全文获取类型
收费全文 | 309篇 |
免费 | 29篇 |
国内免费 | 15篇 |
专业分类
测绘学 | 92篇 |
大气科学 | 48篇 |
地球物理 | 77篇 |
地质学 | 27篇 |
海洋学 | 56篇 |
天文学 | 7篇 |
综合类 | 25篇 |
自然地理 | 21篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 10篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 16篇 |
2016年 | 14篇 |
2015年 | 5篇 |
2014年 | 14篇 |
2013年 | 29篇 |
2012年 | 17篇 |
2011年 | 15篇 |
2010年 | 21篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 26篇 |
2006年 | 22篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 17篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有353条查询结果,搜索用时 15 毫秒
1.
应急管理部多层级视频会议系统跨网段转发技术 总被引:2,自引:1,他引:1
介绍应急管理部视频会议系统接入地震系统的基本情况,结合地震应急视频会议系统应用现状,分析多层级跨网视频会议系统的架构特点,着重分析跨网段"背靠背"转发优化技术方案在视频会议系统融合中的实现与应用,以期为类似的应用场景提供参考。 相似文献
2.
Andrew Curtis Jayakrishnan Ajayakumar Eric Jefferis Susanne Mitchell 《International journal of geographical information science》2019,33(6):1224-1250
ABSTRACTThe importance of including a contextual underpinning to the spatial analysis of social data is gaining traction in the spatial science community. The challenge, though, is how to capture these data in a rigorous manner that is translational. One method that has shown promise in achieving this aim is the spatial video geonarrative (SVG), and in this paper we pose questions that advance the science of geonarratives through a case study of criminal ex-offenders. Eleven ex-offenders provided sketch maps and SVGs identifying high-crime areas of their community. Wordmapper software was used to map and classify the SVG content; its spatial filter extension was used for hot spot mapping with statistical significance tested using Monte Carlo simulations. Then, each subject’s sketch map and SVG were compared. Results reveal that SVGs consistently produce finer spatial-scale data and more locations of relevance than the sketch maps. SVGs also provide explanation of spatial-temporal processes and causal mechanisms linked to specific places, which are not evident in the sketch maps. SVG can be a rigorous translational method for collecting data on the geographic context of many phenomena. Therefore, this paper makes an important advance in understanding how environmentally immersive methods contribute to the understanding of geographic context. 相似文献
3.
M. Bergmann T. SoltwedelM. Klages 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(6):711-723
Although megafaunal organisms play an important role in deep benthic ecosystems and contribute significantly to benthic biomass in the Arctic little is known about their temporal dynamics. Here, we assessed the interannual dynamics of megafaunal organisms from the HAUSGARTEN observatory in the Fram Strait, an area where the effects of climatic forcing are particularly evident. We analysed three congruent camera transects taken in 2002, 2004 and 2007. Environmental parameters were measured in order to be able to put our faunal results into an environmental context.Our results indicate that although the densities of megafaunal species show different patterns over time, most exhibit an overall decrease between 2002 and 2007 and total megafaunal densities decreased regularly from 2002 to 2004 to 2007 (12.16±0.96 to 7.41±0.43 ind m−2). This concurs with a steady increase in bottom-water temperatures and a decrease in the total organic content and microbial biomass of surficial sediments at the same time period. Although suspension feeder densities also decreased, predator/scavenger and deposit feeder densities have declined to such an extent that suspension feeders accounted for almost 100% of the megafauna in 2007. It could thus be argued that the trophic diversity at the central HAUSGARTEN station (2500 m) has decreased. Temperature-related changes in the production of the surface layers may lead to changes in the quality and/or quantity of particles exported to the deep seafloor. The densities of deposit feeders (i.e. holothurians) peaked (1.14±0.13 ind m−2) in 2004, the year following the longest ice cover. These results indicate the importance of ice-related export of particles to the deep seafloor and highlight the need for time-series transects, especially in an era when productive marginal ice zones tend to disappear with the receding sea ice. Although there is a general consensus that the Arctic is in a transition towards a warmer state, only continued observation will allow us to assess if the interannual changes observed are a result of decadal cycles related to the Arctic and North Atlantic Oscillation or if they are indicators of long-term change. 相似文献
4.
