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A one-dimensional heat transfer model of the Antarctic Ice Sheet and modeling of snow temperatures at Dome A, the summit of Antarctic Plateau

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Science china Earth sciences 2010年第5期53卷 763-772页

作者： CHEN BaiLian1,3, ZHANG RenHe2. SUN ShuFen1, BIAN LinGen2. XIAO CunDe4,2.& ZHANG TingJun5 1 institute of Atmospheric physics, {2. Academy of sciences, beijing 10002., china 2.{2. Academy of Meteorological sciences, beijing 100081, china 3 Graduate University of {2. Academy of sciences, {12., china 4 Cold and Arid Regions Environmental and Engineering Research institute, {2. Academy of sciences, Lanzhou 730000, china 5 The National Snow and Ice Data Center, University of Colorado, Boulder, CO 80309-0449, USA 1. institute of Atmospheric physics Chinese Academy of Sciences Beijing 100029 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Chinese Academy of Meteorological Sciences Beijing 100081 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China5. The National Snow and Ice Data Center University of Colorado Boulder CO 80309-0449 USA

A vertical one-dimensional numerical model for heat transferring within the near-surface snow layer of the Antarctic Ice Sheet was developed based on simplified parameterizations of associated physical processes for the atmosphere, radiation, and snow/ice systems. Using the meteorological data of an automatic weather station (AWS) at Dome A (80°2.′S, 70°2.′E), we applied the model to simulate the seasonal temperature variation within a depth of 2. m. Comparison of modeled results with observed snow temperatures at 4 measurement depths (0.1, 1, 3, 10 m) shows good agreement and consistent seasonal variations. The model results reveal the vertical temperature structure within the near-surface snow layer and its seasonal variance with more details than those by limited measurements. Analyses on the model outputs of the surface energy fluxes show that: 1) the surface energy balance at Dome A is characterized by the compensation between negative net radiation and the positive sensible fluxes, and 2. the sensible heat is on average transported from the atmosphere to the snow, and has an evident increase in spring. The results are considered well representative for the {2.est interior Antarctic Plateau.

关键词： Antarctic Ice Sheet near-surface layer energy transfer numerical model

β-delayed proton decays near the proton drip line

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2., CHEN Yongshou 2., XU Furong 3 , WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. institute of Modern physics, {2. Academy of sciences, Lanzhou 730000, china 2. Nuclear physics Department, china institute of Atomic energy, beijing 102.13, china 3. Department of Technical physics, Peking University, beijing 100871, china 4. Shanghai institute for Nuclear Research, Shanghai 2.1800, china 1. institute of Modern physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear physics Department China Institute of Atomic Energy 102413 Beijing China 3. Department of Technical physics Peking University 100871 Beijing China 4. Shanghai institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2.04, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92.h as well as the predicted “waiting point” nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2. The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142.o and 12.Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

A Study of Electromagnetic Transition of Δ(12.2.Resonance

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Communications in Theoretical physics 2004年第7期 87-89页

作者： DONG Yu-Bing LIU Jian institute of high {2. physics, the chinese Academy of sciences, beijing 100039, china

Point form relativistic dynamics of relativistic quantum mechanics is employed to estimate the photonand electroproduction amplitudes of Δ(12.2. *** are compared with the non-relativistic work,and thedifferences betw... 详细信息

关键词： relativistic quantum mechanism point form dynamics

CHEMICAL STRUCTURE DEPENDENCE OF THE INTERNAL energy CONTRIBUTION IN RUBBER ELASTICITY

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chinese Journal of Polymer Science 2001年第5期19卷 447-449页

作者： Juan Sun Xiao-zhen Yang Polymer physics Laboratory Center for Molecular sciences, {2. of Chemistry chinese Academy of sciences beijing 100080 china chinese Acad Sci Polymer Phys Lab Ctr Mol Sci Inst Chem Beijing 100080 Peoples R China

Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene). Calculated f(e)/f values are in good agreement with those obtained experimentally. Results show that behavior of f(e)/f is mainly contributed by chemical structure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution is strain dependent.

关键词： conformational elasticity theory internal energy contribution poly(cis-1,4-isoprene) poly(trans-1,4-isoprene)

Evolution of desertification in a two-dimensional energy balance model coupled with thermodynamics and dynamics

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Science china Earth sciences 2010年第11期53卷 1726-1733页

