 American Society of Plant Biologists. All rights reserved.

Tan Y.-S.,Beijing Forestry University
Advanced Materials Research | Year: 2011

Aiming at kinematic accuracy and its' error sources of a free floating space robot, a mathematical kinematic error model based on the concept of virtual manipulator and screw theory is proposed in this paper for a free-floating space robot. Based on screw theory, structural parameters in the form of motion screw and their error expressions derived from various error sources are deduced. The effect of mass error, CM (Center of Mass) error and structural parameter error on the kinematic accuracy of the free-floating space manipulator is analyzed. A simulation is demonstrated for verifying the correctness of the kinematic error model and the effect of various error sources on the free-floating space robot. The error model and the result deriving from analyzing are vital for studying the kinematic accuracy of the space manipulator when it is under a free-floating mode, and for controlling and assigning various errors when a space robot is developed. © (2011) Trans Tech Publications.

Yang F.,Northwest University, China | Yang F.,University of Nebraska - Lincoln | Hanna M.A.,University of Nebraska - Lincoln | Sun R.,Beijing Forestry University
Biotechnology for Biofuels | Year: 2012

Biodiesel is a promising alternative, and renewable, fuel. As its production increases, so does production of the principle co-product, crude glycerol. The effective utilization of crude glycerol will contribute to the viability of biodiesel. In this review, composition and quality factors of crude glycerol are discussed. The value-added utilization opportunities of crude glycerol are reviewed. The majority of crude glycerol is used as feedstock for production of other value-added chemicals, followed by animal feeds. © 2012 Yang et al; licensee BioMed Central Ltd.

Wu Z.,Hunan University | Zhang P.,Hunan University | Zhang P.,Beijing Forestry University | Zeng G.,Hunan University | And 2 more authors.
Journal of Environmental Engineering (United States) | Year: 2012

Humic acid (HA) removal from water with inorganic polyaluminum coagulants is reported in this paper. Polyaluminum chloride (PAC) and three kinds of polyaluminum chloride sulfate (PACS) with a [SO42-]/[Al3+] (S) molar ratio of 0.02, 0.06, and 0.10 were prepared. The coagulation behaviors of these coagulants were investigated in the view of coagulant dosage, initial pH, and aging time. PACS (S=0.06) showed the best HA removal efficiency, and there was no restabilization within a broad effective dosage range. The proper initial pH range was broad and was 4.0-9.0 for PACS (S=0.06). The stability of PACS (S=0.06) reduced with a long aging time, so the proper aging time should not exceed 1 month. The aluminum species distribution, particle mean size, charge neutralization, and infrared spectrum of prepared coagulants were tested. Results showed that SO42-addition promoted the hydrolysis/polymerization of aluminum and reduced the charge neutralization capacity of PACS. Besides charge neutralization, the bridge-aggregation and sweep-flocculation mechanisms may play important roles for HA removal. The coexisting Ca2+ and kaolin slightly promoted the HA removal with polyaluminum coagulants. © 2012 American Society of Civil Engineers.

Liu J.L.,Beijing Forestry University | Wang Y.G.,Chinese Academy of Forestry | Yang X.H.,Chinese Academy of Forestry | Wang B.F.,Chinese Academy of Forestry
Agroforestry Systems | Year: 2011

China is one of the countries most severely affected by desertification. Haloxylon ammodendron is an ecologically important component of the desert ecosystem and is one of the main shrub species used for ecological restoration. We compared the genetic variation in seed and seedling traits among six H. ammodendron provenances arrayed from east to west in China. The experiment was carried out in a greenhouse in well-prepared seedling beds (lines 1.5 m apart and seeds with in lines 1.0 m apart, 2.0 cm deep) with five lines (seven seeds per line) per provenance in a randomized block design with six replicates. The seed traits of fruit wing length, kernel weight, germination rate, and survival rate were compared, as were the seedling traits of internode length, branch number, assimilation shoot diameter, height, collar diameter, new shoot length, main root number, main root length, aboveground fresh weight, and underground fresh weight. Moreover, correlations between each seed and seedling trait and climate and geographical factors were assessed. The results show that the seeds from Dengkou County, Inner Mongolia had the best performance. Germination rate and survival rate were significantly positively correlated with longitude; and fruit wing length, kernel weight, seedling height, and new shoot length were significantly negatively correlated with latitude. Fruit wing length was significantly correlated with altitude. Among the climatic factors, the temperature in January had a strong direct effect on fruit wing length, germination rate, seedling height, and new shoot length. The mean annual rainfall had a strong direct effect on collar diameter. Humidity had a strong direct effect on survival rate. Seedling height, aboveground weight, and collar diameter could be important criteria for early provenance selection in the seedling stage. This study provides a reference for the selection of high-quality H. ammodendron seeds for drylands of northwest China. © 2010 Springer Science+Business Media B.V.

Miao C.Y.,Beijing Normal University | Yang L.,CAS Institute of Geographical Sciences and Natural Resources Research | Chen X.H.,University of Nebraska - Lincoln | Gao Y.,Beijing Forestry University
Land Degradation and Development | Year: 2012

Vegetation significantly influences human health in the Yellow River basin and the plant cover is vulnerable to people. Typical types of erosion in the Yellow River basin include that caused by water, wind and freeze-thaw. In this paper, vegetation cover change from 1982 to 2006 was studied for a number of different erosion regions. The Global Inventory Monitoring and Modeling Studies Normalized Difference Vegetation Index (GIMMS NDVI) data were employed, while climatic data were also used for analysis of other influencing factors. It was shown that: (1) generally the vegetation cover in different erosion regions displayed similar increasing trends; (2) spatially the vegetation cover was highest in the water erosion region, the second highest was in the freeze-thaw region and the lowest in the wind erosion region; and (3) vegetation cover in the Yellow River basin is influenced by climate factors, especially by temperature. In water erosion regions, the temporal change of vegetation cover seemed complicated by comprehensive climatic and human influences. In wind erosion regions, the vegetation cover had close relations to precipitation. In freeze-thaw erosion regions, the vegetation cover was primarily altered by temperature. In all the three erosion regions, significant change of the vegetation cover occurred from 2000 just after the 'Grain for Green' (GFG) programme was implemented throughout China. © 2010 John Wiley & Sons, Ltd.

Wang C.,Beijing Forestry University | Maclaren V.,University of Toronto
Forest Policy and Economics | Year: 2012

Based on data from a household survey the objective of the study was to evaluate the economic and social impacts of the Sloping Land Conversion Program (SLCP). The results indicate that the program was, in general, inefficient because productivity and environmental heterogeneity were given scant consideration in Northeast China. While the program has made a clear attempt to retire plots that are susceptible to soil erosion, there is room for better targeting. Fifty eight per cent of the families involved in afforestation considered themselves worse off after participating in SLCP. The families who experienced a decrease in income were more likely to claim that SLCP was an action forcibly imposed by the government. Although 60% supported the project, a fair proportion (16%) plan to return to cultivating forested areas and grassland once the subsidies of the project end in 2018. The government should widen alternative non-farm employment opportunities in order to ensure the sustainability of the program. © 2011 Elsevier B.V.

This letter answers some questions raised by "Comments on "Plantation development: Economic analysis of forest management in Fujian Province, China"", and discusses some existing problems in calculating NPVs, IRRs etc. in the paper. The letter also points out that the issues of rotation age, forest valuation and inflation rate etc. should be carefully considered in forest evaluation, but the main purpose of the study is to help decision makers choose the most reasonable scenario and values, not to cover all aspects of the matter. © 2014 Elsevier B.V.

Rao L.Y.,Beijing Forestry University | Sun G.,U.S. Department of Agriculture | Ford C.R.,U.S. Department of Agriculture | Vose J.M.,U.S. Department of Agriculture
Transactions of the ASABE | Year: 2011

Global climate change has direct impacts on watershed hydrology through altering evapotranspiration (ET) processes at multiple scales. There are many methods to estimate forest ET with models, but the most practical and the most popular one is the potential ET (PET) based method. However, the choice of PET methods for AET estimation remains challenging. This study explored ways to identify appropriate PET models for two small forested watersheds, one dominated by conifer plantation and one dominated by native naturally regenerated deciduous hardwoods, by using long-term hydrometeorological data collected at the Coweeta Hydrologic Laboratory in the humid Appalachians in the southeastern U.S. Our specific objectives were to: (1) contrast three common PET models (FAO-56 grass reference ET, Hamon PET, and Priestley-Taylor PET) and compare these PET estimates with measured AET at monthly and annual temporal scales, and (2) derive correction factors for the FAO-56 grass reference ET and Hamon PET models at the monthly scale using the Priestley-Taylor equation as the standard method for estimating forest PET. We found that different PET models gave significantly different PET estimates. The Priestley-Taylor equation gave the most reasonable estimates of forest PET for both watersheds. We conclude that the uncorrected Hamon and FAO PET methods would cause large underestimates of forest PET. Annual PET rates of the conifer watershed were higher than those of the native deciduous watershed due to the lower albedo (thus higher net radiation) in the former compared to the latter. Monthly correction factors provided useful tools for forest PET estimation in those areas lacking climatic data (i.e., radiation, humidity, and wind speed). © 2011 American Society of Agricultural and Biological Engineers.

Cao J.,SWST | Zhu L.,Beijing Forestry University
Wood and Fiber Science | Year: 2011

To investigate the time-dependent property of wood flour/polypropylene (PP) composites and the effect of coupling agents on it, both tensile stress relaxation and compressive stress relaxation curves were determined at various wood contents (0, 20, 30, 40, 50, 60, and 70%) without a coupling agent and were also determined at 50 and 60% wood contents with different coupling agents such as maleic anhydride grafted polypropylene (MAPP) and silane. Bending modulus of rupture (MOR) and modulus of elasticity (MOE) of wood flour/PP composites at various wood contents without coupling agents and at 60% wood content with MAPP and silane as coupling agents were also tested to compare with stress relaxation results. All measurements were performed at 26 ± 1°C. Results showed that 1) the tensile stress relaxation appeared to have similar trends with compressive stress relaxation (They both declined obviously after adding coupling agents at the same wood content.); 2) wood content had a great influence on stress relaxation behavior of wood flour/PP composites (The lowest stress relaxation rates appeared at 40% wood content for both tensile and compressive stress relaxation of wood flour/PP composites without coupling agent, suggesting the best compatibility between wood and PP is at about 40% within the experimental conditions of this study.); 3) optimal loading level of a coupling agent for stress relaxation varied with type of coupling agents and wood content (Within the experimental conditions used in this study, the optimal loading level for MAPP was 2% at both wood contents, whereas for silane, it was 1.5% at 50% wood content and 2% at 60% wood content.); and 4) lower stress relaxation rates corresponded to higher bending MOR and MOE values at 60% wood content. This suggests that long-term performance of wood flour/PP composites would be consistent with bending strength at room temperature.

Bussemaker M.J.,University of Western Australia | Xu F.,University of Western Australia | Xu F.,Beijing Forestry University | Zhang D.,University of Western Australia
Bioresource Technology | Year: 2013

The parameters, including ultrasonic frequency, still versus stirring, biomass particle size and biomass loading were concurrently investigated for the ultrasonic treatment of wheat straw. Experiments were conducted at three different frequencies; 40, 376, and 995. kHz using three different solid to liquid ratios, 1/50, 1/20, and 1/15. (g/ml), with and without mechanical stirring. Additional treatments in different particle size ranges, 0-0.5, 0.5-1, and 1-2. mm were performed at the solid to liquid ratio of 1/20. (g/ml). Fractionation was improved at 40 and 995. kHz via different mechanisms. Delignification was favored at the ultrasonic treatment frequency of 40. kHz, biomass loading 1/20. (g/ml) with stirring and particle size range of 0.5-1. mm. However at 995. kHz carbohydrate solubilization was favored, especially in the particle size range of <0.5. mm. The treatment efficacies highlighted the use of ultrasound for physical and chemical effects at different frequencies. © 2013 Elsevier Ltd.

Xu B.,Tsinghua University | Sun F.,Tsinghua University | Yang C.,University of Plymouth | Gao D.,Beijing Forestry University | Ren J.,Northwestern Polytechnical University
International Journal of Control | Year: 2011

In this article, the adaptive neural controller in discrete time is investigated for the longitudinal dynamics of a generic hypersonic flight vehicle. The dynamics are decomposed into the altitude subsystem and the velocity subsystem. The altitude subsystem is transformed into the strict-feedback form from which the discrete-time model is derived by the first-order Taylor expansion. The virtual control is designed with nominal feedback and neural network (NN) approximation via back-stepping. Meanwhile, one adaptive NN controller is designed for the velocity subsystem. To avoid the circular construction problem in the practical control, the design of coefficients adopts the upper bound instead of the nominal value. Under the proposed controller, the semiglobal uniform ultimate boundedness stability is guaranteed. The square and step responses are presented in the simulation studies to show the effectiveness of the proposed control approach. © 2011 Taylor & Francis.

Shen Z.,South China University of Technology | Luo Y.,South China University of Technology | Wang Q.,Iowa State University | Wang X.,South China University of Technology | And 2 more authors.
ACS Applied Materials and Interfaces | Year: 2014

This study reports the rapid preparation of silver nanoparticles (AgNPs) from Tollens' reagent under microwave irradiation. In the synthesis, lignin with reducing groups and spatial three-dimensional structure was used as reducing and stabilizing agents without other chemical reagents, and the effects of the ratio of lignin to Ag+, reaction temperature, and heating time on the synthesis of AgNPs were investigated. The obtained AgNPs were further characterized by UV-vis, Malvern particle size, TEM, XRD, and XPS analyses. The structural changes of lignin before and after reaction were also studied by FT-IR, 1H NMR, 13C NMR, and GC-MS. The results revealed that the obtained AgNPs were mostly spherical with diameters of around 24 nm. The optimum reaction conditions were a ratio 50 mg of lignin to 0.3 mM of Ag+, a microwave irradiation temperature of 60 °C, and a heating time of 10 min. Moreover, AgNPs redispersed well in water and ethanol after centrifugation for the removal of lignin. During the formation of AgNPs, lignin was oxidized, and the side chains of lignin were partly disrupted into small molecules, such as hydrocarbon and alcohol. The resultant lignin-AgNPs showed highly selective sensing detection for Hg2+, and the color of the lignin-AgNP solution containing Hg2+ decreased gradually with increasing amounts of Hg2+ within seconds, but the other 19 metal ions had little effect on the color and surface plasmon absorption band of the lignin-AgNPs. Also, there was a linear relationship between the absorbance and Hg2+ concentration, with a limit of detection concentration of 23 nM. This study provides not only a new way to take advantage of agricultural and forestry residues, but also a green and rapid method for the synthesis of AgNPs to detect the toxic ion Hg2+ selectively and sensitively. © 2014 American Chemical Society.

Lu S.,Beijing Forestry University | Guan X.,National Academy for Mayors of China | Zhou M.,Huazhong University of Science and Technology | Wang Y.,Guangzhou Institute of Geography
Environmental Management | Year: 2014

A large number of mathematical models have been developed to support land resource allocation decisions and land management needs; however, few of them can address various uncertainties that exist in relation to many factors presented in such decisions (e.g., land resource availabilities, land demands, land-use patterns, and social demands, as well as ecological requirements). In this study, a multi-objective interval-stochastic land resource allocation model (MOISLAM) was developed for tackling uncertainty that presents as discrete intervals and/or probability distributions. The developed model improves upon the existing multi-objective programming and inexact optimization approaches. The MOISLAM not only considers economic factors, but also involves food security and eco-environmental constraints; it can, therefore, effectively reflect various interrelations among different aspects in a land resource management system. Moreover, the model can also help examine the reliability of satisfying (or the risk of violating) system constraints under uncertainty. In this study, the MOISLAM was applied to a real case of long-term urban land resource allocation planning in Suzhou, in the Yangtze River Delta of China. Interval solutions associated with different risk levels of constraint violation were obtained. The results are considered useful for generating a range of decision alternatives under various system conditions, and thus helping decision makers to identify a desirable land resource allocation strategy under uncertainty. © 2014 Springer Science+Business Media.

Wang T.,Beijing Forestry University
Nonlinear Analysis: Real World Applications | Year: 2016

This paper establishes a regularity criterion of strong solutions to the two-dimensional compressible magnetohydrodynamic (MHD) flows. The criterion depends on the density, but is independent of the velocity and the magnetic field. More precisely, once the strong solutions blow up, the L∞-norm for the density tends to infinity. In particular, the vacuum in the solutions is allowed. © 2016 The Author. Published by Elsevier Ltd.

Qi F.,Hong Kong Polytechnic University | Qi F.,Beijing Forestry University | Chu W.,Hong Kong Polytechnic University | Xu B.,Chinese Research Academy of Environmental Sciences
Applied Catalysis B: Environmental | Year: 2013

In this study, the performance of caffeine degradation and mineralization in aqueous phase by a catalyst that was prepared by incorporating cobalt into the structure of MCM41 (i.e. Co-MCM41) in activating peroxymonosulfate (PMS) was explored. Experimental results showed that Co-MCM41 activated PMS not only degraded caffeine, but also mineralized the corresponding intermediates successfully. The surface and structure properties of Co-MCM41 were characterized by several analytical methods. The leaching of cobalt ions in this process was very low, and the heterogeneous reaction dominated the caffeine decay rather than the homogeneous one, which made the reuse of catalyst highly feasible. According to the result of using quenchers, both OH and SO4 - were found in this process and the latter was the major oxidant species. Furthermore, nine major intermediates generated in this process were identified and the degradation pathway was proposed. © 2013 Elsevier B.V.

Song X.,North Carolina State University | Song X.,Beijing Forestry University | Hubbe M.A.,North Carolina State University
Holzforschung | Year: 2014

The hypothesis has been tested that a carboxymethyl hemicellulose improves more effectively the dry strength of papers than a native hemicellulose. To that end, β-d-glucan from oat was treated with an alkaline ethanolic solution of sodium chloroacetate for different times to obtain a range of carboxymethylated β-d-glucan (CM-glucan) samples. The derivatization was confirmed by Fourier transform infrared spectroscopy and elemental analysis. The physical properties of paper concerning burst and tensile strength as well as folding endurance were essentially improved if CM-glucan was added to unbleached kraft fiber suspension from pine before papermaking. The effects could be maximized by a proper selection of carboxymethylation time and the amount of CM-glucan added to the suspension. The effect was also beneficial in the case of recycled fibers.

Jiang J.,Nanjing Forestry University | Jiang J.,Beijing Forestry University
Journal of Reinforced Plastics and Composites | Year: 2016

Based on the anatomical and chemical properties, a representative volume unit was studied to predict the longitudinal elastic modulus of bamboo (Phyllostachys glauca McClure). Microstructure features and chemical characterization of bamboo were obtained. Elastic constant of cell wall in length was derived by the application of rule of mixture. Taking advantage of the representative volume unit model, the longitudinal elastic modulus prediction formula of bamboo was established, and the theoretical and experimental value were calculated. The results showed that modified formula was acceptable to predict the longitudinal elastic modulus value with the error rate between predicted and experimental values below 25%. It is feasible to simplify the microstructure to calculate the longitudinal elastic modulus by model. © SAGE Publications.

Liu H.-M.,Henan University of Technology | Li M.-F.,Beijing Forestry University
Chemical Engineering and Technology | Year: 2014

Hydrothermal liquefaction of cypress was performed in an autoclave with various amounts of water. The obtained acid-soluble and acid-insoluble solid residues were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, sugar analysis, elemental analysis, and nuclear magnetic resonance to help understand the reaction mechanisms of this process. The characteristics of solid residues were significantly affected by the water amount. Cellulose was more stable at high water amount and hemicelluloses were much more reactive than cellulose. Comparison of nuclear magnetic resonance spectra of milled wood lignin and milled solid residues indicated a significant cleavage of the side chains. The components of milled solid residues were mainly derived from decomposition and repolymerization of lignin. The decomposition of the side chains was substantial for lignin depolymerization during hydrothermal liquefaction. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xu X.,Beijing Forestry University | Luo J.,Tsinghua University | Guo D.,Tsinghua University
Journal of Colloid and Interface Science | Year: 2011

Although nanoparticle impacts on a solid surface always occur in natural or engineering processes and cause extensive investigations, less works have been reported on the nanoparticle-wall collisions in a liquid. In present paper, by considering the inertial effect and the Brownian motion of nanoparticles, a theoretical model was established for calculating the collision frequency between the nanoparticles and the solid surface in a laminar cylindrical liquid jet impacting normally on the solid surface. The analysis showed that the collision frequency grows as the square root of the impacting speed for low impacting speed regime in which the Brownian motion is predominant, whereas increases as the second power of the impacting speed for high impacting speed regime in which the inertial effect is predominant. Meanwhile, an observation system for nanoparticle-wall collisions in a laminar cylindrical liquid jet has been developed. The adsorption of the nanoparticles on the solid surface after collision has also been observed. Because of their lower attractive energy with the solid surface, these adsorbed nanoparticles are easier to be removed by the Fundamental Research Funds for the Central Universities (Grant No. YX2011-9), the Beijing Forestry University Young Scientist Fund (Grant No. 2010BLX08), the hydrodynamic force of the impacting liquid than that deposited on a dry surface. © 2011 Elsevier Inc.

Shi X.-G.,Beijing Forestry University
International Journal of Geometric Methods in Modern Physics | Year: 2013

In general, topological quantum field theory (TQFT) is studied in detail from the n-dimensional cobordism (nCob) to the Hilbert vector space. However, we study the TQFT in the different way in this paper, that is, the TQFT is studied from the Hilbert vector space to nCob. To do this, the theory called the φ-mapping topological current theory is used. The relation between the objects and zero points of the Hilbert states in the Hilbert vector space is studied in this frame. The relation between the morphism and topological current is revealed too. © 2013 World Scientific Publishing Company.

Xu Y.,Beijing Forestry University | Li W.,Zhejiang Agriculture And forestry University
International Journal of Advancements in Computing Technology | Year: 2012

Since the environment in the forest is relatively complicated and there's a necessity to avoid the dead zone of signal diffraction when laying wireless sensor in the forest, the integration of SBR and UTD is applied to study the impact of 2.4GHz radio-frequency signal on the path loss characteristics in the forest. This paper achieved the ray location from the receive pint to field point by using back-ray tracing method and computed the response electric field relative to each ray by using UTD. Take the poplar planted forest for instance. The measured value and simulated value were compared, finding good consistency between them, which indicates that SBR and UTD can effectively predict the path loss characteristics in the forest.

