首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   117篇
  免费   10篇
  国内免费   8篇
测绘学   21篇
大气科学   5篇
地球物理   11篇
地质学   52篇
海洋学   17篇
综合类   4篇
自然地理   25篇
  2023年   1篇
  2021年   6篇
  2020年   1篇
  2019年   9篇
  2018年   2篇
  2017年   9篇
  2016年   8篇
  2015年   5篇
  2014年   2篇
  2013年   11篇
  2012年   8篇
  2011年   7篇
  2010年   8篇
  2009年   7篇
  2008年   4篇
  2007年   11篇
  2006年   5篇
  2005年   3篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2001年   7篇
  2000年   2篇
  1999年   4篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1994年   2篇
  1992年   1篇
  1988年   2篇
  1984年   1篇
排序方式: 共有135条查询结果,搜索用时 15 毫秒
51.
Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas (Yuanzigou delta and Bulianghe delta) on the margins of Daihai Lake were surveyed to compare and contrast stacking patterns using aerial photographs, field trenching and sediment sampling. Shallow cores and trench data collected from the margins of Daihai Lake indicate that a variety of depositional processes have been active since Daihai Lake formed. Two 3-D sedimentation models which employ chronostratigraphic correlation technique were generated. The chronostratigraphic sedimentation models predict and represent the architectures and sand-body continuity of sediments. Stratigraphical coincidence of the broad sheeted drifts and channel erosion suggests a coupling between downslope and alongslope processes. Distributary mouth bars are prevalent in the front of deltas on steeper slopes due to the dominance of down-slope flows. On the contrary, the along-slope currents favor the development of distal bar deposits with sheeted sandbodies on gentle depositional slopes. This study provides an insight into the architecture of complex sedimentary facies associated with highlighting key differences between downslope flows and alongslope currents. The distribution of sand within these deltas is of particular interests, with applications in understanding the architecture of hydrocarbon reservoirs formed in lacustrine rift basin.  相似文献   
52.
三角洲平原高弯曲分流河道内部结构单元三维建模   总被引:1,自引:0,他引:1  
以大庆萨尔图油田北三区西部西块SⅡ12小层典型三角洲平原高弯曲分流河道为例,进行了三角洲平原高弯曲分流河道内部结构单元建模。首先根据高弯曲分流河道沉积层次性,以及河流弯曲机理,解剖了分流河道内部结构,识别出点坝以及侧积层单元,提取了侧积层形态参数和统计参数。其次采用椭球形方程建立了侧积层平面数学函数表达式,采用直线方程描述侧积层剖面形态,从而建立侧积层空间三维几何形态。最后,分两步建立了高弯度分流河道内部结构单元三维地质模型。首先采用序贯指示建模建立分流河道微相模型;随后根据侧积层数学模型描述侧积层空间分布。并在分流河道微相内部将侧积层模型嵌入,形成精细的高弯曲分流河道内部结构模型。以此思路为指导建立了SⅡ12小层结构模型,以此结构模型为基础的储层参数模型很好地再现了点坝内部侧积层对流体渗流的遮挡,为油藏数值模拟和剩余油挖潜奠定了基础。  相似文献   
53.
储层构型研究方法简介   总被引:3,自引:0,他引:3  
构型研究是沉积学和储集层地质学目前一个重要的新的研究方法。它把过去二维的模式转化为三维的模式,对解决储集层(体)的不均匀性提出了新的途径。该方法是著名河流沉积学家Miall(1985,1988)提出的。现不少学者运用该方法解决各地区的沉积学和储集层(体)的问题。构型研究从选择构型体到构型单元的研究,直到运用,已有系统的理论和步骤。本文为提倡和推广该方法,向研究者们作一系统介绍。  相似文献   
54.
