全文获取类型
收费全文 | 46939篇 |
免费 | 577篇 |
国内免费 | 436篇 |
专业分类
测绘学 | 939篇 |
大气科学 | 2760篇 |
地球物理 | 8727篇 |
地质学 | 17898篇 |
海洋学 | 4618篇 |
天文学 | 10981篇 |
综合类 | 110篇 |
自然地理 | 1919篇 |
出版年
2022年 | 466篇 |
2021年 | 734篇 |
2020年 | 757篇 |
2019年 | 853篇 |
2018年 | 1735篇 |
2017年 | 1614篇 |
2016年 | 1758篇 |
2015年 | 818篇 |
2014年 | 1597篇 |
2013年 | 2652篇 |
2012年 | 1813篇 |
2011年 | 2220篇 |
2010年 | 2050篇 |
2009年 | 2460篇 |
2008年 | 2090篇 |
2007年 | 2277篇 |
2006年 | 2067篇 |
2005年 | 1220篇 |
2004年 | 1148篇 |
2003年 | 1108篇 |
2002年 | 1141篇 |
2001年 | 1014篇 |
2000年 | 905篇 |
1999年 | 741篇 |
1998年 | 747篇 |
1997年 | 728篇 |
1996年 | 612篇 |
1995年 | 588篇 |
1994年 | 584篇 |
1993年 | 453篇 |
1992年 | 465篇 |
1991年 | 438篇 |
1990年 | 489篇 |
1989年 | 382篇 |
1988年 | 368篇 |
1987年 | 429篇 |
1986年 | 367篇 |
1985年 | 489篇 |
1984年 | 452篇 |
1983年 | 430篇 |
1982年 | 444篇 |
1981年 | 360篇 |
1980年 | 387篇 |
1979年 | 359篇 |
1978年 | 360篇 |
1977年 | 295篇 |
1976年 | 288篇 |
1975年 | 295篇 |
1974年 | 285篇 |
1973年 | 314篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
101.
E. K. Semenov N. N. Sokolikhina E. V. Sokolikhina 《Russian Meteorology and Hydrology》2013,38(10):661-668
The genetic and synoptic classifications of the Novorossiysk Bora are created using the data of daily observations at the Novorossiysk meteorological station and other available synoptic information. Obtained are the quantitative criteria of these classifications, and on this base worked out are the basic scenarios of the generation and evolution of this dangerous phenomenon on the Black Sea coast of Russia. According to the genetic classification, the Bora was divided into four types: frontal, air-mass, monsoon, and gravity. Quantitative criteria worked out for each type can be used for the more accurate forecast of this destructive phenomenon near Novorossiysk. According to the synoptic classification, four classes were distinguished: Azores, North Atlantic, Siberian, and Arctic. 相似文献
102.
G. S. Ripp A. G. Doroshkevich M. V. Badmatsyrenov N. S. Karmanov 《Geochemistry International》2007,45(6):538-545
The composition and nature of high-Cr minerals in lithic clasts from the carbonatites of the Veseloe occurrence, northern Transbaikalia, were considered. In order to determine their source, the Cr-bearing phases were compared with chromite, magnetite, and rutile from ultrabasic rocks, mantle xenoliths, and eclogites. It was suggested that the xenoclasts studied were formed at great depths, whereas the carbonatites were directly derived from the mantle rather than formed by the crustal differentiation of a silicate-carbonate melt. 相似文献
103.
104.
105.
106.
Current and future wide field surveys in infrared passbands present opportunities for ultra low‐mass stellar sample selection via proper motions, as well as or instead of purely photometric techniques. Furthermore, proper motion measurements yield additional clues as to candidate membership of cluster or field (kinematic) populations. In this paper we review some recent results and speculate as to the possibilities afforded by the next generation of wide‐field infrared surveys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
107.
A collection of brachiopods by the Institute of Oceanology, Academia Sinica (Qingdao), contains eight species from seven genera.
Six of the species have been recorded previously from China seas—Lingula adamsi, L. anatina, Discinisca stella, Pelagodiscus atlanticus, Campages mariae, Terebratalia coreanica. Two species (Terebratulina hataiana andFrenulina sanguinolenta) have been described from other parts of the Pacific area. The apparent absence of any endemic species is a noteworthy feature
of Chinese in comparison with Japanese faunas. 相似文献
108.
A. E. Volvach A. A. Berezhnoi L. N. Volvach I. D. Strepka E. A. Volvach 《Bulletin of the Crimean Astrophysical Observatory》2011,107(1):122-124
Investigations on OH maser lines in comets have been performed with the RT-22 at CrAO. The results of observations of 9P/Temper1
and Lulin C/2007 N3 comets in the OH molecule line at a wavelength of 18 cm are presented. An original technique for observation
data analysis has been developed. The gas production rate of OH molecules in these comets is estimated. 相似文献
109.
I. B. Safarov 《Izvestiya Physics of the Solid Earth》2006,42(3):260-270
The elastic and density properties of rocks of the Shamakha-Ismailly seismogenic blocks are studied by the ultrasonic pulse method in quasi-hydrostatic high pressure apparatuses. An attempt is made to more accurately determine the upper crustal lithology of these blocks. The observed values of the elastic and density characteristics of the rocks at high pressures suggest that the upper layers in the Ismailly and Shamakha blocks can consist of sedimentary carbonate rocks such as marls, sandstones, mudstones, and limestones. The middle layers apparently consist of volcaniclastic rocks: lithoclastic tuffs, andesites, etc. The lower layer (basement) in both blocks is likely composed of basic rocks such as basalts, trachybasalts, etc. According to the values of elastic wave velocities and densities, gabbroid rocks may compose the fourth layer of the Buinuz intrusion, identified from seismic data. 相似文献
110.
V. G. Eselevich V. M. Bogod I. V. Chashey M. V. Eselevich Yu. I. Yermolaev 《Geomagnetism and Aeronomy》2009,49(1):133-135
The solar sources of the magnetic storms of November 8 and 10, 2004, are analyzed. The preliminary results of such an analysis [Yermolaev et al., 2005] are critically compared with the results of the paper [Tsurutani et al., 2008], where solar flares were put in correspondence with these magnetic storms. The method for determining solar sources that cause powerful magnetospheric storms is analyzed. It has been indicated that an optimal approach consists in considering coronal mass ejections (CMEs) as storm sources and accompanying flares as additional information about the location of CME origination. 相似文献