查询词典 alternating current

In this thesis the process of constructing the non-perturbative Hamiltonian theory is de-scribed and is applied to estimate the vacuum condensate. It contains the following contents:At the very beginning, by using the path integral method and eliminating the gluon freedom, aGCM action 〓 of current quarks including lower order current-current coupling was derivedfrom the QCD Lagrangian and the effective Hamiltonian operator that could hardly be doneby the normal methods was derived. After doing this, the broken vacuum is introduced whichincludes quark-antiquark condensate through the generalized Bogoliubov-Valatin transformation,the effective Hamiltonian of constituent quark was derived. The detailed formulas containingthe spatial current-current coupling term for the effective Hamiltonian and gap equations wasworked out by parameterizing the correlation kernel as a quadratic potential. And then, the gapequation was solved and the quark-antiquark condensate of vacuum was studied both in the casesof instantaneous interaction and retarded interaction. In the end, the effective Hamiltionian withtwo-body quark-quark interaction was derived with one-body approximation, and with the helpof the functional integral method the coupling non-linear dynamic equations for systems withnuclear matter was derived. Finally, these equations were solved by selfconsistent method andthe effect of nuclear matter on vacuum condensate was studied. The spatial current-current coupling term is too difficult to handle, hence the correlationkernel is assumed to be not important and usually omitted in the pure vacuum condensate, andthe instantaneous interaction generally is adopted. Retaining the spatial current-current termand partial retardation effect, the quark pairs condensate in pure vacuum was studied, and theeffect of quark mass was also studied. At present, little study is focused in the case with nuclearmatter and spatial current-current term also omitted. Under the approximation with partialspatial current-current term, the effect of nuclear matter on vacuum condensate was studied.

本论文描述了量子色动力学整体色对称模型哈密顿量方法的构建过程，得到了反映正反夸克对凝聚真空结构的关于组分夸克的有效哈密顿量算符，它隐含了胶子作用，并且准确至流-流耦合项；接着，通过参数化哈密顿量中的夸克作用关联核，导出平方禁闭势参数化选择的哈密顿量的具体公式和能隙方程；随后，应用公式，编程求解，考察了瞬时作用下和部分延迟作用下真空的正反夸克对凝聚，在计算中保留了空间流-流耦合作用；之后，导出瞬时势和延迟势下包含二体作用项的哈密顿量公式，并采用单体化近似，通过泛函变分方法得到核物质存在时耦合的非线性动力学方程；在保留部分空间双流耦合作用的近似下，求解核物质的动力学方程，考察核物质密度对真空凝聚的影响，以往考察真空凝聚，对关联核的选用，由于空间流-流耦合项不易处理，也认为作用不大，常忽略该项，并且常采用瞬时作用；本文保留空间双流项和部分延迟作用，考察了真空情形的夸克对凝聚，还考察了夸克质量对纯真空凝聚的影响，以往对核物质存在情形的真空凝聚考察很少，也都忽略空间流-流项，本文在考虑部分空间流-流项近似下，考察了核物质存在对真空凝聚的影响。

The welding of end ring of alternating current machine and the conducting bar is the key technology for manufacturing of asynchronous traction motor with high power. China South Locomotive and Rolling Stock Industry Corporation had taken this significative study as a key project for the manufacturing of alternating current machine. According to the welding of end ring of alternating current machine, the welding of copper and copper alloy is described in this paper. Results obtained in this study are as follows. 1.By the comparison of oxyacetylene gas brazing, induction brazing and resistance brazing, it was found that high-quality welding joint could be obtained by induction brazing, which also had the highest efficiency.

交流电机端环与导条的焊接是大功率异步牵引电动机制造的一项关键技术，开展其焊接工艺研究具有重要的意义，中国南车电机公司将此课题作为解决交流电机制造的一个重点项目，本文结合交流电机转子端环焊接的课题，对铜及其合金的焊接进行了研究，主要研究结论如下： 1、通过氧乙炔火焰钎焊、感应钎焊、电阻钎焊等焊接方法的对比试验发现感应钎焊可获得优质的焊接接头，且感应钎焊的焊接效率也是最高的。

Whole-cellpatch-clamp technology demonstrated that VDPG (1g/L) had notsignificant effects on the delayed-rectified K~+ current, TTX-sensitive Na~+ current and high-voltage-activated Ca~(2+) current of rat dorsalroot ganglion cells. The fast transiet K~+ current of cottonbollworm dorsal DUM cells, the fast transiet K~+ current, Na~+ current andhigh-voltage-activated Ca~(2+) current of Periplaneta Americana dorsalunpaired median cells were also not significantly affected byVDPG at the same concentration. However, VDPG had significant effecton the fast transiet K~+ current of Pieris rapae. The VES had not significanteffects on the high-voltage-activated and low-voltage-activated Ca~(2+)current of rat DRG cells.

