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Science china chemistry 2005年第5期48卷 424-430页

作者： LI Di1, SUN Chunyan1, HUANG Yunjie1, LI Jinghong1,2 & CHEN Shaowei3.1. State Key Laboratory of Electroanalytical chemistry, Changchun Institute of Applied chemistry, Chinese Academy of Sciences, Changchun 13.022, china 2. {3. of chemistry, Tsinghua university, Beijing 100084, china 3. department of chemistry, university of California, Santa Cruz, Santa Cruz, CA 95064, USA 1. State Key Laboratory of Electroanalytical chemistry Changchun Institute of Applied chemistry Chinese Academy of Sciences 130022 Changchun China 2. department of chemistry Tsinghua University 100084 Beijing China 3. department of chemistry University of California 95064 Santa Cruz Santa Cruz CA USA

Electron transfer through the self-assembled monolayers (SAMs) on gold nanopar-ticles is investigated by using the monolayer protected gold nanoclusters (MPCs) as elec-tron-transfer mediators. 3.Mercaptopropionic acid (MPA) and 11-meraptoundecanoic acid (MUA) MPCs were employed to catalyze the redox reaction between potassium ferricyanide and sodium thiosulfate. The catalytic mechanism was proposed that the MPCs act as diffusing elec-tron-mediators and electron transfers to and from the MPCs surface. Therefore the electron transfer rate through the capping layers would be proportional to the MPCs catalyzed reaction rate, which was monitored by the UV absorbance of ferricyanide. The calculated apparent rate constant was orders of magnitude smaller than that of the maximum of tunneling current, which was attributed to the splited energy level of the nanoscale particles.

关键词： electron transfer, three-dimensional self-assembled monolayers, redox reaction, electron transfer mediator, surface effect.

Congruences on ideal nil-extension of completely regular semigroups

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Chinese Science Bulletin 1998年第5期43卷 379-381页

作者： REN Xueming 1, 2 GUO Yuqi 2 and CEN Jiaping (Shum Kar-ping) 3.. department of Mathematics, Xi’an university of Architecture & Technology, Xi’an 710055, china 2. department of Mathematics, Yunnan university, Kunming 650091, china 3. department of department of Mathematics Xi’an University of Architecture & Technology Xi’an China department of Mathematics Yunnan University Kunming China department of Mathematics Chinese University of Hong Kong Hong Kong

Let S be an ideal nil-extension of a completely regular semigroup K by a nil semigroup Q with zero. A concept of admissible congruence pairs (δ,ω) of S is introduced, where δ and ω are a congruence on Q and a congruence on K respectively. It is proved that every congruence on S can be uniquely respresented by an admissible congruence pair (δ,ω) of S. Suppose that ρ K denotes the Rees congruence induced by the ideal K of S. Then it is shown that for any congruence σ on S,a mapping Γ:σ|→(σ Q,σ K) is an order-preserving bijection from the set of all congruences on S onto the set of all admissible congruence pairs of S,where σ K is the restriction of σ to K and σ Q=(σ∨ρ K)/ρ K. Moreover,the lattice of congruences of S is also discussed. As a special case,every congruence on completely Archimedean semigroups S is described by an admissible quarterple of S. The following question is asked: Is the lattice of congruences of the completely Archimedean semigroup a semimodular lattice?

关键词： completely regular semigroups ideal nil-extension congruences.

Experimental remolding on the caprock's 3. strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area

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Science china Earth Sciences 2005年第7期48卷 863-874页

作者： DENG Jun1,HUANG Dinghua2,WANG Qingfei1,WAN Li1,SUN Zhongshi3.YANG Liqiang1 & GAO Bangfei1 1. State Key Laboratory of Geological Processes and Mineral Resources,china university of Geosciences,Beijing 100083.china 2. Faculty of Earth Sciences,china university of Geosciences,Wuhan 43.074,china 3. department of Earth Sciences,jilin university,Changchun 13.061,china State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China department of Earth Sciences Jilin University Changchun 130061 China

Based on field observations and rheology analysis, we perform one analogue experiment and remold the 3. structural frame of Tongling deposit concentrating area firstly. Then we disassemble and dialyze the 3. structures of the model using the methods of "slicing" and "stripping". A series of sliced planes vertical to the fold hinges show similar landscapes of that in the drill hole profiles. Meanwhile, layer stripping analysis indicates that the deformation features of each layer in the model are qualitatively analogical to those obtained from field observations. Through contrasting the 3. structure between the experimental model and the field phenomena, we verify the following 3. deformation features of the caprock in this area: (1) the Tongling area mainly consists of three series of NE S-typed fold groups; (2) in the uniform stress field, the incoherent folds universally develop in different positions, along different axes as well as in different strata; (3. the faults propagate upward which are mostly inter-bedded detachment faults, while the fold amplitudes decrease while going deeper; and (4) the folds and cleavages are highly developed in the Silurian System indicating that the deformation effect of the Indosin-ian-Yanshanian structural layer terminates at this layer, which suggests that the Silurian System is the crucial layer for the inversion between brittle and plastic deformation domains and the underlying strata are subject to the control of another deformation system with distinct properties.

