氩离子激光器输出光功率稳定度与光反馈应用

通过实验观测氩离子激光器工作电流与输出光功率及其稳定性之间的关系，采用光反馈解决了反馈工作点的设置和跟踪调解，使输出光功率稳定性得到明显提高。     

A compact shock-assisted free-piston driver for impulse facilities

A free-piston driver that employs entropy-raising shock processes with diaphragm rupture has been constructed, which promises significant theoretical advantages over isentropic compression. Results from a range of conditions with helium and argon driver gases are reported. Significant performance gains were achieved in some test cases. Heat losses are shown to have a strong effect on driver processes. Measurements compare well with predictions from a quasi-one-dimensional numerical code. Received 7 September 1996 / Accepted 5 October 1996     

一种铁氧体移相驱动器专用集成电路

介绍了ＳＡ０１８铁氧体移相驱动器专用集成电路的工作原理，电路设计和实验结果。该电路的内部电路设计有双路激励驱动器，放大器，积分器和双路高速比较器等功能单元。将铁氧体移相器的激励驱动器和相位控制器融于一体，大大减少了铁氧体移相器的外围设计。     

用DEA方法测算产出弹性

本文主要讨论并给出了把ＤＥＡ模型Ｃ２ＧＳ２用于测算产出的弧弹性的方法。     

Study on the possibilities of controlling the laser output beam properties by an intracavity deformable mirror

The possibilities of controlling the laser beam properties by a deformable mirror introduced into the laser optical cavity were studied theoretically and experimentally. The experiments were performed under conditions of an industrial high power transverse flow cw CO₂ laser operating with a stable resonator of a folded configuration. A deformable bimorph mirror of a surface profile controlled by the voltage applied to the mirror electrodes is implemented to the laser system as a back cavity mirror or as a one of the inner folding mirrors. The near-and far-field characteristics of the laser beam versus the resonator configuration controlled by the changes of the focal length of the deformable mirror are discussed in the paper. The analysis reveals that the resonator with an inner deformable mirror is much more sensitive to the mirror curvature variations than the resonator in which the deformable mirror is used as a back cavity mirror. The presented results show that dynamic and controllable changes in the resonator properties result in the controlled modification and optimisation of the laser output power and spatial parameters of the laser radiation.     

遥感器CCD驱动器热设计及其在摄像过程中的温度变化

CCD驱动器是航天成像遥感器摄像过程中的主要热源之一。防止CCD驱动器过热是保证其正常工作的重要方面。介绍了遥感器的工作模式和对CCD驱动器采取的热控制措施。通过热平衡试验,利用回归的方法,对CCD驱动器在摄像过程中的温度变化规律进行了分析,同时对热控制效果进行了评估。CCD驱动器工作时升温速率在0.85℃/min左右,整个摄像过程中最高温度约为26℃,所实施的热控制措施效果理想。     

新闻直播系统中字幕机备份及应急处理实例

简单介绍新闻直播系统中字幕机的接入方法、备份机制、数据共享以及应急处理方案。     

Runge–Kutta interpolants for high precision computations

Runge–Kutta (RK) pairs furnish approximations of the solution of an initial value problem at discrete points in the interval of integration. Many techniques for enriching these methods with continuous approximations have been proposed. Here we construct C ¹ continuous, eighth and ninth order interpolation methods for a recently appeared RK pair of orders 9(8). These interpolants share a very small leading truncation error making them suitable for use at quadruple precision, i.e. 32–33 decimal digits of accuracy. Extended numerical results justify our effort.     

Parallel feedforward class-AB control circuits for low-voltage bipolar rail-to-rail output stages of operational amplifiers

A new family of class-AB control circuits for bipolar rail-to-rail output stages of operational amplifiers is presented. Step by step, we report the development of five simple class-AB control circuits showing the advantages of using parallel feedforward. The circuits have been designed in such a way that temperature, supply voltage and process parameters have little influence. To test the output stages, one of them has been implemented in a very simple two-stage operational amplifier on a semi-custom chip. Measurements show a bandwidth of 2.5 MHz, a gain of 40 dB, a quiescent current of 23µA and a maximum output current of 250µA. Simulation results of three other simple operational amplifiers with the new class-AB control circuits are shown, which have a higher gain and maximum output current.     

基于优化探测窗口的光斑质心探测方法

哈特曼-夏克波前传感器进行波前探测时，用子孔径光斑强度的一阶矩来计算光斑质心位置，子孔径窗口作为探测窗口，但探测时子孔径窗口内噪声对一阶矩有很大的影响，会使质心探测精度产生很大的误差。因此在计算质心位置时探测窗口的选取对探测精度有重要影响，必须选取合适的探测窗口来提高光斑质心探测精度。为此，在传统算法的基础上提出优化探测窗口的方法来提高质心探测精度,仿真和实验结果表明新方法提高了质心探测的精度，未经处理的高噪声恢复波前的波前残差峰谷值是2.851 4λ，均方根值是0.606 3λ，优化探测窗口后波前残差的峰谷值是1.636 2 λ，均方根值是0.367 1 λ，重构误差减小了40％。证明了算法的可行性和稳定性。