Design of tracking mount and controller for mobile satellite laser ranging system

In this study, we have proposed and implemented a design for the tracking mount and controller of the ARGO-M (Accurate Ranging system for Geodetic Observation - Mobile) which is a mobile satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute (KASI) and Korea Institute of Machinery and Materials (KIMM). The tracking mount comprises a few core components such as bearings, driving motors and encoders. These components were selected as per the technical specifications for the tracking mount of the ARGO-M. A three-dimensional model of the tracking mount was designed. The frequency analysis of the model predicted that the first natural frequency of the designed tracking mount was high enough. The tracking controller is simulated using MATLAB/xPC Target to achieve the required pointing and tracking accuracy. In order to evaluate the system repeatability and tracking accuracy of the tracking mount, a prototype of the ARGO-M was fabricated, and repeatability tests were carried out using a laser interferometer. Tracking tests were conducted using the trajectories of low earth orbit (LEO) and high earth orbit (HEO) satellites. Based on the test results, it was confirmed that the prototype of the tracking mount and controller of the ARGO-M could achieve the required repeatability along with a tracking accuracy of less than 1 arcsec.     

基于KS函数的协同优化算法及其应用

多学科设计优化(MDO)是当前航空航天复杂系统设计研究中一个最新、最活跃的领域,针对多学科设计优化中协同算法优化过程中存在的收敛困难、计算量大、费时等问题,提出一种新的系统级约束处理方法,利用KS函数的凝聚特性,将系统级的多个学科约束凝聚成一个拥有光滑高阶可微的可行域单约束,来取代罚函数法中的多个约束,以缓解多约束之间的冲突并加速收敛速度.利用两个典型算例进行测试,结果表明改进方法有效.     

机场竞争力评价指标体系的构建

本文首先分析总结了机场竞争力的形成机理,在此基础上提出了机场竞争力的评价原则,最后,构建了一套包含4个一级指标、16个二级指标和41个三级指标的机场竞争力评价指标体系,旨在通过这套评价体系对机场的竞争力发展水平进行评估,找出机场竞争力发展过程中的优势不足,为机场在市场竞争中提高竞争力水平和核心竞争力提供科学的参考依据.     

CICC型超导导体外壳制作工艺研究

通过焊接参数的选定(焊接电流 I=150A,电压U=8.8V,焊接速度0.7～1m/min),保证单根导体长度不小于300m,焊缝无气孔,裂纹等焊接缺陷.使焊接后的CICC超导导体内部最接近焊缝位置的温度低于183℃,确保导体导电性能,导体焊缝耐压试验不低于5MPa,且氦气密性能良好,研制出的产品满足相关技术标准的质量...     

广汉机场雷暴的航空气候特征分析

利用1986-1995年十年的地面观测资料,对广汉机场雷暴的年变化、日变化特征及持续时间特点进行了分析,同时分析了产生雷暴的天气系统及环流形势。     

FeS/S/FeS(2) redox system and its oxidoreductase-like chemistry in the iron-sulfur world

The iron-sulfur world (ISW) theory is an intriguing prediction regarding the origin of life on early Earth. It hypothesizes that life arose as a geochemical process from inorganic starting materials on the surface of sulfide minerals in the vicinity of deep-sea hot springs. During the last two decades, many experimental studies have been carried out on this topic, and some interesting results have been achieved. Among them, however, the processes of carbon/nitrogen fixation and biomolecular assembly on the mineral surface have received an inordinate amount of attention. To the present, an abiotic model for the oxidation-reduction of intermediates participating in metabolic pathways has been ignored. We examined the oxidation-reduction effect of a prebiotic FeS/S/FeS(2) redox system on the interconversion between several pairs of α-hydroxy acids and α-keto acids (i.e., lactate/pyruvate, malate/oxaloacetate, and glycolate/glyoxylate). We found that, in the absence of FeS, elemental sulfur (S) oxidized α-hydroxy acids to form corresponding keto acids only at a temperature higher than its melting point (113°C); in the presence of FeS, such reactions occurred more efficiently through a coupled reaction mechanism, even at a temperature below the phase transition point of S. On the other hand, FeS was shown to have the capacity to reversibly reduce the keto acids. Such an oxidoreductase-like chemistry of the FeS/S/FeS(2) redox system suggests that it can determine the redox homeostasis of metabolic intermediates in the early evolutionary phase of life. The results provide a possible pathway for the development of primordial redox biochemistry in the iron-sulfur world. Key Words: Iron-sulfur world-FeS/S/FeS(2) redox system-Oxidoreductase-like chemistry. Astrobiology 11, 471-476.     

关注教师职业压力预防教师职业枯竭

教师的职业压力是当前教育界必须正视和亟待解决的问题。职业压力导致教师出现不稳定的情绪和不健全的心理,使教师消极行为及生理疾病增多,损害教师的身体健康。其职业压力来源于职业角色、学生和教师本身。要应对职业压力,预防职业枯竭,全社会都要做出努力。     

谈莫斯科对俄、中军事演习的不同看法

最近俄国媒体在一报道中表示，对俄、中军事演习的宣布，在俄国内、外造成极大震憾，尽管近年俄中关系密切，但俄罗斯并无必要为中国而涉足亚太地区，特别是台海的安全问题，况且俄、中两国历史矛盾的阴影还未彻底削除。此外，近年中国的迅速崛起，也引起俄罗斯的注意。     

保持知识战斗力领先之钥：精进台湾军事刊物刍议

两军对垒比的不仅是双方的物质条件（如装备或兵力的质量与数量），也是双方军事战略与用兵思想的试炼。战史上有太多的例子，居物质条件优势的一方，往往因为战略思想的不如对方，而无法克敌甚至输掉战争。第一次世界大战，英国陆、海军部是因为思想上的僵化，前者使得几近一个世代的英伦子弟平白填身沟壑，而无任何明显的战果，后者使得一个原本具有数量与情报优势及纳尔逊式攻击精神的舰队竟然会在日德兰海战中扑空，自丧提早结束战争的契机。     

The heart-shaped supernova remnant 3C 391 viewed in multi-bands

Using Chandra X-ray, Spitzer mid-IR, and 1.5 GHz radio data, we examine the spatial structure of SNR 3C 391. The X-ray surface brightness is generally anti-correlative with the IR and radio brightness. The multiband data clearly exhibit a heart-shaped morphology and show the multi-shell structure of the remnant. A previously unseen thin brace-like shell on the south detected at 24 μm is projected outside the radio border and confines the southern faint X-ray emission. The leading 24 μm knot on the SE boundary appears to be partly surrounded by soft X-ray emitting gas. The mid-IR emission is dominated by the contribution of the shocked dust grains, which may have been partly destroyed by sputtering.