变变

People's attitudes about what is most important in life come and go.

对于什么是生活中最重要的东西，人们的想法变来变去。

Through analyzing report forms format of IEC 60 870-5104 stipulation,as well as considering computer monitoring system of 330kV Dashimen and Jingyang substation and experiences of provincial dispatching system,the paper studies some command flow,and provides technical safeguard for provincial dispatching automation system adopting network stipulations transmission process.

通过分析IEC 60 870-5-104规约的报文格式，借鉴330 kV景阳变、大石门变计算机监控系统和省调自动化系统的联调经验，研究了规约的各种命令流程，为省调自动化系统采用网络规约传输提供了技术保障，同时也极大地丰富了调度自动化系统的应用范围。

In this paper, an improved inverter side passive filter was proposed on the bases of analysis of common-mode and differential-mode voltage, and a detailed design procedure of parameters was given.

本文通过对PWM逆变器驱动电机系统产生的共模以及差模电压分析，提出了一种改进型的逆变器端无源滤波器，并给出了参数的设计方法。

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。

An important problem of calculus of variations used in constrained differential systems, i.e., the commutation relation of differential operator and variational oprerator, is investigated by means of Frobenius theorem of integrability.

利用Frobenius可积性定理，研究微分约束系统一个重要的变分法问题：微分运算与变分运算的对易关系。

Using absorbed value feature of known mineral criterion for reference, utilizing Landsat 7 ETM remote images and features of altered mineral spectrum from USGS, valuable alteration mineralization information are extracted by comparison of spectrum similarity.

利用该区域的Landsat7 ETM遥感影像和标准光谱库中的特征蚀变矿物光谱为基本数据，借鉴已知矿物标准中的吸收谷特征，应用光谱特征匹配技术进行吸收谷谱区间和吸收谷深度对比，通过比较两者的相似性，达到提取蚀度矿物的目的，提取出许多有价值的似蚀变带遥感信息。

Comparison between the model and test results shows that the proposed rheological model is reasonable.

将流变模型曲线和试验结果进行比较，结果表明该模型能够较好地描述不同法向应力和剪切应力作用下节理蠕变的变形规律。

A calculation model of stress field of the composite plate with circular holes was built according to the theory of complex variable function.

根据复变函数理论建立了计算模型。采用仿射变换的方法得到了准确描述应力场的复变应力函数。

The analysis of molecular variance revealed that 93.85% of the variance component was attributable to the variation among individuals within ditches. Low levels of the genetic differentiation coefficient among ditches, G=0.172 and Nm=2.4, indicated that the ditches barely hinder gene flow between Scaevola populations. UPGMA cluster analysis and principal coordinate analysis revealed no major groupings among ditches or among plants.

经过分子变方分析显示海南草海桐有93.85％的变方成分存在於个体间；POPGENE分析结果显示其遗传分化系数G(下标 ST为0.172，而基因流为2.4，显示沟渠并无阻碍基因交流之能力；UPGMA归群分析及主座标分析结果显示海南草海桐个体间几乎无差别或差异很小。

The cognitive/conation variables explained about 54% of the overall variance of learning performance.

2认知╱意动成份八个变项可以联合解释国中生学习表现总变异量的54%，其中内容知识是学习表现最有力的预测变项。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。