检索结果-南通市图书馆

From the Green's Function in Tight-Binding Representation to Interatomic Many-body Potentials

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第4期15卷 315-319页

作者： Shaojun LIU(department of physics, Beijing normal university, Beijing 100875, China)Xiaobo WEI(department of physics, Liuzhou College of Education, Liuzhou 545005, China)Zhaodou CHEN Jun CAI and Benkun MA(department of physics, Beijing normal university, department of physics Beijing Normal University Beijing 100875 China department of physics Liuzhou College of Education Liuzhou 545005 China

In this paper, we deduce the analytical form of many-body interatomic potentials based on the Green's function in tight-binding representation. The many-body potentials are expressed as the functions of the hopping integrals which are the physical origin of cohesion of atoms. For thesimple case of s-valent system, the inversion of the many-body potentials are discussed in detail by using the lattice inversion method.

关键词： Rev Li Chen From the Green’s Function in Tight-Binding Representation to Interatomic Many-body Potentials body

Constraints of f(R) gravity in Palatini approach with observational Hubble data

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2011年第8期54卷 1378-1383页

作者： ZHAI ZhongXu & LIU WenBiao department of physics, Institute of Theoretical physics, Beijing normal university, Beijing 100875, China Beijing normal university Department of Physics Institute of Theoretical Physics Beijing China (GRID:grid.20513.35) (ISNI:***)

We use the newly released observational H(z) data (OHD), the Cosmic Microwave Background (CMB) shift parameter, and the Baryon Acoustic Oscillation (BAO) measurements data to constrain cosmological parameters of f(R) gravity in Palatini formalism in which the f(R) form is defined as f(R) = R β/Rn. Under the assumption of a spatially flat FRW universe, we get the best fitting results of the free parameters (Ωm0, n). In the calculation, we marginalize the likelihood function over H0 by integrating the probability density P ∝ e-χ2/2 to obtain the best fitting results and the confidence regions in the Ωm0-n plane. The constraints results of (Ωm0, n) = (0.33, 0.41) by OHD only and (Ωm0, n) = (0.23, 0.08) by the combination of OHD+CMB+BAO both indicate that the universe goes through three last phases, i.e., radiation dominated, matter-dominated, and late time accelerated expansion without introduction of dark energy.

关键词： f(R) gravity OHD CMB BAO accelerating expansion dark energy

D-Dimensional Dirac Fermions BEC-BCS Crossover Thermodynamics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2007年第7期48卷 99-106页

作者： CHEN Ji-Sheng Institute of Particle physics & physics department,Central China normal university,Wuhan 430079,China Institute of Particle physics Central China Normal University physics department Central China Normal University

An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions *** interior quantumfluctuation effects are incorporated as an external field approximation indirectly through a fictive generalized ThomsonProblem counterterm *** general analytical formulas for the d-dimensional thermodynamics are given nearthe unitary limit region,In the non-relativistic limit for d=3,the universal dimensionless coefficientε=4/9 andenergy gap △/ε_f=5/18 are reasonably consistent with the existing theoretical and experimental *** the unitarylimit for d=2 and T=0,the universal coefficient can even approach the extreme occasion ξ=0 corresponding to theinfinite effective fermion mass m~*=∞,which can be mapped to the strongly coupled two-dimensional electrons and isquite similar to the three-dimensional Bose-Einstein condensation of ideal boson ***,for d=1,the universalcoefficient ξ is negative,implying the non-existence of phase transition from superfluidity to normal *** solutionsmanifest the quantum Ising universal class characteristic of the strongly coupled unitary fermions gas.

关键词： unitary fermions thermodynamics BEC-BCS crossover statistical methods

Output Rate of Atomic Four-Wave Mixing in Two-Component Bose-Einstein Condensate

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2004年第5期41卷 695-698页

作者： LI Jia-Hua~1 LI Wei-Bing~1 PENG Ju-Cun~2 1 department of physics,huazhong university of Science and Technology,Wuhan 430074,China2 department of physics,Xiaogan normal university,Xiaogan 432100,China department of physics Huazhong University of Science and Technology Wuhan 430074 China department of physics Xiaogan Normal University Xiaogan 432100 China

In this letter,following the proposal of Heurich et al.[***.A63(2001)033605],we analyze anddiscuss output rate of atomic four-wave mixing in the two-component Bose-Einstein condensate under the condition ofthe steady *** results show that the magnitude of the signal beam increases with the increase of the intensityof the probe beam,up to a saturated value,then it decreases as the probe beam *** influence of theinteraction range on the signal beam is also *** particular,it is worth while pointing out that in contrast tothe previous solutions,our obtained analytical solutions are of very simple and explicit forms,which open the door forfurther investigating the related physical mechanisms.

