全文获取类型
收费全文 | 991篇 |
免费 | 146篇 |
国内免费 | 38篇 |
专业分类
测绘学 | 391篇 |
大气科学 | 61篇 |
地球物理 | 176篇 |
地质学 | 214篇 |
海洋学 | 48篇 |
天文学 | 7篇 |
综合类 | 131篇 |
自然地理 | 147篇 |
出版年
2024年 | 8篇 |
2023年 | 11篇 |
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 20篇 |
2019年 | 22篇 |
2018年 | 12篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 18篇 |
2014年 | 40篇 |
2013年 | 48篇 |
2012年 | 62篇 |
2011年 | 55篇 |
2010年 | 38篇 |
2009年 | 64篇 |
2008年 | 70篇 |
2007年 | 60篇 |
2006年 | 68篇 |
2005年 | 65篇 |
2004年 | 51篇 |
2003年 | 61篇 |
2002年 | 56篇 |
2001年 | 46篇 |
2000年 | 42篇 |
1999年 | 36篇 |
1998年 | 33篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 5篇 |
1993年 | 12篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有1175条查询结果,搜索用时 15 毫秒
71.
Susceptibility assessment of earthquake-triggered landslides in El Salvador using logistic regression 总被引:13,自引:0,他引:13
This work has evaluated the probability of earthquake-triggered landslide occurrence in the whole of El Salvador, with a Geographic Information System (GIS) and a logistic regression model. Slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness are the predictor variables used to determine the dependent variable of occurrence or non-occurrence of landslides within an individual grid cell. The results illustrate the importance of terrain roughness and soil type as key factors within the model — using only these two variables the analysis returned a significance level of 89.4%. The results obtained from the model within the GIS were then used to produce a map of relative landslide susceptibility. 相似文献
72.
73.
74.
75.
76.
77.
广州城市规划信息网中的WebGIS方案设计与应用 总被引:5,自引:0,他引:5
王俊 《地球信息科学学报》2000,2(3):32-37
本文介绍广州市城市规划局规划信息网的GIS信息发布系统建设方案,本方案采用ESRI公司IMS 2 .0作为GIS发布服务器端软件,建立基于CGI的Web GIS系统,使用户实现WWW交互。本文从系统的硬件要求与软件需求以及服务器端服务应用程序、Web页面的开发等方面阐述了系统的建立与应用。 相似文献
78.
The Tau Model for Data Redundancy and Information Combination in Earth Sciences: Theory and Application 总被引:3,自引:0,他引:3
Sunderrajan Krishnan 《Mathematical Geosciences》2008,40(6):705-727
Many decision-making processes in the Earth sciences require the combination of multiple data originating from diverse sources.
These data are often indirect and uncertain, and their combination would call for a probabilistic approach. These data are
also partially redundant with each other or with all others taken jointly. This overlap in information arises due to a variety
of reasons—because the data arises from the same geology, because they originate from the same location or the same measurement
device, etc. The proposed tau model combines partially redundant data, each taking the form of a prior probability for the
event being assessed to occur given that single datum. The parameters of that tau model measure the additional contribution
brought by any single datum over that of all previously considered data; they are data sequence-dependent and also data value-dependent.
Data redundancy depends on the sequence in which the data is considered and also on the data values themselves. However, for
a given sequence, averaging the tau model parameters over all possible data values leads to exact analytical expressions and
corresponding approximations and inference avenues. Information on multiple-point connectivity of permeability arrives from
core data, well-test data and seismic data which are defined over varying supports with complex redundancy between these information
sources. In order to compute these tau weights for determining connectivity, one needs a model of data redundancy, here expressed
as a vectorial training image (Ti) constructed using a prior conceptual knowledge of geology and the physics of data measurement.
From such a vectorial Ti, the tau weights can be computed exactly. Neglecting data redundancy leads to an over-compounding
of individual data information and the possible risk of making extreme decisions. 相似文献
79.
从太湖流域旱涝史料看历史气候信息处理 总被引:14,自引:1,他引:14
历史气候信息处理建立在信息提取的基础上,目的在于建立一套方法,将定性的历史气候信息转化为气候变化参数,并消除各种不均—性,从而建立历史气候序列。本文着重介绍建立太湖流域历史旱涝等级序列的方法与步骤: 1)确立信息源,建立信息网络;2)站点等级的确定与订正;3)弱信息处理;4)信息的综合。 相似文献
80.