广东湛江湖光岩地区玄武岩风化壳Fe同位素研究

本文对广东湛江湖光岩地区厚度分别为4 m和7 m的两个不同喷发时代玄武岩形成的风化壳样品进行Fe同位素分析,分析结果显示:厚度4m风化壳样品Fe同位素组成δ57Fe范围为0.17‰～0.57‰;厚度7 m风化壳样品Fe同位素组成δ57Fe范围为0.20‰～0.68‰,相对于标准物质IRMM-014,不同深度风化壳样品均显示Fe的重同位素富集.两风化壳剖面自下而上,随风化程度增大,风化壳样品中Fe同位素分馏程度也呈现逐渐增大的趋势,表明风化壳样品中Fe的重同位素富集趋势与风化壳的发育程度正相关,风化壳土壤中Fe同位素组成是反映土壤风化程度的指标.另一方面,风化过程可将地球外部圈层(岩石圈、水圈、生物圈)有机结合起来,风化壳土壤Fe同位素组成变化是表生植物和水淋滤共同作用的结果,对化学风化过程中Fe同位素研究,将会极大地补充表生过程中同位素地球化学的知识,同时Fe同位素可作为表生过程中物质的循环、环境的变化等过程中有力的示踪/指示技术手段加以应用.     

坚持正确方向严格规范管理——国土资源部有关部门负责人就国务院《关于严格规范城乡建设用地增减挂钩试点切实做好农村土地整治工作的通知》答记者问

日前,国务院公布《关于严格规范城乡建设用地增减挂钩试点切实做好农村土地整治工作的通知》,对严格规范城乡建设用地增减挂钩试点切实做好农村土地整治工作提出一系列要求。     

西部大地形变数据库设计与建设

介绍西部大地形变数据库的设计与建设.     

“走出去”稳扎稳打

老挝在2009年修订了《投资法》,不断改善本国的投资环境,为国内外投资者创造一个更公平的环境,并在成立外资企业审批方面简化了手续。投资者在较落后的地区投资,《投资法》还有充分的税收激励政策。     

Review of China's scientific research progress in polar meteorology in the last 30 years

The Antarctic and Arctic are sensitive to global climate change; therefore, they are key regions of global climate change research. This paper, the progress in scientific investigations and research regarding the atmosphere in the polar regions over the last 30 years by Chinese scientists is summarized. Primary understanding of the relationship between the polar regions and global change, especially, the variations in time and space in the Antarctic and Arctic regions with respect to climate change is indicated. Operational weather forecasts for investigation of the polar regions have also been established. Moreover, changes in sea ice and their impact on the atmosphere of polar regions have been diagnosed and simulated. Parameterization of the atmospheric boundary layer of different underlying layers and changes in the atmospheric ozone in the polar region has also been experimented. Overall, there has been great progress in studies of the possible impact of changes in the atmospheric environment of polar regions on circulation in East Asia and the climate of China.     

试论我国现行征地制度的法律问题

建立和完善与我国社会主义市场经济体制相适应的土地征用制度是一个关系到如何构建和谐社会以及社会主义新农村的重要问题。党的十六届三中全会通过的《中共中央关于完善社会主义市场经济体制若干问题的决定》中提出,完善农村土地制度,要按照保障农民权益和控制征地规模的原则,     

Spatiotemporal patterns of road network and road development priority in three parallel rivers region in Yunnan, China: An evaluation based on modified kernel distance estimate

Road network is a critical component of public infrastructure,and the supporting system of social and economic development.Based on a modified kernel density estimate(KDE)algorithm,this study evaluated the road service capacity provided by a road network composed of multi-level roads(i.e.national,provincial,county and rural roads),by taking account of the differences of effect extent and intensity for roads of different levels.Summarized at town scale,the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service.This method was applied to the road network of the Three Parallel River Region,the northwestern Yunnan Province,China to evaluate the development of road network in this region.In results,the total road length of this region in 2005 was 3.70×104km,and the length ratio between national,provincial,county and rural roads was 1∶2∶8∶47.From 1989 to 2005,the regional road service capacity increased by 13.1%,of which the contributions from the national,provincial,county and rural roads were 11.1%,19.4%,22.6%,and 67.8%,respectively,revealing the effect of′All Village Accessible′policy of road development in the mountainous regions in the last decade.The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority(RDP).Based on the modified KDE model and the framework of RDP evaluation,this study provided a useful approach for developing an optimal plan of road development at regional scale.     

Spatial heterogeneity of soil mineral oxide components in depression between karst hills,Southwest China

In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.     

广西北部湾土壤地球化学基准值与背景值特征

文章统计了广西北部湾地区深层土壤地球化学基准值与表层土壤背景值,并且对表深层土壤元素含量特征进行对比研究。结果显示,大部分表层土壤元素对深层土壤有一定的继承性,少部分元素如Cd、N、P、Cl、S、有机碳等受表生迁移活动和人为活动因素影响又与深层土壤有所差异。     

基于RS和GIS的甬台地区城市建设用地扩展特征研究

以多时相Landsat MSS,TM 和ETM卫星影像为数据源,利用遥感和GIS手段,提取宁波、台州2市5个时相(1979,1990,1995,2000和2005年)城市建设用地信息,分析了城市建设用地扩展的时间特征、形态特征、空间特征并通过其与人口、GDP因素的相关分析研究其扩展的动力机制.结果表明:①1979年以来,甬台地区城市建设用地总体扩展速度表现为先升后降,而城市建设用地总体扩展强度则表现为不断提高的趋势.②甬台地区城市建设用地的空间结构存在明显的分形特征,城市建设用地空间结构分维逐渐增大,城市建设用地空间复杂性增加,城市建设用地趋向不稳定.③甬台地区城市扩展与社会经济发展具有明显的相关性.