中国城市群空间结构的稳定性分析

应用中心地理论,引入中心性指数和分形网络维数等方法以及GIS格网化技术,按照交通原则,即K ＝4作为参照系,采用2004年基础数据,对由160个地级市和700多个县级市构成的28个城市群及其空间结构的稳定性进行了定量测度。结果显示：① 中心性指数越大的城市群,其空间结构稳定性越强;② 中心性指数越大,与中心地结构相似性程度越高,空间稳定性越强;③ 网络维数越大,城市群空间结构稳定性越强;④ 点列数越长的城市群空间结构稳定性越强;⑤ 依据中心性指数大小,可将中国城市群划分为单核分割型、单核偏离型、单核集中型、双核平衡型和双核偏离型共5大类型;⑥ 根据半升梯形模糊隶属度函数模拟结果,将中国城市群空间结构稳定性划分为强稳定型、较强稳定型、中等稳定型、弱稳定型和不稳定型共5个等级;⑦ 根据不同等级的城市群个数,认为中国城市群空间结构的稳定性相对较差。本文最后提出了技术应用、参数选择等方面存在的问题以及未来研究的重点。     

一种嵌入式空间数据引擎的设计与实现

空间数据引擎是实现高效空间数据访问和管理的关键技术之一。本文提出一种基于内存映射文件和改进堆组织表方式的嵌入式空间数据引擎设计与实现方法,分析了该数据引擎的组成部分和关键算法,并在其基础上讨论了日志及事务的实现方法。通过对实际数据的实验对比,其结果表明:基于本文方法开发的系统和目前主流嵌入式数据库相比,具有数据访问速度快,占用内存少的特点,适合于空间数据的编辑环境。     

Basin-scale structure control of Carlin-style gold deposits in central Southwestern Guizhou,China: Insights from seismic reflection profiles and gravity data

Carlin-style gold deposits are widely distributed in Southwestern Guizhou, China. Research has dominantly focused on deposit-scale geology and structural control of mineralization. The relationship between the gold deposits and regional structures, in particular their control on the formation and distribution of those deposits is less well understood. Here we use seismic survey and gravity data to reveal the basin-scale structure control of the gold deposits in central Southwestern Guizhou. The seismic reflection profiles show strong reflection horizons including Upper Permian coal measures, and Dongwu and Guangxi unconformities. The seismic data provide important evidence of the basinal structural style and the relationship between fault-related folding and the Carlin-style gold deposits. Regional gravity data also revealed several paleo-uplifts, which appear to control the distribution of Carlin-style gold deposits.The Carlin-style gold deposits are spatially and temporally associated with fault-related folds. Based on their location, we classify the gold deposits into two types, (1) low-angle thrust-controlled deposits; and (2) high-angle reverse fault-related deposits. In the low-angle thrust-controlled deposits, main thrusts are listric, strike NW-SE and dip southwest. These thrusts detach into coal measures, tuffs and volcanic rocks and are bedding-parallel in the vicinity of the Dongwu unconformity. Gold ore bodies are found in the thrusts and characterized by cutting-layer veins near the surface and bedding-parallel veins at depth. The high-angle reverse fault-related deposits are located in the hinge of northeast-southwest-striking fault-related folds, with high-angle reverse faults near the hinge of folds crosscutting the Upper Permian coal measures, volcanic rocks and Dongwu unconformity, and then into the limestone of Middle Permian Maokou Formation. Ore bodies are bedding-parallel in anticline culminations where interlayer fracture zones in Upper Permian coal measures and volcanic rocks are generated by high-angle reverse faulting.We consider that the formation of the gold deposits is part of the tectonic evolution in the area. The two sets of NW-SE- and NE-SW-striking fault-related folds were successively formed during the closure of eastern Tethys Ocean in Late Triassic, and major gold deposits formed in the fault-related folds. The Dongwu unconformity and faults provided conduits for ore fluid flow, and the coal measures and the tuffs of Dachang Member acted as detachment layers and hosts for ore deposition.     

Spatial analyses of factors affecting household structure in Chinese cities: The case of three-generation lineal households

Household structure is an important aspect of family change during China’s modernization process. Existing literature has demonstrated significant associations between various factors and household structure, but the spatial variation in these relationships has not been examined. Using the 2010 Chinese population census data and geographically weighted regression (GWR) model, this study explored the spatial patterns of three-generation lineal households, a functionally important household type in China, and its influencing factors. There was significant heterogeneity in the distribution of three-generation lineal households. Socioeconomic, demographic, and cultural factors were all significantly related to the proportion of three-generation lineal households, but the relationships are place-specific in terms of direction and magnitude. These results suggest that the distribution of Chinese household structures cannot be explained by a single framework of family modernization theory but is determined by the interplay of various local characteristics. Especially, population migration plays an equally important role in affecting household structure than socioeconomic development in China. This work contributes to the family literature by highlighting the spatial heterogeneity in the impact of varying factors on household structure. Beyond the classic modernization theory, it sets a contextualized framework for understanding how Chinese household change in response to the rapid social transformation.     

