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The roles of heterogeneous chemical processes in the formation of an air pollution complex and gray haze

Science china Chemistry 2011年第1期54卷 145-153页

作者： ZHU Tong,SHANG Jing & ZHAO DeFeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and Engineering,Peking university,{2. 100871,china 1. State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and Engineering Peking University Beijing 100871 China

Urban and regional air pollutions are characterized by high concentrations of secondary pollutants such as photo-oxidants （mainly ozone） and fine particulate matter, which are formed through chemical reactions of the primary pollutants emitted from various sources. The accumulation of these pollutants under stagnant meteorological conditions results in the formation of gray haze, reducing visibility and causing major impacts on human health and climate. In an air pollution complex, the co- existence of high concentrations of primary and secondary gaseous and particulate pollutants provides a large amount of reac- tants for heterogeneous reactions on the surface of fine particles; these reactions change the oxidizing capacity of the atmos- phere, as well as chemical compositions along with the physicochemical and optical properties of particulate matter, thereby accelerating formation of the air pollution complex and gray haze. Using in situ technologies, such as diffuse reflectance infra- red Fourier-transform spectroscopy and single-particle Raman spectroscopy, we systematically investigated the reaction kinet- ics and mechanisms of gaseous pollutants （i.e., NO2. SO2. 03, and formaldehyde） on the surfaces of the major components of atmospheric particles such as CaCO3, kaolinite, montmorillonite, NaC1, sea salt, A12.3, and Tit2. We found that the main re- action products were sulfate, nitrate, or formate, which can change the hygroscopicity and light extinction parameters of those particles significantly. By analyzing the reaction kinetics of these heterogeneous reactions, we identified synergetic mechanisms of the three ternary reaction systems, ,i.e., NOE-particles-H2., SO2.particles-O3, and organics/SO2.particles-UV illumination. These synergetic mechanisms can provide experimental and theoretical bases for understanding the feedback mechanisms and nonlinear processes in the formation of an air pollution complex and gray haze.

关键词： fine particles secondary pollutants oxidizing capacity ternary reaction nonlinear processes

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A DIFFERENTIAL GEOMETRIC DESCRIPTION FOR TIME-INDEPENDENT CHETAEV'S NONHOLONOMIC MECHANICAL SYSTEM WITH UNILATERAL CONSTRAINTS

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Acta Mechanica Solida Sinica 2002年第1期15卷 62-67页

作者： Zhang Yi (Department of Urban Constrution,university of Science & Technology of Suzhou,Suzhou 2.5011,china)Mei Fengxiang (Department of Applied Mechanics,{2. Institute of Technology,{2. 100081,china) Department of Urban Construction University of Science and Technology of Suzhou Suzhou 215011 China Department of Applied Mechanics Beijing Institute of Technology Beijing 100081 China

By applying the framework of the tangent bundle geometry to the method of Lagrange multi- pliers,a geometric description of Chetaev's nonholonomic systems subjected to unilateral nonholonomic con- straints trod unilat... 详细信息

关键词： analytical mechanics unilateral constraint differential geometry nonholonomic constraint tangent bundle geometry

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Rural Credit Innovation:Experience of china

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清华大学学报（哲学社会科学版） 2009年第S1期24卷 89-96页

作者： HAO Xiu-qing(School of Economics and Management,Tsinghua university,beijing 100084.{2.)

This paper is based on literature and interviews with the management of a leading agricultural firm which has developed a new credit rural *** uses the case study to generalize a new model of rural credit *** provides the government with an example on how to help solve rural credit problems and poverty *** also provides the banking industry with a new profit-making model,which benefits farmers at the same time as well.

关键词： Rural Credit Innovation Practice Agricultural Industrialization chinaAbout the Author: HAO Xiu-qing,School of Eonomics and Management,Tsinghua university,Ph.D.Candidate,research direction: technology innovation

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后生遗传修饰及其对动物克隆的影响

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生物工程学报 2003年第1期19卷 9-12页

作者：李文雍郁卫东陈清轩中国科学院遗传与发育生物学研究所

近年来 ,不断有新的哺乳动物和两栖类动物被成功克隆 ,但这并不能掩盖克隆效率过低和克隆动物异常的现实 ,为了解决这一问题 ,人们对克隆机理进行了大量研究。高度分化的体细胞核在去核的卵质中去分化和再程序化不完全是导致动物克隆失... 详细信息

