Minor planet short periodic perturbations: The indirect part of the disturbing function

Leverrier's development of the indirect part of the disturbing function has been extended to include terms up to degree 4 in eccentricity and inclination; the resulting series has been expressed with respect to a fixed plane, and in a computer readable form (a list of integers). Tests have been performed for the relative significance of the terms of degrees 2, 3 and 4, and estimates have been obtained for the accuracy of the short periodic perturbations of a minor planet, and of the corresponding mean orbital elements. It was found that: (i) even in extreme cases, the indirect part of the disturbing function gives rise to very small short periodic perturbations; (ii) bodies of very high eccentricity/inclination and those close to mean motion resonances are most significantly affected; (iii) indirect perturbations for minor planets can be computed up to the degree 2 terms only, without any significant loss of accuracy; and (iv) higher degree indirect perturbations appear to be important only for their contribution to the long periodic effects of higher order (with respect to the perturbing mass).     

应用分块矩阵求逆解算约束秩亏间接平差模型

在通常的四分块矩阵求广义逆矩阵和凯利逆矩阵公式基础上,分析左上角子矩阵为秩亏、右下角子矩阵为零的特殊四分块矩阵的凯利逆矩阵存在条件,应用广义逆矩阵法和矩阵变换法推导该类特殊四分块矩阵的凯利逆矩阵显性表达公式,并用于解算约束秩亏间接平差模型的参数估计.实验数据表明,当满足存在性条件时,应用分块矩阵求逆公式解算约束秩亏间接...     

数字化地形图对象的几何约束和平差

主要对数字化地形图对象进行几何约束平差.以房屋为例进行了直角纠正,并通过VB的程序设计来实现.     

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Indirect radiative forcing and climatic effect of the anthropogenic nitrate aerosol on regional climate of China

The regional climate model (RegCM3) and a tropospheric atmosphere chemistry model (TACM) were coupled, thus a regional climate chemistry modeling system (RegCCMS) was constructed, which was applied to investigate the spatial distribution of anthropogenic nitrate aerosols, indirect radiative forcing, as well as its climatic effect over China. TACM includes the thermodynamic equilibrium model ISORROPIA and a condensed gas-phase chemistry model. Investigations show that the concentration of nitrate aerosols is relatively high over North and East China with a maximum of 29 μg m^-3 in January and 8 μg m^-3 in July. Due to the influence of air temperature on thermodynamic equilibrium, wet scavenging of precipitation and the monsoon climate, there are obvious seasonal differences in nitrate concentrations. The average indirect radiative forcing at the tropopause due to nitrate aerosols is -1.63 W m^-2 in January and -2.65 W m^-2 in July, respectively. In some areas, indirect radiative forcing reaches $-$10 W m^-2. Sensitivity tests show that nitrate aerosols make the surface air temperature drop and the precipitation reduce on the national level. The mean changes in surface air temperature and precipitation are -0.13 K and -0.01 mm d^-1 in January and -0.09 K and -0.11 mm d^-1 in July, respectively, showing significant differences in different regions.     

南京站降水量的统计分析

通过对南京站降水量的统计分析，验证了南京站降水量雨型为P-Ⅲ型分布。随着城市化的进程。人类活动加剧，南京站的降水量和发生大雨、暴雨的年均次数均有增加的趋势，1970年后趋势更加明显。城市降水量的增大及大雨和暴雨次数的增多，出现峰高量大的暴雨洪水机会增加，加剧了南京的防洪压力。     

中国旅游产业发展间接就业带动能力测算及其时空差异

旅游产业快速发展不仅直接就业效应大,而且对其他行业的间接就业带动能力更为显著。本文结合旅游剥离系数和投入产出分析方法,构建旅游产业发展的间接就业带动能力测算模型,利用Dagum基尼系数分解其时空差异演变,基于中国31个省（自治区、直辖市）的面板数据对旅游产业发展间接就业带动能力及其时空差异进行实证测算。结果显示：中国旅游产业间接就业带动规模从2000年的2684.6万人增长到2019年的4894.9万人,旅游产业发展间接就业带动能力显著提高;各省份旅游产业发展间接就业带动能力存在明显差距,总体上表现为东、中、西部地区依次递减;纵向比较来看,旅游间接就业带动作用有效突破了胡焕庸线的约束,但带动作用较强的地区主要集中在胡焕庸线东南半壁;对不同产业的间接就业带动能力差异显著,其中,对农林牧渔业和制造业的间接就业带动能力最突出;旅游行业内部比较来看,旅游交通运输、仓储和邮政通讯业、旅游住宿和餐饮业的间接就业带动能力处于主导地位;旅游间接就业带动能力总体差异呈收敛趋势,这种总体差异主要来源于地区间差距。     

借助最小二乘配置整体解算地壳视应变场

研究利用多手段（ＧＰＳ、跨断层等）形变资料,结合定点应变数据解算地壳视应变场的方法,包括利用间接平差法求单元内部的均匀视应变及借助最小二乘配置求水平视应变连续分布。对华北地区ＧＰＳ监测网１９９２年、１９９５年和１９９６年３期成果进行计算分析,得到其视应变场动态图像。     

物流业发展对产业结构优化的实证分析 ——基于空间面板杜宾模型

目前,我国正处于产业结构优化升级和实现经济发展方式转变的关键时期。物流业作为第三产业的重要组成部分,具有有效降低经济运行成本、提高运作效率和促进产业结构升级的作用。文章首先对省域产业结构合理化和产业结构高级化空间依赖性进行了检验。然后,基于我国1997―2010年30个省级面板数据,通过引入因变量空间滞后项和自变量空间滞后项,构建空间面板杜宾模型,从产业结构合理化和产业结构高级化2个方面分析物流业发展对产业结构优化的影响。研究结果表明：我国产业结构合理化和产业结构高级化存在着显著为正的空间溢出效应,东部、中部和西部地区存在着明显的空间差异;物流业的发展不仅能够显著促进当地产业结构合理化和产业结构高级化进程,而且对邻近地区产业结构优化具有正向的空间溢出效应。最后,文章有针对性地提出了政策建议。