月球物理天平动对环月轨道器运动的影响

月球物理天平动是月球赤道在空间真实的摆动，会导致月球引力场在空间坐标系中的变化，从而引起环月轨道器(以下称为月球卫星)的轨道变化，这与地球的岁差章动现象对地球卫星轨道的影响类似．采用类似对地球岁差章动的处理方法，讨论月球物理天平动对月球卫星轨道的影响，给出相应的引力位的变化及卫星轨道的摄动解，清楚地表明了月球卫星轨道的变化规律，并和数值解进行了比对，从定性和定量方面作一讨论．     

月球大地测量学的进展

介绍了月球大地测量(Selenodesy)的定义和方法。月球大地测量的一个特点是它的观测数据绝大部分都要依靠航天探测器或环月、绕月卫星来获取。月球大地测量的内容可以考虑3个方面：一是在月球上给出一个有确定定义的坐标参考系。并在其中布测一个控制网；二是确定这一月球参考系的大地测量几何和物理常数；三是求定月球的外部重力场。     

分布式目录失效的恢复算法研究

提出了两种针对分布式目录失效情况时的恢复算法.基于元数据遍历的恢复算法采用遍历所有元数据的方式来近似地恢复目录,该算法能较完整地恢复目录.基于目录缓存的恢复算法采用目录缓存作为恢复的线索来近似地恢复目录,该算法能快速地恢复目录.两种算法在目录恢复上各有优缺点,通过实验验证了两种算法的功能,并对其性能做了比较.     

GNSS接收机与全站仪控制点恢复测量及精度分析

主要利用GNSS接收机与全站仪对基坑控制点进行恢复测量,GNSS接收机通过RTK技术在基坑周边重新布设5个控制点,利用全站仪假定方向推算出控制点的坐标,并且分析其相对精度。通过实地观测计算分析,推算出的坐标与基坑中心点位置X方向相差5 mm、Y方向相差4 mm,恢复后的控制点能够对其他特征点进行详细测设。利用高精度的0.5″级全站仪进行点位测量精度对比分析,点位精度在2 mm范围之内,可以得出工程单位所用的仪器可满足精度,能够用于此类工程点位测设工作。     

Two Lunar Mare Soil Simulants

Two new lunar mare soil simulants, NAO-2 and NAO-3, have been created in National Astronomical Observatories (NAO), Chinese Academy of Sciences. These two simulants were produced from low-titanium basalt and high-titanium basalt respectively. The chemical composition, mineralogy, particle size distribution, density, angle of internal friction, and cohesion of both simulants have been analyzed, indicating that some characteristics of NAO-2 and NAO-3 are similar to those of Apollo 14 and Apollo 11 landing site soils. NAO-2 and NAO-3 will be of great benefit to the scientific and engineering research on lunar soil.     

Quantifying TiO_2 Abundance of Lunar Soils:Partial Least Squares and Stepwise Multiple Regression Analysis for Determining Causal Effect

Partial least squares(PLS) regression was applied to the Lunar Soil Characterization Consortium(LSCC) dataset for spectral estimation of TiO2.The LSCC dataset was split into a number of subsets including the low-Ti,high-Ti,total mare soils,total highland,Apollo 16,and Apollo 14 soils to investigate the effects of interfering minerals and nonlinearity on the PLS performance.The PLS weight loading vectors were analyzed through stepwise multiple regression analysis(SMRA) to identify mineral species driving and...     

煤矿复采量与动用量和“三率”关系研究

通过分析煤炭资源复采量、复损量与当期（年）动用量、历年累计动用量、当期（年）采出量、当期（年）损失量之间的关系,提出了复采量计算公式,并阐述了复采量与生产矿井＂三率＂之间的关系。分析认为复采量参与当期（年）＂三率＂计算,能够确保当期（年）＂三率＂统计的真实性、准确性、合理性,从而提升煤炭资源储量管理水平和质量,同时建议修订生产矿井储量管理规程、矿井地质规范。     

Relating snow dynamics and balsam fir stand characteristics,Montmorency Forest,Quebec

Snow water equivalent was measured during three springs on north‐ and south‐exposed sites representing a range of stand structure and development stages of Quebec's balsam fir forest. Maximum snow water equivalent of the season, mean seasonal snowmelt rate, snowmelt season duration and total snowmelt season degree‐day factor were related to canopy height, canopy density, light interception fraction and basal area of the stands using random coefficient models. Seasonal mean snowmelt rate was better explained by stand characteristics (R² from 0·41 to 0·61) than was maximum snow water equivalent (R² from 0·08 to 0·23). The best relationship was found with light interception, which explained 61% of snowmelt rate variability between stands. These relationships were not significantly affected by stand aspect (Pr ≥ S = 0·14 or higher), as snow dynamics seemed less dependent on aspect than on stand characteristics. Snowmelt recovery rates could be used by forest planners to establish an acceptable time step for the harvesting of different parts of a watershed in order to prevent peak flow augmentations. Copyright © 2005 John Wiley & Sons, Ltd.     

月球卫星轨道力学综述

月球探测器的运动通常可分为3个阶段，这3个阶段分别对应3种不同类型的轨道：近地停泊轨道、向月飞行的过渡轨道与环月飞行的月球卫星轨道。近地停泊轨道实为一种地球卫星轨道；过渡轨道则涉及不同的过渡方式(大推力或小推力等)；环月飞行的月球卫星轨道则与地球卫星轨道有很多不同之处，它决不是地球卫星轨道的简单克隆。针对这一点，全面阐述月球卫星的轨道力学问题，特别是环月飞行中的一些热点问题，如轨道摄动解的构造、近月点高度的下降及其涉及的卫星轨道寿命、各种特殊卫星(如太阳同步卫星和冻结轨道卫星等)的轨道特征、月球卫星定轨等。