寄生振荡

The formation mechanism of the absolute instability and gyrotron backward wave oscillations is analyzed, and the methods to suppress the parasitical modes are discussed.The nonlinear theory model of gyro-TWT is consummated by considering the influence of tapered magnetic field and waveguide radius, electron velocity spread, and waveguide loss on electron beam-wave interaction. The large-signal characteristic of gyro-TWT, such as launching loss and absolute instability, are also analyzed in detail. This work establishes the foundation for the development of a gyro-TWT amplifier.

重点研究了两段损耗波导结构和损耗陶瓷结构回旋行波管中的电子注-波互作用，分析了绝对不稳定性和回旋返波振荡的形成机制和抑制寄生模式的方法；完善了回旋行波管的非线性理论模型，并考虑了磁场和波导半径渐变、速度零散、波导损耗等因素对注-波互作用的影响；详细分析了发射损耗、相位稳定性等回旋行波管的大信号特征，为回旋行波管放大器的研制奠定了基础。

The gain coefficient has been raised by the improvement of pump lamps form and energy feed system, the design of Nd:glass, the suppression of the parasitic oscillation, the use of corner reflector, protective glass with sol-gel anti reflection film and high efficiency xenon lamps.

在放大器的研制过程中应用了多种技术措施以提高放大增益，包括光泵形式的比较和选择，钕玻璃的种类，浓度，尺寸的选择，寄生振荡的抑制和包边玻璃的设计，。

And the leakage inductance of the transformer.

电容和变压器漏感引起的寄生振荡产生的。

But internal reflections an the boundaries of active medium can drastically enhance the onset of ASE, particularly if these reflections lead to a close path, i.e., a ray that is reflected upon itself. In the case, we have a strong feedback mechanism and as soon as the gain in the laser medium exceeds the reflection losses parasitic oscillations will set in.

但自发辐射的存在使得放大器工作介质会在信号光到达前开始发射激光，并且工作介质边缘的内反射能显著增大ASE的发射，尤其当这些反射能导致产生封闭路径时更是这样，当激光介质内的增益超过损耗时，就建立起寄生振荡。

The L band 500W SSPA module which has reached national level is the first sample of the Southwest China Research Institute of Electronic Equipment in this aspect;2. The method which to obtain fast rising time for narrow pulse width is got;3. The method of eliminating autoecious surge with pulse power amplifier is presented;The cause of pulse shape aberration is analysed.

二、工作的创新之处(1)L波段500W固态功放组件达到国内先进水平，是29所研制的第一台固态雷达功放组件；(2)得到了如何在窄脉宽情况下获得快速上升沿的方法；(3)提出了针对脉冲功率放大器的消除寄生振荡的方法；(4)对脉冲波形变差进行了分析。

The resonant phenomenon of Bridgeless Boost PFC with split inductor s is analyzed using experiments, simulation and equivalent circuit methods.

通过实验、仿真和等效电路模型分析方法对分立电感无桥Boost PFC电路电感电流上叠加有高频谐振电流的现象做出了详细的分析和研究，指出高频谐振是PFC分立电感与电路的寄生电容组成LC振荡回路所引起的，确定了谐振电流的路径和谐振频率的大小。

In this paper, thermal edffect in slab laser and parasitic oscillation in amplifier are analysized.Using the same method, we also calculate thermal effect in photonic crystal fibers with hollow claddings.

本文针对板条激光介质的特点，重点研究了板条激光器的热效应以及板条放大器的寄生振荡现象，并将热效应的计算方法推广到光子晶体光纤中。

Because parasitic parameters of the pulse transformer can not be eliminated,complicated oscillation should occur in the circuit.

由于脉冲变压器的寄生参量无法消除，会在电路中产生复杂的振荡过程。

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。

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。