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41.
We find the existence of a quantum thermal effect, “Hawking absorption.” near the inner horizon of the Kerr–Newman black hole. Redefining the entropy, temperature, angular velocity, and electric potential of the black hole, we give a new formulation of the Bekenstein–Smarr formula. The redefined entropy vanishes for absolute zero temperature of the black hole and hence it is interpreted as the Planck absolute entropy of the KN black hole.  相似文献   
42.
A new class of distributions for the microcanonical ensemble, which are shown to be stable laws, are derived by applying the central limit theorem to the canonical ensemble. This opens up a whole new host of phenomena that can be treated from a unified thermodynamic point of view. Pressure broadening of line shapes is used as an illustration.1. Work supported, in part, by contributions from the Consiglio Nazionale di Ricerche and the Ministero dell'Università e della Ricerca Scientifica e Tecnologica.2. The interaction parameterC is proportional to the mean square dipole moment. As an order of magnitude of the dipole moment, we can take it as the product of the electric charge and a typical atomic radius for a moderately excited state, which is several times the Bohr radius. Multiplication by the fine structure constant converts the Bohr radius into the Compton wavelength, thereby reducing the magnitude of the interaction by 1/137.  相似文献   
43.
44.
Boron-nitride (BN) domains in graphene or graphene domains in BN monolayer offer additional freedoms for tuning the electronic properties of these BN/C nanostructures, which is quite crucial for the applications in nanoscale devices. Based on first-principles calculations combined with a simple Hubbard model, we show that the electron zero-energy states (ZESs) of BN/graphene core–shell quantum dots (QDs) in triangular shapes can be well tuned by varying the size and topology of each domain. The net spin of the systems is dominated by the graphene segment which can be described by a Lieb?s theorem. We also demonstrated that a π-electron Hubbard model within a mean-field approximation is implementable in dealing with the electron spin-polarization of BN/C hetero-structured graphene-like materials. This provides an efficient theoretical approach for the BN/C systems where electron spin-polarization is involved.  相似文献   
45.
Two random-walk related problems which have been studied independently in the past, the expected maximum of a random walker in one dimension and the flux to a spherical trap of particles undergoing discrete jumps in three dimensions, are shown to be closely related to each other and are studied using a unified approach as a solution to a Wiener-Hopf problem. For the flux problem, this work shows that a constant c = 0.29795219 which appeared in the context of the boundary extrapolation length, and was previously found only numerically, can be derived analytically. The same constant enters in higher-order corrections to the expected-maximum asymptotics. As a byproduct, we also prove a new universal result in the context of the flux problem which is an analogue of the Sparre Andersen theorem proved in the context of the random walker's maximum.  相似文献   
46.
曾谨言 《大学物理》2002,21(7):23-28
介绍了量子绝热定理的物理含义及成立的条件,认为有关主要献(Aharonov-Anandan,Bohm,孙昌璞等)的表述是正确的,而《关于量子几何相位的评注》^[1](以下简称《评注》)相应的表述不完全正确。在此基础上,认为这些献和教材(R.Shankar)得出的涉及Berry绝热相位的一些论述(不含Berry绝热相因子的瞬时能量本征态不满足含时Schroedinger方程等)也是正确的,而《评注》的论述与此相反。《评注》认为只有γn(C)才是Berry相位。本作则倾向于把γn(t)叫做Berry绝热相位,而把γn(C)=γn(T)-γn(0)叫做几何相位(geometric phase)^[2]。  相似文献   
47.
完整有势力学系统的高阶Lagrange方程   总被引:11,自引:0,他引:11       下载免费PDF全文
张相武 《物理学报》2005,54(10):4483-4487
首先提出力学系统高阶速度能定理,阐明了系统高阶速度能量的物理意义;然后提出力学系统有势的一般判据.在此基础上,引入高阶Lagrange函数,得出完整有势力学系统的高阶Lagrange方程,并得到系统高阶循环积分和高阶广义能量积分. 关键词: 高阶速度能定理 有势力学系统 高阶Lagrange方程 高阶Lagrange函数  相似文献   
48.
McKean-Vlasov limit for interacting random processes in random media   总被引:2,自引:0,他引:2  
We apply large-deviation theory to particle systems with a random mean-field interaction in the McKean-Vlasov limit. In particular, we describe large deviations and normal fluctuations around the McKean-Vlasov equation. Due to the randomness in the interaction, the McKean-Vlasov equation is a collection of coupled PDEs indexed by the state space of the single components in the medium. As a result, the study of its solution and of the finite-size fluctuation around this solution requires some new ingredient as compared to existing techniques for nonrandom interaction.  相似文献   
49.
对于球解高对称性静磁场,如果仅应用安培环路定理和高斯定理,在解答中会存在一些不能唯一确定的常量,为了研究确定这些常量的规律,本讨论了穿过一个无限大平面的磁通量并用得到了一个有意义的结论。  相似文献   
50.
Correlation functions of a driven two‐level system embedded in a photonic crystal are analyzed. The spectral density of the photonic bands near a gap makes this system non‐Markovian. The equations of motion for two‐time correlations are derived by two different methods, the quantum regression theorem and the fluctuation dissipation theorem, and found to be the same.  相似文献   
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