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Photosynthetic performance of switchgrass and its relation to field productivity：A three-year experimental appraisal in semiarid Loess Plateau

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Journal of Integrative Agriculture 2017年第6期16卷 1227-1235页

作者： GAO Zhi-juan LIU Jin-biao AN Qin-qin WANG Zhi CHEN Shao-lin XU Bing-cheng State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Yangling 712100 P. R. China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 P. R. China College of Life Science Northwest A&F University Yangling 712100 P.R. China

To reveal photosynthetic characteristics and biomass yield is important for evaluating introduced species adaptation to local environments. A field experiment was conducted over three consecutive years（2011–2013） to evaluate photosynthetic characteristics, soil water content, aboveground biomass accumulation, and water use efficiency（WUE） in switchgrass（Panicum virgatum L.） populations exposed to three row spacing（20, 40 and 60 cm） treatments in two growth months（June and August） on the semiarid Loess Plateau of China. Results indicated that net photosynthetic rate（Pn）, transpiration rate（Tr）, instantaneous water use efficiency（WUEi） and plant height of switchgrass showed an increased trend, but aboveground biomass production and WUE showed an decreased trend with enlarged row spacings over the three years. The maximum daily mean Pn values（17.9, 18.4 and 19.7 μmol CO2 m^（-2） s^（-1）） were observed in 2011, and the highest aboveground biomass production（67 771.8, 6 976.8 and 6 609.2 kg ha^（-1）） were recorded in 2012 for 20, 40 and 60 cm, respectively. A close correlation between tiller numbers and aboveground biomass production（r=0.907） was observed. Pn was positively and significantly correlated with biomass per tiller, but it showed a negative correlation with aboveground biomass production. Our results confirm that wide row spacing is beneficial for single plant development, while narrow row spacing favors biomass production and water use of switchgrass in the region. It also implies that single leaf growth and performance could explain the switchgrass community density differences, while fails to account for the aboveground biomass production.

关键词： switchgrass photosynthesis row spacing biomass production water use efficiency

Fabrication and characteristics of nitrogen-doped nanocrystalline diamond/p-type silicon heterojunction

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Nano-Micro Letters 2010年第1期2卷 56-59页

作者： D.Lu H.D.Li S.H.Cheng J.J.Yuan X.Y.Lv State Key Laboratory of Superhard Materials Jilin University

Nitrogen-doped nanocrystalline diamond films(N-NDFs)have been deposited on p-type silicon(Si)by microwave plasma chemical vapor *** reaction gases are methane,hydrogen,and nitrogen without the conventional argon(Ar).The N-NDFs were characterized by X-ray diffraction,Raman spectroscopy,and scanning electron *** grain sizes are of 8~10 nm in *** N-NDF shows n-type behavior and the corresponding N-NDF/p-Si heterojunction diodes are realized with a high rectification ratio of 102 at^7.8 V,and the current density reaches to1.35 A/cm2 at forward voltage of 8.5 *** findings suggest that fabricated by CH_4/H_2/N_2 without Ar,the N-NDFs and the related rectifying diodes are favorable for achieving high performance diamond-based optoelectronic devices.

关键词： Nanocrystalline diamond film Chemical vapor deposition Nitrogen doped Heterojunction diodes Current-voltage characteristics

Using maximum likelihood method to detect adaptive evolution of HCV envelope protein-coding genes

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Chinese Science Bulletin 2006年第18期51卷 2236-2242页

作者： ZHANG Wenjuan ZHANG Yuan ZHONG Yang School of Life Sciences Fudan University Shanghai 200433 China Shanghai Center for Bioinformation Technology Shanghai 201203 China

Nonsynonymous-synonymous substitu- tion rate ratio (dN/dS) is an important measure for evaluating selective pressure based on the pro- tein-coding sequences. Maximum likelihood (ML) method with codon-substitution models is a powerful statistic tool for detecting amino acid sites under positive selection and adaptive evolution. We ana- lyzed the hepatitis C virus (HCV) envelope pro- tein-coding sequences from 18 general geno/ sub- types worldwide,and found 4 amino acid sites under positive selection. Since these sites are located in different immune epitopes,it is reasonable to antici- pate that our study would have potential values in biomedicine. It also suggests that the ML method is an effective way to detect adaptive evolution in virus proteins with relatively high genetic diversity.

