企业并购过程中的产权制度约束及其对策

企业并购作为存量资源重组的重要形式，其效应已在经济体制改革过程中逐渐显现出来，但是，一个严重缺陷－－产权制度约束，正在成为我国企业并购市场化进程的主要障碍。作者针对目前企业并购的产权制度问题，提出适应炮国企业并购的制度安排和政策建议。     

Compact antennas for UWB applications

A report on an investigation of spherical, disc, and half-disc antennas in the frequency and time domains with the objective of developing small planar versions of the antennas. These antennas have an omni-directional impulse response in azimuth and pulse duration of 0.5-0.65 nanoseconds. In addition, the measured data show a reasonable peak received signal in a pulse communication link using two identical antennas.     

俯仰三角翼的流态及结构

本文对俯仰三角翼的流动特性进行了实验研究，给出了俯三角翼的截面流态特点，对三角翼俯仰 运动的流动机理进行了分析。     

Evolution of salt finger convection with steady wind shear

In oceanographics situations where salt fingers may be an important mechanism for the transport of heat and salt in the vertical direction, velocity shears may also be present. Salt finger convection is analogous to Bénard convection in that the kinetic energy of the motions is obtained from the potential energy stored in the unstable distribution of a stratifying component. On the basis of the thermal analogy it is of interest to discover whether salt fingers are converted into two-dimensional sheets by wind shear, and how the vertical fluxes of heat and salt are changed by wind shear. Salt finger convection under the effect of steady wind shear is theoretically examined in this paper. The evolution of instability developing in the presence of a vertical density gradient disturbance and the horizontal Couette flow is considered near the onset of salt fingers under a moderate rate of shear. We use velocity as the basic variable and solve the pressure Poisson equation in terms of the associated Green function. Growth competition between the longitudinal rolls (LR) and the transverse rolls (TR), whose axes are, respectively, in the direction parallel to and perpendicular to the Couette flow, is investigated by the weakly nonlinear analysis of coupled-mode equations. The results show that the TR mode is stable under a small wind shear and the LR mode is stable for a higher wind shear.     

Grasping Strategy in Space Robot Capturing Floating Target

When the space robot captures a floating target, contact impact occurs inevitably and frequently between the manipulator hand and the target, which seriously impacts the position and attitude of the robot and grasping security. “Dynamic grasping area” is introduced to describe the collision process of manipulator grasping target, and grasping area control equation is established. By analyzing the impact of grasping control parameters, base and target mass on the grasping process and combining the life experience, it is found that if the product of speed control parameter and dB adjustment parameter is close to but smaller than the minimum grasping speed, collision impact in the grasping process could be reduced greatly, and then an ideal grasping strategy is proposed. Simulation results indicate that during the same period, the strategy grasping is superior to the accelerating grasping, in that the amplitude of impact force is reduced to 20%, and the attitude control torque is reduced to 15%, and the impact on the robot is eliminated significantly. The results would have important academic value and engineering significance.     

复杂可修系统效能中可信度矩阵的构造方法

复杂可修系统可信度建模对保证效能的定量分析至关重要.本文在考虑不同维修状况的基础上,着重对不同任务剖面内相应任务阶段中武器装备可信度进行了深入的定量分析和综合,进而构造出武器装备的可信度矩阵,用于武器装备的效能分析;文中以某地面车辆为例,进一步论证了武器装备可信度矩阵的工程含义,旨在为合理确定一大类武器装备的效能和可信度指标提供理论依据.     

考虑轨道摄动的外热流计算分析

为改进传统外热流算法未考虑外热流经多次反射后的吸收和国外商业软件未考虑轨道摄动及太阳矢量变化对外热流的影响等不足,重新定义了外热流角系数和外热流辐射传递因子,综合SGP4轨道模型和Gebhart方法,给出了考虑摄动等因素的辐射传递因子和轨道外热流计算模型,以及相应的计算流程。通过仿真分析论证了考虑多次反射及摄动等因素的重要性。     

小波技术在组合导航系统故障诊断中的应用

针对组合导航系统中存在的故障类型和特点，提出一种新的基于信号处理的故障检测方法。该方法利用小波分析技术对含有故障信息的系统信号进行分析处理，并将此方法应用于SINS／GPS组合导航系统。仿真结果分析表明，小波分析技术能很好地及时检测出组合导航系统的硬故障，且更加简便灵活，从而可以将小波分析技术应用于组合导航系统的故障检测。     

基于模型的载人航天器研制方法研究与实践

载人航天器具有系统规模大、技术难度高、单件小批量、无法通过多次飞行持续完善设计、可靠性要求高等特点。当前载人航天器研制中仍存在着参数化和模型化程度不高、基于模型的系统综合仿真验证不足、研制各环节缺乏数字化集成等问题，传统基于文本的系统工程方法已无法满足研制需求，亟需采用基于模型的系统工程方法。本文针对载人航天器的研制现状和应用需求，提出了面向载人航天器全生命周期的模型体系，定义了需求模型、功能模型、产品模型、工程模型、制造模型、实做模型等六类模型，提出了基于模型的研制流程，包含系统设计闭环验证、产品设计闭环验证、实做产品闭环验证3个验证环节，并深入探索了各研制环节中不同模型间的传递与关联关系。以某型号载人航天器为应用基础，系统地验证了提出的方法。     

新型单元的频率选择表面

在传统十字单元基础上,提出一种新型单元的频率选择表面(FSS)。分析传统十字单元FSS和新型单元FSS在大角度入射时的极化稳定性,并研究TM波入射角度变化时,中心频率的漂移及传输系数的变化。结果表明,传统十字单元FSS在45°入射时中心频率的极化稳定性很差,漂移量为406MHz,TM波由0°到45°入射时,中心频率漂移为448MHz;而新型单元FSS具有中心频率的角度稳定性,TM波入射角度由0°变到45°时,中心频率漂移量仅为28MHz,并且在大角度入射时具有中心频率极化稳定性。