全文获取类型
收费全文 | 297936篇 |
免费 | 3372篇 |
国内免费 | 847篇 |
专业分类
化学 | 162780篇 |
晶体学 | 4375篇 |
力学 | 12676篇 |
综合类 | 9篇 |
数学 | 34874篇 |
物理学 | 87441篇 |
出版年
2020年 | 2546篇 |
2019年 | 2740篇 |
2018年 | 3475篇 |
2017年 | 3462篇 |
2016年 | 5260篇 |
2015年 | 3350篇 |
2014年 | 5046篇 |
2013年 | 12333篇 |
2012年 | 9805篇 |
2011年 | 12073篇 |
2010年 | 8153篇 |
2009年 | 7833篇 |
2008年 | 11166篇 |
2007年 | 11376篇 |
2006年 | 10712篇 |
2005年 | 9805篇 |
2004年 | 8896篇 |
2003年 | 8011篇 |
2002年 | 7848篇 |
2001年 | 7722篇 |
2000年 | 6036篇 |
1999年 | 4693篇 |
1998年 | 4186篇 |
1997年 | 4172篇 |
1996年 | 4035篇 |
1995年 | 3662篇 |
1994年 | 3789篇 |
1993年 | 3455篇 |
1992年 | 3917篇 |
1991年 | 3902篇 |
1990年 | 3803篇 |
1989年 | 3662篇 |
1988年 | 3783篇 |
1987年 | 3653篇 |
1986年 | 3464篇 |
1985年 | 4704篇 |
1984年 | 4960篇 |
1983年 | 4103篇 |
1982年 | 4302篇 |
1981年 | 4232篇 |
1980年 | 4187篇 |
1979年 | 4148篇 |
1978年 | 4432篇 |
1977年 | 4329篇 |
1976年 | 4370篇 |
1975年 | 4052篇 |
1974年 | 4087篇 |
1973年 | 4243篇 |
1972年 | 2938篇 |
1971年 | 2452篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
21.
Kopytov G. F. Malyshko V. V. Goryachko A. I. Sharafan M. V. Churkina A. V. Moiseev A. V. Shashkov D. I. Lyasota O. M. 《Russian Physics Journal》2021,64(2):255-260
Russian Physics Journal - The specific features of the sorption activity of silver nanoparticles (AgNPs) on biodegradable polymers of natural (collagen) and artificial (polyamide 6.6) origin have... 相似文献
22.
Clemens G. Raab Georg Regensburger Jamal Hossein Poor 《Journal of Pure and Applied Algebra》2021,225(5):106564
A formal computation proving a new operator identity from known ones is, in principle, restricted by domains and codomains of linear operators involved, since not any two operators can be added or composed. Algebraically, identities can be modelled by noncommutative polynomials and such a formal computation proves that the polynomial corresponding to the new identity lies in the ideal generated by the polynomials corresponding to the known identities. In order to prove an operator identity, however, just proving membership of the polynomial in the ideal is not enough, since the ring of noncommutative polynomials ignores domains and codomains. We show that it suffices to additionally verify compatibility of this polynomial and of the generators of the ideal with the labelled quiver that encodes which polynomials can be realized as linear operators. Then, for every consistent representation of such a quiver in a linear category, there exists a computation in the category that proves the corresponding instance of the identity. Moreover, by assigning the same label to several edges of the quiver, the algebraic framework developed allows to model different versions of an operator by the same indeterminate in the noncommutative polynomials. 相似文献
23.
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
24.
Kielas-Jensen Calvin Cichella Venanzio Casbeer David Manyam Satyanarayana Gupta Weintraub Isaac 《Journal of Optimization Theory and Applications》2021,191(2-3):899-916
Journal of Optimization Theory and Applications - A framework for monitoring a target modeled as Dubins car using multiple UAVs is proposed. The UAVs are subject to minimum and maximum speed,... 相似文献
25.
26.
27.
28.
Smirnova T. D. Zhelobitskaya E. A. Danilina T. G. 《Journal of Analytical Chemistry》2022,77(8):1000-1004
Journal of Analytical Chemistry - Silver nanoparticles modified with Eu3+ ions increase the intensity of the fluorescence signal by a factor of 125 in an analytical system containing doxycycline as... 相似文献
29.
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
30.
Dzhun I. O. Babaitsev G. V. Kozin M. G. Romashkina I. L. Shanova E. I. Chechenin N. G. 《Physics of the Solid State》2021,63(6):825-831
Physics of the Solid State - The external factors which influence the ferromagnetic resonance (FMR) line width in bilayer (ferromagnet/antiferromagnet) exchange-biased systems are studied. The... 相似文献