盐酸及乙酸介质中的碳酸盐岩溶蚀表面特征及机理——以南堡凹陷为例   总被引：1，自引：0，他引：1  

朱文慧  曲希玉  邱隆伟  陈勇  龚发雄  吴思萱 《矿物岩石地球化学通报》2015,(3)

为了研究酸性条件下碳酸盐岩的溶蚀表面特征及机理,以南堡凹陷及周边凸起区10个典型碳酸盐岩样品为研究对象,进行乙酸和盐酸溶液的溶解实验,并通过扫描电镜观察样品的溶蚀特征。结果显示,岩石结构和矿物成分的选择性溶蚀,是碳酸盐岩溶蚀过程中的主要作用形式;方解石和白云石均存在特有的溶蚀现象,即"溶蚀晶锥"方解石和"蜂窝状"白云石,为晶体选择性溶蚀的产物;表生条件下,灰岩中少量白云石的加入能够增加方解石的溶解度,白云石的含量上限为13%,超过该界限,随白云石含量的增加,溶蚀作用减弱。  相似文献   

“鱼·菜·菌”生态养殖模式氮磷转化及去除效果分析   总被引：2，自引：0，他引：2  

薛凌展 《亚热带资源与环境学报》2014,(4):15-25

设计了一种由空心菜、异育银鲫＂中科3号＂和微生物膜组成的浮床生态养殖系统,采用水生空心菜根系及浮床为基质,构建了以池塘土著微生物和外源微生物为菌源的池塘漂浮式微生物膜,并结合水生空心菜对养殖水体进行原位修复。定期跟踪监测3种养殖模式水体中总磷和总氮的变化情况,结果显示：＂鱼·菜·菌＂培育模式YCJ-2的水质较为稳定,与对照组YCJ-3相比,总氮和总磷分别降低了66.13%和43.81%;总氮排放浓度达到淡水养殖废水排放二级标准,总磷排放浓度介于淡水养殖废水排放一级标准和地表水质量Ⅴ类标准之间,该模式对养殖水体中的总氮和总磷的去除率效果明显。分别采用物料平衡原理和产量法检测分析不同模式的产排污系数和沉积物产污系数,结果显示：对照组YCJ-3总氮和总磷产排污系数最高,分别为1.60 g·kg^-1和19.90 g·kg^-1;YCJ-2沉积物总磷和总氮产污系数最低仅为1.01 g·kg^-1和0.35 g·kg^-1,分别比YCJ-3降低了82.5%和83.17%;养殖效益分析结果显示：＂鱼·菜·菌＂培育模式YCJ-2总产值达到3 536.04元/100 m2,比YCJ-3和YCJ-1（鱼-菜培育模式）模式养殖经济效益分别提高了49.12%和11.88%。  相似文献   

省级国土资源“一张图”数据中心建设探讨          下载免费PDF全文

冯永玉 《山东国土资源》2014,30(11)

从国土资源"一张图"数据中心亟待解决的问题入手,结合山东省国土资源数据中心建设实际,从国土资源数据建设的宏观和规划层面,探讨国土资源"一张图"数据中心的定位、与国土资源各业务系统的关系和科学合理的建设步骤等方面问题,为构建覆盖"横向到边、纵向到底、联动更新、资源共享"的国土资源"一张图"数据中心提供理论支撑。  相似文献   

Precipitation anomalies,economic production,and the role of “first-nature” and “second-nature” geographies: A disaggregated analysis in high-income countries     

