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Chinese Chemical Letters 2009年第12期20卷 1478-1482页

作者： Jin Nan wang Ai Min li yang Zhou li Xu State Key Laboratory of Pollution Control and Resource Reuse & School of the Environment Nanjing University Nanjing 210093 China

In this paper, humic acid （HA） was ultra-filtered into different molecular weight sections and was characterized by multielement analysis, UV254/TOC, FT-IR and three-dimensional fluorescence spectrometric. Since humic acids of different molecular weights have different hydrophilic and molecular size, the maximum adsorption capacity of basic ion exchange resins appears on the humic acid whose molecular weight ranges from 6000 to 10,000 Da.

关键词： Humic acid Molecular weight Basic ion exchange resin Adsorption

ANALYTICAL AND NUMERICAL SOLUTIONS FOR THE FLOW IN MICROTUBE WITH THREE-DIMENSIONAL CORRUGATED SURFACE,PART 1:STEADY FLOW

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Journal of Hydrodynamics 2010年第5期22卷 647-656页

作者： wang Hao-li yang Meng wang Yuan College of Metrological Technology and Engineering China Jiliang University Hangzhou 310018China Department of Fluid Engineering School of Energy and Power Engineering Xi＇an Jiaotong University Xi＇an710049 China

The influences of three-dimensional corrugated wall on the fully-developed steady no-slip flows in microtube are studied by analytical and numerical methods in this article. Detailed analytical solutions for the space-averaged equations and the numerical method for the solutions of the disturbance equations are given. An iterative arithm of coupled equations with respect to space-averaged velocities and disturbance velocities is suggested. The study shows that a three-dimensional subsidiary stress layer exists in the near-wall region. The relative roughness, wavenumber and Reynolds number are three important parameters influencing the subsidiary stresses and the space-averaged pressure drop. The space-averaged pressure drop subject to an invariable flow rate mainly depends on the position of datum surface. When the datum surface is taken at the balance position of wall function, the value of pressure drop is determined by the dynamic characteristics of the flow.

关键词： microtube three-dimensional corrugated surface space-averaged method subsidiary stress

X-ray Crystal Structure and Characterization of Tetra-vanadyl Capped Highly Reduced Polyoxometalate Anion [PMo_5~ⅥMo_7~ⅤO_(40)(V~ⅣO)_4]^(2-)

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Chemical Research in Chinese Universities 2006年第1期22卷 17-20页

作者： CHANG Song QIN Chao wang Xin-long li yang-guang wang En-bo Institute of Polyoxometalate Chemistry Faculty of Chemistry Northeast Normal University Changchun 130024 P. R. China

A novel polyoxometalate [H3O][PMo5^ⅥMo7^ⅤO40 （V^ⅣO）4]·6Py （Py = pyridine） was synthesized and characterized by IR spectrometry, TG and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group（C2/m） with α=1.3680（3） nm, b=2.1740（4） nm, c=1.1630（2） nm, β= 118.62（3）°, V= 3. 0362 （10） nm^3, Z = 2, and Rt （wR2） = 0. 0772 （0. 2312）. The compound contains a highly reduced vanadylpoly-molybdophosphate polyoxometalate anion with a four-capped structure. The four {VO} units cap four opposite pits of the pseudo-Keggin core {PMo12O40}.

关键词： Highly reduced polyoxometalate anion Hydrothermal synthesis Four-capped Pseudo-Keggin core

β-Cyclodextrin functionalized graphene oxide： an efficient and recyclable adsorbent for the removal of dye pollutants

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Frontiers of Chemical Science and Engineering 2015年第1期9卷 77-83页

作者： Shanshan wang yang li Xiaobin FAN Fengbao ZHANG Guoliang ZHANG Department of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

A novel method for the preparation of β- cyclodextrin grafted graphene oxide （GO-β-CD） has been developed. The GO-β-CD was characterized by Fourier transform infrared spectroscopy, 13C NMR spectroscopy, Raman spectroscopy and thermogravimetric analysis. The ability of GO-β-CD to remove fuchsin acid from solution was also studied. The GO-β-CD had an excellent adsorption capacity for fuchsin acid and could be recycled and reused. The adsorption capacities of GO-β-CD for other dye pollutants such as methyl orange and methylene blue were also investigated. The absorption capacities for the three dyes are in the order： fuchsin acid 〉 methylene blue 〉 methyl orange.