Lan W.,South China University of Technology | Liu C.-F.,South China University of Technology | Sun R.-C.,South China University of Technology | Sun R.-C.,Beijing Forestry University
Journal of Agricultural and Food Chemistry | Year: 2011

Lignocellulose materials are potentially valuable resources for transformation into biofuels and bioproducts. However, their complicated structures make it difficult to fractionate them into cellulose, hemicelluloses, and lignin, which limits their utilization and economical conversion into value-added products. This study proposes a novel and feasible fractionation method based on complete dissolution of bagasse in 1-butyl-3-methylimidazolium chloride ([C 4mim]Cl) followed by precipitation in acetone/water (9:1, v/v) and extraction with 3% NaOH solution. The ionic liquid [C 4mim]Cl was easily recycled after concentration and treatment with acetonitrile. 1H NMR analysis confirmed that there was no obvious difference between the recycled [C 4mim]Cl and fresh material. Bagasse was fractionated with this method to 36.78% cellulose, 26.04% hemicelluloses, and 10.51% lignin, accounting for 47.17 and 33.85% of the original polysaccharides and 54.62% of the original lignin, respectively. The physicochemical properties of the isolated fractions were characterized by chemical analysis, high-performance anion exchange chromatography (HPAEC), gel permeation chromatography (GPC), Fourier transform infrared (FT-IR), and 1H and 2D 13C- 1H correlation (HSQC) nuclear magnetic resonance spectroscopy. The results showed that the acetone-soluble lignin and alkaline lignin fractions had structures similar to those of milled wood lignin (MWL). The easy extraction of the noncellulose components from homogeneous bagasse solution and amorphous regenerated materials resulted in the relatively high purity of cellulosic fraction (>92%). The hemicellulosic fraction was mainly 4-O-methyl-d-glucuronoxylans with some α-l- arabinofuranosyl units substituted at C-2 and C-3. © 2011 American Chemical Society.

Liu J.,Beijing Forestry University | Liu J.,International Institute For Applied Systems Analysis | Folberth C.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Yang H.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | And 4 more authors.
PLoS ONE | Year: 2013

Food security and water scarcity have become two major concerns for future human's sustainable development, particularly in the context of climate change. Here we present a comprehensive assessment of climate change impacts on the production and water use of major cereal crops on a global scale with a spatial resolution of 30 arc-minutes for the 2030s (short term) and the 2090s (long term), respectively. Our findings show that impact uncertainties are higher on larger spatial scales (e.g., global and continental) but lower on smaller spatial scales (e.g., national and grid cell). Such patterns allow decision makers and investors to take adaptive measures without being puzzled by a highly uncertain future at the global level. Short-term gains in crop production from climate change are projected for many regions, particularly in African countries, but the gains will mostly vanish and turn to losses in the long run. Irrigation dependence in crop production is projected to increase in general. However, several water poor regions will rely less heavily on irrigation, conducive to alleviating regional water scarcity. The heterogeneity of spatial patterns and the non-linearity of temporal changes of the impacts call for site-specific adaptive measures with perspectives of reducing short- and long-term risks of future food and water security. © 2013 Liu et al.

Fan K.,Beihang University | Yang X.,Beihang University | Liu J.,Beijing Forestry University | Rong L.,Beihang University
RSC Advances | Year: 2015

In order to assess the La effect on reducing carbonaceous deposition (coke) on catalysts for the hydrocracking of Jatropha oil, NiW/nHA, NiW/Al2O3 and NiW/HY catalysts modified with loaded La were synthesized and studied. The catalysts were characterized by N2 adsorption-desorption, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of ammonia (NH3-TPD), temperature programmed desorption of hydrogen (TPD-Hads), and temperature-programmed desorption of carbon dioxide (CO2-TPD). The species and the amount of coke on the hydrocracking catalyst were measured by Fourier transform infrared (FT-IR) spectroscopy, solid state 13C nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA), demonstrating that the coke was constituted of polyaromatic hydrocarbons and that the La catalyst loading had a very positive effect on coke reduction. The amount of coke on NiW/nHA, NiW/Al2O3 and NiW/HY catalysts decreased respectively by 0.94%, 1.19%, 1.91% after 8 h and 1.66%, 1.89%, 3.78% after 180 h. The catalytic stability and the catalyst lifetime were also improved by La loading. © The Royal Society of Chemistry 2015.

Lan W.,South China University of Technology | Liu C.-F.,South China University of Technology | Yue F.-X.,South China University of Technology | Sun R.-C.,South China University of Technology | And 2 more authors.
Carbohydrate Polymers | Year: 2011

Ultrasound-assisted dissolution of cellulose was performed in ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl). The dissolution process was monitored with polarizing microscope. The effects of parameters including ultrasonic power and irradiation time on cellulose dissolution time were investigated. The dissolution time required for complete dissolution decreased from 190 min without assistance to 60 min irradiated with 30 W ultrasound for 20 min. The regenerated cellulose samples were characterized with FT-IR, solid-state CP/MAS 13C NMR, wide-angle X-ray diffraction and thermal analysis. The results showed that most crystalline structure of cellulose was destroyed to amorphous structure, and the remained crystalline structure of cellulose was converted to cellulose II from cellulose I in native cellulose. After dissolution and regeneration in ionic liquid, the thermal stability of cellulose decreased and the pyrolysis residues increased. © 2011 Elsevier Ltd All rights reserved.

Wang Q.,Xidian University | Wang Q.,Northwest University, China | Yun Y.,Beijing Forestry University
Microchimica Acta | Year: 2012

We have investigated the oxidative electrochemistry of nitrite on glassy carbon electrodes modified with cobalt nanoparticles, poly(3,4-ethylenedioxythiophene) (PEDOT), and graphene. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The results suggest that this new type of electrode combines the advantages of PEDOT-graphene films and cobalt nanoparticles and exhibits excellent electrocatalytic activity towards the oxidation of nitrite. There is a linear relationship between the peak current and the nitrite concentration in the range from 0. 5 μM to 240 μM, and the detection limit is 0. 15 μM. The modified electrodes also enable the determination of nitrite at low potentials where the noise level and interferences by other electro-oxidizable compounds are weak. © 2012 Springer-Verlag.

Damerell P.,Imperial College London | Damerell P.,Beijing Forestry University | Howe C.,Imperial College London | Milner-Gulland E.J.,Imperial College London
Environmental Research Letters | Year: 2013

Environmental education is frequently undertaken as a conservation intervention designed to change the attitudes and behaviour of recipients. Much conservation education is aimed at children, with the rationale that children influence the attitudes of their parents, who will consequently change their behaviour. Empirical evidence to substantiate this suggestion is very limited, however. For the first time, we use a controlled trial to assess the influence of wetland-related environmental education on the knowledge of children and their parents and household behaviour. We demonstrate adults exhibiting greater knowledge of wetlands and improved reported household water management behaviour when their child has received wetland-based education at Seychelles wildlife clubs. We distinguish between 'folk' knowledge of wetland environments and knowledge obtained from formal education, with intergenerational transmission of each depending on different factors. Our study provides the first strong support for the suggestion that environmental education can be transferred between generations and indirectly induce targeted behavioural changes. © 2013 IOP Publishing Ltd.

Zhang P.,Beijing Forestry University | Zhang G.,Renmin University of China | Dong J.,Hunan University | Fan M.,University of Wyoming | Zeng G.,Hunan University
Separation and Purification Technology | Year: 2012

Recently there has been increasing concerns on widespread occurrence of endocrine disrupting chemicals (EDCs) in aquatic environment. Bisphenol A (BPA) in water was oxidized as a target EDC by K2FeO4 (Fe(VI)) in this study. The results showed that BPA was effectively removed within a broad initial water pH range of 5.0-9.5, especially under a weak acidic condition between the initial pH 5 and 6. When the initial BPA concentration was about 1.5 mg L-1, BPA could be completely removed with a oxidation time of 30 min and a Fe(VI)/BPA molar ratio of 3.0. After Fe(VI) oxidation, UV254 of the water samples significantly increased, indicating that BPA degradation intermediates and end products still contained phenyl ring. Further online UV scanning showed that the UV absorbance obviously changed within the UV range of 190-215 nm and 230-300 nm during Fe(VI) oxidation. The DOC of water samples reduced with the increase of Fe(VI) dosage and prolonging of oxidation time, and about 50% of BPA was mineralized after Fe(VI) oxidation under a Fe(VI)/BPA molar ratio of 4.0. The influences of coexisting constituents such as humic acids, SiO32-, HCO3- and tert-butanol were studied. The results showed that humic acids and SiO32- notably inhibited the BPA removal; tert-butanol slightly decreased the BPA removal; and the existence of HCO3- slightly enhanced the BPA removal. © 2011 Elsevier B.V. All rights reserved.

Zhang C.-Y.,Beijing Forestry University
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2014

Niche theory, the neutral theory and nearly neutral theory tend to explain community assemblage mechanism at the community level. Theoretical foundations explaining the phenomenon of community ecology using species interactions and population dynamics theory are still very weak. Establishing relations between population ecology and community ecology and integrating the theories of population ecology and community ecology, will greatly promote the rapid development of the theories on community assemblage. This paper reviewed the development of community assemblage theories, including ecological niche theory and the neutral theory, and mainly sorted out research advances of community assemblage based on the population dynamics and species interactions. Population dynamics processes include birth, death, immigration and emigration. On the basis of basic population dynamics process, the species abundance distribution can be described by Dirichlet model and neutral theory model. With individual species-area relationship (ISAR) model and Ripley K function, describing species richness around target species at different scales from the perspective of individual plant becomes realized. Asymmetric competition is common in adjacent relations of plant communities, which presents the unequal allocations of resources among the competitive plants. Combining ISAR model and the phenomenon of asymmetric competition, the evaluation methods and theories regarding the assemblage of neighborhood diversity were discussed from the perspective of species interactions. ©, 2014, Beijing Forestry University. All right reserved.

Wang P.,Beijing Forestry University | Wang P.,Peking University | Chen G.Q.,Peking University
Journal of Hydrology | Year: 2016

Closely related to the solar photocycle, plankton growth in eutrophic waters displays a diurnal variation because of photosynthesis and respiration. Presented in this paper is an analytical study of the diurnal variation of mean concentration of plankton and nutrient in an open channel eutrophic flow initiated by an instantaneous emission. The evolution of the concentration is shown driven by the combination of hydraulic dispersion and diurnal reaction between plankton and nutrient. The analytical solution for longitudinal distribution of concentration is rigorously derived and illustrated, based on the time dependent hydraulic dispersivity. Numerical results are presented and characterized by the reaction rate, yield factor and period for the diurnal reaction and the P. éclet number of the flow. For typical applications such as ecological risk assessment and environmental impact assessment, the upper and lower limits of critical length and duration of five typical pollutant concentrations are concretely illustrated for given concentration criterions. Remarkable diurnal variations are revealed up to around one third in the critical length and duration for plankton, and about ten percent for nutrient. © 2016 Elsevier B.V.

Dou X.,Beijing Forestry University | Mohan D.,Jawaharlal Nehru University | Pittman C.U.,Mississippi State University
Water Research | Year: 2013

Schwertmannite was synthesized on a 2 m3-scale and fabricated to irregular, cylindrical and spherical shape granules using drum granulation, extrusion and spray coating, respectively. The granules were systematically evaluated for As(V) removal from drinking water in terms of both performance and safety. The irregular and cylindrical shape granules (IS and CS) had larger schwertmannite loadings, higher porosity, more abundant pore structure and larger micropore volumes than those with a spherical shape (SS). As(V) adsorption kinetics on IS, CS and SS schwertmannite granules followed a pseudo-second order rate equation and two-stages of intraparticle diffusion. The rate parameters were in an order of IS > CS > SS granules. The faster uptake kinetics of the IS granules was due to their largest pore volume and interparticle porosity. Furthermore, adsorption capacities of 34, 21 and 5 mg/g, for IS, CS and SS granular schwertmannite samples were achieved at an initial As(V) concentration of 20 mg/L and adsorbent dose of 0.5 g/L. IS and CS samples performed much better over a wide pH range versus SS samples. Except for humic acid, PO43- and SiO44- did not inhibit As(V) adsorption on IS and CS granular specimens. SS samples worked poorly even in the absence or presence of co-existing anions. Regeneration was achieved using 0.1 M NaOH. The recycled IS and CS granular specimens can be used for 4 different cycles with no or nominal loss of adsorption capacity. Column experiments were also conducted. The IS, CS and SS granular specimens treated 8100, 4200 and 120 bed volumes (BVs) of contaminated water. No heavy metals leached from the packed granular adsorbent and appeared in the column effluent. Furthermore, the toxicity characteristic leaching procedure (TCLP) showed that the spent IS and CS granules were inert and could safely be disposed of in landfills. In short, irregular-shaped granules (IS) fabricated by drum granulation is a good candidate for arsenic removal from drinking water with a high future application potential. © 2013 Elsevier Ltd.

Seburanga J.L.,National University of Rwanda | Zhang Q.,Beijing Forestry University
Journal of Forestry Research | Year: 2013

Trees play a key role in neighborhood landscapes, a belief that has been widely held for millennia in areas beyond Sub-Saharan Africa. Unfortunately, awareness of modern landscape architecture was almost absent in Rwanda until the late 20th century. Today, houses with surrounding decorative and amenity plants are a common feature in Rwanda's neighborhood landscapes and, as the villagization of settlements progresses, new kinds of landscapes are emerging. This paper explores neighborhood tree planting around human settlements in the country. Remote sensing, photogrammetry, photo interpretation, and plant surveys were the core methods used. The average tree cover fraction ranged between 10%-35%. As the result of what is hereafter referred to as the "luxury effect," a discrete gradient was detected along which the diversity of ornamental and amenity trees increases with the socio-economic status of neighborhoods: from rural settlements to urban residences via a series of intermediate designs, in which different levels of human-built vegetated areas alternate with non-landscaped spaces. Showy, non-productive amenity trees tend to occur more in wealthy quarters of the inner core of cities while edible ornamentals and other productive neighborhood trees prevail in rural and spontaneous settlements. In general, the practice of landscape plant design, in spite of its constant improvement, is still striving to get established as a profession in the country. © 2013 Northeast Forestry University and Springer-Verlag Berlin Heidelberg.

Xu Z.,Beijing Forestry University
Molecular genetics and genomics : MGG | Year: 2014

MADS-box genes encode transcription factors that play crucial roles in plant development, especially in flower and fruit development. To gain insight into this gene family in Prunus mume, an important ornamental and fruit plant in East Asia, and to elucidate their roles in flower organ determination and fruit development, we performed a genome-wide identification, characterisation and expression analysis of MADS-box genes in this Rosaceae tree. In this study, 80 MADS-box genes were identified in P. mume and categorised into MIKC, Mα, Mβ, Mγ and Mδ groups based on gene structures and phylogenetic relationships. The MIKC group could be further classified into 12 subfamilies. The FLC subfamily was absent in P. mume and the six tandemly arranged DAM genes might experience a species-specific evolution process in P. mume. The MADS-box gene family might experience an evolution process from MIKC genes to Mδ genes to Mα, Mβ and Mγ genes. The expression analysis suggests that P. mume MADS-box genes have diverse functions in P. mume development and the functions of duplicated genes diverged after the duplication events. In addition to its involvement in the development of female gametophytes, type I genes also play roles in male gametophytes development. In conclusion, this study adds to our understanding of the roles that the MADS-box genes played in flower and fruit development and lays a foundation for selecting candidate genes for functional studies in P. mume and other species. Furthermore, this study also provides a basis to study the evolution of the MADS-box family.

Song X.,Beijing Forestry University | Song X.,North Carolina State University | Hubbe M.A.,North Carolina State University
Carbohydrate Polymers | Year: 2014

An enhanced bonding agent for papermaking was prepared by selective oxidation of a hemicellulose-rich byproduct of oat processing, which will be identified here by its primary component, β-d-glucan. The β-d-glucan was treated sequentially with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and sodium hypochlorite, or alternatively just with sodium hydroxide. When added to a slurry of unbleached softwood kraft fibers, in combination with an optimal dosage of aluminum sulfate, the oxidized β-d-glucan yielded greater increases in tensile strength and folding endurance in comparison to untreated β-d-glucan. NaOH treatment also improved dry-strength performance of the β-d-glucan, except for folding endurance. The improvements were attributed to increased charge density of the treated polyelectrolytes, leading to better distribution and retention on fibers prior to sheet formation. Modified β-d-glucan also enhanced the strength of recycled sheets when the treated paper was repulped and formed into recycled paper with no further chemical addition. © 2013 Elsevier Ltd. All rights reserved.

Guo X.-M.,Hebei Normal University of Science and Technology | Xiao X.,Hebei Normal University of Science and Technology | Wang G.-X.,Chinese Academy of Forestry | Gao R.-F.,Beijing Forestry University
Frontiers in Plant Science | Year: 2013

Kiwi fruit is of great agricultural, botanical, and economic interest. The flower of kiwi fruit has axile placentation, which is typical for Actinidiaceae. Axile placentation is thought derived through fusion of conduplicate carpels with marginal placentation according to the traditional doctrine. Recent progress in angiosperm systematics has refuted this traditional doctrine and placed ANITA clade rather than Magnoliaceae as the basalmost clade. However, the former traditional doctrine stays in the classrooms as the only teachable theory for the origin of carpels. To test the validity of this doctrine, we performed anatomical study on kiwi fruit. Our study indicates that the placenta has a vascular system independent of that of the ovary wall, the ovules/seeds are attached to the placenta that is a continuation of floral axis enclosed by the lateral appendages that constitute the ovary wall, and there are some amphicribral bundles in the center of placenta and numerous amphicribral bundles supplying ovules/seeds in kiwi fruit. The amphicribral vascular bundles supplying the ovules/seeds are comparable to those usually seen in branches, but not comparable to those seen in leaves or their derivatives. This comparison indicates that the placenta in kiwi fruit cannot be derived from the fusion of collateral ventral bundles of conduplicate carpels, as suggested by traditional doctrine. Instead the vascular organization in placenta of kiwi suggests that the placenta is a shoot apex-bearing ovules/seeds laterally. This conclusion is in line with the recently raised Unifying Theory, in which the placenta is taken as an ovule-bearing branch independent of the ovary wall (carpel in strict sense). Similar vascular organization in placenta has been seen in numerous isolated taxa besides kiwi fruit. Therefore whether such a pattern is applicable for other angiosperms is an interesting question awaiting answering. © 2013 Guo, Xiao, Wang and Gao.

Dai Y.-C.,Beijing Forestry University | Xue H.-J.,CAS Shenyang Institute of Applied Ecology | Vlasak J.,Academy of Sciences of the Czech Republic | Rajchenberg M.,Centro Forestal CIEFAP | And 2 more authors.
Fungal Diversity | Year: 2014

Polyporus accommodates species with stipitate basidiocarps, a dimitic hyphal system with skeleto-binding hyphae, and hyaline, thin-walled, more or less cylindrical basidiospores. The species of Polyporus are divided into six morphological groups, of which Melanopus is characterized by coriaceous basidiocarps, thin context and a black cuticle on the stipe. In this study, we explore the phylogeny and species diversity of Polyporus sensu lato focusing on the group Melanopus based on global samples. Our combined ITS and nLSU dataset included 117 collections represented by 117 ITS and 94 nLSU sequences, of which 43 ITS and 37 nLSU sequences were newly generated. The resulting phylogenetic analysis recovered four clades, Favolus, Neofavolus, Melanopus and Polyporellus clades, while several species in the morphological groups Melanopus and Polyporus were outside these clades. Combined with morphological evidence, three new species in the Melanopus clade, Polyporus americanus, P. austroandinus and P. conifericola, are newly described and illustrated, and their distinctive characters are discussed. The illegitimate name Polyporus fraxineus is renamed as Polyporus fraxinicola. The phylogeny and taxonomy of each species in group Melanopus (morphology) or Melanopus clade (phylogeny) and related species are briefly discussed. © 2013 Mushroom Research Foundation.

Tang L.,Beijing Forestry University | Shangguan W.-B.,South China University of Technology
Measurement: Journal of the International Measurement Confederation | Year: 2011

An improved Trifilar Torsional Pendulum (TTP) for the experimental determination of the Center of Gravity (C.G.) and inertia tensor (the three moments of inertia and the three products of inertia) for an irregular-shaped body is proposed and developed. In the improved apparatus, a universal joint is adopted to facilitate the adjustments of the C.G. of the body in line with the pendulum axis. To enhance the precision of the measurement, a tri-coordinate measuring machine is employed to measure the coordinates of the predefined points and vectors of axes, which are then used for calculating the C.G. and inertia tensor for an irregular-shaped body. The theoretical fundaments of an improved TTP, the experimental setup, data processing procedures, and error estimation for measuring C.G. and inertia tensor are presented. With the proposed TTP and data processing procedure, the relative error in the determination of the moments of inertia can be estimated within 1%, and the deviation of the measured C.G. to the theoretical C.G. is within 1.5 mm. An example is given to demonstrate the effectiveness of the new approaches. © 2011 Published by Elsevier Ltd. All rights reserved.

Peng X.,South China University of Technology | Zhong L.,South China University of Technology | Ren J.,South China University of Technology | Sun R.,South China University of Technology | Sun R.,Beijing Forestry University
Composites Part A: Applied Science and Manufacturing | Year: 2010

This paper is an attempt to investigate the influences of enzyme (laccase) and alkali treatments on the surface lignin of single cellulose fibre. The fibre surface characteristics and the interfacial behaviour of the sisal fibre/phenolic resin composites were also studied by SEM, AFM, XPS. The surface lignin greatly affected the surface physical and chemical properties of single cellulose fibres. The surface lignin concentration was up to 35% for the raw fibre without any treatment, and then it decreased to 24%, 20% and 18% for the fibres with laccase treatment, alkali treatment and laccase/alkali treatment, respectively. The removal of lignin from fibre surface could enhance the interfacial strength of composites, and thus increase the tensile strength and internal bonding strength by 43% and 51%, respectively, for the composites obtained from laccase/alkali treated fibres. © 2010 Elsevier Ltd. All rights reserved.

Wang X.,South China University of Technology | Liu B.,South China University of Technology | Ren J.,South China University of Technology | Liu C.,South China University of Technology | And 3 more authors.
Composites Science and Technology | Year: 2010

Quaternized carboxymethyl chitosan (QCMC) was intercalated into the interlayer of rectorite (REC) to prepare QCMC/REC nanocomposite. XRD and TEM results revealed that REC was well dispersed in the polymer matrix and obtained the largest interlayer distance when the mass ratio of QCMC to REC was 2:1. FTIR, NMR and zeta-potential analyses showed that the intercalation of QCMC did not destroy the structure of REC layer, but there were hydrogen-bonding and electrostatic interactions between QCMC and REC. Quaternized chitosan (HTCC)/REC nanocomposite was prepared and studied in parallel. The comparative analysis of the two biopolymer/clay nanocomposites indicated that the free volume and positive charge density of biopolymers were important factors that affected the intercalation of biopolymer into clay. At last, thermal analysis indicated that QCMC/REC nanocomposites had obviously higher thermal stability in comparison with QCMC. This study shows that the combination with clay materials is a functional way to expand the possible application of QCMC as drug controlled-release carriers, antimicrobial agent and pulp-cap. © 2010 Elsevier Ltd.

