检索结果-南通市图书馆

Radiation spectrum of a high-dimensional rotating black hole

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第3期53卷 504-507页

作者： ZHAO Ren, LI HuaiFan, ZHANG LiChun & WU YueQin Institute of Theoretical physics, shanxi datong university department of physics, shanxi datong university, datong 037009, china 1. Institute of Theoretical physics Shanxi Datong University Datong 037009 China

This study extends the classical Damour-Ruffini method and discusses Hawking radiation in a (n + 4)-dimensional rotating black hole. Under the condition that the total energy and angular momentum of spacetime are conservative, but angular momentum a = J/M of unit mass of the black hole is variable, taking into consideration the reaction of the radiation of the particle to the spacetime, a new Tortoise coordinate transformation and discuss the black hole radiation spectrum is discussed. The radiation spectrum that satisfies the unitary principle in the general case is derived.

关键词： Damour-Ruffini method Hawking radiation Tortoise coordinate transformation high-dimensional rotating spacetime

Tests for nonparametric parts on partially linear single index models

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2007年第3期50卷 439-449页

作者： Ri-quan ZHANG department of Statistics, East china Normal university, Shanghai 200062, china department of Mathematics, shanxi datong university, datong 037009, china department of Statistics East China Normal University Shanghai 200062China

Tests for nonparametric parts on partially linear single index models are considered in this paper. Based on the estimates obtained by the local linear method, the generalized likelihood ratio tests for the models are established. Under the null hypotheses the normalized tests follow asymptotically the χ2-distribution with the scale constants and the degrees of freedom being independent of the nuisance parameters, which is called the Wilks phenomenon. A simulated example is used to evaluate the performances of the testing procedures empirically.

关键词： local linear method partially linear single index models generalized likelihood ratio test Wilks phenomenon χ 2-distribution 62G10 62G20

Spin-dependent thermoelectric transport through double quantum dots

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2012年第11期21卷 432-440页

作者：王强解海卿焦虎军李志坚聂一行 Institute of Theoretical physics and department of physics Shanxi University Institute of Solid State physics Shanxi Datong University

We study the thermoelectric transport through a double-quantum-dot system with spin-dependent interdot cou- pling and ferromagnetic electrodes by means of the non-equilibrium Green＇s function in the linear response regime. It is found that the thermoelectric coefficients are strongly dependent on the splitting of the interdot coupling, the relative magnetic configurations, and the spin polarization of leads. In particular, the thermoelectric efficiency can reach a considerable value in the parallel configuration when the effective interdot coupling and the tunnel coupling between the quantum dots and the leads for the spin-down electrons are small. Moreover, the thermoelectric efficiency increases with the intradot Coulomb interaction increasing and can reach very high values at appropriate temperatures. In the presence of the magnetic field, the spin accumulation in the leads strongly suppresses the thermoelectric efficiency, and a pure spin thermopower can be obtained.

关键词： thermoelectric effect double quantum dots spin effect

Effects of Chuanxiongqin hydrochloride on increasing the fluidity of brain cell membrane and scavenging free radicals in model rats with ischemia/reperfusion injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第8期1卷 721-724页

作者： Chenxu Li Institute of Brain Sciences department of Physiology, Medical College, datong university, datong 037008, shanxi Province, china Institute of Barin Sciences Department of Physiology Datong University Datong 037008 Shanxi Province China

BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; department of Physiology, Medical College, datong university. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking university from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared betwe

关键词： Effects of Chuanxiongqin hydrochloride on increasing the fluidity of brain cell membrane and scavenging free radicals in model rats with ischemia/reperfusion injury cell free

Synthesis　of　an　N^5N^（10）－methenyltetrahydrofolate　Model　and　Its　Substituted　One－Carbon　Unit　Transfer　Reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第9期7卷 803-806页

作者： Jian Xin CHEN Chi Zhong XIA and Jin Pei CHENG(datong Medical College,datong,shanxi,037008)(department of Chemistry,shanxi university,Taiyuan, 030006.)(Nankai university,Tianjin,300071) datong Medical College Datong Shanxi 037008 department of Chemistry Shanxi University Taiyuan 030006 Nankai university Tianjin 300071

Substituted imidazolinium salt,1,2-dimethyl-3-(p-methoxybenzenesulfonyl) imidazolinium iodide,as a tetrahydrofolate model in terms of the ability to transfer a substituted one-carbon unit (ethylidyne,nitromethylethylidene),can react with a variety of mono-and bifunctional nucleophiles and lead to some carboline alkaloids and other heterocyclic compounds.

关键词： Synthesis an N~5N Its Carbon

Rearrangement of Hydrolysis Products of Tetrahydrofolate model compound

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第9期10卷 727-728页

作者： Jian Xin CHENI Jun Sheng HAO Wei GUO Chi Zhong XIA(1datong Medical College,datong,shanxi 0370082department of Chemistry. shanxi university, Taiyuan 030006) datong Med Coll Datong 037008 Shanxi Peoples R China shanxi Univ Dept Chem Taiyuan 030006 Peoples R China

The hydrolysis products of tetrahydrofolate model compound 4 were a mixture of 6 and 7 and the rearrangement reaction between 6 and 7 via 5 was in a state of equilibrium, confirmed by (HNMR)-H-1 and IR spectra.

关键词： tetrahydrofolate hydrolysis rearrangement

Minimal Rank Preserving Additive Mappings on Upper Triangular Matrices

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research and Exposition 2011年第6期31卷 951-964页

作者： Yu GUO1,2,3,Jin Chuan HOU2,3 1.department of Mathematics,shanxi datong university,shanxi 037009,P.R.china 2.department of Mathematics,shanxi university,shanxi 030006,P.R.china 3.department of Mathematics,Taiyuan university of Technology,shanxi 030024,P.R.china department of Mathematics Shanxi Datong University department of Mathematics Shanxi University department of Mathematics Taiyuan University of Technology

The additive mappings that preserve the minimal rank on the algebra of all n × n upper triangular matrices over a field of characteristic 0 are characterized.

关键词： rank minimal rank upper triangular matrices additive mappings

Particle tunnels across the horizon of Garfinkle-Horowitz-Strominger dilaton black hole

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2007年第5期50卷 601-610页

作者： FANG HengZhong1 & ZHAO Zheng2 1 department of physics, china university of Petroleum, Dongying 257061, china 2 department of physics, Beijing Normal university, Beijing 100875, china department of physics China University of Petroleum Dongying 257061 China department of physics Beijing Normal University Beijing 100875 China

We promote the work of Parikh and Wilczek on the black hole radiation to the emission of massive and charged particles from Garfinkle-Horowitz-Strominger black hole. The energy and charge of the space-time are conservational during the course of the evaporation. The calculation shows that the emission spectrum is not precisely thermal, while has a correction, and the conclusion supports the view- point of information conservation.

关键词： Hawking radiation, black body spectrum, barrier, information loss, entropy of black hole, Komar energy

Density-functional formula for strongly correlated systems

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2 and CHEN Nanxian1(1. department of physics, Tsinghua university, Beijing 100084, china 2. department of physics, Peking university, Beijing 100871, china) department of physics Tsinghua University Beijing 100084 China department of physics Peking University Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.