效率高的

It can be seen in the future, power electronics converter will get higher efficiency and power density.

可以预见软开关技术的应用可使电力电子变换器具有更高的效率和更高的功率密度。

CNC face milling and drill centres hole machine （Referred to as CNC milling fight machine ）,machine is mainly used for shaft parts batch and mass production, miling shaft at both ends 、 drilled the centers hole and turning one end of cylindrical axis, configured SIEMENS 802C CNC system , is controled by three axis, that is, the left X-axis spindle box movement, Y Right-axis spindle movement, Z-axis hydraulic self-centering jig up and down movement, according to the procedure to complete part of the auto-processing, processing of high precision and high efficiency.

数控铣端面钻中心孔机床，机床主要用于轴类零件成批和大批量生产，铣削轴的两端面钻中心孔并可套车轴一端的外圆，配置SIEMENS 802C数控系统，三轴控制，即X轴左主轴箱运动，Y轴右主轴运动，Z轴液压自定心夹具上下运动，按程序完成零件的自动加工，加工精度高、效率高。

As the complete characteristic curves of reversible pump turbine are often used to calculate the instantaneous parameters, this paper studies the characteristic curve and the wicket closure and opening law in pumped storage plants.Chapter 1 presents the importance and the necessity of this study and reviews the previous related research on hydraulic transient process and valve regulation in pumped storage plants.Chapter 2 analyzes the six collected characteristic curves of reversible pumped turbine and studies their diversification from the point of view of specific speed. The six collected discharge and moment curves with maximum efficiency have been fitted to piecewise continuous curves. This curve-fitting procedure is listed.Chapter 3 takes Liyang Pumped storage plant as an example and analyzes the effect of different characteristic curves on regulation guarantee parameters and the variety of its trochoid during the same operation status.Chapter 4 takes three pumped storage plants with different heads as examples and studies the characteristic of coordinated closure with wicket gate and ball valve and its effect on dynamic pressure in the spiral case, inlet pressure in the draft tube and the rise of rotating speed.Chapter 5 summarizes this paper and point out what should be done in the future research.

由于在过渡过程分析计算中，需要频繁利用可逆式机组的全特性曲线推求机组的瞬时参数，所以本文就特性曲线及关闭规律问题进行了研究，其主要内容如下：第1章，指出本文研究的意义和目的，回顾前人对水力过渡过程、抽水蓄能电站及阀调节的研究成果，在此基础上提出本文的研究内容；第2章，针对收集到的六套特性曲线，从比转速的角度出发来研究可逆式机组特性曲线的变化规律；并对六套曲线的最高效率流量和力矩曲线进行分段拟合，得到各分段函数的具体形式，再通过举例说明最高效率曲线的拟合步骤；第3章，以溧阳抽水蓄能电站为实例，分析讨论不同比转速特性曲线对调保参数造成的影响及对于相同工况其轨迹线的变化；第4章，结合高、中、低三水头段抽水蓄能电站，在导叶直线关闭的基础上，研究导叶与球阀协联关闭规律的特点及对蜗壳动水压力、尾水管进口压力及转速上升造成的影响；第5章，总结全文，提出今后研究的重点和方向。

The product is a well balanced cleaner and maintainer based on hard waxes and solvents. It cleans while maintains and protects floors and buffable protective film.

本产品是一种硬蜡和溶剂含量都很高的清洁保养产品，兼备清洁和保养的双重功效，清洁效率高，并具有持久的保养作用。

The alloy film anode showed high charge-discharge capacity and columbic efficiency, and good cyclic stability.

合金薄膜电极具有较高的充放电容量、良好的循环性能和非常高的充放电效率。

Taking a example for verilying the feasibility and computation precision of the approach,the computation results show that the PSO-based approach is a useful tool for solving such nonlinear optimization problems as cylindricity evaluation with complicated goal function and more parameters. It is superior to that given by the Least Square Method and a little better than or equal to those given by GA-based method and another Minimum Zone Method.