桂东南宁潭岩体地质特征及其构造环境初探

宁潭岩体是由马田、亭子、陈冲、老虎头 4个单元组成的遭受了变形变质改造的花岗岩复式岩体。岩石学、岩石化学、地球化学特征反映该岩体属后碰撞强过铝花岗岩。其源区既包含有不成熟的富含长英质物质的特性 ,也有成熟的、富含粘土的特性。岩体的形成温度为 85 0～ 92 5℃ ,同位素年龄为 35 4～ 4 4 0Ma。可能是加里东期扬子板块与华夏板块碰撞后 ,在拉伸构造作用下岩浆底辟侵位而成     

Lithospheric structure and continental geodynamics

This paper briefly reviews main progress in the research on lithospheric structure and continental geodynamics made by Chinese geophysicists during last 4 years since 22nd IUGG general assembly in July 1999. The research mainly covers the following fields: investigations on regional lithospheric structure, DSS survey of crust and upper mantle velocity structure, study on present-day inner movement and deformation of Chinese mainland by analyz-ing GPS observations, geodynamics of Qingzang plateau, geophysical survey of the Dabie-Sulu ultra-high pressure metamorphic belt and probing into its formation mechanism, geophysical observations in sedimentary basins and study on their evolution process, and plate dynamics, etc.     

基于SSM的云南省产业结构水平测评

基于传统偏离-份额分析法（SSM）以及动态偏离-份额分析法,首先对中国西部地区12省（直辖市、自治区）产业结构进行横向对比,再结合云南省产业结构的历年纵向分析,旨在为云南省产业结构优化升级、经济发展方式转变提供科学参考．结果表明：1）云南省第一产业在产业结构和竞争力上均处于相对落后地位;2）云南省第二产业结构优势不明显,具备一定的竞争力优势,但同西部发达地区相比仍有一定差距;3）云南省第三产业结构优势明显,但竞争力优势不明显,产业结构优势未能很好的转化为竞争力优势;4）云南省应根据自身优势及存在问题,抓住机遇、制定对策,促进产业结构优化升级．     

杨房沟坝址高边坡工程地质特征及稳定性评价

为掌握杨房沟坝址高边坡稳定性情况及治理措施,采用现场调查及室内分析计算方法对河谷高边坡岩体工程地质特征及稳定性展开了全面研究。得出以下结论:高边坡花岗闪长岩可划分为块状、次块状及镶嵌结构等类型;边坡岩体质量从坡面向内分别为Ⅲ2、Ⅲ1、Ⅱ类,Ⅳ类岩体很少;天然边坡存在松动张裂、楔形体滑动及崩塌等破坏形式,控制性结构面为顺河向卸荷裂隙;从河谷演化角度通过数值模拟方法分析现今边坡应力分布、塑性区范围、变形规律及总体稳定性,认为坝址区天然边坡整体稳定性较好,降雨或地震等不利条件边坡可能存在浅部块体滑移失稳。     

基于浮游有孔虫重建的南海北部400 ka以来上层水体结构变化及其对东亚季风的响应

现代南海上层水体结构具有鲜明的季节特征,反映了季节性风场通过动力与热力过程施加的强烈影响;这种风场对上层水体结构的调控同样存在于地质历史时期,借此,长时间尺度上的东亚季风强度变化能够在南海沉积中留下记录,对相关高分辨率样品的研究继而可以从海洋的角度发掘出新的季风信息,成为对现有古季风资料的重要补充。本研究利用南海北部岩芯总长为50.8 m的MD12-3432站位（19°16.88'N,116°14.52'E;水深2125 m）高分辨率沉积样品,通过浮游有孔虫属种组合及其转换函数恢复了400 ka以来冬、夏季海水表层温度及温跃层深度,并对其进行频谱分析,同时对比现代观测资料及黄土粒度等古季风记录,讨论了海表温度、温跃层深度变化与东亚季风强度、表层环流格局等因素的关系。结果表明,晚更新世以来南海北部海表温度具有显著的100 ka冰期-间冰期旋回,冬季海表温度降幅可达8℃,是冰期冬季风增强与表层环流变化的共同结果。此外,冬季海表温度与温跃层深度重建结果均具有明显的67 ka周期,可能代表了东亚冬季风风速在南海北部的变化周期。同时,温跃层深度中未出现100 ka周期,可能指示冰期-间冰期旋回中表层环流的变化对其影响较弱,温跃层的加深主要由东亚冬季风的增强造成。