关于一个非线性几何光学中的非严格双曲守恒律系统的研究

研究了一个产生于非线性几何光学中的非严格双曲守恒律系统.该系统具有强非线性流函数项,且狄拉克激波可能同时出现在解的两个状态变量中.通过未知函数的一个变换,该系统的非线性流函数项得到弱化,从而其黎曼问题被完全解决.     

一维Chaplygin气体欧拉方程组中波的相互作用

研究一维Chaplygin气体欧拉方程组中波的相互作用.方程组的波包含接触间断和在密度变量以及内能变量上同时具有狄拉克函数的狄拉克激波.根据这些波的不同组合,问题被分成了7种情形.通过详细地构造每种情形的整体解,获得了各种波相互作用的完整结果.特别地,对于一类初值,两个接触间断相互作用后,产生了一个狄拉克激波;然而,对于另外一类初值,一个狄拉克激波与一个接触间断相互作用后,狄拉克激波消失.这些都是波相互作用中非常特别的现象.     

带群集耗散项的零压流方程的扰动黎曼问题

该文通过分析带群集耗散项的零压流方程初始波含狄拉克激波的波的相互作用,研究了其初值含三片常值和初值含狄拉克测度的两种扰动黎曼问题.当初值为三片常值时,通过广义Rankine-Hugoniot条件和广义熵条件,该文构造性地得到了整体解.进一步地,利用弱解的稳定性理论,通过分析初值为三片常值情形下解的结构并取极限,该文得到了初值含狄拉克测度的扰动黎曼问题的整体解.另外,在构造解的过程中,还引入了一种新的非经典解:狄拉克接触间断解.     

具有常外力项的零压欧拉方程组初值涉及狄拉克函数的黎曼问题

研究具有常外力项的一维零压欧拉方程组初值涉及狄拉克函数的黎曼问题.首先,研究对应的扰动初值问题;其次,基于一维非线性守恒律方程组弱解的稳定性理论,通过分析对应的扰动初值问题解的极限,最终得到了6类显示解.特别地,对于某些初值,捕捉到了在密度变量和内能变量上同时涉及狄拉克函数的狄拉克接触间断,这是一类重要的非线性现象.此外,这些结果清晰地刻画了常外力项对解结构的影响.     

延拓Chaplygin气体黎曼解的流逼近极限过程中的集中性研究(英文)

本文研究了延拓Chaplygin气体的黎曼解在流逼近极限过程中的集中现象和狄拉克激波的两种形成机制问题.利用相平面分析法和广义特征分析法,构造出了延拓Chaplygin气体的整体黎曼解,并获得了两个结果:当压力消失时,延拓Chaplygin气体的包含两个激波的解收敛到输运方程的狄拉克激波解;当压力项趋近于广义Chaplygin压力项时,延拓Chaplygin气体的包含两个激波的解收敛到广义Chaplygin气体的狄拉克激波解.结论推广到了延拓Chaplygin气体.     

粘滞性粒子动力学中的二维非自相似初值问题

研究了二维粘滞性粒子动力学中的非自相似初值问题．该初值被一圆环分为内外两块常状态．利用广义特征分析的方法和广义Rankine-Hugoniot关系,该关系是常微分方程组,一个包含狄拉克激波和真空的整体解被构造性地得到．     

电子、磁单极子和光子的相互作用(Ⅰ)

利用处理磁单极谐函数所发展起来的方法,我们提出了电子、磁单极子和光子相互作用的二次量子化理论.在第一篇文章中我们讨论相互作用的电子、磁单极子和电磁场系统.其中,电子和磁单极子被当作自旋1/2的狄拉克粒子,且暂不考虑负能态.     

含有中间幂等元满足同余条件的◇-富足半群

本文引入了--格林关系和--富足半群,研究了满足同余条件含有中间幂等元的--富足半群.利用具有中间幂等元的由幂等元生成的正则半群和◇-拟恰当半群建立了满足同余条件含有中间幂等元的◇-富足半群的结构.     

一类含有分数阶导数的二自由度耦合系统

研究了一类含有小扰动具有分数阶导数的二自由度耦合振子的振动问题.首先对含有由Riemann Liouville定义的分数阶导数的振动方程组构造渐近解,利用多重尺度法,得到振动问题的可解性条件.然后在可解性条件下,得到分数阶指数、系数及小参数对振动的影响,并求得渐近解.最后研究了该解的稳定性,发现定常解都是稳定的     

一类二阶微分方程的特征值估计及其反问题

借助Rouché定理及渐近分析的方法,给出了边界条件含有特征参数的一类二阶微分方程的特征值渐近公式.运用特征值渐近公式给出了特征值反问题的一个惟一性结果及重构公式.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].