Zhang X.-Y.,Beijing Forestry University | Fang Q.,Yamagata University
International Journal of Automation and Computing | Year: 2016

In this paper, effects of environmental and hunting parameters on the interspecific interacting populations are considered by applying the Rosenzweig-MacArthur model with the Holling type II functional response. Attenuating functions of the carrying capacity are introduced with a concern on the hunting parameters. We carry out numerical study to investigate how the population densities behave when environmental quantities change. We obtain the Hopf bifurcation diagrams from numerical results. © 2016 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg

Huang B.,Rutgers University | Rachmilevitch S.,Rutgers University | Rachmilevitch S.,Desert Research Institute | Xu J.,Rutgers University | Xu J.,Beijing Forestry University
Journal of Experimental Botany | Year: 2012

Extensive past efforts have been taken toward understanding heat tolerance mechanisms of the aboveground organs. Root systems play critical roles in whole-plant adaptation to heat stress, but are less studied. This review discusses recent research results revealing some critical physiological and metabolic factors underlying root thermotolerance, with a focus on temperate perennial grass species. Comparative analysis of differential root responses to supraoptimal temperatures by a heat-adapted temperate C3 species, Agrostis scabra, which can survive high soil temperatures up to 45 °C in geothermal areas in Yellow Stone National Park, and a heat-sensitive cogeneric species, Agrostis stolonifera, suggested that efficient carbon and protein metabolism is critical for root thermotolerance. Superior root thermotolerance in a perennial grass was associated with a greater capacity to control respiratory costs through respiratory acclimation, lowering carbon investment in maintenance for protein turnover, and efficiently partitioning carbon into different metabolic pools and alternative respiration pathways. Proteomic analysis demonstrated that root thermotolerance was associated with an increased maintenance of stability and less degradation of proteins, particularly those important for metabolism and energy production. In addition, thermotolerant roots are better able to maintain growth and activity during heat stress by activating stress defence proteins such as those participating in antioxidant defence (i.e. superoxide dismutase, peroxidase, glutathione S-transferase) and chaperoning protection (i.e. heat shock protein). © 2012 The Author.

Li X.,South China University of Technology | Liu B.,South China University of Technology | Ye W.,South China University of Technology | Wang X.,South China University of Technology | And 2 more authors.
Materials Chemistry and Physics | Year: 2015

Silver nanoparticles (Ag NPs) were synthesized greenly into the lamellar space of rectorite (REC) with quaternized carboxymethyl chitosan (QCMC), meanwhile quaternized carboxymethyl chitosan/rectorite/silver bionanocomposite was obtained. Results showed that QCMC and rectorite acted as reducing agent and solid support for Ag NPs, respectively. Exfoliated rectorite (REC) and organic rectorite (OREC) were obtained, simultaneously Ag NPs were formed on their interlayer and external surface. With the confinement effect of rectorite, the average diameters of Ag NPs changed from 45 nm to 22 nm, along with the change in size distributions from 30-65 nm to 18-28 nm, and their shapes changed from sphere to oval. The obtained quaternized carboxymethyl chitosan/rectorite/silver bionanocomposites were made into beads (∼1 mm) to catalyze the reduction of 4-nitrophenol (4-NP), the catalytic rate followed the order: the beads with OREC > those with REC > those without rectorite. The beads with quaternized carboxymethyl chitosan/rectorite/silver bionanocomposites without any treatments still performed well for four consecutive catalytic experiments. Using rectorite to stabilize Ag NPs and get smaller Ag NPs with narrower size distribution may extend the synthesis strategy of other nanoparticles. © 2014 Elsevier B.V. All rights reserved.

Zhang S.-B.,CAS Kunming Institute of Botany | Zhang S.-B.,CAS Xishuangbanna Tropical Botanical Garden | Yin L.-X.,Beijing Forestry University
Botanical Studies | Year: 2012

Meconopsis horridula var. racemosa, a valuable horticultural and medicinal plant, grows in the high mountains of the Himalayas under a range of light intensities, from bright illumination on the screes to low light in the understory of shrubs. To understand how this species adapts to these various environments, we examined the relative significance of leaf traits and physiology on photosynthetic light acclimation. Compared with plants exposed to low growth irradiance, those under greater irradiance exhibited a higher photosynthetic rate, leaf nitrogen content per unit area (Na), leaf dry mass per unit area (LMA), chlorophyll a/b ratio and CO2 diffusion conductance. However, photosynthetic nitrogen-use efficiency and leaf N content per unit mass remained relatively constant regardless of light regime. This change in photosynthetic rate under different light conditions was linked to Na, LMA and CO2 diffusion conductance. Our results show that M. horridula has high photosynthetic plasticity in response to growth irradiance, and that photosynthetic performance is better from plants grown under brighter illumination. Such findings will be beneficial when developing a cultivation strategy in commercial production.

Liu J.,Beijing Forestry University | Liu J.,International Institute For Applied Systems Analysis | Yang H.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Journal of Hydrology | Year: 2010

An accurate estimate of global water uses with high spatial resolution is a key to assessing global water scarcity and to understanding human's interference with the ecosystems. In spite of the progress made previously, there is a lack of spatially explicit assessment of both green and blue water uses in agriculture. In this paper, we estimated consumptive water use (CWU) in cropland on a global scale with a spatial resolution of 30 arc-minutes. A GIS-based version of the EPIC model, GEPIC, is used for the estimation. The results show that in crop growing periods, global CWU was 5938 km3 a-1 in cropland around the year 2000, of which green water contributed to 84%. On an annual basis, global CWU was 7323 km3 a-1 in cropland, of which green water contributed to 87%. We compared the simulated consumptive blue water use (CBWU) with the statistical CBWU at the national level among individual countries, and at the federal state or province level in the USA and China. The comparison indicates a good agreement between the simulated and statistical CBWU, suggesting a satisfactory performance of the GEPIC model and reliability of the estimation in irrigated cropland. The importance of green water in both crop production and food trade calls for a better management of green water, in addition to blue water. © 2009 Elsevier B.V. All rights reserved.

Bai Z.-Y.,Beijing Forestry University
The Scientific World Journal | Year: 2013

This paper proposes an improved score function for the effective ranking order of interval-valued intuitionistic fuzzy sets (IVIFSs) and an interval-valued intuitionistic fuzzy TOPSIS method based on the score function to solve multicriteria decision-making problems in which all the preference information provided by decision-makers is expressed as interval-valued intuitionistic fuzzy decision matrices where each of the elements is characterized by IVIFS value and the information about criterion weights is known. We apply the proposed score function to calculate the separation measures of each alternative from the positive and negative ideal solutions to determine the relative closeness coefficients. According to the values of the closeness coefficients, the alternatives can be ranked and the most desirable one(s) can be selected in the decision-making process. Finally, two illustrative examples for multicriteria fuzzy decision-making problems of alternatives are used as a demonstration of the applications and the effectiveness of the proposed decision-making method. © 2013 Zhi-yong Bai.

Xu Bingbing B.,Chinese Research Academy of Environmental Sciences | Xu Bingbing B.,Harbin Institute of Technology | Chen Zhonglin Z.,Harbin Institute of Technology | Qi F.,Beijing Forestry University | And 2 more authors.
Journal of Hazardous Materials | Year: 2010

N-Nitrosodiethylamine (NDEA) is a member of nitrosamines, which is strong carcinogenic. In order to explore an effective treatment method for NDEA removal from water, sole UV irradiation and UV/O3 were carried out in this study. The removal efficiency, degradation products and pathways were compared between those two processes. Results showed that NDEA removal efficiency achieved 99% within 15min by both UV and UV/O3. Degradation reaction well followed pseudo-first-order kinetics. Water pH had different effect on NDEA degradation in those two processes. Acidic and neutral conditions were good for NDEA degradation by sole UV irradiation. However, NDEA underwent rapid degradation under various pH conditions in the UV/O3 process. Though the ozone introduction in the UV/O3 process had little effect on NDEA degradation efficiency, it had significant effect on its degradation products and pathways. Methylamine, dimethylamine, ethylamine and diethylamine were observed as aliphatic amine products of NDEA degradation in both two processes. They were assumed to arise due to N-N bond fission under UV irradiation, or due to the reaction of NDEA and hydroxyl radicals in the UV/O3 process. © 2010 Elsevier B.V.

Funnell N.P.,University of Oxford | Wang Q.,University of Oxford | Wang Q.,Beijing Forestry University | Connor L.,Diamond Light Source | And 4 more authors.
Nanoscale | Year: 2014

We report the atomic-scale structure of a Zn2Al-borate layered double hydroxide (LDH) nanosheet, as determined by reverse Monte Carlo (RMC) modelling of X-ray total scattering data. This study involves the extension of the RMC method to enable structural refinement of two-dimensional nanomaterials. The refined LDH models show the intra-layer geometry in this highly-exfoliated phase to be consistent with that observed in crystalline analogues, with the reciprocal-space scattering data suggesting a disordered arrangement of the Zn2+ and Al3+ cations within the nanosheet. The approach we develop is generalisable and so offers a method of characterising the structures of arbitrary nanosheet phases, including systems that support complex forms of disorder within the nanosheets themselves. © 2014 the Partner Organisations.

Dai Y.-C.,Beijing Forestry University | Dai Y.-C.,CAS Shenyang Institute of Applied Ecology
Mycoscience | Year: 2011

Corticioid fungi are one of the major groups of wood-inhabiting fungi, and they are mainly confined to the orders Corticiales, Trechisporales and Atheliales among Basidiomycetes. Hydnoid fungi are aphyllophoroid fungi with spine- or tooth-like hymenophore, and most species of them are in the orders of Russulales and Thelephorales. Many hydnoid fungi are wood-inhabiting, but some of them are mycorrhizas. Corticioid fungi and many hydnoid fungi have a similar ecology in forest ecosystems. The current knowledge of corticioid and hydnoid fungi in China is summarized, and totally 506 species are listed alphabetically. A new species, Stereum lithocarpi, is described and illustrated. Two species, Dichostereum boreale and Thanatephorus fusisporus, are new to Chinese fungal flora, and a condensed description of these species is given. © 2010 The Mycological Society of Japan and Springer.

Zhang S.,CAS Academy of Mathematics and Systems Science | Ning X.-M.,Beijing Forestry University | Ding C.,University of Texas at Arlington | Zhang X.-S.,CAS Academy of Mathematics and Systems Science
BMC Systems Biology | Year: 2010

Background: With ever increasing amount of available data on biological networks, modeling and understanding the structure of these large networks is an important problem with profound biological implications. Cellular functions and biochemical events are coordinately carried out by groups of proteins interacting each other in biological modules. Identifying of such modules in protein interaction networks is very important for understanding the structure and function of these fundamental cellular networks. Therefore, developing an effective computational method to uncover biological modules should be highly challenging and indispensable.Results: The purpose of this study is to introduce a new quantitative measure modularity density into the field of biomolecular networks and develop new algorithms for detecting functional modules in protein-protein interaction (PPI) networks. Specifically, we adopt the simulated annealing (SA) to maximize the modularity density and evaluate its efficiency on simulated networks. In order to address the computational complexity of SA procedure, we devise a spectral method for optimizing the index and apply it to a yeast PPI network.Conclusions: Our analysis of detected modules by the present method suggests that most of these modules have well biological significance in context of protein complexes. Comparison with the MCL and the modularity based methods shows the efficiency of our method. © 2010 Zhang et al; licensee BioMed Central Ltd.

Yan Q.L.,CAS Shenyang Institute of Applied Ecology | Zhu J.J.,CAS Shenyang Institute of Applied Ecology | Hu Z.B.,CAS Shenyang Institute of Applied Ecology | Sun O.J.,Beijing Forestry University
Journal of Environmental Quality | Year: 2011

Assessing environmental effects of shelter forests is primarily necessary for realizing their greatest protective benefits. The Three-North Shelter Forest Program (TNSFP), the largest ecological afforestation program in the world, has been operated for three decades in China but so far lacks comprehensive assessment of its environmental impacts. Horqin Sandy Land (HSL) in Northeast China is one of the key areas in the TNSFP implementation. To identify the principal contributors to environmental changes in HSL, we evaluated impacts of variations in landscape features, shelter forest areas, climatic factors, and social factors on changes in sandy land areas from 1978 to 2007, by using Gray Relational Analysis. Our analysis showed that during the period 1978 to 2007, the sandy land area decreased by 3.9% in low aeolian dunes, 14.5% in low mountains and hills, and 98.9% in high elevation alluvial flats of HSL. Factors wiThGray Correlation Degrees >0.9 were identified as the patch shape index (PSI) and the landscape isolation index (LII) of grasses in low aeolian dunes, PSI of grasses in mountains and hills, and area of broadleaved forests and LII of shrubs in alluvial flats. It is concluded that establishment of the shelter forests has played a significant role in controlling the expansion of sandy land in HSL. To sustain the long-term environmental benefits of the shelter forests in the remaining period for TNSFP construction, suitable tree species should be selected and planted at appropriate densities based on the local precipitation, groundwater and landform conditions, and the system stability of the total landscape. © 2011 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Since, 1978, China has pursued some of the world's most ambitious conservation programs, including the Three Norths Shelter Forest System Project, Grain for Green Project, and the Natural Forest Conservation Program. After 30 years of experience with these programs, researchers have found that improving agricultural technology and providing appropriate payment for ecosystem service (PES) to farmers displaced by these programs can improve both the environment and society while avoiding the malignant cycle in which poverty leads to environmental destruction, which then deepens poverty. However, flaws in the implementation of these programs mean that it remains necessary to watch for damage to the environment and society caused by inappropriate technology and policy © Taylor & Francis Group, LLC.

Cao H.,U.S. Department of Agriculture | Cao F.,Beijing Forestry University | Roussel A.-M.,Joseph Fourier University | Anderson R.A.,U.S. Department of Agriculture
In Vitro Cellular and Developmental Biology - Animal | Year: 2013

Quantitative real-time PCR (qPCR) such as TaqMan and SYBR Green qPCR are widely used for gene expression analysis. The drawbacks of SYBR Green assay are that the dye binds to any double-stranded DNA which can generate false-positive signals and that the length of the amplicon affects the intensity of the amplification. Previous results demonstrate that TaqMan assay is more sensitive but generates lower calculated expression levels than SYBR Green assay in quantifying seven mRNAs in tung tree tissues. The objective of this study is to expand the analysis using animal cells. We compared both qPCR assays for quantifying 24 mRNAs including those coding for glucose transporter (Glut) and mRNA-binding protein tristetraprolin (TTP) in mouse 3T3-L1 adipocytes and RAW264.7 macrophages. The results showed that SYBR Green and TaqMan qPCR were reliable for quantitative gene expression in animal cells. This result was supported by validation analysis of Glut and TTP family gene expression. However, SYBR Green qPCR overestimated the expression levels in most of the genes tested. Finally, both qPCR instruments (Bio-Rad's CFX96 real-time system and Applied Biosystems' Prism 7700 real-time PCR instrument) generated similar gene expression profiles in the mouse cells. These results support the conclusion that both qPCR assays (TaqMan and SYBR Green qPCR) and both qPCR instruments (Bio-Rad's CFX96 real-time system and Applied Biosystems' Prism 7700 real-time PCR instrument) are reliable for quantitative gene expression analyses in animal cells but SYBR Green qPCR generally overestimates gene expression levels than TaqMan qPCR. © 2013 The Society for In Vitro Biology.

Liu H.-M.,South China University of Technology | Liu H.-M.,University of South China | Xie X.-A.,University of South China | Ren J.-L.,South China University of Technology | And 2 more authors.
Industrial Crops and Products | Year: 2012

The objective of this work was to develop appropriate reaction pathways to explain the liquefaction behavior of cornstalk in sub- and super-critical ethanol. This reaction system was divided into gas lump, water-soluble oil lump, heavy oil lump, volatile organic compounds lump and residue lump based on the characteristics of cornstalk and liquefaction products, and the residue was further separated into carbon, hydrogen, oxygen and nitrogen. Results showed that the reversible reaction between heavy oil and volatile organic compounds occurred in the liquefaction process, and the decrease in the water-soluble oil yield was mainly attributed to the conversion of water-soluble oil to gas in the sub- and super-critical ethanol. The GC/MS analysis showed that the volatile organic compounds, water-soluble oil and heavy oil comprised a mixture of organic compounds of 6-10, 3-12 and 8-20 carbons, respectively, which mainly included esters, phenols, acids, furans and their derivatives. © 2011 Elsevier B.V.

Shi X.,Beijing Forestry University
Journal of Nonlinear Optical Physics and Materials | Year: 2015

We derive a rigorous quantum formula called topological trajectory to describe orbital angular momentum (OAM) index based on linear momentum density of Laguerre-Gauss (L-G) light beam. By considering the correspondence between optics and quantum theory, we construct a coherent state from two L-G modes light beam. The light beams with fractional OAM are described by the coherent state. By making use of topological trajectory, we present the conditions that OAM index is fractional. © 2015 World Scientific Publishing Company.

The relative effects of climate and geometric constraints on geographic diversity patterns have long been controversial. We developed a new method to assess the role of geometric constraints in shaping altitudinal richness patterns. We showed how plant species richness on four mountains in southwest China are shaped by geometric constraints and environmental gradients together. Contrary to previous studies, our results suggested that: 1) small- and large-ranged species richness were largely controlled by the same environmental gradients, and differed mainly in the effect of geometric constraints. 2) The contribution of geometric constraints (in addition to environmental gradients) to explaining species richness was greater when species richness peaked at low altitudes than at mid-altitudes, suggesting that geometric constraints may be very important when richness peaks are far away from mid-domains. 3) Relating species richness directly to environmental factors (the most widely used method in biodiversity studies) may be misleading when geometric constraints may be affecting the richness pattern, because this method may overestimate the effect of environmental factors by failing to distinguish the confounding effect of geometric constraints. Instead, the effect of environmental factors can be evaluated with an underlying gradient derived from small-ranged species. 4) The geometric constraints effect cannot be fully evaluated by pure geometric constraints models, and is better evaluated with range-based models constrained with environmental gradients. 5) If the generality of our findings is supported for other taxa on other gradients, then many previous studies on the effects of climate and of geometric constraints on geographic diversity patterns may need to be re-visited. © 2012 The Authors. Ecography © 2012 Nordic Society Oikos.

Zhao C.,China Urban Construction Design and Research Institute | Fu G.,CAS Institute of Geographical Sciences and Natural Resources Research | Fu G.,CSIRO | Liu X.,Beijing Forestry University | Fu F.,North China University of Technology
Building and Environment | Year: 2011

Eleven sites, representing different urban morphologies across central Beijing, are used to simulate urban heat island effects and explore the relationship between urban planning indicators and climate indicators such as daily maximum and minimum surface temperatures. The results indicate that mesoscale urban planning indicators can explain the majority of the urban climate differences among the sites. For example, green cover ratio and floor area ratio can explain 94.47-98.57% of the variance for daily maximum surface temperature, green cover ratio and building height can explain 98.94-99.12% of the variance for daily minimum surface temperature, and floor area ratio, green cover ratio and building density together can explain 99.49-99.69% of the variance for time of peak surface temperature. Furthermore, green cover ratio is identified as the most significant urban planning indicator affecting the urban thermal environment. © 2010 Elsevier Ltd.

Dong H.,Harbin Institute of Technology | Guan X.,Tongji University | Wang D.,Harbin Institute of Technology | Li C.,Harbin Institute of Technology | And 2 more authors.
Chemosphere | Year: 2011

Batch experiments were carried out to investigate the influences of H2O2/Fe(II) molar ratio, pH, sequence of pH adjustment, initial As(V) concentration, and interfering ions on As(V) removal in H2O2-Fe(II) process from synthetic acid mine drainage (AMD). The optimum H2O2/Fe(II) molar ratio was one for arsenate removal over the pH range of 4-7. Arsenate removal at pH 3 was poor even at high Fe(II) dosage due to the high solubility of Fe(III) formed in situ. With the increase of Fe(II) dosage, arsenate removal increased progressively before a plateau was reached at pH 5 as arsenate concentration varied from 0.05 to 2.0mgL-1. However, arsenate removal was negligible at Fe/As molar ratio <3 and then experienced a striking increase before a plateau was reached at pH 7 and arsenate concentration ≥1.0mgL-1. The co-occurring ions exerted no significant effect on arsenate removal at pH 5. The experimental results with synthetic AMD revealed that this method is highly selective for arsenate removal and the co-occurring ions either improved arsenate removal or slightly depressed arsenate removal at pH 5-7. The extended X-ray absorption fine structure (EXAFS) derived As-Fe length, 3.27-3.30å, indicated that arsenate was removed by forming bidentate-binuclear complexes with FeO(OH) octahydra. The economic analysis revealed that the cost of the H2O2-Fe(II) process was only 17-32% of that of conventional Fe(III) coagulation process to achieve arsenate concentration below 10μgL-1 in treated solution. The results suggested that the H2O2-Fe(II) process is an efficient, economical, selective and practical method for arsenate removal from AMD. © 2011 Elsevier Ltd.

Yang J.,Tsinghua University | Yang J.,Beijing Forestry University | Gong C.,Tsinghua University | Shi F.-K.,Tsinghua University | Xie X.-M.,Tsinghua University
Journal of Physical Chemistry B | Year: 2012

This investigation was to study the connections between polymer branch architecture of physical hydrogels and their properties. The bottle-brush-like polymer chains of poly(acrylic acid)-g-poly(ethylene glycol) methyl ether (PAA-g-mPEG) with PAA as backbones and mPEG as branch architecture were synthesized and in situ grafted from silica nanoparticles (SNs) to construct hydrogels cross-linked networks in aqueous solutions. The structural variables to be discussed included molecular weight and molar ratio of branch chains, and new aspects of the formation mechanism of physical hydrogels with branch structure in the absence of organic cross-links were present. The results indicated that the differences of polymer chain architecture could be distinguished via their different interactions that are present by gelation process and mature gel properties, such as gel strength and swelling ratio. The gelation occurred at the critical polymer concentration and molecular weight, respectively, and the inorganic/organic (SNs/PAA-g-mPEG) nanoparticles began to entangle and construct the cross-linking networks afterward. The gel-to-sol transition temperature (Tg-s) and radii of SNs that were encapsulated by polymer chains as a function of time for chains' disentanglement were monitored according to the observation of the dissolution process, and the molecular weight between two consecutive entanglements (Me) was calculated thereafter. This study showed that the introduction of branch chain onto the linear backbone significantly promoted the chain interactions and increased entanglement density, which contributed to the hydrogels' network integrity and rigidity, thus illustrating greater elongation at break and tensile strength than the hydrogels formulated with linear polymer chains. © 2012 American Chemical Society.

