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Based on wave propagation feature, this paper analyses 3D seismic migration algorithms such as alternating direction implicit method, LU decomposition method, and inverse operator approach method. The result shows that the alternating direction implicit method is fast but causes distortion in wave field extrapolation and affects image accuracy; however LU decomposition and inverse operator approach methods are fast while holding circular symmetry of wave field, and are promising in oilfield exploration and development.

在波的传播特征分析基础上，对交替方向隐式法、LU分解法、逆算子逼近法等三维地震偏移算法进行了分析研究，结果表明，交替方向隐式法虽然快捷但是在波场外推中明显产生畸变并影响成像的准确性，而LU分解和逆算子逼近法是保持波场圆对称特征前提下的快速算法，在油田勘探开发中具有较好的应用前景。

The inverse kinematics algorithm of redundant robot is studied in depth in this dissertation, especially the apery arm-7 d. o. f. robot. The apery arm robot system is an important technology for nucleus industry, space station and other remote telecontrol tasks.

本文对冗余度机器人逆运动学算法问题进行了较为深入的研究，尤其对七自由度拟人手臂机器人逆运动学的研究，具有一定的实际意义；所设计的拟人手臂机器人系统对于核工业、空间站以及其它远程遥控作业自动化具有重要意义。

In this paper we use pointwise modulus of smoothness to study approximation direct theorem and equivalent theorem for some linear operators and quasi-interpolant operators; Using pointwise modulus we discuss the strong converse inequality on K-functional; and using a modified weighted K-functional and weighted modulus of smoothness we study approximation with Jacobi weight on operator with non-zero first order moments.

本文利用点态光滑模ω_~(2r)来研究某些线性算子及逆中插式逼近正定理和等价定理；利用点态光滑模讨论其关于K-泛函的强逆不等式；同时利用一种改变的带权K-泛函和带权光滑模研究一阶矩不为零的算子的点态带Jacobi权逼近。

To obtain the function and imbedding properties about relative countable tightness spaces,in this paper the question whether the relative countable tightness space can be adversely preserved by a closed map is studied by means of function and imbedding theories.

为了得到相对可数紧度空间的映射及嵌入性质，借助映射方法和紧化理论讨论了相对可数紧度空间被闭映射逆保持问题及嵌入紧空间问题，得到了相对可数紧度空间被闭映射逆保持的一个充分条件、局部紧的可数紧度空间可嵌入紧空间的几个充分条件以及某一类局部紧空间在任意紧化中不具有可数紧度等结果。

In order to solve the application problem of conduction heating machining, this project investigates some problems, such as dynamic characteristics of heating power, features of circuit current and voltage, arc discharge states and so on. It also studies control characteristics of Uni-phase or Tri-phase Direct Current Power Supply and Inverse Switch Power Supply. A High Frequency Inverse Switch Commutate Power Supply is developed.

为了解决导电加热切削的应用问题，从加热电源的动态性能和回路的电流、电压特性及电弧放电状态等方面进行研究，分析比较了单、三相交直流电源和逆变开关电源的特点和控制特性，研制了高频逆变开关整流电源。

The extracted P-wave is reverse-time extrapolated and imaged with a P-velocity model using a finite difference solution of the scalar wave equation, the extracted S-wave is reverse-time extrapolated and imaged similarly, but with an S-velocity model, and converted S-wave data requires a polarity correction prior to migration to ensure constructive interference between data from adjacent source.

在模型中，每个网格点的纵、横波成像时间，为震源到该网格点的纵波初至时间。利用纵波速度模型和声波传播方程的有限差分解，对反射纵波进行逆时延拓和成像，利用横波速度模型和声波传播方程的有限差分解，对转换横波进行逆时延拓和成像，并在偏移前进行极性校正。

The present paper proposed one kind of numerical control single-phase inversion structure, in detail elaborated the system parameter design, the rectification work basic principle of work, the contravariant basic principle and the SPWM sine pulse width modulation.

本论文提出了一种数字控制的单相逆变器结构，详细论述了系统的参数设计，整流工作的基本工作原理，逆变的基本原理及SPWM正弦脉冲宽度调制。

The presentpaper proposed one kind of numerical control single-phase inversionstructure, in detail elaborated the system parameter design, therectification work basic principle of work, the contravariant basicprinciple and the SPWM sine pulse width modulation.

本论文提出了一种数字控制的单相逆变器结构，详细论述了系统的参数设计，整流工作的基本工作原理，逆变的基本原理及SPWM正弦脉冲宽度调制。

The results show that there is a linear correlation between magnetic susceptibility and density. Take 1.6 g/cm^3 as a boundary value, the magnetism of high density coal and low density coal was opposite. The diamagnetism property of low density coal weakens and the paramagnetism of high density coal enhances along with the size reduction of fine coal. The magnetic field intensity influences the magnetism of coal.

研究表明：比磁化率同密度间存在线性相关关系，以1.6 g/立方公分为界，高、低密度级煤分别呈顺磁性和逆磁性，且随煤粉粒度的减小，低密度级煤的逆磁性减弱，而高密度级煤的顺磁性增强；磁场强度对煤的磁性有一定影响。

We can take Fourier transformation or Laplace transformation towards try to of square distance both ends according to the their lines property, differential calculus property and integral calculus property, its conversion for act for of elephant function square distance, from this algebra square the distance beg an elephant function, then take Fourier negative transformation or Laplace negative transformation have to originally square distance of solution.

我们可以根据他们的线性性质，微分性质和积分性质，对欲求的方程两端取Fourier变换或Laplace变换，将其转化为象函数的代理方程，由这个代数方程求出象函数，然后再取Fourier逆变换或Laplace逆变换就得出原来方程的解。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。