用激光干涉技术测量转速的研究

叙述了一种新型转速激光干涉测量方法,详细分析了这种方法的工作原理,确定了本测量方法的转速测量范围,给出了实验结果。     

先进的宇航试验舱温控系统

介绍了中国新一代宇航试验舱的温控系统。该温控系统设计思想先进、结构新颖。在直径２．３ｍ,长２ｍ的封闭舱体控温面上,实现了０℃～５０℃的任意温度定点控制及９０ｍｉｎ内的正弦波、梯形波、三角波的周期变化;在整个控温面上温度非均匀性（均方根偏差）小于０．３℃,远远超过了非均匀度±１℃、控制精度±２℃的原设计指标。     

小型磁偏转质谱计性能实验研究

自主研发了小型磁偏转质谱计,并对其质量范围、分辨本领、灵敏度和最小可检分压力四个主要性能指标进行了实验测试和比对。结果表明,该质谱计的质量范围为（1~143）amu,相对N₂的分辨本领为1400,灵敏度为4.2×10^-5 A/Pa,最小可检分压力为9.5×10^-7 Pa。该测试和比对结果为磁偏转质谱计进一步的优化设计和性能提高奠定了重要基础。     

APPLICATION OF HOT PRESS SINTERING TECHNIQUE TO EXPLOSIVE CHARGE LINER OF PETROLEUM PERFORATION BULLET

介绍了一种制备石油射孔弹的药形罩的新方法,采用粉末冶金技术,热压烧结工艺制备石油射孔弹的药形罩,并对药形罩的烧结工艺进行了研究。实验结果表明,采用该工艺制备的石油射孔弹药形罩可以满足要求。     

GRACE gravity field modeling with an investigation on correlation between nuisance parameters and gravity field coefficients

The GRACE (Gravity Recovery And Climate Experiment) monthly gravity models have been independently produced and published by several research institutions, such as Center for Space Research (CSR), GeoForschungsZentrum (GFZ), Jet Propulsion Laboratory (JPL), Centre National d’Etudes Spatiales (CNES) and Delft Institute of Earth Observation and Space Systems (DEOS). According to their processing standards, above institutions use the traditional variational approach except that the DEOS exploits the acceleration approach. The background force models employed are rather similar. The produced gravity field models generally agree with one another in the spatial pattern. However, there are some discrepancies in the gravity signal amplitude between solutions produced by different institutions. In particular, 10%–30% signal amplitude differences in some river basins can be observed. In this paper, we implemented a variant of the traditional variational approach and computed two sets of monthly gravity field solutions using the data from January 2005 to December 2006. The input data are K-band range-rates (KBRR) and kinematic orbits of GRACE satellites. The main difference in the production of our two types of models is how to deal with nuisance parameters. This type of parameters is necessary to absorb low-frequency errors in the data, which are mainly the aliasing and instrument errors. One way is to remove the nuisance parameters before estimating the geopotential coefficients, called NPARB approach in the paper. The other way is to estimate the nuisance parameters and geopotential coefficients simultaneously, called NPESS approach. These two types of solutions mainly differ in geopotential coefficients from degree 2 to 5. This can be explained by the fact that the nuisance parameters and the gravity field coefficients are highly correlated, particularly at low degrees. We compare these solutions with the official and published ones by means of spectral analysis. It is found that our solutions are, in general, consistent with others in the spatial pattern. The water storage variations of the Amazon, Chari and Ganges river basins have also been computed. The variations computed with the NPARB approach are closer to those produced by JPL and DEOS solutions, while the variations produced with the NPESS approach are in good agreement with those produced by the CSR and GFZ solutions. A simulation study is implemented with considering realistic noise and low-frequency error. The two approaches are used to recover the true model. The NPESS solution appears closer to the true one. Therefore we are inclined to estimate the nuisance parameters simultaneously with the geopential coefficients.     

Conceptual design of a bioregenerative life support system containing crops and silkworms

This article summarizes a conceptual design of a bioregenerative life support system for permanent lunar base or planetary exploration. The system consists of seven compartments – higher plants cultivation, animal rearing, human habitation, water recovery, waste treatment, atmosphere management, and storages. Fifteen kinds of crops, such as wheat, rice, soybean, lettuce, and mulberry, were selected as main life support contributors to provide the crew with air, water, and vegetable food. Silkworms fed by crop leaves were designated to produce partial animal nutrition for the crew. Various physical-chemical and biological methods were combined to reclaim wastewater and solid waste. Condensate collected from atmosphere was recycled into potable water through granular activated carbon adsorption, iodine sterilization, and trace element supplementation. All grey water was also purified though multifiltration and ultraviolet sterilization. Plant residue, human excrement, silkworm feces, etc. were decomposed into inorganic substances which were finally absorbed by higher plants. Some meat, ingredients, as well as nitrogen fertilizer were prestored and resupplied periodically. Meanwhile, the same amount and chemical composition of organic waste was dumped to maintain the steady state of the system. A nutritional balanced diet was developed by means of the linear programming method. It could provide 2721 kcal of energy, 375.5 g of carbohydrate, 99.47 g of protein, and 91.19 g of fat per capita per day. Silkworm powder covered 12.54% of total animal protein intakes. The balance of material flows between compartments was described by the system of stoichiometric equations. Basic life support requirements for crews including oxygen, food, potable and hygiene water summed up to 29.68 kg per capita per day. The coefficient of system material closure reached 99.40%.     

高性能混凝土的外加剂优化研究(英文)

运用不同减水剂和早强剂配制高性能混凝土(High performance concrete,HPC),测定其工作性、标准养护强度和蒸汽养护强度,研究了HPC的外加剂选用原则。结果表明,掺加聚缩酸系高效减水剂有利于HPC获得高工作性和高强度。硫酸钠早强剂将导致工作性不好,强度降低。对于蒸汽养护的HPC制品,应该优先采用硫酸钠含量低的萘系高效减水剂。因此,HPC外加剂的选择应该考虑养护条件的差异。     

《客舱服务技能》课程教学的改进与思考

《客舱服务技能》是空乘专业的一门专业必修课程。在课程改革中,如何改进《客舱服务技能》的教学效果是我们需要关注的重点。本文从目前该课程发展状况、师资、教材、实训条件、教学方法等方面对该课程的建设情况及存在的问题进行了分析与探讨。     

基于遗传算法的无人机协同侦察航路规划

无人机将成为侦察卫星、有人驾驶侦察机的重要补充与增强手段 ,成为未来战场上广泛应用的一种侦察工具。为了提高无人机 (UAV)的侦察效率 ,在执行侦察任务前必需规划设计出高效的无人机侦察飞行航路。针对这一问题 ,本文提出了一种侦察效率指标评估的计算方法 ,解决了航路规划中的侦察效率量化问题。考虑在大范围任务区域内进行侦察航路优化存在计算的复杂性和收敛性等问题 ,本文采用遗传算法对侦察航路进行了优化处理。通过该方法得到的侦察航路可以有效地提高无人机的侦察效率。     

热阻塞与燃烧不稳定性问题的试验研究

在某型涡扇发动机加力燃烧室试验过程中,曾出现过一种燃烧不稳定性,频率为106Hz,其声振频率与一阶纵向振频计算值基本相符。经分析计算表明这是一种气柱振荡不稳定性。原来,在等截面通道中加热时,总压因热阻增大而下降,静压则由于总压下降和比容的增加而急剧降低。