第二代可重复使用运载器及其再入制导技术

可重复使用运载器是未来航天运输系统发展的主要方向,各大国正围绕其关键技术开展积极的研究。第2代可重复使用运载器对再入制导技术的自主性、安全性和可靠性提出了更高的要求。分析了各国可重复使用运载器的发展概况,给出了可重复使用运载器再入的特点。重点综述了针对第2代可重复使用运载器开发的各种新型再入制导方法,并讨论了有待深入研究的可重复使用运载器再入制导关键技术。     

我国重复使用运载器发展思路探讨

重复使用运载器是航天运输系统未来发展的主要方向,具有重要的军事和民用价值。一次性使用运载器技术日益成熟,世界航天大国都在积极开展重复使用运载器方案探索与关键技术研究。简要分析了世界开展重复使用运载器的研究状况,总结了重复使用运载器的发展趋势,并根据我国的技术现状与特点,提出了我国重复使用运载器“顶、背、跑”的渐进式发展思路。     

可重复使用运载火箭发展研究

可重复使用航天运载器是人类获得低成本、常态化进入空间能力的重要途径,20世纪80年代至今,世界各国对不同类型的可重复使用航天运载器及关键技术进行了大量研究。重点分析了可重复使用运载火箭的发展和技术特点,对可重复使用运载火箭的不同回收方式进行了对比分析,并对我国发展可重复使用运载火箭的途径提出了设想和建议。     

液氧甲烷重复使用运载器关键技术发展研究

基于液氧甲烷发动机的重复使用运载器在重复使用和使用维护方面具有优良的性能,成本更低。世界各国正在加速开展相关研究及工程研制,典型代表包括火神运载火箭、朱雀二号运载火箭等。对基于液氧甲烷发动机的重复使用运载器的技术特点、面临的技术挑战进行分析,并基于此提出后续重点研究内容,包括重复使用总体设计与评估技术、上升再入返回着陆一体化制导导航与控制技术、大尺寸轻质结构与制造技术、重复使用液氧甲烷发动机技术、健康管理预测与重复使用运行维护技术、重复使用热防护技术等,为后续开展液氧甲烷重复使用运载器工程研制奠定基础。     

重复使用运载器的近期发展

简要介绍了重复使用运载器的近期发展状况、包括美国的Ｘ－３３／ＲＬＶ技术计划,日本的重复使用运载器计划和欧空局的欧洲未来空间运输研究计划等,最后针对重复使用运载器的发展提出了一些看法和建议。     

美国重复使用运载器的发展历史、现状及启示

简要回顾了美国过去40多年来重复使用运载器及其支撑技术的发展历史，讨论了其中所取得的成就及存在的问题，总结了一些经验教训，为重复使用运载器的研究与发展提供借鉴。     

2017年国外航天运载器发展分析

2017年,全球航天发射活动稳步增长,商业航天公司发射次数大幅提高。各国积极发展下一代大中型运载火箭、快速响应小型运载火箭和载人深空探索的重型运载火箭,继续研究和验证火箭动力、吸气动力的可重复使用运载器,并对2017年度国外航天运载器进行了回顾和分析,最后对2018年国外运载器的发展进行了展望。     

美国重复使用运载器空气动力学研究现状

描述了美国重复使用运载器如航天飞机轨道器、X-33、X-34、X-38等在空气动力学研究方面的最新进展情况,总结了美国重复使用运载器空气动力学研究的新特点,对我国重复使用运载器空气动力学发展提出了个人建议.     

国外RLV研究对我国发展运载器的启迪

从航天运输系统发展的特点出发，论述了国外可重复使用运载器(RLV)的研究概况和发展目标，分析了航天运载器的发展趋势，并对我国RLV的发展思路和重点进行了探讨。     

航天运载器及低温贮箱的热防护系统

低温贮箱是航天运载器最大的结构部件,作为压力容器用来贮存液氢、液氧推进剂,也作为运载器的主承力结构,起着支撑热防护系统以及为其它系统仪器设备提供安装基础和空间的作用.随着航天运载技术的不断发展,低温贮箱热防护系统已经成为重复使用运载器的关键技术之一.介绍了一次性使用运载器热防护系统的发展历史,以及重复使用运载器低温贮箱热防护系统的最新进展.     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Design and Implementation of One Missile Visual Simulation System Based on OpenGL

The implementation of a missile＇s visual simulation system is explained that is developed with OpenGL（open graphic library） and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile＇s data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Dynamic Encryption Technology in Ad-hoc Networks

A new dynamic encryption application in ad-hoc networks is proposed. The advantages of this method are its being able to use the previous ciphertext as a seed of a new encryption process, rendering the encryption process effective in all communication process by continuous dynamic key generation together with synchronization, and its capability to cut back on system bandages to a greater extent, which is valuable for the ad-hoc circumstance. In addition, the rationality and effectiveness of this novel encryption method have been verified by the test results.