全文获取类型
收费全文 | 17822篇 |
免费 | 357篇 |
国内免费 | 427篇 |
专业分类
化学 | 2448篇 |
晶体学 | 82篇 |
力学 | 112篇 |
综合类 | 37篇 |
数学 | 13993篇 |
物理学 | 1934篇 |
出版年
2023年 | 39篇 |
2022年 | 90篇 |
2021年 | 69篇 |
2020年 | 97篇 |
2019年 | 375篇 |
2018年 | 393篇 |
2017年 | 230篇 |
2016年 | 182篇 |
2015年 | 221篇 |
2014年 | 447篇 |
2013年 | 1374篇 |
2012年 | 545篇 |
2011年 | 1259篇 |
2010年 | 980篇 |
2009年 | 1067篇 |
2008年 | 1311篇 |
2007年 | 1366篇 |
2006年 | 1019篇 |
2005年 | 681篇 |
2004年 | 559篇 |
2003年 | 499篇 |
2002年 | 404篇 |
2001年 | 378篇 |
2000年 | 357篇 |
1999年 | 402篇 |
1998年 | 347篇 |
1997年 | 285篇 |
1996年 | 366篇 |
1995年 | 433篇 |
1994年 | 405篇 |
1993年 | 314篇 |
1992年 | 294篇 |
1991年 | 213篇 |
1990年 | 189篇 |
1989年 | 152篇 |
1988年 | 96篇 |
1987年 | 94篇 |
1986年 | 91篇 |
1985年 | 147篇 |
1984年 | 120篇 |
1983年 | 71篇 |
1982年 | 113篇 |
1981年 | 105篇 |
1980年 | 90篇 |
1979年 | 60篇 |
1978年 | 91篇 |
1977年 | 65篇 |
1976年 | 49篇 |
1975年 | 27篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Joshua Maglione 《Journal of Pure and Applied Algebra》2021,225(3):106528
Like the lower central series of a nilpotent group, filters generalize the connection between nilpotent groups and graded Lie rings. However, unlike the case with the lower central series, the associated graded Lie ring may share few features with the original group: e.g. the associated Lie ring can be trivial or arbitrarily large. We determine properties of filters such that every isomorphism between groups is induced by an isomorphism between graded Lie rings. 相似文献
2.
3.
Functional Binding Surface of a β‐Hairpin VEGF Receptor Targeting Peptide Determined by NMR Spectroscopy in Living Cells 下载免费PDF全文
Dr. Donatella Diana Anna Russomanno Dr. Lucia De Rosa Dr. Rossella Di Stasi Dr. Domenica Capasso Dr. Sonia Di Gaetano Dr. Alessandra Romanelli Dr. Luigi Russo Dr. Luca D. D'Andrea Prof. Roberto Fattorusso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):91-95
In this study, the functional interaction of HPLW peptide with VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) was determined by using fast 15N‐edited NMR spectroscopic experiments. To this aim, 15N uniformly labelled HPLW has been added to Porcine Aortic Endothelial Cells. The acquisition of isotope‐edited NMR spectroscopic experiments, including 15N relaxation measurements, allowed a precise characterization of the in‐cell HPLW epitope recognized by VEGFR2. 相似文献
4.
Tomasz Przebinda 《Journal of Functional Analysis》2018,274(5):1284-1305
We relate the distribution characters and the wave front sets of unitary representation for real reductive dual pairs of type I in the stable range. 相似文献
5.
Roberto Aravire Ahmed Laghribi Manuel ORyan 《Journal of Pure and Applied Algebra》2019,223(1):439-457
Let F be a field of characteristic 2. In this paper we give a complete computation of the kernel of the homomorphism induced by scalar extension, where is a purely inseparable extension (of any degree), is the cokernel of the Artin–Schreier operator given by: , where is the space of absolute m-differential forms over F and d is the differential operator. Other related results are included. 相似文献
6.
Sameerah Jamal 《Journal of Differential Equations》2019,266(7):4018-4026
A manifold that contains small perturbations will induce a perturbed partial differential equation. The partial differential equation that we select is the Poisson equation – in order to explore the interplay between the geometry of the manifold and the perturbations. Specifically, we show how the problem of symmetry determination, for higher-order perturbations, can be elegantly expressed via geometric conditions. 相似文献
7.
Alessandro Morando Paola Trebeschi Tao Wang 《Journal of Differential Equations》2019,266(9):5397-5430
We show the short-time existence and nonlinear stability of vortex sheets for the nonisentropic compressible Euler equations in two spatial dimensions, based on the weakly linear stability result of Morando and Trebeschi (2008) [20]. The missing normal derivatives are compensated through the equations of the linearized vorticity and entropy when deriving higher-order energy estimates. The proof of the resolution for this nonlinear problem follows from certain a priori tame estimates on the effective linear problem in the usual Sobolev spaces and a suitable Nash–Moser iteration scheme. 相似文献
8.
In this paper, we propose a sufficient and necessary condition for the boundedness of all the solutions for the equation with the critical situation that on g and p, where , is periodic and is bounded. 相似文献
9.
R.C. Viscovini E.M. Telles A. Scalabrin D. Pereira 《Applied physics. B, Lasers and optics》1997,65(1):33-35
2 laser of wide tunability to pump 13CD3OD we could observe 10 new far infrared laser lines ranging from 109 μm to 472 μm. The lines were generated by pumping infrared
absorbing transitions of large offset appertaining to the C-O stretching Q-branch. All lines were characterised in wavelength,
polarisation, optimum pressure of operation and precise offset measurements.
Received: 17 September 1996/Revised version: 18 November 1996 相似文献
10.
Summary. Let be a square matrix dependent on parameters and , of which we choose as the eigenvalue parameter. Many computational problems are equivalent to finding a point such that has a multiple eigenvalue at . An incomplete decomposition of a matrix dependent on several parameters is proposed. Based on the developed theory two new algorithms are
presented for computing multiple eigenvalues of with geometric multiplicity . A third algorithm is designed for the computation of multiple eigenvalues with geometric multiplicity but which also appears to have local quadratic convergence to semi-simple eigenvalues. Convergence analyses of these methods
are given. Several numerical examples are presented which illustrate the behaviour and applications of our methods.
Received December 19, 1994 / Revised version received January 18, 1996 相似文献