气藏精细描述技术在苏里格气田的应用

由于苏里格气田储层分布的高度复杂性,目前对气层分布预测基本上以定性预测为主,还不能做到真正意义的定量预测。现有的地震预测技术在苏里格气田复杂地质背景和地球物理条件下存在多解性,其原因主要是地震资料的分辨率和保真度问题、砂岩储层与围岩波阻抗关系的不确定性和叠后反演预测方法的局限性,因此,需要用科学的思路来对目的层进行更为精细的描述及预测,对气藏产能、储能做客观实际的评价,密切指导下一步的开发。     

磁电机轴套加工工艺探讨

本文对磁电机轴套的精铸成形加工工艺和摆辗成形加工工艺进行了分析,通过这两种工艺可以达到提高材料利用率,减少切削加工的目的.这两种加工技术生产效率更高,加工表面质量好,性价比高,符合现代绿色加工的发展趋势.     

铁摩辛柯梁压弯问题的新求解体系

采用两个独立的广义位移v(z),θ(z),引入对偶变量,建立了铁摩辛柯梁压弯问题的哈密顿对偶求解体系,采用了多变量一阶常微分方程组(哈密顿对偶方程)来描述问题,指出由于方程组具有辛结构的形式,能方便的求出解析解或用精细积分法求出高精度数值解,为求解问题提供了新的思路。     

糯扎渡高心墙堆石坝离心模拟试验研究

近年来，随着高土石坝建设的迅速发展，研究坝体在施工期和运行期的各种性状已成为土石坝研究领域中最为重要的课题。同时，离心模拟试验技术在高土石坝的研究中也有了更加广泛的应用。本文结合坝高261．50m的糯扎渡心墙堆石坝，利用小比尺离心模型进行了模拟试验，研究坝体在施工期和运行期的应力和变形性状，论证采用小比尺离心模型研究高坝变形和应力性状的可行性，同时提出了原型坝体在竣工期和蓄水期的应力变化和变形情况，为该坝的设计和施工提供了科学依据。     

基于细节分量提取的脉压雷达信号检测技术

小波分解可以将信号分解为多层近似分量与细节分量，脉压雷达信号的脉内信息可以在细节分量中得到很好的体现，因此小波变换方法对脉压信号有着很大的优势。Mallat快速算法使小波变换走向工程实用成为可能，对ADC输出的数据流做小波分解，得到各层的细节分量，找到波形失真较小并且能够反映脉内特征的细节分量作为新的数据源，对之进行相关处理，完成信号检测。文章最后以实际雷达信号为对象进行了实验，实验结果表明该方法是切实可行的．     

电流滞环控制PWM逆变器异步电动机的非线性解耦控制系统

本文针对电流滞环控制PWM逆变器异步电动机系统这一非线性、多变量、强耦合的控 制对象,采用非线性变换和非线性反馈,实现了系统的动态解耦和全局线性化.其中关键问 题是对合性条件的满足,从而分解成线性化的转速子系统和转子磁链子系统,两个子系统的 调节器可按古典线性理论设计.最后,用8096十六位单片机实现非线性解耦控制算法,组成 了交流变频调速系统,并给出实验结果.     

Approximate linearization of nonlinear control systems

The paper address the problem of approximate linearization of a nonlinear control system by state feedback or dynamic feedback. The main result proved is that if the fast k d-relative degrees are equal to each other, then the input-output response of a nonlinear control system can be linearized to degree k. Any system having linear d-relative degree can be linearized to any degree by dynamic feedbacks. One example of signal tracking using dynamic feedback linearization method to improve the performance is also given.     

Sequential statistical design strategy in a kinetic study of propylene oxidation

A sequential design strategy was used to direct an experimental kinetic study of propylene oxidation over bismuth molybdate. Two statistical criteria were used to design experiments. The first is a joint criterion for the dual problem of model discrimination and parameter estimation which was proposed by Hill et al. (1968), but which to the best of our knowledge has not been tested in an experimental program. Using this joint criterion design, it was demonstrated that both the objectives of model discrimination and precise parameter estimation were effectively accomplished. After model discrimination had been achieved, a design strategy for further improvement in parameter precision was found, as expected, to be effective for that purpose.     

Universal nonsingular controls

In this note we prove that, for analytical systems satisfying the strong accessibility rank condition, generic inputs produce trajectories along which the linearized system is controllable. Applications to the steering of systems without drift are briefly mentioned.