关键词：适应进化阳性选择氨基酸肝炎病毒包膜蛋白 HCV

Diagnosis of soft faults in analog integrated circuits based on fractional correlation

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Journal of Semiconductors 2012年第8期33卷 117-122页

作者：邓勇师奕兵张伟 School of Automation Engineering University of Electronic Science and Technology of China School of Electronics and Information Engineering Southwest Petroleum University

Aiming at the problem of diagnosing soft faults in analog integrated circuits, an approach based on fractional correlation is proposed. First, the Volterra series of the circuit under test （CUT） decomposed by the fractional wavelet packet are used to calculate the fractional correlation functions. Then, the calculated fractional correlation functions are used to form the fault signatures of the CUT. By comparing the fault signatures, the different soft faulty conditions of the CUT are identified and the faults are located. Simulations of benchmark circuits illustrate the proposed method and validate its effectiveness in diagnosing soft faults in analog integrated circuits.

关键词： analog circuits soft faults fault diagnosis Volterra series fractional correlation

Preparation and characterization of organic pigments and their fluorescence properties depending on bulk structure

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Journal of Materials Science & Technology 2018年第11期34卷 2218-2224页

作者： Jie Du Rong Yang Changqing Fang Xing Zhou Shaofei Pan Wanqing Lei Jian Su Youliang Cheng Donghong Liu School of Mechanical and Precision Instrument Engineering Xi'an University of Technology Faculty of Printing Packaging Engineering and Digital Media TechnologyXi'an University of Technology Fuli Institute of Food Science Zhejiang University School of Materails Science and Engineering Xi'an University of Technology

Fluorescent pigments, based on the optical or electrooptical properties of dyes, are the main component in fluorescent coatings and inks. In this study, three kinds of dyes（Rhodamine B, Light Green SF Yellowish, Coumarin） with four different ratios（2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%） were employed as luminophor,and the melamine-formaldehyde（MF） resin was used as curing resin to prepare fluorescent pigments in different color. Fourier transform infrared spectroscopy and X-ray diffractometry were carried out to analyze the structure of the fluorescent pigments. Scanning electron microscopy and particle size distribution were used to present the morphology of fluorescent pigments. UV–vis and fluorescence spectrum were used to demonstrate the optical properties. It can be concluded that, coumarin pigments possessed consecutive structure in MF resin while rhodamine B might be the best for the preparation of printing inks among the three kinds of dyes from the view of particle size. The TG results presented that all the pigments showed good thermal stability, which might possess potential application in high speed printing industry.

关键词： Fluorescein Microstructures and properties Optical properties Thermal properties

Nanomaterials Applied in Asphalt Modification:A Review

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Journal of Materials Science & Technology 2013年第7期29卷 589-594页

作者： Changqing Fang Ruien Yu Shaolong Liu Yan Li College of Printing and Packing Engineering Xi'an University of Technology School of Mechanical and Precision Instrument Engineering Xi'an University of Technology

Nanotechnology has been gradually penetrated into the field of asphalt modification. Seemingly magic effects of nanomaterials have now been brought to improve the performance of asphalt. To demonstrate many of the prospective applications, researchers have conducted a series of positive and effective efforts dealing with the preparation of modified asphalt to demonstrate the mechanism of modification and the resultant improvement in performance. In this review, various nanomaterials used in asphalt modification are initially presented, followed by the methods employed to modify the asphalt with these materials and finally the effects of nanomaterials on the performance of base asphalt are presented and the modification mechanisms are discussed. Based on the current research results, the influence of preparation process parameters on the compatibility of every phase in the modified asphalt and the stability of the modified asphalt system are described. Finally, the development trend of the topic field is projected.

