反推力装置实现空中飞机减速及地面倒车滑行的应用

涡扇运输机利用反推力装置实现空中减速功能和地面倒车滑行功能,可提高军用飞机安全性、自主保障型性和机场适用能力。国外只有少数飞机具有该2项功能,对其设计需求、使用特点、系统设计和安全措施进行了分析,总结了为实现该2项功能在飞机气动和机翼、飞行控制、发动机进气、舱压控制等设计方面需注意的问题。最后给出设计和使用这项功能的建议。     

分层次教学在电工实训中的应用探索

分析在电工实训中采用分层教学的必要性,从教学对象、实训目标、实训内容、实训评价考核四个方面介绍分层教学在电工实训的实施情况,总结分层次教学的效果,提出分层次教学中应注意的问题。     

基于Rb-Xe体系核磁共振陀螺仪的Xe极化场测量方法

核磁共振陀螺仪具有小体积、高精度、低功耗等优点,是未来高精度微小型陀螺的主要发展方向之一。原子气室内 Xe 核自旋的极化是衡量原子气室性能的一个重要参数,直接影响陀螺的角随机游走, 因此准确快速地测量极化场有利于研制性能更优的原子气室。为了实现Rb-Xe体系的核磁共振陀螺仪快速、原位测量Xe的极化场,提出了利用Rb电子顺磁共振频移测量Xe极化场的方法。通过激励磁场翻转Xe极化场,推导了估算Xe极化场的简单公式。实验测量了在典型核磁共振陀螺仪装置中,10nT 量级的Xe极化场,结果与理论计算相符。表明这种方法能够快速有效的在核磁共振陀螺仪原位测量Xe的极化场。     

抗辐照通用扩展SiP芯片设计

研究微小卫星综合电子系统的SiP技术实现方法.首先介绍微小卫星综合电子系统结构的组成和采用SiP技术的必要性,然后对综合电子系统进行功能模块划分,并对其通用扩展模块进行详细的SiP设计,包括抗辐照器件选型、原型验证、SiP原理图、基板管壳一体化设计、建模仿真、制造加工、实装测试验证等,通过SiP技术实现了一种星载综合电...     

Derivation and validation of a similarity law for free-flight wind tunnel tests of parallel stage separation

Aiming at the safety problem of the stage separation of parallel reusable high-speed air vehicles, this paper studies the unsteady test method and focuses on deriving a similarity law of parallel stage separation free-flight wind tunnel tests. The new similarity law considers the influences of aerodynamic force and gravity on the motions of the two stages, as well as the influence of aerodynamic interference between the two stages on each other’s motion. From the perspective of multi-angle physical equations, the conditions to ensure that the two-stage separation trajectory of a wind tunnel test is similar to that of a real air vehicle are derived innovatively, so as to ensure the authenticity and credibility of wind tunnel test results. The similarity law is verified by an HIFiRE-5 air vehicle, and the separation trajectories of wind tunnel tests and the real air vehicle are obtained by numerical simulation. The research shows that the similarity law derived in this paper can ensure that wind tunnel free-flight tests have the ability to predict the two-stage separation characteristics of real parallel vehicles. By analyzing the separation trajectory curve of the typical state, it is found that the new method can ensure that the trajectory error of a wind tunnel test does not exceed 1%, which indicates that this method is credible. The establishment of the new method lays the foundation for subsequent wind tunnel tests and provides support for research on the safety of the stage separation of parallel reusable air vehicles.     

民用航空器座舱高低温环境下适航符合性研究

对民用航空器座舱高低温环境适航符合性开展分析.首先对座舱高低温环境适用的适航条款FAR/CCAR 25.831(g)和FAR/CCAR 25.1309(a)(b)(d)进行解读和分析;进一步得出基于人体核心温度的舱内可接受的高低温环境标准;随后,提出针对座舱高低温环境的适航符合性思路,包括:开展失效状态下座舱高低温环境...     

