谐振

The permittivities of N, N-dimethylformamide, water (H2O), and DMF-H2O mixture solution were measured by a resonant cavity perturbation method at 2.45 GHz and 288, 298, and 313 K. The measured results showed a specific phenomenon wherein the imaginary part of the solution's permittivity was larger than that of each of the components.

在288、298和313K三个温度和2.45GHz频率下利用微扰谐振腔法测量N，N-二甲基甲酰胺、水(H2O)及其混合溶液的等效介电常数过程中，发现了混合溶液介电损耗虚部大于其中任一组分的介电损耗虚部的特异现象。

This resonator consists of only three operational amplifiers,and provides a pules train of the switching signal to control static switch on or off with adjustable frequency f and conduction duty k.

这种谐振器仅由三个运算放大器组成，能产生开关信号脉冲列来控制静态开关的导通和关断，其频率f和导通占空比k可调。

Through theoretic reckoning and simulating analyzing, several control strategies for shunt APF were compared and chose ip-iq arithmetic ofthe instantaneous reactive power theory control strategy as the right scheme to produce the instructing current. Based on it, some new control arithmetic was subjoined to suppress the resonance in system and balance the dc side capacitor voltage. Two topologies of main circuit were compared and chose the three-phase voltage-source converter with a split-capacitor as its main circuit structure. The numerical scales of the dc side capacitor and inductance of reactors were calculated. The high-pass filters were designed to eliminate effectively the highfrequency harmonics produced by APF.

通过理论计算和仿真分析，比较了并联型APF的几种控制策略的优点和缺点，从中选择瞬时无功理论控制策略i_p-i_q计算方式为指令电流产生的算法，并在此基础上增加了抑制系统谐振和平衡直流侧电容电压的控制；比较了并联型APF主电路的两种常见形式，从中选择了三相电压型变流器的主电路形式；算出适合该APF的直流侧电容和出线电感的参数；设计出能有效消除APF产生的高次谐波的高通滤波器。

The edge-effect was investigated and an analytical model developed.With which Q of some available laterally-driven microresonators has been calculated.The result is compared to that taints by the present model.

论文考虑了边缘效应的影响，建立了一个分析模型，对已知的几种横向振动谐振器的 Q值进行了计算，并将其与实测值比较。

The method is based on the principle of automatic frequency tunning, i.e.

所用的方法基于自动频率微调的原理，即利用一套鉴频系统使反射速调管的振荡频率自动地跟踪到被测腔的谐振频率。

The pod was tested again and the results indicate that the resonance frequency and amplification factor meet the requirement.

重新进行试验后，结果表明系统谐振频率和放大率都满足要求。

Based on the above theories, some vibration characteristics of longitudinal acoustic horns are analyzed with finite element analysis software ANSYS. Some factors influence to large end amplitude distribution is studied such as big end diameter, length of horn, and diameter ratio of big end to small one. In addition, we carry on analysis and research to resonance frequency of large cross-section acoustic horn, amplitude magnification factor, wave node position of horn, transverse vibration situation and so on, and some related change rules are obtained.

在此基础上，通过有限元分析软件ANSYS对纵向超声变幅杆进行了振动特性分析，研究了变幅杆的大端直径、变幅杆长度、大小端面直径比对大端面振幅分布的影响，并对大截面变幅杆的谐振频率、振幅放大系数、变幅杆的波节点位置，横向振动分布等进行了分析研究，总结了相关的变化规律。

Propose new DRA antenna designs and equivalent circuit model.

研究了介质谐振器天线分析与宽带化设计技术。

The capacitance of the capacitor is determined on the basis of the antenna inductance, the frequency of communication and the law of resonance whereto a chip ( 3 ) connected to said antenna ( 4 ) is subjected.

电容器的电容根据天线的电感、通信频率、所述天线(4)与芯片(3)必须符合的谐振规则而确定。

P.41: The physical dimension of the antenna determines the amount of inductance of capacity existing in the circuit and consequently the resonant frequency of the antenna system.

天线尺寸决定回路中的电感量和电容量，从而也决定天线系统的谐振频率。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。