关键词： Tongling deposit concentrating area Indosinian-Yanshanian epoch 3. structural frame of the caprock analogue experiment slicing and stripping analysis structural model.

Decoding the inconsistency of six cropland maps in china

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The Crop Journal 2024年第1期12卷 281-294页

作者： Yifeng Cui Ronggao Liu Zhichao Li Chao Zhang Xiao-Peng Song jilin Yang Le Yu Mengxi Chen Jinwei Dong Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China university of Chinese Academy of Sciences Beijing 100049China department of Geographical Sciences University of MarylandCollege ParkMD 20740USA College of Grassland Science and Technology China Agricultural UniversityBeijing 100193China Ministry of Education Ecological Field Station for East Asian Migratory Birds Department of Earth System ScienceInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China Ministry of Education Ecological Field Station for East Asian Migratory Birds Beijing 100084China Tsinghua university(department of Earth System Science)-Xi’an Institute of Surveying and Mapping Joint Research Center for Next-Generation Smart Mapping Beijing 100084China Institute of Remote Sensing and Geographic Information System Peking UniversityBeijing 100871China department of Forest and Conservation Sciences University of British ColumbiaVancouverBCV6T 1Z4Canada

Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like *** widely used medium-to-high-resolution satellite-based cropland maps have been developed from various remotely sensed data sources over the past few decades,considerable discrepancies exist among these products both in total area and in spatial distribution of croplands,impeding further applications of these *** factors influencing their inconsistency are also *** this study,we evaluated the consistency and accuracy of six cropland maps widely used in china in circa 2020,including three state-of-the-art 10-m products(i.e.,Google Dynamic World,ESRI Land Cover,and ESA WorldCover)and three 3.-m ones(i.e.,GLC_FCS3.,GlobeLand 3.,and CLCD).We also investigated the effects of landscape fragmentation,climate,and agricultural *** using a ground-truth sample revealed that the 10-m-resolution WorldCover provided the highest accuracy(92.3.).These maps collectively overestimated Chinese cropland area by up to 56%.Up to 3.%of the land showed spatial inconsistency among the maps,concentrated mainly in mountainous regions and attributed to the varying accuracy of cropland maps,cropland fragmentation and management practices such as *** work shed light on the promotion of future cropland mapping efforts,especially in highly inconsistent regions.

关键词： Consistency and accuracy 10-and 3. m Cropland mapping Agricultural management china

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2 & ZHAO Xiqiang3.1. Mechanics department, Shandong university of Technology, Zibo 255049, china 2. Civil Engineering department, Dalian university of Technology, Dalian 116024, china 3. Mathematics department, Ocean university of china, Qingdao 266071, china Mechanics department Shandong University of Technology Zibo 255049 China Civil Engineering department Dalian University of Technology Dalian 116024 China Mathematics department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

NUMERICAL COMPUTATION OF BOUNDED SOLUTIONS FORA SEMILINEAR ELLIPTIC EQUATION ON AN INFINITE STRIP

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Journal of Computational Mathematics 1999年第2期17卷 159-170页

作者： Fu-ming Ma(department of Mathematics, jilin ’university, Changchun 13.023.{3.) 吉林大学数学系吉林长春

In this paper, we consider the computation of bounded solutions of a semilinear elliptic equation on an infinite strip. The dynamical system approach and reduction on center manifold are used to overcome the difficult... 详细信息

关键词： numerical method nonlinear PDE center manifold

Progress in the study of molecular organized assemblies by dielectric relaxation spectroscopy

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Progress in Natural Science:Materials International 2006年第3期16卷 221-230页

作者： ZHAO Kongshuang, HE Kejuan and WEI Suxiang (department of chemistry, Beijing Normal university, Beijing 100875,{3. department of chemistry, South{3. Normal university, Guangzhou 51063.,{3.) [a]department of chemistry Beijing Normal University Beijing China [b]department of chemistry South China Normal University Guangzhou China

Because dielectric spectroscopy covers a great many problems in physical and chemical systems occurring in an extremely wide frequency range, the study of this method plays an important role in physical chemistry. As an effective tool to detect inner properties of substance systems, the dielectric spectroscopy method is widely used in chemical systems and has been dramatically developed in recent decade. This review paper describes the applications of the dielectric spectroscopy in the chemical field, and main concentrations are focused on the micelle, microemulsion and other so-called molecular organized assemblies. Some dielectric principles and models proposed for these systems are introduced. In addition, recent technical developments in dielectric spectroscopy and developing trend of this method in other chemical systems are reviewed.

