真空的

The item adopts many high and new-technologi es , include extract from innocuous solvent, vacuum concentrated, accumulate by membrane, separate by macroporous adsorptive resins, recrystallization, vacuum or spray drying etc, it can extract refined radices puerarire starch, radices puerarire isoflavone and radices puerarire element from puerarire.

项目采用无毒溶剂提取，真空浓缩、膜富集、大孔吸附树脂分离、重结晶精制、真空或喷雾干燥等高新技术组合的新工艺，从葛根中综合提取葛根淀粉、葛根异黄酮及葛根素。

But in practical operating, overvoltage caused by reignition of the vacuum switching device frequently appears, and it result in damage of the capacitor bank or the switchgear itself. Ensuring the switchgear against reignition and installing a protective device are two main approaches to avoid the phenomenon. In this paper, a study on overvoltage caused by reignition due to capacitor bank switching with the vacuum switching device and its preventive measures are carried out. The main work which has been done and researches are as follows: 1. The producing mechanism of overvoltage and its influence factor are analyzed. It is pointed out that single-phase reignition is the main reason for damage of the switchgear and two-phase reignition is the main reason for damage of the capacitor bank,so overvoltage of single-phase reignition and two-phase reignition are the emphases of prevention. 2. Analysis of the special working condition of the operating switch for capacitor bank is carried out. It indicates that the vacuum switching device is difficult to realize no-reignition under this operation condition, so it is more practical to adopt protection devices. 3. Analyses of protection effect of RC and MOA and their shortages are carried out. It shows that the two methods can only restrain effectively overvoltage caused by single-phase reignition, and they cannot protect the capacitor bank when reignition of two-phase occurs. 4. The operation principle of G-R damping device is analyzed and discussed emphatically.

本文针对真空开关投切电容器组时因重燃而产生的过电压及其防治措施进行了研究，所开展的主要工作和研究结果如下： 1、对过电压的产生机理及其影响因素进行了分析，指出单相重燃是导致开关设备损坏的主要原因，而两相重燃则是导致电容器组损坏的主要原因，因此单相重燃和两相重燃过电压是防护的重点； 2、对电容器组操作开关的特殊运行条件进行了分析，指出在这种运行条件真空开关难于实现不重燃，因此采用保护装置更具有现实意义； 3、对RC与MOA的保护效果和存在的不足进行了分析，指出这两种方法均只能有效抑制单相重燃过电压，而不能在发生两相重燃时保护电容器组； 4、重点对G-R阻尼装置的工作原理进行了分析和讨论，指出该装置接入后线路中将会出现两种频率的高频振荡，而电容器组上的过电压是由这两种振荡共同决定的； 5、根据对上述两种振荡的分析指出存在一个最佳电阻值使得过电压最低，并提出了电容器组电压和最佳电阻值的近似求解方法； 6、使用电气暂态分析软件MATLAB对G-R装置的保护效果进行了仿真计算，证实该装置确实可以有效抑制重燃时的电容器组过电压； 7、根据仿真与近似计算结果的偏差提出了近似计算的修正方法，经过修正后的过电压计算结果与仿真结果吻合较好； 8、对G-R装置中放电装置G与阻尼电阻R的要求进行了分析，指出采用编织电阻和真空间隙可能是最佳选择。

It is prepared by the steps: using vacuum machine set to vacuumize the reaction chamber, then charging protective gas to generate electric arc between moving electrode and metal Pb, and quickly condenses Pb steam to deposit Pb powder in powder collector.

本发明所述的铅粉按以下步骤制得，用真空机组对反应室抽真空，再充入保护气体，在运动电极与金属铅之间产生电弧，对铅蒸气快速冷凝，沉降至收粉器中。

A change in single-screw pump suction valve opening degree, when the suction vacuum is small, pump parameters changed little, and when the suction vacuum is larger, the pump working conditions deteriorated dramatically.

改变单螺杆泵吸入口阀门开启度，当吸入口真空度较小时，泵特性参数变化不大，而当吸入口真空度较大时，泵的工作状况急剧恶化。

The product qualities of vacuum belt drying and freeze-drying are better than that of air-drying.

真空冷冻干燥、真空带式干燥的产品品质优于热风干燥。

Orthogonal experiment was adopted to analyze the effects of vacuum casting processing parameters such as mould temperature,resin temperature,vacuum deaerating time and curing temperature etc.

采用正交实验方法进行实验，研究了微齿轮真空铸型过程中模具温度、树脂温度、真空脱泡时间和固化温度对微齿轮外形尺寸的影响作用。

Provides the theoretical data for the vacuum degassing purification and vacuum dry of liquid medium.

为液体介质的真空脱气净化和真空干燥提供了理论数据。

VS-600 external –pump vacuum machine Uses Japan and Korea leading technology collection vacuum,Seal,Gasifies the many kinds of functions in a body, The sealer uses the barometric pressure type, Thorough change tradition packing sealer not firm phenomenon.

vs-600 外抽式真空包装机采用日韩领先技术集真空，封口，充气多种功能于一体，封口采用气压式，彻底改变传统包装封口不牢的现象。

Installation of retrofits is allowed by Seiler Vakuumtechnik GmbH only or with written authorization by Seiler Vakuumtechnik GmbH.

对设备的翻新只能由赛乐真空技术有限公司或经赛乐真空技术有限公司书面授权才可以进行。

This system which can do correlation analysis among vacuum arc imagine, light intensity spectrum density, electron density, vacuum arc voltage, vacuum arc current has a series of properties like synchronous exposure, high sampling speed, good quality with comparatively low price, strong functional software, friendly user's interface and so on.

本课题研制成功了真空电弧动态图象高速微机采集系统，该系统具有同步曝光、采样速度快，性能价格比高，软件功能强，用户界面好等特点，该系统可对瞬时的真空电弧形态，光强密度，电子密度，电弧电压，电弧电流进行相关分析。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。