Song M.-H.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Yu F.-H.,Beijing Forestry University
New Phytologist | Year: 2015

Many ecosystems are facing strong perturbations such as nitrogen (N) fertilization, which can greatly alter ecosystem stability via different mechanisms. Understanding such mechanisms is critical for predicting how ecosystems will function in the face of global changes. We examined how 8 yr of N fertilization with different N rates (no N addition or N addition at a low, medium or high rate) and different forms of N (ammonium, nitrate or ammonium nitrate) affected the temporal stability of the aboveground biomass of an alpine meadow on the Tibetan Plateau, and tested four mechanisms (diversity effect, mean-variance scaling, compensatory dynamics and dominance effect) that may alter stability. Compared with the control (no N addition), a high N rate did not affect the diversity effect, the mean-variance scaling or the dominance effect, but significantly decreased compensatory dynamics among species and functional groups, which contributed to the reduction in community stability of the alpine meadow. The form of N did not affect any of the four mechanisms and thus did not affect community stability. A high N rate can change community stability by altering compensatory dynamics, whereas the form of N may not have an effect © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Ji R.,China Agricultural University | Li D.,China Agricultural University | Chen L.,Beijing Forestry University | Yang W.,China Agricultural University
Mathematical and Computer Modelling | Year: 2010

Foreign fibers in cotton have seriously affected the quality of cotton products. The classification and identification of foreign fibers in cotton is the foundation of cotton foreign fiber automated inspection. The paper takes the typical cotton foreign fibers in China's textile enterprises as the research object, and acquires the images under simulated actual cotton processing. The various classification features are calculated and analyzed. The results show that aspect ratio, roundness, duty cycle and I 1 are the effective features for classifying various foreign fibers. The paper puts forward a classifier of cotton foreign fibers based on a support vector machine. A Decision Tree Support Vector Machine (DTSVM) can not only avoid the non-separated region, but also improve the training speed while the training sample number gradually decreases, going through the decision tree. The DTSVM is to be used to identify the sorts of common foreign fibers in cotton. The experimental data set shows that the rates of identifying different kinds of foreign fibers are greater than 92% using the proposed DTSVM. © 2009.

Li F.,Beijing Forestry University | Yin Y.,East China Institute of Technology
Information Sciences | Year: 2012

In this paper, we consider a semigroup as a universal set and investigate the properties of v-lower and T-upper fuzzy rough approximation operators. A new fuzzy algebraic structure, called a TL-fuzzy rough semigroup, is introduced and some related properties are studied. Finally, the homomorphism properties of -lower and T-upper fuzzy rough approximation operators are investigated. © 2012 Elsevier Inc. All rights reserved.

Zhou L.-W.,CAS Shenyang Institute of Applied Ecology | Dai Y.-C.,CAS Shenyang Institute of Applied Ecology | Dai Y.-C.,Beijing Forestry University
Mycologia | Year: 2013

The phylogeny of taxa with poroid and lamellate hymenophores in Auriculariales as yet has not been well studied. Here we sequenced the nLSU and ITS regions of poroid and lamellate representatives from the genera Elmerina, Protodaedalea and Protomerulius to establish the phylogenetic position of these morphologically similar taxa. Our analyses suggest that (i) Elmerina foliacea is divergent from all other Elmerina species sampled; (ii) Protodaedalea hispida (the type of monotypic genus Protodaedalea) and Protomerulius efibulatus should be transferred to Elmerina as E. hispida and E. efibulata respectively; (iii) after exclusion of P. efibulatus, Protomerulius becomes monophyletic and represents the core of a "Protomerulius family" clade that potentially includes species from Tremellodendropsis, Heterochaetella and Protodontia; and (iv) the presence or absence of gloeocystidia serves as the most reliable morphological feature in delimiting Elmerina s.l. and Protomerulius. Concepts of Elmerina s.l. and Protomerulius are redefined, and diagnostic keys for these two genera are provided. © 2013 by The Mycological Society of America.

Peat mined from endangered wetland ecosystems is generally used as a component in soilless potting media in horticulture but is a costly and non-renewable natural resource. The objective of this work was to study the feasibility of replacing peat with different percentages (0, 10, 30, 50, 70, 90, and 100%) of composted green waste (CGW) as growth media for the production of the ornamental plant Calathea insignis. Compared with 100% peat media, media containing CGW had improved physical and chemical characteristics to achieve the acceptable ranges. Moreover, CGW addition had increased the stability (i.e., reduced the decomposition rates) of growth media mixtures, as indicated by comparison of particle-size distribution at the start and end of a 7-month greenhouse experiment. Addition of CGW also supported increased plant growth (biomass production, root morphology, nutrient contents, and photosynthetic pigment contents). The physical and chemical characteristics of growth media and plant growth were best with a medium containing 70% CGW and were better in a medium with 100% CGW than in one with 100% peat media. These results indicate that CGW is a viable alternative to peat for the cultivation of Calathea insignis.

Chen H.,Beijing Forestry University | Zhang T.,Beijing Institute of Technology | Zhang J.,Beijing Institute of Technology
Structural Chemistry | Year: 2012

A novel 5-aminotetrazole mixed ligands complex of formula [Cu(PTS) 2(ATZ) 2(H 2O) 2] (C 16H 24CuN 10O 8S 2, PTS = p-toluenesulfonate, ATZ = 5-aminotetrazole) has been obtained by the reaction of 5-aminotetrazole with copper acetate and p-toluenesulfonic acid on heating in water. It was characterized by elemental analysis, FT-IR spectroscopy, and X-ray single crystal diffraction. The compound crystallizes in monoclinic system, space group P2 1/c, Z = 2, a = 14.079(4) Å , b = 6.088(3) Å , c = 14.632(4) Å , β = 105.268(4)°, V = 1209.8(5) Å 3. The central copper(II) cation is coordinated by two N atoms and four O atoms from two ATZ ligands, two water molecules and two p-toluenesulfonate ions to form a six-coordinated and distorted octahedral structure. Neutral ATZ is coordinated in the monodentate mode by the N(4) atom. The sulfonate group of the PTS ligand remains weak-coordinated modes and forms a number of hydrogen bonds with water molecule ligands and ATZ ligands. A supramolecular framework is connected by electrostatic interaction, weak coordinated bonding, hydrogen-bonding, and p-p interaction. The thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG, and FT-IR analyses. Thermolysis of ATZ and its several derivatives is compared. © Springer Science+Business Media, LLC 2011.

Xu X.,Beijing Forestry University | Luo J.,Tsinghua University | Guo D.,Tsinghua University
Soft Matter | Year: 2012

The deposit pattern of drying liquid droplets has a close relationship with the radial-velocity profile along the droplet surface. In this paper, the surface temperature of the droplet is first solved numerically and approximated by a simple analytical form, and an analytical expression for the radial-velocity of the surface flow is then obtained by using the lubrication analysis developed by Hu and Larson. The theoretical analysis indicates that the outward surface flow will be reduced by the thermal Marangoni stress along the surface. When the Marangoni number is below a critical value, MaCrit, all the surface liquid will move outward and a dense, ring-like deposit will be formed. When above MaCrit, a stagnation point, within which the surface flow is inward and beyond which the surface flow is outward, will appear on the droplet surface. In such case, the particles transported to the surface beyond the stagnation point will move to the droplet edge to form the ring deposit, and the others will deposit on the central region of the droplet. Numerical results indicate that the critical Marangoni number decreases in a power law with the contact angle. The theory for the radial-velocity of the surface flow will be helpful to predict and control the deposit patterns from the drying droplets. © 2012 The Royal Society of Chemistry.

Dong M.,Beijing Forestry University
Advance Journal of Food Science and Technology | Year: 2015

This study, based on the economic development of modern forestry management, finds out the degree of adaptation of the sustainable development model in forestry economy and therefore helps the forestry industry to achieve a scientific and comprehensive development model. © Maxwell Scientific Organization, 2015.

Chen C.,Helmholtz Center for Environmental Research | Hagemann S.,Max Planck Institute for Meteorology | Liu J.,Beijing Forestry University | Liu J.,International Institute For Applied Systems Analysis
Environmental Earth Sciences | Year: 2014

Climate change as a result of the increased greenhouse gas emissions may influence the availability of water resources in many regions on the globe. In the past decades, China has been facing severe shortage of water resources. This study focuses on the assessment of the impact of climate change on both blue and green water resources in ten large river basins in China. The blue and green water resources for these river basins were derived from the terrestrial hydrological fluxes in period 1960–2100, which were simulated with the Max Planck Institute Hydrological Model—MPI-HM. The forcing data for the hydrological model, the precipitation and temperature were obtained from three coupled Atmosphere–Ocean General Circulation Models (GCMs)—ECHAM5, IPSL and CNRM, under A2 and B1 greenhouse gas emission scenarios. The statistical bias correction method was applied on the output from the three GCMs. By using this climate model–hydrology model modeling chain, the impact of climate change on the blue and green water resources was analyzed over the ten Chinese river basins. Here, the projected changes in 2071–2100 are considered relative to 1971–2000. The projected change of monthly mean and annual mean of green water resources show the general increase for all ten river basins; among them, Inland river, Zhemin river and Zhujiang river have larger change signal than other basins. For blue water resources, increases of the annual mean are projected from November to March for Heilongjiang river, Liaohe river and Yellow river, Inland river in Northern China; and decreases are projected for Huaihe river, Zhemin river, Haihe river, Yangzi river, Southwest river, and Zhujiang river basins in Southern China. It is found that climate change has impact on both blue and green water resources over large river basins in China. The sustainable blue water resources management should take into account the different changes in both Northern and Southern China. The results show that a better management of green water resources is of importance for food and ecological securities in the context of global change. © 2014 Springer-Verlag Berlin Heidelberg

Chen C.,University of Oxford | Yang M.,University of Oxford | Wang Q.,Beijing Forestry University | Buffet J.-C.,University of Oxford | O'Hare D.,University of Oxford
Journal of Materials Chemistry A | Year: 2014

We report the synthesis and characterisation of a new family of layered double hydroxides entitled Aqueous Miscible Organic Layered Double Hydroxide (AMO-LDH). AMO-LDHs have the chemical composition [Mz+ 1-xM′y+ x(OH)2] a+(Xn-)a/r·bH2O·c(AMO- solvent) wherein M and M′ are metal cations, z = 1 or 2; y = 3 or 4, 0 < x < 1, b = 0-10, c = 0-10, X is an anion, r is 1-3 and a = z(1 - x) + xy - 2. The role of the AMO-solvents such as acetone (A) or methanol (M) in the LDH synthesis is discussed. The distinguishing features between AMO, and conventional or commercial LDHs are investigated using X-ray diffraction, infrared spectroscopy, electron microscopy, thermal analysis, adsorption and powder density studies. These experiments show that AMO-LDHs are highly dispersed and exhibit significantly higher surface areas and lower powder densities than conventional or commercially available LDHs. AMO-LDHs can exhibit N2 BET surface areas in excess of 301 m2 g-1 compared to 13 m2 g-1 for the equivalent LDHs prepared by co-precipitation in water. The Zn2Al-borate LDH exhibits a pore volume of 2.15 cm3 g-1 which is 2534 times higher than the equivalent conventionally prepared LDH. © the Partner Organisations 2014.

Xu S.,Chinese Institute of Scientific and Technical Information | An X.,Beijing Forestry University | Zhu L.,Chinese Institute of Scientific and Technical Information | Zhang Y.,Chinese Institute of Scientific and Technical Information | Zhang H.,Network Center
Journal of Cheminformatics | Year: 2015

Background: In order to improve information access on chemical compounds and drugs (chemical entities) described in text repositories, it is very crucial to be able to identify chemical entity mentions (CEMs) automatically within text. The CHEMDNER challenge in BioCreative IV was specially designed to promote the implementation of corresponding systems that are able to detect mentions of chemical compounds and drugs, which has two subtasks: CDI (Chemical Document Indexing) and CEM. Results: Our system processing pipeline consists of three major components: pre-processing (sentence detection, tokenization), recognition (CRF-based approach), and post-processing (rule-based approach and format conversion). In our post-challenge system, the cost parameter in CRF model was optimized by 10-fold cross validation with grid search, and word representations feature induced by Brown clustering method was introduced. For the CEM subtask, our official runs were ranked in top position by obtaining maximum 88.79% precision, 69.08% recall and 77.70% balanced F-measure, which were improved further to 88.43% precision, 76.48% recall and 82.02% balanced F-measure in our post-challenge system. Conclusions: In our system, instead of extracting a CEM as a whole, we regarded it as a sequence labeling problem. Though our current system has much room for improvement, our system is valuable in showing that the performance in term of balanced F-measure can be improved largely by utilizing large amounts of relatively inexpensive un-annotated PubMed abstracts and optimizing the cost parameter in CRF model. From our practice and lessons, if one directly utilizes some open-source natural language processing (NLP) toolkits, such as OpenNLP, Standford CoreNLP, false positive (FP) rate may be very high. It is better to develop some additional rules to minimize the FP rate if one does not want to re-train the related models. Our CEM recognition system is available at: http://www.SciTeMiner.org/XuShuo/Demo/CEM. Copyright © 2015 Xu et al.

Huang Y.,Beijing Forestry University
Journal of Wood Science | Year: 2016

Load and moisture content (MC) changes are the essential conditions for the mechano-sorptive (MS) creep of wood. An experiment was carried out on poplar to comprehend the mechano-sorptive creep from our point view. To restore the truth of MS creep behavior especially in the first humidifying stage, three well-matched sets of specimens were loaded in third-point bending under different humidity cycles. For each set, the applied load varied from 15 to 35 % of the short-term breaking load. It was found that the wood specimens exhibited a partial recovery during all the adsorption phase and deflection increase during all the desorption phase when low load level was applied. This phenomenon was very different from that a considerable creep at first adsorption observed by large amounts of researchers, which can be ascribed to the pseudo-creep due to the difference in the normal longitudinal swelling and shrinkage of wood. The results also indicated that an amplified load effect existed within the creep under cyclic moisture changes, which usually resulted in a fast increasing rate of viscoelastic creep to veil pseudo-recovery in the first humidifying stage. © 2016 The Japan Wood Research Society

Vainio E.J.,Finnish Forest Research Institute | Hakanpaa J.,Finnish Forest Research Institute | Dai Y.-C.,Beijing Forestry University | Hansen E.,Oregon State University | And 2 more authors.
Fungal Biology | Year: 2011

We investigated the geographic occurrence and genetic diversity of partitiviruses among 247 Heterobasidion specimens representing seven species and originating from Europe, Asia, and North America. Based on sequence analysis, partitiviruses were relatively rare, and occurred only in about 5 % of the Heterobasidion isolates analyzed, constituting a minority (about 28 %) of all virus-infected [double-stranded RNA (dsRNA)-positive] isolates. Altogether ten virus strains were characterized in sequence: one complete genome sequence of 3893 bp, six complete RNA-dependent RNA polymerase sequences of 2000-2033 bp, and three partial polymerase sequences. Based on phylogenetic analysis, the virus strains were assigned into three putative partitivirus species: HetRV1 (Heterobasidion RNA virus 1), HetRV4, and HetRV5. Degenerate consensus primers were designed for RT-PCR detection of these virus species. HetRV1 occurred in five different Heterobasidion species, and resembled the previously described Heterobasidion annosum virus (HaV). Highly similar HetRV1 strains with 98 % nucleotide level similarity were found from H. parviporum (member of the H. annosum species complex) and H. australe (member of the H. insulare complex) growing in the same region in Bhutan. This observation suggests recent virus transmission between these taxonomically distant Heterobasidion species in nature. It was also shown that HetRV1 can be transmitted by mycelial contact between the H. annosum and H. insulare complexes. The two other virus species, HetRV4 and HetRV5, were closely related to the Amasya Cherry Disease-associated mycovirus, to Heterobasidion parviporum partitivirus Fr110B, and also to several plant-infecting alphacryptoviruses. These results are in accordance with the view of a close evolutionary relationship between partitiviruses of plants and fungi. © 2011 British Mycological Society.

Johnson M.H.,Urbana University | De Mejia E.G.,Urbana University | Fan J.,Beijing Forestry University | Lila M.A.,North Carolina State University | Yousef G.G.,North Carolina State University
Molecular Nutrition and Food Research | Year: 2013

Scope: Berries are an excellent source of dietary flavonoids which have several health benefits. Methods and results: We evaluated well-characterized anthocyanins (ANCs) and proanthocyanidins (PACs) from fermented blueberry-blackberry beverages. Wines were produced from highbush blueberries and blackberries grown in Illinois and blended to create ratios ranging from 100% blueberry to 100% blackberry. Total ANCs of the wine were strongly correlated to total phenolics (r = 0.99, p < 0.05) and to antioxidant capacity (r = 0.77, p < 0.05). ANC- and PAC-enriched fractions were purified from each wine blend and a phenolic profile was generated. ANCs increased with more blackberries from 1114 to 1550 mg cyanidin-3-O-glucoside (C3G) equivalents/L. Hydrolysable tannins were identified in the PAC-enriched fraction. Both ANC- and PAC-enriched fractions inhibited starch-degrading enzyme α-glucosidase and dipeptidyl peptidase-IV activity. Computational docking demonstrated that delphinidin-3-arabinoside effectively inactivated dipeptidyl peptidase-IV by binding with the lowest interaction energy (-3228 kcal/mol). ANC and PAC (100 μM C3G and epicatechin equivalents, respectively) from blueberry-blackberry blends reduced LPS-induced inflammatory response in mouse macrophages via the nuclear factor kappa B-mediated pathway. Conclusion: ANC- and PAC- (including hydrolysable tannins in blackberry) enriched fractions from blueberry and blackberry fermented beverages are beneficial sources of antioxidants, inhibitors of carbohydrate-utilizing enzymes, and potential inhibitors of inflammation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wu H.,Hainan University | Song X.,Hainan University | Liu H.,Beijing Forestry University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Dendrobium catenatum is a perennial, epiphytic orchid. It is not only an ornamental plant, but also an invaluable medicinal herb in China. It has the functions of benefiting the stomach and spleen, nourishing Yin and kidney, moistening the lungs, promoting the production of body fluid and improving immunity. Natural seed set is low and the wild resource of D. catenatum is scare. In recent decades, D. catenatum had been over-collected for its high profits, which led to drastic reduction of the wild populations of D. catenatum. In addition, D. catenatum's habitats were severely degraded. Together, these factors have driven D. catenatum to the verge of extinction. There is mature tissue culture technology of D. catenatum, but the survival rate of sterile plants in tissue culture is low, seedling growth rate is slow, and large scale production is difficult. Therefore, it's very important to protect the wild resources and habitats of D. catenatum. Effective ex-situ propagation of the species may help to boost the wild populations. It is well known that mycorrhizal fungi play an important role in the germination, growth and development of orchids, and understanding the relationship between orchids and mycorrhizae is important for the conservation of orchids. Our aim is to find the symbiotic fungi which can promote seed germination and production of symbiotic seedlings, and use them in the artificial cultivation and reintroduction. We used seeds (with seed viability of 77. 65% based on TTC staining) harvested from wild plants of D. catenatum in Hunan province, and inoculated them with four symbiotic fungi that were isolated from the roots of D. catenatum (C20) and D. loddigessi (L12, L24b and L28) respectively in petri dishes with oat meal agar. Seed germination and protocorm development were observed using Dino-Litle Digital-Microscope and Olympus Microscope once a week. After 18-weeks cultivation, all four symbiotic fungi promoted germination of D. catenatum seeds, but to various degrees. Specifically, seeds co-cultured with strains L24b (Epulorhiza) and L28 (Epulorhiza) had a significantly higher germination rates (88 41% and 74. 10%, respectively) than that of the control(61. 90%), but they were not able to form seedlings and were developed only to the stage of protomeristem (stage 3). Strains C20 (Epulorhiza) and L12 (Alternaria) did not significantly improve seed germination rate compared with control treatment. However, they promoted seeds to form symbiotic seedlings. During the same period of time, seeds in the control treatment were still in the stage of embryo enlargement with ruptured testa(= germination, stage 2). TTC staining showed that the seed viability is higher than the germination rate of symbiotic seed germination (excepted for strain L24b). Our study suggested that seed viability staining only represent the potential of germination instead of the real germination rate. The specificity between symbiotic fungi and D. catenatum is low in vitro because seeds of D. catenatum can form symbiosis between the fungi of Epulorhiza and Alternaria, and these two strains were from different orchids. Strains C20 and L12 may be used for high quality artificial cultivation as well as restoration of wild populations of D. catenatum.

Wang X.,South China University of Technology | Guo Y.,South China University of Technology | Li D.,South China University of Technology | Chen H.,South China University of Technology | And 2 more authors.
Chemical Communications | Year: 2012

A novel fluorescent amphiphilic cellulose nanoaggregates sensing system is designed and applied in detecting explosives in aqueous solution. Due to the maximized interaction between sensing material and analyte within the cellulose-based nanoaggregates, significantly enhanced sensitivity with 50-fold higher quenching efficiency is obtained. © 2012 The Royal Society of Chemistry.

Liang K.,University of North Texas | Gao Q.,University of North Texas | Gao Q.,Beijing Forestry University | Shi S.Q.,University of North Texas
Journal of Applied Polymer Science | Year: 2013

In this research, three different types of biocomposites were made from kenaf fiber/soy protein, kenaf fiber/DS 3530, and kenaf fiber/soy protein/DS 3530. Fourier transform infrared spectra of the biocomposites showed that there were chemical reactions among the kenaf fiber, soy flour, and BASF Acrodur resin. The hot-pressing time had a significant effect on the flexural properties and density of both the kenaf fiber/soy flour composites and kenaf fiber/BASF Acrodur resin composites. However, the effect was opposite for the composites from 10 to 20 min of hot pressing. As the hot-pressing time increased, the flexural properties and density increased for the kenaf fiber/soy flour composites and decreased for the other two composites with BASF Acrodur resin. BASF Acrodur resin reduced the hot-pressing time of the biocomposites. With 28 wt % BASF Acrodur resin (on the basis of 100% solid content) as a binder and with the biocomposites hot-pressed for 10 min, the swelling thickness and water absorption of the composites were reduced by 55 and 64%, and the flexural strength and modulus were improved by 72 and 188%, respectively. More simultaneous failures of the fiber and adhesive were observed at the fracture surface of the kenaf fiber/soy flour/BASF Acrodur resin composite. © 2012 Wiley Periodicals, Inc.

