检索结果-南通市图书馆

Difference discrete connection and curvature on cubic lattice

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2006年第11期49卷 1458-1476页

作者： WU Ke, ZHAO Weizhong & GUO Hanying Department of Mathematics, Capital Normal University, Beijing 10003., china Institute of theoretical physics, {3., Beijing 100080, china 1. Department of Mathematics Capital Normal University Beijing 100037 China 2. Institute of theoretical physics Chinese Academy of Sciences Beijing 100080 China

In a way similar to the continuous case formally, we define in different but equivalent manners the difference discrete connection and curvature on discrete vector bundle over the regular lattice as base space. We deal with the difference operators as the discrete counterparts of the derivatives based upon the differential calculus on the lattice. One of the definitions can be extended to the case over the random lattice. We also discuss the relation between our approach and the lattice gauge theory and apply to the discrete integrable systems.

关键词： discrete connection, discrete curvature, noncommutative calculus, lattice gauge theory, discrete Lax pair.

Calculation of the Surface Segregation of Cu-0.3.at. pct Au Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2000年第6期16卷 639-640页

作者： Liping ZHENG and Risheng LI (International center for Material physics, chinese academy of sciences, Shenyang 110015, {3.) Yuanxun ZHANG and Shi QIU (Shanghai Institute of Nuclear Research, chinese academy of sciences, Shanghai 201800, {3.) Bingyao JI Int. Cent. for Material Phys. Chinese Acad. of Sci. Shenyang 110015 China

Monte Carlo simulation technique with the energetics described by the embedded atom method has been used to calculate the surface segregation of Cu-0.3.at. pct Au alloy at T=800 K. It is found that the component Au in... 详细信息

关键词： Cu Calculation of the Surface Segregation of Cu-0.3.at pct Au Alloy

Dynamics of morphological changes for mitochondrial fission and fusion

在线全文

学校读者我要写书评

暂无评论

science china(physics,Mechanics & Astronomy) 2010年第4期53卷 680-689页

作者： WANG ShiQi 1,2,4 , FU ChangLiang 1,2 , ZHANG Yan 1,2 , CHEN Quan 3.& LONG Mian 1,2 1 Key Laboratory of Microgravity (National Microgravity Laboratory), Beijing 100190, china 2 center for Biomechanics and Bioengineering, Institute of Mechanics, chinese academy of sciences, Beijing 100190, china 3.State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, chinese academy of sciences, Beijing 100101, china 4 Institute of Vertebrate Paleontology and Paleoanthropology, chinese academy of sciences, Beijing 100044, china 1. Key Laboratory of Microgravity (National Microgravity Laboratory) Beijing 100190 China2. Center for Biomechanics and Bioengineering Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China4. Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China3. State Key Laboratory of Biomembrane and Membrane Biotechnology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China

Mitochondria experience continuous fusion and fission in a living cell, but their dynamics remains poorly quantified. Here a theoretical model was developed, upon a simplified population balance equation (PBE), to predict the morphological changes induced by mitochondrial fission and fusion. Assuming that both fission and fusion events are statistically independent, the survival probability of mitochondria staying in the fission or fusion state was formulated as an exponentially-decayed function with time, which depended on the time-dependent distribution of the mitochondrial volume and the fission and fusion rates. Parametric analysis was done for two typical volume distributions. One was Gamma distribution and the other was Gaussian distribution, derived from the measurements of volume distribution for individual mitochondria in a living cell and purified mitochondria in vitro. The predictions indicated that the survival probability strongly depended on morphological changes of individual mitochondria and was inversely correlated to the fission and fusion rates. This work provided a new insight into quantifying the mitochondrial dynamics via monitoring the evolution of the mitochondrial volume.