辽河油田锦99块扇三角洲前缘储层层次分析   总被引:1,自引:0,他引:1       下载免费PDF全文
辽河油田锦99块沙河街组四段上亚段杜家台油层是典型的扇三角洲前缘沉积,主要由扇三角洲前缘水下分流河道和河道砂坝组成。依据高分辨率层序地层学和储层构型理论,采用层次分析方法,对锦99块沙四上亚段扇三角洲前缘砂体构型界面进行了层次表征。综合利用岩心资料和测井资料,识别出11种岩相类型和4种岩相组合。根据高频湖泛面、冲刷面、粒序突变面和岩相转换面将沙四上亚段Ⅰ3砂层组和Ⅱ1砂层组划分为6个短期旋回、15个超短期旋回。在等时格架内,建立了扇三角洲前缘储层5级构型界面层次,层次界面以三级和四级为主,四级界面分布较稳定,三级界面零星分布。总结出两种层次界面分布模式:较稳定分布的界面和随机型分布的界面。储层层次分析为研究区构型约束建模提供了依据。  相似文献   
55.
Canada is a typical maritime country, fisheries economic prosperity and marine sustainable development have been the main management and research work. From two perspectives of research literatures and latest strategic plans, this paper studied the ocean research priorities and hot trends of Canada. The study found that the marine science and technology in Canada focuses on marine populations and ecosystems, protection of the marine environment and species, marine monitoring and data information, marine technology and management tools, Climate change and arctic research, deep-sea material energy and driving mechanisms. In the future, Canada will continue further study on arctic research, global warming, ecosystem monitoring, deep-sea exploration, marine new energy and new technologies. In summary, Canada’s research situations and development trends may provide a useful reference to China’s development of the marine industry.  相似文献   
56.
当前,在建筑结构设计中存在着设计深度不够、图面质量差、违反规范条文、结构方案不合理、经济性差、存有安全隐患等问题。究其原因,既有设计单位质量意识淡漠、质量保证体系不健全、设计人员自身技术水平低等内部因素,也有社会质量监管不完善、市场各主体信用缺失以及不合理干预等外部因素。作为设计质量管理的主体,设计单位应当强化质量意识,建立健全质量保证体系与质量奖惩制度,不断提高设计人员的技术水平;结构设计人员应该重视对规范的理解与应用,注重结构概念设计和结构方案优化,对结构进行切实合理的计算分析,减少错、漏、碰、缺,确保建筑结构设计质量的不断提高。  相似文献   
57.
制约建筑设计企业开展工程总承包业务的主要因素   总被引:2,自引:0,他引:2  
我国目前建筑设计企业的EPC总承包业务举步维艰,文章回顾了改革开放后我国基本建设管理体制的发展历程,并从资质及市场管理、核心竞争力、人才和资金、管理体系等角度阐述了制约建筑设计企业开展工程总承包业务的主要因素。  相似文献   
58.
The influence of environmental familiarity on spatial knowledge development in the context of campuses and their surrounding environments has been well documented. However, existing studies have rarely stressed the distinction between the architectural styles of a campus and its surrounding environment. This study thus targets a campus with a historical architectural style that contrasts strongly with the surrounding modern environment, to gain a fresh view on how spatial knowledge develops with environmental familiarity on such a unique campus. This study recruited 30 freshmen and 28 sophomores to complete landmark selection, route sketching, and distance estimation tasks used to measure their spatial knowledge. The results mainly revealed that spatial knowledge developed by freshmen and sophomores stayed at a similar level as no significant differences were detected. As such, the key implication of this study is that spatial knowledge could be developed to the largest cognitive extent within a short period (i.e., 1.5 months) after students have entered a new campus in which the architectural style contrasts strongly with its surrounding environment. Increased environmental familiarity did not significantly promote their spatial knowledge development as sophomores with about an added year of campus stay performed similarly to freshmen.  相似文献   
59.
A revival has occurred in the use of historical architectural styles for modern suburban houses but this has attracted little attention from journalists and academics. Those who have noted it disagree about when it began and gathered momentum. Newspaper and trade journal evidence for Canadian cities indicates that the revival began in the late 1960s; that it has reached market saturation; and that Victorian and neo-classical styles became dominant after 1980. Coinciding with the beginnings of inner-city gentrification, the historicist revival in suburban dwellings preceded the recent interest in neotraditional urban design. Not a fringe taste, it says something about the zeitgeist.  相似文献   
60.
地震应急预案是地震应急管理工作的基础和首要环节,应急预案的信息管理系统的开发对该工作的数字化、规范化和信息化十分重要。本文对地震应急预案管理信息系统的研制开发过程进行了技术回顾,介绍了工作思路和技术方案,并简要说明了地震应急预案管理信息系统的功能及使用。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号