关键词： Nanomatcriais Asphalt Modification Composites Properties

Correlation of Raw Materials and Waterborne Polyurethane Properties by Sequence Similarity Analysis

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Journal of Materials Science & Technology 2016年第7期32卷 687-694页

作者： Xing Zhou Changqing Fang Jing Chen Shujuan Li Yan Li Wanqing Lei School of Mechanical and Precision Instrument Engineering Xi'an University of Technology Xi'an 710048 China Faculty of Printing Packaging Engineering and Digital Media Technology Xi'an University of Technology Xi'an 710048 China Wuxue High School Hubei 435400 China

Anionomer-type waterborne polyurethane dispersions （PUDs） were obtained from poly （propylene glycol）（PPG）, isophorone diisocyanate （IPDI） and dimethylolpropionic acid （DMPA） through a modified prepolymer isocyanate process. Two series of polyurethanes were prepared （Groups A and B） and a new prediction model based on grey relational analysis is introduced to predict the impact order of raw materials on several properties, such as solids content, viscosity, acid number and electrolytic stability of polyure- thanes. It is found that the model can successfully predict the impact of raw materials on the properties through the designed demonstration experiments. Furthermore, the results of the prediction model show that DMPA plays a key role in viscosity, oartial acid values and electrolvtic stability.

关键词： Dispersion Material properties Model Polyurethane(PU) Stability Synthesis

Humic acid transport in saturated porous media:Influence of flow velocity and influent concentration

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Journal of Environmental Sciences 2014年第12期26卷 2554-2561页

作者： Xiaorong Wei Mingan Shao Lina Du Robert Horton State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Department of Agronomy Iowa State University Ames IA 50011 USA

Understanding the transport of humic acids（HAs） in porous media can provide important and practical evidence needed for accurate prediction of organic/inorganic contaminant transport in different environmental media and interfaces. A series of column transport experiments was conducted to evaluate the transport of HA in different porous media at different flow velocities and influent HA concentrations. Low flow velocity and influent concentration were found to favor the adsorption and deposition of HA onto sand grains packed into columns and to give higher equilibrium distribution coefficients and deposition rate coefficients, which resulted in an increased fraction of HA being retained in ***, retardation factors were increased and the transport of HA through the columns was delayed. These results suggest that the transport of HA in porous media is primarily controlled by the attachment of HA to the solid matrix. Accordingly, this attachment should be considered in studies of HA behavior in porous media.

关键词： Attachment Flow velocity Humic acid Initial concentration Porous media Transport

Effect of Preparation Temperature on the Aging Properties of Waste Polyethylene Modified Asphalt

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Journal of Materials Science & Technology 2015年第3期31卷 320-324页

作者： Changqing Fang Mengya Zhang Ruien Yu Xiaolong Liu School of Printing and Packing Engineering Xi'an University of Technology

In this study, waste polyethylene(WPE) was used as a modifier for base asphalt. In our previous studies,we have examined a variety of polymer modifiers for asphalt. By contrast, little research has focused on the preparation process, such as preparation time, preparation temperature and shear rate. The effect of preparation temperature on aging properties of WPE-modified asphalt was investigated in this work. The experimental materials were characterized by infrared spectroscopy(IR), thermo-gravimetric analysis(TG), and differential scanning calorimetry(DSC). The physical properties were determined by conducting asphalt penetration, softening point and ductility tests. The results show that increasing the preparation temperature results in an increased softening point of WPE-modified asphalt while decreased penetration and ductility. In addition, this variation was accentuated by aging the experimental materials. The modification process of WPE is a physical process. During the asphalt modification process, the WPE aged as the preparation temperature increased. The results revealed that 190 C is the most suitable preparation temperature, and the post aged asphalt demonstrated improved high temperature stability.

关键词： Waste plastics Characterization Temperature