Triassic alkaline intrusives in the Yanliao-Yinshan area: their chronology, Sr, Nd and Pb isotopic characteristics and their implication

Dated isotopic ages for 15 alkaline intrusives in the Yanliao-Yinshan area, ranging from 268 to 190 Ma, ten of which are from 250 to 208 Ma, indicate that most of them were formed in the Triassic Epoch. All the E_Nd(t) ratios from - 17.19 to -3.21 averaging -7.09, the E_Sr(t) ratios fmm 11.7 to71.5 averaging 36.63, and the I_sr(t) ratios from 0.705 0 to 0.709 3 averaging 0.706 8, show their characteristics of enrichment. On the E_Nd (t) virus E_Sr(t) correlation diagram, the samples from these intmsives were plotted within the enriched mantle trend lines and just outside, demonstrating their close connection to materials from the enriched mantle reservoir, taking into account the same Pb isotopic composition as that of the mantle.     

东北振兴以来吉林省区域经济差异的时空演变研究

基于吉林省2003~2015年间地区生产总值和人均地区生产总值数据,以市域、县域两个尺度单元为研究对象,采用人口加权变异系数、基尼系数、泰尔指数等统计分析方法,对吉林省东北振兴战略实施以来的13 a内,区域经济差异的时空演变进行定量分析,并运用泰尔指数的分解方法,探讨了吉林省区域经济差异的空间格局。结果发现：① 吉林省区域经济总体差异、市域差异、县域差异均呈逐年下降趋势。② 通过差异贡献率显示：县域差异是区域总体差异变化的主导力量,长春市域的内部差异远高于其他市域,但有逐年减小的趋势,长吉两地的二元结构仍然突出,是全省区域经济差异产生的主要来源,主导着全省区域经济差异走向;③ 从2003~2015年来看,全省经济增长速度较快的地区主要还是集中在“三核一带”;④吉林省经济差异主要是由资源禀赋、产业结构、极化效应和政策导向等多种因素综合作用的结果。     

Modeling spatial and temporal change of soil erosion based on multi-temporal remotely sensed data

In order to monitor the pattern, distribution, and trend of land use/cover change (LUCC) and its impacts on soil erosion, it is highly appropriate to adopt Remote Sensing (RS) data and Geographic Information System (GIS) to analyze, assess, simulate, and predict the spatial and temporal evolution dynamics. In this paper, multi-temporal Landsat TM/ETM+ remotely sensed data are used to generate land cover maps by image classification, and the Cellular Automata Markov (CA_Markov) model is employed to simulate the evolution and trend of landscape pattern change. Furthermore, the Revised Universal Soil Loss Equation (RUSLE) is used to evaluate the situation of soil erosion in the case study mining area. The trend of soil erosion is analyzed according to total/average amount of soil erosion, and the rainfall (R), cover management (C), and support practice (P) factors in RUSLE relevant to soil erosion are determined. The change trends of soil erosion and the relationship between land cover types and soil erosion amount are analyzed. The results demonstrate that the CA_Markov model is suitable to simulate and predict LUCC trends with good efficiency and accuracy, and RUSLE can calculate the total soil erosion effectively. In the study area, there was minimal erosion grade and this is expected to continue to decline in the next few years, according to our prediction results.     

基于PPT战略的广东省乐昌市生态旅游扶贫模式探讨

以贫困人口受益为出发点,基于有利于贫困人口发展的旅游(Pro-Poor Tourism,PPT)战略,以广东省乐昌市为例,开展适用于中国南方林区生态旅游扶贫开发的发展模式和旅游扶贫产业的发展路径研究.结果表明:1)政府部门、旅游企业、乡村社区和非营利社会组织都应在提升贫困人口参与度、减轻贫困和生态保护方面承担责任,具体...     

Changes in wheat potential productivity and drought severity in Southwest China

Theoretical and Applied Climatology - Wheat production in Southwest China (SWC) plays a vital role in guaranteeing local grain security, but it is threatened by increasingly frequent seasonal...     

土地规划的自然过程基础与大数据时代的方法探索

随着城市化与工业化程度不断加深,产业空间结构不断重组,导致土地供需矛盾日益突出,国土资源无序开发日益严重,因而优化国土资源空间格局,成为生态文明建设的首要任务。同时,科学合理配置土地资源对土地规划提出了更高要求,传统土地规划方法有待改革。在基于尊重自然、顺应自然的开发理念下,总结土地自然过程基础对土地规划的影响,实现“山水路林田生命共同体”的协调规划发展。其次,“大数据”时代的来临,云计算、空间数据整合、云分析等技术对土地规划方法提供新的技术支撑;最后,针对土地规划数据特殊性、移动用户终端的广泛性,提出应创建土地规划云服务平台,使土地规划实现数据集成管理和更新,从而提高土地规划质量。     

Extended FRAG-BASE schema-matching method for multi-version open GIS Web services retrieval

The OGC Web Service (OWS) schemas have the characteristics of a complex element structure, are distributed and large scale, have differences in element naming, and are available in different versions. Applying conventional matching approaches may lead to not only poor quality, but also bad performance. In this article, the OWS schema file decomposition, fragment presentation, fragment identification, fragment element match, and combination of match results are developed based on the extended FRAG-BASE (fragment-based) schema-matching method. Different versions of Web Feature Service (WFS) and Web Coverage Service (WCS) schema-matching experiments show that the average recall of the extended FRAG-BASE matching for the schemas is above 80%, the average precision reaches 90%, the average overall achieves 85%, and the matching efficiency increases by 50% as compared with that of the COMA and CONTEXT matcher. The multi-version WFS retrieval under the Antarctic Spatial Data Infrastructure (AntSDI) data service environment demonstrates the feasibility and superiority of the extended FRAG-BASE method.     

地方嵌入对在华外资企业出口市场多元化的影响

外资企业通过直接出口和间接溢出效应对中国出口增长做出了巨大贡献.现有文献大多基于外资企业知识溢出研究其对本地出口和创新等方面的促进作用,较少关注外资企业自身的贸易活动.利用2000-2016年中国海关贸易数据库,在全球-地方互动视角下,搭建本地、目的国(地区)和本地-目的国(地区)联系三维度框架,重点关注外资企业地方嵌...     

中国环境经济地理的研究主题展望

全球环境变化与技术经济范式变革对“经济-环境”关系产生深刻影响,但资源环境议题自20世纪80年代以来逐渐淡出全球经济地理研究的视野。2000年以来,环境经济地理逐渐兴起并对此进行反思,但其发展仍处于混沌状态。中国经济地理学科自身的人地关系传统和国家发展的探索与实践,为环境经济地理理论与实践创造了理想条件。环境经济地理并非全新的领域,其可从经济地理理论出发拓展对“经济-环境”关系的认识,据此提出3组研究主题：① 重新认识经济活动的区位,理解变化中的资源环境如何作用于传统与新兴经济活动;② 建立对不同地理尺度下要素流动和主体互动的认知,理解资源环境风险如何在各类关系网络中传递,又将如何重塑各类关系网络;③ 考察多主体在多区域之间、多层级制度背景下的相互作用,理解绿色创新与转型的过程,实现对“经济-环境”关系在不同发展场景下协同演化的认识。