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Simulation on C/A codes and analysis of GPS/pseudolite signals acquisition

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science china(Technological sciences) 2009年第5期52卷 1459-1462页

作者： ZHANG Lei shanghai institute of {2. physics,chinese academy of sciences,shanghai 200083,china shanghai institute of {2. physics Chinese Academy of Sciences Shanghai China

The global positioning system(GPS) is an extremely mature technique in the navigation and position-ing ***,there are still some limits in some aspects and for some special ***-cially,the performance of GPS needs to be improved with technological *** a GPS-like ground transmitter,the pseudolite provides a new research direction to achieve high positioning ac-curacy and *** this paper,we describe the core technologies of designing and simulation on the coarse acquisition codes in constructing the pseudolite *** the GPS/pseudolite integration system,the signal PRN 36 of the pseudolite and the GPS satellites signals are acquired in the modified receiver based on the computer software *** is shown that the pseudolite technology is ideally suited to augment the GPS alone and provide greater integrity,availability,and continuity of the navi-gation positioning system,especially for indoor use.

关键词： GPS pseudolite coarse acquisition(C/A) code acquisition

Preparation and Microstructure of Spinel Zinc Ferrite ZnFe_2._4 by Co-precipitation Method

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Journal of Wuhan University of Technology(Materials science) 2009年第6期24卷 927-930页

作者：任平 Department of Energy Sources and Environment Engineering Shanghai University of Electric Power

Spinel zinc ferrites ZnFe2.4, prepared by co-precipitation method using the zinc nitrate Zn（NO3）2.6H2. and ferric nitrate Fe（NO3）3·2.2. as the raw materials, were characterized by the thermo gravimetric analysis （TG） and differential scanning calorimeter （DSC）, X-ray diffraction （XRD） and scanning electron microscope （SEM）. The influence of synthesis conditions, such as Zn/Fe molar ratio, pH value, the sintering temperature and time, on the microstructures was detailedly investigated. The relationships between the microstructures and the synthesis conditions were discussed. The results show that the pure spinel zinc ferrites ZnFe2.4 are formed when the Zn/Fe molar ratio is 1.05∶2.at pH=8.5 or Zn/Fe molar ratio is 1∶2.at Ph=9-10, and the precursors are sintered at 1100 ℃ for 4 h. Especially no other phases are observed when the Zn/Fe molar ratio is 1∶2.at pH=10 and the precursor is sintered above 700 ℃ for 4 h. The higher sintering temperature and longer sintering time contribute to grain growth.

关键词： zinc ferrites ZnFe2.4 microstructures co-precipitation

Transverse patterns and spatiotemporal instability of a photorefractive oscillator

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chinese science Bulletin 1997年第9期42卷 724-729页

作者： ZHUANG Jun and TAN Weihan1. shanghai institute of Optics and Fine Mechanics,{2.s, shanghai 2.1800, china 2. shanghai University, shanghai 2.1800, china shanghai institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China shanghai University Shanghai China

IN time realm,instability and chaos phenomena of a nonlinear optical system have been dis-cussed *** recent years,as much interest was attracted to the transverse ef-fects in nonlinear optics,the study was developed t... 详细信息

关键词： photorefractive oscillator spatiotemporal instability transverse patterns.

Structural and microstructural transformations in Bi_2.r_2.a_(1-x)Y_xCu_2._(8+y) system

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chinese science Bulletin 1997年第3期42卷 192-196页

作者： SONG Chengyu, WEN Shulin and CHE Guangcan1. shanghai institute of Ceramics,{2.s, shanghai 2.0050, china 2. State Key Laboratory of Supercon-ductivity, institute of physics,{2.s, Beijing 100080, china shanghai institute of Ceramics Chinese Academy of Sciences Shanghai China State Key Laboratory of Superconductivity Institute of Physics Chinese Academy of Sciences Beijing China

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2.u3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity o... 详细信息

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2./sub>Cu3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity of the superconductive phase. In Bi-2.12.sys-

关键词： Bi2.r2.a1-xYxCu2.y substitution structural transformation.

Kinetic Process and Conductivity of Ag^+ Ion Exchange for Polycrystalline Na-β"-Al_2._3

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Journal of Materials science & Technology 1996年第4期12卷 315-317页

作者： Jianhua YANG(shanghai institute of Ceramics, {2. academy of Scieoces, shanghai 2.0050, china) shanghai institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

This paper reports the kinetic process of Ag ion exchange for the polycrystalline Na-β'-*** interdiffusion coefficients in the process of Ag+ and Na+ ion exchange have been calculated with an 'one dimensional double side diffusion model'. Microstructures of the samples were observed and analysed by XRD, EMPA, SEM. The results of the conductivity measurements for samples with Na+, Ag+ and Na+-Ag+ mobile ions are presented and explained

