换相

LES cooperated with the second order full extension ETG finite element method is applied to simulate three typical problems concerned with convection heat transfer with sufficient experimental data. By comparing the numerical results with the experimental results, LES is proved to be of better accuracy and stability when it is used to solve the problems concerned with convection heat transfer. The time history of the flow field and temperature field can be reflected better, and abundant information of the fields can be obtained. Furthermore the details of the change in the vortex structure can be captured.

应用大涡模拟与二阶全展开ETG有限元离散格式相结合的方法对具有实验基础的三个典型对流换热问题进行了数值模拟，并将模拟结果与相应的实验结果进行对比，证明了大涡模拟应用于对流换热问题中具有较高的稳定性和精度，能够较好地反映流场和温度场的时变过程，提供丰富的温度场和流场信息，捕捉流场中旋涡结构的变化细节，尤其适合于边界形状复杂的区段内含有大尺度各向异性涡的流动和换热问题的计算。

As a new technique in the field of microchannel phase-change heat transfer , micro capillary grooved heat sink can drive fluid flow by capillary force and creat enhanced evaporation heat transfer conditions by promoting the formation of an extended meniscus in the three-phase contact-line region of a microgroove.

作为一种新兴的微通道相变换热技术，毛细微槽群蒸发热沉由于能依靠毛细力驱动液体流动，并易于在微槽内三相接触线区域促进扩展弯月面薄液膜的形成，创造高强度的蒸发换热条件，因而能够被用来实现极高换热系数和热流密度的换热过程。

This new type heat pipe was applied in a puddling process. The waste flue gas from the hot blast stove was used as the hot source to heat the cold mixture of compressed air and coal powder. The observed practical performance of the heat pipe showed a good agreement with the design expectation, which verified feasibility of using the separated type heat pipe for the heat transfer of the solid powder.

这种新型的分离式热管换热器应用于一个固相粉末换热系统——利用高炉热风炉的废烟气加热高炉喷煤用的空气和煤粉的混合物，实际运行工况与设计结果具有良好的一致性，可见利用套管结构的分离式热管作为以固相粉末为换热介质时的传热元件是完全可行的。

And, theoretical and experimental studies have been carried out of the performance of the heat transfer enhancement by adding a proper amount of nanoparticles to the thermosiphon with water as the working fluid. Compared with the ordinary thermosiphon, results indicate that this heat pipes posses such advantages as good startup, lower tube wall temperature, and its heat transfer coefficient is increased by 47～96%, heat flux is increased by 7.6～15% in the range of the experiment. The performance of the heat transfer relates to the diameter and the volume fraction of nanoparticle.

理论和实验的研究了这种热虹吸管蒸发段的工作特性，结果表明，与普通热管相比较，这种新式热管具有很好的启动特性，低的管壁温度，换热系数提高了47～96％，轴相热流率提高了7.6～15％，其换热性能随纳米颗粒粒径的减小而增大，随纳米颗粒加入量有所增加，当超过一定量时换热性能反而降低了。

By the war outbreak, only 20 to 24 cannons were mounted in the first series of rearmed TKS. There were also plans to rearm TK tankettes with cannons, what demanded adding a front superstructure, making it similar to the TKS.

也曾计划为TK换装火炮，要求增加一个前部superstructure和TKS相类似。1939年8月25日计划为16辆TK换装，但是并不确定在战争爆发之前完全这个换装工作。

The phase conversion process has been discussed on the basis of three working ways of inductance loading in TEM-Ⅱtransmitter, and then several problems have been put forward.

分析了IGBT全桥变换电路实现功率变换时感性负载上电压、电流的瞬态变化规律及无功功率的释放回路，对TEM-Ⅱ型瞬变电磁法发射机阻感性负载三种工作方式的换相过程作了深入全面的讨论，进而提出几点注意事项。

The pressure adjusting valve 1, piston 2, moves up to close the contact of micro-switch 5

电器面板显示，在这样的压力下完成了倒线。对于安装有电控换相起的双线系统，微动开关5

Brushless DC motor driver for the use of six-phase control procedures, can be used for six three-phase full-bridge driver circuit of brushless DC motor control.

详细说明：无刷直流电机驱动程序，采用六段换相控制程序，可用于六管三相全桥驱动电路的无刷直流电机控制。

A new kind of frequency-converting timing system of short phase-shifting current mode circuit was introduced in view of the defects of inverse circuit of series-wound diode current mode,which is widely adopted in frequency-converting timing systems.

针对应用较为广泛的串联二极管式电流型逆变电路变频调速系统存在的缺点，提出了一种新型的短路换相式电流型逆变电路。

A new algorithm is proposed using wavelet transform and Hilbert transform to calculate the reactive power.

提出了正交小波变换和希尔伯特变换相结合的无功功率测量算法。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