X射线脉冲星计时导航应用模式与空间试验进展

结合国家导航体系发展与工程应用迫切需求，主要讨论了X射线脉冲星计时导航的应用模式，并介绍了国内外空间试验进展。总结了脉冲星计时地基射电与空间X射线观测的特点和发展现状，阐释了脉冲星时研究与发展的重要意义；总结并归纳了X射线脉冲星导航的应用特点和现有水平，讨论了X射线脉冲星导航的技术优势和典型应用场景；总结了国内外X射线脉冲星计时导航的空间试验进展。根据国内外的空间试验结果，脉冲星时稳定度可达10-14量级，脉冲星导航精度可达到km量级，初步具备在轨应用价值。因此，加快推进国内脉冲星计时导航技术的在轨演示验证与工程应用具有重要意义。     

黑火药在真空环境下点火性能试验研究

黑火药作为固体火箭发动机中常用的点火药，是决定其工作性能的关键因素。为了研究黑火药在真空环境下的点火性能，通过真空点火试验，测试了不同点火结构、不同黑火药质量下的点火压力曲线和羽流现象，并与常压点火试验结果对比，分析了不同工况下黑火药点火性能的优劣。结果表明：真空环境下增加黑火药质量可以提高点火压强峰值，与常压条件相比提升幅度较小；与常压试验对比，真空下前端点火和尾部点火产生的压强峰值都会下降2MPa左右；不同黑火药质量的常压或真空点火试验中，前端点火试验样机到达压强峰值的时间都近似为5ms，而尾部点火试验样机到达峰值的时间不同；在真空点火试验中，羽流扩张角会在一段时间内变大或变小，即出现明显的黑火药不稳定燃烧现象，试验结束后有较多未燃烧完全的黑火药残留在发动机周围，而在常压点火试验中，这些未燃烧完全的黑火药颗粒会在空气中二次燃烧，黑火药残留较少。     

Space law education in China: Status quo,shortcomings and possible ways out

Space law education has an essential role in the space capacity building of a country because of its importance for human resources development in space law. Comparisons between Canada and China, the European Union and China and the United States of America (USA) and China in space law degree education, course, teaching methodology, institute and practice and communication platform are provided in an attempt to review some issues which exist within the Chinese space law educational system and to seek a better choice for China’s space law education reform. Chinese space law education has achieved noticeable progress over the past two decades. However, it is still limited in comparison to its counterparts in Europe and Northern America. The range of the space law degree education programmes and space-law-related courses is comparatively limited. A gap remains between space law education and practice in China. Chinese space law classes are still dominated by the teacher-centred teaching methodology, although several universities have some new teaching practices. The establishment of seven space law-related research institutes plays an increasingly important role in Chinese space law education, space law and policy research and legal advisory services for the Chinese government and non-governmental sectors. However, these institutes still have a long way to go in comparison with their counterparts in Europe and Northern America. While China has established domestic research platforms for space law communication through international cooperation, it does not provide space law practice platforms for space law education. While international space law does not provide a direct legal foundation for space law education in China, Chinese educational laws can lay a profound legal foundation for Chinese space law education. To promote its national expertise and capacity in space law, based on the three-pillar model and the experiences of its counterparts in North America and Europe, China should adopt a systematic and sustainable regime for its space law education.     

基于双四杆机构的可重复自动锁紧解锁装置

针对梦天实验舱对接、转位等工况，对日定向转动关节在轨多次锁紧解锁的需求，采用双四杆机构、自适应末端效应器等，设计一款可重复自动锁紧解锁装置。为了验证该锁紧解锁装置，利用研制产品，展开真空高温、真空低温、大气环境等多种状态下的锁紧解锁试验。结果表明:该机构可实现多种状态下的可重复自动锁紧解锁功能;在28 V直流工作电压下，锁紧动作执行时间为17.09~17.15 s，解锁动作执行时间为16.51~16.89 s。该机构具有高可靠、全角度、在轨可重复锁紧解锁等优点，在航天器锁紧解锁方面具有较大的工程应用潜力。