全文获取类型
收费全文 | 15956篇 |
免费 | 3820篇 |
国内免费 | 2063篇 |
专业分类
测绘学 | 598篇 |
大气科学 | 1790篇 |
地球物理 | 12701篇 |
地质学 | 4111篇 |
海洋学 | 595篇 |
天文学 | 58篇 |
综合类 | 1274篇 |
自然地理 | 712篇 |
出版年
2024年 | 46篇 |
2023年 | 192篇 |
2022年 | 413篇 |
2021年 | 643篇 |
2020年 | 561篇 |
2019年 | 664篇 |
2018年 | 604篇 |
2017年 | 610篇 |
2016年 | 514篇 |
2015年 | 687篇 |
2014年 | 852篇 |
2013年 | 864篇 |
2012年 | 884篇 |
2011年 | 961篇 |
2010年 | 862篇 |
2009年 | 1135篇 |
2008年 | 882篇 |
2007年 | 1013篇 |
2006年 | 982篇 |
2005年 | 968篇 |
2004年 | 847篇 |
2003年 | 806篇 |
2002年 | 675篇 |
2001年 | 628篇 |
2000年 | 576篇 |
1999年 | 542篇 |
1998年 | 526篇 |
1997年 | 484篇 |
1996年 | 500篇 |
1995年 | 467篇 |
1994年 | 402篇 |
1993年 | 291篇 |
1992年 | 234篇 |
1991年 | 146篇 |
1990年 | 107篇 |
1989年 | 82篇 |
1988年 | 73篇 |
1987年 | 26篇 |
1986年 | 21篇 |
1985年 | 8篇 |
1984年 | 17篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 23篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1954年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
131.
132.
The Florida State University (FSU) multimodel superensemble forecast is evaluated against several other operational weather models for the Southeast Asia region. The superensemble technique has demonstrated its exceptional skills in forecasting precipitation, motion and mass fields compared to either individual global operational or ensemble mean forecasts. The motion field investigation for the season of 2001 reveals that the superensemble forecasts are closer to the observed data compared to the other global member operational models through its low systematic errors at the 850 hPa level. The FSU multimodel superensemble forecasts exhibit the lowest root mean square errors (RSMEs), the highest correlation against the best observed data and the lowest systematic errors compared to the other operational model members. These forecasts have the potential to provide better daily weather predictions over the Southeast Asia region, particularly during the early northeast monsoon that often causes heavy rainfall in the equatorial part of the Southeast Asia region. 相似文献
133.
The Dahuiyeh (Zarand) earthquake of 2005 February 22 in central Iran: reactivation of an intramountain reverse fault 总被引:3,自引:0,他引:3
134.
Zoltán Wéber 《Geophysical Journal International》2006,165(2):607-621
135.
Matthew J. Spittal Frank H. Walkey John McClure Richard J. Siegert Kimberley E. Ballantyne 《Natural Hazards》2006,39(1):15-29
Preparedness is a key dependent variable in many studies examining people’s response to disasters such as earthquakes. A feature
of many studies on this issue, however, is the lack of attention given to psychometric issues when constructing measures of
preparedness. With regard to earthquake preparation, for example, many studies could be greatly improved by the use of a valid
and reliable measure of preparedness. This research developed such a measure that assessed both low-level preparedness, such
as having an emergency kit, and high-level preparedness, such as altering home structures to mitigate damage. Studies of Wellington
(New Zealand) residents using two samples totalling n=652 showed that 23 items measuring these different aspects of earthquake preparation could be combined into a reliable, valid,
unifactorial scale. This brief scale should have utility in multivariate studies of earthquake preparation, either as a dependent
variable, where preparation is the outcome variable of primary interest, or as one of several independent variables, where
preparation and other measures predict another outcome variable. 相似文献
136.
Seismic Hazards Assessment for Radioactive Waste Disposal Sites in Regions of Low Seismic Activity 总被引:4,自引:0,他引:4
Clark H. Fenton John Adams Stephen Halchuk 《Geotechnical and Geological Engineering》2006,24(3):579-592
A comparative tectonic quiescence and lack of earthquakes make the stable centres of continents attractive for siting long-term
radioactive waste storage facilities. The low rates of deformation in such regions, however, make it difficult to characterize
their long-term seismotectonic behaviour, leading to uncertain estimates for the very low probability hazard estimates required
by society. In an attempt to overcome the deficiency of both contemporary seismicity and paleoseismic data in central Canada,
we have used earthquake histories from regions with similar seismotectonic characteristics from around the world. Substituting
space for time, we estimate a long-term rate per 106 km2 of 0.004 magnitude ≥6 earthquakes per annum, of which 33–100% might rupture to the surface. 相似文献
137.
A shakemap system providing rapid estimates of strong ground shaking could be useful for emergency response providers in a
damaging earthquake. A hybrid procedure, which combines site-dependent ground motion prediction models and the limited observations
of the Real-Time Digital stream output system (RTD system operated by Central Weather Bureau, CWB), was set up to provide
a high-resolution shakemap in a near-real-time manner after damaging earthquakes in Taiwan. One of the main factors that affect
the result of ground motion prediction analysis is the existence of site effects. The purpose of this paper is to investigate
the local site effects and their influence in the ground shaking and then establish an early estimation procedure of potential
hazard for damaging earthquakes. Based on the attenuation law, the site effects of each TSMIP station are discussed in terms
of a bias function that is site and intensity-level dependent function. The standard deviation of the site-dependent ground
motion prediction model can be significantly reduced. The nonlinear behavior of ground soil is automatically taken into account
in the intensity-level dependent bias function. Both the PGA and the spectral acceleration are studied in this study. Based
on the RTD data, event correctors are calculated and applied to precisely estimate the shakemap of damaging earthquakes for
emergency response. 相似文献
138.
基于预测的边缘检测方法 总被引:3,自引:0,他引:3
提出了一种基于预测的、有一定自适应性的边缘检测方法。介绍了其原理和算法实现过程。通过计算两个相邻像素的灰度值的均值、均方差和梯度来预测下一个像素的灰度值,比较预测值和真实值来判断下一个像素是否是边界点。通过与现有同类算法的比较,证明了该算法的优越性。 相似文献
139.
地震属性分析中水平切片的应用 总被引:6,自引:0,他引:6
利用地震数据体中含有的丰富地质信息,可以有效地进行储层预测。层拉平水平切片地层学解释方法是先将地震剖面目的层段做层拉平处理,然后对切片顺地层层面追踪,勾绘出各种地层现象,并以地层学的观点加以解释。该方法在吉林探区扶新南部地区的应用中,对于识别河道的展布趋势取得了较好的效果,而且发现了多期叠置的扇型沉积体。另外,还可指导反演数据体的解释,做到对岩性体从定性到定量的描述。 相似文献
140.
现阶段地表油气化探技术难题与发展对策 总被引:2,自引:1,他引:2
虽然地表油气化探方法技术已取得显著的应用效果, 但是由于成功率计算标准不同及方法技术本身的缺陷, 导致人们对方法的认同度较低。当前, 地表油气化探技术的发展, 一方面要以可靠的实验依据、严谨的数理推导及理论模型应对来自方法技术本身的挑战, 另一方面也要利用其快速、廉价和直接的优势, 加强与地质、遥感、非震物探等方法综合应用。 相似文献