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Remote sensing based shrub above-ground biomass and carbon storage mapping in Mu Us desert,china

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Science china(Technological {1.) 2010年第S1期53卷 176-183页

作者： XU Min 1.2,CAO ChunXiang 1.TONG QingXi 1.li ZengYuan 3,ZHANG Hao 1.HE QiSheng 1.2,GAO MengXu 1.2,{1. Jian 1.2,ZHENG Sheng 1.2,CHEN Wei 1.2.& ZHENG LanFen 1.1.tate Key Laboratory of Remote Sensing Science,Jointly Sponsored by the institute of Remote Sensing Applications of chinese Academy of sciences and beijing Normal University,beijing 1.01.1.china 2 Graduate School of the chinese Academy of sciences,beijing 1.0049,china 3 Research institute of Forest Resources and Information Techniques,chinese Academy of Forestry,beijing 1.009,china 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China 2. Graduate School of the chinese Academy of {1. Beijing 100049 China 3. Research institute of Forest Resources and Information Techniques Chinese Academy of Forestry Beijing 10009 China

The estimation of above-ground biomass(AGB) and carbon storage is very important for arid and semi-arid ***-1./B satellite data combined with field measurement data was used for the estimation of shrub AGB and carbon storage in the Mu Us desert,*** correlations of shrub AGB and spectral reflectance of four bands as well as their combined vegetation indexes were respectively analyzed and stepwise regression analysis was employed to establish AGB prediction *** prediction equation based on ratio vegetation index(RVI)was proved to be more suitable for shrub AGB estimation in the Mu Us desert than *** AGB and carbon storage were mapped using the RVI based prediction model in *** statistics showed the western Mu Us desert has relatively high AGB and carbon storage,and that the gross shrub carton storage in Mu Us desert reaches 1. 799 2.0 t,which has greatly contributed to the carbon fixation in northern china.

关键词： above-ground biomass carbon storage Mu Us desert HJ-1./B remote sensing

Size-dependent hydroxyl radicals generation induced by SiO_2.ultra-fine particles: The role of surface iron

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Science china Chemistry 2009年第7期52卷 1033-1041页

作者： SHANG Yu1, ZHU Tong1, li Yi1,2.& {2. JinCai3 1 College of Environmental sciences and Engineering, Peking University, beijing 100871, china 2.chinese Academy of Meteorological sciences, beijing 100871, china 3 institute of Chemistry, chinese Academy of sciences, beijing 100871, china 1. College of Environmental sciences and Engineering Peking University Beijing 100871 China 2. chinese Academy of Meteorological {1. Beijing 100871 China 3. institute of Chemistry Chinese Academy of Sciences Beijing 100871 China

Oxidative stress and hydroxyl radicals (·OH) play important roles in adverse health effects caused by inhalable ambient air particles (PM1.). The ultra-fine fraction of PM1. has been hypothesized as one of the critical contributors to ·OH generation. Both in vivo and in vitro studies have shown that ultra-fine particles (UFPs) or nano-particles generate more ·OH than larger particles with identical mass and composition. Both the surface area and surface-adsorbed redox-active metals have been suggested as factors to determine the oxidative capacity of UFPs. In this study, the ·OH-generating capabi{2.ty of dif-ferent sizes of SiO2.particles was investigated in order to determine which factor influences particle-induced ·OH generation. The amount of ·OH generated in both acellular and cellular systems was quantified using a capillary electrophoresis method following exposure to SiO2.particles with diameters of 1., 1.0, and 500 nm. The amount of ·OH was strongly dependent on particle size, and a significant enhancement was observed only with 1. nm particles. Further studies indicated a close association between ·OH and iron ion concentration (R2.= 0.81., p1.. Washed particles, with their surface iron being removed, did not generate ·OH. The iron-containing leachate from these washings was able to enhance ·OH production as untreated particles did. Therefore, the presence of adsorbed iron on the surface of the SiO2.particles is presented as a possible mechanism of UPFs-induced ·OH generation. The SiO2.acted as an inert substrate, and the surface of ultra-fine SiO2.particles acted as a carrier for iron.

