全文获取类型
收费全文 | 1379184篇 |
免费 | 30573篇 |
国内免费 | 8482篇 |
专业分类
化学 | 695241篇 |
晶体学 | 20541篇 |
力学 | 75533篇 |
综合类 | 161篇 |
数学 | 245355篇 |
物理学 | 381408篇 |
出版年
2021年 | 13639篇 |
2020年 | 16112篇 |
2019年 | 16218篇 |
2018年 | 13693篇 |
2016年 | 28685篇 |
2015年 | 21227篇 |
2014年 | 30840篇 |
2013年 | 75181篇 |
2012年 | 40541篇 |
2011年 | 38930篇 |
2010年 | 38702篇 |
2009年 | 40818篇 |
2008年 | 37655篇 |
2007年 | 33734篇 |
2006年 | 38800篇 |
2005年 | 31910篇 |
2004年 | 32215篇 |
2003年 | 30036篇 |
2002年 | 30817篇 |
2001年 | 30058篇 |
2000年 | 25896篇 |
1999年 | 23029篇 |
1998年 | 21281篇 |
1997年 | 21246篇 |
1996年 | 21346篇 |
1995年 | 19374篇 |
1994年 | 18824篇 |
1993年 | 18390篇 |
1992年 | 18426篇 |
1991年 | 18684篇 |
1990年 | 17830篇 |
1989年 | 17812篇 |
1988年 | 17352篇 |
1987年 | 17328篇 |
1986年 | 16304篇 |
1985年 | 22735篇 |
1984年 | 23928篇 |
1983年 | 20067篇 |
1982年 | 21760篇 |
1981年 | 20936篇 |
1980年 | 20290篇 |
1979年 | 20512篇 |
1978年 | 21774篇 |
1977年 | 21376篇 |
1976年 | 21163篇 |
1975年 | 19805篇 |
1974年 | 19484篇 |
1973年 | 19955篇 |
1972年 | 14466篇 |
1967年 | 12622篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
M. Amar D. Andreucci R. Gianni C. Timofte 《Journal of Mathematical Analysis and Applications》2021,493(2):124533
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation. 相似文献
82.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
83.
84.
Zadeba E. A. Khokhlov S. S. Kokoulin R. P. Petrukhin A. A. Shulzhenko I. A. Yashin I. I. 《Physics of Atomic Nuclei》2022,85(1):86-91
Physics of Atomic Nuclei - The muon puzzle is an excess of muon bundles generated by primary cosmic rays (PCR) at energies above 10 $${}^{17}$$ eV compared to estimations that assume even a heavy... 相似文献
85.
Numerical Algorithms - In this paper, the block generalized product-type bi-conjugate gradient (GPBi-CG) method for solving large, sparse nonsymmetric linear systems of equations with multiple... 相似文献
86.
Mathematical Notes - 相似文献
87.
88.
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
89.
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
90.
Chromatographia - The present work deals with the optimization, validation and application of a versatile HPLC–DAD method for concurrent estimation of nine antimicrobials and proton pump... 相似文献