全文获取类型
收费全文 | 381篇 |
免费 | 65篇 |
国内免费 | 58篇 |
专业分类
测绘学 | 20篇 |
大气科学 | 1篇 |
地球物理 | 68篇 |
地质学 | 375篇 |
海洋学 | 3篇 |
天文学 | 1篇 |
综合类 | 25篇 |
自然地理 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 19篇 |
2015年 | 10篇 |
2014年 | 25篇 |
2013年 | 13篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 26篇 |
2009年 | 30篇 |
2008年 | 22篇 |
2007年 | 25篇 |
2006年 | 28篇 |
2005年 | 26篇 |
2004年 | 29篇 |
2003年 | 19篇 |
2002年 | 14篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 9篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1979年 | 1篇 |
排序方式: 共有504条查询结果,搜索用时 390 毫秒
161.
162.
163.
Quantitative comparison of river inflows to a rapidly expanding lake in central Tibetan Plateau
下载免费PDF全文
![点击此处可从《水文研究》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The recent rapid expansion of inland lakes on the Tibetan Plateau (TP) are a good indicator of the consequences of climate change. Quantifying the hydrological cycle of the lake basin is fundamentally important to understand the causes of lake growth. However, the hydrological processes of the TP interior are very complex and difficult to investigate because of the lack of observations. This is especially true for estimating the lake changes when run‐off inflows are affected by small lakes located in the flow routes within drainage areas. We used an integrated hydrological model, in combination with glacier melt and lake retention models, to analyse the run‐off inflows to Lake Siling Co, the largest endorheic lake in Tibet. It includes four subdrainage basins: Zhajiazangbu, Zhagenzangbu, Alizangbu, and Boquzangbu. Lake Siling Co was characterized by considerable increases during warm season from 1981 to 2012, due to the increased run‐off from Zhajiazangbu accounting for about 51–62% of the total run‐off inflows. Moreover, the dramatic increases exhibited during cold seasons were related to the increased retention water released from the small lakes within Zhagenzangbu and Alizangbu. Of the studied subdrainage basins, Boquzangbu contributed the least during both warm and cold seasons. On average, the annual amount of evaporation from lakes within the drainage area was about 2 times greater than that of glacier melt run‐off. Our results suggest that the retention effects of lakes on river inflows should receive more attention, because understanding these effects is potentially crucial to improved understanding of lake variations in the TP. 相似文献
164.
鄂东南大冶矿区地质环境影响性评价 总被引:2,自引:0,他引:2
在我国,矿业城市的地质环境问题日趋严重,需要探索一套适合于区域矿山地质环境影响性评价的技术方法,以指导矿业城市或重点矿区的矿产资源开发和环境保护。以鄂东南大冶矿区(即大冶市)为例,以遥感调查数据为基础,建立了由地质环境背景、已有地质环境问题和矿山开采活动三方面组成的区域矿山地质环境影响性评价指标体系,采用传统的模糊综合评价方法,分别对自然状态下矿区的地质灾害易发性和采矿状态下的矿区地质环境影响性进行了定量评价。结果表明:(1)自然状态下,大冶矿区地质灾害高易发区、较高易发区、较低易发区及低易发区分别占评价总面积的3.29%、12.55%、24.53%及59.62%;(2)采矿状态下,大冶矿区地质环境影响性严重区、较严重区、一般、轻微区分别占评价总面积的13.63%、22.96%、33.95%及24.96%。评价结果可作为大冶矿区矿产开发规划和综合性地质环境治理的重要依据。 相似文献
165.
166.
167.
本文对普定猫洞乡可处村地质灾害的成因进行了分析评价,并讨论了其地质灾害形成机制,提出了针对性的防治对策,为地质灾害防治提供了科学依据。 相似文献
168.
169.
Artificial lowering of the groundwater level in dolomitic aquifers of the Far West Rand gold mining area has led to the formation
of hundreds of sinkholes and subsidences. Where ground movements develop in or around important structures, it has become
standard practice to drill boreholes for exploration and to inject mine tailings (slimes), cement and water to fill cavernous
zones and arrest further ground movements. Although this method of grouting has mostly been effective, some boreholes accepted
such large quantities of grout that the operation became prohibitively expensive. This paper describes an experiment to construct
subsurface barriers by pouring wet (high slump) concrete via closely-spaced lines of boreholes into cavernous zones beneath
a depression on a provincial road. The barriers required a small quantity of concrete and the zone between barriers was quickly
filled by grout. The lack of further ground movements confirmed the success of the project.
Received: 22 May 2000 · Accepted: 18 July 2000 相似文献
170.
矿产资源开发的地质环境影响及其治理对策——以北京首钢铁矿环境治理与保护措施为例 总被引:1,自引:0,他引:1
开发矿产资源创造大量财富的同时,也对矿区生态环境产生了严重的负面影响。本文概述了我国矿产资源开发对地质环境造成的普遍影响。通过分析了北京首钢铁矿“三废”防治、地质环境治理和生态修复的成功经验,总结了矿山地质环境治理与保护的方法和措施,提出了加强矿山环境保护的对策和建议。 相似文献