关键词： mitochondria morphology fission fusion dynamics modeling

Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2005年第S2期48卷 145-160页

作者： XIN Xiaozhou1,2, LIU Qinhuo1, TANG Yong1,3. TIAN Guoliang1, GU Xingfa1, LI Xiaowen1,2, ZHENG Hongsheng4 & CHEN Jiayi4 1. State Key Laboratory of Remote Sensing science, Institute of Remote Sensing Applications, chinese academy of sciences, Beijing 100101, china 2. Research {3. for Remote Sensing and GIS, Department of Geography, Beijing Normal University, Beijing 100875, china 3. Graduate University of chinese academy of sciences, Beijing 10003., china 4. Department of Atmospheric physics, Peking University, Beijing 100871, china 1. State Key Laboratory of Remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China2. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China3. Graduate University of Chinese Academy of Sciences 100039 Beijing China4. Department of Atmospheric Physics Peking University 100871 Beijing China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02 data were used to produce land use class of Baiyangdian area, Hebei Province, china in the autumn of 2004. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

Three-dimensional decomposition method of global atmospheric circulation

在线全文

学校读者我要写书评

暂无评论

science china Earth sciences 2008年第3期51卷 386-402页

作者： LIU HaiTao1,2,3. HU ShuJuan4, XU Ming5 & CHOU JiFan6,7 1 State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics, Institute of Atmospheric physics, chinese academy of sciences, Beijing 100029, {3. 2 Graduate University of chinese academy of sciences, Beijing 100049, {3. 3.Beijing Climate center, Beijing 100089, {3. 4 Department of Mathematics, Lanzhou University, Lanzhou 73.000, {3. 5 Shanghai Typhoon Institute, Shanghai 20003., {3. 6 Department of Atmospheric sciences, Lanzhou University, Lanzhou 73.000, {3. 7 {3. Meteorological Administration Training center, Beijing 100089, {3. 1. State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Graduate University of chinese academy of sciences Beijing 100049 China 3. Beijing Climate center Beijing 100089 China 4. Department of Mathematics Lanzhou University Lanzhou 730000 China 5. Shanghai Typhoon Institute Shanghai 200030 China 6. Department of Atmospheric sciences Lanzhou University Lanzhou 730000 China 7. china Meteorological Administration Training center Beijing 100089 China

By adopting the idea of three-dimensional Walker, Hadley and Rossby stream functions, the global atmospheric circulation can be considered as the sum of three stream functions from a global perspective. Therefore, a m... 详细信息

关键词： three-dimensional decomposition of the global atmospheric circulation generalized Walker Hadley and Rossby stream functions existence and uniqueness vertical motion

An Explicit Function Expression for dc Bias and Temperature Dependence of Magnetoresistances in Magnetic Tunnel Junctions

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2002年第6期18卷 497-501页

作者： Xiufeng HANState Key Laboratory of Magnetism, Institute of physics and center of Condensed Matter physics, {3., Beijing 100080, china chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China chinese Acad Sci Ctr Condensed Matter Phys Beijing 100080 Peoples R China

An explicit function expression for the bias voltage or/and temperature dependences of tunnel magnetoresistance ratio and resistances were obtained with a unique set of intrinsic parameters. Two of these intrinsic parameters are the Curie temperature TC and the density of state (DOS) for itinerant majority and minority electrons ξ(ρM/ρm), which are the eigen parameters of ferromagnetic electrodes. Others are the spin-dependent matrix-element ratio (i.e., |Td|2/|TJ|2 ) and the anisotropic-wavelength-cutoff energy ECγ of spin-wave spectrum in magnetic tunnel junction (MTJ), which are the structure parameters of an MTJ. These intrinsic parameters can be predetermined using the experimental measurement or, in principle, using the first-principle calculation method for an MTJ with the three key layers of FM/I/FM. Furthermore, a series of experimental data for an MTJ, for example, a spin-valve-type MTJ of Ta (5 nm)/Ni79Fe21(25 nm)/lr22Mn78(12 nm)/Co75Fe25(4 nm)/AI(0.8 nm)-oxide/Co75Fe25(4 nm)/Ni79Fe21(20 nm)/Ta (5 nm) in this work, can be self-consistently evaluated and explained using such concise explicit function formulations.

