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Nonextensive and extensive thermostatistic properties of Fermi systems trapped in different external potentials 被引量:3
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作者 黄志福 欧聪杰 陈金灿 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1380-1388,共9页
The thermostatistic properties of a q-generalized Fermi system trapped in a generic power-law potential are studied, based on the generalized statistic distribution derived from the Tsallis entropy. The total number o... The thermostatistic properties of a q-generalized Fermi system trapped in a generic power-law potential are studied, based on the generalized statistic distribution derived from the Tsallis entropy. The total number of particles, the total energy, and the heat capacity at constant volume of the system are derived. The thermostatistic characteristics of the system are discussed in detail. It is found that the thermostatistic properties of such a system depend closely on parameter q, dimensional number of the space, kinetic characteristics of particles and shapes of the external potential, and the external potential has a great influence on the thermostatistie properties of the system. Moreover, it is shown that the results obtained here are very general and can be used to unify the description of the nonextensive and extensive thermostatistie properties of a class of Fermi systems trapped in different external potentials so that the important conclusions of many typical Fermi systems in the literature may be directly derived from the present paper. 展开更多
关键词 generalized Fermi system external potential thermostatistic property
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Control of soliton characteristics of the condensate by an arbitrary x-dependent external potential 被引量:1
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作者 杨如曙 姚春梅 陈日新 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期3736-3741,共6页
This paper presents a family of soliton solutions of the one-dimensional nonlinear Schrodinger equation which describes the dynamics of the dark solitons in Bose-Einstein condensates with an arbitrary x-dependent exte... This paper presents a family of soliton solutions of the one-dimensional nonlinear Schrodinger equation which describes the dynamics of the dark solitons in Bose-Einstein condensates with an arbitrary x-dependent external potential. The obtained results show that the external potential has an important effect on the dark soliton dynamical characteristics of the condensates. The amplitude, width, and velocity of the output soliton are relative to the source position of the external potential. The smaller the amplitude of the soliton is, the narrower its width is, and the slower the soiiton propagates. The collision of two dark solitons is nearly elastic . 展开更多
关键词 Bose Einstein condensates dark solitons x-dependent external potential
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Effect of Spatial Dimension and External Potential on Joule-Thomson Coefficients of Ideal Bose Gases
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作者 袁都奇 王参军 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第4期669-672,共4页
Based on the form of the n-dimensional generic power-law potential, the state equation and the heat capacity, the analytical expressions of the Joule-Thomson coefficient (3TC) for an ideal Bose gas are derived in n-... Based on the form of the n-dimensional generic power-law potential, the state equation and the heat capacity, the analytical expressions of the Joule-Thomson coefficient (3TC) for an ideal Bose gas are derived in n-dimensional potential. The effect of the spatial dimension and the external potential on the JTC are discussed, respectively. These results show that: (i) For the free ideal Bose gas, when n/s ≤ 2 (n is the spatial dimension, s is the momentum index in the relation between the energy and the momentum), and T → Tc (Tc is the critical temperature), the JTC can obviously improve by means of changing the throttle valve's shape and decreasing the spatial dimension of gases. (ii) For the inhomogeneous external potential, the discriminant △= [1 - y∏^ni=1(kT/εi)^1/tiГ(1/ti+1)] (k is the Boltzmann Constant, T is the thermodynamic temperature, ε is the external field's energy), is obtained. The potential makes the JTC increase when △ 〉 0, on the contrary, it makes the JTC decrease when A 〈△. (iii) In the homogenous strong external potential, the JTC gets the maximum on the condition of kTεi〈〈1. 展开更多
关键词 ideal Bose gases Joule-Thomson coefficient spatial dimension external potential field
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Controlling Soliton Collisions of Condensates by Time-Dependence of Both Interactions and External Potential
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作者 何章明 王登龙 +1 位作者 丁建文 颜晓红 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第5期795-800,共6页