近年来 ,不断有新的哺乳动物和两栖类动物被成功克隆 ,但这并不能掩盖克隆效率过低和克隆动物异常的现实 ,为了解决这一问题 ,人们对克隆机理进行了大量研究。高度分化的体细胞核在去核的卵质中去分化和再程序化不完全是导致动物克隆失败的主要原因 ,而去分化和再程序化不完全主要是由于基因组去甲基化不充分和过早再甲基化引起克隆胚中甲基化水平比正常胚中偏高所至 ,这可引起一些重要基因的异常表达 ,尤其是印记基因。这些机制的研究对提高克隆效率有着重要意义。

关键词：后生遗传修复动物克隆再程序化甲基化基因组印记

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Protection of Mice with a Divalent Tuberculosis DNA Vaccine Encoding Antigens Ag85B and MPT64

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Acta Biochimica et Biophysica Sinica 2004年第4期36卷 269-276页

作者： Xia TIAN, Hong CAI, and Yu-Xian ZHU* The National Laboratory of Protein Engineering and Plant Genetic Engineering, Peking university, beijing 100871,{2. The National Laboratory of Protein Engineering and Plant Genetic Engineering Peking UniversityBeijing 100871 China

DNA vaccine may be a promising tool for controlling tuberculosis development. However, vaccines encoding single antigens of mycobacterium did not produce protective effect as BCG did. In the present study, we evaluated the immunogenicity and protective efficacy of a divalent DNA vaccine encoding two immunodominant antigens Ag85B and MPT64.of Mycobacterium tuberculosis. We found that both humoral and Th1-type (high IFN-γ, low IL-4. cellular responses obtained from the divalent DNA vaccine group were significantly higher than that conferred by BCG. RT-PCR results showed that antigens were expressed differentially in various organs in divalent DNA vaccine group. The survival rate for mice treated with the divalent DNA vaccine after challenging with high doses of virulent M. tuberculosis H37Rv was significantly higher than that of the BCG group or any of the single DNA vaccine group. Significant differ- ences were also found between the single and divalent DNA vaccinated mice in terms of body, spleen and lung weight. Bacterial loading decreased about 2.00-fold in lungs and about 100-fold in spleens of divalent DNA vaccinated mice when compared with that of the control group. We conclude that our divalent DNA vaccine may be a better choice for controlling tuberculosis disease in animals.

关键词： tuberculosis divalent DNA vaccine immunogenicity protection

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Comparison of Soil Biota Between Organic and Conventional Agroecosystems in Oregon, USA

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Pedosphere 2005年第3期15卷 395-403页

作者： WUShan-Mei HUDun-Xiao E.R.INGHAM universityofCalifornia BerkeleyCA94720（USA） chinaAgriculturaluniversity Beijing100094（China） OregonStateuniversity CorvallisOR（USA）

Soil samples at 0-10 cm in depth were collected periodically at paired fields in Corvallis, Oregon, USA to compare differences in soil microbial and faunal populations between organic and conventional agroecosystems. Results showed that the organic soil ecosystem had a significantly higher (P < 0.05) average number or biomass of soil bacteria; densities of flagellates, amoebae of protozoa; some nematodes, such as microbivorous and predaceous nematodes and plant-parasitic nematodes; as well as Collembola. Greater numbers of Rhabditida (such as Rhabditis spp.), were present in the organic soil ecosystem while Panagrolaimus spp. were predominant in the conventional soil ecosystem. The omnivores and predators of Acarina in the Mesostigmata (such as Digamasellidae and Laelapid), and Prostigmata (such as Alicorhaiidae and Rhagidiidae), were also more abundant in the organic soil ecosystem. However, fungivorous Prostigmata (such as Terpnacaridae and Nanorchestidae) and Astigmata (such as Acarida) were significantly higher (P < 0.05) in the conventional soil ecosystem, which supported the finding that total fungal biomass was greater in the conventional soil ecosystem. Seansonal variations of the population depended mostly on soil moisture condition and food web relationship. The population declined from May to October for both agroecosystems. However, higher diversities and densities of soil biota survived occurred in the organic soil ecosystem in the dry season.