Tengberg A.,Gothenburg University | Zhang K.,Beijing Forestry University
Land Degradation and Development | Year: 2014

The People's Republic of China-Global Environment Facility Partnership to Combat Land Degradation in Dryland Ecosystems promotes an integrated ecosystem management (IEM) approach to restore, sustain and enhance the productive capacity of dryland ecosystems. This paper provides an analysis and synthesis of the funding strategies, methods and approaches that have been applied and tested under the Partnership to pilot and scale up IEM and sustainable land management (SLM) practices in the western People's Republic of China under its first 10years. On the basis of a mix of methods using literature reviews, data collection at selected pilot sites through household questionnaire surveys, stakeholder workshops and field sampling, the following lessons were generated: (i) mainstreaming of IEM into relevant policy and development frameworks has been the most effective way of mobilizing funding for scaling up of SLM; (ii) SLM best practices need to be combined with economic incentives for land users, and pilot demonstrations of SLM need to be integrated into larger investment programmes to achieve impacts and economies of scale; (iii) market-based approaches to scaling up of SLM, such as payment for ecosystem services and public-private partnerships, have a role to play, but cost-benefit analysis need to be better integrated into payment schemes; (iv) the economic benefits of carbon sequestration are too low to fund eco-compensation schemes on their own but can provide supplementary funding; and (v) land degradation and SLM monitoring and assessment systems should be multiscale to support decision-making on SLM and to monitor impact from the local to the national level. © 2013 John Wiley & Sons, Ltd.

Liu B.,South China University of Technology | Wang X.,South China University of Technology | Yang B.,CAS Guangzhou Institute of Geochemistry | Sun R.,South China University of Technology | Sun R.,Beijing Forestry University
Materials Chemistry and Physics | Year: 2011

A rapid method was developed to prepare organic montmorillonite (organo-MMT) using three novel Gemini surfactants by microwave irradiation of 1 h, which was more effective than conventional heating method of 8-48 h. The structure and morphology of organo-MMTs were characterized by XRD, FT-IR, TEM and SEM. The adsorption amount of Gemini surfactants on MMT and the thermal stability of organo-MMTs were investigated by thermogravimetric analysis (TGA). The results indicated that Gemini surfactants were more efficient than cetyltrimethyl ammonium bromide in the modification of MMT, the organoclays obtained by microwave irradiation method had larger layer spacing than those from traditional heating method. And with the increase of the dosage and chain length of Gemini surfactants, the amount of the intercalary or adsorbed surfactant on the organoclay gradually increased, whereas the thermal stability weakened appropriately. Besides, the adsorption results for methyl orange indicated that all organo-MMTs displayed more excellent adsorption capacities than unmodified MMT. The amount of methyl orange adsorbed onto the organo-MMTs increased proportionately with the increase of the amount or the chain length of Gemini surfactants. This study affords a rapid and efficient method to obtain the organoclay with large interlayer distance and strong adsorption capacity. © 2011 Elsevier B.V. All rights reserved.

Huang H.,Beijing Forestry University | Huang H.,Virginia Polytechnic Institute and State University | Wynne R.H.,Virginia Polytechnic Institute and State University
Canadian Journal of Remote Sensing | Year: 2013

Our objective was to assess the effect of multiple scattering on lidar radiative transfer. We have developed a time-dependent radiosity-based model (RBL) to simulate the propagation of lidar pulses through forest canopies. This 3-D model enables simulation of lidar waveforms with varied topography and clumping vegetation. The incidence angle can also be specified. This new model has the potential to provide better approximations of return waveforms. The prototype is being tested using data from the Scanning Lidar Imager of Canopies by Echo Recovery (SLICER). Waveforms simulated by RBL resemble SLICER waveforms (R2 > 0.90) over a jack pine canopy and a black spruce canopy. There is also good agreement (R2 > 0.95) when the model results are compared with a time-dependent radiative transfer model. Results to date indicate that multiply scattered photons do increase the intensity of the reflected signal, especially the portion originating from the lower levels of the canopy. A sensitivity analysis enabled assessment of the effects of leaf area index, slope, and canopy height on multiple scattering. © 2013 CASI.

Wang L.,Harbin Institute of Technology | Ma F.,Harbin Institute of Technology | Qu Y.,Dalian University of Technology | Sun D.,Beijing Forestry University | And 3 more authors.
World Journal of Microbiology and Biotechnology | Year: 2011

A compound bioflocculant CBF-F26, produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its physicochemical and flocculating properties. It was identified as a polysaccharide bioflocculant composed of rhamnose, mannose, glucose, and galactose, respectively, in a 1. 3: 2. 1: 10. 0: 1. 0 molar ratio. The average molecular weight was determined as 4. 79 × 105 Da by gel-permeation chromatography. Infrared spectrum and X-ray photoelectron spectroscopy revealed the presence of carboxyl, hydroxyl and amino groups in its structure. Thermostability test suggested that CBF-F26 was thermostable and high flocculating activity was maintained. Thermogravimetric property, intrinsic viscosity and surface morphology of CBF-F26 were also studied. CBF-F26 was effective under neutral and weak alkaline conditions (pH 7. 0-9. 0), and flocculating activities of higher than 90% were obtained in the concentration range of 8-24 mg l-1 at pH 8. 0. The flocculation could be stimulated by cations Ca2+, Zn2+, Fe2+, Al3+, and Fe3+. In addition, the probable flocculation mechanisms were proposed. © 2011 Springer Science+Business Media B.V.

You W.,Beihang University | You W.,Beijing Forestry University | Liu L.,Beihang University | Xia M.,Santa Clara University | Lv C.,Beihang University
Electronic Commerce Research and Applications | Year: 2011

In consumer-to-consumer (C2C) markets, sellers can manipulate their reputation by employing a large number of puppet buyers who offer positive feedback on fake transactions. We present a conceptual framework to identify the characteristics of collusive transactions based on the homo economicus assumption. We hypothesize that transaction-related indicators including price, frequency, comment, and connectedness to the transaction network, and individual-related indicators including reputation and age can be used to identify collusive transactions. The model is empirically tested using a dataset from Taobao, the largest C2C market in China. The results show that the proposed indicators are effective in identifying collusive traders. © 2011 Elsevier B.V. All rights reserved.

Gao D.X.,Beijing Forestry University | Sun Z.Q.,Tsinghua University
Science China Information Sciences | Year: 2011

The main focus of this paper is on designing a T-S fuzzy controller for the hypersonic vehicle. The longitudinal dynamics of the vehicle are studied using time-scale decomposition to reduce the complexity of T-S modeling. The dynamic inversion with PI control technique is applied for the slow dynamics to derive the flight path angle command and throttle setting by taking the pilot altitude and velocity command as its inputs. The T-S fuzzy controller is designed for the fast dynamics to derive the elevator deflection to track the flight path angle command. The discrepancy between the T-S model and real vehicle model is considered by using sliding mode control for the system stability. Simulation results are included to show the effectiveness of the controller. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.

Chen S.,Beijing Forestry University | Diekmann H.,University of Gottingen | Janz D.,University of Gottingen | Polle A.,University of Gottingen
Materials | Year: 2014

Energy-dispersive X-ray microanalysis (EDX) is a technique for determining the distribution of elements in various materials. Here, we report a protocol for high-spatial-resolution X-ray elemental imaging and quantification in plant tissues at subcellular levels with a scanning transmission electron microscope (STEM). Calibration standards were established by producing agar blocks loaded with increasing KCl or NaCl concentrations. TEM-EDX images showed that the salts were evenly distributed in the agar matrix, but tended to aggregate at high concentrations. The mean intensities of K+, Cl-, and Na+ derived from elemental images were linearly correlated to the concentrations of these elements in the agar, over the entire concentration range tested (R > 0.916). We applied this method to plant root tissues. X-ray images were acquired at an actual resolution of 50 nm × 50 nm to 100 nm × 100 nm. We found that cell walls exhibited higher elemental concentrations than vacuoles. Plants exposed to salt stress showed dramatic accumulation of Na+ and Cl- in the transport tissues, and reached levels similar to those applied in the external solution (300 mM). The advantage of TEM-EDX mapping was the high-spatial-resolution achieved for imaging elemental distributions in a particular area with simultaneous quantitative analyses of multiple target elements. © 2014 by the authors.

Peng Y.,Beijing Forestry University | Huang X.,Communication University of China
ICIC Express Letters, Part B: Applications | Year: 2016

In this paper we study the joint optimization of Gaussian mixture model parameters in speaker identification. First, we introduce the baseline speaker identification system. Second, we study the feature optimization and we simplify the transform matrix into a feature selection vector in speaker identification. Third, The joint estimation of the parameters is proposed based on the shuffled frog leaping algorithm. The traditional expectation-maximization algorithm is embedded in the proposed algorithm. The experimental results show that the proposed optimization framework is effective and achieved a constant improvement in speaker identification. © 2016 ICIC International.

Zhang T.,CAS Institute of Atmospheric Physics | Wang H.,Beijing Forestry University
PLoS ONE | Year: 2015

We identified the spatiotemporal patterns of the Normalized Difference Vegetation Index (NDVI) for the years 1982-2008 in the desert areas of Northwest China and quantified the impacts of climate and non-climate factors on NDVI changes. The results indicate that although the mean NDVI has improved in 24.7% of the study region; 16.3% among the region has been stagnating in recent years and only 8.4% had a significantly increasing trend. Additionally, 45.3% of the region has maintained a stable trend over the study period and 30.0% has declined. A multiple regression model suggests that a wetter climate (quantified by the Palmer Drought Severity Index, PDSI) is associated with higher NDVI in most areas (18.1% of significance) but these historical changes in PDSI only caused an average improvement of approximately 0.4% over the study region. Contrasting the regression results under different trend patterns, no significant differences in PDSI impacts were detected among the four trend patterns. Therefore, we conclude that climate is not the primary driver for vegetative coverage in Northwest China. Future studies will be required to identify the impacts of specific non-climatic factors on vegetative coverage based on high-resolution data, which will be beneficial in creating an effective strategy to combat the recent desertification trend in China. © 2015 Zhang, Wang. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Pu J.,Beijing Forestry University
Wood and Fiber Science | Year: 2014

In this study, methylolurea and polyacrylic resin were used to modify fast-grown poplar. The dimensional stability and mechanical properties of natural and modified wood were investigated. Also, the modified samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results showed that the chemical modifier was impregnated into the wood inner structure, which improved the chemical and mechanical performance of wood. FTIR demonstrated that the hydroxyl groups of wood were decreased, which decreased the water absorption of natural wood. XRD tests indicated that the crystallinity of wood increased but the structure of cellulose was not disrupted after modification. TGA analysis showed that the thermal stability of the hemicelluloses and cellulose was enhanced after modification. The prepolymer was not only impregnated into the wood cell, but also reacted with the wood fiber. A crosslinking reaction occurred between the wood modifier and wood fiber. © 2014 by the Society of Wood Science and Technology.

Wen Y.-Q.,China Agricultural University | He F.,China Agricultural University | Zhu B.-Q.,Beijing Forestry University | Lan Y.-B.,China Agricultural University | And 5 more authors.
Food Chemistry | Year: 2014

This paper reports the occurrence of both free and glycosidically bound aroma compounds in three sweet cherry cultivars ('Hongdeng', 'Hongyan' and 'Rainier'), with 97 compounds being identified in the three cultivars. The major free volatile compounds found were hexanal, (E)-2-hexenal, (E)-2-hexen-1-ol, benzyl alcohol and benzaldehyde. The major bound volatile compounds found were benzyl alcohol, geraniol, 2-phenylethanol. Also 4-vinylphenol was found in cherry fruit for the first time, and has a relatively high concentration of the glycosidically-bound form in 'Rainier'. Odour activity values (OAVs) were determined for both free and bound volatiles, with 18 compounds having an OAV above 1. The highest OAVs for three cultivars were (E)-β-ionone, hexanal, decanal and (E)-2-hexenal with the highest being over 800 for (E)-β-ionone in 'Honyang'. From these results, it was concluded that the aroma compounds present were similar in all three cultivars, but there was significant variation found in their levels and hence contribution to the aroma of these cultivars. © 2013 Elsevier Ltd. All rights reserved.

Yang J.,Tsinghua University | Yang J.,Beijing Forestry University | Wang X.-P.,Tsinghua University | Xie X.-M.,Tsinghua University
Soft Matter | Year: 2012

This paper introduces a versatile method to synthesize physical hydrogels by silica nanoparticle (SN) surface in situ polymerization. A series of poly(acrylic acid) chains were covalently grafted from the SNs that were treated with γ-methacryloxypropyl trimethoxy silane. The entanglements among the grafted chains constructed the hydrogel networks and the SNs played the role of 'analogous crosslinking points'. The SNs were encapsulated by the grafted polymer chains and formed a 'core-shell' structure. It was found that the molecular weight of the grafted chains and the content and diameter of the SNs affected the hydrogel's properties. In comparison with chemically crosslinked hydrogels, the hybrid hydrogels exhibited excellent mechanical properties and could endure stress as high as 3.16 MPa and an elongation of 440% at a water content of 100 wt%. The gel-sol phenomenon confirmed that this hybrid hydrogel belonged to the physically crosslinked type. © 2012 The Royal Society of Chemistry.

Ning X.,Beijing Forestry University | Liu Z.,CAS Academy of Mathematics and Systems Science | Zhang S.,CAS Academy of Mathematics and Systems Science
Physica A: Statistical Mechanics and its Applications | Year: 2016

Network is a simple but powerful representation of real-world complex systems. Network community analysis has become an invaluable tool to explore and reveal the internal organization of nodes. However, only a few methods were directly designed for community-detection in directed networks. In this article, we introduce the concept of local community structure in directed networks and provide a generic criterion to describe a local community with two properties. We further propose a stochastic optimization algorithm to rapidly detect a local community, which allows for uncovering the directional modular characteristics in directed networks. Numerical results show that the proposed method can resolve detailed local communities with directional information and provide more structural characteristics of directed networks thprevious methods. © 2016 Elsevier B.V. All rights reserved.

Zhong L.-X.,South China University of Technology | Peng X.-W.,South China University of Technology | Yang D.,South China University of Technology | Cao X.-F.,South China University of Technology | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2013

Xylan, which is a widely abundant plant polymer, has been considered as an alternative for film preparation. Up to now, however, xylan films have suffered from brittleness, low mechanical strength, and humidity sensitivity. This paper describes a new and effective strategy to prepare xylan films with high mechanical strength and less moisture-sensitive properties by introducing long carbon chains into the xylan backbone. Furthermore, this work revealed some important details on the relationships between structure (molecular structure, aggregation behaviors, and surface morphology) and properties (film-forming performance, flexibility, tensile strength, and hydrophilicity) of xylan film. It was found that the hydrophobic carbon chains (2-octenylsuccinic anhydride half-ester groups) in the xylan backbone acted as steric hindrance and could effectively prevent xylan chains from aggregation. 2-Octenylsuccinic anhydride (2-OSA) modified xylan (2-OSA-X) demonstrated amorphous structure and had better film-forming performance than the unmodified xylan. 2-OSA-X films were smooth, flexible, and less moisture-sensitive and showed significantly increasing tensile strength at a low degree of substitution. © 2012 American Chemical Society.

Zhao G.,Beijing Forestry University
Wood and Fiber Science | Year: 2014

Preoxidation treatments in air at 200-280°C were introduced in the preparation of activated carbon fiber from liquefied wood (LWACF) with steam activation at 910°C to enlarge its pore size distribution (PSD). LWACF yield was improved 1.14 times with preoxidation at 200°C. With increasing preoxidation temperature, the specific surface area increased from 2592 to 3068 m2/g. Preoxidations at 200 and 240°C predominantly enhanced the microporosity development without significant pore widening, whereas preoxidation at 280°C significantly enlarged the PSD. Mesopore volume increased by 72%, and methylene blue adsorption capacity improved by 34%. © 2014 by the Society of Wood Science and Technology.

Yang F.,Northwest University, China | Yang F.,University of Nebraska - Lincoln | Hanna M.A.,University of Nebraska - Lincoln | Marx D.B.,University of Nebraska - Lincoln | Sun R.,Beijing Forestry University
International Journal of Energy Research | Year: 2013

Supercritical water gasification of crude glycerol for hydrogen (H2) production is one possible use of crude glycerol from biodiesel production. In this study, a series of central composite designed experiments were conducted to investigate the reforming of crude glycerol for producing a H2 rich gas. A mathematical model defining the effect of glycerol concentration, reaction temperature and KOH concentration was developed with response surface methodology and was used to improve the H2 yield. The study revealed that the optimum reaction conditions for producing H2 were 500°C, 7wt.% glycerol concentration and 2.39molL-1 KOH concentration. The corresponding pressure was 45MPa. Under these optimized reaction conditions, the H2 mole fraction yield in the gaseous product was 27.9±0.22mol%. The mole fraction yields of other gas products (CH4, CO and CO2) were small compared to that of H2. © 2012 John Wiley & Sons, Ltd.

Fang C.L.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Guan X.L.,National Academy for Mayors of China | Lu S.S.,Beijing Forestry University | Zhou M.,Peking University | Deng Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Urban Studies | Year: 2013

Urban agglomerations (UAs) in China play a vital role in the distribution of productive forces and constitute the most dynamic and potentially rich core areas for future economic development. However, the rapid economic growth and high-intensity interactions seen in relation to these areas, results of the high population densities and aggregation of industries in UAs, also pose significant ecological threats to the environment. This paper attempts to analyse changing trends in the input-output efficiency of UAs in China based on the data envelopment analysis (DEA) approach. The paper investigates the DEA efficiency of UAs with different population sizes and geographical locations, explores the relationship between the elements that make up a decomposed model of efficiency and compares the efficiency performance of China's UAs with that of 35 central cities. Moreover, the exogenous factors determining the input-output efficiency of UAs, the question of how to improve UAs' efficiency performance, as well as the focus of future research are also discussed. A number of valuable implications have been drawn from the study, which may be helpful to the task of understanding more deeply the high-density aggregation effects of UAs in China. © 2013 Urban Studies Journal Limited.

Chen L.,Northwest University, China | Cao S.,Northwest University, China | Cao S.,Beijing Forestry University
Ecological Engineering | Year: 2013

There are many factors have contributed to China's environmental crisis and are hindering environmental recovery campaigns. In particular, the implementation of government policy has played a strong role, both because of a government's natural slowness to change and because of structural impediments. Competition for a share of the huge investments that are being made to support environmental protection among various governmental departments and with local governments has also slowed progress. The conflicting socioeconomic policies that can result from this competition have undermined the large investments in environmental programs by failing to consider the environmental consequences of the conflicts, leading to inappropriate actions and compromising the ability to achieve environmental restoration goals. To improve governance and the ability to meet environmental goals, governments at all levels must understand the problem created by the competition that leads to weak coordination of efforts and must formulate revised policies that encourage sustainability by balancing economic growth with a careful consideration of the need for all groups, whether governmental or private sector, to benefit from these policies. © 2013 Elsevier B.V.

Xin Z.,Beijing Forestry University | Ran L.,National University of Singapore | Lu X.X.,National University of Singapore
International Journal of Water Resources Development | Year: 2012

The sediment load of the Loess Plateau has shown a sharp decreasing trend in the past decades. This paper gives a comprehensive review of the driving factors of the sediment decrease with respect to human activities, including soil and water conservation, dam construction, and vegetation restoration. Also presented is an overview of the main achievements of soil and water conservation and the main soil erosion control programmes implemented in the Loess Plateau. The paper concludes with suggestions for further policy modifications that could move management towards ecological sustainability and will be greatly beneficial to the regional water resources management and restoration of an eco-environmental system in the Loess Plateau. © 2012 Copyright Taylor and Francis Group, LLC.

Ma M.-G.,Beijing Forestry University
International Journal of Nanomedicine | Year: 2012

Hierarchically nanosized hydroxyapatite (HA) with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours. Objective: The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA) with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks. Methods: A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) assay. Results: HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did not decrease with the increasing concentration of hierarchically nanostructured HA added. Conclusion: A novel, simple and reliable hydrothermal route had been developed for the synthesis of hierarchically nanosized HA with flower-like structure assembled from nanosheets consisting of nanorod building blocks. The HA with the hierarchical nanostructure was formed via a soft-template assisted self-assembly mechanism. The hierarchically nanostructured HA has a good biocompatibility and essentially no in-vitro cytotoxicity. © 2012 Ma, publisher and licensee Dove Medical Press Ltd.

Zhong B.,Soil and Water Conservation Bureau of Changting County | Peng S.,Soil and Water Conservation Bureau of Changting County | Zhang Q.,Renmin University of China | Ma H.,Beijing Forestry University | Cao S.,Northwest University, China
Land Use Policy | Year: 2013

Land degradation and poverty are problems that must be tackled together for environmental conservation to succeed. However, it is rarely possible to move a population from degraded land to another area where the people can be more easily sustained. To find a new strategy that achieves both conservation and economic gains without the need to relocate a population, we examined/investigated a sustainable combination of ecological and economic development suitable for the restoration of areas of China with collapsing gullies, where the frequent steep slopes make restoration difficult. The results showed that the degraded land may contain significant benefits that were previously unappreciated, thereby transforming a problem into an opportunity. Our results suggest that the new approach can both improve the livelihoods of local citizens and promote environmental conservation, leading to successful ecological restoration. © 2012 Elsevier Ltd.

Polle A.,University of Gottingen | Chen S.,Beijing Forestry University
Plant, Cell and Environment | Year: 2015

Saline and sodic soils that cannot be used for agriculture occur worldwide. Cultivating stress-tolerant trees to obtain biomass from salinized areas has been suggested. Various tree species of economic importance for fruit, fibre and timber production exhibit high salinity tolerance. Little is known about the mechanisms enabling tree crops to cope with high salinity for extended periods. Here, the molecular, physiological and anatomical adjustments underlying salt tolerance in glycophytic and halophytic model tree species, such as Populus euphratica in terrestrial habitats, and mangrove species along coastlines are reviewed. Key mechanisms that have been identified as mediating salt tolerance are discussed at scales from the genetic to the morphological level, including leaf succulence and structural adjustments of wood anatomy. The genetic and transcriptomic bases for physiological salt acclimation are salt sensing and signalling networks that activate target genes; the target genes keep reactive oxygen species under control, maintain the ion balance and restore water status. Evolutionary adaptation includes gene duplication in these pathways. Strategies for and limitations to tree improvement, particularly transgenic approaches for increasing salt tolerance by transforming trees with single and multiple candidate genes, are discussed. © 2014 John Wiley & Sons Ltd.

