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Response synchronization: New progress in brain-visual information processing

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chinese Science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIONG Xiaoyun, YAO Guozheng and GUO Aike1. State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry , institute of Atmospheric physics ,{3. , beijing 10002., china 2. Commission of the National Natural Science Foundation of china , beijing 100083. china 3. The center of Information Science , Peking University, beijing 100871, china 4. Open Laboratory of Visual Information Processing , institute of Biophysics ,{3. , beijing 100101, china State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the National Natural Science Foundation of china Beijing China The center of Information Science Peking University Beijing China Open Laboratory of Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.

High resistance modulation by the electric field based on La_(0.9)Sr_(0.1)MnO_3.SrTiO_3.Si structure

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Science china(physics,Mechanics & Astronomy) 2009年第9期52卷 1299-1301页

作者： YANG Fang, HE Meng, WEN Juan, JIN KuiJuan, LU HuiBin & YANG GuoZhen beijing National Laboratory for condensed Matter {2.,{3., chinese academy of sciences, beijing 100190, china beijing National Laboratory for condensed Matter {2. Institute of Physics Chinese Academy of Sciences Beijing China

A field-effect configuration based on La0.9Sr0.1MnO3.SrTiO3.Si structure is fabricated on Si substrate by laser molecular-beam epitaxy. The resistance modulation by electric field of the La0.9Sr0.1MnO3.SrTiO3.Si structure is investigated in detail. An evident resistance modulation effect is observed at 80 K. The channel resistance modulation by field effect reaches 1.4×107% and 2.6×106% when VDS are -2.and -6.5 V, respectively. The ON/OFF ratio of approximately 4000 is obtained. The present results are worthy of further investigations for potential applications of resistance modulation by electrostatic field in the heterostructures consisting of perovskite oxides and Si.

关键词： field effect perovskite oxide thin films resistance modulation

PHASE EXTENSION AND STRUCTURE ANALYSIS BY THE MAXIMUM ENTROPY METHOD

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Acta Metallurgica Sinica(English Letters) 1998年第4期11卷 241-254页

作者： G.B.Hu and Q.B.Yang (Department of physics, Xiangtan University, Xiangtan 411105, china)({2. Laboratory of Electron Microscopy, {3. for condensed Matter physics, The chinese academy of sciences, P. O. Box 2.2., beijing 100080, china) Xiangtan Univ Xiangtan China

Excellent results are obtained in structure analysis with jew phases of structure factors by the maximum-entropy method (MEM) for CaGaN PbCO3.and ReBe2. single crystals. The computation time and memory space are minim... 详细信息

关键词： maximum entropy method structure analysis phase extension,symmetry

TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

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chinese Journal of Polymer Science 2000年第1期18卷 51-55页

作者： Wei Huang Ying Huang Yunzhao Yu center for Molecular Science, institute of Chemistry,{2.,{3., china 中科院化学所北京

Trimethylsilylated silica was synthesized. through hydrolytic condensation of tetraethoxysilane followed by trimethylsilylation. Rheological properties of the silicone resin with trimethylsilylated silica as modifier were studied. It turned out that the particle size of silica was important to the rheological behavior of the modified resin. Trimethylsilylated silica of medium particle size shows the strongest tendency of forming physical network in the resin.

关键词： silica trimethylsilylation rheology modifier silicone resins

Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science china Earth sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1,2.3.& DING YiHui2.1 chinese {3. of Meteorological {2., beijing 100081, china 2.National Climate center, beijing 100081, china 3.Graduate University of chinese academy of sciences, beijing 100049, china chinese academy of Meteorological {2. Beijing China National Climate center Beijing China Graduate University of chinese academy of sciences Beijing China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern china. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South china Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

High-pressure and high-tem-perature synthesis of MgB_2.and its superconductivity

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chinese Science Bulletin 2001年第22期46卷 1932-1934页