关键词： dielectric relaxation micelle microemulsion vesicle relaxation time.

Direct CP violation in hadronic B decays

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Science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2 & Lü Caidian3.1. department of Physics, Lishui university, Lishui 3.3.00,china 2. department of Physics, Shanghai Jiaotong university, Shanghai 20003., china 3. Institute of High Energy Physics, Beijing 100049,china department of Physics Lishui University Lishui 323000 China department of Physics Shanghai Jiaotong University Shanghai 200030 China Institute of High Energy Physics Beijing 100049 China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

Local and non-local sources of airborne particulate pollution at Beijing——The ratio of Mg/Al as an element tracer for estimating the contributions of mineral aerosols from outside Beijing

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Science china chemistry 2005年第3期48卷 253-264页

作者： HAN Lihui1, ZHUANG Guoshun1,2,3. SUN Yele1 & WANG Zifa3.1. The Center for Atmospheric Environmental Study, department of chemistry, Beijing Normal university, Beijing 100875,{3. 2. Center for Atmospheric chemistry Study, department of Environmental Science & Engineering, Fudan university, Shanghai 20043.,{3. 3. LAPC/NZC, Institute of Atmospheric Physics, CAS, Beijing 100029,{3. 1. The Center for Atmospheric Environmental Study Department of Chemistry Beijing Normal University 100875 Beijing China 2. Center for Atmospheric chemistry Study Department of Environmental Science & Engineering Fudan University 200433 Shanghai China 3. Institute of Atmospheric Physics CAS LAPC/NZC 100029 Beijing China

A new element tracer technique has firstly been established to estimate the contri-butions of mineral aerosols from both inside and outside Beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside Beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in Beijing, of which mineral aerosol accounted for 3.%―67% of total suspended particles （TSP）, 10%―70% of fine particles （PM2.5）, and as high as 74% and 90% of TSP and PM2.5, respectively, in dust storm. The sources from outside Beijing contributed 62% （3.%―86%） of the total mineral aerosols in TSP, 69% （52%―90%） in PM10, and 76% （59%―93.） in PM2.5 in spring, and 69% （52%―83.）, 79% （52%―93.）, and 45% （7%―79%） in TSP, PM10, and PM2.5, respectively, in winter, while only20% in summer and autumn. The sources from outside Beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in Beijing. The contributions from outside Bei-jing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.

关键词： mineral aerosol local sources non-local sources dust storm re-suspended dust element tracer technique.

Synthesis and Efficiency of a SphericalMacroporous Epoxy-dicyandiamide ChelateResin for Preconcentrating and SeparatingTrace Au, Hg, Pd and Ru from Samples

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Chemical Research in Chinese Universities 2001年第2期17卷 168-174页

作者： GONG Bo-lin, LI Xue-qiang and WANG Feng-rong (department of chemistry, Ningxia university, Yinchuan 750021,{3.) CHANG Xi-jun (department of chemistry, Lanzhou university, Lanzhou 73.000,{3.) Ningxia Univ Dept Chem Yinchuan 750021 Peoples R China Lanzhou Univ Dept Chem Lanzhou 730000 Peoples R China

A novel spherical macroporous epoxy-dicyandiamide chelate resin was synthesized simply and rapidly from epoxy resin and used for the preconcentration and separation of trace amounts of Au (Ⅲ ), Hg (Ⅱ ), Pd (Ⅳ) and Ru (Ⅲ) ions from solution samples. The analyzed ions can be quantitatively concentrated by the resin at a flow rate of 2. 0 mL/min at pH 4, and can also be desorbed with 15 mL of 4 mol/L HCl + 0. 3.g thiourea from the resin column with recoveries of 96. 5%-99. 0%. After the chelate resin was reused for 7 times, the recoveries of these ions were still over 92%, and 400-1 000 times of excess of Fe(Ⅲ ), Al(Ⅲ ), Ni( II), Mn( Ⅱ ), Cr (Ⅲ ), Cu ( Ⅱ ), Cd (Ⅱ ) and Pb (Ⅱ ) caused little interference with the determination of these ions by an inductively coupled plasma optical emission spectrometer (ICP-OES ). The capacities of the resin for the analytes are in the range of 0. 3.~0. 92 mmol/g. The RSDs of the proposed method are in the range of 1. 1 % ~4. 0% for each kind of the analyzed ions. The recoveries of a standard added in real solution samples are between 96. 5% and 98. 5%, and the results for the analyzed ions in a powder sample are in good agreement with their reported values.

关键词： Concentration Separation Macroporous epoxy-dicyandiamide chelate resin Gold Mercury Palladium and ruthenium.