Matin M.A.,University of New Brunswick | Bourque C.P.-A.,University of New Brunswick | Bourque C.P.-A.,Beijing Forestry University
Journal of Arid Environments | Year: 2015

The paper examines the role of mountain runoff in the seasonal growth of oasis vegetation in the hyper-arid region of northwest China. Central to this examination is the development of a simple hydrologic model that relates hydrologic inflows and outflows estimated from remote sensing data (e.g., evapotranspiration, precipitation, snow accumulation, and snowmelt) to the calculation of runoff over a ten-year period (2000-2009). Modeled runoff is shown to reproduce the seasonal trends in hydrometric data fairly well, yielding R2's of 0.75 and 0.66 for stations in the upper reaches of the Shiyang and Hei River systems. Greater than 90% of the runoff from the Qilian Mountains to the oases occurs during the May-September period. Considerable discrepancy between modeled and observed runoff exists in the lower reaches of the rivers, where significant amounts of river water (>45%) are routinely extracted for cropland irrigation. Along the river systems, where water extraction and inflow of glacial meltwater are minor, model calculations replicate observed water yields much more closely. Analysis of seasonal trends in the contribution of snowmelt and rainfall to the return flow, reveals snowmelt as having the greatest influence in initiating the oasis growing period during the March-to-May period of each year. © 2015 Elsevier Ltd.

Hsu B.B.,Massachusetts Institute of Technology | Ouyang J.,Beijing Forestry University | Wong S.Y.,Massachusetts Institute of Technology | Hammond P.T.,Massachusetts Institute of Technology | Klibanov A.M.,Massachusetts Institute of Technology
Biotechnology Letters | Year: 2011

Hydrophobic polycations previously developed by us efficiently kill E. coli and Staphylococcus aureus on contact. As visualized by electron microscopy herein, these pathogenic bacteria incur marked morphological damage from the exposure to these N-alkylated-polyethylenimine "paints" which results in the leakage of an appreciable fraction of the total cellular protein. The quantity and composition of that leaked protein is similar to that released upon traditional lysozyme/EDTA treatment, thus providing insights into the mechanism of action of our microbicidal coatings. © 2010 Springer Science+Business Media B.V.

Zhang C.,Taiyuan University of Technology | Chen L.,Beijing Forestry University | Jiang J.,Taiyuan University of Technology | Zhou S.,The MCC Group
Trees - Structure and Function | Year: 2012

Root tensile strength plays an important role in soil stabilization and fixation. Testing and separating the different factors that affect root tensile strength are important. In the present study, the effects of four factors, namely, gauge length, strain rate, species, and root diameter, on root tensile strength were studied. Uniaxial tensile tests were conducted to acquire the root tensile strength of five tree species commonly growing in the mountains of northern China, namely, Chinese pine (Pinus tabulaeformis Carr.), Larch (Larix principis-rupprechtii Mayr.), White birch (Betula platyphylla Suk.), Mongolian oak (Quercus mongolicus Fisch.), and Elm (Ulmus pumila L.). Based on the results, Elm and White birch roots were the most resistant to tension, followed by Mongolian oak and Chinese pine roots. Larch roots were found to be the least resistant to tension. A power relationship was established between root diameter and root tensile strength. Based on linear regression analysis, gauge length was negatively correlated with root tensile strength. Tensile strength decreased with increasing gauge length. In addition, an unexpected variation of tensile strength was observed between two strain rates (10 and 400 mm min -1). The present study can serve as a basis for further studies on mechanical properties of root system and root reinforcement under different test circumstances, although this should be done with caution. © 2012 Springer-Verlag.

Tang Z.,University of Nebraska - Lincoln | Wang Z.,Beijing Forestry University | Koperski T.,University of Nebraska - Lincoln
International Journal of Climate Change Strategies and Management | Year: 2011

Purpose: The purpose of this study is to measure local climate change response capacity and identify the existing gaps between local climate change action plans and land use plans. Design/methodology/approach: This study uses content analysis method to statistically analyze 40 pioneering local jurisdictions' climate change action plans and land use plans. Findings: The results show significant gaps in the two types of plans. Local climate change action plans have a higher quality of plan components including factual basis, targets, coordination, and communication than local land use plans. However, local land use plans have an even higher quality of policy plan components than action plans. Originality/value: This study has extended established climate change concepts and practices by incorporating climate change considerations into the existing framework of local decision making. © Emerald Group Publishing Limited.

Zheng Y.,Beijing Forestry University
Applied Mechanics and Materials | Year: 2011

In this paper, a novel mobile robot is introduced. The mechanical structure, control system and the simplified dynamic model of the robot are given particularly. Moreover, the pose and velocity control strategies of the robot is presented respectively. Finally, the mechanical structure and control strategies are validated through a series of experiments. © (2011) Trans Tech Publications, Switzerland.

Zhou Q.,Renmin University of China | Zhang P.,Beijing Forestry University | Zhang G.,Renmin University of China
Bioresource Technology | Year: 2014

The present study is aimed at enhanced cell production in together with pollution removal in photosynthetic bacteria wastewater treatment through low-strength ultrasound stimulation. The ultrasound strength was 0.3W/cm2 with 40kHz frequency. Results showed 1-10min sonication significantly improved the cell production. The optimal sonication time was 2min. When the irradiation period was over 10min, a strong mechanical damage occurred. These phenomena could be explained by the changes of PSB dehydrogenase activity. Sonication stimulated the initial dehydrogenase activity; moderate sonication increased the cell activity while too-long sonication led to quick enzyme activity decrease. The optimal sonication strategy was 1min at the 0th hour and 1min at the 27th hour. The corresponding cell production and cell yield increased by 110% and 93% respectively, and the COD removal reached 98%. The cost of low-strength ultrasound was only 1% of the incremental sales value of cells. © 2014 Elsevier Ltd.

Fang N.,Utah State University | Zhao X.,Beijing Forestry University
Proceedings - Frontiers in Education Conference, FIE | Year: 2013

This paper presents the results of a comparative study of learning style preferences between American and Chinese undergraduate engineering students. A total of 132 sophomore engineering students from two American and Chinese universities responded to an Index of Learning Styles (ILS) survey. The survey is a 44-item, self-scoring questionnaire that assesses learning style preferences on four pairs of dimensions of the Felder-Silverman model: active/reflective, sensing/intuitive, visual/verbal, and sequential/global. Descriptive statistics and independent sample t-tests are performed to analyze students' responses to the survey. The results show that statistically significant differences exist in four dimensions (reflective, sensing, visual, and verbal) between American and Chinese students. Overall, American students show higher preferences in all four of these dimensions than do Chinese students. © 2013 IEEE.

He Q.,Nanjing Forestry University | Berg A.,Pennsylvania State University | Li Y.,West Virginia University | Vallejos C.E.,University of Florida | And 3 more authors.
Trends in Genetics | Year: 2010

One of the fundamental tasks in biology is the identification of genes that control the structure and developmental pattern of complex traits and their responses to the environment during trait development. Functional mapping provides a statistical means for detecting quantitative trait loci (QTLs) that underlie developmental traits, such as growth trajectories, and for testing the interplay between gene action and development. Here we describe how functional mapping and studies of plant ontology can be integrated so as to elucidate the expression mechanisms of QTLs that control plant growth, morphology, development, and adaptation to changing environments. This approach can also be used to construct an evo-devo framework for inferring the evolution of developmental traits. © 2009 Elsevier Ltd. All rights reserved.

Zhang A.,South China University of Technology | Lu F.,University of Wisconsin - Madison | Sun R.-C.,South China University of Technology | Sun R.-C.,Beijing Forestry University | Ralph J.,University of Wisconsin - Madison
Journal of Agricultural and Food Chemistry | Year: 2010

Attempts were made to enhance polysaccharide digestibility by crude cellulases in the isolation of cellulolytic enzyme lignin (CEL) by dissolution of ball-milled wood in a dimethyl sulfoxide (DMSO)/Nmethylimidazole solvent system as a pretreatment step. Wood regenerated from the DMSO/Nmethylimidazole solution was hydrolyzed with crude cellulases for 48 h, removing 73.7 and 66.9% of the original carbohydrate for basswood and loblolly pine, respectively; only 61.7 and 49.2% were hydrolyzed by the crude cellulases without pretreatment. The yields of CEL isolated from regenerated ball-milled wood samples were therefore higher than those directly from ball-milled wood material, presumably via decreasing crystallinity of cellulose. For basswood, the yields of lignin were 45.8 and 36.5% (based on Klason lignin); for loblolly pine, the yields were 35.3 and 30.5%. The isolated lignins were structurally examined using two-dimensional heteronuclear single-quantum coherence (1H- 13C HSQC) NMR methods, which showed that the main structural characteristics of the lignin fractions obtained using these two methods are similar except for slightly higher amounts of carbohydrates in the solvent dissolution product. ©2010 American Chemical Society.

Liu B.,South China University of Technology | Li X.,South China University of Technology | Zheng C.,South China University of Technology | Wang X.,South China University of Technology | And 2 more authors.
Nanotechnology | Year: 2013

A facile and green method to synthesize stable Ag nanoparticles (Ag NPs) with a narrow size distribution in water is reported. Water-soluble quaternized carboxymethyl chitosan (QCMC) with a surfactant-like structure was used as both a reducing and stabilizing agent under microwave irradiation via the modified Tollens reaction. In order to study the preparation mechanism, carboxymethyl chitosan (CMC) and quaternized chitosan (QCS) were compared as both reducing and stabilizing agents. Full characterization was performed using UV-vis, XRD, TEM, AAS, FT-IR, NMR and TGA. The results revealed that the prepared Ag NPs were mostly spherical with a small proportion being cylinders or cuboids; they were stable due to the package of the macromolecules; the diameters were 10.24 ± 3.13 nm. The Tollens reaction followed first order kinetics, and the Ea was 102.4 kJ mol-1 for QCMC/Ag NP composite. During the growth of the Ag NPs, some quaternary ammonium groups and carboxymethyl groups were respectively oxidized to -CH2COCH3 and -CH 3 groups, and the quaternary ammonium groups were more helpful for the growth of Ag NPs than the carboxymethyl groups. In addition, QCMC/Ag NP composite had much higher thermal stability than QCMC. © 2013 IOP Publishing Ltd.

Cao S.,Beijing Forestry University | Wang X.,China Agricultural University | Song Y.,China Agricultural University | Chen L.,CAS Institute of Soil and Water Conservation | Feng Q.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute
Ecological Economics | Year: 2010

Conservation of the ecological environment presents scientists with a challenging dilemma because the strategy often leads to negative impacts on impoverished people in the area affected by the project. To consider this problem, we investigated the implications of China's national and regional policies related to the Natural Forest Conservation Program (NFCP) for poverty in the dryland regions of northern Shaanxi Province. We found that 34.9, 47.0, and 59.8% of farmers, livestock grazers, and forest workers respectively, felt that their livelihoods had been adversely affected by the NFCP due to the ban on logging and grazing imposed by this program, and they perceived additional economic losses because they were not adequately compensated for their economic losses under the program. These perceptions are supported by economic data. In addition, our results showed that the poorer the survey respondent, the greater the likelihood they believed that they had suffered from the implementation of the NFCP. Although Chinese citizens have become more favorable towards environmental conservation efforts, the poorest citizens still need considerable help to make it possible for them to participate in both economic development and environmental restoration. © 2009 Elsevier B.V. All rights reserved.

Luo Z.,CSIRO | Wang E.,CSIRO | Sun O.J.,Beijing Forestry University
Soil Biology and Biochemistry | Year: 2016

Priming of soil organic matter decomposition by fresh carbon inputs is a key ecological process determining soil carbon (C) and nutrient cycling in terrestrial ecosystems. Although this priming effect (PE) has been studied under various environmental conditions, the conclusions are inconsistent across space and time and the underlying mechanisms unclear. We used a meta-analysis with extensive datasets of CO2 effluxes from soils with 13C or 14C labelled fresh C inputs and without fresh C inputs under various soil conditions to synthesize and assess the temporal dynamics of the PE. The results indicated that the PE declined in 20 days on average from 67−21 +26% (95% confidence interval) immediately following the fresh C inputs to less than 7.6−1.8 +2.0% and remained relatively stable thereafter. We also assessed the variability of the temporal dynamics of the PE in the collected datasets and the underlying drivers. The results showed that the magnitude of PE at a specific time (i.e., the instantaneous PE after the fresh C inputs) was significantly and positively correlated with the instantaneous quantity of remaining fresh C. Under the same quantity of remaining fresh C, the PE varied significantly across ecosystems (in the order of grasslands < farmlands < forests < other ecosystems such as lake beds and volcanic soils), but, contrary to our expectation, the PE was independent of the quality of the added fresh C. We found that the PE experienced a faster decrease in soils with higher clay and moisture contents. These results describe the temporal dynamics of PE and the underlying drivers, underpinning the robust predictions of PE dynamics and their impact on soil C and nutrient balances. © 2016 Elsevier Ltd

Zhou J.,Beijing Forestry University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

In order to reduce wind-induced vibration damage of forest, four spring dampers in casing pipe were developed based on vibration reduction theory in this article, and wind-induced vibration reduction of four Populus alba var. pyramidalis specimens were carried out separately by them. In a self-made simple wind tunnel, contrast tests of vibration reduction with/without the action of damper were carried out by simulating natural wind environment; comparative characteristics curves of wind-induced dynamic strain, wind-induced dynamic displacement, wind-induced dynamic speed and wind-induced dynamic acceleration response were obtained. Results showed that wind-induced dynamic response of forest could be measured by strain gages pasting on forest and charge accelerometer installed on forest, and wind-induced dynamic peak response, such as strain, displacement, velocity and acceleration, could be reduced effectively by spring damper in casing pipe fixed on forest, and the effect of vibration reduction of forest equipped with spring damper in casing pipe was very good. Spring damper in casing pipe developed in this paper has features such as relative simple structure, low cost, and good weather resistance, and therefore it is suitable for popularization over large areas, especially suitable for wind disaster protection of forest in difficult stand conditions. Wind disaster protection of forest are carried out through the use of spring damper in casing pipe developed in this paper, and the methods in this paper give a new approach to wind disaster protection of forest.

Ma X.,Tianjin University of Science and Technology | Zhao G.,Beijing Forestry University
Journal of Applied Polymer Science | Year: 2011

After spinning by adding hexamethylenetetramine and the curing treatment, carbon fibers from liquefied wood (LWCFs) were prepared by direct carbonization. Microstructure change of LWCFs during carbonization is studied by X-ray, Raman spectroscopy, and FTIR. Raman spectroscopy shows both the D peak at 1360 cm -1 and the G peak at 1595 cm-1 exist after 600°C, and a significant decrease is found in ID/IG during carbonization. X-ray diffraction shows the crystallite size (Lc (002) and La(100)) of LWCFs firstly decreases before 800°C and then increases with heat treatment temperature (HTT) increasing, whereas the interlayer spacing (d002) gradually decreases during carbonization. It is also found that the crystallite shape (L a/Lc) and the degree of graphitization (G) all increase with increasing HTT. It is also found that structure of the precursor fibers from liquefied wood has been completely changed after carbonization. © 2011 Wiley Periodicals, Inc.

Chen M.,South China University of Technology | Zhang X.,South China University of Technology | Liu C.,South China University of Technology | Sun R.,South China University of Technology | And 2 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2014

Lignocellulosic biomass in the form of plant materials offers the most abundant renewable resource in replacing traditional fossil resources. In the present study, lignocellulosic biomass films were prepared directly from bagasse solutions in DMSO/LiCl without additional film-forming additives by coagulation either in an acetone/water (9/1, v/v) mixture or in water following a freezing treatment. The physicochemical properties of bagasse films were studied by FT-IR, UV/vis, SEM, XRD, and tensile testing. The films were semi-transparent with a yellow color and showed strong abilities in UV light blocking due to the presence of lignin. Relatively high mechanical strength comparable to cellulose-starch-lignin composite films was observed. The physical cross-link and the stress buffer of micropores formed in the freezing treatment resulted in enhanced mechanical strength of the film. The facile and environmentally friendly process creates a new strategy for converting abundant lignocellulosic materials to novel value-added bioproducts. © 2014 American Chemical Society.

Yu Y.,Beijing Institute of Technology | Wang X.,Beijing Institute of Technology | Wang D.,Beijing Institute of Technology | Huang K.,Beijing Forestry University | And 3 more authors.
Journal of Hazardous Materials | Year: 2012

An environmental impact assessment model for secondary batteries under uncertainty is proposed, which is a combination of the life cycle assessment (LCA), Eco-indicator 99 system and Monte Carlo simulation (MCS). The LCA can describe the environmental impact mechanism of secondary batteries, whereas the cycle performance was simulated through MCS. The composite LCA-MCS model was then carried out to estimate the environmental impact of two kinds of experimental batteries. Under this kind of standard assessment system, a comparison between different batteries could be accomplished. The following results were found: (1) among the two selected batteries, the environmental impact of the Li-ion battery is lower than the nickel-metal hydride (Ni-MH) battery, especially with regards to resource consumption and (2) the lithium ion (Li-ion) battery is less sensitive to cycle uncertainty, its environmental impact fluctuations are small when compared with the selected Ni-MH battery and it is more environmentally friendly. The assessment methodology and model proposed in this paper can also be used for any other secondary batteries and they can be helpful in the development of environmentally friendly secondary batteries. © 2012.

Zeng Y.,Zhejiang Agriculture And forestry University | Hou W.,University of Florida | Song S.,Zhejiang Agriculture And forestry University | Feng S.,Beijing Forestry University | And 3 more authors.
Briefings in Bioinformatics | Year: 2014

The capacity of apomixis to generate maternal clones through seed reproduction has made it a useful characteristic for the fixation of heterosis in plant breeding. It has been observed that apomixis displays pronounced intra- and interspecific diversification, but the genetic mechanisms underlying this diversification remains elusive, obstructing the exploitation of this phenomenon in practical breeding programs. By capitalizing on molecular information in mapping populations, we describe and assess a statistical design that deploys linkage analysis to estimate and test the pattern and extent of apomictic differences at various levels from genotypes to species. The design is based on two reciprocal crosses between two individuals each chosen from a hermaphrodite or monoecious species. A multinomial distribution likelihood is constructed by combining marker information from two crosses. The EM algorithm is implemented to estimate the rate of apomixis and test its difference between two plant populations or species as the parents. The design is validated by computer simulation. A real data analysis of two reciprocal crosses between hickory (Carya cathayensis) and pecan (C. illinoensis) demonstrates the utilization and usefulness of the design in practice. The design provides a tool to address fundamental and applied questions related to the evolution and breeding of apomixis. © The Author 2012. Published by Oxford University Press.

Ahmad M.,Kangwon National University | Lee S.S.,Kangwon National University | Dou X.,Beijing Forestry University | Mohan D.,Jawaharlal Nehru University | And 3 more authors.
Bioresource Technology | Year: 2012

Conversion of crop residues into biochars (BCs) via pyrolysis is beneficial to environment compared to their direct combustion in agricultural field. Biochars developed from soybean stover at 300 and 700. °C (S-BC300 and S-BC700, respectively) and peanut shells at 300 and 700. °C (P-BC300 and P-BC700, respectively) were used for the removal of trichloroethylene (TCE) from water. Batch adsorption experiments showed that the TCE adsorption was strongly dependent on the BCs properties. Linear relationships were obtained between sorption parameters (K M and S M) and molar elemental ratios as well as surface area of the BCs. The high adsorption capacity of BCs produced at 700. °C was attributed to their high aromaticity and low polarity. The efficacy of S-BC700 and P-BC700 for removing TCE from water was comparable to that of activated carbon (AC). Pyrolysis temperature influencing the BC properties was a critical factor to assess the removal efficiency of TCE from water. © 2012 Elsevier Ltd.

Huitao S.,East China Normal University | Xiaoxue W.,Beijing Forestry University | Xiaoxue W.,CAS Research Center for Eco Environmental Sciences | Yue J.,East China Normal University | Wenhui Y.,East China Normal University
Hydrological Processes | Year: 2012

Linking spatial variations of throughfall with shifting patterns during forest succession is important for understanding developmental patterns of ecosystem function. However, no such approach has been previously used for the chronosequence of evergreen broad-leaved forests in subtropical regions. This study was conducted in a chronosequence of secondary forest succession in Tiantong National Forest Park, to determine the optimum number of collectors within certain limits of error. Throughfall was 66, 55 and 77% of gross precipitation in an early-succession (SS), sub-climax (SE) and climax (CE) forest, respectively. The coefficient of variations (CV) of throughfall reduced with increasing rainfall amounts. Monte Carlo resampling approach was used to find mean values and 90 and 95% confidence intervals of a variable number of collectors (n) ranging from 2 to 24. During the study period, with nine collectors at SS, five at SE and five at CE, the error in the mean individual throughfall did not exceed 10%, respectively. This error was reduced to 5% when using 16, 10 and 10 collectors at SS, SE and CE, respectively. The CVs decreased greatly with increasing sample size when the sample size was less than 16 for the three successional stages, regardless of rainfall amounts. Based on the Student'st-value analysis of the mean individual throughfall volumes, a sample size of 16 at SS, five at SE and four at CE would be enough for throughfall estimates at an accepted error of 10% of 95% confidence level, respectively. Therefore, we concluded that the 25 of collectors used in the present study were sufficient to estimate the throughfall value at an accepted error of 10% at 90 and 95% confidence levels, even for those small rainfalls in eastern China. © 2011 John Wiley & Sons, Ltd.

Hu D.,CAS Research Center for Eco Environmental Sciences | Guo Z.,CAS Research Center for Eco Environmental Sciences | Wang Z.,Beijing Forestry University | Xiao Q.,CAS Research Center for Eco Environmental Sciences
Ecological Informatics | Year: 2015

As one of the primary raw materials in the construction industry, cement production consumes a great deal of resources and has various environmental effects. During the production phase in particular, different procedures play a decisive role in determining the input and output. China has become both the largest producer and the largest consumer of cement worldwide. Together, the two most common production processes in China, the shaft kiln and the NSP (New Suspension Preheater) kiln, account for more than 95% of total production capacity. Although the proportion of NSP kilns continues to increase each year, shaft kilns are still adopted in numerous small and medium-sized enterprises due to their lower costs and quick yields. During the period of technical transformation and the emergence of continuous environmental issues, it is of great importance to quantify the metabolic processes of typical construction materials, particularly in order to conduct a comparative analysis with different production techniques. However, due to the limited availability of data, relevant studies are rare. In this paper, two typical cement enterprises with different production processes were selected in order to investigate material and energy use as well as pollutant emissions. Metabolic processes were then compared and a use efficiency analysis for different procedural phases was conducted using material flow analysis (MFA). The results are as follows: the shaft kiln requires more raw materials, such as limestone, clay, and coal, per unit product. The efficiency of energy consumption (including electric power consumption and overall energy consumption) is also lower for the shaft kiln than for the NSP kiln. As for environmental emissions, the shaft kiln emits more SO2, CO2, NOX, and dust per unit product than the NSP kiln and has higher eco-environmental impacts. © 2014 Elsevier B.V.