关键词： graphene oxide β-cyclodextrin adsorptioncapacity recycle

Theoretical Study on the Tautomerization Reaction of Formamide to Formamidic Acid Encapsulated in a Nano-sized Molecular Container

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Chemical Research in Chinese Universities 2009年第1期25卷 102-107页

作者： wang Xiu-li yang Zuo-yin wang Ju ZHANG Jing-chang CAO Wei-liang State Key Laboratory of Chemical Resource Engineering Faculty of Science Beijing University of Chemical Technology Beoing 100029 P. R. China

The hybrid calculations with ONIOM（B3LYP/6-31G＊：AM1） method were carried out on the tautomerization reaction of formamide to formamidic acid in the microcontainer-encapsulated state. The free-state tautomerization process was also investigated with B3LYP/6-31G＊＊//B3LYP/6-31G＊ method for the purpose of comparison. Bare tautomerization, H20-assisted（single-H20 or multiple-HaO） and self-assisted mechanisms were all taken into consideration for the encapsulated state. The results show that only bare tautomerization and single-H2O catalysis mechanisms are possible to the encapsulated formamide tautomerization owing to the container＇s size confinement effect. Geometrical changes in the complexed container and guest molecules are discussed to deeply understand the complex＇s structural properties. The bare tautomerization barrier in the encapsulated state increases by 23.826 kJ/mol, accounting for 12% of the corresponding total energy barrier in the free state, and the increased values for the single-H2O catalysis process are 12.958 kJ/mol, accounting for 16% of the corresponding total energy barrier, respectively. This finding suggests that the encapsulation can make the tautomerization process slightly difficult.

关键词： Formamide Tautomerization ONIOM calculations Host-guest complex

Characterization of a Novel Mesophilic Bacterial Amylase Secreted by ZW2531-1, a Strain Newly Isolated from Soil

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Chemical Research in Chinese Universities 2009年第2期25卷 198-202页

作者： wang yang li Fan GAO Chao-hui ZHANG Ying-Jiu Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education Jilin University Changchun 130021 P. R. China

A novel mesophilic bacterial amylase, named oligosaccharide-producing multifunctional amylase（OPMA）, was discovered and characterized. OPMA is an extracellular enzyme secreted by ZW253 1-1, a strain newly isolated from Chinese soil. It could be purified to homogeneity from the culture supernatant of ZW2531-1 by 30%-60% saturated ammonium sulfate precipitation, followed by twice Sephadex gel filtration chromatography. OPMA is a 66 kDa protein based on SDS-PAGE and has an isoelectric point（p/） at pH=5.3 by Isoelectric focusing electrophoresis（WE）. It only catalyzes the degradation of starch, rather than other alpha-l,4- and/or 1,6-glucan polysaccbarides such as fl-cyclomaltodextrin and pullulan. OPMA degraded starch to produce several oligosccharides including maltose, maltotriose, and isomaltotriose as the major end-products, and perhaps other oligosaccharides such as isomalto- tetraose, rather than glucose. OPMA exhibited optimal catalytic activity at a reaction temperature of 50 ℃ and pH=6.0, as determined by orthogonal test. Under the optimal reaction conditions, purified OPMA bad a specific activity of 13.75 U/rag. These findings suggest that OPMA could be used for the production of some oligosaccharides beneficial to the food industry and medicine.

关键词： Amylase Bacterium Oligosaccharide Purification Starch

Electron-electron interactions in monolayer graphene quantum capacitors

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Nano Research 2013年第8期6卷 619-626页

作者： Xiaolong Chen lin wang Wei li yang wang Zefei Wu Mingwei Zhang Yu Han Yuheng He Ning wang Department of Physics and the William Mong Institute of Nano Science and Technology Hong Kong University of Science andTechnology Hong Kong S.A.R. China

We demonstrate the effects of electron-electron （e-e） interactions in monolayer graphene quantum capacitors. Ultrathin yttrium oxide showed excellent per-formance as the dielectric layer in top-gate device geometry. The structure and dielectric constant of the yttrium oxide layers have been carefully studied. The inverse compressibility retrieved from the quantum capacitance agreed fairly well with the theoretical predictions for the e--e interactions in monolayer graphene at different temperatures. We found that electron-hole puddles played a significant role in the low-density carrier region in graphene. By considering the temperature-dependent charge fluctuation, we established a model to explain the round-off effect originating from the e-e interactions in monolayer graphene near the Dirac point.

