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。     

ECL805三极管接法推挽功率放大器的制作

电路介绍 ECL805是18GV8的6.3V品种,最大屏极损耗为7W.据笔者调查,该管仅欧洲的飞利浦(1970年)、德律风根(1974年)等厂商有过生产记录,美、日的数据手册中难觅其行踪.ECL805的五极管部分,其屏极电流约为6BM8的1.5倍,性能直逼6CW5.     

反射式可调移相器

针对现代通信中线性功率放大器的补偿要求,介绍一种利用反射理论设计可调移相器,实现大范围移相,同时幅度波动很小,并详细讨论了它的工作原理和实验结果。     

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.     

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:     

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.     

北京谱仪Ⅱ顶点探测器的径迹重建

描述了采用模式识别方法的北京谱仪Ⅱ顶点探测器径迹重建软件系统─—VCJULI.经过蒙特卡罗和真实数据的运行检查,证明该程序能对顶点探测器的径迹给出较好的空间分辨和径迹寻找效率.     

介紹試教“數的開平方”的几點經驗

我系本屆(1955年教育实習)实習生試教中,關於“數的開平方”运用了幾何解釋与代數推理相結合的方法,試教結果証明:运用这种方法比之於运用純幾何或純代數推理更能使学生理解並掌握數的開平方的法則(數的開平方的幾何解釋是根据苏联伯拉基斯著中学數学教学法中提示的)。此外关於誤差小於1/10,1/100,…的近似极的概念及小數開平方的講法也有一些收穫,現在一併介紹於下。 1.100以上10000以下數的開平方 (1) 預备知識: (a)求某数平方根的幾何意义就是求面積等于某數(平方單位)的正方形的边長。 (b)三位數、四位數的平方根必定是一个兩位數。