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Bursting of Morris-Lecar neuronal model with current-feedback control

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Science china(Technological Sciences) 2009年第3期52卷 771-781页

作者： DUAN LiXia1, LU QiShao2 & CHENG DaiZhan3 1 College of Science, North china University of Technology, beijing 100144, china 2 School of Science, beijing University of Aeronautics and Astronautics, beijing 100191, china 3 institute of Systems Science, Chinese Academy of Sciences, beijing 100190, china College of Science North China University of Technology Beijing 100144 China School of Science Beijing University of Aeronautics and Astronautics Beijing 100191 China institute of Systems Science Chinese Academy of Sciences Beijing 100190 China

The Morris-Lecar (ML) neuronal model with current-feedback control is considered as a typical fast-slow dynamical system to study the combined influences of the reversal potential VCa of Ca2+ and the feedback current I on the generation and transition of different bursting oscillations. Two-parameter bifurcation analysis of the fast subsystem is performed in the parameter (I, VCa)-plane at first. Three important codimension-2 bifurcation points and some codimension-1 bifurcation curves are obtained which enable one to determine the parameter regions for different types of bursting. Next, we further divide the control parameter (V0, VCa)-plane into five different bursting regions, namely, the "fold/fold" bursting region R1, the "fold/Hopf" bursting region R2, the "fold/homoclinic" bursting region R3, the "subHopf/homoclinic" bursting region R4 and the "subHopf/subHopf" bursting region R5, as well as a silence region R6. Codimension-1 and -2 bifurcations are responsible for explanation of transition mechanisms between different types of bursting. The results are instructive for further understanding the dynamical behavior and mechanisms of complex firing activities and information processing in biological nervous systems.

关键词： neuron bursting bifurcation fast-slow dynamics analysis codimension

Observation of signature inversion in the πh_(9/2)(×)νi_(13/2) oblate band

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 442-449页

作者： XIE Chengying1,2, ZHOU Xiaohong1,2, ZHANG Yuhu1, GUO Yingxiang1, LEI Xiangguo1, ZHENG Yong1, LIU Minliang1, SONG Litao1, WANG Hualei1, YU Haiping1, GUO Wentao 1, LUO Peng1, WU Zhijun1, ZHU Lihua3 & WU Xiaoguang3 ⒈ institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, china ⒉ Graduate School of the Chinese Academy of Sciences, beijing 100049, china ⒊ institute of atomic energy Research, beijing 1024.3, china institute of Modern Physics Chinese Academy of Sciences Lanzhou China Graduate School of the Chinese Academy of Sciences Beijing China institute of atomic energy Research Beijing China

High-spin states in 190Tl have been studied via the 160Gd(35Cl, 5nγ) reaction. The level scheme, consisting of the π h9 /2 νi13/2 oblate band and a cascade with character of single particle excitations, has been established. Spin values have been firmly assigned to the oblate band in 190Tl, resulting in low-spin signature inversion in the π h9 /2 νi13/2 oblate band for the first time. Based on the similarity of the level structure in doubly odd Tl nuclei, spin values for the oblate bands in 192―200Tl should be re-assigned, and a consistent low-spin signature inversion has occurred in these oblate deformed nuclei. The low-spin signature inversion phenomena can be interpreted qualitatively by using the 2-quasiparticle plus rotor model including p-n residual interactions.

关键词： deformed odd-odd 190Tl, oblate rotational bands, signature inversion, 2-qp+rotor model.

北京城市副中心0701街区D#地块住房百年住宅示范项目

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建筑实践 2024年第3期 96-103页

作者： china institute of Building Standard Design & Research Co., Ltd. 中国建筑标准设计研究院有限公司

北京城市副中心是规划建设疏解北京非首都功能、推动京津冀协同发展的历史性工程。项目对于落实首都城市战略定位、建设国际—流的和谐宜居之都,对于建设以首都为核心的世界级城市群,都具有十分重大而深远的意义。项目规划设计打破传统...

北京城市副中心是规划建设疏解北京非首都功能、推动京津冀协同发展的历史性工程。项目对于落实首都城市战略定位、建设国际—流的和谐宜居之都,对于建设以首都为核心的世界级城市群,都具有十分重大而深远的意义。项目规划设计打破传统封闭社区规划模式,以小街区密路网、开放式社区的设计骨架,用半围合式住宅,院落内外高差处理等设计手法打造和谐、有序而具有活力的多元示范住区。

关键词：

The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan

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Science china Earth Sciences 2005年第9期48卷 1329-1336页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2, TENG Jiwen1, Lü Qingtian3, LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4 1. institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 100029, china 2. institute of Geophysics, china Seismological Bureau, beijing 100085, china 3. institute of Deposition Resource, Chinese Academy of Geosciences, beijing 100037, china 4. School of Exploration and Information, china University of Geosciences, beijing 100083, china 1. institute of Geology and Geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of Geophysics China Seismological Bureau 100085 Beijing China 3. institute of Deposition Resource Chinese Academy of Geosciences 100037 Beijing China 4. School of Exploration and Information China University of Geosciences 100083 Beijing China

The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, china. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into 3 segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2 km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2 segments. In the studied area, crustal thickness is about 40 km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.