曹铁朋 《测绘与空间地理信息》2021,44(4):84-87
土地是支撑城市社会经济发展和基础设施建设的空间基础,作为自然物的土地具有价值属性。土地储备涉及市土地开发中心前期部、征地部、出让部、工程部、合同部、计财部等内部职能部门,涉及测绘、规划、房管、农业、城市更新、发改、人民政府等外部单位,交互业务较多,因此土地的规划、审批、征收、出让、工程等流程复杂、管理困难。本文介绍了土地储备业务管理系统的实现思路,系统实现建立业务审批体系。规范资金使用和管理,达到海量数据高效处理、图属档一体化、实时信息在线共享、流程优化协同办理、短信督办提醒的目标,满足对土地储备情况的宏观监管和微观审批,形成完善的土地储备业务管理体系。 相似文献
5.
《Geoforum》2015
The paper offers a critical intervention into the debates on research impact, theorising the potential of underpinning research agendas by ethics of care. We explore how a range of vectors of care, both intimate and distant, emerged in collaborative activities between researchers based in the UK and community youth workers and teenage female carers in Slovakia, leading to a series of (un)expected outcomes. We argue that while all research impacts cannot be planned in advance, an ethics of care embedded in relationships within and beyond research settings may form conditions in which outcomes exceeding the initial expectations can be anticipated. To achieve this, we argue for questioning the distinctions between academic and non-academic collaborators, legitimising diverse forms of knowledge, action and impact in institutional policies, and for conceiving research projects from the beginning as “more-than-research” avenues. 相似文献
6.
7.
探讨网络视频应用于建设工程监管领域的系统建设,介绍了系统框架、数据建设、功能设计和技术路线,以重庆市重点建设工程为例进行项目开发并在建委系统取得了试用,最后指出全过程、多传感、集成的体制性建设工程监管系统是未来趋势。 相似文献
8.
Wenwen Li Sizhe Wang 《International journal of geographical information science》2017,31(8):1562-1582
The increasing research interest in global climate change and the rise of the public awareness have generated a significant demand for new tools to support effective visualization of big climate data in a cyber environment such that anyone from any location with an Internet connection and a web browser can easily view and comprehend the data. In response to the demand, this paper introduces a new web-based platform for visualizing multidimensional, time-varying climate data on a virtual globe. The web-based platform is built upon a virtual globe system Cesium, which is open-source, highly extendable and capable of being easily integrated into a web environment. The emerging WebGL technique is adapted to support interactive rendering of 3D graphics with hardware graphics acceleration. To address the challenges of transmitting and visualizing voluminous, complex climate data over the Internet to support real-time visualization, we develop a stream encoding and transmission strategy based on video-compression techniques. This strategy allows dynamic provision of scientific data in different precisions to balance the needs for scientific analysis and visualization cost. Approaches to represent, encode and decode processed data are also introduced in detail to show the operational workflow. Finally, we conduct several experiments to demonstrate the performance of the proposed strategy under different network conditions. A prototype, PolarGlobe, has been developed to visualize climate data in the Arctic regions from multiple angles. 相似文献
9.
近年来我国大部分地区在冬、春两季多遭受冻雨灾害,自动气象站的风向风速传感器容易因冻结而无法正常工作。针对冻结故障的实时检测问题,本文设计了一种基于ZQZ-TF型风传感器的故障自动检测装置。该装置通过检测风传感器的工作电压和工作电流,实现对传感器实时状态的监控。同时,结合具体的故障诊断算法,能够快速判断风传感器是否被冻结。系统的核心硬件电路、软件算法可分别集成在自动气象站风向风速数据采集电路和嵌入式软件中,具有结构紧凑、操作简单的特点。经验证,该装置能够实时检测风传感器冻结故障,且工作稳定,检测精度高。 相似文献
10.