锥形壳体按中径公式设计的限定条件

按GB150《钢制压力容器》的规定,圆筒形壳体、球形壳体和锥形壳体的壁厚都可按中径公式进行计算,且对圆筒形壳体和球形壳体给出了公式应用的限定条件,但对锥形壳体却没有给出限定条件.通过对圆筒形壳体和锥形壳体薄膜应力及壁厚计算公式的分析和比较,提出了锥形壳体按中径公式计算壁厚时的限定条件.     

Experimental study on premix combustion at isosceles triangle type rate of heat release for squish type combustion chamber

This paper presents a theory on premix fuel combustion at near isoceles triangle type rate of heat release, describes the measures taken for the combustion system, points out its many theoretical advantages, and that it can solve effectively the problems of rough running, fuel consumption and exhaust emission. Two squish lip type combustion chambers are designed to match separately with multiple holes injector and conical spray type injector in order to achieve premix combustion at near isosceles triangle type rate of heat release. Experimental studies on two single cylinder diesel engines showed that premix combustion at isosceles triangle type rate of heat release resulted in longer ignition delay period, larger amount of fuel injected into cylinder during the ignition delay period, lower maximum pressure, better fuel economy, and better exhaust emission.     

一类函数留数计算的两个简化方法

在传统计算留数的常用方法的基础上介绍了两个新的定理,把孤立奇点处的留数计算简化,尤其是对于奇(偶)函数在孤立奇点处的留数更加简化。     

奇异非线性二阶三点边值问题正解的存在性

应用Schauder不动点定理,建立了奇异非线性三点边值问题u″(t) f(t,u(t))=0,00,f∈C((0,1)×[0, ∞)).     

一类带奇异项的半线性椭圆型方程的不变解

主要研究一类带奇异项的半线性椭圆型方程在,Ω=Ω1×Rd条件下的不变解的存在情况。若Sλμ,(Ω,G)相似文献   

Laurant展开的技巧

数学物理方法教材只提供复变函数洛朗 (Laurant)展开的基本方法 ,实际将任给复变函数展开成为洛朗级数的过程都比较复杂 .通过深入研究 ,我们发现洛朗展开有一定的技巧性 .我们给出洛朗展开的技巧性方法和用计算机系统来展开的方法     

基于Java3D的网络虚拟实验的开发

Java3D是一种新的三维构建技术,它应用于网络虚拟实验的开发可极大提高实验的仿真效果和交互能力。在大学物理虚拟实验的开发实践中总结了基于Java3D开发虚拟实验的一般流程和常见疑难处理方法,以离心节速器实验为例描述了具体的应用开发过程,提出了开发三维虚拟实验的极具可操作性方案。     

关于E_0的Steiner邮路问题的转化求解

简述了图论中的中国邮路问题的求解方法,设法将有两个连通分支的子图转化为中国邮路问题,从而求解那些满足E0的Steiner邮路问题边界条件的两个连同分支问题。     

Singularity Theory on Buckling of Compressible Slender Rods with Deformation of Cross Section

The crucial effect of compressibility of rods on their instability is novelly demonstrated via singularity theory. It is shown that the critical load of compressible rod is always greater than the one of the Euler rod, and a subcritical pitchfork bifurcation, which cannot occur for the Euler rod, may occur for a compressible rod. A whole bifurcation diagram of compressible rods is as follows: when the original slenderness ratio of a compressible rod, S0, is smaller than , the rod does not buckle; when ,the rod may undergo a subcritical pitchfork bifurcation and a collapse may occur; when , the rod may undergo a supercritical pitchfork bifurcation. The deformation of cross section of rods causes a little shift of bifurcation points towards to the one corresponding to larger slenderness ratio.     

《构造地质学》中赤平投影问题的讨论

《构造地质学》中,“不过球心的平面”的说法有待商榷。在“极射赤平投影”的概念下,所有倾斜平面都假定通过球心,其赤平投影为一个大圆弧。赤平面上的小圆是圆锥面的投影。建议教材内容和排序适当调整。