用于大型固体推进剂火箭发动机的独特点火系统试验

本文介绍了用于大型固体推进剂火箭发动机的组合式无喷管、无壳体点火器方案的设计、分析及试验结果。该点火方案的主要优点是可以把60%左右的点火器消极重量变成药柱有效载荷。点火系统的主装药由点火器周围的发动机前段装药所构成。这段装药又是发动机推进剂药柱的一部分,设计成象一个小的低压无喷管火箭发动机,给主发动机推进剂段提供足够的压力和热流输出以实现发动机点火。前段推进剂的点火由一个比较小的径向排气的BKNO_3烟火剂药片点火器来实现。试验计划需验证三个方面的设计问题:     

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。     

A sulfur-based survival strategy for putative phototrophic life in the venusian atmosphere

Several observations indicate that the cloud deck of the venusian atmosphere may provide a plausible refuge for microbial life. Having originated in a hot proto-ocean or been brought in by meteorites from Earth (or Mars), early life on Venus could have adapted to a dry, acidic atmospheric niche as the warming planet lost its oceans. The greatest obstacle for the survival of any organism in this niche may be high doses of ultraviolet (UV) radiation. Here we make the argument that such an organism may utilize sulfur allotropes present in the venusian atmosphere, particularly S(8), as a UV sunscreen, as an energy-converting pigment, or as a means for converting UV light to lower frequencies that can be used for photosynthesis. Thus, life could exist today in the clouds of Venus.     

TDICCD相机像质综合评价研究

基于对影响航天相机成像质量诸多因素的综合考虑，文章试图从一个新的角度提出用MTF与SNR的乘积大于或等于9来综合评价航天相机成像性能的方法，为研制轻型航天相机提供参考。     

Production of neutrons from interactions of GCR-like particles

In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations.     

线性四元树表示图象的距离变换

二元数组表示的图象使用的距离概念运用于线性四元树表示。指出棋盘距离特别适合于线性四元树。定义线性四元树的棋盘距离变换为树中各个黑四分形中心到最近边界四分形黑一白边界的距离。这里提出的距离变换算法主要特点是(1)它是一种代数方法,(2)各个四分形只计算一次距离,和(3)距离信息非常快地传递到区域内部。该算法可以推广到线性八元树表示的三维客体。     

大电流输出DC-DC转换器瞬态响应的提高

涉及到64位微处理机使用的低压大电流输出DC—DC转换器，为了提高其动态响应而开发出同步并联倍流整流器。因此，在输出为1．3V／130A的原型机上以300A／μs的转换速率实现了50mV的输出电压偏差。     

星间红外探测与测量系统

文章主要介绍了具有凝视成像功能的红外探测系统的研究和设计。首先简要描述了红外测角系统的组成和工作原理；然后重点论述了红外探测系统的性能指标和光学设计；最后对红外探测系统设计研究作了总结和展望。     

再入制导和弹道跟踪误差分析

新一代可重复使用运载器对再入制导提出了更高地要求。目前的空间运输系统证明基于阻力加速度的制导方法是行之有效的。其基本概念是跟踪基准阻力加速度包线，在飞行过程中可根据需要更新这个包线。跟踪适当的阻力加速度包线保证了飞行器可以飞行准确的距离达到目标，同时满足弹道约束。在横向上，我们可采用类似于美国航天飞机的倾斜反转逻辑或航向角跟踪技术。本文推导出了基于反馈线性化的控制算法，并将其应用于可重复使用运载器纵向和横向的制导。最后，我们分析了阻力加速度跟踪的误差。     

微烟点火药剂GHN—1的性能

本文介绍了一种含硝胺的双基系微烟点火药剂的性能,其特点是能量高、燃速高、压力指数高(～0.9)和烟雾小,它可以应用于无烟固体火箭发动机。