光学采样成像系统传递函数补偿的试验研究

简要介绍了传递函数补偿(MTFC)验证试验,通过物理仿真和基于ISO20462的最小可觉差(JND)主观评价,对光学采样成像系统MTFC进行了研究。在实验室建立模拟采样成像系统进行物理仿真;通过对7次JND评价数据之间的相互验证,说明JND主观评价具有客观性,试验数据和MTFC验证结论准确可信。     

Enhancement and Validation of the IDES Orbital Debris Environment Model

Orbital debris environment models are essential in predicting the characteristics of the entire debris environment, especially for altitude and size regimes where measurement data is sparse. Most models are also used to assess mission collision risk. The IDES (Integrated Debris Evolution Suite) simulation model has recently been upgraded by including a new sodium–potassium liquid coolant droplet source model and a new historical launch database. These and other features of IDES are described in detail. The accuracy of the IDES model is evaluated over a wide range of debris sizes by comparing model predictions to three major types of debris measurement data in low Earth orbit. For the large-size debris population, the model is compared with the spatial density distribution of the United States (US) Space Command Catalog. A radar simulation model is employed to predict the detection rates of mid-size debris in the field of view of the US Haystack radar. Finally, the small-size impact flux relative to a surface of the retrieved Long Duration Exposure Facility (LDEF) spacecraft is predicted. At sub-millimetre sizes, the model currently under-predicts the debris environment encountered at low altitudes by approximately an order of magnitude. This is because other small-size debris sources, such as paint flakes have not yet been characterised. Due to the model enhancements, IDES exhibits good accuracy when predicting the debris environment at decimetre and centimetre sizes. Therefore, the validated initial conditions and the high fidelity future traffic model enables IDES to make long-term debris environment projections with more confidence.     

固体发动机压强-时间曲线中燃烧时间的确定

以固体推进剂燃烧公式为基础，采用计算力学中的数值积分及插值法，并利用计算机技术，研究了用燃烧室药柱的实际肉厚，确定固体火箭发动机试验曲线中燃烧时间的新方法，在点火发动机中应用的结果表明，此方法解决了试验曲线数据处理结果散布范围较大的问题，提高了燃速预估的准确性。     

螺旋弹簧应力松弛实验研究

对导弹弹体及发动机中常用的压缩螺旋弹簧进行了应力松弛实验研究,得到了这种弹簧在常温下长期贮存中的应力松弛方程,为导弹武器系统的质量评判和延寿提供了可靠的实验依据。     

绕平板上直圆柱体的高超声速湍流分离流

本文给出直圆柱上游中心线上壁面压力和热流特性及其分离激波运动的特征参数。试验条件是:自由流马赫数为7.8和5,单位长度雷诺数为3.5×10~7/米和4.7×10~7/米。结果表明:1.直圆柱上游中心线上的流场是一个有二次分离的流场,平均壁面压力分布呈双峰型,平均热流分布略有不同,出现一近似平台区,但在分离激波上游影响起始区域和直圆柱前缘邻近区域(x/D<0.5),两者变化极其相似。来流马赫数愈高,分离激波在中心线上的上游影响区长度和峰压及峰热值愈大。2.分离激波是极其不稳定的,出现大尺度低频运动,激波流向运动尺度约0.5D,振荡频率主要集中在2.5kHz以下。     

“中华卫星一号”及其海洋水色成像仪

介绍了中国台湾研制的“中华卫星一号”（ＲＯＣＳＡＴ－１）实验卫星的概况。较详细介绍该卫星上的海洋水色成像仪的构成、主要性能。给出了“中华卫星一号”及其海洋水色成像仪外形图和结构图。     

深化教学改革提高教学质量培养高素质技术应用性人才——西安航专教学改革与创新实践

为进一步推动陕西高职教育事业健康发展，在充分调查研究的基础上，对西安航专高职教育教学改革进行总结、分析，着重论述了西安航专教学改革的指手思想、主要目标、基本思路、主要做法及教学改革的主要成果。     

Gamma Astrometric Measurement Experiment (GAME) – Implementation and performance

The GAME mission concept is aimed at testing the General Relativity, through precise measurement of the gravitational deflection of light by the Sun, by means of an optimised telescope operating in the visible and launched in orbit on a small class satellite. We describe the proposed mission profile, the preliminary payload design and the expected performance. The targeted precision on the γ parameter of the PPN formulation of General Relativity is in the range 10⁻⁶ to 10⁻⁷. The measurement principle relies on the differential astrometric signature on the stellar positions. The instrument concept is based on a dual field, multiple aperture Fizeau interferometer, observing simultaneously two sky regions close to the solar limb. A beam combiner folds the telescope line of sight on two different directions on the sky, separated by a base angle of 4°. The diluted optics approach achieves an efficient rejection of the scattered solar radiation, while retaining an acceptable angular resolution on the science targets.     

浅谈新形势下的高等职业教育实验教学改革

通过阐述高职教育开放式实验教学的特征和实施原则，指出了开放式实验教学的培养要求和培养目标。开放式实验教学并不是指实验室课外时间对学生简单的开放，而是在实验实训环节中，充分体现学生的主体地位，自己独立选择、设计命题并实施完成，以促进学生对理论知识应用与理解。     

格栅湍流场风参数沿风洞轴向变化规律

格栅湍流场常用于各类风洞试验中,桥梁断面气动参数均与来流风参数有关。对不同格栅湍流场下的风参数沿风洞轴向变化的规律进行了研究,得出风参数主要与测点与格栅断面间距、格栅板条厚度和单元格栅边长有关。随着间距增加,平均风速短期内急剧衰减,然后趋于稳定。随着间距增加,来流湍流的总能量减小而主要能量迁移至高频区域:湍流度呈指数衰减,湍流积分尺度呈增长趋势;约化风谱形状保持相似,峰值对应约化频率值基本保持不变,但峰值变小。另外根据风参数的变化规律,调试出2类特定的湍流场参数:湍流度相似而湍流积分尺度不同的湍流场和湍流积分尺度相似而湍流度不同的湍流场,以便于详尽研究主要风参数对桥梁断面气动参数的影响。