基于TLE时序的GEO目标东西机动预报

赤道带GEO非合作目标的频繁机动监测是空间态势感知的重要工作.文中给出了GEO卫星东西漂移律和周期性位置保持机动原理,指出相关轨道特征参数有规律性跃变;利用公开下载的双行轨道根数TLE(Two-line Element),提出基于平经度及其漂移率的GEO东西机动周期提取和预报方法.为了提高数据源质量,利用SDP4模型将...     

数字技术力量下的乡村重构

随着数字技术逐渐深入到乡村生产生活的各个方面,乡村社会关系及空间意义发生重构。信息化冲击下的乡村空间转变不仅体现在物质方面,其社会文化空间意义及人地关系地域系统的重构在内生逻辑上重塑乡村话语权力和主体身份。论文通过探讨数字技术与乡村发展的多维关系及其对乡村产生的多重效应,关注数字技术带来的自由与异化、数字经济引发的话语与权力流变及乡村女性主体地位和身份的重构,解释了数字技术作为非人类行动者的主体性及其建构下的乡村日常经济生活和社会关系,拟为乡村性的分析框架提供有益的补充,为数字乡村建设和乡村振兴提供新的理论借鉴。     

Detrital zircon geochronology and provenance of sediments within the Mesozoic basins:New insights into tectonic evolution of the Qinling Orogen

Mesozoic sedimentary units within the Nanzhao and Mashiping basins record the paleogeographic and tectonic evolution of the Qinling Orogen (QO). This study uses...     

Dynamical features of near-inertial motions in global ocean based on the GDP dataset from 2000 to 2019

Based on the latest oceanic surface drifter dataset from the global drifter program during 2000–2019, this study investigated the global variation of relative frequency shift(RFS), near-inertial energy(NIE) and inverse excess bandwidth(IEB) of near-inertial motions, and analyzed their relations with oceanic mesoscale dynamics, relative vorticity and strain. Compared with previous works, we have some new findings in this study:(1) the RFS was high with negative values in some regions in which we found a significant blue shift of the RFS in the equatorward of 30°N(S) and from 50°N to 60°N in the Pacific, and a red shift in the western boundary currents and their extension regions, the North Atlantic and the Antarctic Circumpolar Current regions;(2) more peak values of the NIE were found in global regions like the South Indian Ocean, the Luzon Strait and some areas of the South Ocean;(3) the global distribution of the IEB were characterized by clear zonal bands and affected by vorticity and wind field;(4)the RFS was elevated as the absolute value of the gradient of vorticity increased, the IEB did not depend on the gradient of vorticity, and the eddy kinetic energy(EKE) weakened with the decrease of the absolute value of RFS;(5) the NIE decreased with increasing absolute value of the relative vorticity and the gradient of vorticity, but it increased with increasing strain and EKE when EKE was larger than 0.003 2 m~2/s~2.     

基于模糊物元模型的中国旅游生态安全评价及障碍因子诊断研究

基于DPSIR模型构建旅游生态安全评价指标体系,利用模糊物元模型对中国31个省(市、区)(不含港澳台)旅游生态安全进行动态评价,并运用空间自相关分析空间格局演化特征.同时借助障碍度模型,对旅游生态安全的障碍因子进行诊断.结果表明:①旅游生态安全呈现出波动增长的"W"型演化趋势.2013-2016年中国旅游生态安全在空间...     

全民所有自然资源资产管理考核评价机制与方法研究

本文采用对比分析与归纳分析法,在明确全民所有自然资源资产管理考核评价机制定位的基础上,充分借鉴和参考现有相关考核评价制度的设计思路,围绕“考核谁、谁来考、怎么考、考什么、结果怎么定、结果怎么用”等关键问题,从考核评价对象和实施主体、考核评价方式和实施、考核评价结果应用、考核评价内容和指标体系构建、考核评价结果评定方法等方面,提出构建全民所有自然资源资产管理考核评价机制和方法的思路,为推进生态文明建设和自然资源资产产权制度改革提供支撑。     

改进的能量守恒方法及其在CHAMP重力场恢复中的应用

An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year＇s worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S.     

基于交互多模型的水下目标跟踪方法

According to the requirements of real-time performance and reliability in underwater maneuvering target tracking as well as clarifying motion features of the underwater target, an interacting multiple model algorithm based on fuzzy logic inference （FIMM） is proposed. Maneuvering patterns of the target are represented by model sets, including the constant velocity model （CA）, the Singer mode~, and the nearly constant speed horizontal-turn model （HT） in FIMM technology. The simulation results show that compared to conventional IMM, the reliability and real-time performance of underwater target tracking can be improved by FIMM algorithm.     

Preface

The Climate System Model Development and Application Studies （CSMDA for short） is an International Partnership Program for Creative Research Teams that was started in October 2004 and is supported by the Chinese Academy of Sciences （CAS）. The initial objectives are ＂to develop a sustainable climate system model that can represent the interaction of different spheres in the climate system, to provide a cross-cut research platform for atmospheric sciences, oceanography and other related fields, and to offer theoretical support for developing and improving reasonable short-range climate prediction systems＂.