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β-Ga_(2)O_(3)热电性能的第一性原理计算

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原子与分子物理学报 2025年第1期42卷 180-188页

作者：邓南发周贤中广东工业大学集成电路学院广州510006

通过使用第一性原理计算方法和玻尔兹曼输运理论,计算了β-Ga_(2)O_(3)的电学、热学和热电性质,并得出了热电性能因子随载流子浓度和温度的变化规律.此外,还考虑了声子散射和极性光学声子散射对平均电子弛豫时间的影响,并详细描述了不... 详细信息

通过使用第一性原理计算方法和玻尔兹曼输运理论,计算了β-Ga_(2)O_(3)的电学、热学和热电性质,并得出了热电性能因子随载流子浓度和温度的变化规律.此外,还考虑了声子散射和极性光学声子散射对平均电子弛豫时间的影响,并详细描述了不同载流子浓度和温度下β-Ga_(2)O_(3)的Seebeck系数、电导率、电热导率和功率因数的计算结果.最后,给出了β-Ga_(2)O_(3)的热电性能因子随载流子浓度和温度的变化趋势.结果表明,在高载流子浓度和高温下,β-Ga_(2)O_(3)具有较高的热电性能因子.

关键词： Ga_(2)O_(3) 第一性原理计算波尔兹曼输运理论热电性质

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LONG-TIME BEHAVIOR OF FINITE DIFFERENCE SOLUTIONS OF THREE-DIMENSIONAL NONLINEAR SCHRODINGER EQUATION WITH WEAKLY DAMPED

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Journal of Computational Mathematics 2004年第4期22卷 593-604页

作者： fa-yongZhang DepartmentofMathematics HeilongjiangUniversityHarbin150080China

The three-dimensional nonlinear SchrSdinger equation with weakly damped that possesses a global attractor are considered. The dynamical properties of the discrete dynamical system which generate by a class of finite d... 详细信息

关键词： Nonlinear Schrodinger equation Finite difference method Global attractor

Algebraic Conditions for Classifying the Positional Relationships Between TwoConies and Their Applications

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Journal of Computer Science & Technology 2004年第5期19卷 665-673页

作者： YangLiu fa-LaiChen DepartmentofComputerScience TheUniversityofHongKongHongKongSpecialAdministrativeRegionP.R.China DepartmentofMathematics UniversityofScienceandTechnologyofChinaHefei230026P.R.China

In many fields of computer science such as computer animation, computergraphics, computer aided geometric design and robotics, it is a common problem to detect thepositional relationships of several entities. Based on generalized characteristic polynomials andprojective transformations, algebraic conditions are derived for detecting the various positionalrelationships between two planar conies, namely, outer separation, exterior contact, intersection,interior contact and inclusion. Then the results are applied to detecting the positionalrelationships between a cylinder (or a cone) and a quadric. The criteria is very effective andeasier to use than other known methods.

关键词： collision detection projective transformation generalized characteristicpolynomial positional relationship

On the Complex Difference Equation of Hypergeometric Type on Non-uniform Lattices

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Acta Mathematica Sinica,English Series 2020年第5期36卷 487-511页

作者： Jin fa CHENG School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this article,we obtain a new fundamental theorems for Nikiforov-Uvarov-Suslov complex difference equation of hypergeometric type by the method of Euler integral transformation,its expression is different from Suslov’s *** also establish the adjoint equation for Nikiforov-Uvarov-Suslov difference equation of hypergeometric type on non-uniform lattices,and prove it to be a difference equation of hypergeometric type on non-uniform lattices as *** particular solutions of the adjoint equation are then *** an appliction of these particular solutions,we use them to obtain the particular solutions for the original difference equation of hypergeometric type on non-uniform lattices and other important results.

