全文获取类型
收费全文 | 6572篇 |
免费 | 146篇 |
国内免费 | 4篇 |
专业分类
化学 | 3802篇 |
晶体学 | 37篇 |
力学 | 128篇 |
数学 | 1417篇 |
物理学 | 1338篇 |
出版年
2022年 | 73篇 |
2021年 | 127篇 |
2020年 | 76篇 |
2019年 | 75篇 |
2018年 | 163篇 |
2017年 | 151篇 |
2016年 | 228篇 |
2015年 | 166篇 |
2014年 | 224篇 |
2013年 | 530篇 |
2012年 | 331篇 |
2011年 | 457篇 |
2010年 | 240篇 |
2009年 | 217篇 |
2008年 | 373篇 |
2007年 | 356篇 |
2006年 | 333篇 |
2005年 | 247篇 |
2004年 | 215篇 |
2003年 | 146篇 |
2002年 | 139篇 |
2001年 | 98篇 |
2000年 | 82篇 |
1999年 | 59篇 |
1998年 | 50篇 |
1997年 | 49篇 |
1996年 | 50篇 |
1995年 | 48篇 |
1993年 | 42篇 |
1992年 | 54篇 |
1991年 | 48篇 |
1990年 | 48篇 |
1989年 | 52篇 |
1988年 | 47篇 |
1987年 | 47篇 |
1986年 | 41篇 |
1985年 | 61篇 |
1984年 | 68篇 |
1983年 | 64篇 |
1982年 | 64篇 |
1981年 | 44篇 |
1980年 | 53篇 |
1979年 | 47篇 |
1978年 | 70篇 |
1977年 | 41篇 |
1976年 | 54篇 |
1975年 | 41篇 |
1974年 | 49篇 |
1973年 | 41篇 |
1972年 | 33篇 |
排序方式: 共有6722条查询结果,搜索用时 979 毫秒
1.
2.
Rutkowski Paweł Klimczyk Piotr Jaworska Lucyna Stobierski Ludosław Dubiel Aleksandra 《Journal of Thermal Analysis and Calorimetry》2015,122(1):105-114
Journal of Thermal Analysis and Calorimetry - The work concerns the alumina–graphene materials sintered by two different pressure methods. The different particle sizes of graphene were used.... 相似文献
3.
4.
5.
Tanja Vidaković-Koch Tamara Miličić Luka A. Živković Hoon Seng Chan Ulrike Krewer Menka Petkovska 《Current Opinion in Electrochemistry》2021
The nonlinear frequency response analysis (NFRA) can be seen as an extension of electrochemical impedance spectroscopy. NFRA gives a full and detailed representation of the system response and can establish a connection between model parameters and the experimentally observed phenomena. In this article, different theoretical NFRA approaches and the most recent application examples are discussed. A simple electrochemical example is used to showcase the benefits and disadvantages of analyzing the system response by using different approaches. In addition, it was shown how to extract experimental harmonic values and analyze them. 相似文献
6.
7.
Boban Marinković 《Mathematical Methods of Operations Research》2006,63(3):513-524
We present local sensitivity analysis for discrete optimal control problems with varying endpoints in the case when the customary regularity of boundary conditions can be violated. We study the behavior of the optimal solutions subject to parametric perturbations of the problem. 相似文献
8.
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
9.
10.
Ching Sum Hui Lillian Sze Man Lam Chun Yin Wai Kin Chan Aleksandra B. Djurii 《Journal of polymer science. Part A, Polymer chemistry》2003,41(11):1708-1715
Polyurethanes incorporated with rhenium diimine complexes were synthesized. The polymers exhibited interesting morphologies and solution properties. Results from gel permeation chromatography suggested the formation of polymer aggregates in solutions. The polymers could act as probes for metal ions. The addition of metal ions to polymer solutions led to significant changes in the electronic absorption properties of the polymer solutions. This was attributed to the interactions between the polyether moieties and metal ions. The metal complexes could also act as efficient photosensitizers. After doping with charge‐transport viologens, the photoconductivity of the polymers was greatly enhanced. The experimental quantum efficiency was simulated with Onsager's theory. The thermalization distances and the primary yields were typically 12–14 Å and 10?3, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1708–1715, 2003 相似文献