地地战术导弹子母弹抛射与散布建模仿真

基于对子弹的抛射和末端弹道的物理过程建模进行了仿真计算,研究了各层子弹抛射速度、抛射延时给子弹分布带来的影响。结果表明,通过适当调整母弹弹道、抛射延时等参数,可以有效提高子母弹的覆盖面积。     

高性能隔离分配放大器的研制

论述了现代精密时频系统对隔离分配放大器的技术要求及其重要作用.介绍了为改进我台守时系统标准频率分配子系统而研制的一个高性能隔离分配放大器.对于5 MHz信号,该分配放大器的反向隔离度和路间隔离度均优于115 dB(5 MHz);相位噪声在1 Hz达到-135 dBc/Hz;噪声本底为150 dBc/Hz;插入秒稳损失达到10-13量级.在13 dBm输出情况下,谐波小于-40 dBc.对该分配放大器主要性能测试涉及的测量方法也作了介绍.     

中小企业产业投资基金的逆向选择问题分析

主要研究在信息不对称条件下,从产业投资基金管理人的角度出发,利用模型证明中小企业的逆向选择行为会影响产业投资基金的运作,进而为基金管理人提出解决逆向选择问题的建议和策略。     

Clusters of Galaxies: Setting the Stage

Clusters of galaxies are self-gravitating systems of mass ∼10¹⁴–10¹⁵ h ⁻¹ M_⊙ and size ∼1–3h ⁻¹ Mpc. Their mass budget consists of dark matter (∼80%, on average), hot diffuse intracluster plasma (≲20%) and a small fraction of stars, dust, and cold gas, mostly locked in galaxies. In most clusters, scaling relations between their properties, like mass, galaxy velocity dispersion, X-ray luminosity and temperature, testify that the cluster components are in approximate dynamical equilibrium within the cluster gravitational potential well. However, spatially inhomogeneous thermal and non-thermal emission of the intracluster medium (ICM), observed in some clusters in the X-ray and radio bands, and the kinematic and morphological segregation of galaxies are a signature of non-gravitational processes, ongoing cluster merging and interactions. Both the fraction of clusters with these features, and the correlation between the dynamical and morphological properties of irregular clusters and the surrounding large-scale structure increase with redshift. In the current bottom-up scenario for the formation of cosmic structure, where tiny fluctuations of the otherwise homogeneous primordial density field are amplified by gravity, clusters are the most massive nodes of the filamentary large-scale structure of the cosmic web and form by anisotropic and episodic accretion of mass, in agreement with most of the observational evidence. In this model of the universe dominated by cold dark matter, at the present time most baryons are expected to be in a diffuse component rather than in stars and galaxies; moreover, ∼50% of this diffuse component has temperature ∼0.01–1 keV and permeates the filamentary distribution of the dark matter. The temperature of this Warm-Hot Intergalactic Medium (WHIM) increases with the local density and its search in the outer regions of clusters and lower density regions has been the quest of much recent observational effort. Over the last thirty years, an impressive coherent picture of the formation and evolution of cosmic structures has emerged from the intense interplay between observations, theory and numerical experiments. Future efforts will continue to test whether this picture keeps being valid, needs corrections or suffers dramatic failures in its predictive power.     

分布式电能计量与计费系统中通信信道特性与实现方案的研究

本文介绍了分布式电能计量与计费系统中低压电力线作为载波通信信道时的信道特性，给出了实验数据和特性曲线，并选择了通信的基本方案。     

生产关系就是分配关系

在马克思的著作中对生产关系的论述本来是清楚的、明确的，牛产关系和分配关系是不可分割的统一体，它们构成了一定社会的生产方式。把生产关系定义为三因素的观点是理论开倒车的行为。     

离心力场下多孔介质中热驱动换热的实验

以涡轮叶片新型超级冷却技术的研究为背景,在具有冷却通道的新型冷却结构中加入多孔介质,用实验的方法,模拟了离心力场下该新型冷却结构的热驱动换热现象,并与无多孔介质的情况进行了比较。实验结果表明:随着旋转速度、热流密度和冷气进口速度的增大,装有多孔介质的新型冷却结构的热驱动换热能力逐渐增强。同时实验研究发现,加入多孔介质后该新型冷却结构比未加多孔介质时具有更好的换热效果。      

SH波对结构表面上含有多个半圆形介质夹杂的散射

利用复变函数和多极坐标系的方法,研究了在结构表面上含有多个半圆形介质夹杂的散射问题,首先给出 SH波对多个半圆形介质夹杂的散射波函数,并利用多极坐标系的方法,来满足介质界面上的连续条件和表面上的边界条件,归结为对一组无穷代数方程组的求解,简化了问题的求解。作为算例,对结构水平面上含有 2个半圆形夹杂介质进行分析,并讨论了夹杂介质参数的变化及孔距对位移的影响。     

再论光学铅垂对点锥面理论与垂准仪的室内校准法

深入思考了垂准仪校准的若干问题,从光学铅垂对点锥面理论出发,就垂准仪校准中的基础理论、实际校准及校准装置的建立等方面阐述了自己的见解。     

粗糙表面偏振二向反射特性建模方法研究

针对地面目标光学偏振特性预测对基础材质粗糙表面偏振二向反射特性建模的需求,对比分析国内外常用的经验、物理和半经验等3种偏振二向反射分布模型的优缺点及其适用范围,得出半经验模型更适用于地面目标光学偏振特性预测.在此基础上,研究基于半经验Priest-Gemer模型的参数反演方法,并提出相应的测试方法,设计试验测试验证平台.最后,对模型中的影响因子进行仿真分析,分析结果表明：目标表面偏振二向反射特性与表面纹理特征、复折射率、入射光角度、探测方位角、天顶角等因素相关,且复折射率对目标表面反射率及反射光的偏振度影响较大,粗糙度会影响遮蔽与阻挡效应,使其产生突变效应.