关于有理函数的部分分式展开

有理函数是一类能求出原函数的重要函数类,其依据就是它有部分分式展开,然而一般的分析教材上却只讲有这个展开而无证明,或只是一笔带过。本文提供一种展开的方法,其根据是完全初等的恒等变形及适量的多项式除法,它的计算量一般比使用待系数法要小许多。     

关于一类不定积分的计算方法

利用导数讨论了形如∫dx/(x-a)^m(x-b)^n的不定积分的一种计算方法。     

利用自制电极测定渣油样品的电导率

质量分率电导率法可以用来表征渣油样品的胶体稳定性。利用上海雷磁仪器有限公司生产的DJS-1A型电导率仪,配以自制的小电极常数电极,测定了中东常压渣油在用正庚烷稀释过程中的电导率值,计算得到了不同正庚烷稀释比例时的质量分率电导率值,表征了中东常压渣油样品的胶体稳定性。结果表明,该装置测定结果与利用大型仪器——HP4194A型阻抗测试仪所得结果基本相同,说明该装置可以用来测定渣油样品的胶体稳定性。前者的造价远远低于后者。     

一种有理函数积分的简洁方法

本文从有理真分式分解为部分分式的一个简洁公式出发 ,讨论了有理函数积分的一种改进方法 ,相对于比较系数法而言 ,该方法更为简单、方便     

有限简单连分数的几个应用

讨论了有限简单连分数在分数约分、求最大公约数、解二元一次不定方程和一次同余方程中的应用。     

Measurement of oil volume fraction and velocity distributions in vertical oil-in-water flows using ERT and a local probe

INTRODUCTION The need for metering multiphase flow in the petroleum industry has been evident for many years. Considerable research has been conducted into this field for developing a suitable flowmeter which can be used in industrial environments. Various tech- nologies have been employed, and among which the tomographic techniques are increasingly being used. Process tomography is an emerging measure- ment technology with applications in a broad range of industries. It is non-invasive a…     

改进的割平面法求解整数规划

从线性规划问题着手,在利用单纯型法的时候,当约束矩阵中出现分数,利用初等的方法推导出定理1,给出一种"化分为整"的方法。然后在割平面方法来解决整数线性规划的理论基础上,利用初等数论中[x]和{x}的特性,推导出定理2,把"化分为整"的方法进行到底。     

Kinetic Study of Hydrothermal Stripping from Iron-Loaded Organic Phase

The iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene was prepared, and the process kinetics of hydrothermal stripping of iron from the phase was studied. Several factors affecting hydrothermal stripping, such as the polymer of naphthenic acid, initial concentrations of iron and naphthenic acid, temperature and agitation time, were investigated, and based on experimental results and theoretical analysis, two kinetic models were established.The stripping rate equation suggests that the hydrothermal stripping process activation energy is 96.4 kJ·mol-1 and the stripping is controlled by hydrolysis of naphthenic complex of iron. The values calculated by the stripping fraction equation comparatively accord with the experimental data.     

Numerical prediction of vortex flow and thermal separation in a subsonic vortex tube

INTRODUCTION Vortex tube is a device for producing hot and cold air when compressed air flows tangentially into the vortex chamber through the inlet nozzles. This causes the vortex and swirl flow movement inside the vortex tube. The air in the middle region of the tube has lower velocity and lower temperature than the inlet air. So the air near the tube wall has higher ve-locity and higher temperature than the inlet air. The cold air in the core region of the tube flows out through the o…     

基于超声的管道内粉体体积分数的测量

管道内粉体的气力输运广泛存在于化工、食品加工、电力、冶金和医药等工业生产过程中.通过对粉体颗粒的速度、体积分数和粒度等关键参数进行在线测量, 可实现过程优化控制, 提高生产效率和产品质量,降低能耗.本文从声散射理论模型出发,数值模拟并拟合出超声衰减系数和声速随粉体体积分数的变化关系.设计中心频率为30 kHz的一体式超声波探针,在杭州某水泥厂输运管道进行管内不同深度测点水泥生料粉体浓度的在线测量,分别以衰减和声速方法获得管内粉体沿径向的体积分数分布.