全文获取类型
收费全文 | 7182篇 |
免费 | 158篇 |
国内免费 | 6篇 |
专业分类
化学 | 4205篇 |
晶体学 | 39篇 |
力学 | 163篇 |
综合类 | 1篇 |
数学 | 1512篇 |
物理学 | 1426篇 |
出版年
2022年 | 46篇 |
2021年 | 79篇 |
2020年 | 82篇 |
2019年 | 82篇 |
2018年 | 168篇 |
2017年 | 155篇 |
2016年 | 237篇 |
2015年 | 176篇 |
2014年 | 235篇 |
2013年 | 551篇 |
2012年 | 375篇 |
2011年 | 478篇 |
2010年 | 275篇 |
2009年 | 234篇 |
2008年 | 412篇 |
2007年 | 408篇 |
2006年 | 369篇 |
2005年 | 291篇 |
2004年 | 250篇 |
2003年 | 176篇 |
2002年 | 175篇 |
2001年 | 119篇 |
2000年 | 90篇 |
1999年 | 68篇 |
1998年 | 57篇 |
1997年 | 60篇 |
1996年 | 56篇 |
1995年 | 62篇 |
1994年 | 40篇 |
1993年 | 60篇 |
1992年 | 67篇 |
1991年 | 49篇 |
1990年 | 55篇 |
1989年 | 59篇 |
1988年 | 56篇 |
1987年 | 57篇 |
1986年 | 42篇 |
1985年 | 63篇 |
1984年 | 69篇 |
1983年 | 72篇 |
1982年 | 72篇 |
1981年 | 48篇 |
1980年 | 60篇 |
1979年 | 51篇 |
1978年 | 75篇 |
1977年 | 43篇 |
1976年 | 59篇 |
1975年 | 45篇 |
1974年 | 55篇 |
1973年 | 43篇 |
排序方式: 共有7346条查询结果,搜索用时 10 毫秒
1.
2.
Periodica Mathematica Hungarica - We present a tight parametrical Hermite–Hadamard type inequality with probability measure, which yields a considerably closer upper bound for the mean value... 相似文献
3.
4.
5.
N. S. Simonović 《Few-Body Systems》2006,38(2-4):139-145
In agreement with the Kohn theorem the relative motion (rel) of three electrons in a two-dimensional parabolic trap separates
from the centre-of-mass (CM) motion. By introducing new coordinates the Hamiltonian for relative motion in the approximation
of non-interacting electrons can be taken to the normal form. The eigenstates of the normalized Hamiltonian are products of
the Fock-Darwin states for normal modes. The energy levels for relative motion are obtained by diagonalizing the exact Hamiltonian
in the eigenbasis for the non-interacting case. In this basis the interaction matrix elements can be obtained in the analytical
form. Since the rank of the Hamiltonian matrix is significantly reduced, the calculations are faster and more accurate than
those for the full (CM + rel) motion. This advantage is especially important for the calculations of excited states and the
analysis of energy spectra. 相似文献
6.
Milan Medved? 《Journal of Mathematical Analysis and Applications》2002,267(2):643-650
A criterion for the nonexplosion of solutions to semilinear evolution equations on Banach spaces is proved. The result is obtained by applying a modification of the Bihari type inequality to the case of a weakly singular nonlinear integral inequality. 相似文献
7.
8.
9.
Milan V. Patel Samir A. Patel Arabinda Ray Rajni M. Patel 《Journal of polymer science. Part A, Polymer chemistry》2004,42(20):5227-5234
Copolymers of monomers 2,4‐dichlorophenyl methacrylate (2,4‐DMA) and methyl methacrylate (MMA) were synthesized with different monomer feed ratios using toluene as a solvent and 2,2′‐azobisisobutyronitrile (AIBN) as an initiator at 70 °C. The copolymers were characterized by IR‐spectroscopy, and copolymer composition was determined with UV‐spectroscopy. The linearization method of Fineman–Ross was employed to obtain the monomer reactivity ratios. The molecular weights and polydispersity indexes were determined by gel permeation chromatography (GPC). Thermogravimetric analyses of polymers were carried out in nitrogen atmosphere. The homo‐ and copolymers were tested for their antimicrobial properties against selected microorganisms. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5227–5234, 2004 相似文献
10.
The new techniques and ideas in quantum interferometry with neutrons, photons, atoms, electrons, and Bose condensates that fluorished in the last two decades have influenced in a decisive way the thinking and the research in the foundations and interpretation of quantum mechanics. The controversies existing among different schools on the reality of matter waves of quantum theory, the postulates of quantum measurement theory, and the (in)completeness of quantum mechanics have to be approached now in a new way. Our argumentation follows the spirit of the Paris school. 相似文献