谐振器

Compared with conventional half-bridge topology, a branch comprising an auxiliary switch and a capacity is added in secondary circuit.

与传统的不对称半桥变换器相比，该变换器在变压器的副边电路中增加了一条由辅助开关管与谐振电容串联组成的辅助支路。

A new ZVS-ZCS ARCPI (auxiliary resonant- commutated pole inverter) is proposed to solve the problems, such as extra loss from auxiliary circuit, variable commutation duration, and delicate reliability etc., which exist in other ARCPIs.

辅助谐振换流逆变器拓扑结构中存在着诸如由辅助换流回路损耗引起的转换效率低、由负荷电流变化引起的变辅助换流周期和稳定性差等问题，为此提出了一种基于变压器辅助换流的新型ZVS-ZCS逆变器。

The device parameter as well as resonance frequency,mechanical quality factor and work band width were determined by the equiv- alent circuit input impedance admittance circle diagram .

分析压电式超声波换能器的等效电路，并由等效电路输入阻抗的导纳圆图确定了换能器的元器件参数以及谐振频率、机械品质因数和工作带宽等特征参量。

The operation condition of a series-resonant converter is equivalently analyzed under open-loop condition. OCC condition and selection basis of resonant parameter and switching frequency are determined. The relationships between LED number, transformer turns ratio and constant current error are also determined, which provide scientific basis for the selection of LED number and transformer turns ratio.

文中通过对串联谐振变换器开环工作状态的等效分析，确定开环恒流条件和谐振参数与开关频率的选择依据，以及LED数目、变压器变比与恒流误差之间的关系，为LED数目及变压器变比的优化选择奠定了理论基础。

Ignition pulses produced by the ignitor added to a boosted low frequency voltage produced by the circuit operating near its resonant frequency during start up of the lamp.

引燃器产生的引燃脉冲在灯起动的过程中加到在接近谐振频率工作的谐振电路所产生的经升压的低频电压。

This model builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator, and proves to be successful in predicting resonant modes, Hm ( m =1, 2, 3, 4), and in explaining the axially symmetric deviation of the levitated samples near the reflector and emitter.

该模型揭示了声悬浮性能和以声波长为参考的悬浮器几何参数之间的本征关系，成功地预测声场的谐振模式 Hm ( m =1， 2， 3， 4为模式数， Hm 为反射端-发射端谐振间距)，并解释了反射端和发射端附近的悬浮样品偏离对称轴的实验现象。

Such as: calibrating the laser system, calibrating the measurement region and focusing the CCD camera for the diffuser passage with complex shape, selecting the best incidence angle for the laser sheet,, setting the time parameter including the time between pulses and the time between records, designing the laser system, and selecting water fog with 1～5μm diameter as seedings for PIV measurement after comparing several particles. All of the work is useful to accumulate the PIV measurement experience in turbomachinery. 2. Experimental research of the unsteady flow in diffusers The instantaneous velocity fields within the vaneless and vaned diffuser were measured by using PIV technique.

本文在国内首次进行PIV测量系统对离心风机扩压器内部非定常流动的测量，为此，作者作了必要的实验前期工作：双谐振激光器工作特性的标定；针对扩压器复杂的流道形状，解决了片光源照射区域位置的标定和CCD相机的聚焦等问题；为复杂流道形状的扩压器内部流动的PIV测量选择了最佳片光源入射角度；选择了合适的PIV测量时间参数；为实现非定常内流的PIV测量设计了PIV系统的光路布置；根据非接触测量示踪粒子的选取原则，对几种示踪粒子进行了筛选，最终1～5μm的水雾粒子在本文实验条件下获得最佳效果。

This thesis describes the preparation of HTS rf SQUID, the design of the readout andthe innovation of our inductively coupled tank circuit. Using this tank circuit and ourreadout, we achieved the flux white noise of 15 〓/√Hz for an HTS YBCO rf SQUIDwith the loop size of 100×100 μ〓, and a field sensitivity of 24fT/√Hz by using a 1 inchwasher flux focusor.

文中描述了rfSQUID样品制备过程和我们所研制的rfSQUID读出电路的设计思想和实现方法，给出了我们所发明的电感耦合谐振回路的特性，对于内孔为100x100 μ〓的rf SQUID样品，用这种谐振回路和我们的读出电路，白噪声可测到15μ〓/√Hz左右，用1英寸的聚焦器可获得24fT／√Hz的磁场灵敏度。

Soft switching can improve the converters efficiency and reduce EMI. In comparison of some methods of approaching soft switching, this thesis presents a Diode Auxiliary Resonant Commutating Network which is composed by an auxiliary bridge and a resonant commutating inductor. This topology not only well realizes zero voltage switching, but also overcomes the parasitic oscillation in the secondary side Diodes. Simultaneously, this topology makes both the secondary side diodes and auxiliary diodes operate on the soft switching state too, which reduces more switching losses and provides requirement for the system to run stably under the condition of self-cooled.

软开关能够提高变换器的效率和降低EMI，通过比较目前多种实现软开关技术方案，本文研究了一种由辅助桥臂和谐振电感组成的二极管辅助谐振换流网络，不但很好地实现了ZVS，并且克服了副边二极管上寄生振荡；同时，该拓扑也使副边二极管和辅助二极管都工作于软开关状态，进一步降低了开关损耗，为系统能够在自冷的条件下稳定运行创造了条件。

With a "cat's eye" reflector as the reflecting mirror, the problems of laser adjustment and power stability can be solved.

将&猫眼&逆向器作为反射镜，组成&猫眼&谐振腔可提高激光谐振腔的稳定性。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。