关键词： microarthropods nematodes organic and conventional agroecosystems soil microbial population

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New formulae for calculating activities from binary system phase diagrams containing solid solution by introducing the parameterθ

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International Journal of Minerals,Metallurgy and Materials 1997年第3期11卷 1-4页

作者： ZHANG Fan XIE Fanyou CAI Wenjuan CHOU Kuochih (Applied Science School, university of Science and Technology beijing, beijing 100083, china)

New formulae for calculating activities and activity coefficients from binary phase diagrams containing solidsolution are presented. In the new formulae, a parameterθ is introduced. It seems be more efficient The app... 详细信息

关键词： phase diagram activity activity coefficient solution θ parameter

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Network expansion by adding arcs and/or nodes

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Progress in Natural Science:Materials International 2005年第3期 8-12页

作者： YANG Xiaoguang 1ˇˇ and ZHANG Jianzhong 2. (1.academy of Mathematics and Systems Science,Chinese academy of {2.,{4.100080,china 2.City university of Hong Kong,Kowloon,Hong Kong,china) academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China City university of Hong Kong Kowloon Hong Kong China

In this paper,we consider a new network improvement model,which is to expand a network by adding new arcs and/or new nodes to satisfy the excess *** the new arcs and new nodes,there are constructing costs for building these new *** purpose of our model is to minimize the total constructing *** is found that even if the constructing costs for all new nodes are zero or all new arcs are zero,solving the problem within an approximation ratio O(ln(|V 1 |+|V 2.|))remains NP-hard,where V 1 is the orig-inal node set,and V 2.is the candidate node *** also present an MIP formulation for the problem and propose some heuristic ideas to solve the problem.

关键词： network expansion arc/node inapproximability MIP formulation.

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Study of the Deception Effect of Radar Equipped with Decoys

Study of the Deception Effect of Radar Equipped with Decoys

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Asia Simulation conference 2.08/the 7th International Conference on System Simulation and Scientific Computing（ICSC‘2.08）

作者： ZHOU Wei-guang the Institute of Electronics,Chinese academy of sciences,{2.,china LUO Ji-run the Institute of Electronics,Chinese academy of sciences,{2.,china JIA Yu-gui the Second graduate School of Air Force,{2.,china. WANG Hua-bin the Second graduate School of Air Force,{2.,china.

Considering the mechanism of two-channel direction-finding systems with four-arm spiral antenna, guidance signal generation model related to the superposed field radiated by the antenna of radar and decoy is presented. A simplified and practical movement model of Anti-Radiation Missile is introduced. The dynamic simulation algorithms and formulae for analyzing deception effect are proposed. Numerical results show that a high survival probabilities of radar and decoy can be achieved if the decoy level is set to some appropriate values when the distance between radar and decoy is set to 2.0-300 meters, and the initial phase of the decoy radiation field has relatively less effect on the survival probability.

关键词： Study of the Deception Effect of Radar Equipped with Decoys

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A FRAMEWORK OF FUZZY LANDSCAOE THEORY WITH AN APPLICATION TO ALLIANCE ANALYSIS

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Journal of Systems Science & Complexity 2003年第1期16卷 1-12页

作者： S. Suganuma V. N. Huynh Y. Nakamori S. Y.Wang academy of Mathematics and Systems sciences Chinese academy of sciences {4. 100080 china) K. K. Lai Japan Advanced Institute of Science and Technology Department of Computer Science University of Quinhon 170 - An Duong VuongJapan Advanced Institute of Science and Technology 1-1 Asahidai TatsunokuchiDepartment of Management Sciences City University of Hong Kong 1 - 1 Asahidai Tatsunokuchi Ishikawa 923-1292 Japan academy of Mathematics and Systems sciences Chinese Academy of SciencesBeijing 100080 ChinaQuinhon VietnamIshikawa 923-1292JapanKowloon Hong Kong

In this paper, we provide a framework of fuzzy landscape theory and discuss an application to alliance analysis. The fuzzy landscape theory may allow us to analyses a variety of aggregation processes in political, economic, and social problems in a more flexible manner. The simulation results for the problems of the international alignment of the Second World War in Europe and the coalition formation in standard-setting alliances in the case of the UNIX operating system are compared with those given by the original theory.

关键词： Fuzzy landscape theory alliance partition genetic algorithm.

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