全文获取类型
收费全文 | 151166篇 |
免费 | 230篇 |
国内免费 | 145篇 |
专业分类
化学 | 58009篇 |
晶体学 | 2341篇 |
力学 | 8963篇 |
综合类 | 18篇 |
数学 | 30570篇 |
物理学 | 51640篇 |
出版年
2021年 | 498篇 |
2020年 | 554篇 |
2019年 | 760篇 |
2018年 | 10205篇 |
2017年 | 11120篇 |
2016年 | 5887篇 |
2015年 | 1645篇 |
2014年 | 1644篇 |
2013年 | 2797篇 |
2012年 | 6570篇 |
2011年 | 14964篇 |
2010年 | 9439篇 |
2009年 | 9542篇 |
2008年 | 13167篇 |
2007年 | 16679篇 |
2006年 | 2381篇 |
2005年 | 8417篇 |
2004年 | 4607篇 |
2003年 | 4421篇 |
2002年 | 2406篇 |
2001年 | 1283篇 |
2000年 | 1526篇 |
1999年 | 881篇 |
1998年 | 944篇 |
1997年 | 872篇 |
1996年 | 673篇 |
1995年 | 621篇 |
1994年 | 569篇 |
1993年 | 508篇 |
1992年 | 542篇 |
1991年 | 603篇 |
1990年 | 570篇 |
1989年 | 577篇 |
1988年 | 554篇 |
1987年 | 583篇 |
1986年 | 569篇 |
1985年 | 640篇 |
1984年 | 667篇 |
1983年 | 565篇 |
1982年 | 564篇 |
1981年 | 587篇 |
1980年 | 550篇 |
1979年 | 608篇 |
1978年 | 649篇 |
1977年 | 593篇 |
1976年 | 665篇 |
1975年 | 534篇 |
1974年 | 514篇 |
1973年 | 575篇 |
1967年 | 451篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Differential Equations - For a spectrally controllable linear autonomous system with incommensurable delays, we construct a dynamic state feedback in the form of a differential-difference... 相似文献
2.
Filatova S. M. Guseva M. K. Bodrova T. G. Parshina D. V. Budanova U. A. Sebyakin Yu. L. 《Russian Journal of General Chemistry》2022,91(1):S13-S23
Russian Journal of General Chemistry - The review article traces the main trends of the synthetic approach to the solution of the problem of overcoming the resistance of pathogenic bacterial... 相似文献
3.
JETP Letters - Extraordinary multiparticle effects in quantizing magnetic fields that are manifested in strongly interacting two-dimensional electron systems in MgZnO/ZnO heterostructures have been... 相似文献
4.
Kuz’mina L. G. Navasardyan M. A. Kalle P. Bezzubov S. I. 《Crystallography Reports》2021,66(3):420-423
Crystallography Reports - The crystal and molecular structures of Cl–C6H4–O–C16H33 (I) have been studied, and its differential scanning calorimetry (DSC) study is performed.... 相似文献
5.
The health monitoring has been studied to ensure integrity of design of engine structure by detection, quantification, and prediction of damages. Early detection of faults may allow the downtime of maintenance to be rescheduled, thus preventing sudden shutdown of machines. In cylinder pressure developed, vibrations and noise emissions data provide a rich source of information about condition of engines. Monitoring of vibrations and noise emissions are novel non-intrusive methodologies for which positioning of various transducers are important issue. The presented work shows applicability of these diagnosis methodologies adopted in case of diesel engines. The effects of changing various fuel injection parameters was analyzed. Scope of using non-intrusive technique has been analyzed by changing locations of microphone. Novelty of this worklies in exploring signal processing methods for various locations around the engine test set up. Various frequency ranges of contributing noise and vibration sources were identified. Time-Frequency analysis showed the onset of various cyclic. Based on the identification of various frequency bands, it is possible to device suitable filters in order to extract more information. 相似文献
6.
Daulbaev O. Isaenko L. I. Bogdzel’ A. A. Lobanov S. I. Krinitsyn P. G. Milkov V. M. Belushkin A. V. 《Crystallography Reports》2022,67(3):464-469
Crystallography Reports - Two LiInSe2 single crystals, grown under different conditions, have been studied. Characteristics of these crystals for neutron detection have been compared using... 相似文献
7.
Radiophysics and Quantum Electronics - A well-known simplified model of turbulent convection from local sources of buoyancy and/or momentum acting for a short time has been developed and... 相似文献
8.
Ibotov Sh. Kh. Yuldasheva N. K. Mukarramov N. I. Zakirova R. P. Gusakova S. D. 《Chemistry of Natural Compounds》2022,58(4):728-731
Chemistry of Natural Compounds - 相似文献
9.
10.