表面安装器件及表面安装技术

本文较详细地介绍了表面安装器件,概述了表面安装技术的特点及现状,提出了我国机载电子制造领域应用该技术的几点想法。表面安装技术SM叮(S也企沈MoUD山犯lb出一加拓留)是新兴的第四代电子组装技术.它是由器件、材料、工艺     

MX导弹喷管用先进材料评论

目前正在进行研制石墨材料,准备用于MX 第一级和第二级固体火箭喷管的入口部,喉部,后喉部,出口锥和可延伸出口锥。这些材料必须经受住新型洲际弹道导弹(ICBM)喷管系统的苛刻的结构、化学侵蚀,粒子冲刷和高温环境。该系统的燃烧室压力可达127公斤/厘米~2,火焰温度为3700°K 至3922°K。叙述了第一级和第二级全尺寸试验喷管的现状。还提出了在喷管设计、石墨材料研制以及预期性能改进方面进一步工作的方向。     

孙有彬逝去风景的记忆和忧思

天高云淡的漫射光线下，美丽的莲花湖呈现出丰富的色彩和细腻的影调。蔚蓝的湖水清波荡漾，浓密的森林郁郁苍苍，浅浅的湖滩上，油绿的草甸与映着天光的湖水颜色一起搅和，而就在如此祥和宁静的画卷中俯瞰草甸，景况丰伟的天地之间，几匹骏马和几个牧马人，却又为画卷平添了若干生动的气息。摄影家孙有彬先生告诉说，为了拍摄这幅图片，他曾在湖边荆棘遍布．怪石林立的山崖上艰难地攀爬了两个小时。     

Ground and on-orbit command and data handling architectures for the Active Rack Isolation System microgravity flight experiment

The Active Rack Isolation System [ARIS] International Space Station [ISS] Characterization Experiment, or ARIS-ICE for short, is a long duration microgravity characterization experiment aboard the ISS. The objective of the experiment is to fully characterize active microgravity performance of the first ARIS rack deployed on the ISS. Efficient ground and on-orbit command and data handling [C&DH] segments are the crux in achieving the challenging objectives of the mission. The objective of the paper is to provide an overview of the C&DH architectures developed for ARIS-ICE, with the view that these architectures may serve as a model for future ISS microgravity payloads. Both ground and on-orbit segments, and their interaction with corresponding ISS C&DH systems are presented. The heart of the on-orbit segment is the ARIS-ICE Payload On-orbit Processor, ARIS-ICE POP for short. The POP manages communication with the ISS C&DH system and other ISS subsystems and payloads, enables automation of test/data collection sequences, and provides a wide range of utilities such as efficient file downlinks/uplinks, data post-processing, data compression and data storage. The hardware and software architecture of the POP is presented and it is shown that the built-in functionality helps to dramatically streamline the efficiency of on-orbit operations. The ground segment has at its heart special ARIS-ICE Ground Support Equipment [GSE] software developed for the experiment. The software enables efficient command and file uplinks, and reconstruction and display of science telemetry packets. The GSE software architecture is discussed along with its interactions with ISS ground C&DH elements. A test sequence example is used to demonstrate the interplay between the ground and on-orbit segments.     

俄罗斯S-300P和S-300V地空导弹武器系统

俄罗斯的Ｓ—３００实际上包括两大系列地空导弹武器系统，即Ｓ一３００Ｐ和Ｓ—３００Ｖ。俄军方规定，凡是射程超过１５０公里、射高在２５到３０公里之间的地空导弹武器系统都包括在Ｓ－３００系统中。在俄罗斯的地空导弹武器中，属于Ｓ—３００系列的有Ｓ一３００Ｐ半机动与机动战略防空系统和Ｓ－３００Ｖ机动式战区防空系统。在研制初期，前者以拦截低空喷气式进攻性空袭兵器为主，后者主要拦截战术弹道导弹。但在目前，Ｓ－３００这两大系列地空导弹已发展成为反巡航导弹、反战术弹道导弹、反飞机并举的多用途防空与反导系统。Ｓ—３…     

MX导弹喷管用先进材料评论 Ⅱ 第一级喷管的先进材料

本文是评论MX导弹喷管先进材料的三篇文章中的第二篇。第一篇文章于1977年4月在SAMPE季刊中发表(译文见“固体火箭技术”1978年第二期第99—105页),综述了MX导弹喷管对材料的要求,叙述了石墨材料的结构、性质和性能之间的关系。本文继续对MX的第一级和第二级发动机喷管所用先进材料进一步进行评价。     

中国海洋一号卫星遥感图像GPS地理定位算法研究与实现

介绍了GPS数据在中国海洋一号卫星遥感图像地理定位中的应用,即利用中国海洋一号卫星下行数据中的GPS数据和轨道拟合技术,得到卫星轨道参数,从而对中国海洋一号卫星十波段水色扫描仪获取的遥感图像进行地理定位。该技术突破了遥感图像地理定位必须利用卫星轨道报的传统手段,为配备有GPS的新一代遥感卫星的用户提供一种简便有效、定位精度高的地理定位方法。该方法定位精度优于利用轨道报进行地理定位得到的结果。     

Effect of weightlessness on posture and movement control during a whole body reaching task

Here are reported preliminary results of the “Synergy” experiment performed aboard the Russian orbital station “MIR” in July 1993 (Altaïr Mission). The experiment was carried out before, during, and after the space flight of two astronauts (S1 and S2). The duration of the flight was 21 days for S1 and 6 month for S2. The subjects were tested during preflight, inflight and postflight. The astronaut subjects were fixed on the ground by the feet. They were asked to pick up a box in front of them on the ground. Two velocities of movement and two distances of the target to be reached were tested. The movement of several small markers placed on the body was recorded on video tape.

Results show that the shape of head and hand trajectories in the sagittal plane remains roughly the same during the flight in spite of the modification of mechanical constraints. Trajectory invariance does not result in joint angular displacement invariance. These data indicate that the planning of the movement takes place in terms of head and hand trajectories rather than joint rotations as it was previously suggested for simple arm reaching movement.     

Goals and preparation method for ground operations for the manned space flight Altair

The mission's success fully depends on the Payload Operations conducted during the space flight. The Ground Team has to be trained to assist the Space Crew, to replan the cosmonaut's activities when contingengies occurr onboard and to change or cancel Payload activities when required. In order to act efficiently during the mission, the Ground Team must be prepared in advance of the flight and able to operate special tools for tracking the mission's progress, anticipating problems and taking decisions in realtime.

This document sets out the approach for conducting such a preparation for Ground Operation. It will be focused on the Altaïr mission performed in July 1993 onboard the Russian Mir space station.     

Remote assistance experiment during the manned space flight Altair

This remote assistance trial, performed within the framework of the manned space flight Altaïr, was carried out by CADMOS (CNES), with the cooperation of the Sub-directorate of CNES Operational Systems, Medes, LBM of Tours and Christol Consultants. It consisted of supplying the cosmonaut performing the Orthostatism experiment (echograph acquisition) on board the Mir station with realtime assistance by an expert (LBM of Tours) working from the ground on the CADMOS premises. The various steps of the approach followed during the preparation phase are described, as well as the technical means of communication used between the Mir station and CADMOS.