Liu B.,South China University of Technology | Shen S.,South China University of Technology | Luo J.,South China Normal University | Wang X.,South China University of Technology | And 2 more authors.
RSC Advances | Year: 2013

A rapid and green method is reported to synthesize silver nanoparticles (Ag NPs) and simultaneously achieve exfoliated chitosan/clay nanocomposite under microwave irradiation, in which quaternized chitosan (QCS), montmorillonite (MMT) and Gemini surfactant were used as reducing and stabilizing agents, other chemical reductants were not involved. XRD, FT-IR, NMR, TEM and AAS were performed to characterize Ag NP-loaded QCS/clay nanocomposites. The results indicated that the formation of spherical Ag NPs (about 26 nm) were mainly associated with reduction effect of QCS, surfactant and clay hardly participate in the synthesis of Ag NP, but benefited its formation. During the formation of Ag NPs, the layers of clay were peeled, the exfoliated Ag NP-loaded QCS/clay nanocomposites were obtained. Moreover, Ag NP-loaded QCS/clay nanocomposites showed excellent antimicrobial activity. The lowest minimum inhibition concentration against microorganisms was 0.00001 wt%. At last, the antimicrobial mechanism was evaluated by TEM and SEM micrographs. © 2013 The Royal Society of Chemistry.

Chuanhe H.,Beijing Forestry University
51st World Congress of the International Federation of Landscape Architects, IFLA 2014 | Year: 2014

Duolun located in the north of Beijing,China where is the source of the Luan River also in the southern end of Hunshandake desert where is the starting point of the sandstorm moving path from inner Mongolia to Beijing. In order to nurture the ecological environmental consciousness of the youth we plan to construct an outdoor educational practice site here. This essay takes the planning of Ecological practice site for the youth as an example to discuss how to demonstrate the transformation of desertification mountain in order to reveal the mystery of soil and water conservation technology, plant landscape diversity, energy saving and low carbon technology in the limited areas of 180-ha. And how to create an ecological practice site that combines ecological exemplary education and participatory education. Study will become an entertainment when teenagers were involved in popular science, natural experience and cultural awareness of activities in each seasons also can promote ecological civilization concept, strengthening the consciousness of ecological safety and realize the goal of ecological construction.

Peng W.,Beijing Forestry University
51st World Congress of the International Federation of Landscape Architects, IFLA 2014 | Year: 2014

Northwest suburb to Beijing has superior natural environment surrounded by mountains. Researches have shown abundant groundwater in the history and springs gush all year round. The natural environment used to attract emperors to live and work here which formed a large area of the imperial gardens, including the Fragrant Hill Park, Yuquan Hill Jing Ming Yuan, Qing Yi Park Wanshou Hill, Summer Palace, and Chang Chun, historically known as the " three hills and five gardens." Meanwhile, it also attracts a lot of celebrities, officials and common people to visit and settle here leaving a number of noble gardens, private residence gardens, temple, celebrities residences, etc,thus it become the second political center besides the Forbidden City. For 800 years, three hills and five gardens have witnessed Beijing's development from establishing Beijing as capital, through Yuan and Ming dynasty till now it has formed a multicultural area based on gardens, celebrities residences, temples, tombs, homes of eight banners, and farmlands. However, with rapid urbanization in Beijing, "three hills and five gardens " has been threatened by urban construction and tourism development.

Schonherr C.,Umea University | Yang H.-L.,Beijing Forestry University | Vigny M.,French Institute of Health and Medical Research | Palmer R.H.,Umea University | Hallberg B.,Umea University
Oncogene | Year: 2010

Many different types of cancer originate from aberrant signaling from the anaplastic lymphoma kinase (ALK) receptor tyrosine kinase (RTK), arising through different translocation events and overexpression. Further, activating point mutations in the ALK domain have been recently reported in neuroblastoma. To characterize signaling in the context of the full-length receptor, we have examined whether ALK is able to activate Rap1 and contribute to differentiation/proliferation processes. We show that ALK activates Rap1 via the Rap1-specific guanine-nucleotide exchange factor C3G, which binds in a constitutive complex with CrkL to activated ALK. The activation of the C3G/Rap1 pathway results in neurite outgrowth of PC12 cells, which is inhibited by either overexpression of Rap1GAP or siRNA-mediated knockdown of Rap1 itself or the guanine nucleotide exchange factor C3G. Significantly, this pathway also appears to function in the regulation of proliferation of neuroblastoma cells such as SK-N-SH and SH-SY5Y, because abrogation of Rap1 activity by Rap1-specific siRNA or overexpression of Rap1GAP reduces cellular growth. These results suggest that ALK activation of Rap1 may contribute to cell proliferation and oncogenesis of neuroblastoma driven by gain-of-function mutant ALK receptors. © 2010 Macmillan Publishers Limited All rights reserved.

Zhang W.-P.,Zhejiang University | Jia X.,Beijing Forestry University | Morris E.C.,University of Western Sydney | Bai Y.-Y.,Guangxi Traditional Chinese Medical University | Wang G.-X.,Zhejiang University
Ecological Research | Year: 2012

Defining and quantifying biomass-density relationships in dense plant stands has been a long-standing issue in both theoretical and empirical studies. Most existing/traditional studies focus on whole plant individuals, without considering different plant components (e. g., stem, branch and leaf). However, the analysis of biomass-density relationships for different plant parts is linked to those for whole plants, and thus important for understanding plant strategies for utilizing resources and community dynamics. In our study, we investigated standing stem (M S), branch (M B) and leaf (M L) biomass-density relationships, across a range of forest communities in China. The results showed that there was no constant predicted value (e.g., -1/2 or -1/3 for M S; -1/2, -1/3 or 0 for M B and M L) that can describe all the relationships, and that the scaling exponents for stem, branch and leaf biomass varied across different forest types. In particular, standing leaf biomass (leaf biomass per unit area) was not constant in these forest communities. Furthermore, stem biomass-density lines were steeper than corresponding branch and leaf lines across most of these forest communities. © 2012 The Ecological Society of Japan.

Wang S.,South China University of Technology | Ren J.,South China University of Technology | Li W.,South China University of Technology | Sun R.,South China University of Technology | And 3 more authors.
Carbohydrate Polymers | Year: 2014

Composite films of xylan and polyvinyl alcohol were produced with citric acid as a new plasticizer or a cross-linking agent. The effects of citric acid content and polyvinyl alcohol/xylan weight ratio on the mechanical properties, thermal stability, solubility, degree of swelling and water vapor permeability of the composite films were investigated. The intermolecular interactions and morphology of composite films were characterized by FTIR spectroscopy and SEM. The results indicated that polyvinyl alcohol/xylan composite films had good compatibility. With an increase in citric acid content from 10% to 50%, the tensile strength reduced from 35.1 to 11.6 MPa. However, the elongation at break increased sharply from 15.1% to 249.5%. The values of water vapor permeability ranged from 2.35 to 2.95 × 10-7 g/(mm2 h). Interactions between xylan and polyvinyl alcohol in the presence of citric acid become stronger, which were caused by hydrogen bond and ester bond formation among the components during film forming. © 2013 Published by Elsevier Ltd.

Xu B.,Northwestern Polytechnical University | Wang S.,Yantai Naval Aeronautical and Astronautical University | Wang S.,Tsinghua University | Gao D.,Beijing Forestry University | And 2 more authors.
Journal of Intelligent and Robotic Systems: Theory and Applications | Year: 2014

The command filter based robust nonlinear controller is designed for the longitudinal dynamics of a generic hypersonic aircraft in presence of parametric model uncertainty and magnitude constraints on the states and actuators. The functional subsystems are transformed into the linearly parameterized form and the controller is proposed based on dynamic inversion and adaptive gain. Since the dynamics are with cascade structure, the states are considered as virtual control and the signal is filtered to produce the limited command signal and its derivative. To eliminate the effect of the constraint, the auxiliary error compensation design is employed and the parameter projection estimation is proposed based on the compensated tracking error. The uniformly ultimately boundedness is guaranteed for the closedloop control system. Simulation results show that the proposed approach achieves good tracking performance. © Springer Science+Business Media Dordrecht 2013.

Zhou Y.,Beijing Forestry University
Engineering Technology, Engineering Education and Engineering Management - International Conference on Engineering Technology, Engineering Education and Engineering Management, ETEEEM 2014 | Year: 2015

Along with the development of economic globalization, the influence of the world financial crisis has permeated into everybody’s life. To help people have a better understanding of the pattern of the crisis, the chief aim of this article is to rank the impact of the world financial crisis on China during the previous 45 years. We initially use Literature Method and Expert Interviews Method to determine the indicator of our evaluate system, as the indicators are largely influenced by the erosion of the value of the currency. We introduce Loss Degree, which is the ratio of the indicator, and Gross National Income to eliminate this impact. After processing these data, the weight of each indicator can be calculated by using Analytic Hierarchy Process and we can get our ranking through substituting the crisis data into our evaluate system. The result we obtained proved that the impact of the world financial crisis on China increases along with the development of an era. © 2015 Taylor & Francis Group, London.

Hou F.M.,Beijing Forestry University
Advanced Materials Research | Year: 2013

The supply of environment-friendly products is an integral part of the green supply chain. Due to such reasons as lack of high-tech and lack of price competitiveness in contrast to traditional products, the manufacturers will not have incentive to produce and supply green products, so the Government should grant financial subsidies to producers which will compensate the profits entitled to them. Through the analysis based on game theory, the article concludes that there is disadvantage in constant subsidy and the variable subsidies will have more positive effects on the supply of environment-friendly products since the subsidy amount varies with the production scale. © (2013) Trans Tech Publications, Switzerland.

Fan J.,Beijing Forestry University | Johnson M.H.,University of Illinois at Urbana - Champaign | Lila M.A.,North Carolina State University | Yousef G.,North Carolina State University | De Mejia E.G.,University of Illinois at Urbana - Champaign
Evidence-based Complementary and Alternative Medicine | Year: 2013

Beneficial health effects of fruits and vegetables in the diet have been attributed to their high flavonoid content. Dipeptidyl peptidase IV (DPP-IV) is a serine aminopeptidase that is a novel target for type 2 diabetes therapy due to its incretin hormone regulatory effects. In this study, well-characterized anthocyanins (ANC) isolated from berry wine blends and twenty-seven other phenolic compounds commonly present in citrus, berry, grape, and soybean, were individually investigated for their inhibitory effects on DPP-IV by using a luminescence assay and computational modeling. ANC from blueberry-blackberry wine blends strongly inhibited DPP-IV activity (IC50, 0.07 ± 0.02 to >300 M). Of the twenty-seven phenolics tested, the most potent DPP-IV inhibitors were resveratrol (IC50, 0.6 ± 0.4 nM), luteolin (0.12 ± 0.01 M), apigenin (0.14 ± 0.02 M), and flavone (0.17 ± 0.01 M), with IC50 values lower than diprotin A (4.21 ± 2.01 M), a reference standard inhibitory compound. Analyses of computational modeling showed that resveratrol and flavone were competitive inhibitors which could dock directly into all three active sites of DPP-IV, while luteolin and apigenin docked in a noncompetitive manner. Hydrogen bonding was the main binding mode of all tested phenolic compounds with DPP-IV. These results indicate that flavonoids, particularly luteolin, apigenin, and flavone, and the stilbenoid resveratrol can act as naturally occurring DPP-IV inhibitors. © 2013 Junfeng Fan et al.

Si L.,Beijing Forestry University
Scientific World Journal | Year: 2015

In the Euclidean space R3, denote the set of all points with integer coordinate by Z3. For any two-dimensional simple lattice polygon P, we establish the following analogy version of Pick's Theorem, kIP+1/2BP-1, where BP is the number of lattice points on the boundary of P in Z3, IP is the number of lattice points in the interior of P in Z3, and k is a constant only related to the two-dimensional subspace including P. © 2015 Lin Si.

Liu J.,Beijing Forestry University | Lundqvist J.,Stockholm International Water Institute | Weinberg J.,Stockholm International Water Institute | Gustafsson J.,Stockholm International Water Institute
Environmental Science and Technology | Year: 2013

Conventional approaches to food security are questionable due to their emphasis on food production and corresponding neglect of the huge amount of food losses and waste. We provide a comprehensive review on available information concerning China's food losses and waste. The results show that the food loss rate (FLR) of grains in the entire supply chain is 19.0% ± 5.8% in China, with the consumer segment having the single largest portion of food waste of 7.3% ± 4.8%. The total water footprint (WF) related to food losses and waste in China in 2010 was estimated to be 135 ± 60 billion m 3, equivalent to the WF of Canada. Such losses also imply that 26 ± 11 million hectares of land were used in vain, equivalent to the total arable land of Mexico. There is an urgent need for dialogue between actors in the supply chain, from farmer to the consumer, on strategies to reduce the high rates of food losses and waste and thereby make a more worthwhile use of scarce natural resources. © 2013 American Chemical Society.

In this paper, we propose the Hamming distance, Euclidean distance, Hausdorff distance and generalized distance between interval-valued hesitant fuzzy sets (IVHFSs). Then, we propose the generalized normalized distance similarity measure for IVHFSs and the generalized Hausdorff normalized distance similarity measure for IVHFSs, and apply them to multicriteria decision-making. Through distance similarity measures between the ideal alternative and each alternative, we can rank all the alternatives. Finally, we give two illustrative examples to demonstrate the application of distance similarity measures for IVHFSs to multicriteria decision-making. © 2013 Taylor & Francis.

Xu B.,Tsinghua University | Sun G.,Beijing Forestry University | Yu R.,Tsinghua University | Yang Z.,Tsinghua University
IEEE Transactions on Parallel and Distributed Systems | Year: 2013

Localization is of great importance in mobile and wireless network applications. Time Difference of Arrival (TDOA) is one of the widely used localization schemes, in which the target (source) emits a signal and a number of anchors (receivers) record the arriving time of the source signal. By calculating the time difference of different receivers, the location of the target is estimated. In such a scheme, receivers must be precisely time synchronized. But time synchronization adds computational cost, and brings errors which may lower localization accuracy. Previous studies have shown that existing time synchronization approaches using low-cost devices are insufficiently accurate, or even infeasible under high requirement for accuracy. In our scheme (called Whistle), several asynchronous receivers record a target signal and a successive signal that is generated artificially. By two-signal sensing and sample counting techniques, time synchronization requirement can be removed, while high time resolution can be achieved. This design fundamentally changes TDOA in the sense of releasing the synchronization requirement and avoiding many sources of errors caused by time synchronization. We implement Whistle on commercial off-the-shelf (COTS) cell phones with acoustic signal and perform simulations with UWB signal. Especially we use Whistle to localize nodes of large-scale wireless networks, and also achieve desirable results. The extensive real-world experiments and simulations show that Whistle can be widely used with good accuracy. © 1990-2012 IEEE.

Huang H.,Beijing Forestry University
Gaojishu Tongxin/Chinese High Technology Letters | Year: 2014

To investigate the FOV (field of view) effect in field multi-angular remote sensing, a realistic structural computation model was extended to simulate the process of field measurements on maize and wheat canopies and assess FOV-induced measurement errors. The extended module was compared with the POV-Ray (persistence of vision raytracer) model, and the same simulation results were obtained. The results showed that the FOV effect resulted in a large BRF (bidirectional reflectance factor) error of 0.1 in near infrared regions. Maize canopies had a more significant FOV effect than wheat canopies. At a large FOV, the hotspot position, size and width could not be precisely captured. The extension improved simulation capabilities under large FOV conditions for realistic structural models. The simulation results confirmed the consistence between the "fix-area" method and the "fix-pixel" method, as well as the feasibility of using large FOV on wheat canopies. The conclusions will help field experiments and theoretical modeling of crop canopies, and provide support for multi-angular remote sensing research.

Liu H.,Henan University of Technology | Ma M.,Beijing Forestry University | Liu Y.,Henan University of Technology
Progress in Chemistry | Year: 2014

With the increasing consumption of fossil fuels and the growing concerns about climate change, biomass is drawing increasing attention as a renewable energy source due to its advantages of renewal and abundance. Biomass can be converted into energy using bio-chemical and thermo-chemical processes, but the thermo-chemical conversion technology finds its dominance because of high efficient conversion to gas, liquid and solid products under thermal conditions. Biomass pretreatment can alter the physical features and chemical composition/structure of lignocellulosic materials. The pretreatment step has a significant influence on the quality and yield of products obtained from thermo-chemical conversion biomass. In this review, we discuss the applications of various pretreatment methods in the biomass thermo-chemical conversion, including torrefaction and gasification, pretreatment and biomass pyrolysis, pretreatment and biomass liquefaction. Torrefaction improves the hydrophobicity and grindability characteristics of biomass materials. Water or acid washing pretreatment can remove metal ions from biomass and the change in products distribution during the biomass pyrolysis is more obvious. Biomass pretreatment and liquefaction can increase the bio-oil yield and decrease the optimum reaction temperature compared to the untreated biomass liquefaction experiments.

Wang Y.L.,Beijing Forestry University | Dentel S.K.,University of Delaware
Water Research | Year: 2010

Wastewater sludges are non-Newtonian fluids because their shear rates change with shear stress and no linear relationship is observed between their shear stress and shear rate. Therefore, it is necessary to condition sludges with polyelectrolytes prior to dewatering to increase in the dewaterability. Since 1978, researchers have observed that the yield strength of conditioned sludge increased with the addition of polymer up to the optimum dose. Then sludge rheogram was used as a control parameter to optimize the addition of polymers, and the peak height in the shear stress vs. shear rate curve was an indication of sludge conditionablity, where the optimum polymer conditioning corresponding to the highest peak was obtained. However, few studies have addressed the effects of distinct conditioning factors on the appearance of peaks in such rheograms. In this study, the impact of factors such as high speed mixing and polymer dosing rates on the geometric and rheological characteristics of conditioned anaerobic digested sludge (ADS) with the polymer zetag7557 were investigated through the jar test method. The results showed that both the high speed mixing time and polymer dosing time had important effects on the emergence of the initial peak in test curves obtained using the Haake RV20 and Flokky rheometers for evaluation of conditioned ADS. A high speed mixing time within 60 s or a polymer dosing time of 5 s was sufficient for observation of the initial peak in flow curves, and both peak height and area decreased as the high speed mixing times were prolonged in most cases in this study. As same as the high speed mixing time, the extension of zetag7557 dosing time can also lead to the gradual decrease in the initial peak size of test curves, and form small aggregates with a decrease in two-dimensional fractal dimensions (D2). Although the initial peak in the test curves was observed when high speed mixing intensities increased up to 300 rpm, there were several differences in the peak height and area observed on the Haake RV20 test rheograms and Floccky test curves. In addition, a high speed mixing intensity of 300 rpm was found to lead to the formation of smaller and less compact aggregates than other mixing intensities. All of the rheological and geometric parameters were somewhat correlated with fractal dimension-D2P (based on regression analysis of the logarithmics of area and perimeter). However, D2L(based on regression analysis of the logarithmics of area and maximum diameter) did not show good correlation with any other parameters. The median diameters of the aggregates were well correlated with one-dimensional fractal dimensions (D1). © 2010 Elsevier Ltd.

Fan K.,Beijing Forestry University
Journal of Convergence Information Technology | Year: 2011

Current e-commerce application in agriculture in China was investigated and a simple application model of e-agriculture in China was proposed. This paper investigates the services provided by different e-commerce enterprises including B2B service providers (third-party platform) and B2C companies (e-shop), and proposes classification of the services according to 4C strategies for the first time. The main findings include that the third-party platform in B2B and e-shop in B2C are used more widely in e-agriculture and the vertical B2B platform is developing more slowly than the level B2B platform. In addition, e-agriculture in animal disease, fruit and fisheries scopes are developing laggardly. Many important services are not available in all e-agriculture platforms, including international trade platform, consulting and research, personalized recommendation, and so on. The findings of the study are expected to assist e-agriculture service providers and companies to understand current e-agriculture in China and to promote their improving services.

Sun Y.,China Agricultural University | Cheng Q.,China Agricultural University | Lin J.,Beijing Forestry University | Schellberg J.,University of Bonn | Schulze Lammers P.,University of Bonn
Journal of Plant Nutrition and Soil Science | Year: 2013

Precision-farming applications are mainly based on site-specific information of soil properties at the field scale. For this purpose, a number of novel sensor techniques have been developed but not intensively tested under different field conditions. This study presents a combined application of a self-developed dual-sensor vertical penetrometer (DVP) for measuring volumetric soil water content (VSWC) and cone index (CI), and an EM38 for soil apparent electrical conductivity (ECa) in a pasture (1.4 ha). To verify the feasibility of the DVP for interpreting the depth-specific information in the field, not only the soil physical properties and their geographical coordinates were measured, but also geo-referenced yield data were collected. We found that the yield pattern was quite similar to the soil water-content pattern of each layer (layer-1: 5-15cm; layer-2: 15-25cm, layer-3: 25-35cm) and ECa pattern. Using the map-based comparisons in conjunction with the statistical analyses, the effect of each measured soil physical property (VSWC, CI, and ECa) on the yield was investigated. The regression between the yield and VSWC at each layer fitted a quadratic equation (R2 = 0.515 at 5-15cm; R2 = 0.623, at 15-25cm; R2 = 0.406 at 25-35cm). The negative correlation between yield and CI at each layer fitted a linear model with R2 ≥ 0.510. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wang Z.,Yale University | Nilsson R.H.,Gothenburg University | Nilsson R.H.,University of Tartu | Lopez-Giraldez F.,Yale University | And 4 more authors.
PLoS ONE | Year: 2011

An abundance of novel fungal lineages have been indicated by DNA sequencing of the nuclear ribosomal ITS region from environmental samples such as soil and wood. Although phylogenetic analysis of these novel lineages is a key component of unveiling the structure and diversity of complex communities, such analyses are rare for environmental ITS data due to the difficulties of aligning this locus across significantly divergent taxa. One potential approach to this issue is simultaneous alignment and tree estimation. We targeted divergent ITS sequences of the earth tongue fungi (Geoglossomycetes), a basal class in the Ascomycota, to assess the performance of SATé, recent software that combines progressive alignment and tree building. We found that SATé performed well in generating high-quality alignments and in accurately estimating the phylogeny of earth tongue fungi. Drawing from a data set of 300 sequences of earth tongues and progressively more distant fungal lineages, 30 insufficiently identified ITS sequences from the public sequence databases were assigned to the Geoglossomycetes. The association between earth tongues and plants has been hypothesized for a long time, but hard evidence is yet to be collected. The ITS phylogeny showed that four ectomycorrhizal isolates shared a clade with Geoglossum but not with Trichoglossum earth tongues, pointing to the significant potential inherent to ecological data mining of environmental samples. Environmental sampling holds the key to many focal questions in mycology, and simultaneous alignment and tree estimation, as performed by SATé, can be a highly efficient companion in that pursuit. © 2011 Wang et al.

