智能控制大功率氨压机制冷系统

本文将模糊控制、神经元控制等智能控制技术成功地应用于大型活塞式氨压机制冷系统，实现了恒转矩负载的变频调速节能。实际运行结果证明，该智能控制的大功率氨压机制冷系统工作稳定、控制精度高、节能效果显著，具有很好的经济效益及推广应用价值。     

一种组合自适应模糊控制方法及其在月球探测车上的应用

自适应模糊控制是解决不确知非线性系统问题的一种有效手段。文中以月球探测车的驱动控制为背景,针对这类非线性MIMO系统,提出一种组合自适应模糊控制方法,用于系统模型不能准确获知的情形。在本方法中,控制律由3部分组成:监督控制项、跟踪控制项和补偿控制项。在控制律的设计中,通过自适应项来同时补偿模糊逻辑系统的逼近误差以及外部干扰的影响,且无需假设模糊逻辑系统最小逼近误差的上确界已知。基于Lyapunov方法,证明了闭环系统是全局稳定的,系统输出误差渐近收敛。将该方法应用于月球探测车的驱动控制中,仿真结果表明了方法的有效性。     

最少燃料消耗的固定推力共面轨道变轨研究

本文研究了推力固定条件下，从圆轨道进入共面圆轨道一次入轨最节省燃料的推力方向控制策略。这类问题都可归结为两点边值问题，对自由初值的选取作了讨论，并采用打靶法迭代求解。计算了从停泊轨道到同步转移道以及两个过地圆轨道之间的最优转移，获得满意的结果。     

自适应天线互耦影响研究

用等效网络法推导了考虑互耦影响时阵列的输出信号解析式和信噪比,仿真了不同阵元间距时,自适应直线阵的方向图和输出信噪比,得到了一些有用的结论。     

空间辐射散热器含液滴介质的辐射特性和辐射传热

本文从米氏电磁散射理论出发，计算了含液滴介质的辐射特性。考察了中向同性散射能量传递份额的再分配，导出了吸收、发射、各几同性散射介质的辐射传递系数。计算了空间辐射散热器液滴层瞬态辐射换热，经与文献［４，５］的比较表明，本文所导出的辐射传递系数计算方法正确，精度高。用计算机辅助实验，分析液滴发生器产生粒子的大小、粒径分布对瞬态辐射换热的影响，可减少空间辐射散热器设计过程中的实验次数。     

封头补强技术研究

研究了碳纤维／环氧复合材料φ１５０ｍｍ和φ４８０ｍｍ压力容器封头的局部补强方法和工艺，试验结果表明：φ４８０ｍｍ压力容器经在大金属件边缘补强后改变了水压爆破时金属件飞出的现象，纤维强度得以充分发挥而使筒身段纵环向同时破坏；φ１５０ｍｍ压力容器的应力平衡系数可由０．７５提高到０．８５以上，筒身段纵向纤维发挥强度由２０９０ＭＰａ提高到２３３６ＭＰａ，提高约１１．８％。由此可见，壳体铺层设计与封头补强巧妙地结合是壳体优化设计的重要方法，是充分发挥纵向纤维强度的有效措施。     

Changes in organ perfusion and weight ratios in post-simulated microgravity recovery

Head-down tilt models have been used as ground-based simulations of microgravity. Our previous animal research has demonstrated that there are significant changes in fluid distribution within 2 h after placement in a 45 degrees head-down tilt (45HDT) position and these changes in fluid distribution were still present after 14 days of 45HDT. Consequently, we investigated changes in fluid distribution during recovery from 16 days of 45HDT. Changes in radioactive tracer distribution and organ/body weight ratio were examined in rats randomly assigned to a 45HDT or prone control group. The 45HDT rats were suspended for 16 days and then allowed to recover at the prone position 0, 77, 101, or 125 h post-suspension. Animals were injected with technetium-labeled diethylenetriamine pentaacetate (99mTcDTPA, MW=492 amu, physical half-life of 6.02 h) and then killed 30 min post-injection. Lungs, heart, liver, spleen, kidneys, and brain were harvested, weighed, and measured for radioactive counts. Statistical analyses included two-way analysis of variance (ANOVA) that compared 45HDT versus controls at the four experimental time points. The organ weight divided by the body weight ratio for the brain, heart, kidneys and liver in the 45HDT rats was significantly different than the control rats, regardless of time (treatment). There was no difference between the different time points (time). The average 99mTcDTPA count divided by the organ weight ratio values for the heart, liver, and spleen were significantly higher in the 45HDT group than the control group. The average counts for the heart and spleen were significantly higher at 77, 101, and 125 h than at time zero. We conclude that the major organs have different recovery patterns after 45HDT for 16 days in the rat.