机动再入飞行器主动段再入点约束闭路制导研究

基于机动再入飞行器再入制导段控制条件荷刻和难度大，必须为飞行器创造最佳的再入条件。本文对具有再入点约束的主支段闭路制导律进行了研究。根据飞行器椭圆弹道的性质、飞行器再入条件、球面几何和不动点原理给出了理想弹道的计算算法。为使飞行器能在主动段很快地进入到理想弹道上，系统采用了非线性的推力向量控制及预测制导方法。通过对新型号再入飞行器的制导系统的设计与仿真，表明该制导系统使飞行器全程飞行有很好的飞行性能。     

Arms control and disarmament in space: the rough road to Vienna 1984 : Part II

This article continues a detailed examination of the international legal and diplomatic questions relating to arms control and disarmament, focusing on space-based activities. These are importantly concerned with the development of anti-satellite (ASAT) systems and ballistic missile defence (BMD). This part of the article considers the US Presidential-Congressional dialogue - particularly the ASAT testing issue - and Presidential initiatives vis-à-vis the USSR. An epilogue to the original paper considers the diplomatic moves and policy shifts which contributed to the January 1985 US-Soviet meeting and the agreement to begin bilateral negotiations to consider space and nuclear arms.     

末端能量管理段迭代校正轨道算法研究

针对航天器进入末端能量管理段接口处时位置和航迹偏角存在大范围摄动的问题，提出一种使用迭代校正法的轨道快速生成算法。该算法可以根据航天器的具体初始状态，自动选择直接进场或者间接进场策略，快速生成可行的参考轨迹。首先通过跟踪轨迹地面投影实现侧向制导；根据末端能量管理段的起始点与终点的高度与速度约束生成参考动压-高度剖面，并跟踪此剖面实现纵向制导。然后采用迭代校正计算快速确定航向校准柱的位置与最终半径两个参数用以调整航程，保证航天器在末端的所有状态满足自动着陆段接口的边界约束。仿真结果校验了该算法可以根据航天器的具体状态快速生成符合约束条件的末端能量管理段飞行轨道，具有很好的鲁棒控制性能。     

论国际服务贸易的国家管制

国际服务贸易的国家管制基于维护国家主权的需要、市场失效的存在和服务贸易自由化的驱动等因素,其以形式多样的国内规制为主要管制方式、以市场准入作为服务业对外开放的管制要点、以保护性立法作为扶植国内服务业的重要手段.WTO框架下的<服务贸易总协定>作为最重要的国家管制国际服务贸易的国际协调规范,在尊重国家管制的自主权的前提下明确规定了国内规制的基本纪律.     

全面视角下“法律面前人人平等原则”的探讨

本文以全面视角审视了法律面前人人平等是什么，并就我们为什么需要法律面前人人平等原则，以及如何实现法律面前人人平等等问题进行了探讨。     

Optimal steering law of refractive sail

The interaction between electromagnetic waves and matter is the working principle of a photon-propelled spacecraft, which extracts momentum from the solar radiation to obtain a propulsive acceleration. An example is offered by solar sails, which use a thin membrane to reflect the impinging photons. The solar radiation momentum may actually be transferred to matter by means of various optical phenomena, such as absorption, emission, or refraction. This paper deals with the novel concept of a refractive sail, through which the Sun’s light is refracted by crossing a film made of polymeric micro-prisms. The main feature of a refractive sail is to give a large transverse component of thrust even when the sail nominal plane is orthogonal to the Sun-spacecraft line. Starting from the recent literature results, this paper proposes a semi-analytical thrust model that estimates the characteristics of the propulsive acceleration vector as a function of the sail attitude angles. Such a mathematical model is then used to analyze a simplified Earth-Mars and Earth-Venus interplanetary transfer within an optimal framework.     

Three-dimensional guidance law based on adaptive integral sliding mode control

For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engage-ment geometry is studied. Firstly, by introducing a finite time integral sliding mode manifold, a novel guidance law based on the integral sliding mode control is presented with the target acceler-ation as a known bounded external disturbance. Then, an improved adaptive guidance law based on the integral sliding mode control without the information of the upper bound on the target accel-eration is developed, where the upper bound of the target acceleration is estimated online by a designed adaptive law. The both presented guidance laws can make sure that the elevation angular rate of the line-of-sight and the azimuth angular rate of the line-of-sight converge to zero in finite time. In the end, the results of the guidance performance for the proposed guidance laws are pre-sented by numerical simulations. Although the designed guidance laws are developed for the con-stant speed missiles, the simulation results for the time-varying speed missiles are also shown to further confirm the designed guidance laws.     

自适应严格收敛非奇异终端滑模制导律

针对机动目标的末制导拦截问题，设计了一种带终端角度约束的有限时间收敛终端滑模制导律。首先，分析了现有非奇异终端滑模制导律存在的滑模面不能严格有限时间收敛的问题，进而构造了一种新型的非奇异终端滑模面。其次，设计了一种对目标机动上界的自适应估计，提出了一种自适应严格收敛非奇异终端滑模制导律的设计方法。最后，基于Lyapunov稳定性理论，证明了设计的制导律能够使得制导系统在有限时间内收敛到零，并且保证了滑模面在收敛过程中不存在非收敛因子，是严格有限时间收敛的。仿真实验验证了该制导律能够有效地拦截机动目标，同时和与现有的非奇异终端滑模制导律以及基于转换滑模面的非奇异制导律相比，拦截时间更短，终端攻击角度精度更高，导弹机动消耗的能量更少。     

基于双幂次趋近律的终端滑模舵机控制器设计

针对电动舵机系统的快响应鲁棒控制问题,提出了一种基于双幂次趋近律的全局非奇异终端滑模控制方法.首先,建立了舵机系统的数学模型,将气动干扰和摩擦建模为有界扰动;其次,根据系统模型构建非奇异终端滑模面,结合双幂次趋近律设计舵机控制器,从而保证滑模面的固定时间可达性,充分利用滑模控制方法的鲁棒性和不变性,并提高舵机系统的响应...     

19世纪末湖南维新思潮中近代民族国家观念的确立

19世纪末的湖南维新思潮,第一次较完整地确立了近代民族国家观念,而确立起近代民族国家观念的结果,就是在处理国际关系时,不再是盲目排外,而是以法理与理性来对抗外国的侵略,所以湖南维新派极力宣扬公法观念和主张文明排外的思想。不过,湖南维新思潮中的民族国家观念存在严重的局限性,即对帝国主义侵略性一面缺乏准确的认识。