全文获取类型
收费全文 | 4203篇 |
免费 | 686篇 |
国内免费 | 942篇 |
专业分类
测绘学 | 855篇 |
大气科学 | 194篇 |
地球物理 | 1231篇 |
地质学 | 2384篇 |
海洋学 | 644篇 |
天文学 | 43篇 |
综合类 | 233篇 |
自然地理 | 247篇 |
出版年
2024年 | 7篇 |
2023年 | 29篇 |
2022年 | 89篇 |
2021年 | 112篇 |
2020年 | 146篇 |
2019年 | 190篇 |
2018年 | 149篇 |
2017年 | 193篇 |
2016年 | 188篇 |
2015年 | 190篇 |
2014年 | 237篇 |
2013年 | 320篇 |
2012年 | 301篇 |
2011年 | 348篇 |
2010年 | 244篇 |
2009年 | 303篇 |
2008年 | 320篇 |
2007年 | 317篇 |
2006年 | 342篇 |
2005年 | 271篇 |
2004年 | 261篇 |
2003年 | 214篇 |
2002年 | 154篇 |
2001年 | 133篇 |
2000年 | 144篇 |
1999年 | 121篇 |
1998年 | 77篇 |
1997年 | 81篇 |
1996年 | 73篇 |
1995年 | 47篇 |
1994年 | 63篇 |
1993年 | 33篇 |
1992年 | 31篇 |
1991年 | 18篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有5831条查询结果,搜索用时 125 毫秒
71.
72.
饱和软土压缩试验时,经常出现压缩曲线“反常”、压缩系数“倒大”的现象。它是土的原始结构发生破坏前后的不同压缩性的客观反映。饱和软土的结构力很微弱,唯质量好的原状土才能见到这种“反常”。应从成孔、取样、测试及资料整理等多个环节保证其工程意义。 相似文献
73.
Engineering geological studies and tunnel support design at Sulakyurt dam site, Turkey 总被引:2,自引:0,他引:2
H. Basarir 《Engineering Geology》2006,86(4):225-237
This paper presents the results of engineering geological investigations and tunnel support design studies, carried out at the Sulakyurt dam site, northeast of Ankara, Turkey. The Sulakyurt dam will be used for flow control and water storage for irrigation projects. Studies were carried out both in the field and the laboratory. Field studies include engineering geological mapping, intensive discontinuity surveying, core drilling and sampling for laboratory testing. The diversion tunnel will be driven in rock mass, consisting of granite and diorite. Empirical, analytical and numerical methods were combined for safe tunnel design. Rock mass rating (RMR), Rock mass quality (Q) and Geological strength index (GSI) systems were used for empirical rock mass quality determination, site characterization and support design. The convergence–confinement method was used as analytical method and software called Phase2, a 2D finite element program, was utilized as numerical method. According to the results acquired from the empirical, analytical and numerical methods, tunnel stability problems were expected in both granite and diorite rock masses. The support system, suggested by empirical methods, was applied and the performance of suggested support system was evaluated by means of numerical modelling. It was concluded that the suggested support systems were adequate, since after applying the suggested support system to granite and diorite, tunnel deformation and the yielded elements around the tunnel decreased significantly. Thus, it is suggested that for more reliable support design empirical, numerical and analytical methods should be combined. 相似文献
74.
根据自重湿陷性黄土的特点、《湿陷性黄土地区建筑规范》(GB50025—2004)和《建筑桩基技术规范》(JGJ94—94)中关于桩基设计的对比分析,通过自重湿陷性黄土场地工程实例分析计算,依据负摩擦产生的机理——中性点理论,论述了自重湿陷性黄土场地中桩基设计应考虑中性点,而不应全部计入负摩阻的观点。 相似文献
75.
76.
77.
As part of a broader process of inter-urban competition, city governments have increasingly sought to 'position' themselves as centres of creativity. In these branding initiatives, culture is viewed as a tool of urban regeneration and economic development. Our paper examines the case of Commerce Design Montréal, an annual design competition run by the City of Montréal, which aims to brand Montréal as a centre of design. Commerce Design Montréal is an example of a 'fast' policy initiated by the state, but carried out by business owners and citizens. As such, it represents a downloading of the responsibility for economic development to the private or individual scale and adopts only a partial view of the varied actors and uses that are implicated in the design process. The paper considers the opportunities and challenges that this model presents for promoting design as a form of urban regeneration in a neo-liberal context. 相似文献
78.
79.
80.
浅谈建筑设计与室内设计的联系与协调 总被引:1,自引:0,他引:1
李小睿 《南京气象学院学报》2005,28(4):556-558
针对现今在设计过程中建筑设计和室内设计的不协调,阐述了建筑设计和室内设计的相关概念及内在联系,分析了造成这种不协调的原因,并提出解决两者协调一致的方法。 相似文献