关键词： Kinetic Process and Conductivity of Ag Ion Exchange for Polycrystalline Na Al2.3

Development of solar-blind AlGaN 12.x12. Ultraviolet Focal Plane Arrays

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science china(Technological sciences) 2008年第6期51卷 820-826页

作者： YUAN YongGang1, ZHANG Yan1, CHU KaiHui1, LI XiangYang1, ZHAO DeGang2.& YANG Hui2.1 State Key Laboratories of Transducer Technology, shanghai institute of {2. physics, chinese academy of sciences, shanghai 200083, 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 China institute of Semiconductors Chinese Academy of Sciences Beijing China

This paper reports the development of solar-blind aluminum gallium nitride (AlGaN) 12.×12. UV Focal Plane Arrays (FPAs). The back-illuminated hybrid FPA archi- tecture consists of an 12.x12. back-illuminated AlGaN PIN detector array that is bump-mounted to a matching 12.x12. silicon CMOS readout integrated circuit (ROIC) chip. The 12.×12. 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

Ni2. treatment causes cement gland formation in ectoderm explants of Xenopus laevis embryo

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Cell Research 1999年第1期9卷 71-76页

作者： HUANG YONG XIAO YAN DING (shanghai institute of Cell Biology,{2., shanghai 2.0031, china) shanghai institute of Cell Biology Chinese Academy of Science Shanghai China

We found T-type calcium channel blocker Ni2. can efficiently induce the formation of cement gland in Xenopus laevis animal cap explants. Another T-type specific calcium channel blocker Amiloride can also induce the formation of cement gland, while L-type specific calcium channel blocker Nifedipine has no inductive effect. These results may offer us an new approach to study the differentiation of cement gland through the change of intracelluax calcium concentration.

关键词： Ni2. cement gland gastrulation T-type calcium channel

Structural and optical characteristics of Al_xGa_(1-x)N/AlN superlattice

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science china(Technological sciences) 2009年第2期52卷 332-335页

作者： XIE ZiLi1, ZHANG Rong1, JIANG RuoLian1, LIU Bin1, GONG HaiMei2. XIU XiangQian1, CHEN Peng1, LU Hai1, HAN Ping1, SHI Yi1 & ZHENG YouDou1 1 Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, Physical Department of Nanjing University, Nanjing 2.0093, china 2.shanghai {2. of technical physics, chinese academy of science, shanghai 200083, china Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials Physical Department of Nanjing University Nanjing China shanghai institute of {2. physics Chinese Academy of Science Shanghai China

AlN/Al0.3Ga0.7N superlattices were grown on (0001) sapphire substrate by metal-organic chemical vapor deposition (MOCVD). The superlattice period varies from 6 to 30. The layer thickness of different period stack was designed. GaN or AlGaN template was employed for growing AlN/AlGaN superlattices. Reflectivity, SEM, AFM and XRD data of the AlxGa1-xN/AlN superlattices are presented. It is found that the templates used have an intensive impact on surface roughness and interfacial properties of following AlN/AlGaN superlattices. The result of atomic force microscopy indicates that AlN/AlGaN superlattices grown on GaN template exhibit quasi-two-dimensional growth mode. The resulting superlattice has a smooth surface morphology and distinct interface. No crack is observed in the area of a 2.inch wafer.

关键词： MOCVD superlattices AlxGa1-xN/AlN

Cytotoxicity of carbon nanotubes

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science china Chemistry 2008年第11期51卷 1021-1029页

作者： ZHU Ying1,2.& LI WenXin1 1 Laboratory of Nano-biology and Medicine, shanghai institute of Applied {2., chinese academy of sciences, shanghai 2.1800, china 2.Graduate School of chinese academy of sciences, Beijing 100049, china Laboratory of Nano-biology and Medicine Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai China Graduate School of chinese academy of sciences Beijing China

With large-scale production and application at large scale, carbon nanotubes (CNTs) may cause ad-verse response to the environment and human health. Thus, study on bio-effects and safety of CNTs has attracted great attention from scientists and governments worldwide. This report briefly summa-rizes the main results from the in vitro toxicity study of CNTs. The emphasis is placed on the descrip-tion of a variety of factors affecting CNTs cytotoxicity, including species of CNTs, impurities contained, lengths of CNTs, aspect ratios, chemical modification, and assaying methods of cytotoxicity. However, experimental information obtained thus far on CNTs' cytotoxicity is lacking in comparability, and some-times there is controversy about it. In order to assess more accurately the potential risks of CNTs to human health, we suggest that care should be taken for issues such as chemical modification and quantitative characterization of CNTs in cytotoxicity assessment. More importantly, studies on physical and chemical mechanisms of CNTs' cytotoxicity should be strengthened; assaying methods and evaluating criteria characterized by nanotoxicology should be gradually established.

关键词： carbon nanotubes (CNTs) cell bio-security