Capacity building in regional space cooperation: Asia-pacific space cooperation organization

The increasing gap in the space capabilities of different countries has led to the need for capacity building in modern times. Space capacity building of countries without or with limited space capacity via international cooperation with advanced spacefaring nations is a good practice towards intragenerational equity among all spacefaring countries, and between spacefaring and non-spacefaring countries at the same period of time. A case study is used here to show the current situation of the Asia-Pacific Space Cooperation Organization (APSCO) and its member states that are associated with their space capacity building. The study finds that neither the satellite technology development model developed by Wood and Weigel (2011) nor the model developed by Ercan and Kale (2017) is a good fit for the development of space capability in all of the developing countries. Therefore, using the APSCO member states as a case study may offer guidelines towards the space capacity building of other developing countries. Moreover, an in-depth analysis of the merits and flaws of APSCO’s capacity building programs through comparing them with similar projects carried out by the European Space Agency (ESA), the Asia-Pacific Regional Space Agency Forum (APRSAF) and some other countries is conducive to providing some references for regional cooperation in the field of space capacity building. While international space law and the APSCO Convention can provide the general principles for capacity building activities under the framework of APSCO, they are only relevant to the development of scientific and technological capacities for space and human resources rather than organizational development and legal frameworks. Some international soft laws can likewise provide guidance for the capacity building activities of APSCO and its member states in the areas of international direct television broadcasting, remote sensing and cooperative way. To enhance its and its member states’ space capabilities, APSCO, in the context of space commercialization and maintaining the long-term sustainability of outer space activities (LTSOSA), should establish a comprehensive internal regime that addresses scientific and technological capacity building for space, human resources, organizational development and legal frameworks, a flexible regime for international cooperation with other developed spacefaring nations and international organizations with relevant technical capabilities and an internal research center for space law, and actively expand its membership by embracing other economically or technologically developed spacefaring nations in the Asia-Pacific region.     

浅谈新形势下高职院校团建工作的挑战

高校共青团组织作为党联系青年学生的桥梁和纽带,在引导青年学生树立共同理想、服务青年成长成才、全面提高其素质方面负有重要责任。在经济不断开放、不断发展,教育体制不断改革等新的形势下,高校团建工作的开展有了更为广阔的舞台,但同时也面临许多挑战。主要就新的形势下高等职业技术学院团建工作所面临的挑战及如何应对问题作一点浅显分析。     

Conceptual design,modeling and compliance characterization of a novel 2-DOF rotational pointing mechanism for fast steering mirror

In this paper, a novel 2-DOF rotational pointing mechanism (RPM) is designed inspired by the guidelines of the graphical approach. The mechanism integrates with a fast steering mirror (FSM) for compensating pointing errors of a laser beam. The design intends to achieve an angular travel of ±10 mrad and steers a 25 mm mirror aperture. A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism configuration. Compliant mechanism-based RPM ensures high precision and compactness. Compliance characteristics are established based on the stiffness matrix method for four different planar flexure layouts. One layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error, thus informing the design space. Rotational stiffness in both the in-plane rotational axes and stress is determined based on finite element analysis (FEA). The wire electrical discharge machining (EDM) is employed for developing the proof of concept for the RPM and is then assembled in FSM. Experiments are conducted to determine the rotational stiffness and angular travel about both in-plane rotational axes. Comparison among theoretical, numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel range. The maximum theoretical error is less than 5.5% compared with FEA while, the experimental error has a mean of 5% and 3% for both rotational axes thus satisfying the intended design requirement.     

军工电子产品外协技术状态控制研究

介绍了军工电子产品外协技术状态控制的现状,分析了控制难点,从控制源头、加强过程控制、供应商动态评价、建立与供方互利的关系四个方面提出了加强军工电子产品外协技术状态控制的思路和对策。     

通用航空产业发展途径探讨

通用航空由于应用范围广且对经济有较强的拉动作用,受到了各级政府部门的重视,国家的＂十二五＂规划已经将其列为国家的战略新兴产业。针对我国通用航空发展极度落后的现状,分析了制约通用航空产业发展的主要因素,包括空域管制、通用航空法律法规不健全、专业人才短缺以及航空保障设施落后等,探讨了通用航空产业的发展途径,提出了加强宣传、政府主导、专业人才培养等一些有价值的建议。     

Capturability of 3D RTPN guidance law against true-arbitrarily maneuvering target with maneuverability limitation

The capturability of the Three-Dimensional(3D) Realistic True Proportional Navigation(RTPN) guidance law is thoroughly analyzed. The true-arbitrarily maneuvering target is considered, which maneuvers along an arbitrary direction in 3D space with an arbitrary but upperbounded acceleration. The whole nonlinear relative kinematics between the interceptor and target is taken into account. First, the upper-bound of commanded acceleration of 3D RTPN is deduced,using a novel Lyapunov-like approach. Sec...     

无需变轨实现单航天器对星座中多卫星的近距离接近

针对日前广泛应用的相位同构星座，讨论了一种无需变轨实现单航天器与多颗卫星近距离接近的轨道设计方法。其设计思想是首先根据接近任意两颗卫星轨道的约束条件得到轨道簇，再利用搜索的方法从中找出能接近其他一颗或多颗卫星的轨道。研究表明，利用这种方法能设计得到至少接近三颗非共轨卫星的多条轨道。文中给出了一个算例，针对描述符为60：18／6／2的星座，得到了多条能接近3—5颗卫星的轨道。     

一种基于拟合目标函数随动系统的建模与仿真

随动系统主要用于跟踪空中飞行目标,目标的方位可以由水平方位角和高低角度确定,由于水平角和高低角随时间变化的函数往往很复杂,在求控制系统的稳态误差时,难以对目标输入函数进行拉普拉斯变换;采用一种用曲线来拟合逼近目标函数的方法,达到了很好的效果;进而根据系统精度要求可以确定控制系统的放大增益。通过对随动系统的控制和分析,建立控制系统的数学模型,得到随动系统跟随目标函数的响应曲线;随动系统要求有很好的稳定性和很高的精度,采用了一种滞后-引前的校正方法,用MATLAB仿真模拟,并进行时域和频域的综合分析,得到了理想的仿真结果。     

核心机驱动风扇级气动参数径向分布对变循环发动机性能的影响

为了考虑部件流动细节对发动机性能的影响,采用迭代耦合方法建立了变循环发动机(Variable cycle engine,VCE)多维仿真模型。在VCE多维仿真模型中,核心机驱动风扇级(Core driven fan stage,CDFS)三维仿真模型的结果以流量修正因子、压比修正因子和等熵效率修正因子的形式反馈给VCE零维仿真模型,对CDFS的特性图进行修正。在考虑CDFS气动参数径向分布的影响时,根据CDFS涵道比及三维仿真结果,计算CDFS内、外涵的流量、压比及等熵效率,同时在VCE零维仿真模型中以CDFS外涵特性图的辅助变量β值取代CDFS涵道比作为迭代变量。结果表明:在VIGV角度为15°时,外涵区域的压比低于内涵区域的压比;而在VIGV角度为40°时,叶尖区域的流动分离更为严重,导致转子进口的攻角增大,转子叶尖区域的负荷加重,外涵区域的压比高于内涵区域的压比;CDFS气动参数径向分布对VCE性能有较为明显的影响,CDFS较高的内涵压比及较低的外涵压比可使发动机核心流流量增大及总增压比升高,进而引起发动机推力的增大,推力最大变化为1.75%。