关键词： ultra-fine particles nano-particles ·OH oxidative stress size-effect

Characteristics of InGaN multiple quantum well blue-violet laser diodes

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Science china(Technological {1.) 2006年第6期49卷 727-732页

作者： li Deyao1. ZHANG Shuming1. WANG Jianfeng1. CHEN Jun1. CHEN lianghui2, CHONG Ming2, ZHU Jianjun1. zhao Degang1. liU Zongshun1. YANG Hui1.& liANG Junwu1.1. State Key Laboratory of Integrated Optoelectronics, institute of Semiconductors, chinese Academy of sciences, beijing 1.0083, china 2. Nano-Optoelectronics Laboratory, institute of Semiconductors, chinese Academy of sciences, beijing 1.0083, china State Key Laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Nano-Optoelectronics Laboratory Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Studies on InGaN multiple quantum well blue-violet laser diodes have been reported. Laser structures with long-period multiple quantum wells were grown by metal-organic chemical vapor deposition. Triple-axis X-ray diffraction (TAXRD) measurements show that the multiple quantum wells were high quality. Ridge waveguide laser diodes were fabricated with cleaved facet mirrors. The laser diodes lase at room temperature under a pulsed current. A threshold current density of 3.3 kA/cm[2.; a characteristic temperature T 0 of 1.5 K were observed for the laser diode.

关键词： metalorganic chemical vapor deposition (MOCVD), GaN-based laser diodes, multiple quantum well, ridge waveguide, threshold current.

Petrogenesis and dating of the Kangding complex,Sichuan Province

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Science china Earth {1. 2005年第5期48卷 622-634页

作者： CHEN Yuelong 1 , LUO zhaohua 1 , zhao Junxiang, {2. Zhihong, ZHANG Hongfei & SONG Biao 3 1. Faculty of Earth sciences and Natural Resources, china University of Geosciences, beijing 100083, china 2. Faculty of Earth sciences, china University of Geosciences, Wuhan 430074, china 3. beijing SHRIMP Center, institute of Geology, chinese Academy of Geological sciences, beijing 100037, china 1. Faculty of Earth sciences and Natural Resources China University of Geosciences 100083 Beijing China 2. Faculty of Earth sciences China University of Geosciences 430074 Wuhan China 3. beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

An analysis of major and trace element geochemistry and SHRIMP U-Pb zircon dating of mafic, intermediate, and felsic rocks from the Mianning metamorphic complex of Si- chuan Province was conducted. One of our conclusions is that a majority of the zircons crystal- lized between 72.1}and 773 Ma in a magmatic regime. The complexes contain early to late Pa- leo-proterozoic relict zircons from ancient continental crust. The oldest age, 2.68 Ma, may rep- resent the basement of the Yangtze block. Overgrowth zircon rims and palingenetic zircons have been observed and dated, and are believed to have formed after crystallization, during Paleozoic and Mesozoic metamorphic-anatexis. We also conclude that depletion of Nb, Ta, HREE, in a spider-diagram normalized to primitive mantle and calc-alkaline association, implies that they formed in island-arc or under-plating settings.

关键词： Kangding complex, zircons, SHRIMP, tectonic setting.

Development of solar-blind AlGaN 1.8x1.8 Ultraviolet Focal Plane Arrays

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Science china(Technological {1.) 2008年第6期51卷 820-826页

作者： YUAN YongGang1, ZHANG Yan1, CHU KaiHui1, li XiangYang1, zhao DeGang{2. YANG Hui2.1 State Key Laboratories of Transducer Technology, Shanghai institute of Technical Physics, chinese Academy of sciences, Shanghai 2.0083, china 2.institute of Semiconductors, chinese Academy of sciences, beijing 100083, china State Key Laboratories of Transducer Technology Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

This paper reports the development of solar-blind aluminum gallium nitride (AlGaN) {2.8×{2.8 UV Focal Plane Arrays (FPAs). The back-illuminated hybrid FPA archi- tecture consists of an {2.8x{2.8 back-illuminated AlGaN PIN detector array that is bump-mounted to a matching {2.8x{2.8 silicon CMOS readout integrated circuit (ROIC) chip. The {2.8×{2.8 p-i-n photodiode arrays with cuton and cutoff wave-lengths of 2.3 and 2.8 nm, with a sharp reduction in response to UVB (2.0―32. nm) light. Several examples of solar-blind images are provided. This solar-blind band FPA has much better application prospect.

关键词： AlGaN photodiode ultraviolet FPA solar-blind

Adsorption behavior of hexadecyltrimethylammonium bromide (CTAB) to mica substrates as observed by atomic force microscopy

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Science china Chemistry 2005年第2期48卷 101-106页

作者： zhao Feng1.2. DU Yukou1. YANG Ping1. {1. Xingchang2.& TANG Ji’an2.1. Chemistry and Chemical Engineering Department, Suzhou University, Suzhou 2.1}006, china 2. Key Laboratory of Colloid and Interface Science, institute of Chemistry, chinese Academy of sciences, {12., china Correspondence should be addressed to Tang Ji’an (email: jatang@***) 1. Chemistry and Chemical Engineering Department Suzhou University 215006 Suzhou China 2. Key Laboratory of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China

Atomic force microscopy is employed to study the adsorption behavior of CTAB to mica surfaces. Results show that conformational transitions from globular micelles→cylindrical micelles→flat films are observed in the process of the adsorption of CTAB to mica at twice the bulk critical concentration. However, in 0.5 cmc CTAB solution, the adsorbed CTAB molecules to mica form the layered film structures, and apparent conformational transitions do not appear. Meanwhile, the phenomena of the adsorption of CTAB to mica and the dissociation of mica sur- faces are periodically observed.