关键词： atomic four-wave mixing steady state Bose-Einstein condensate

Analytic Solution of the Three-Variable Dynamical Equations of Oscillation Phenomena in B-Z Reaction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese universities 2001年第3期17卷 311-314页

作者： LU Ling (department of physics, Liaoning normal university, Dalian 116029, P. R. China) department of physics Liaoning Normal University Dalian 116029 China

The dynamical behaviour of the inorganic bromate oscillator catalyzed by manganese ions in the B-Z reaction is discussed, a three-variable nonlinear dynamical equations of the oscillation phenomena have been obtained,... 详细信息

关键词： B-Z reaction Oscillation Analytic solution

Lookback time as a test for f(R) gravity in the Palatini approach

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第11期11卷 1257-1265页

作者： Zhong-Xu Zhai and Wen-Biao Liu department of physics, Institute of Theoretical physics, Beijing normal university, Beijing 100875, China department of physics Institute of Theoretical Physics Beijing Normal University

We use the recently released data of lookback time (LT)-redshift relation, the cosmic microwave background shift parameter and the baryon acoustic oscillation measurements to constrain cosmological parameters of f (R) gravity in the Palatini formalism by considering the f (R) form of type (a) f (R) = R β/Rn and (b) f (R) = R + α ln R β. Under the assumption of a Friedmann-Robertson-Walker universe, we achieved the best fitting results of the free parameters (Ωm0, n) for (a) and (Ωm0, α) for (b). We find that current LT data can provide interesting and effective constraints on gravity models. Compared with other data, the LT constraints favor a smaller value of the non-relativistic matter energy density.

关键词： cosmology cosmic microwave background

Absorption Cross Section of Einstein-Maxwell Dilation Axion Black Hole for Dirac Particles

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2007年第12期48卷 1051-1054页

作者： LIU Chang-Qing JING Ji-Liang Institute of physics and department of physics,Hunan normal university,Changsha 410081,China Institute of physics and department of physics Hunan Normal University

The absorption cross section of the Einstein-Maxwell Dilaton Axion (EMDA) black hole for Dirac particlesis *** is shown that the absorption cross section decreases as both the v and the absolute value of the dilatonincrease,but it increases as the mass of the particle *** is also shown that the absorption cross section for themassless Dirac particles is 1/8 of the area of the horizon,which may be an universal property for minimally coupledmassless Dirac particles.

关键词： black hole absorption cross section Dirac particle

The Ambient Gas Effects on Pulsed Laser Ablation of Target

在线全文

学校读者我要写书评

暂无评论

光电子·激光 1996年第1期7卷 12-15页

作者： Gongtang Wang Xiangtai Wang Baoyuan Mian(department of physics,Shandong normal university,Jinan 250014)Bingzhang Xu Liangmo Mei(department of physics.Shandong university,Jinan 250100) 山东师范大学物理系山东济南山东大学物理系山东济南

ＴｈｅＡｍｂｉｅｎｔＧａｓＥｆｆｅｃｔｓｏｎＰｕｌｓｅｄＬａｓｅｒＡｂｌａｔｉｏｎｏｆＴａｒｇｅｔ￥ＧｏｎｇｔａｎｇＷａｎｇ；ＸｉａｎｇｔａｉＷａｎｇ；ＢａｏｙｕａｎＭｉａｎ（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，... 详细信息

ＴｈｅＡｍｂｉｅｎｔＧａｓＥｆｆｅｃｔｓｏｎＰｕｌｓｅｄＬａｓｅｒＡｂｌａｔｉｏｎｏｆＴａｒｇｅｔ￥ＧｏｎｇｔａｎｇＷａｎｇ；ＸｉａｎｇｔａｉＷａｎｇ；ＢａｏｙｕａｎＭｉａｎ（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，ＳｈａｎｄｏｎｇＮｏｒｍａｌＵｎｉ...

关键词： Al￣+ ion mean projected range laser ablation ambient gas effect.

The information entropy of a static dilaton black hole

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2008年第2期51卷 113-125页

作者： LIU ChengZhou Institute of Theoretical physics, Binzhou university, Binzhou 256600, China department of physics, Beijing normal university, Beijing 100875, China Institute of Theoretical physics Binzhou University Binzhou China department of physics Beijing Normal University Beijing China

In accordance with holographic principle, by calculating the statistical entropy of the quantum field just at the event horizon of the Garfinkle-Horowitz-Strominger dilaton black hole, the information entropy of the black hole was investigated and the Bekenstein-Hawking formula was obtained. The results show that black hole entropy is identical with the statistical entropy of the quantum field at the horizon. Using the generalized uncertainty relation, the divergence of the state density near the event horizon in usual quantum field theory was removed, and the cutoffs and the little mass approximation in the heat gas method of black hole entropy were avoided. Thus, the microstates of the massive scalar field just at the event horizon of the static dilaton black hole were studied directly and a description on holograph principle was presented. By using residue theorem, the integral difficulty in the calculation was overcome, and the information entropy and the Bekenstein-Hawking formula were obtained quantitatively. Compared with the black hole entropy from the loop quantum gravity, the consistency of methods and results of calculating black hole entropy in non-commutative quantum field theory and loop quantum gravity was investigated. By this, the gravity correction constant in the generalized uncertainty relation was suggested and the sense of holographic principle was discussed.

关键词： black hole entropy holographic principle non-commutative quantum field theory event horizon loop quantum gravity