关键词： Special function orthogonal polynomials adjoint equation difference equation of hypergeometric type non-uniform lattice

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Radio jets and galaxies as cosmic string probes

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Frontiers of physics 2012年第4期7卷 461-470页

作者： fa-Bo Feng Department of Astronomy Nanjing UniversityNanjing 210093China

The lensing effect of a cosmic string is studied, and some new methods are proposed to detect the cosmic string. The technique for using jets as extended gravitational lensing probes was first explored by Kronberg. We use the ＂alignment-breaking parameter＂ nc as a sensitive indicator of gravitational distortion by a wiggly cosmic string. Then, we applied the non-constant deflection angle to jets, and na of a specific jet is just related to the projected slope of the jet. At least three jets in the sample of Square Kilometer Array （SKA） would have significant signals （na 〉 10°） if the wiggly infinite cosmic string existed. The distortion of elliptical object is also studied and used to do a statistical research on the directions of axes and ellipticities of galaxies. In the direction of the string, we find that galaxies appear to be more elliptical for an observer and the distribution of apparent ellipticity changes correspondingly. The ellipticity distribution of current SDSS spiral sample has the signal- to-noise ratio up to 8.48 which is large enough for astronomical observations. The future survey, such as Large Synoptic Survey Telescope （LSST） and Dark Energy Survey （DES） would weaken the requirement of special geometry in the data processing. As a result, all kinds of distributions, including ellipticity axis distribution, would serve as probes to detect wiggly strings in the near future. In brief, if a wiggly cosmic string existed, these signals would be convenient to be observed with the future weak lensing survey or other surveys in the deep space. If there was no lensing signal in these distributions, it would give the upper limit of the abundance of infinite strings.

关键词： gravitational lensing jets and outflows cosmic string galaxy

On spectrum of Hermitizable tridiagonal matrices

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Frontiers of Mathematics in China 2020年第2期15卷 285-303页

作者： Mu-fa CHEN Research Institute of Mathematical Science Jiangsu Normal UniversityXuzhou 221116China School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex Systems(Beijing Normal University)Ministry of EducationBeijing 100875China

This paper is devoted to the study on the spectrum of Hermitizable tridiagonal *** an illustration of the application of the author’s recent results on Hermitizable matrices,an explicit criterion for discrete spectrum of the matrices is presented,with a slight and technical *** problem is well known,but from the author’s knowledge,it has been largely opened for quite a long *** is important in various application,in quantum mechanics for *** main tool to solve the problem is the isospectral technique developed a few years *** alternative constructions of the isospectral operator are presented;they are helpful in theoretical analysis and in numerical computations,*** illustrated examples are included.

关键词： Hermitizable birth-death matrix isospectral matrices discrete spectrum

Prolongation structure for nonlinear integrable couplings of a KdV soliton hierarchy

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Chinese Physics B 2012年第11期21卷 18-23页

作者： Yu fa-Jun School of Mathematics and Systematic Sciences Shenyang Normal UniversityShenyang 110034China

In this paper, a new nonlinear integrable coupling system of the soliton hierarchy is presented. Prom the Lax pairs, the coupled KdV equations are constructed successfully. Based on the prolongation method of Wahlquis... 详细信息

关键词： nonlinear integrable coupling system prolongation structure KdV soliton hierarchy

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Fractional sum and fractional difference on non-uniform lattices and analogue of Euler and Cauchy Beta formulas

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Applied Mathematics(A Journal of Chinese Universities) 2021年第3期36卷 420-442页

作者： CHENG Jin-fa Department of Mathematics Xiamen UniversityXiamen 361005China

As is well known,the definitions of fractional sum and fractional difference of f(z)on non-uniform lattices x(z)=c1z^(2)+c2z+c3 or x(z)=c1q^(z)+c2q^(-z)+c3 are more difficult and *** this article,for the first time we propose the definitions of the fractional sum and fractional difference on non-uniform lattices by two different *** analogue of Euler’s Beta formula,Cauchy’Beta formula on non-uniform lattices are established,and some fundamental theorems of fractional calculas,the solution of the generalized Abel equation on non-uniform lattices are obtained etc.

关键词： difference equation of hypergeometric type non-uniform lattice fractional sum fractional difference special functions Euler’s Beta formula Cauchy’Beta formula

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Blending Canal Surfaces Based on PH Curves

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Journal of Computer Science & Technology 2005年第3期20卷 389-395页

作者： Chen-DongXu fa-LaiChen DepartmentofMathematics UniversityofScienceandTechnologyofChinaHefei230026P.R.China

In this paper, a new method for blending two canal surfaces is proposed. Theblending surface is itself a generalized canal surface, the spine curve of which is a PH(Pythagorean-Hodograph) curve. The blending surface possesses an attractive property - itsrepresentation is rational. The method is extensible to blend general surfaces as long as theblending boundaries are well-defined.

关键词： blending canal surface PH (Pythagorean-Hodograph) curve geometriccontinuity CAGD