电磁场的势A和φ的微分方程的独立性

将矢量场分解为纵场和横场，比较电磁场的矢势Λ的φ分方程与标势中的微分方程在规范条件下所得的结果．论证了在规范条件下标势φ的方程的不独立性．     

调运问题的新解法──元素判别值分配法的研究与实现

对运筹学的调运问题提出一种新解法──元素判别值分配法.它不同于国内外现行的任一种方法,只须一次调配即获最佳方案,不必进行调整.此法既便于人工操作,又易于程序实现.     

压电陶瓷圆柱振子的本征模式研究

压电陶瓷圆柱振子的本征模式研究林书玉，张福成（陕西师范大学应用声学研究所，西安７１００６２；第一作者，男，２９岁，副教授）当圆柱状换能器的高度与半径相差很大时，其振动可看成是一维的径向或轴向振动．然而当振子的半径与高度处于同一量级时，其振动模式不同于...     

数据库的通用输出接口

对BASIC语言和关系数据库dBASEⅢ的优点进行了综合,从理论上阐述了在BASIC状态下直接读取关系数据库dBASEⅢ的数据以及数据处理—图形输出的可行性与算法分析;并给出了程行的流程图和一个图形输出实例。     

非线性系统两变量控制下的分枝特性

采用分枝理论推导非线性系统两变量P和PI控制下的分枝特性,所导得的几个定理阐明了简单分枝点和Hopf分枝点的位置和性质。一个简化精馏塔模型用于演示这一过程,展示出精馏塔系统在闭环时,可能出现多态和极限环。     

一类二阶导数非线性Schrdinger方程的初边值问题

本文研究一类二阶导数非线性schrdinger方程的初边值问题.在空间区域为星形域和引入的初值能量分别大于或等于零及小于零情况下,得到初边值问题之解在有限时间内爆破.     

无界域上含临界指数的P—Laplace方程的非平凡解

给出无界域上含临界指数的P-Laplace方程:(2≤p相似文献   

等价鞅测度模型在欧式认股权证定价中的应用

介绍了认股权证,并利用等价鞅测度定理给出欧式认股权证定价的一般公式,如修正一些基本假设,可推导一些应用于特殊情况的权证定价公式.     

中锰白口铸铁热塑性变形规律的探讨

为开发磨球成形新工艺——水平连铸白口铸铁棒材斜轧成球的工艺。采用高温压缩、高温扭转试验方法，研究了中锰白口铸铁的高温塑性变形能力，测定了温度与极限变形率，温度与变形抗力的关系曲线。对塑性变形后的组织进行了分析。结果表明：中锰白口铸铁在８５０～１０００℃具有良好的塑性变形能力，热塑性变形后碳化物成断网状和孤立块状，从而可使中锰白口铸铁的韧性提高     

Morphology and quantitative analysis of O phase during heat treatment of hot-deformed Ti_2AlNb-based alloy

A 1040°C-hot-deformed Ti_2AlNb-based alloy solution-treated at 950°C and aged at different temperatures was quantitatively investigated. The microstructure, size of the phase, and microhardness of the deformed alloys were measured. The results indicated that the microstructure of the deformed Ti_2AlNb-based alloy specimens comprise coarse O lath, fine O lath, equiaxed O/α_2, and acicular O phase. More O phase was generated in the deformed alloy after heat treatment because the acicular O phase was more likely to nucleate and grow along the deformation-induced crystal defects such as dislocations and subgrain boundaries. After deformation and subsequent heat treatment, the acicular O phase of the resultant alloy became finer compared to that of the undeformed alloy, and the acicular O phase became coarser and longer with the elevated aging temperature, while the width of the O lath exhibited unobvious variations. The hot deformation facilitated the dissolution of the O lath but accelerated the precipitation of the acicular O phase. When the 950°C-solution-treated deformed Ti_2AlNb-based alloy was then aged at 750°C for different periods, the phase content was nearly invariable, O and B2 phases eventually reached equilibrium, and the microstructure became stable and homogeneous.