A theoretical model for mid-and low-latitude ionospheric electric fields in realistic geomagnetic fields

The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at mid- and low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model, and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.     

风洞风表检定仪8031系统研制

本文是在笔者最近研制的ＦＢＹ－１型风洞风表检定仪８０３１系统的基础上整理而成的，主要介绍了这个简单而实用系统的基本组成、软件设计以及针对现场实际问题所采用的有效措施     

压水堆控制棒导向筒结构改进对落棒的影响

为改善横向水力载荷对控制棒导向筒的作用，对靠近上腔室出口管嘴附近的控制棒导向筒（对称的４组：０２－２６，０３－２５，１１－２９，１２－２８）加设了保护套．在秦山核电站压水堆上腔室１４的可视化模拟体中，以水为介质进行了实验研究，把结果与未加设保护套的实验结果作了分析比较，得到了对靠近上腔室出口管嘴附近的控制棒导向筒加设保护套有助于改善流场对控制棒导向筒的水力载荷作用和确保控制棒能按指令在导向筒中自由升降和快速下插的结论．     

氯离子诱导的镍在硝酸溶液中的电流振荡

报道了氯了子诱导的镍在0．5mol.dm^-2硝酸溶液中活化－钝化过渡区电流振荡，在恒电位条件下，随着氯离子浓度的升高或者电极电位的降低，电流振荡由周期性振荡逐渐向非周期性振荡转变，根据实验结果，对该体系的电流振荡机理进行了讨论。     

On the Foundations of Constructive Mathematics – Especially in Relation to the Theory of Continuous Functions

We discuss the foundations of constructive mathematics, including recursive mathematics and intuitionism, in relation to classical mathematics. There are connections with the foundations of physics, due to the way in which the different branches of mathematics reflect reality. Many different axioms and their interrelationship are discussed. We show that there is a fundamental problem in BISH (Bishop’s school of constructive mathematics) with regard to its current definition of ‘continuous function’. This problem is closely related to the definition in BISH of ‘locally compact’. Possible approaches to this problem are discussed. Topology seems to be a key to understanding many issues. We offer several new simplifying axioms, which can form bridges between the various branches of constructive mathematics and classical mathematics (‘reuniting the antipodes’). We give a simplification of basic intuitionistic theory, especially with regard to so-called ‘bar induction’. We then plead for a limited number of axiomatic systems, which differentiate between the various branches of mathematics. Finally, in the appendix we offer BISH an elegant topological definition of ‘locally compact’, which unlike the current definition is equivalent to the usual classical and/or intuitionistic definition in classical and intuitionistic mathematics, respectively.     

锻炼对老年人肺通气功能影响的研究

本文采用电子肺活量计对218名老人进行了肺通气功能的测试。测试结果表明:体育锻炼对老年人肺通气功能有良好影响。本文为老年人肺通气功能的研究、评价及老年人体育运动的研究提供了实验性依据。     

气相法制备N－乙基苯胺催化剂的研究进展

对苯胺、乙醇气相Ｎ－乙基化反应催化剂的制备及其活性进行了评述，特别是对近十年来的发展作出了较详细而深入的论述，指出研制这类反应催化剂的重要性和今后的发展方向。     

条件不完全确定的发散思维型数学问题

“在条件A之下,会产生哪些、什么样的结果B”的问题,就是发散思维型的问题。若其中的条件A带有某种不确定成份,这就构成一种“条件不完全确定的发散思维型数学问题”。这种问题求解过程中的思维活动,有许多特点,对于培养学生的创造性思维有相当高的教育价值。本文以实例为基础对此做了讨论。     

粘结平面对称分叉裂纹的奇异积分方程数值解

本文对一个含分叉裂纹的弹性半平面与另一不同材料的半平面粘结的问题用复势方法化为一组三个复Caucby型奇异积分方程。采用修正的Gauss-Legendre和修正的Lobatto-Legendre数值求积法则化成一代数方程组,裂纹尖端的应力强度因子值可从代数方程组的解求得。本文计算得到了弹性半平面、刚体与弹性半平面相粘结、两种不同材料的弹性半平面相粘结的三种问题的几种几何形状的对称分叉裂纹的应力强度因子。本文的结果扩充了“应力强度因子手册”的内容。     

盾构隧道围岩与衬砌协同作用纵向位移计算法

盾构机掘进过程中,千斤顶顶进力的不均匀引起的纵向位移是管片间初始错台的主要原因之一;基于Timoshenko梁理论的隧道纵向位移计算方法,未能考虑隧道开挖后围岩卸载破坏的变形特征及围岩与衬砌结构的协同作用效应,预测误差较大。建立了考虑围岩卸载扩容效应的等效地基抗力系数计算方法,提出了能考虑螺栓个数的等效抗剪刚度计算公式,建立一种基于Timoshenko梁理论的改进管片拼装式隧道纵向位移理论计算方法。实际工程案例分析表明：考虑围岩开挖卸载过程中围岩的非线性体积相关塑性变形（即扩容效应）更合理;考虑壁后注浆液固化过程的时效性,采用改进的滑移边界条件计算的纵向位移最大值是传统的固定端边界的计算值的2.3倍,边界条件对计算结果影响较大,本文计算方法更符合实际情况,也更安全。