膜片钳电生理实验显示1g／L毒囊粗毒对蜚蠊DUM神经元的快瞬时钾电流、钠电流、高电压激活的钙电流，对棉铃虫快瞬时钾电流和大鼠DRG细胞延迟整流钾电流、TTX-S型钠电流、高电压激活的钙电流均无明显作用，却对菜青虫快瞬时钾电流有明显作用；电刺激粗毒对大鼠DRG细胞低电压和高电压激活的钙通道无明显作用。

This paper investigates alternating iterative method and generalized alternating method for the solution of a large linear system, extend the convergence theorem and comparison theorem for generalized or alternating iterative method when the coefficient are Hermitian positive definite systems.

本文主要研究了大型线性方程组的交替迭代法及迭代法的各种变形，给出了当系数矩阵为Hermitian正定矩阵时各类迭代法的收敛原理及其相应的比较理论。

One of these testing methods, eddy current, has been widely used for metal thickness measuring because of its good sensitivity, high test speed , non-contact and other advantage. The principle of eddy current testing is that, when the test coil is close to the metal conductor with alternating current, the eddy current would be inducing in the conductor, and correspongdingly, the eddy current would affect the original magnetic field, the result is the coils impedance and inducing voltage changed.

其中涡流无损检测技术具有灵敏度高、检测速度快、非接触等特点而广泛应用于金属厚度检测，它的原理是当载有交变电流的检测线圈靠近金属导体时在导体中产生涡流，该涡流又影响原磁场，使得线圈的阻抗和感应电压发生变化，通过分析阻抗或感应电压的变化来获得被测导体的信息。

The socket structure is provided with a zero phase trigger control unit, through the photoelectric sensing element of the unit, optical coupling can be performed to generate zero phase trigger, and the opening or the closing of a two-way thyratron in the zero phase can be accurately controlled, therefore, an electric device inserted on an output socket can be started or stopped from the zero phase, in order to reduce the electromagnetic interference and prolong the service life of the electric device, the use efficiency of the electric device can be enhanced, the power supply thereof can be saved, filtering and rectifying can be performed through a current switching unit when the alternating current power supply passes through a filtering and rectifying circuit, the noise caused by external interference and affect can be filtered, and the power supply can be respectively transmitted to a current detecting socket and the input end of the current switching unit to be detected through a temperature sensor arranged on the current switching unit.

本实用新型为有关一种插座结构，尤指为设有零相位触发控制单元，可通过其光电感测元件来进行光耦合而产生零相位的触发，且可准确控制双向闸流阀在零相位的开启或者关闭，进而达到插置于输出插座上的电器装置从零相位开始启动或者关闭，以降低电磁干扰而延长电器装置使用寿命，且可提升电器装置的使用效率及节省电源，并通过电流转换单元于交流电源通过滤波整流电路进行滤波整流，可滤除外部所干扰影响的杂讯，并分别传送至电流侦测插座及电流转换单元的输入端，而可通过电流转换单元所设置的温度感应器来进行侦测，于电路温度升高时，温度感应器可进行切断双向闸流阀的电源输出而达到保护输出插座上所插设的电器设备。

Aluminium foil of different purity was etched by chemic and alternating current method in this dissertation,and we find that alternating current method excels.

本文采用不同纯度的铝箔，对其进行化学腐蚀和交流电腐蚀，结果发现铝箔的交流电腐蚀要优于化学腐蚀。

In Chapter 2,the polarization and loss mechanism of fruit in the alternating current arestudied,and dielectric parameters such as dielectric constant、equivalent impedance andequivalent capacitance are put forward to analyze the interaction between fruit internalquality and alternating current.

第二章 研究了水果生物介质在交变电场作用下的极化和损耗机制，提出了复介电常数、等效阻抗及等效电容几个相互联系又有所区别的电特性参数是研究交变电场与水果相互作用的基本参数。

The DC generator produces multiphase alternating currents in its armature windings, and a commutator on the armature shaft converts these alternating currents into a direct current output; or a homopolar generator produces a direct current without the need for a commutator.

直流发电机出示其骨架绕组多相交流电流和电枢轴上的一个换向器将这些交流电流转换成直流电流输出；或 homopolar 发电机一直流电流，而无需一换向器。

By the alternating direction implicit and current density recursive convolution technologies for the first time, a new current density recursive convolution alternating direction implicit finite-difference time-domain (CDRC-ADI-FDTD) formulation for collision unmagnetized plasma is presented.

首次把交替方向隐式技术与等离子体的电流密度递归卷积技术结合，给出了碰撞非磁化等离子体的CDRC-ADI-FDTD方法。

Don not attempt to do something which you can not to do.

不要企图做那些办不到的事情。

The expression of CTGF and TNF-αweredetected by immunochemistry and the number of Clara Cells was calculated.

光镜下观察肺组织的病理变化，采用免疫组化染色观察肺组织中结缔组织生长因子和肿瘤坏死因子-α的表达和Clara细胞的数量。