首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   262009篇
  免费   5389篇
  国内免费   3452篇
测绘学   7184篇
大气科学   19638篇
地球物理   54748篇
地质学   91834篇
海洋学   22242篇
天文学   55895篇
综合类   1050篇
自然地理   18259篇
  2021年   2225篇
  2020年   2647篇
  2019年   2880篇
  2018年   4540篇
  2017年   4124篇
  2016年   6269篇
  2015年   4301篇
  2014年   7007篇
  2013年   14341篇
  2012年   6948篇
  2011年   8674篇
  2010年   7597篇
  2009年   10267篇
  2008年   9062篇
  2007年   8629篇
  2006年   9796篇
  2005年   7972篇
  2004年   7906篇
  2003年   7411篇
  2002年   6938篇
  2001年   6049篇
  2000年   5670篇
  1999年   4834篇
  1998年   4888篇
  1997年   4689篇
  1996年   4253篇
  1995年   4343篇
  1994年   4029篇
  1993年   3784篇
  1992年   3537篇
  1991年   3540篇
  1990年   3647篇
  1989年   3345篇
  1988年   3174篇
  1987年   3735篇
  1986年   3280篇
  1985年   4141篇
  1984年   4647篇
  1983年   4326篇
  1982年   4233篇
  1981年   3860篇
  1980年   3601篇
  1979年   3436篇
  1978年   3447篇
  1977年   3235篇
  1976年   2981篇
  1975年   2907篇
  1974年   2873篇
  1973年   3074篇
  1972年   1992篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Izvestiya, Physics of the Solid Earth - Abstract—This work generalizes the classical mathematical model of fluid and gas filtration in a fractured-porous medium. It results in a generalized...  相似文献   
992.
Izvestiya, Physics of the Solid Earth - Abstract—This paper considers daily, seasonal, and interannual variations of natural potentials at two sites in the cryolithozone at the testing...  相似文献   
993.
Izvestiya, Physics of the Solid Earth - Abstract—A detailed study has been carried out regarding temporal variations of seismicity in the region of Greece’s eastern coast of the Aegean...  相似文献   
994.
Izvestiya, Physics of the Solid Earth - An Erratum to this paper has been published: https://doi.org/10.1134/S1069351322100019  相似文献   
995.
Izvestiya, Physics of the Solid Earth - An Erratum to this paper has been published: https://doi.org/10.1134/S1069351322090014  相似文献   
996.
Meisina  C.  Bonì  R.  Bozzoni  F.  Conca  D.  Perotti  Cesare  Persichillo  Pina  Lai  C. G. 《Bulletin of Earthquake Engineering》2022,20(11):5601-5632
Bulletin of Earthquake Engineering - Mapping the susceptibility of earthquake-induced soil liquefaction at the continental scale is a challenge. Susceptibility of soils to liquefaction is the...  相似文献   
997.
Nair  M. Anjali  Amrutha  M. M.  Kumar  V. Sanil 《Ocean Dynamics》2022,72(2):151-168
Ocean Dynamics - The study presents the assessment of spectral wave conditions in the coastal waters of the central west coast of India based on data from waverider buoys at two locations during...  相似文献   
998.
Ocean Dynamics - An analytical solution to the problem of the Cyprus warm core Eddy generation over the bottom topography non-axisymmetric perturbations in the broad area of the Eratosthenes...  相似文献   
999.
Wu  Shitou  Yang  Yueheng  Roberts  Nick M. W.  Yang  Ming  Wang  Hao  Lan  Zhongwu  Xie  Bohang  Li  Tianyi  Xu  Lei  Huang  Chao  Xie  Liewen  Yang  Jinhui  Wu  Fuyuan 《中国科学:地球科学(英文版)》2022,65(6):1146-1160
Science China Earth Sciences - U?Pb geochronology of calcite using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is an emerging method, with potential applications...  相似文献   
1000.
We present a narrative of the eruptive events culminating in the cataclysmic January 15, 2022 eruption of Hunga Tonga-Hunga Ha'apai Volcano by synthesizing diverse preliminary seismic, volcanological, sound wave, and lightning data available within the first few weeks after the eruption occurred. The first hour of eruptive activity produced fast-propagating tsunami waves, long-period seismic waves, loud audible sound waves, infrasonic waves, exceptionally intense volcanic lightning and an unsteady volcanic plume that transiently reached—at 58 ?km—the Earth's mesosphere. Energetic seismic signals were recorded worldwide and the globally stacked seismogram showed episodic seismic events within the most intense periods of phreatoplinian activity, and they correlated well with the infrasound pressure waveform recorded in Fiji. Gravity wave signals were strong enough to be observed over the entire planet in just the first few hours, with some circling the Earth multiple times subsequently. These large-amplitude, long-wavelength atmospheric disturbances come from the Earth's atmosphere being forced by the magmatic mixture of tephra, melt and gasses emitted by the unsteady but quasi-continuous eruption from 0402±1–1800 UTC on January 15, 2022. Atmospheric forcing lasted much longer than rupturing from large earthquakes recorded on modern instruments, producing a type of shock wave that originated from the interaction between compressed air and ambient (wavy) sea surface. This scenario differs from conventional ideas of earthquake slip, landslides, or caldera collapse-generated tsunami waves because of the enormous (~1000x) volumetric change due to the supercritical nature of volatiles associated with the hot, volatile-rich phreatoplinian plume. The time series of plume altitude can be translated to volumetric discharge and mass flow rate. For an eruption duration of ~12 ?h, the eruptive volume and mass are estimated at 1.9 ?km3 and ~2 900 ?Tg, respectively, corresponding to a VEI of 5–6 for this event. The high frequency and intensity of lightning was enhanced by the production of fine ash due to magma—seawater interaction with concomitant high charge per unit mass and the high pre-eruptive concentration of dissolved volatiles. Analysis of lightning flash frequencies provides a rapid metric for plume activity and eruption magnitude. Many aspects of this eruption await further investigation by multidisciplinary teams. It represents a unique opportunity for fundamental research regarding the complex, non-linear behavior of high energetic volcanic eruptions and attendant phenomena, with critical implications for hazard mitigation, volcano forecasting, and first-response efforts in future disasters.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号