作者： ZHU Jialin, LI Shaochun, YU Richeng, LI Fengying LIU Zhengxing & JIN ChangqingLaboratory for Extreme Condition physics, institute of physics, {2. for {3. Matter Physcis and beijing High Pressure Research {2., chinese academy of sciences, beijing 100080, china Laboratory for Extreme Condition physics Institute of Physics Center for Condensed Matter Physcis and Beijing High Pressure Research Center Chinese Academy of Sciences Beijing China

The single-phase sample of MgB2.was prepared successfully at the temperature of 900℃ and under the pressure of 3.GPa. The structure of the sample was investigated using powder X-ray diffraction and Rietveld analysis. The results show that the structure of the sample belongs to the hexagonal structure with space group of P6/mmm, a=3.0861(5) A, c=3.52.2.8) A. The magnetic and resistance measurements indicate that the superconducting transition temperature Tc is 3. K.

关键词： superconductivity magnetization resistance.

Inconsistency between WMAP data and released map

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chinese Science Bulletin 2010年第10期55卷 907-909页

作者： LIU Hao1 & LI TiPei1,2.3.1 Key Laboratory of Particle Astrophysics,institute of High Energy physics,chinese academy of sciences,beijing 100049,china 2.Department of physics & center for Astrophysics,Tsinghua University,beijing 100084,china 3.Department of Engineering physics & center for Astrophysics,Tsinghua University,beijing 100084,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Department of physics & center for Astrophysics Tsinghua University Beijing China Department of Engineering physics & center for Astrophysics Tsinghua University Beijing China

A remarkable inconsistency between the calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission,which is the input for map-making,and the cosmic microwave background (CMB) temperature maps published by the WMAP team is revealed,indicating that there must exist a serious problem in the map making routine of the WMAP *** inconsistency is easy to be confirmed without the use of WMAP map-making *** view of the importance of this issue for cosmology study,we invite readers to check it by themselves.

关键词：威尔金森微波各向异性探测器 WMAP 地图制作宇宙微波背景有序数据制作软件 TOD CMB

Prediction method for October 2.03.solar storm

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Science china(Technological sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2. 3. WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2.1. State Key Laboratory of Space Weather, center for Space Science and Applied Research,{3.,{2., china 2. Graduate School,{3., beijing 10003., china 3. institute of Meteorology, PLA University of Science and Technology, Nanjing 2.1101, china State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China institute of Meteorology PLA University of Science and Technology Nanjing China

Aiming at two intense shock events on October 2. and 2., 2.03. this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

EFFECT OF PARTICLE SIZE ON THE FILMING PROCESS OF POLYSTYRENE LATEX STUDIED BY AFM

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chinese Journal of Polymer Science 2002年第6期20卷 509-515页

作者： Xiao-zhong Qu Yi Shi Liu-sheng Chen Xi-gao Jin State Key Laboratory of Polymer physics & Chemistry, center for Molecular Science,{2. of Chemistry,{3., beijing 100080 china State Key Lab. of Polymer Phy./Chem. Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The film formation process of micro-PS particles (diameter 742.nm) and nano-PS particles (diameter 2. nm) was studied by atomic force microscopy and differential scanning calorimetry. During a step heating process, the particles were annealed for 0.5 h at each selected temperature. It was found that the deformation and interdiffusion temperatures of the micro-PS particles are ca. 12.-13.degreesC and 140-150degreesC, that of the nano-PS particles are 90degreesC and 100-110degreesC respectively. The DSC traces of nano-PS particles showed that there was an exothermic peak near T-g after annealing for 0.5 h at the selected temperatures below 90degreesC; otherwise, the exothermic peak disappeared after annealing at 100degreesC or above. Compared with the micro-PS particles, the sintering process of nano-PS particles occurs at much lower temperature determined by the confined state of polymer chains with higher conformational energy in nano-particles, and completes in a much narrower temperature range driven mainly by the larger total surface energy.

关键词： polystyrene latex filming process particle size effect