《Global Environmental Change》2020

Linkages between hydroclimate variability and economic development are often theorized to be present only in developing economies. Using spatially small-scaled data from multiple decades for European regions, we examine the relationship between precipitation anomalies and economic performance in highly developed economic systems. We conduct a disaggregated empirical analysis to mitigate the bias potentially arising from spatial aggregation because precipitation realizations tend to vary drastically within larger sized economic units. We modify original precipitation indices to capture the dynamic expectation formation of economic agents about climate conditions to measure deviations from these anticipated environmental states. Using panel model regressions in a quasi-experimental research design, we analyse whether deviations from average growth rates of aggregated economic output are potentially non-linearly related to the magnitude of precipitation deviations from the anticipated climate norm within regions, after accounting for any shocks common to all regions. We find that precipitation deviations that exceed critical thresholds (intermediate anomalies) for both unusually dry and unusually wet years reduce regional growth rates. The adverse impacts are more pronounced for overly dry periods. Importantly, the relationship between economic growth and precipitation anomalies is not generalizable across all regions. Natural geographical circumstances such as prevailing climatic conditions (“first-nature” geographies) and human-made socio-economic factors such as sector structure and income level (“second-nature” geographies) moderate the anomaly response. The empirical findings substantiate the necessity to incorporate precipitation variability into the assessment of economic costs of climate change; not only in developing countries or agricultural societies but also in highly developed economic systems. Moreover, the empirical results have important implications for policy makers as uneven effect sizes at the subnational level suggest that policy measures should be targeted in space and coordinated between national and regional levels of government.  相似文献   

广东省国土资源“一张图”信息体系建设与应用     

吴永静  万宝林  蔡娟娟  俞建  姚静  方晓乐 《测绘与空间地理信息》2015,(10):112-115

广东省国土资源"一张图"信息体系建设与应用包括国土资源核心数据库、综合管理平台、信息服务网站、应用中间件和典型应用案例等多方面的建设,以及配套的标准与技术规范的研究。目的是全面、快速和准确地掌握全省土地、矿产等各类资源的总体布局,做到资源状况"一览无余",为国土资源政务管理、资源的全程监控监管提供持续有力的数据支撑,为各级政府部门、社会行业及公众提供国土资源信息公开共享服务。采用了海量数据管理、组件式开发、数据保密处理及共享服务等多种技术,具备灵活性高、实用性强的特点,已在国土、气象、水利等部门率先开展了典型应用建设,形成了成熟共享应用模式,为后续的应用推广奠定了坚实的基础,具有良好的前景。  相似文献   

论《孔疏》之“兴”     

安性栽 《广东海洋大学学报》2005,25(2):103-107

通过对《孔疏》标“兴”之特点与《毛诗传》《郑笺》标“兴”之特点比较分析,提出《孔疏》之标“兴”主要着眼于“兴”与作品主旨之间的关系,而没有特别注重标“兴”的位置。这些特点使得《孔疏》之“兴”开始从政治化逐渐转向文学化。  相似文献   

三肇凹陷断层垂向分段生长与扶杨油层油源断层的厘定   总被引：1，自引：0，他引：1       下载免费PDF全文

王海学  付晓飞  付广  吕延防  杜微  刘桐汐 《地球科学》2014,39(11):1539-1546

野外观察、典型地震解剖和物理模拟证实, 只要岩石存在能干性差, 断层具有典型垂向分段生长特征.岩石能干性差异决定断层演化历经3个阶段: 下部断层形成、断裂上下分段和贯通性断裂形成.以三肇凹陷为例, 应用岩石力学特征和断层相关褶皱理论, 证实扶杨油层砂岩层段普遍形成断裂, 青一段泥岩阻止下部断层向上传播, 从而形成断层垂向分段生长现象.结合油藏精细解剖表明, 三肇凹陷扶杨油层"倒灌"运移的主要油源断层是成藏期活动、沟通源储且垂向分段生长的断裂.   相似文献   

