On meromorphic solutions of <Emphasis Type="Italic">f</Emphasis><Superscript>2</Superscript> + <Emphasis Type="Italic">g</Emphasis><Superscript>2</Superscript> = 1

We show that meromorphic solutions f, g of f ² + g ² = 1 in C² must be constant, if f _z2 and g _z1 have the same zeros (counting multiplicities). We also apply the result to characterize meromorphic solutions of certain nonlinear partial differential equations.     

Research on La–Co-substituted strontium ferrite magnets for high intrinsic coercive force

M-type strontium ferrites with substitution of Sr²⁺ by rare-earth La³⁺, and a little amount of Fe³⁺ by Co²⁺ according to the formula Sr_1−xLa_xFe_12−xCo_xO₁₉, are prepared by the ceramic process. Effects of the substituted amount of La³⁺ and Co²⁺ on structure and magnetic properties of Sr_1−xLa_xFe_12−xCo_xO₁₉ compounds have systematically been investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and B–H hysteresis curve measurements. In our results, the suitable amount of La³⁺–Co²⁺ substitution may remarkably increase saturation magnetization. Intrinsic coercive force (H_cj) of Sr ferrite magnets is evidently increased without significant decrease in residual flux density (B_r) by La³⁺–Co²⁺ substitution.     

裂变碎片动能和质量分布的三维朗之万研究

采用一个具有协变形式的朗之万方程组来描述不对称热核裂变.基于核表面｛c,h,α｝三参数模型,用数值方法模拟了核系统从鞍点到断点的扩散过程,从而完成了碎片动能和质量分布的计算.研究了核的两体摩擦或一体耗散机制以及有限颈部作为核断裂条件对裂变碎片输出量的影响.     

The regularity of the surface of the Gauss curvature 0≤K ∈ C 0 ∞

Under the mild conditions, it is proved that the convex surface is global C^1.1, with the given Gaussian curvature 0≤K ∈ C ₀ ^∞ and the given boundary curve. Examples are given to show that the regularity is optimal. Project supported by the Doctoral Funds of China and the National Natural Science Foundation of China (Grant No. 19771009).     

乙烯和乙炔基在Ni(110)表面上吸附结构的研究

采用平面波赝势方法，利用基于从头计算的软件包，对乙烯和乙炔基在Ni(110)表面上吸附的问题进行了计算. 在低覆盖度时，孤立的乙烯分子的吸附能比密集时高，乙烯分子的C-C 轴大致沿衬底的Ni原子链方向(即沿［110］晶向)，C-C轴与衬底Ni(110)表面有12°的倾斜角，乙烯分子的C—C键的键长为 0.147nm. 乙烯分子中接近顶位的C原子与衬底中距离最近的Ni原子为0.199nm. 在高覆盖度时，乙烯分子在Ni(110)表面上形成c(2×4)再构，每个表面二维元胞中有两个乙烯分子，每个乙烯分子的吸附位置与低覆盖度时相似，而C—C键长比低覆盖度时要短. 乙炔基是乙烯在Ni(110)表面上分解的产物. 关于乙炔基的计算结果表明：乙炔基的两个C原子的间距为0.131nm，比乙烯分子中C原子的间距更短. 与乙烯分子相比，乙炔基的吸附位置更靠近顶位. H原子与吸附在顶位上的C原子相连接，C—H键也大致沿衬底的Ni原子链方向，与Ni表面呈45°的倾斜角. 关键词： 乙烯和乙炔基 平面波赝势方法 吸附几何结构     

高压超快光导开关输出电脉冲的瞬态分析

本文从载流子连续方程出发,根据高偏压光电开关中载流子的运动以迁移为主的特点,在不同的激励光脉冲参量和开关尺寸的情况下,对开关输出电脉冲的瞬时特性进行了数值计算,为光导开关的设计和实验研究提供了依据。     

Precise Large Deviations for Sums of Negatively Associated Random Variables with Common Dominatedly Varying Tails

In this paper, we obtain results on precise large deviations for non-random and random sums of negatively associated nonnegative random variables with common dominatedly varying tail distribution function. We discover that, under certain conditions, three precise large-deviation prob- abilities with different centering numbers are equivalent to each other. Furthermore, we investigate precise large deviations for sums of negatively associated nonnegative random variables with certain negatively dependent occurrences. The obtained results extend and improve the corresponding results of Ng, Tang, Yan and Yang （J. Appl. Prob., 41, 93-107, 2004）.     

A 3-color Theorem on Plane Graphs without 5-circuits

In this paper, we prove that every plane graph without 5-circuits and without triangles of distance less than 3 is 3-colorable. This improves the main result of Borodin and Raspaud [Borodin, O. V., Raspaud, A.： A sufficient condition for planar graphs to be 3-colorable. Journal of Combinatorial Theory, Ser. B, 88, 17-27 （2003）], and provides a new upper bound to their conjecture.     

Rindler effect for a nonuniformly accelerating observer

Both the Klein-Gordon equation and the Dirac equation are dealt with in the generalized Rindler space-time of a nonuniformly accelerating observer. Making use of a new method and introducing a tortoise-type coordinate transformation, it is proved that there exist an event horizon and thermal radiation depending on time in the space-time. The Hawking-Unruh temperature is proportional to the variable acceleration.