The influence of dose, dose-rate and particle fragmentation on cataract induction by energetic iron ions.

Because activities in space necessarily involve chronic exposure to a heterogeneous charged particle radiation field it is important to assess the influence of dose-rate and the possible modulating role of heavy particle fragmentation on biological systems. Using the well-studied cataract model, mice were exposed to plateau 600 MeV/amu 56Fe ions either as acute or fractionated exposures at total doses of 5 - 504 cGy. Additional groups of mice received 20, 360 and 504 cGy behind 50 mm of polyethylene, which simulates body shielding. The reference radiation consisted of 60Co gamma radiation. The animals were examined by slit lamp biomicroscopy over their three year life spans. In accordance with our previous observations with heavy particles, the cataractogenic potential of the 600 MeV/amu 56Fe ions was greater than for low-LET radiation and increased with decreasing dose relative to gamma-rays. Fractionation of a given dose of 56Fe ions did not reduce the cataractogenicity of the radiation compared to the acute regimen. Fragmentation of the beam in the polyethylene did not alter the cataractotoxicity of the ions, either when administered singly or in fractions.     

High speed driving of a gain-switched laser diode with anexponential transmission line

With the increase of information capacity of an airborne system, high speed driving of laser diodes have been of interest. In order to match the low resistive LD, proposed in this paper is an exponential transmission line, which is used as preshaping to compensate the pattern effect in gain switching of laser diodes. It also will be used to overcome the effect of parasitic elements in high speed driving to improve the rise and trail edges of the output waveform. An accurate circuit model of the exponential line for the PSPICE program has been developed and simulations are conveniently carried out by employing PSPICE     

电泵起停控制与电机多功能保护电路

某些场合，电泵要在特殊的环境和条件下长期连续的工作，因此配置特殊的起停控制电路和保护电路是完全必要的，所以设计了本文介绍的电泵起停控制与多功能保护电路。电路主要由集成件构成。文中扼要介绍的是电泵欠载延时断电保护，过载分级延时断电保护电路，以及欠载停机后延时自动再起动电路。     

星载遥感器在模拟空间环境中辐射定标设备研制

文章简述了星载遥感器辐射定标设备的研制过程及其在模拟空间环境中的调试过程,试验证明了该设备设计的合理性。     

热惯性对热冲击半无限体热应力影响非傅立叶效应研究

考虑超快速加热引起传热过程的非傅立叶效应,基于线性热弹性理论和表面热惯性特性,建立了带惯性第一类边界条件的半无限体的动态温度场、热应力场方程组。用拉普拉斯变换法对方程组进行求解。结果表明,快速加热在半无限体内产生温度场和应力场,且热和应力呈波动输运机制。讨论了温升率或热惯性对半空间温度场和应力场的影响,比较弹性波波速与热波波速之比动态热应力的影响。     

疲劳裂纹扩展速率试验数据的可靠性分析模型

以指定ΔＫ下的ｄａ／ｄＮ服从对数正态分布为基础，提出３种ｄａ／ｄＮ试验数据统计处理方法；依据一组４０ＣｒＮｉＭｏ材料的ＣＴ试样的试验数据处理结果，对３方法进行了分析对比。     

低轨卫星面阵凝视成像技术研究

文章介绍了面阵凝视成像的工作原理及特点，阐述了低轨卫星对地观测凝视成像面临的像移问题及其解决措施，对像移补偿装置与二维指向机构的结合做了初步探讨。     

遥感卫星CCD相机光学系统的热补偿设计

文章对遥感卫星CCD相机光学系统的热补偿设计进行了论述。     

控制增稳系统参数对飞机纵向飞行品质的影响

本文以纵向控制增稳系统为例,通过计算分析控制增稳系统的几个主要参数对飞机飞行品质的影响与作用,进一步讨论控制增稳系统的参数选择问题。     

Investigation of corona initiation voltage at reduced pressures

The results of an experimental study of the 60 Hz ac corona inception voltage at reduced pressures for a cylindrical conductor and a parallel ground plane are presented. Several spacings and bare and insulated conductors of several diameters are considered. Empirical expressions from which a reasonably accurate prediction of the corona inception voltage (CIV) may be made have been inferred from experimental data