一种新型恒温—温补晶体振荡器

提出了一种ＯＣＸＯ的恒温控制方法。该方法是利用乙醇的沸点制成换态式恒温箱。这种温度控制方法既可以用作中准确度的ＯＣＸＯ，又可以作为精密双层控温ＯＣＸＯ的外层恒温装置，还可以与简单的温补线路结合，构成高准确度的ＯＴＣＸＯ。     

对地观测卫星姿态非线性控制方法

针对对地观测卫星姿态控制系统 ,着重考虑干扰、噪声对卫星姿态稳定度的影响。忽略耦合和挠性部件影响 ,也不考虑敏感器和执行机构的动态特性 ,针对卫星定向模式的主调节器设计问题构造了一种简单实用的非线性控制器 ,并分析和验证了该非线性控制器的有效性。     

利用平滑约束复原方法处理CCD相机遥感图像

重点研究了频域平滑约束复原方法以及该方法对遥感领域中的实际应用，文章先介绍了平滑约束复原方法的理论基础，然后用该方法对CCD相机的遥感图像进行了复原处理，讨论了遥感器系统调制传递函数（MTF）曲线的拟合，遥感器系统MTF矩阵的构造以及复原参数的选择。可以得出结论，在一定条件下，利用平滑约束复原方法可以有效地改善整个系统的调制传递函数，从而使图像变得清晰。     

双独立闭环复合液压伺服控制体系的分析

针对现有几种液压伺服控制系统的优缺点,基于高性能和节能这一发展趋势,提出基于伺服电机、定量泵、蓄能器和伺服阀的双独立闭环的新型复合控制体系.分析了其结构特点,建立了数学模型并进行了仿真分析和实验验证,证明新型控制体系充分发挥了各个控制环节的效能,实现了流量适应,较现有的控制方案简单可靠,在综合指标方面有了很大的提高,适合机载液压系统和弹载液压系统.      

平面工艺功率型半导体晶体管铝迁移实验

在平面工艺制造的功率型半导体晶体管芯片表面,发现高强度电场条件下存在跨越0.05 mm半绝缘硅带的铝迁移现象,对此开展了一系列实验研究. 通过开帽物理观察与分析、低温测试与烘干验证、迁移物质分析对比,确定了迁移现象中的迁移物质,同时分别取证环境温度、湿度、芯片表面污染物以及器件局部结构与此迁移现象的关联性,以此提出了迁移机理假说,为在不同的诱发条件下对此迁移机理进行确认和量化研究提供指导.      

Electron density inversed by plasma lines induced by suprathermal electron in the ionospheric modification experiment

Incoherent scatter radar (ISR) is the most powerful ground-based measurement facility to study the ionosphere. The plasma lines are not routinely detected by the incoherent scatter radar due to the low intensity, which falls below the measured spectral noise level of the incoherent scatter radar. The plasma lines are occasionally enhanced by suprathermal electrons through the Landau damping process and detectable to the incoherent scatter radar. In this study, by using the European Incoherent Scatter Association (EISCAT) UHF incoherent scatter radar, the experiment observation presents that the enhanced plasma lines were observed. These plasma lines were considered as manifest of the suprathermal electrons generated by the high-frequency heating wave during the ionospheric modification. The electron density profile is also obtained from the enhanced plasma lines. This study can be a promising technique for obtaining the accurate electron density during ionospheric modification experiment.     

高精度激波捕捉格式的性能分析

在数值模拟激波-湍流干扰问题时,为了精确模拟湍流脉动的小尺度结构,数值格式应尽量减小自身的数值耗散.但是为了稳定、无震荡地捕捉激波,数值格式又必须具有一定程度的数值耗散.基于上述这2种相互矛盾的要求,采用无黏泰勒格林涡、可压缩湍流等经典算例对目前广受好评的几种高精度格式进行了系统地对比.一系列的计算分析表明,当前工程中广泛应用的高精度格式虽然都能一定程度地满足上述2种要求,但与理想目标仍有较大的差距.     

Chaboche随动硬化模型参数确定及棘轮效应

采用遗传算法确定不同Chaboche随动硬化模型的参数,得到的3种模型中,四分量模型对棘轮的预测与试验结果符合最好.增大应力幅值或应力平均值,都会使应变峰值增大,应变累积速度加快;利用确定的四分量模型研究加载顺序对棘轮的影响.结果表明,平均应力加载顺序对棘轮预测有较大影响,加载顺序高-低的累积应变低于加载顺序低-高的累积应变,而且先加载的平均应力越大,后加载的载荷产生的累积应变越小;而应力幅值加载顺序对应变累积几乎没有影响.     

Optimum parameter matching obtained by experiments for coring drilling into lunar simulant

This paper performs a series of ground experiments (on the Earth) to obtain optimum parameter matching for a future core drill on the Moon. Three common stages, I, II, III, are recognized with respect to the cut per revolution (CPR), which is defined as the ratio between the feeding speed and the rotating speed. The optimum matching between the feeding speed and the rotating speed for drills locates at the boundary position between Stage II and Stage III, where the coring rate saturates and the weight on the bit and the driving torque are still low. Further data analysis of the ground experiments reveals that the optimum matching signifies a proportional relation between the maximum conveying rate (MCR) by the groove of the auger and its rotating speed. The kinetic analysis in an ideal condition without gravity, the friction from the auger groove and the pressure at the bit confirm a similar proportion. The correlation between the proportions needs further study to determine whether the optimum matching obtained on the ground can be directly applied to future drills on the Moon.