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Constraints on smoothness parameter and dark energy using observational H(z) data

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Research in Astronomy and Astrophysics 2011年第2期11卷 125-136页

作者： Hao-Ran Yu1,Tian Lan1,Hao-Yi Wan2.Tong-Jie Zhang1,3.and Bao-Quan Wang4 1 Department of Astronomy,beijing Normal University,beijing 100875,{2. 2.Business Office,beijing Planetarium,beijing 100044,{2. 3.center for High Energy physics,Peking University,beijing 100871,{2. 4 Department of physics,Dezhou University,Dezhou 2.3.2.,{2. Department of Astronomy Beijing Normal University Beijing 100875 China Business Office Beijing Planetarium Beijing 100044 China center for High Energy physics Peking University Beijing 100871 China Department of physics Dezhou University Dezhou 253023 China

With large-scale homogeneity,the universe is locally inhomogeneous,clustering into stars,galaxies and larger *** property is described by the smoothness parameter α which is defined as the proportion of matter in the form of intergalactic *** we consider the inhomogeneities over a small scale,there should be modifications of the cosmological distances compared to a homogenous *** and Roeder developed a second-order ordinary differential equation（D-R equation） that describes the angular diameter distance-redshift relation for inhomogeneous cosmological ***,we may obtain the D-R equation for observational H（z） data（OHD）.The density-parameter ΩM,the state of dark energy ω,and the smoothness-parameter α are constrained by a set of OHD in a spatially flat XCDM universe as well as a spatially flat XCDM *** using a χ2.minimization method,we get α = 0.81＋0.19-0.2. and ΩM = 0.3.1}0.12.0.06 at the 1σ confidence *** we assume a Gaussian prior of ΩM = 0.2. ± 0.1,we get α = 0.93.0.07-0.19 and ΩM = 0.3.＋*** the XCDM model,α is constrained to α≥ 0.80 but ω is weakly constrained around-1,where ω describes the equation of state of the dark energy（pX = ωρX）.We conclude that OHD constrains the smoothness parameter more effectively than the data of SNe Ia and compact radio sources.

关键词： cosmology -- dark energy -- cosmological parameters

Theory study of shapes in ^(187,189)Tl nuclei

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Science china(physics,Mechanics & Astronomy) 2009年第6期52卷 818-821页

作者： LIU YanXin1, YU ShaoYing1,2.3. SHEN CaiWan1,5 & DONG YongSheng1,2.4 1 School of Science, Huzhou Teachers College, Huzhou 3.3.00, china 2.School of Science and Information Engineering, Zhejiang Normal University, Jinhua 3.0}000, china 3.{2. of Theoretical {3., Chinese Academy of Sciences, beijing 100080, china 4 Department of {3., Jining Teachers College, Jining 012.00, china 5 {13. of Theoretical Nuclear {3., National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 73.000, china School of Science Huzhou Teachers College Huzhou China School of Science and Information Engineering Zhejiang Normal University Jinhua China institute of Theoretical physics Chinese Academy of Sciences Beijing China center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China Department of physics Jining Teachers College Jining China

The nuclear shapes of 187,189Tl were investigated theoretically in this work. The total routhian surface (TRS) calculations were performed for N=106 and 108 isotopes of thallium (Z=81). The single-particle energies were obtained from the deformed Woods-Saxon potential, with the Lipkin-Nogami (LN) treatment of pairing. It is found that the collective oblate rotation coexists with the high-K prolate rotation. Superdeformed prolate rotation is included in this calculation.

关键词： nuclear shape oblate rotation prolate rotation

Long time behavior for damped generalized coupled nonlinear wave equations. Ⅱ.Unbounded domain

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Communications in Nonlinear Science and Numerical Simulation 2001年第2期6卷 107-110页

作者： Shaomei FANG and Boling GUO Department of Mathematics, Shaoguan University, Shaoguan 512.05, china Graduate School, china Academy of Engineering {2., {3. 100088, china center for Nonlinear Studies, institute of Applied {2. and Computational Department of Mathematics Shaoguan University Shaoguan 512005 China Graduate School China Academy of Engineering Physics Beijing 100088 China center for Nonlinear Studies Institute of Applied Physics and Computational mathematics Beijing 100088 China

In this paper, by using a priori estimates in the weighted space, the existence of the global attractor for the damped generalized coupled nonlinear wave equations in an unbounded domain is obtained.

关键词： unbounded domain weighted space attractor

Semi-analytical analysis of the response of the air temperature over the land surface to the global vegetation distribution

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Chinese Science Bulletin 2009年第14期54卷 2499-2505页

作者： LIU Fei1,2.& CHAO JiPing3.4 1 institute of Atmospheric physics, Chinese Academy of Sciences, {2. 10002., china 2.Graduate University of Chinese Academy of Sciences, {2. 100049, china 3.National Marine Environmental Forecasting center, {2. 100081, china 4 First institute of Oceanography, State Oceanic Administration of china, Qingdao 2.6061, china institute of Atmospheric physics Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China National Marine Environmental Forecasting center Beijing China First institute of Oceanography State Oceanic Administration of China Qingdao China

Response of the air temperature over the land surface to the global vegetation distribution is investigated, using a three-dimensional governing equation to simulate the steady, large-scale, limited amplitude perturbation of the free, inviscid and adiabatic atmosphere. The adoption of the static equation leads to a temperature governing equation in the terrain following coordinate. With the prescribed temperature as the upper boundary condition and the radiation balance as the lower boundary condition, the semi-analytical solution of the global circulation temperature can be calculated. In this article, only the air temperature (at 2.m height) over the land surface is analyzed, and the result suggests that this model can simulate the air temperature pattern over the land surface reasonably. A better simulation occurs when a simple feedback of the albedo on the temperature is included. Two sensitivity experiments are analyzed through this model. One suggests that the air temperature over the land surface descends obviously when the land surface is covered with ice all over, while another suggests that the air temperature rises a little when the land surface is covered with forest except the ice-covered area. This model appears to be a good tool to study the response of the air temperature to the vegetation distribution. Limitations of the model are also discussed.

