全文获取类型
收费全文 | 44021篇 |
免费 | 581篇 |
国内免费 | 274篇 |
专业分类
测绘学 | 1055篇 |
大气科学 | 2880篇 |
地球物理 | 8795篇 |
地质学 | 15217篇 |
海洋学 | 3767篇 |
天文学 | 10883篇 |
综合类 | 112篇 |
自然地理 | 2167篇 |
出版年
2021年 | 426篇 |
2020年 | 469篇 |
2019年 | 459篇 |
2018年 | 1045篇 |
2017年 | 948篇 |
2016年 | 1166篇 |
2015年 | 650篇 |
2014年 | 1130篇 |
2013年 | 2180篇 |
2012年 | 1280篇 |
2011年 | 1731篇 |
2010年 | 1538篇 |
2009年 | 2172篇 |
2008年 | 1806篇 |
2007年 | 1806篇 |
2006年 | 1684篇 |
2005年 | 1257篇 |
2004年 | 1259篇 |
2003年 | 1178篇 |
2002年 | 1125篇 |
2001年 | 1013篇 |
2000年 | 956篇 |
1999年 | 831篇 |
1998年 | 847篇 |
1997年 | 816篇 |
1996年 | 693篇 |
1995年 | 703篇 |
1994年 | 624篇 |
1993年 | 537篇 |
1992年 | 502篇 |
1991年 | 510篇 |
1990年 | 583篇 |
1989年 | 499篇 |
1988年 | 458篇 |
1987年 | 585篇 |
1986年 | 485篇 |
1985年 | 610篇 |
1984年 | 693篇 |
1983年 | 658篇 |
1982年 | 575篇 |
1981年 | 606篇 |
1980年 | 502篇 |
1979年 | 472篇 |
1978年 | 477篇 |
1977年 | 435篇 |
1976年 | 421篇 |
1975年 | 419篇 |
1974年 | 396篇 |
1973年 | 427篇 |
1971年 | 260篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Veselkin D. V. Tretyakova A. S. Senator S. A. Saksonov S. V. Mukhin V. A. Rozenberg G. S. 《Doklady Earth Sciences》2017,476(1):1113-1115
Doklady Earth Sciences - An analysis of data on the species abundance of flora in 89 cities (urban flora) of the Russian Federation facilitated determination of its main factors. It has been... 相似文献
122.
K. K. Edelshtein M. G. Grechushnikova Yu. S. Datsenko V. V. Puklakov 《Water Resources》2012,39(4):432-445
The objectives of diagnostic calculations using mathematical models of reservoirs are formulated. The structure of a box hydrological model GMV-MGU is described, and the results of calculation of daily water balance, internal heat exchange structure, and heat balance of individual areas in the Mozhaisk and Rybinsk reservoirs are given. First results of calculation of variations in mean daily phytoplankton biomass in the near-dam pool of a weakly eutrophic water body in period of spring (diatoms) and summer (blue-green) blooming are presented. 相似文献
123.
N. V. Kabychenko G. G. Kocharyan D. V. Pavlov A. N. Besedina 《Seismic Instruments》2012,48(3):214-217
A procedure for eliciting displacements in tidal waves from seismograms of broadband velocimeters like STS-2 and KSESH-R and the evaluation conversion of these displacements into vertical or volumetric deformation is proposed. 相似文献
124.
K. K. Edel’shtein A. V. Goncharov M. G. Ershova V. V. Puklakov N. G. Puklakova D. I. Sokolov 《Water Resources》2010,37(2):234-244
The methodological features and results of two soil surveys of the Senezh Reservoir carried out in 1992 and 2006 as a part
of multidisciplinary limnological studies of this large recreation water body with the aim to monitor its ecological state
and prepare recommendations for water protection measures are analyzed 相似文献
125.
126.
S.?V.?VyatkinEmail author G.?Yu.?Kriulina V.?K.?Garanin D.?G.?Koshchug E.?A.?Vasilyev 《Moscow University Geology Bulletin》2018,73(2):161-165
Two samplings of 65 diamond crystals divided by the intensity of a slow X-ray luminescence component are studied from the Arkhangel’skaya and Karpinskogo-1 pipes. IR and EPR spectroscopies revealed a relationship between the nitrogen A and P2 centers of the diamonds and the presence of a slow X-ray luminescence component. Its absence in most diamonds with high content of P1 (C) centers is explained by the low number of A and P2 centers. 相似文献
127.
128.
AbstractIt is frequently required to find whether a feature A of height h 0 will interrupt the view between two other features A1 and A2, of heights h 1 and h 2 respectively. Suppose that the right line from A1 to A2, whose zenith distance is ζ at A1, has a height h at A; it is then obvious that no more is necessary than to compute h and compare it with the known height h 0 of the feature A. 相似文献
129.
Summary A comparison is made between the multimode Rayleigh wave response to dip-slip fault-plane motion in earth models with and without a low-velocity channel in the upper mantle. In general, higher-mode amplitude spectra are useful for discriminating between the two types of structures. 相似文献
130.
An analysis is presented which seeks to reveal the possible causes for discrepancy in the results on the dependence of Cepheid amplitudes on star positions in the instability strip noted by different investigators.A comparison of the data used in two of these investigations—that of Yakimova (1970) and that of Sandage and Tammann (1971)—shows that it is most unlikely to be able to explain completely the conflicting results obtained in these studies. But if we analyse the data of Sandage and Tammann following the approach of Yakimova — namely, by considering the Cepheids in only one stellar system and taking into account the stellar colours in maximum light — we obtain Yakimova's result: the light amplitude is the larger, the nearer to the low temperature edge of the instability strip a Cepheid is. Therefore, it appears that differences between the various approaches contribute greatly to the different results of Sandage and Tammann and Yakimova (and the other investigators). 相似文献