关键词： Magnetic tunnel junction TMR Spin-electron transport Magnon excitation Spin-polarization Magnetotransport

Further research on high-spin structure in ^(161)Lu

在线全文

学校读者我要写书评

暂无评论

science china(physics,Mechanics & Astronomy) 2008年第3期51卷 315-320页

作者： LI YanXia1,2,YU ShaoYing1,2,4,SHEN CaiWan1,5,LI XiaoWei6 & CHEN YongShou3.4 1 School of science,Huzhou Teachers College,Huzhou 3.3.00,china 2 College of Mathematics,physics and Information Engineering,Zhejiang Normal University,Jinhua 3.1000,china 3.china Institute of Atomic Energy,Beijing 102413.china 4 Institute of theoretical physics,chinese academy of sciences,Beijing 100080,china 5 center of theoretical Nuclear physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 73.000,china 6 Department of physics,Chifeng University,Chifeng 024001,china School of science Huzhou Teachers College Huzhou 313000 China College of Mathematics Physics Information Engineering Zhejiang Normal University Jinhua 321000 China china Institute of Atomic Energy Beijing 102413 China Institute of theoretical physics Chinese Academy of Sciences Beijing 100080 China center of theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China Department of physics Chifeng University Chifeng 024001 China

The two-dimensional total routhian surface (TRS) calculations were performed to probe into the triaxial superdeformed characteristics of a strongly populated band X2 in 161Lu. This band was identified as a triaxial superdeformed band by using our TRS method. We also got its formation mechanics,i.e. the neutron-shell correction energy plays a crucial role,while the rotating energy and the deformation-driving effect of high j intruder orbit i13.2 also play an additional role.

关键词： TRS method triaxial superdeformation formation mechanism

Bifurcation timescales in power spectra of black hole binaries and ultraluminous X-ray sources

在线全文

学校读者我要写书评

暂无评论

science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 177-182页

作者： WANG TaiShan1 & LI TiPei1,2 1 Department of physics & center for Astrophysics,Tsinghua University,Beijing 100084,{3. 2 Key Laboratory of Particle Astrophysics,Institute of High Energy physics,chinese academy of sciences,Beijing 100049,{3. Tsinghua Univ Dept Phys Beijing 100084 Peoples R China Tsinghua Univ Ctr Astrophys Beijing 100084 Peoples R China chinese Acad Sci Inst High Energy Phys Key Lab Particle Astrophys Beijing 100049 Peoples R China

For black hole binaries(BHBs) and active galactic nuclei(AGNs),bifurcation timescales(BTs) Δtb exist,below which time-domain power is significantly higher than the corresponding Fourier ***-periodic oscillations(QPOs) are removed from the Fourier spectra of BHBs.A relationship between BT,black hole mass and bolometric luminosity is *** anti-correlation between BT and luminosity of Cyg X-1 is *** removing the QPOs,BTs are also obtained for two ultraluminous X-ray sources(ULXs),M82 X-1 and NGC5408 *** results support that they harbor intermediate mass black holes(IMBHs).

关键词： black hole binary ultraluminous X-ray source power spectral density data analysis

Nucleon Form Factors and N-A Transitions in a Hypercentral Constituent Quark Model with Meson Cloud

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical physics 2007年第3期 539-546页

作者： CHEN Dina-Yong~(1,2) DONG Yu-Bing~(1,+)1 Institute of High Energy physics,the chinese academy of sciences,Beijing 100049,{3.2 Graduate School of the chinese academy of sciences,Beijing 100049,{3. Institute of High Energy physics，the chinese academy of sciences，Beijing 100049，{3. Graduate School of the chinese academy of sciences，Beijing 100049，china Institute of High Energy physics，the chinese academy of sciences，Beijing 100049，{3.

We study the nucleon form factors and the nucleon-△(123.)transitions in a framework of hypercentralconstituent quark *** pion meson cloud effect is taken into account *** results show that the pioncloud contributes substantially to the nucleon form factors as well as to the helicity amplitudes of △(123.),and it givesan improved agreement compared to the experimental measurement.

关键词： electromagnetic form factor nucleon and △(123.) hypercentral constituent quark model meson cloud