基于LAMOST对银河系晕星轨道偏心率的研究

基于LAMOST的A/F/G/K型巨星样本，通过空间分布和金属丰度分布挑选晕星样本并进一步研究银河系晕星的轨道偏心率。研究发现：在距离银盘5~15 kpc的范围内，晕星的偏心率峰值均在0.8左右，并不随距离的增大而改变，但垂直距离越大时峰值处晕星所占比也越大。在5 <|z|<25 kpc的范围内，内晕星和外晕星在偏心率的分布上有明显的差异：内晕星偏心率的峰值在0.65左右，分布较为弥散；而外晕星偏心率的峰值在0.8左右，大部分集中在e>0.6的区域。这些不同的运动学特征反映了内外晕的形成机制不同。     

Torsional effect of space structure in frequent earthquakes

Taking a concrete frame supporting space structure as the research object, we systematically studied its lateral-torsion coupling effect of reverse problems in consistent earthquake excitation. Firstly, based on its reverse forms and features, we put forward a mechanical analysis model (flexibility layer model) and a calculation method using the response spectrum method and the weighted average method, and verified their validity and feasibility using case analysis. The result shows that the translation displacement change trend of the space structure is basically the same whether reverse exists in the supporting structure or not, but the supporting structure torsion has an effect on the displacement with a relative increase of 10?.     

基于LAMOST对银河系厚盘恒星轨道偏心率及厚盘形成机制的研究

基于LAMOST光谱数据,选取一个太阳邻域F/G型主序星样本研究银河系厚盘恒星的轨道偏心率分布.厚盘星是基于空间位置和金属丰度[Fe/H]来证认,同时分析薄盘星的污染带来的影响.发现厚盘恒星轨道偏心率分布在低偏心率（约为0.2）处有一个峰值,而且向高偏心率延伸一个尾巴（到e~0.8）.把得到的厚盘恒星偏心率分布与4个厚盘形成模型进行对比,发现此结果与富气体并合模型最为符合.     

数字化测图中偏心测量用法的改进探讨

在数字化采集过程中,当遇到棱镜难于直接安置在目标点时,采用偏心测量方法能够获得较好的测量效果。本文对偏心测量方法进行了一些改进,对实际测量有指导意义。     

The relationship between the golf swing plane and ball impact characteristics using trajectory ellipse fitting

The trajectory of the clubhead close to ball impact during the golf swing has previously been shown to be planar. However, the relationship between the plane orientation and the orientation characteristics of the clubhead at ball impact has yet to be defined. Fifty-two male golfers (27 high skilled, 25 intermediate skilled) hit 40 drives each in an indoor biomechanics laboratory. This study successfully fitted the trajectory of the clubhead near impact to an ellipse for each swing for players of different skill levels to help better explain this relationship. Additionally, the eccentricities of the ellipses were investigated for links to skill level. The trajectory of the clubhead was found to fit to an ellipse with RMSE of 1.2 mm. The eccentricity of the ellipse was found to be greater in the high-skilled golfers. The club path and angle of attack generated from the ellipse fitted clubhead trajectory were found to have a normalised bias-corrected RMSE of 2% and 3%, respectively. A set of “rule of thumb” values for the relationship between the club path, angle of attack and delivery plane angle was generated for use by coaches.     

曲线道路中线的偏心测设法

本文介绍一种以偏心测设曲线道路的方法, 该法能使曲线道路的测设具有灵活性, 适用于通视条件极差以及新建道路工程的复杂地形等。     

THEORETICAL INVESTIGATION ON THE TECHNIQUES OF ERROR SEPARATION USING THREE PROBES

In this paper,the following problems are discussed:the mounting conditionsof three probes,the transmission characteristics of measuring system,the elimination ofmounting eccentricity,and so forth.The measures for solving these problems are also pres-ented.At last,the author gives some ideas about the solubility and the correlations of theoutput equations.     

圆锥曲线离心率与参变量的关系

利用参变量的变化范围及圆锥曲线的性质，求圆锥曲线的离心率。     

按许用压力角确定推杆凸轮机构基本尺寸的完全解析法

基于解析几何法导出的最大压力角表达式,导出了偏心凸轮机构和对心凸轮机构的基圆半径和偏距的计算公式。只要从动件为常用的运动规律以及不超过3次的多项式运动规律,在满足许用压力角的前提下,采用该解析法确定凸轮基圆半径和偏距,比其它解析法简捷方便。     

解析法确定从动件为等速运动规律的凸轮基圆半径

本文尝试采用解析法，按许用压力角确定直动从动件盘形凸轮机构的基圆半径和偏心距。该方法只适用于从动件为等速运动规律的凸轮机构。