具转向点常微分方程混合边值问题的一致收敛差分格式

本文得到了具转向点的二阶常微分方程混合边值问题解的导数估计,提出了Il′in型差分格式,证明了此差分格式按L~1模关于小参数ε的一阶一致收敛性。最后,给出了一个数值例子,计算结果与理论分析一致。     

固态硫酸锂—水合物脱水过程的非等温动力学

采用TG-DTG技术研究了固态硫酸锂-水合物脱水过程，运用Malek等提出的热分析动力学数据处理方法，确定了脱水过程的动力学机理模式f(a)为n(1-a)[-ln(1-a)]^1-1/a或为a^n(1-a)^n，并求得相应动力学参数。     

数学之神——阿基米德

近代数学史家倍尔说,任何一张列出有史以来三个最伟大的数学家的名单中,必定会包括阿基米德,另外两位通常是牛顿和高斯.其实,早在公元1世纪就有人称阿基米德为“数学之神”.阿基米德到底是怎样的一尊“神”呢? 阿基米德,公元前287年生于意大利半岛南端西西里岛的叙拉古城,他有一位当天文学家的父亲,他从小就受到了良好的家庭教育.后来,阿基米德的亲戚当上了叙拉古国王,又使他有机会飘洋过海,到号称“智慧之都”的亚历山大城学习.在那里,阿基米德受到了良好的数学教育,结交了不少著名学者.返回叙拉古后,阿基米德毕生从事研究工作.     

纳米二氧化钛催化合成乙酸丁酯的研究

以纳米TiO2为催化剂催化合成乙酸丁酯,并考察了各种因素对反应的影响。结果表明:当醇酸摩尔比为1.5:1、催化剂用量为0.8g、反应时间为2.5h、带水剂环己烷为10ml时,其酯化率可达95.8%。该催化剂具有较高的催化活性,不污染环境。     

关于等比数列定义的探讨

本文将讨论有关等比数列的几个关系式的等价性,从而深入地探讨等比数列的种种定义,同时兼论一些数学书籍和资料中关于等比数列问题解答上的失误。(一) 在不少数学书籍、刊物和资料中,常见到有这样的结论:     

浅谈化学实验教学中的思维训练

论述了化学实验教学中强化思维训练的原因，围绕实验原理引导学生展开思维活动。通过实验中的思维训练。得出：要想提高化学实验教学质量，加强思维训练至关重要。     

关于舰船动力现代化

多兵种的现代海军,舰船是其基本组成部分,动力则是舰船的心脏。因此,舰船动力的发展对海军现代化十分重要。这里,我想谈一谈舰船动力的现代化问题,主要讲常规动力的发展,重点为舰船燃气轮机。     

NETS IN MULTISYSTEMS OF n 3 AND n 4 PHASES

From the free energy surfaces in G-p-T space a series of basic characteristics have beensummarized. For the reactions of most systems with phases of constant composition, eachof the surfaces should be approximate to a plane. After they meet, the points, curves andsurfaces possess distinct stability levels. Across the intersecting curves and points, the freeenergy surfaces and curves will change their stability levels. Linking invariant points ofdistinct stability levels, we can get various univariant curves differing in structure. Theangular extent between two univariant curves around the invariant points is less than 180°.The surfaces meeting in space and projecting onto the p-T section will give rise to partiallyclosed or open, rather than completely closed nets. Finally, based upon the basic characteristicsand criteria, we have derived the partially closed nets of n 3 and n 4 phases with maxi-mum closure by using geometrical and analytical methods. From the free energy surfaces in G-p-T space a series of basic characteristics have beensummarized. For the reactions of most systems with phases of constant composition, eachof the surfaces should be approximate to a plane. After they meet, the points, curves andsurfaces possess distinct stability levels. Across the intersecting curves and points, the freeenergy surfaces and curves will change their stability levels. Linking invariant points ofdistinct stability levels, we can get various univariant curves differing in structure. Theangular extent between two univariant curves around the invariant points is less than 180°.The surfaces meeting in space and projecting onto the p-T section will give rise to partiallyclosed or open, rather than completely closed nets. Finally, based upon the basic characteristicsand criteria, we have derived the partially closed nets of n 3 and n 4 phases with maxi-mum closure by using geometrical and analytical methods.     

低速潜油电机的研究

以１８槽电机为基础，分析和研究了电机设计的最多磁级数。通过分析提出１８槽电机分数槽绕组的镜像方法，并确定出能满足螺杆泵转速要求的最少槽数。     

长江流域刀鲚鱼生殖洄游的“生物指标”

一九七三年至七五年,我们试以刀鲚(Coilia ectines Jordan et Seale)体上的寄生虫作为“生物指标”,来对刀鲚鱼在长江流域的生殖洄游情况进行探讨,同时用同样的方法对长江流域的几种鲚属鱼类是否进行成、淡水的生殖洄游问题进行研究。结果表明:中国上棒鲺颚(Epiciavella chinensis Yu, 1933),简单异尖线虫的幼虫[The larva of Anisakis(Anisakis)simplex]和河蚌的钩介幼虫(The lalva of Anodonta woodiana pacifica)等三种寄生虫可以作为“生物指标”来判定鲚属鱼类是否进行成,淡水的生殖洄游。刀鲚鱼是江海洄游的种类,短颌鲚(C. brachygnathus Kreyenberg et Pappenheim),太湖湖鲚(Coilia sp.)和夙鲚(C. mystus L.)是不进行成,淡水洄游的种类。文中并列有刀鲚鱼体内外的寄生虫名录23种。