关键词： graphene e-e interaction inverse compressibility quantum capacitance charge fluctuation electron-hole puddles

Preliminary Study on Spatial Variability and Distribution of Soil Available Microelements in Pinggu County, Beijing, China

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Agricultural Sciences in China 2008年第10期7卷 1235-1244页

作者： wang Shu-ying YU Tong-quan wang Jian-li yang liu yang Kai LU Ping New Technological Laboratory in Agriculture Application in Beijing Beijing University of Agriculture Beijing 102206 RR.China

The objectives of this study were to explore the spatial distribution of soil available microelements and to provide a firm foundation for scientifically formulated fertilizer. 1 076 soil samples were collected from Pinggu County of Beijing, China, and the contents of available Cu, Zn, Fe, and Mn in topsoil （0-20 cm） and subsoil （20-40 cm） were analyzed respectively. Descriptive statistics and geostatistics were used to analyze the data. The mean values of topsoil available Cu, Zn, Fe, and Mn were 1.96, 2.51, 17.32, and 10.91 mg kg^-1, respectively, which were at medium or at slightly above medium level. The topsoil content of the soil available microelements was more than that of subsoil. The result of semivariance analysis showed that the topsoil available Fe and Mn were spatially correlated at a larger distance of 21.6 and 45.3 km, and the available Cu and Zn were at a shorter distance of 3.1 and 2.9 km, respectively. The subsoil spatial correlation distances were obviously different from the topsoil, which were in the order of available Mn 〉 Cu 〉 Zn = Fe. The Kriging method was applied to calculate the unobserved points and was used to generate the contour map. The results showed that the structural factors, such as topology, soil types, and soil properties, were the main factors influencing the spatial distribution of topsoil available Fe and Mn. Topsoil available Cu and Zn contents were mainly affected by land use, and their contents in orchard and in vegetable land were greatly higher than in field. The spatial distribution of subsoil microelements was similar to that of the topsoil, which exhibited vertical distribution patterns. Fertilizer and pesticide application resulted in the higher contents of available Cu and Zn in Pinggu County. The higher content of available Zn is potentially harmful to soil environmental quality, which should be inspected.

关键词： soil available microelements semivariance spatial variability

Distribution and mapping of temperate savanna in the sandy lands of eastern China

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Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya li Feng wang Tao DUAN Kaijie yang Bin yang Chunmei wang Xin TIAN Qi LU Institute of Ecological Conservation and Restoration Institute of Desertification StudiesChinese Academy of ForestryBeijing100091China Institute of Desertification Institute of Desertification StudiesChinese Academy of ForestryBeijing100091China Institute of Great Green Wall Bayan Nur015200China Satellite Application Centre for Ecology and Environment MEEBeijing100094China Institute of Microelectronics Chinese Academy of SciencesBeijing100029China Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijing100091China

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution(VHR)unmanned aerial vehicle(UAV)and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover(FWVC)and fractional herbaceous vegetation cover(FHVC)in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error(RMSE)values for the FWVC and FHVC models were 10.69%and 11.67%,and the R^(2)values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10^(6)*** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy Land a

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

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Sulfur atom occupying surface oxygen vacancy to boost the charge transfer and stability for aqueous Bi2O3 electrode

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Journal of Energy Chemistry 2025年第2期101卷 751-759页

作者： Guangmin yang Jianyan lin Guanwu li Tian li Dong wang Weitao Zheng College of Physics Changchun Normal University School of Materials Science and Engineering Northwestern Polytechnical University Key Laboratory of Automobile Materials of MOE School of Materials Science and Engineering and Jilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy Materials Jilin University

Oxygen vacancies（Ov） within metal oxide electrodes can enhance mass/charge transfer dynamics in energy storage ***,construction of surface Ovoften leads to instability in electrode structure and irreversible electrochemical reactions,posing a significant *** overcome these challenges,atomic heterostructures are employed to address the structural instability and enhance the mass/charge transfer dynamics associated with phase conversion mechanism in aqueous electrodes,Herein,we introduce an atomic S-Bi2O3heterostructure(sulfur（S） anchoring on the surface Ovof Bi2O3).The integration of S within Bi2O3lattice matrix triggers a charge imbala nce at the heterointerfaces,ultimately resulting in the creation of a built-in electric field（BEF）.Thus,the BEF attracts OH-ions to be adsorbed onto Bi within the regions of high electron cloud overlap in S-Bi2O3,facilitating highly efficient charge ***,the anchored S plays a pivotal role in preserving structural integrity,thus effectively stabilizing the phase conversion reaction of *** a result,the S-Bi2O3electrode achieves72.3 mA h g-1at 10 A g-1as well as high-capacity retention of 81.9% after 1600 *** innovative SBi2O3design presents a groundbreaking approach for fabricating electrodes that exhibit efficient and stable mass and charge transfer ***,it enhances our understanding of the underlying reaction mechanism within energy storage electrodes.

关键词： Anchoring effect Atomic heterostructure Charge/mass transfer Oxygen vavancy Structural integrity