Considering time-dependence of both interactions and external potential,we analytically study the collisional behaviors of two bright solitons in Bose-Einstein condensates by using Darboux transformation.It is found t... Considering time-dependence of both interactions and external potential,we analytically study the collisional behaviors of two bright solitons in Bose-Einstein condensates by using Darboux transformation.It is found that for a closed external potential,the soliton-soliton distance is decreased with nonlinearly increased interactions,while the amplitude of each soliton increases and its width decreases.For linearly increased interactions but nonlinearly decreased external potential,especially,the atom transfer between two solitons is observed,different from previous theory of no atom transfer in solitons collision in a fixed external potential.In addition,it is shown that the collisional type,such as head-on,"chase",or collision period between two solitons,can be controlled by tuning both interactions and external potential.The predicted phenomena can be observed under the condition of the current experiments and open possibilities for future application in atoms transport. 展开更多
关键词 Bose-Einstein condensates bright solitons time-dependent interactions time-dependent external potential
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Molecular properties and potential energy function model of BH under external electric field 被引量:7
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作者 伍冬兰 谭彬 +2 位作者 万慧军 张新琴 谢安东 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第12期194-198,共5页
Using the density functional B3P86/cc-PV5Z method, the geometric structure of BH molecule under different external electric fields is optimized, and the bond lengths, dipole moments, vibration frequencies, and other p... Using the density functional B3P86/cc-PV5Z method, the geometric structure of BH molecule under different external electric fields is optimized, and the bond lengths, dipole moments, vibration frequencies, and other physical properties parameters are obtained. On the basis of setting appropriate parameters, scanning single point energies are obtained by the same method and the potential energy curves under different external fields are also obtained. These results show that the physical property parameters and potential energy curves may change with external electric field, especially in the case of reverse direction electric field. The potential energy function without external electric field is fitted by Morse potential, and the fitting parameters are obtained which are in good agreement with experimental values. In order to obtain the critical dissociation electric parameter, the dipole approximation is adopted to construct a potential model fitting the corresponding potential energy curve of the external electric field. It is found that the fitted critical dissociation electric parameter is consistent with numerical calculation, so that the constructed model is reliable and accurate. These results will provide important theoretical and experimental reference for further studying the molecular spectrum, dynamics, and molecular cooling with Stark effect. 展开更多
关键词 BH molecule potential function model external electric field
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The Analytical Potential Energy Function of NH Radical Molecule in External Electric Field 被引量:5
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作者 伍冬兰 谭彬 +2 位作者 万慧军 谢安东 丁大军 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期34-37,共4页
The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR s... The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect. 展开更多
关键词 The Analytical potential Energy Function of NH Radical Molecule in external Electric Field NH
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Collective transport of Lennard-Jones particles through one-dimensional periodic potentials
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作者 何健辉 温家乐 +2 位作者 陈沛荣 郑冬琴 钟伟荣 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第7期7-14,共8页
The surrounding media in which transport occurs contains various kinds of fields, such as particle potentials and external potentials. One of the important questions is how elements work and how position and momentum ... The surrounding media in which transport occurs contains various kinds of fields, such as particle potentials and external potentials. One of the important questions is how elements work and how position and momentum are redistributed in the diffusion under these conditions. For enriching Fick's law, ordinary non-equilibrium statistical physics can be used to understand the complex process. This study attempts to discuss particle transport in the one-dimensional channel under external potential fields. Two kinds of potentials—the potential well and barrier—which do not change the potential in total, are built during the diffusion process. There are quite distinct phenomena because of the different one-dimensional periodic potentials. By the combination of a Monte Carlo method and molecular dynamics, we meticulously explore why an external potential field impacts transport by the subsection and statistical method. Besides, one piece of evidence of the Maxwell velocity distribution is confirmed under the assumption of local equilibrium. The simple model is based on the key concept that relates the flux to sectional statistics of position and momentum and could be referenced in similar transport problems. 展开更多
关键词 TRANSPORT external potential collective diffusion Maxwell velocity distribution
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