谐振的

The aim of this research is to useDC link parallel resonance three---phase soft---switching techniqueto realize in inverter.

本研究课题的目标是三相软开关变频器DC直流环节的并联谐振，实现逆变桥上每个功率开关器件以零电压方式开通，达到软开关的目的。

But at low pressure, the continuum theory is no longer suitable and only the molecular dynamics method is passably valid. However, there have been yet a few studies on the squeeze film of micro-resonators in the free-molecule regime, and no 3D model of MD has been presented for SFD.

当气压很低时，气体连续介质模型不再适用，只能采用分子动力学方法但是，当前关于自由分子区域中的微谐振器件挤压膜阻尼的分子动力学研究非常少，为了避免计算量过大，还未有三维的挤压膜阻尼分子动力学模型。

In the design of the power supply, the main circuit topology frame uses half-bridge series resonant switching and parallel load connection, in which, an IGBT is adopted as the power switches, and features high operation frequency, high output power and fast response. In addition, the IGBT in the switch mode power supply has no hard turn-on or turn –off situation in transition, thus the disturbance to the power system is avoided.

相应的激光电源采用半桥软开关技术，串联谐振并联输出，IGBT 为主控制元件，实现了高频工作、高功率多路输出，响应快速；脉冲模式工作时避免了开关管的硬开关，减小了高次谐波对电网的干扰；无需镇流电阻也可实现气体稳定放电等特性。

In the design of the power supply, the main circuit topology frame uses full-bridge series resonant switching and parallel load connection, in which, four MOSFETs are adopted as the power switches, and by four pulses which UC3879 produces, high frequency operation and fast response are realized. In addition, the MOSFET in the switching power supply has no hard turn-on or turn-off situation in transition, thus the disturbance to the power system is avoided. Especially,by the use of high frequency transformer, PQ50/50, the switching power system can provide the steady discharge current without any amperite.

此开关电源采用全桥软开关技术、串联谐振并联输出，四个MOSFET管为主控制开关元件，通过脉冲产生电路UC3879产生的四路相关脉冲实现了高频交替开关，同时能快速响应输出的各种变化；避免了开关管的硬开关，提高了转换效率，另外通过采用高频变压器PQ50/50隔离了原副边，减小了高次谐波对电网干扰；无需镇流电阻也可实现气体稳定放电。

A novel zero-voltage and zero-current resonant pole soft-switching inverter was proposed to achieve zero- voltage and zero-current switching simultaneously when main power devices turn-on and turn-off. Therefore, turn-on capacitive losses could be reduced for devices which the intrinsic capacitor value cannot be neglected. Additionally losses caused by the tail current can also be reduced, when IGBTs are used as main switches.

提出一种新型的零电压零电流谐振极型软开关逆变器，可以在主功率器件开通和关断时，同时实现零电压和零电流，因此对于内部电容不能忽略的器件，可减小容性开通损耗，当绝缘栅双极型晶体管(insulated gate bipolar transistor，IGBT)作为主功率器件时，也可减小拖尾电流引起的损耗。

Driving the bimorph cantilever at one of its eigenfrequencies with an appropriate force feedback allows obtaining an effective Q-factor up to 103 in water from its original amount of ～ 40, that is, the sensitivity can be improved.

当双晶片在它的某一本征频率下被激励，通过调节一个适当的反馈力，它的机械谐振品质因数在水中可以从40增强到103，因此成像灵敏度获得显著改善。

The results show when the frequency ratio of the two-dimensional harmonic potential is a rational number, the quantum level density is discrete.

计算结果表明：当二维谐振子势的频率比值是有理数时，量子能级是分立的，能级密度中的每一条峰正好对应一个量子能级。

Plate and λ/2 plate were placed inside the Nd∶YVO4KTP green laser cavity with angle 90°between their fast axis.The composite plate composed of HWP,QWP and KTP has the function of QWP.The composite plate with Nd∶YVO4 can effectively suppress the coupling of polarized modes,and multi-longitudinal-mode lownoise green laser was obtained.Since the composite plate counteracted the phase shift induced by temperature sensitivity of quartz plate,the green laser operated with lownoise reliability in different output power and different operation temperature.The threelongitudinalmode, the noise of less than 0.5% and output power stability of less then 1% for 12 hour are obtained in the green laser.

介绍了一种LD泵浦腔内倍频全固体Nd∶YVO4KTP多纵模、低噪音、高功率稳定绿激光器在Nd∶YVO4KTP绿激光器组成的谐振腔内放置厚度约相等的石英晶体λ2波片和λ4波片，使两波片快轴夹角互呈90°，HWP、QWP与KTP构成复合波片，其作用相当于QWP，此复合波法与各相异性Nd∶YVO4共同作用有效抑制了腔内偏振模耦合，获得多纵模低噪音绿光输出此复合波片相互作用由于抵消了石英晶体波片温度敏感引起的相位延迟量漂移，所以此激光器在不同功率、不同工作温度下，均能稳定可靠地运转于低噪音状态实验结果为，绿光输出纵模数为3个，噪音小于0.5%，12 h功率稳定性优小于1

High-frequency continuous modulation on the high-power semiconductor laser is required in our ladar system. The theory and driving methods of the semiconductor laser is summarized in this article. Two kinds of driving circuit including linear power amplifier and resonance power amplifier are designed for continuous and quasi continuous modulated laser.

针对研制的无扫描激光雷达系统，需要对大功率半导体激光器进行高频连续调制，本文总结了半导体激光器的原理和驱动方法，并针对连续和准连续调制大功率激光器的特点分别设计了两套驱动电路，包括线性功率放大驱动电路和谐振功率放大驱动电路。

An important advantage of this system is that boththe energy level splitting and the decay rate of the DQD can be well tuned by varyingthe gate voltage.

利用双量子点冷却谐振子的优点在于，双量子点之间的能级差以及它的耗散速率都可以通过门电压来调节。

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％。