面对接近式威胁的在轨飞行器安全性分析方法

提出了一种针对非合作接近威胁飞行器的安全性分析方法,具备对多脉冲接近的威胁飞行器进行安全性分析的能力,所得结果可对自主规避决策提供支撑。文中给出了安全性分析流程,从能量约束等角度出发,选取脉冲冲量、交会时间以及最小相对距离三种参数作为安全性分析指标;随后对指标标准化,建立了多指标加权综合评价与决策模型。仿真结果表明,在本文模型下,非合作主动接近飞行器施加多脉冲机动变轨对目标器进行接近,其每次脉冲均会在安全性评价值中得到体现,算法可对脉冲真实意图进行准确判断。本文提出的安全性分析方法可推动空间复杂环境下卫星面对各种主动威胁时的安全性分析研究,对未来卫星防护体系及相关技术的研究具有一定参考意义。     

自适应变结构控制的切换函数研究

根据自适应变结构控制的基本思想 ,推导了滑模到达条件 ,并提出了切换线斜率的三种变化规律 :线性规律、幂次规律和指数规律 ,设计了相应形式的切换函数。最后 ,通过仿真实例对各种切换函数进行研究 ,仿真结果说明 :采用二次幂规律控制效果最佳。     

调频调相应答机距离零值测量新方法

叙述了分频调制度变换器的工作原理和时延测量。提出了根据测量FM信号源大频偏调制与小频偏调制的时延差来挑选出恒时延FM信号源,采用恒时延FM调制器构成FM—PM应答机（或FM—PM测距地面站）距离零值测量方法和设备,这是FM—PM体制侧音测距系统的一种距离零值测量新方法;提出了采用分频调制度变换器和非恒时延FM信号源构成FM—PM应答机（或FM-PM测距地面站）距离零值测量方法及设备。     

A study of L band scintillations during the initial phase of rising solar activity at an Indian low latitude station

The ionospheric scintillation and TEC (Total Electron Content) variations are studied using GPS (Global Positioning System) measurements at an Indian low latitude station Surat (21.16°N, 72.78°E; Geomagnetic: 12.90°N, 147.35°E), situated near the northern crest of the equatorial anomaly region. The results are presented for data collected during the initial phase of current rising solar activity (low to moderate solar activity) period between January 2009 and December 2011. The results show that within a total number of 656 night-time scintillation events, 340 events are observed with TEC depletions, Rate of change of TEC (ROT) fluctuations and enhancement of Rate of change of TEC Index (ROTI). A comparison of night-time scintillation events from the considered period reveal strong correlation amongst the duration of scintillation activity in S₄ index_, TEC depletion, ROT fluctuations and ROTI enhancement in the year 2011, followed by the year 2010 and least in 2009. The statistical analyses of scintillation activity with enhancement of ROTI also show that about 70–96% scintillation activity took place in equinox and winter months. Moreover, from a nocturnal variation in occurrence of scintillation with (S₄ ? 0.2) and enhancement of ROTI with (ROTI ? 0.5), a general trend of higher occurrence in pre-midnight hours of equinox and winter seasons is observed in both indices during the year 2011 and 2010, while no significant trend is observed in the year 2009. The results suggest the presence of F-region ionospheric irregularities with scale sizes of few kilometers and few hundred meters over Surat and are found to be influenced by solar and magnetic activity.     

测控应答机下行调制度问题的技术分析

针对应答机采用不同的接收信号功率控制方式，对下行测距调制度、残留遥控调制度以及转发噪声调制度的情况进行了理论分析，得到了各种情况下的调制度数学模型，可供读者在航天工程的测控链路设计及应答机设计时参考。     

城市吸引外资的业绩与潜力分析--以西部具有一级竞争力的五城市为实证研究

目的 通过对西部五城市吸引外资的业绩和潜力分析，有助于各城市正确定位，以便其今后更好地发展。方法 用业绩与潜力指数的方法，就西部五个城市吸引外资的业绩与潜力进行定量分析。结果 比较1999年与2003年西部五城市利用外资业绩指数可见，西安、成都、昆明三城市有所上升；重庆呈下降趋势。比较2003年五城市吸引外资潜力指数，排名为：成都、西安、兰州、重庆、昆明。结论 西部城市应从发挥资源优势、利用国家优惠政策、利用成本优势和加强基础设施建设四方面来吸引外资。     

单圈分子图的第一广义Zagreb指标的极值

第一广义Zagreb指标定义为0Rα（G）=∑i∈V（G）d（i）α,其中d（i）为i顶点的度,α为除0和1之外的所有实数。单圈分子图是指最大度不超过4且边数等于顶点数的简单连通图。本文通过一个引理,给出了单圈分子图的第一广义Zagreb指标达到极值的必要条件。     

航天器材料应用验证特点及其指标体系设计与优化

“材料应用验证”是为适应复杂工程研制任务而建立的一种材料多参数指标在特定服役需求下应用适用度评估的综合评价方法，也是通过一系列的试验、测试与表征手段获得材料各项性能数据、曲线、图谱，并通过综合分析确定材料应用可行性的分析方法。文章从航天器发展对高性能、多样化材料快速应用转化需求出发，阐释材料应用验证任务具有指标体系的综合性、通用性、短周期、低成本以及闭环式验证特点，进而提出了覆盖性、关重性、精准性、独立性、经济性的指标体系设计原则，以及材料应用验证的三层级五要素即材料批次稳定性、工艺适用性、环境适应性、服役安全性及组件健壮性指标体系设计及优化方法。     

直升机梯次使用控制及评价指标分析

直升机梯次使用控制是航空装备保障的一项重要工作，通过合理安排直升机的梯次使用，可以最大限度地发挥直升机的整体使用效能。针对直升机梯次使用控制中的难点及缺乏评价指标的问题，介绍梯次使用控制的两种方法，重点阐述梯次使用优化控制技术方法；推导分析不同参数对梯次使用控制的影响，提出衡量梯次使用控制效果的三个评价指标，并利用梯次使用优化控制技术方法进行算例分析。结果表明：单机年度任务最短时间与最长时间之和为常数，本文推导出的参数选择方法正确，提出的评价指标合理可行，可为下一步研究提供参考。     

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.