无特性的

The subsynchronous oscillation characteristics of a synchronous machine connected to a static VAR compensator is studied with the complex torque coefficient method realized by time domain simulation, and some important conclusions are obtained which can guide the design and operation of SVCs to avoid SSO problem.

4基于时域仿真实现的复转矩系数法，对与静止无功补偿器SVC相联接的同步发电机组的次同步振荡特性进行了深入的研究，得出了一些重要结论，可为SVC的设计和运行提供避免SSO的依据。

Solid carbide tungsten fishtail drill is suitable for pcb flexible foil clad laminate,used for target machine drilling,the features of pcb fishtail drill are thin and flexible plate,it's structure and cutting methods are different with normal pcb drill bits.its two main cutting edge is concave and formed 100degree angle,in order to distinguish with PCB drill,named fishtail drill.fishtail drill cuts beginning of circular drill.concave along the main cutting edge to cut,chip is just two much fine filament.cuttingis falling off naturally,in order to be processed without burrformation by pcb surface.

整体硬质合金鱼尾钻适合印制电路板行业加工挠性覆箔板，为打靶机钻孔用。鱼尾钻所加工的印制电路板特性是薄板、带柔性、这样就决定了它的结构和切削方式与一般PCB钻不一样，它的两主切削刃是内凹的，两主切削刃形成100度的夹角，为了与PCB钻区别，就叫它鱼尾名。鱼尾钻切削时从我圆处钻尖开始，沿着内凹的主切削刃切削，切屑只是两条极细丝状切削，整个切削自然剥落，从而被加工印制板表面平整无毛刺。

Then, the necessary conditions for testing non-redundancy and predigestion and the analysis of loseless decomposability are discussed.

给出了与或图数据库的定义、规范化理论、无冗余和既约化理论，证明了它与关系数据库的等价性；然后给出了依赖集存在冗余和既约的必要条件，讨论了无损分解在与或图形式下的特性，从而形成了与或图数据库关系模式分解的规范化算法。

The revisionism within our Party was characterized by long-standing features of revisionism in the communist movement that Lenin had also exposed—which were embodied in the notion that "the movement is everything, the final aim is nothing," and the determinist orientation that what is necessary is what is possible, and what is possible is what is already being done.

187；我们党内的修正主义体现的正是共产主义运动中长期存在的修正主义特性，这一点已经被列宁揭示——它体现在这样一种概念上："运动本身就是一切，并无最终目的"，一切都被决定，必需的便是可能的，可能的便是业已做过的。

In the present paper,the goal applies in the development in the mixed style battery cocurrent of motor driver design in the electrically operated bicycle,the use lead-acid battery and the LiFePO4 battery takes the main actuation power to originate,the iron phosphate lithium battery has the life to be long,the electric discharge power is big and the transformation power suits the high electric current product good the characteristic;The lead-acid battery is in a market condition the quite mature battery product has the high security in the thermostable characteristic,and designs a driving circuit to actuate the cocurrent to have brushes the motor to lead the bicycle advance,comes in the enfilade non-ascent road section use LiFePO4 battery as the actuation electric power to originate,in had the ascent road section use lead-acid battery to come as the actuation electric power to originate, has promoted bicycle's endurance and reduces accumulator cell's energy loss.

本论文中，目的在研制应用於混合式电池於电动自行车之直流马达驱动器设计，使用铅酸电池与磷酸铁锂电池来作为主要驱动动力来源，磷酸铁锂电池具有寿命长、放电功率大及转换功率佳适合高电流产品的特点；铅酸电池为一市面上相当成熟的电池产品具有高度的安全性於耐高温的特性，并设计一驱动电路来驱动直流有刷马达来带动自行车前进，於直路无斜度路段使用磷酸铁锂电池来作为驱动电力来源，於有斜度路段使用铅酸电池来作为驱动电力来源，提升了自行车的续航力和降低蓄电池的能量损耗。

In this paper the effects of scanning truncation error, scanning position error, random amplitude and phase error, and multiple-reflection error in near-field antenna measurement are analyzed; error equations and the uncertainty of measurement are obtained through computer simulation; compensated techniques for reducing the effects of measurement errors in near-field antenna measurement are presented and the formula and arithmetic of phaseless near-field techniques are derived.

本文从解析法和数值仿真两个角度深入分析口面天线近场测量中扫描面截断误差、扫描面位置误差、随机幅相误差、多次反射误差等误差源对天线远场特性测量精度的影响，一方面从理论上给出相应的误差方程，另一方面建立误差分析模型，通过计算机模拟，得到不同误差条件下测量结果的不确定度，并介绍了减小这些误差的修正方法，推导无相位近场测量的公式和算法。

The merit of the invention are: 1 adopting free curved surface imaging method , three part reflection type Zernike polynomial free curved surface forms short focal distance bigger, relative apertures bigger fields of view angle imaging , rectifying optical aberration much better and its structure is simple; 2 adopting the reflection structure without optical lens, has removed the effect of various chromatic aberration , guarantee the imaging articulation; 3 adopt the design of short focal distance big fields of view angle, focal distance 8 - 15 mm, field of view angles 100 -135 degree, having 120 times multiplications under 250 mm imaging distance, having ultra-thin characteristic property; 4 adopting big relative apertures design ,the relative aperture is 2.0-2.4, having improved the illuminance of flat surface; 5 adopting image space telecentric imaging method , ensures that the image surface irradiance is homogeneous.

本发明的优点是：1采用自由曲面成像方法，三片反射式Zernike多项式自由曲面形成短焦距大相对孔径大视场角成像，更好地校正像差，结构简单；2采用无透镜形式的反射式结构，消除了各种色差影响，保证成像清晰度；3采用短焦距大视场角设计，焦距8～15mm，具有100～135度的视场角，在250mm成像距离下有120倍的放大倍数，具有超薄特性；4采用大相对孔径设计，相对孔径为2.0～2.4，提高像平面上的光照度；5采用像方远心成像方法，保证像面辐照度均匀。

There,however,lacks of a generalization of the characteristics of off-axis aberration of non-imaging focusing heliostat as a whole among the different designs and thus the optimization for the different purposes of application.

然而，无光像聚光定日镜的发展还欠缺一份对其偏轴像差的特性进行综合和归纳的工作以利于根据应用的技术要求进行优化，这是对发扬这种新型定日镜的重要的基础工作。

To isolate forebrain and hindbrain of human fetuses about 9 weeks and 12 weeks from spontaneous abortion. Neural stem cells were cultured in special culture medium and were compared with growth characterization.The differentiation from these neural stem cells was investigated in both a fetal bovine serum-containing and a non-supplemented,serum-free basal medium.

材料与方法：利用神经干细胞的条件培养基，对从9周和12周胚龄的自然流产胎儿分离的前脑、后脑进行神经干细胞培养，比较其生长特性，并分别观察在无生长因子的基础培养基以及含有胎牛血清的培养基中神经干细胞的分化情况。

It is shown that the decrease of reliability is evident when longitudinal probability distributions of cross sections of unbonded prestress tendons are considered, and the index of reliability is reduced with the increase of the number of independent and identically distributed random variables.

结果表明，考虑无粘结预应力筋截面积沿长度方向的分布特性而引起的可靠指标的降低比较明显，可靠指标随着独立同分布随机变量的数目的增大而减小。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了