Liquefied wood-based activated carbon fibers (LWACF) were prepared from liquefied wood-based precursors (LWP) and liquefied wood-based carbon fibers. Microstructure and properties of LWACF were studied using analysis of X-ray diffraction, nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and a microtensile tester. It was found that LWACF prepared from LWP (LWACF1) could form a larger crystal size and denser graphite-like structure than those prepared from LWCF (LWACF2). However, for LWACF2, micropores were more numerous and average micropore width was larger, leading to the conclusion that LWACF2 had smaller diameter and lower mechanical properties than LWACF1 and that the burn-off value of LWACF2 was larger than that of LWACF1. Furthermore, excess amounts of element carbon (C) and C bonded to oxygen-containing functions were found on the surface of LWACF2. In conclusion, postcarbonization could damage the graphite-like structure, resulting in expanded micropores and impaired mechanical properties. Postcarbonization brought about an increase in the amount of element C and in the relative content of C bonded to oxygen-containing functions. © 2014 by the Society of Wood Science and Technology.

Li J.,Fudan University | Xia R.,Fudan University | McDowall R.M.,NIWA - National Institute of Water and Atmospheric Research | Lopez J.A.,University of Alaska Fairbanks | And 3 more authors.
Molecular Phylogenetics and Evolution | Year: 2010

This study examines phylogenetic placement of the enigmatic Western Australian Lepidogalaxias, and extends previous studies by including eight new taxa to enable re-examination phylogenetic relationships of lower euteleostean fishes at the ordinal level, based on mitochondrial genomes from 39 ingroup taxa and 17 outgroups. Our results suggest that Lepidogalaxias occupies a basal position among all euteleosts, in contrast with earlier hypotheses that variously suggested a closer relationship to esocid fishes, or to the galaxiid Lovettia. In addition our evidence shows that Osmeriformes should be restricted Retropinnidae, Osmeridae, Plecoglossidae and Salangidae. This reduced Osmeriformes is supported in our results as the sister group of Stomiiformes. Galaxiidae, which is often closely linked to Osmeriformes, emerges as sister group of a combined Osmeriformes, Stomiiformes, Salmoniformes, Esociformes and Argentiformes, and we give Galaxiiformes the rank of order to include all remaining galaxioid fishes (Galaxias and allied taxa, Aplochiton and Lovettia). Our results also support a sister group relationship between Salmoniformes and Esociformes, which are together the sister group of Argentiniformes. © 2010 Elsevier Inc.

Yang Z.,Beijing Forestry University
Behavioural and Cognitive Psychotherapy | Year: 2013

Background: Studies have shown that the intolerance of uncertainty may play a key role in the aetiology and maintenance of worry and generalized anxiety disorder. Aims: This study investigated the psychometric properties of the Chinese version of Intolerance of Uncertainty Scale (IUS), which had already been validated in French and English versions. Method: In a large college student sample (N = 940), the factor analysis and regression analyses were performed on the IUS. Results: The IUS had excellent internal consistency (α = 0.90) and good test-retest reliability (r = 0.75) over a 5-week period. Factor analysis showed that the IUS had a four-factor solution. Finally, the regression analysis demonstrated that IU contributed significantly to worry, after controlling for demographic variables and levels of anxiety and depression. Conclusions: The Chinese version of the IUS was a sound scale for assessing IU and the intolerance of uncertainty was an important influencing factor on worry. Copyright © British Association for Behavioural and Cognitive Psychotherapies 2012.

Xing Z.-P.,Heilongjiang University | Sun D.-Z.,Heilongjiang University | Yu X.-J.,Heilongjiang University | Zou J.-L.,Heilongjiang University | Zhou W.,Beijing Forestry University
Environmental Progress and Sustainable Energy | Year: 2014

A continuously operated laboratory scale anaerobic and aerobic moving bed biofilm reactors (MBBRs) combined with O3/H2O2 process was experimented for antibiotic fermentation-based pharmaceutical wastewater. The experimental results indicated that 26.6% of chemical oxygen demand (COD) was removed, and 931.75 mg/L of volatile fatty acids (VFAs) was produced under the optimum conditions of the anaerobic MBBR at an influent pH of 6.5, hydraulic retention time (HRT) of 12 hr and organic loading rate (OLR) of 13 kg COD/(m3·d) for the hydrolysis/acidification process. In addition, 91.0% of COD was removed at 1.5 m3/h of aeration rate with the aerobic MBBR. The shape of bacteria inside the bio-carriers was characterized by a scanning electron microscope. The anaerobic MBBR bacteria were observed as long bacilli, and the aerobic MBBR bacteria were observed as mainly cocci and short bacilli. Finally, the residual non-biodegraded pollutants were mineralized by O3/H2O2 oxidation with 0.5 of H2O2/O3 molar ratio and 15 min of reaction time. The total removal efficiencies of COD and color reached 99.2 and 98.7%, respectively. Thus, this method might offer an effective way to treat wastewater from the pharmaceutical industry. © 2013 American Institute of Chemical Engineers.

Zhu H.,Tsinghua University | Zhu H.,Beijing Forestry University | Wen X.,Tsinghua University | Huang X.,Tsinghua University
Journal of Membrane Science | Year: 2010

Factors associated with membrane organic fouling during secondary effluent organic matter (EfOM) microfiltration were explored. Ozone application and its effects on EfOM characteristics along with pre-ozonation effects on EfOM membrane fouling were also studied. Microfiltration tests with EfOM and its hydrophilic and hydrophobic fractions show that hydrophilic substances (HIS) have a stronger fouling potential. This is explained through analysis that reveals HIS possessing a higher macromolecular and carboxylic group content along with higher soluble microbial products (SMP) or SMP-like substances. Adhesion forces directly measured with atomic force spectroscopy (AFM) proved that HIS had the highest affinity to pristine and EfOM fouled membrane. Pre-ozonation effects include an increase in carboxylic and phenolic groups which may aggravate membrane fouling. However, the reduction of dissolved organic carbon (DOC) (including mineralization of small organic molecules) and breaking of large molecules are the dominant criteria for fouling reduction. © 2010 Elsevier B.V. All rights reserved.

Huang L.,CAS Institute of Geographical Sciences and Natural Resources Research | Ning Z.,Development Research Center | Zhang X.,Beijing Forestry University
Ecological Indicators | Year: 2010

The study described the uncertainties of NPP estimation due to larch defoliation by caterpillars during 2001-2004 in Northeastern China, which is an order of magnitude larger in area and severe than all previous recorded outbreaks. Using "representative needles" collected in the field, we related spectral responses and photosynthetic contents of needles to ecophysiological parameters in NPP estimation for different degrees of caterpillar damage. It is concluded that locations of reflection peaks at or near green red near-infrared wavelength moving toward long-wave direction with aggravated damage degree, which is useful to earlier prediction of caterpillar damage. Contents of chlorophyll-a reduced by 40.26, 66.29 and 86.88% for light, moderate and severe damage samples respectively compared with healthy, chlorophyll-b reduced by 20.79, 52.67 and 82.39%, and carotenoid reduced by 9.80, 45.06 and 73.15%. Estimated NDVI values decreased by 9.89-31.08, 38.16-47.47 and 61.90-66.71%, respectively. It results to the decrease of LAI by 39.76-74.34, 85.85-93.64 and 94.61-98.51%, and reduction of FPAR and APAR by 10.16-37.47, 39.21-57.24 and 63.60-80.44%. In addition, the increased minimum visible reflectance during 580-680 nm leads to the decrease of estimated aboveground biomass by 14.62, 48.86 and 56.84%, and reduction of estimated autotrophic respiration by 10.32, 39.11 and 46.95%. Ultimately, the caterpillar outbreak results to the directly underestimation of NPP by 10.01-64.63, 39.32-75.37 and 80.26-100% for light, moderate and severe samples compared with healthy. Furthermore, such impacts of forest insect disturbances should be accounted for in NPP modeling to reduce the uncertainties of estimation. © 2010 Elsevier Ltd. All rights reserved.

Wu S.,Beijing Forestry University
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2011

In the title polymeric heterometallic compound, {[Cu3Gd(C 6H4NO2)3Cl3(H2O) 2]·0.5H2O} n, comprising copper(I) and gadolinium(III) cations bridged by nicotinate (nic) ligands and chloride anions, the GdIII centers display a bicapped trigonal prismatic geometry, defined by six carboxyl-ate O atoms and two water mol-ecules. For copper(I), one Cu center is three-coordinated by three chloride ions and displays a trigonal-planar geometry; the other two Cu centers are four-coordinated and display a very distorted tetrahedral geometry. The chloride anions act in 2- and 3-bridging modes, linking the CuI ions into an infinite chain. The nic ligand exhibits a tridentate coordination mode, with the carboxyl-ate O atoms linking to two GdIII ions and the N atom linking to one CuI ion. Thus, a novel three-dimensional heterometallic coordination polymer is constructed from Gd-carboxyl-ate subunits and Cu - Cl chains. In addition, intra- and inter-molecular O - H⋯O and O - H⋯Cl hydrogen bonds are also observed within the three-dimensional structure. Topologically, the framework represents an unusual 3,6-connected (4.82)3(4 10.65) net. © 2011 International Union of Crystallography.

Li X.,CSIRO | Yang X.,CSIRO | Yang X.,Beijing Forestry University | Wu H.X.,CSIRO | Wu H.X.,Swedish University of Agricultural Sciences
BMC Genomics | Year: 2013

Background: Formation of compression (CW) and opposite wood (OW) in branches and bent trunks is an adaptive feature of conifer trees in response to various displacement forces, such as gravity, wind, snow and artificial bending. Several previous studies have characterized tracheids, wood and gene transcription in artificially or naturally bent conifer trunks. These studies have provided molecular basis of reaction wood formation in response to bending forces and gravity stimulus. However, little is known about reaction wood formation and gene transcription in conifer branches under gravity stress. In this study SilviScan® technology was used to characterize tracheid and wood traits in radiate pine (Pinus radiata D. Don) branches and genes differentially transcribed in CW and OW were investigated using cDNA microarrays.Results: CW drastically differed from OW in tracheids and wood traits with increased growth, thicker tracheid walls, larger microfibril angle (MFA), higher density and lower stiffness. However, CW and OW tracheids had similar diameters in either radial or tangential direction. Thus, gravity stress largely influenced wood growth, secondary wall deposition, cellulose microfibril orientation and wood properties, but had little impact on primary wall expansion. Microarray gene transcription revealed about 29% of the xylem transcriptomes were significantly altered in CW and OW sampled in both spring and autumn, providing molecular evidence for the drastic variation in tracheid and wood traits. Genes involved in cell division, cellulose biosynthesis, lignin deposition, and microtubules were mostly up-regulated in CW, conferring its greater growth, thicker tracheid walls, higher density, larger MFA and lower stiffness. However, genes with roles in cell expansion and primary wall formation were differentially transcribed in CW and OW, respectively, implicating their similar diameters of tracheid walls and different tracheid lengths. Interestingly, many genes related to hormone and calcium signalling as well as various environmental stresses were exclusively up-regulated in CW, providing important clues for earlier molecular signatures of reaction wood formation under gravity stimulus.Conclusions: The first comprehensive investigation of tracheid characteristics, wood properties and gene transcription in branches of a conifer species revealed more accurate and new insights into reaction wood formation in response to gravity stress. The identified differentially transcribed genes with diverse functions conferred or implicated drastic CW and OW variation observed in radiata pine branches. These genes are excellent candidates for further researches on the molecular mechanisms of reaction wood formation with a view to plant gravitropism. © 2013 Li et al.; licensee BioMed Central Ltd.

Xiao R.,Beijing Normal University | Xiao R.,Beijing Forestry University | Bai J.,Beijing Normal University | Huang L.,Beijing Normal University | And 3 more authors.
Ecotoxicology | Year: 2013

Sediments were collected from the upper, middle and lower reaches of both urban and rural rivers in a typical urbanization zone of the Pearl River delta. Six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were analyzed in all sediment samples, and their spatial distribution, pollution levels, toxicity and ecological risk levels were evaluated to compare the characteristics of heavy metal pollution between the two rivers. Our results indicated that the total contents of the six metals in all samples exceeded the soil background value in Guangdong province. Based on the soil quality thresholds of the China SEPA, Cd levels at all sites exceeded class III criteria, and other metals exhibited pollution levels exceeding class II or III criteria at both river sites. According to the sediment quality guidelines of the US EPA, all samples were moderately to heavily polluted by Cr, Cu, Ni, Pb and Zn. Compared to rural river sites, urban river sites exhibited heavier pollution. Almost all sediment samples from both rivers exhibited moderate to serious toxicity to the environment, with higher contributions from Cr and Ni. A "hot area" of heavy metal pollution being observed in the upper and middle reaches of the urban river area, whereas a "hot spot" was identified at a specific site in the middle reach of the rural river. Contrary metal distribution patterns were also observed along typical sediment profiles from urban and rural rivers. However, the potential ecological risk indices of rural river sediments in this study were equal to those of urban river sediments, implying that the ecological health issues of the rivers in the undeveloped rural area should also be addressed. Sediment organic matter and grain size might be important factors influencing the distribution profiles of these heavy metals. © 2013 Springer Science+Business Media New York.

Cheng P.,Beijing Forestry University
Journal of Theoretical and Applied Information Technology | Year: 2012

In order to improve the precision of vision inspection system for micro accessory, edge detection technique of micro accessory was studied. Firstly, the imaging features of the micro accessory inspection system were analyzed. Fraunhofer diffraction happens, because the light wave is restricted by microscope. Secondly, optical characteristics of micro images were analyzed. The gray curve of the micro image edge does not change with the different inspected accessories. The threshold function of the edge detection was put forward according to the Analysis of dividing rule diffraction fringe. Finally, the threshold function of the edge detection was applied to gauge block and pendulum block. Experimental results indicate that the maximum error of the gauge block inspection is 0.22μm and the maximum error of the pendulum block inspection is 0.28μm. The measuring precision of figures is up to sub-pixel and the measuring precision of micro accessories is up to submicron. It can satisfy the system requirements of the micro accessory inspection. © 2005 - 2012 JATIT & LLS.All rights reserved.

Fan K.,Beijing Forestry University
Advances in Information Sciences and Service Sciences | Year: 2012

A new comprehensive evaluation method is proposed to assess the credit risk of online trading company. Sometimes many companies have good online credit, but they maybe face credit crisis because of their serious financial problems. So we need to consider both online and offline credit risk. In this paper, credit risk evaluation model consisting of offline and online credit evaluation index systems is presented to determine the credibility of the e-commerce participants. The offline index includes the financial situation, internal characteristic and external condition these three major indicators, while online index consists of product, service, transport and overall credit evaluation these four major indexes. Expert assessment method and the analytic hierarchy process (AHP) are used to determine the indexes' weights and the multi-hierarchy fuzzy comprehensive evaluation method is used to calculate the credit evaluation score. Based on this credit score, we can obtain the online trading company's standard credit rating. Finally, case analysis illustrates our credit risk comprehensive evaluation method is effective and comprehensive.

da Veiga Mendonca C.,Beijing Forestry University
Forestry Studies in China | Year: 2010

A comparison of the management models of protected areas between China and the African south region allows reading and evaluating the similarities and differences in the use of management model as a management tool for protected areas and specifically some positive and negative features of the management approaches in these two regions. Previous to this study it verified the designation of protected areas as increasing at a faster rate than ever before, comparatively much faster now in China than southern Africa regions. With the aim of evaluating similarities and differences in the use of management model as a management tool for protected areas in China and southern Africa Region, both qualitative and quantitative data were collected. Qualitative data were mainly from policy documents, scientific articles and magazine reports, whereas quantitative (secondary data) statistical data from International Union for Conservation of Nature Resources (IUCN) and World Database on Protected Areas (WDPA). In view of the data sources above, the study found that in China all the protected areas are state owned whilst in southern Africa regions there are some protected areas that are privately owned; also that the models or typology of governance applied are successful for the fact that they both combine co-management or collaborative management, community-conserved areas and private protected areas that are subject to greater success and can help design planning and management than those who use exclusively government management. To this, the study concluded that the use of management model is influenced by the type of governance a country applies to its reserved areas. © 2010 Beijing Forestry University and Springer Berlin Heidelberg.

Qiao G.,Harbin Institute of Technology | Hong Y.,Harbin Institute of Technology | Sun G.,Beijing Forestry University | Yang O.,Hunan University
IEEE Sensors Journal | Year: 2013

Compared with traditional sensors powered by the grid, energy-harvesting wireless sensors have many significant advantages, especially when applied in harsh environments. A novel power supply element, i.e., concrete battery, is designed for the wireless corrosion-monitoring sensors. Then, the power generation capacity of the corrosion-sensitive materials (Mg and Zn) is verified in a series of simulated concrete pore solutions. Furthermore, the electric quantity generated during the corrosion process is analyzed in detail. The results indicate that the novel concrete batteries based on Mg or Zn materials are a promising solution for powering wireless corrosion-monitoring sensors. © 2001-2012 IEEE.

Walawage S.L.,University of California at Davis | Britton M.T.,University of California at Davis | Leslie C.A.,University of California at Davis | Uratsu S.L.,University of California at Davis | And 2 more authors.
BMC Genomics | Year: 2013

Background: Crown gall (CG) (Agrobacterium tumefaciens) and the root lesion nematodes (RLNs) (Pratylenchus vulnus) are major challenges faced by the California walnut industry, reducing productivity and increasing the cost of establishing and maintaining orchards. Current nematode control strategies include nematicides, crop rotation, and tolerant cultivars, but these methods have limits. Developing genetic resistance through novel approaches like RNA interference (RNAi) can address these problems. RNAi-mediated silencing of CG disease in walnut (Juglans regia L.) has been achieved previously. We sought to place both CG and nematode resistance into a single walnut rootstock genotype using co-transformation to stack the resistance genes. A. tumefaciens, carrying self-complimentary iaaM and ipt transgenes, and Agrobacterium rhizogenes, carrying a self-complimentary Pv010 gene from P. vulnus, were used as co-transformation vectors. RolABC genes were introduced by the resident T-DNA in the A. rhizogenes Ri-plasmid used as a vector for plant transformation. Pv010 and Pv194 (transgenic control) genes were also transferred separately using A. tumefaciens. To test for resistance, transformed walnut roots were challenged with P. vulnus and microshoots were challenged with a virulent strain of A. tumefaciens. Results: Combining the two bacterial strains at a 1:1 rather than 1:3 ratio increased the co-transformation efficiency. Although complete immunity to nematode infection was not observed, transgenic lines yielded up to 79% fewer nematodes per root following in vitro co-culture than untransformed controls. Transgenic line 33-3-1 exhibited complete crown gall control and 32% fewer nematodes. The transgenic plants had thicker, longer roots than untransformed controls possibly due to insertion of rolABC genes. When the Pv010 gene was present in roots with or without rolABC genes there was partial or complete control of RLNs. Transformation using only one vector showed 100% control in some lines. Conclusions: CG and nematode resistance gene stacking controlled CG and RLNs simultaneously in walnuts. Silencing genes encoding iaaM, ipt, and Pv010 decrease CG formation and RLNs populations in walnut. Beneficial plant genotype and phenotype changes are caused by co-transformation using A. tumefaciens and A. rhizogenes strains. Viable resistance against root lesion nematodes in walnut plants may be accomplished in the future using this gene stacking technology. © 2013 Walawage et al.; licensee BioMed Central Ltd.

Chen J.Y.,Beijing Forestry University
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji | Year: 2011

To provide initial value for population restoration and management of wolves (Canis lupus) in the wild, line transect survey and fecal analysis method were used to study the population ecology of wolf at Saihanwula National Nature Reserve, Inner Mongolia. The results revealed that the population number was at least seven within the reserve and population density was 4.18+/-2.88 individual per 100 km2. The wolf population was mainly distributed in Shengshan and Qinyunshan core areas; active sites appeared mostly along mountain ridges, roads and valleys at Shengshan and mountain ridges at Qinyunshan. Hare (Lepus capensis) and plants occurred frequently in the food composition of wolf scats. Food types varied between years but not seasons (Winter-Spring and Summer-Autumn).

Dai Y.-C.,CAS Shenyang Institute of Applied Ecology | Cui B.-K.,Beijing Forestry University
Fungal Biology | Year: 2011

A giant polypore, Fomitiporia ellipsoidea, was found in Hainan Island in southern China. It was 20y old, and its estimated volume was 409 000-525 000 cm3 and weight was 400-500kg. This is the first report of the largest fungal fruiting body both in volume and weight. © 2011 British Mycological Society.

Zhang A.-P.,South China University of Technology | Liu C.-F.,South China University of Technology | Sun R.-C.,South China University of Technology | Sun R.-C.,Beijing Forestry University
Industrial Crops and Products | Year: 2010

The sequential three-step extraction procedure performed on fast-growing poplar, Triploid of Populus tomentosa Carr., with 96:4 dioxane:water, 50:50 dioxane:water and 80:20 dioxane:water containing 1% NaOH at 85 °C yielded 11.41% lignin and 14.78% hemicelluloses based on poplar dry mass. The structural features of the three isolated lignin fractions were comparatively examined by nitrobenzene oxidation, FT-IR, 31P NMR and 1H-13C 2D NMR spectroscopies. The results showed that the three lignin fractions, isolated sequentially with neutral and alkaline dioxane, were all GSH-type lignin. The ratio of non-condensed syringyl to guaiacyl was 2.7, 3.2, and 1.3 in the 96:4 dioxane:water, 50:50 dioxane:water, and alkaline dioxane lignin extracts, respectively. The contents of phenolic hydroxyl groups in the three lignin fractions obtained from 31P NMR spectra were 1.2, 0.7, and 0.87 mmol/g, respectively. The results also indicated that the 50:50 dioxane:water lignin extracts contained a relatively higher amount of aliphatic hydroxyls and a lower amount of non-condensed syringyl hydroxyl groups than the other two fractions. © 2009 Elsevier B.V. All rights reserved.

Zhao J.P.,Chinese Academy of Forestry | Zhao J.P.,Agricultural University of Hebei | Zhao J.P.,Beijing Forestry University | Su X.H.,Chinese Academy of Forestry
Planta | Year: 2010

Some pathogenesis-related proteins (PR proteins) are subject to positive selection, while others are under negative selection. Here, we report the patterns of molecular evolution in thaumatin-like protein (TLP, PR5 protein) genes of Populus trichocarpa. Signs of positive selection were found in 20 out of 55 Populus TLPs using the likelihood ratio test and ML-based Bayesian methods. Due to the connection between the acidic cleft and the antifungal activity, the secondary structure and three-dimensional structure analyses predicted antifungal activity β-1,3-glucanase activities in these TLPs. Moreover, the coincidence with variable basic sites in the acidic cleft and positively selected sites suggested that fungal diseases may have been the main environmental stress that drove rapid adaptive evolution in Populus. © 2010 Springer-Verlag.