该文提出了一种可用于压电陶瓷驱动电路的低纹波、高稳定性的直流线性稳压电源的设计方案, 分析了其工作原理并测量了其电学特性。采用可调三端稳压器为核心器件, 利用低温漂电压基准源提高了稳压器的反馈电压, 采用瞬态抑制二极管抑制了上电瞬间的冲击浪涌, 有效地抑制了输出纹波, 提高了电源的电磁兼容性和可靠性。实验结果表明, 该电源可输出10~200 V的正负双极性电压, 负载调整率小于0.5%, 纹波小于10 mV, 现已成功应用于以PA85功率放大器为核心器件的压电陶瓷驱动电路中。

No-reference quality assessment aims at designing objective assessment criteria consistent to subjective perceived quality without any knowledge about reference image. This paper proposes a no-reference quality assessment algorithm specific to JPEG images. Blocking artifact in JPEG images is caused by the block based quantization of frequency coefficients, which is equivalent to applying low pass filtering in each block. In view of this idea, the algorithm in this paper was used to realize the quality assessment of JPEG images by quantizing the difference of power spectrum distribution between inner-block and inter-block. The assessment method proposed in this paper owns low algorithm complexity, clear physical meanings, free from learning and training and other advantages. Compared with most presented algorithms, the assessment results of proposed algorithm demonstrate a higher correlation to the subjective perceived quality.

以MEMS微变形镜驱动方式的选取为出发点, 从光学特性和力学特性两方面对MEMS微变形镜进行分析, 从中得出相关结构参数对微变形镜性能的影响关系, 并在此基础上结合补偿激光二极管抽运固体激光器(DPL)热畸变的使用要求设计了一种新型MEMS连续面型微变形镜, 并采用设计的MEMS变形镜搭建了一个闭环自适应光学实验系统, 补偿了激光光束的热畸变。实验结果显示该MEMS连续面型微变形镜可对腔内畸变进行有效补偿, 同时提高了激光器的输出功率及光束质量。

A novel hybrid surface micromachined segmented mirror array is described. This device is capable of scaling to large apertures for correcting time-varying aberrations in laser applications. Each mirror is composed of bottom electrode, support part, and mirror plate, in which a T-shaped beam structure is used to support the mirror plate. It can provide mirror with vertical movement and rotation around two horizontal axes. The test results show that the maximum deflection along the vertical direction of the mirror plate is 2 microns, while the rotation angles around x and y axes are +-2.3 deg. and +-1.45 deg., respectively.