全文获取类型
收费全文 | 61294篇 |
免费 | 379篇 |
国内免费 | 1057篇 |
专业分类
测绘学 | 2089篇 |
大气科学 | 3700篇 |
地球物理 | 11510篇 |
地质学 | 25943篇 |
海洋学 | 4535篇 |
天文学 | 10400篇 |
综合类 | 2259篇 |
自然地理 | 2294篇 |
出版年
2022年 | 491篇 |
2021年 | 724篇 |
2020年 | 786篇 |
2019年 | 869篇 |
2018年 | 6353篇 |
2017年 | 5459篇 |
2016年 | 4179篇 |
2015年 | 855篇 |
2014年 | 1508篇 |
2013年 | 2079篇 |
2012年 | 2578篇 |
2011年 | 4546篇 |
2010年 | 3762篇 |
2009年 | 4247篇 |
2008年 | 3609篇 |
2007年 | 4281篇 |
2006年 | 1798篇 |
2005年 | 1096篇 |
2004年 | 1217篇 |
2003年 | 1197篇 |
2002年 | 992篇 |
2001年 | 811篇 |
2000年 | 683篇 |
1999年 | 432篇 |
1998年 | 461篇 |
1997年 | 475篇 |
1996年 | 337篇 |
1995年 | 359篇 |
1994年 | 336篇 |
1993年 | 281篇 |
1992年 | 285篇 |
1991年 | 290篇 |
1990年 | 337篇 |
1989年 | 272篇 |
1988年 | 258篇 |
1987年 | 260篇 |
1986年 | 191篇 |
1985年 | 301篇 |
1984年 | 302篇 |
1983年 | 296篇 |
1982年 | 274篇 |
1981年 | 269篇 |
1980年 | 282篇 |
1979年 | 204篇 |
1978年 | 242篇 |
1977年 | 204篇 |
1976年 | 184篇 |
1975年 | 185篇 |
1974年 | 171篇 |
1973年 | 207篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
V. A. Lutskii 《Seismic Instruments》2009,45(1):69-74
The results of determining the relative number of recorded oscillograms for acoustic event intensities of up to 400 1/s in the four-channel Aline32D system for acoustic data reception and processing are presented. Since the internal characteristics of a computer determining the data processing performance are not always available, this problem is solved experimentally. Recommendations concerning the determined working parameters of the Aline32D system are given. This work may be used for the solution of geophysical applied problems. 相似文献
142.
In the present study, we discuss the application of microwave-irradiated pyrolysis of municipal solid waste (MSW) for total
recovery of useful gases and energy. The MSW pyrolysis under microwave irradiation highly depends on the process parameters,
like microwave power, microwave absorbers, and time of irradiation. The thoroughness of pyrolysis and product recovery were
studied by changing the abovesaid variables. Pyrolysis of MSW occurs in the power rating range of 450–850 W—outside this power
rating range, pyrolysis is not possible. Experiments were carried out using various microwave absorbers (i.e., graphite, charcoal,
and iron) to enhance the pyrolysis even at lower power rating. The results show that the pyrolysis of MSW was possible even
at low power ratings. The major composition of the pyrolysis gaseous product were analyzed with GC–MS which includes CO2, CO, CH4, etc. 相似文献
143.
V. A. Zakhozhay 《Astrophysics and Space Science》2008,315(1-4):13-19
This paper calculates the stellar–substellar initial mass function (IMF) based on data from low-luminosity stars and substars. We find the mass spectrum for the stars and substars less than 10 million years in age, and we estimate the low-mass part of the stellar–substellar IMF for 10 million years ago. 相似文献
144.
Doklady Earth Sciences - Large-scale atmosphere–ocean interaction in the Atlantic sector of the Arctic Ocean is analyzed. New studies demonstrate that the variability of Atlantic water inflow... 相似文献
145.
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
146.
147.
148.
149.
Kozoderov V. V. Kondranin T. V. Dmitriev E. V. 《Izvestiya Atmospheric and Oceanic Physics》2017,53(9):1132-1141
Izvestiya, Atmospheric and Oceanic Physics - The basic model for the recognition of natural and anthropogenic objects using their spectral and textural features is described in the problem of... 相似文献
150.