作者： CHAO JiPing1,2.& LI YaoKun3,4 1National Marine Environmental Forecasting Center, beijing 100081, china 2.irst {2. of Oceanography, State Oceanic Administration, Qingdao 2.6061, china 3State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics, {2. of Atmospheric physics, chinese Academy of sciences, beijing 10002., china 4Graduate University of chinese Academy of sciences, beijing 100049, china 1. National Marine Environmental Forecasting Center Beijing 100081 China2. First Institute of Oceanography State Oceanic Administration Qingdao 266061 China3. State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China4. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The relationship between desert evolution and change in albedo has been investigated quasi-analytically using a zonal mean two-dimensional energy balance model which considers the radiation transmission process due to thermodynamics and bound- ary layer movement caused by kinetics. A climate state including temperature, zonal wind, meridional wind and vertical wind can be simulated according to the current zonal distribution of albedo. Given desert distribution, characterized by the value and distribution of albedo, the response of climate on albedo has been studied to analyze the evolution of desert climate. One significant result is that the simple model can reproduce mean meridional circulation. Another result indicates that climate corresponds to two equilibria. This happens when the junction temperature between vegetation and desert is higher than a certain critical value. As for the first equilibrium, the desert belt is predicted to move southward in the northern hemisphere with the increasing values of albedo, which corresponds to the current trend of climate change. For the second equilibrium, vegetation will expand northward with increasing values of albedo, which would indicate a narrowing of the desert belt. In order to determine if the two equilibria exist, new physical models are needed.

关键词： two-dimensional energy balance model desertification two equilibria

IMAGING IN high energy ASTRONOMY

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空间科学学报 1998年第S1期18卷 12-20页

作者： LI Ti-pei (institute of high Enerpy {2., The chinese Academy of sciences, beijing 100039)

Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain high resolution results from space observations. It is a difficult task to make observations with both high sensitivity and high resolution. Applying advanced inversion technique, one can subtract more information from old data in public domain,and, furthermore, conduct high sensitive and high-resolution experiments with low-cost low-resolution instruments. So developing and applying data analysis technique is of great importance for developing countries to do basic space *** this paper we summarize efforts of chinese scientists in recent years along this direction on imaging in space high energy astronomy.

关键词： Space astronomy Astronomical satellite Imaging

Isospin-dependent relativistic microscopic optical potential in the Dirac Brueckner-Hartree-Fock method

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Science china(physics,Mechanics & Astronomy) 2004年第2期47卷 189-198页

作者： RONG Jian1 & MA Zhongyu1,2.3.1. china {2. of Atomic energy, beijing 102.13, china 2. Center of Nuclear Theoretical physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lan-zhou 730000, china 3. {2. of Theoretical physics, chinese Academy of sciences, beijing 100080, china Correspondence should be addressed to Rong Jian (email: jrong@***) 1. china institute of Atomic {2. 102413 Beijing China 2. Center of Nuclear Theoretical physics National Laboratory of Heavy Ion Accelerator of Lanzhou 730000 Lanzhou China 3. institute of Theoretical physics Chinese Academy of Sciences 100080 Beijing China

The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-energy in nuclear matter is adopted. The self-energy of a nucleon with E > 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-energy. The energy and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the energy dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.

关键词： Dirac Brueckner Hartree-Fock, relativistic microscopic optical potential, asymmetric nuclear matter, isospin-dependence.

The time lag spectrum of Cir X-1 on its normal branch

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 60-63页

作者： QU JinLu1,LU Yu1,2.DING GuoQiang3,ZHANG Fan1,LEI YaJuan1 & LI ZhiBing1 1 Key Laboratory for Particle Astrophysics,institute of {2. energy physics,chinese Academy of sciences,beijing 100049,china 2.Graduate University of chinese Academy of sciences,beijing 100049,china 3 Urumqi Observatory,NAOC Urumqi 830011,china 1. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Urumqi Observatory NAOC Urumqi 830011 China

In the radiation-hydrodynamics model,the time lag and fractional root-mean-squared(rms) amplitude as a function of emitted photon energy should show a minimum on the normal branch *** has been seen in the Z-sources Cyg X-2.and GX ***,using the observations from the Rossi X-ray Timing Explorer(RXTE),we study the energy dependence of normal branch QPOs in the peculiar Z-source Cir *** discuss the results in the context of radiation-hydrodynamics and the Comptonization model.

关键词： Cir X-1 temporal variability QPO time lag

Structural stability of infinite-layer CaCuO_2.under high pressure

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chinese Science Bulletin 2003年第12期48卷 1201-1203页

作者： QIN Xiaomei1,2. HONG Ming1,2. ZHANG Gongmu1,2. MAI Wenjie1,2. LI Fengying1,2. YU Richeng1,2. LIU Jing2.3.& JIN Changqing1,2.1. institute of {2., chinese Academy of sciences, beijing 100080, china 2. beijing high Pressure Research Center, beijing 100080, china 3. institute of high energy {2., chinese Academy of sciences, beijing 100039, china Correspondence should be addressed to Jin Changqing (e-mail: cqjin@ ***) institute of physics Chinese Academy of Sciences Beijing 100080 China beijing high Pressure Research Center Beijing 100080 China institute of high {2. physics Chinese Academy of Sciences Beijing 100039 China

In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder Ca-CuO2.with an infinite layer structure (IL CaCuO2. have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results suggest that the crystal structure of IL CaCuO2.is stable under pressure up to 30 GPa at room temperature. According to Birch-Murn- aghan equation of state, assuming pressure derivative 4,=0Bthe bulk modulus B0=181 ?9 GPa is obtained.

关键词： infinite-layer CaCuO2 synchrotron radiation high pressure energy dispersive X-ray diffraction.