“人-地-业”协同视角下乡村旅游投资与目的地空间作用研究     

李涛 《地理研究》2022,41(12):3259-3272

随着中国乡村旅游产业迅速发展,乡村旅游投资加快增长,给乡村地域人地关系和空间格局带来了深刻变革。本研究从“人-地-业”协同视角,在认识乡村旅游投资内涵及其“主体-要素-对象”体系基础上,剖析乡村旅游投资空间作用的“投资-产业-空间”传导过程,理论化构建乡村旅游地空间结构演化的二阶梯级模式,探索性揭示乡村旅游投资目的地空间作用过程与机制。乡村旅游投资空间作用是目的地“人-地-业”系统环境影响投资主体区位选择与决策,引起产业投资要素流动和投资对象布局变化,造成当地产业发展空间不均衡、人地关系地域系统和“三生”功能格局演化的结果。以期,研究发现从微观尺度深化旅游投资与旅游地空间作用理论,拓展乡村旅游地空间演化理论内涵,为指导乡村旅游高质量发展和乡村旅游地高水平建设与更好推进乡村振兴提供理论借鉴。  相似文献   

Bayesian analysis of zero inflated spatiotemporal HIV/TB child mortality data through the INLA and SPDE approaches: Applied to data observed between 1992 and 2010 in rural North East South Africa     

《International Journal of Applied Earth Observation and Geoinformation》2013

Longitudinal mortality data with few deaths usually have problems of zero-inflation. This paper presents and applies two Bayesian models which cater for zero-inflation, spatial and temporal random effects. To reduce the computational burden experienced when a large number of geo-locations are treated as a Gaussian field (GF) we transformed the field to a Gaussian Markov Random Fields (GMRF) by triangulation. We then modelled the spatial random effects using the Stochastic Partial Differential Equations (SPDEs). Inference was done using a computationally efficient alternative to Markov chain Monte Carlo (MCMC) called Integrated Nested Laplace Approximation (INLA) suited for GMRF. The models were applied to data from 71,057 children aged 0 to under 10 years from rural north-east South Africa living in 15,703 households over the years 1992–2010. We found protective effects on HIV/TB mortality due to greater birth weight, older age and more antenatal clinic visits during pregnancy (adjusted RR (95% CI)): 0.73(0.53;0.99), 0.18(0.14;0.22) and 0.96(0.94;0.97) respectively. Therefore childhood HIV/TB mortality could be reduced if mothers are better catered for during pregnancy as this can reduce mother-to-child transmissions and contribute to improved birth weights. The INLA and SPDE approaches are computationally good alternatives in modelling large multilevel spatiotemporal GMRF data structures.  相似文献   

Assembling insurgent citizenship: immigrant advocacy struggles in the Washington DC metropolitan area     

Helga Leitner  Christopher Strunk 《Urban geography》2013,34(7):943-964

This article examines the political and spatial registers of struggles against exclusionary local immigration policies and for more welcoming policies in the Washington DC metropolitan area, one of the hotspots for both local anti-immigration policies and immigrant advocacy in the United States. We conceptualize immigrant advocacy not simply as an alliance, but instead as an assemblage that brings together a diverse set of differently positioned actors and nonhuman actants. The assemblage enacts a diverse politics that deploys different forms of activism, while engaging different publics (e.g., religious communities, unions, the larger public sphere in public spaces, etc.) and the state in complex ways. From acting outside the state to engaging in claims-making towards the state, immigrant advocates are making claims and actions that challenge and go beyond dominant conceptions of citizenship rights and liberal democratic politics. The spatial register is similarly diverse. The immigrant advocacy assemblage is confronted with and enacts a different politics of place in central cities and inner- and outer-ring suburbs. Contestations of exclusionary local policies, however, are not simply about a local politics of place. To the contrary, some actors and actants in the assemblage are actively involved in extra-local networking, collaborating across jurisdictional boundaries—between central cities and inner-and outer-ring suburbs within the Washington DC metropolitan area and across the United States. The complexities of these contestations call into question post-political narratives of “proper” politics, underscoring the need for an empirically grounded critical theory of democracy. This article contributes to this task by providing a geographically and historically sensitive analysis of the immigrant advocacy assemblage.  相似文献