马尔可夫骨架过程的极限分布

本文运用基本更新定理和Smith关键更新定理等理论和方法,对马尔可夫骨架过程的极限分布进行深入研究,得到主要结果如下:去掉了原有结果中要求的绝对连续的条件,给出了马尔可夫骨架过程极限分布存在的充分条件;得到了马尔可夫骨架过程极限分布的具体公式,并证明了该极限分布为概率分布.     

一类抛物型方程有限元算法的计算准则

用有限元法分析瞬态温度场,很有可能得到“振荡”和“超界”的计算结果.这两种现象不符合热传导规律.为解决此问题,我们提出时间单调性和空间单调性的概念,推导出三维无源热传导方程的数值解的时间单调性的几组充分条件.对某些特殊边值问题,使用规则单元网格,可以得到合理结果时Δt/Δx2的上下界公式.文中还研究了空间单调性.最后我们还讨论了集中质量阵的算法.针对以热传导方程为代表的这一类抛物型方程的有限元算法,我们创造性地给出几组计算准则.     

对於“質量舆重量”一文的意見

在物理通報1954年1月號上登載了陳同新同志寫的“質量與重量”一文。我們對於其中關於“重量”方面的叙述有不同的意見,現在寫在下面: 首先是關於重量的定義問題,在該文中寫道:“什么是重量呢?我們知道,物體的重量是由地球的引力產生的,一個物體所受的地球引力的大小就是那個物體的重量,因此重量就是物體所受地球引力的大小的量度,也就是物體所受重力的量度,所以重量是一種力……”。在另一段中又寫道:“一個物體所受的地球引力(F),也就是它的重量(W),可以用下式來表示 W=F=fM/r~2m″     

LATEST PERMIAN AND EARLIEST TRIASSIC SEDIMENTARY PROVINCES AND THEIR FACIES TYPES IN SOUTH CHINA

During the latest Permian and earliest Triassic time, most parts of Tethys were entirely lacking in uppermost Permian (Changhsingian) and/or lowermost Triassic strata (Permian-Triassic transitional beds). However, these strata in South China arc not only well developed and widely distributed, but vary in lithofacies and biofaeies, usually forming a number of sedimentary regions and facies provinces. Accordingly, for the latest Permian strata two sedimentary regions and eight facies provinces have been recognized. In the earliest Triassic there were two sedimentary regions and four facies provinces in South China. It should be pointed out that the patterns of distribution for these regions and facies provinces were generally different during the latest Permian on the one hand and earliest Triassic on the other. This paper deals also with such problems as the changes of sedimentary environment climate and biotas in the period from the Paleozoic to the Mesozoic. It is evident that all of these lithofacies     

就北京市中学的情况談談如何进一步提高数学教学質量

解放以来,由于党和政府的关怀,中学教育已得到迅速的發展,教师的队伍也空前壯大?颖本┦械那榭隹蠢?中学的数学教师较解放初期就增加一倍以上。因为教师的业务基础比较悬殊,教学水平参差不齐,且青年学生寻求知识     

本卷“多維平稳过程的預測理論(Ⅰ)”一文的勘誤

<正> 1)p.275第22行“Φ_(,n×n)”应改为“Φ_(n×n),” 2)p.279倒第4行“其中x_k(t)代表x_k(t)在H_x(0)的投影”改为 “其中x_k(t)代表x_k(t)在H_x(0)的投影”,     

CRYSTAL AND MOLECULAR STRUCTURES OF BIS (CYCLOPENTADIENYL) BIS (2,4,6-TRICHLOROPHENOXY)TITANIUM, Cp_2Ti(OC_6H_2Cl_3-2,4,6)_2 (Ⅰ) AND TETRAKIS(CYCLOPENTADIENYL)BIS (4-CHLOROPHENOXY)-μ-OXO-DIZIRCONIUM,[Cp_2Zr(OC_6H_4Cl-p)]_2O (Ⅱ)

The crystal and molecular structures of (Ⅰ) and (Ⅱ) have been determined from single-crystal, X-ray diffraotion data collected by counter methods. Compound (Ⅰ) crystallizes inthe monoclinic space group C 2/c with a=19.618(11) ?, b=9.356(4) ?, c=15.985(8) ?,β=128.84 (3)°, Z=4. The molecule possesses C_2 point symmetry. Compound (Ⅱ) erystallizesin the monoclinic space group P 2_1/a with a=8.329(2) ?, b=36.509(13) ?, c=10.647(4)?, β=96.04(2)°, Z=4. The oxo-bridge links two [Cp_2Zr(OC_6H_4Cl-p)] units together withthe bond angle Zr-O-Zr of 161.1(9)°. The relatively shorter Zr-O bond lengths show the pre-sence of partial double-bond character. Both Ti and Zr atoms have d° electronic configura-tion in (Ⅰ) and (Ⅱ). The M-O bonds of the two compounds are discussed.     

Navier-Stokes方程的求解和均匀各向同性湍流理论——理论与计算方法

本文是文献[1]的进一步发展。目的是要解决均匀各向同性湍流从衰变初期到衰变后期的整个流动问题。文中提出了一种求解Navier-Stokes方程的展开方法,得到了一组无穷多个二阶非线性偏微分方程。本文只考虑了零级近似。我们利用富利埃变换方法,在波数空间得到一个振幅函数所满足的非线性积分-微分方程。它实质上就是能谱的动力学方程。在下一篇文章中,将给出数值计算的结果和与现有实验的比较,两者符合是相当满意的。