Nonlinear Electrodynamic Delay of Electromagnetic Signals in a Coulomb Field

We study the motion of electromagnetic signals in the Coulomb electric field of a compact gravitating center under the laws of the parameterized nonlinear electrodynamics of the vacuum. We evaluate the deflection angles of the rays along which the electromagnetic waves of two normal modes propagate in this field. We determine the nonlinear electrodynamic delay of the electromagnetic signal of one normal mode relative to the electromagnetic signal of another normal mode during their propagation from the same source to an observer.     

在伽玛-指数模式下串联结构系统可靠度估计

设结构系统由ｎ个结构性部件串联组成．设部件ｋ的强度Ｘｋ服从指数分布厂Г（λ，１），λ＞０，ｋ＝１，２，…，ｎ；系统应力Ｙ服从Ｇａｍｍａ分布Г（μ，α），μ，α＞０．当α已知，λ，μ未知时，本文给出串联结构系统可靠度ＲＲ的ＭＶＵＥＲＲ和ＭＬＥＲＲ．证明了ＲＲ和ＲＲ都是ＲＲ的相合渐近正态估计．     

球面导数，高阶导数与正现族

本文应用陈怀惠和顾永兴关于Ｚａｌｃｍａｎ不正规性条件的改进结果，推广和加强了Ｌａｐｐａｎ的一个正规定则．Ｌａｐｐａｎ证明：若亚纯函数族中的所有函数的球面导数的幂方（大于２）在紧集上的积分一致有界，则该族是正则的．本文证明，把积分限制在函数值的模小于给定常数的子集上，结论仍然成立．同时，用高阶导数的积分替代球面导数的积分，得到十分一般的结果．另外对幂方为２的情形也进行了讨论．     

原子核的振动与转动模型(Ⅱ)奇A核正常转动谱分析

应用推转玻尔-莫特逊哈密顿量,对奇A核正常转动带进行分析,对模型适用条件及其与Harris展开式的比较作了讨论.     

Static analysis of functionally graded beams using higher order shear deformation theory

Displacement field based on higher order shear deformation theory is implemented to study the static behavior of functionally graded metal–ceramic (FGM) beams under ambient temperature. FGM beams with variation of volume fraction of metal or ceramic based on power law exponent are considered. Using the principle of stationary potential energy, the finite element form of static equilibrium equation for FGM beam is presented. Two stiffness matrices are thus derived so that one among them will reflect the influence of rotation of the normal and the other shear rotation. Numerical results on the transverse deflection, axial and shear stresses in a moderately thick FGM beam under uniform distributed load for clamped–clamped and simply supported boundary conditions are discussed in depth. The effect of power law exponent for various combination of metal–ceramic FGM beam on the deflection and stresses are also commented. The studies reveal that, depending on whether the loading is on the ceramic rich face or metal rich face of the beam, the static deflection and the static stresses in the beam do not remain the same.     

Branching Numbers for Euclidean Projections onto Convex Polyhedra

The purpose of this note is to give a short proof of the theorem of Ralph in Linear Algebra Appl. 178 (1993), 249–260, on the geometry of projection maps. This theorem implies that the so-called normal maps derived from projections satisfy a general geometric criterion for bijectivity of piecewise affine maps given by Kuhn and Löwen in Linear Algebra Appl. 96 (Section 5.3), (1987), 109–129. As a consequence, one obtains Robinson's characterization of bijectivity of normal maps.     

Free vibrations of a thin elastica by normal modes

In this work we investigate the existence, stability and bifurcation of periodic motions in an unforced conservative two degree of freedom system. The system models the nonlinear vibrations of an elastic rod which can undergo both torsional and bending modes. Using a variety of perturbation techniques in conjunction with the computer algebra system MACSYMA, we obtain approximate expressions for a diversity of periodic motions, including nonlinear normal modes, elliptic orbits and non-local modes. The latter motions, which involve both bending and torsional motions in a 2:1 ratio, correspond to behavior previously observed in experiments by Cusumano.     

椭圆型变分不等方程最优控制的必要条件

本文用 F.H.Clarke 的非光滑分析方法,在目标泛函 Lipschitz 的条件下,导出了椭圆型变分不等方程系统最优控制的必要条件,并证明有界最优控制是阀值 Q=0 的Bang-Bang 开关控制。     

强Duffing系统的局部分岔分析

本文通过坐标变化和近恒等变化，将强Ｄｕｆｆｉｎｇ方程化成范式，从而可以得到在不同共振条件下的分合方程以及其近似解，应用奇异性理论研究了强Ｄｕｆｆｉｎｇ在开折参数及物理参数平面上的转迁集及其局部分岔图．