Geochemical and Mineral Characteristics of Jurassic Volcanic Rocks from ODP Sites 304, 1149, and 801: Implications for Magmatic Evolution in the Northwest Pacific     

CHEN Shuangshuang  LIU Jiaqi  Patrick RIOUAL  GUO Zhengfu 《《地质学报》英文版》2018,92(3):915-934

The regular variations in magmatic activities along the Northwest Pacific plate have been little studied in spite of their importance. In this contribution, systematic analyses were conducted on tholeiitic basalts from three Ocean Drilling Program sites (Sites 304, 1149, and 801), including the petrographic features, major and trace elements, Nd isotopic compositions, and mineral structure and compositions of whole rocks. Volcanic rocks from Sites 304, 1149, and 801 belong to tholeiites and exhibit depleted light rare earth elements (LREE), large ion lithophile elemental contents (LILE), and relatively depleted Nd isotopic ratios (143Nd/144Nd=0.513139–0.513211), similar to those of normal mid-ocean ridge basalts (N-MORB). Comprehensive data on mineral compositions, whole-rock geochemistry, and geochronology demonstrate that a regular variation trend exists in the north-south direction along the Northwest Pacific plate. The 143Nd/144Nd values (0.513139–0.513211) and trace-element ratios for whole rocks (Sm/Th=15.35–30.00; Zr/Hf=28.53–35.76; Zr/Y=2.58–3.67; Th/La=0.04–0.06; Th/Y=0.33–0.70), as well as the trace-element ratios (Zr/Hf, La/Yb, Ti/Zr) of clinopyroxenes from Sites 1149 and 801 tholeiites show larger variations compared to those from Site 304 tholeiites (143Nd/144Nd=0.513185–0.513195; Sm/Th=18.19–20.58; Zr/Hf=31.07–33.26; Zr/Y=2.62–3.03; Th/La=0.05–0.06; Th/Y=0.48–0.57). Mineral zoning textures were obvious in tholeiites from Sites 1149 and 801 but were rarely observed in Site 304. These regular features were likely attributed to the differences in the heterogeneity of the magma source, the process of magmatic evolution, the plate-spreading rate, and the effective and ineffective mixing.  相似文献   

知识密集型服务业空间关联特征及其动力机制分析——基于广东省21个地级市的实证   总被引：4，自引：3，他引：1  

方远平  毕斗斗  谢蔓  林彰平 《地理科学》2014,(10)

以转型中的经济大省广东为例,运用探索性空间数据分析法和空间常系数模型,分析广东省知识密集型服务业(KIBS)发展水平的地区差异、空间关联特征及其动力机制,研究结论表明:1广东省各地级市KIBS产出总体上以珠三角城市最高,但各行业存在空间差异;2广东省地级市KIBS呈空间正相关特点,但空间结构极不平衡,呈"总体分散、局部集中"分布格局,珠三角内诸城市属于KIBS热点区域,是高值集聚区,粤东西北的大部分城市是位于冷点区域,4 a间没有突破低值集聚的现状,也揭示了珠三角地区内相邻城市的KIBS具有竞争性,尚未形成有效的扩散-协同的发展格局;3广东省KIBS空间格局的动力因子分析表明:城市化、工业化、信息化、经济外向度和交通通达性均对KIBS发展有促进作用,而市场需求对KIBS发展产生负向影响。  相似文献   

The Channel ecosystem,a cross-roads of anthropogenic pressures and scientific studies: Lessons learned from the European INTERREG IV projects (2009–2015)     

《Marine Policy》2016

The English Channel hosts a high density of human activities, which result in strong pressures and impacts on its marine ecosystem. The European Union's INTERREG programme funds projects to promote sustainable development through ecosystem-based management and the development of socio-economic services in the Channel region. An analysis of the themes studied during INTERREG IVA projects to date reveals both gaps that should be addressed in the future, as well as good practices that should be maintained and promoted. This analysis was used to provide advice and recommendations on knowledge gaps which may form the foundation of future projects for European programmes such as those in the next INTERREG project call (2015–2020).  相似文献   

Neighborhood impacts on household participation in payments for ecosystem services programs in a Chinese nature reserve: A methodological exploration     

ZHANG Huijie  AN Li  BILSBORROW Richard  CHUN Yongwan  YANG Shuang  DAI Jie 《地理学报(英文版)》2021,31(6):899-922