计算结果表明，该方法对于圆柱度误差评定这类具有复杂目标函数和较多参数的非线性优化问题有很好的计算性能，优于最小二乘法；与遗传算法和其它满足最小区域条件计算方法相比，计算精度略优于前者或者与前者相当，能够获得精度较高的结果，而突出优点是简单，易于实现而且计算效率较高。

For the first time, a screw pile and pile driver system for preventing flood and rushing to deal with an emergency was manufactured. The screw piles of the system is different from screw drills used to sap, and it doesn't push soils out. Analyses, including the screw pile's structural strength analysis and the screw blade's welding analysis, were done by ANSYS, which showed that the screw pile's structural strength is enough and that the distort of the screw blade is small. Testing on the screw pile and pile driver system showed that the system performed stably and could meet the need of preventing flood and rushing to deal with an emergency. A mechanics model of interaction of a screw pile and soil was built, and expressions of torque of screw pile's cylindrical part on the condition of screw pile's crew part being driven into soil fully were gained, then the relation of the torque with screw pitch and out diameter of cylinder, which shows the torque decreases with the screw pitch increasing, and that the torque increases with the out diameter of cylinder increasing, which was according with the experiments of the screw pile's being driven into soils, and thus a screw pile with the best structure was chosen. Experiments of bionic surface showed that, on the condition of certain pressure on the surface, the protruding bionic surface can not reduce adhesion and resistance and that the corrugated bionic surface can reduce adhesion and resistance. An orthogonal experiment of the corrugated bionic surface was done with the factors including the width of protrusion, the space between two protrusions, the trolley's velocity and the vertical surface pressure and with the surface frictional coefficient as the experimental target, and some inclusions were drawn that the best combination of the factors was acquired and that the width of protrusion affected the surface frictional coefficient remarkably.

研制了防汛抢险螺旋桩机系统，提高了沉桩作业效率；利用ANSYS对桩体进行整体结构强度分析以及螺旋叶片的焊接分析，表明桩体结构强度足够，焊接过程中，螺旋叶片的变形小；对整个螺旋桩机系统进行试验，表明该系统性能可靠，工作稳定，作业效率高，能够满足防汛抢险沉桩作业基本需要；建立了螺旋桩桩土作用力学模型，得出螺旋桩沉桩过程中螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩以及扭矩与防汛抢险螺旋桩的螺旋导程和圆柱外径的关系曲线，表明螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩随着螺旋导程的增大而减小，随着圆柱外径的增大而增大，这与螺旋桩沉桩试验结论相符合，据此优选出最佳结构的螺旋桩；仿生曲面试验表明，尺寸较小的球冠突起型仿生曲面在一定压力作用下未能起到减粘降阻的作用，而尺寸较大的波纹型仿生曲面相对平板具有一定的减粘降阻作用；以波纹型仿生曲面突起宽度、波纹型仿生曲面两突起之间间距、台车的牵引速度以及叶片表面垂直载荷为因素，以曲面摩擦系数试验指标进行正交试验，寻求出在一定试验条件下最佳因素水平组合；波纹型仿生曲面突起宽度在本试验条件下对曲面摩擦系数影响显著，而其它几个因素对曲面摩擦系数影响均不显著；通过波纹型仿生曲面突起宽度和台车牵引速度的单因素试验，表明曲面摩擦系数随着仿生曲面突起宽度的增大而减小，而随着台车牵引速度的变化基本保持不变，和正交试验结果保持一致。

High precision: Advanced testing instrument,together with the entire manufacturing techniques combining the latest fully automatic wire-stretching machines,continuous annealing lines,molds and lubricants,guarantees precision,1000N/m strength,wire diameter tolerance within /-0.001mm,good vertical exceeding 98% good surface quality,high precision,high efficiency and non-sticking.

精度好：先进的检测设备，加上全部采用目前国外最先进的全自动伸线机、连续退火生产线、模具、润滑剂到全套生产工艺。从而确保精度、强度可以达到1000N/m ，线径公差控制在？0.001mm 以内，垂直度好，可以达到98%以上，广泛适用於各国不同型号的慢走丝切割机床。表面质量好，精度高，可以达到效率高，不返粘效果。

Not only in low or wide temperature condition but also in higher temperature, Pt-Rh/Ce-Zr-Sr/Al_2O_3 can show high specific surface area raio and excellent stability. It is considered as the best catalyst, which has a promising industry application prospects.

和Sr含量为3 wt。%时，其催化活性达到最高，实现了在较低的温度和较宽的温度窗口具有较高的催化活性NO_x转化效率达到53%在高温条件下也显示了高比表面积和高稳定性。

Results showed that pepper yield and water use efficiency are highest, and leaf area index and plant height are similar for the treatment with a potential threshold of -30 kPa as compared to other treatments.

试验结果表明，以－30kPa为灌水下限的处理具有较高的叶面积指数、株高、最高的辣椒产量和水分利用效率。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。