关键词： atomic force microscopy (AFM), micelle, behavior of adsorption, the dissociation of mica surfaces.

Stochastic structural model of rock and soil aggregates by continuum-based discrete element method

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Science china(Technological {1.) 2005年第z1期48卷 95-106页

作者： WANG Yuannian1. zhao Manhong1. {1. Shihai1.& J.G. Wang2.0} institute of Mechanics, chinese Academy of sciences, beijing 100080, china 2. Tropical Marine Science institute, National University of Singapore, 1. Kent Ridge Crescent, Singapore 1.92.0 1. institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. Tr?pical Marine Science institute National University of Singapore 10 Kent Ridge Crescent 119260 Singapore

This paper first presents a stochastic structural model to describe the random geometrical features of rock and soil aggregates. The stochastic structural model uses mixture ratio, rock size and rock shape to construct the microstructures of aggregates, and introduces two types of structural elements (block element and jointed element) and three types of material elements (rock element, soil element, and weaker jointed element) for this microstructure. Then, continuum-based discrete element method is used to study the deformation and failure mechanism of rock and soil aggregate through a series of loading tests. It is found that the stress-strain curve of rock and soil aggregates is nonlinear, and the failure is usually initialized from weaker jointed elements. Finally, some factors such as mixture ratio, rock size and rock shape are studied in detail. The numerical results are in good agreement with in situ test. Therefore, current model is effective for simulating the mechanical behaviors of rock and soil aggregates.

关键词： CDEM, rock and soil aggregate, mixture ratio.

The properties of halo structure for ^(1.)B

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Science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 781-787页

作者： HU ZhengGuo1. WANG Meng1. XU HuShan1. SUN ZhiYu1. WANG JianSong1. XIAO GuoQing1. ZHAN WenLong1. XIAO ZhiGang1. MAO RuiShi1.2, li Chen1. ZHANG XueYing1.2, ZHANG HongBin1. {1. TieCheng1. XU ZhiGuo1. WANG Yue1.2, CHEN RuoFu1.2, HUANG TianHeng1.2, FU Fen1.2, GAO Qi1.2, HAN JianLong1.2, ZHANG XueHeng1.2, ZHENG Chuan1.2, YU YuHong1.2.& GUO ZhongYan1.1.institute of Modern Physics, chinese Academy of sciences, Lanzhou 730000, china 2 Graduate University of the chinese Academy of sciences, beijing 1.0049, china 1. institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. Graduate University of the chinese Academy of {1. Beijing 100049 China

The total reaction cross section (1.2.±93 mb) of 1.B at the energy of 43.7 A MeV on C target has been measured by using the transmission method at the Radioactive Ion Beam {2.ne in Lanzhou (RIBLL). Assuming 1.B consists of a core 1.B plus two halo neutrons,the total cross section of 1.B on C target was calculated with the zero-range Glauber model,where double Gaussian density distributions and Gaussian plus HO density distributions were used. It can fit the experimental data very well. The characteristic of halo structure for 1.B was found with a large diffusion of the neutrons density distribution.

关键词： total cross section density distribution Glauber model the characteristic of halo structure

Experimental study of electron capture excitation in collisions between li-like N^(4+) ions and Na atoms

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chinese Science Bulletin 1997年第5期42卷 368-371页

作者： liU Zhanwen, ZHOU Sixin, ZHANG Wen, ZHANG Xuezhen GUOXiaohong, WANG Youde, MA Xinwen, YANGZhihu, liU Huiping, {2. Mengchun, YANG Feng, PAN Guangyan and li Dawan1. institute of Modern Physics, chinese Academy of sciences, Lanzhou 730000, china 2. institute of Physics, chinese Academy of sciences, beijing 100080, china institute of Modern Physics Chinese Academy of Sciences Lamhou China institute of Physia Chinese Academy of Sciences Beijing China

WITH the rapid development of the technique of ionized atoms, the charge states of atoms that can be obtained now are so high that the H-like U91. ions and naked U92. ions

关键词： single electron capture double electron capture emission cross section excited states.