关键词：空气温度植被分布陆地表面反应解析分析模拟模式控制方程边界条件

MOLECULAR SIMULATION STUDY ON THE CHANGE OF POLYMER STRUCTURE DURING YIELDING

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Chinese Journal of Polymer Science 2001年第5期19卷 527-529页

作者： Chen-guang Xu Tai-ning Liang Juan Sun Xiao-zhen Yang State Key Laboratory of Polymer physics and Chemistry center for Molecular Science, {2. of Chemistry Chinese Academy of Sciences,{3. china 中科院化学所高分子物理与化学国家重点实验室北京

A better understanding of a recently raised argument on whether there occurs a structure change during yielding has been acquired by using molecular simulation. That is, when monitoring the displacements of all atoms before and after the yield, a structure transition does occur, which is the 'atomic jump' that coordinates the amount of the atoms in the polymer and makes a large step beyond similar to0.05 nm for all those atoms. Results indicate that the complex of polymer chain packing induces the multiple atomic jumps around the yield point. This explains why polymers have a broader yielding peak.

关键词： polymer deformation yield structure transition atomic jump multiple yields

Latest cosmological constraints on Cardassian expansion models including the updated gamma-ray bursts

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Research in Astronomy and Astrophysics 2011年第9期11卷 1019-1030页

作者： Nan Liang Pu-Xun Wu Zong-Hong Zhu Department of Astronomy Beijing Normal University Beijing 100875 China center for High Energy physics Peking University Beijing 100871 China center of Nonlinear Science and Department of physics Ningbo University Ningbo 315211 China

We constrain the Cardassian expansion models from the latest observa- tions, including the updated Gamma-ray bursts （GRBs）, which are calibrated using a cosmology independent method from the Union2.compilation of type Ia supernovae （SNe Ia）. By combining the GRB data with the joint observations from the Union2.SNe Ia set, along with the results from the Cosmic Microwave Background radia- tion observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release. we find significant constraints on the model oarameters of the original Cardassian model ΩM0=0.2.2.0.014^0.015,n=0.03.0.05^＋0.05 and n=-0.16-3.2.^＋0.2.,β=0.76-0.58^＋0.3. of the modified polytropic Cardassian model, which are consistent with the ACDM model in a l-or confidence region. From the reconstruction of the deceleration parameter q（z） in Cardassian models, we obtain the transition redshift ZT = 0.73.± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.

关键词： gamma-rays bursts -- cosmology cosmological parameters

Refraction of light in media

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Science china(physics,Mechanics & Astronomy) 2007年第5期50卷 591-600页

作者： ZHANG Tao Key Laboratory of Beam Technology and Material Modification of Ministry of Education, institute of Low Energy Nuclear physics, {2. Normal University, {2. 100875, china {2. Radiation center, {2. 100875, china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation center Beijing China

The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium. The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s Law is applied to this conductor that is in the alternating magnetic field of the light. dBM/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy, i.e. the refractive energy, with the elec- tron cloud conductor. Formulas of refractive index, which is the ratio of light speed in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.

关键词： refractive index, light, speed, medium, propagation

Anomalous boundary deformation induced by enclosed active particles

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Chinese physics B 2017年第10期26卷 82-88页

作者：田文得顾燕郭永坤陈康 center for Soft condensed {2.{3. & Interdisciplinary Research College of Physics Optoelectronics and EnergySoochow University Kavli institute for Theoretical physics{2. Chinese Academy of Sciences

We simulate a two-dimensional model of a round soft boundary enclosed with self-propelled particles. Persistent motion drives these particles to accumulate near the boundary, thereby dramatically deforming the boundary shape through collisions. Quantitative analyses of the boundary shape and the particle distribution show that there are two typical regimes in the variation of the morphology with the increase of self-propulsion of particles. One is under small forces, characterized by the radially inhomogeneous distribution of particles and the suppression of local fluctuations of the almost round boundary, and the other is under large forces, featured by the angularly inhomogeneous distribution of particles and the global shape deformation of the boundary. These two features are strongly cooperative. We also find different mechanisms in the particle relocation at low and high particle concentrations.

关键词： self-propelled particles boundary active matter confinement

THE LIGHT INDUCED CHANGE IN TRANSIENT PHOTOCONDUC-TIVITY OF POLYMORPHOUS SILICON FILMS

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 453-456页

作者： S.B. Zhang, G.L. Kong, Y. Y. Xu, Y.Q. Wang, H.W. Diao and X.B. Liao (State Laboratory for Surface physics, institute of Semiconductors & {2. for{3. matter physics, Chinese Academy of Sciences, beijing 100083. china) Inst. of Semiconduct. Chinese Acad. of Sci. Beijing 100083 China

The decays of transient photoconductivity and their light-induced changes of polymorphous silicon (pm-Si:H) films were investigated. The decays can be fit fairly well by a sum of two exponential decay functions, which indicates that there are two kinds of traps contributing to the process. The light-induced changes of the concentration and energy level of the traps were estimated. The results show that the light-induced changes in trap energy position Et, trap concentration Nt as well as photoconductivity are markedly less for pm-Si:H than that for a-Si:H.

关键词： light-induced change transient film