Payments for Ecosystem Services(PES)programs have been implemented in both developing and developed countries to conserve ecosystems and the vital services they provide.These programs also often seek to maintain or improve the economic wellbeing of the populations living in the corresponding(usually rural)areas.Previous studies suggest that PES policy design,presence or absence of concurrent PES programs,and a variety of socioeconomic and demographic factors can influence decisions of households to participate or not in the PES program.However,neighborhood impacts on household participation in PES have rarely been addressed.This study explores potential neighborhood effects on villagers'enrollment in the Grain-to-Green Program(GTGP),one of the largest PES pro-grams in the world,using data from China's Fanjingshan National Nature Reserve.We utilize a fixed effects logistic regression model in combination with the eigenvector spatial filtering(ESF)method to explore whether neighborhood size affects household enrollment in GTGP.By comparing the results with and without ESF,we find that the ESF method can help ac-count for spatial autocorrelation properly and reveal neighborhood impacts that are otherwise hidden,including the effects of area of forest enrolled in a concurrent PES program,gender and household size.The method can thus uncover mechanisms previously undetected due to not taking into account neighborhood impacts and thus provides an additional way to account for neighborhood impacts in PES programs and other studies.  相似文献   

多模态数据的地质图关联网络构建及知识服务     

邱芹军  段雨希  田苗  吴麒瑞  马凯  陶留锋  谢忠 《地质论评》2024,70(2):2024020022-2024020022

地质图件及其附属资源（如描述文本）作为地质知识的重要存储媒介,蕴含着大量的地学知识及专家经验知识及隐式知识。快速精准地对多模态地质数据进行知识规范化定义、形式化表达、语义化关联和精准化推理是目前地学知识抽取及挖掘的前沿。当前,海量的地学数据中图件及附属描述信息知识分布零散,图件中的信息无法有效地与描述信息进行关联并提供知识服务。本文以多模态地质数据为数据源,建立了多源数据驱动下的地质图知识表达模型,通过地质基础知识、规则知识及决策知识来表达图件中蕴含的显隐式地质知识,从语义、空间、属性三个维度表示地质对象间的关系;并基于领域知识针对地质图件及描述信息开展了地质实体及关系的精准抽取及存储研究,最后以江西省于都县银坑幅G50E011007图幅150000矿产地质调查矢量数据为例进行了验证与分析,实验结果验证了本文所提出的知识表达模型及知识抽取方法, 能够较好地解决地质知识建模中图文关联弱、知识挖掘不充分等问题。  相似文献   

多元化思维在电视气象节目策划中应用的探讨          下载免费PDF全文

王茜  侯亚红  王慧瑜  马虹旭 《气象与环境学报》2007,23(3):42-46

探讨了如何将电视化思维、共鸣思维、个性思维、创新思维理念综合运用到电视气象节目策划中,以提高电视气象节目质量和收视率,为气象节目与电视艺术的有效融合提供多元化思维方式。  相似文献   

What happens after climate change adaptation projects end: A community-based approach to ex-post assessment of adaptation projects     

《Global Environmental Change》2023

Over the last decade, hundreds of climate change adaptation projects have been funded and implemented. Despite the importance of these first-generation adaptation projects for establishing funders and implementors’ “best practices,” very little is known about how early adaptation projects have endured, to what ends, and for whom. In this article, I propose a community-based methodology for ex-post assessment of climate change adaptation projects. This methodology contributes to recognitional justice by asking the individuals and collectives tasked with sustaining adaptation initiatives to define adaptation success and what criteria for success should be assessed. I apply this subjective assessment approach in 10 communities across Ecuador that participated in an internationally funded adaptation project that concluded in 2015. My analysis draws together participatory mapping, walking interviews with local leaders, participant observation, and surveys with former project participants. The results highlight that even adaptation projects that were deemed highly successful at their closure have uncertain futures. I find that the sustainability mechanisms that were envisioned by project implementors have not functioned, and communities are shouldering the burden of reviving failing adaptation interventions. These findings highlight that the current model of episodic funding for climate change adaptation projects and evaluation processes needs to be revisited to acknowledge the long-term challenges faced by communities. This analysis also calls attention to the importance of ex-post assessment for adaptation projects and the potential of subjective assessment approaches for building more ontological and epistemological pluralism in understandings of successful climate change adaptation.  相似文献   

工程地质优势面理论观点概要与认识          下载免费PDF全文

罗国煜 《江苏地质》2008,32(1):1-4

通过50年来的工程地质教学、研究和工程实践,形成了一个研究模式——优势面分析观点。优势面观点是建立在岩体结构控制论基础上的创新,在认识深化并立足于学科交叉上的综合发现,因此能较系统地解决实际问题。特别是20世纪90年代后期以来,优势面理论在水电、桥梁、矿山和地下工程等大型工程中取得了很多应用成果和新进展。工程地质环境岩土工程学科,强调地质、力学、工程三个要素的有机结合,作为定性和定量分析手段的结合,优势面研究有利于解决本学科的科学问题和实际问题。通过“二环,二悬,三基,一优势面”的观点、思路和方法,去研究城市环境土工安全问题,促进学科向前发展。  相似文献