测绘相机内方位元素在对地定位中的误差传播

文章从三线阵测绘相机的摄影测量原理出发,推导了内方位元素在对地立体定位中的误差传播规律。经过模拟计算表明,理论估计结果与实际相符,相关公式可用于测绘相机的几何指标分析。     

从雷达测速数据辨识弹丸符合阻力系数曲线的最优控制解法研究

把从雷达测速数据提取弹丸符合阻力系数曲线问题看成一个以符合阻力系数曲线为控制函数的奇异最优跟踪控制问题,给出了直接数值求解的具体算法;还应用了亏数为2的三次样条多项式表述符合阻力系数曲线的解法,使泛函极小问题转化为多变量参数极小问题,有效地克服了该奇异最优控制问题直接数值解法上的困难。处理了真实打靶数据,其结果表明,本文方法及软件有一定的实际应用价值。     

非线性规划的内割平面法

本文提出了一种非线性凸规划的内割平面法(ICPM),同时说明了与Kelley外割平面法交互使用的方法。并就ICPM算法给出了一个示例。     

脱壳穿甲弹气动力-外弹道优化设计

本文将脱壳穿甲弹结构参数在飞行弹道上对空气动力特性、外弹道特性的相互影响作了分析,提出了在飞行弹道上对主要结构参数进行气动力-外弹道一体化优化设计的必要性。基于脱壳穿甲弹的弹道特点和战术技术要求,确定了优化设计变量、目标函数、约束函数。建立了一体化的优化设计数学模型,并利用空气动力数值计算、外弹道数值计算和最优化方法进行求解,编制了一套设计软件。通过对某小口径火炮脱壳穿甲弹优化设计应用表明,软件计算精度较高,优化设计后的脱壳穿甲弹主要弹道性能有了大幅度抛高,优化设计收到了很好的效果。     

某装药用双基推进剂的配方选择及实验

为克服某起动器用复合推进剂装药存在燃气残渣多的缺陷，通过物性数据比较及内弹道性能计算，从三个备选双基配方中选出一个与该复合装药性能相近的配方来替代它。对选出的双基配方进行了验证，同时研究了辅助催化剂、辅助增塑剂、燃烧稳定剂对双基推进剂燃烧性能的影响。实验表明：所选的双基推进剂能满足该起动器对装药的要求。     

串装双燃速药柱发动机的内流场计算

对一维的加质燃烧室流场、轴对称的二维喷管内流场和高燃速药柱燃烧完成后的燃烧室二维内流场以及三维药柱几何做了一体化计算。应用轴对称的N－S方程、TVD有限体积法的显式MacCormack格式，对燃烧室后段和长尾喷管跨声速流场进行求解，得到了双燃速内弹道性能和轴对称二维流场中燃气参数的分布。结果具有较高的精度，并为进一步的燃烧室和喷管热结构分析提供数值依据。     

固体火箭发动机一维准定常内弹道解法

本文着重讨论了固体火箭发动机一维准定常内弹道问题的解法.指出这个问题可有两种解法:平衡解法和非平衡解法,并用实例计算说明了非平衡解法优于平衡解法.     

Mercury’s Interior Structure, Rotation, and Tides

This review addresses the deep interior structure of Mercury. Mercury is thought to consist of similar chemical reservoirs (core, mantle, crust) as the other terrestrial planets, but with a relatively much larger core. Constraints on Mercury’s composition and internal structure are reviewed, and possible interior models are described. Large advances in our knowledge of Mercury’s interior are not only expected from imaging of characteristic surface features but particularly from geodetic observations of the gravity field, the rotation, and the tides of Mercury. The low-degree gravity field of Mercury gives information on the differences of the principal moments of inertia, which are a measure of the mass concentration toward the center of the planet. Mercury’s unique rotation presents several clues to the deep interior. From observations of the mean obliquity of Mercury and the low-degree gravity data, the moments of inertia can be obtained, and deviations from the mean rotation speed (librations) offer an exciting possibility to determine the moment of inertia of the mantle. Due to its proximity to the Sun, Mercury has the largest tides of the Solar System planets. Since tides are sensitive to the existence and location of liquid layers, tidal observations are ideally suited to study the physical state and size of the core of Mercury.     

飞行状态下固体火箭发动机比冲计算

以固体导弹飞行试验的外弹道测量数据和遥测数据为基础，将外弹道计算模型与固体发动机内弹道计算型相结合，建立了飞行状态下固体发动机比冲的计算模型，算例表明，该模型适用于固体发动机性能的快速工程分析。     

Mixing in Stars and the Evolution of the 3He Abundance

We first recall the observational and theoretical facts that constitute the so-called 3He problem. We then review the chemical anomalies that could be related to the destruction of 3He in red giants stars. We show how a simple consistent mechanism can lead to the destruction of 3He in low mass stars and simultaneously account for the low 12C/13C ratios and low lithium abundances observed in giant stars of different populations. This process should both naturally account for the recent measurements of 3He/H in galactic HII regions and allow for high values of 3He observed in some planetary nebulae. We propose a simple statistical estimation of the fraction of stars that may be affected by this process.