关键词： Sanjiang area wide-angle seismic profile crustal structure.

New evidence for lack of CMB power on large scales

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 567-570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 1. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Department of Physics & Center for Astrophysics Tsinghua University Beijing 100084 China3. Department of Engineering Physics & Center for Astrophysics Tsinghua University Beijing 100084 China

A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.

关键词： cosmology cosmic microwave background data analysis

Simulating　Experimental　Investigation　on　the　Safety　of　Nuclear　Heating　Reactor　in　Loss－of－Coolant　Accidents

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Journal of Thermal Science 1996年第4期5卷 285-291页

作者： Zhanjie Xu(institute of Nuclear energy Technology, Tsinghua University, beijing, 100084, china) institute of Nuclear energy Technology Tsinghua University Beijing China

The 5MW low temperature nuclear heating reactor (NHR-5) is a new and advanced type of nuclear reactor developed by institute of Nuclear energy Technology (INET) of Tsinghua University of china in 1989. Its main loop is a thermal-hydraulic system with natural circulation. This paper studies the safety of NHR under the condition of loss-of-coolant accidents (LOCAs) by means of simulant experiments. First, the background and necessity of the experiments are presented, then the experimental system, including the thermal-hydraulic system and the data collection system, and similarity criteria are introduced. UP to now, the discharge experiments with the residual heating power (20% rated heating power) have been carried out on the experimental system. The system parameters including circulation flow rate, system pressure, system temperature, void fraction, discharge mass and so on have been recorded and analyzed. Based on the results of the experiments, the conclusions are shown as folios: on the whole, the reactor is safe under the condition of LOCAs, but the thermal vacillations resulting from the vibration of the circulation flow rate are disadvantageous to the internal parts of the reactor core.

关键词： nuclear heating reactor natural circulation LOCA safety.

Kinetic characteristics of continuous flow polymerase chain reaction chip: A numerical investigation

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Science china(Technological Sciences) 2010年第7期53卷 1967-1972页

作者： WANG ShiYing1 & WANG Wei2,3 1 School of Physics, Peking University, beijing 100871, china 2 institute of Microelectronics, Peking University, beijing 100871, china 3 National Key Laboratory of Science and Technology on Micro/Nano Fabrication, beijing 100871, china 1. School of Physics Peking University Beijing 100871 China2. Institute of Microelectronics Peking University Beijing 100871 China3. National Key Laboratory of Science and Technology on Micro/Nano Fabrication Beijing 100871 China

Continuous flow PCR (polymerase chain reaction) chip holds impressive advantages compared to micro chamber PCR chip. In order to have better understanding of kinetic characteristics of continuous flow PCR chip, a comprehensive mathematical model is presented in this paper, including melting, annealing and extension phases of a typical PCR process which has the essence of a convection-diffusion-reaction system. Using this model, we can simulate the PCR process in series of reaction cycles. Numerical results show that the average sample velocity plays a significant role in affecting the amplification efficiency. Also, appropriate combination of the PCR mixture is important for high-quality DNA amplification. Giving a large initial DNA concentration range, the continuous flow PCR scheme holds excellent real-time detection ability theoretically. The present numerical model bridges the temperature distribution to the real DNA amplification, and thereby is able to successfully predict continuous flow PCR properties which are important for the chip design.

关键词： continuous flow PCR chip numerical simulation convection-diffusion-reaction system

Lithosphere types in North china:Evidence from geology and geophysics

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Science china Earth Sciences 2005年第11期48卷 1809-1827页

作者： QIU Ruizhao1,2, DENG Jinfu3, ZHOU Su3, LI Jinfa4, XIAO Qinghui1,5, WU Zongxu6 & LIU Cui3 1. institute of Geology, Chinese Academy of Geological Sciences, beijing 100037, china 2. Development and Research Center, china Geological Survey, beijing 100037, china 3. china University of Geosciences, beijing 100083, china 4. china University of Geosciences, Wuhan 430074, china 5. Information Center of Ministry of Land and Resources, beijing 100812, china 6. institute of Geology, State Seismological Bureau, beijing 100029, china 1. institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China 2. Development and Research Center China Geological Survey 100037 Beijing China 3. china University of Geosciences 100083 Beijing China 4. china University of Geosciences 430074 Wuhan China 5. Information Center of Ministry of Land and Resources 100812 Beijing China 6. institute of Geology State Seismological Bureau 100029 Beijing China

On the basis of the characteristics of geology and geophysics in North china, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North china platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North china Platform is a remnant of cratonic lithosphere after the North china platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North china craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North china platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North china in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the

关键词： lithospheric types,evidence of geology and geophysics,crust-mantle petrological structure,deep process

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电力变压器中的热工水力学问题及其实验研究

变压器 1997年第11期34卷 15-17页

作者： Ding Zhenxin (china institute of atomic energy, beijing 1024.3) 中国原子能科学研究院

概述了电力变压器中的热工水力学问题及其实验研究的内容，阐述了热工水力学实验的发展方向及其作用。

关键词：电力变压器热工水力学实验