全文获取类型
收费全文 | 94537篇 |
免费 | 2550篇 |
国内免费 | 145篇 |
专业分类
化学 | 55862篇 |
晶体学 | 467篇 |
力学 | 1779篇 |
综合类 | 3篇 |
数学 | 17026篇 |
物理学 | 22095篇 |
出版年
2022年 | 697篇 |
2021年 | 1030篇 |
2020年 | 1316篇 |
2019年 | 1137篇 |
2018年 | 1848篇 |
2017年 | 1569篇 |
2016年 | 2897篇 |
2015年 | 2405篇 |
2014年 | 2536篇 |
2013年 | 5450篇 |
2012年 | 4907篇 |
2011年 | 5172篇 |
2010年 | 3172篇 |
2009年 | 2735篇 |
2008年 | 4703篇 |
2007年 | 4503篇 |
2006年 | 4046篇 |
2005年 | 3842篇 |
2004年 | 3212篇 |
2003年 | 2727篇 |
2002年 | 2448篇 |
2001年 | 1923篇 |
2000年 | 1864篇 |
1999年 | 1326篇 |
1998年 | 1081篇 |
1997年 | 1025篇 |
1996年 | 1235篇 |
1995年 | 991篇 |
1994年 | 1104篇 |
1993年 | 1098篇 |
1992年 | 1019篇 |
1991年 | 831篇 |
1990年 | 896篇 |
1989年 | 762篇 |
1988年 | 749篇 |
1987年 | 689篇 |
1986年 | 663篇 |
1985年 | 980篇 |
1984年 | 940篇 |
1983年 | 793篇 |
1982年 | 837篇 |
1981年 | 843篇 |
1980年 | 731篇 |
1979年 | 679篇 |
1978年 | 730篇 |
1977年 | 687篇 |
1976年 | 672篇 |
1975年 | 599篇 |
1974年 | 587篇 |
1973年 | 602篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
In this paper a new multidimensional extension of the recently developed one-dimensional enclosure method called kite is given for interval global optimization. A more sophisticated version of the pruning technique based on the kite method is introduced. By the new componentwise approach all the one-dimensional theoretical results and procedures can be used in the higher-dimensional case. The possibilities in the implementation of the new algorithm together with numerical results on 40 standard test problems are presented. 相似文献
83.
Sylvia Pulmannová 《International Journal of Theoretical Physics》2004,43(7-8):1573-1585
Divisible effect algebras and their relations to convex effect algebras and MV-algebras are studied. A categorical equivalence between divisible effect algebras and rational vector spaces is proved. Infinitesimal, sharp and extremal elements in divisible effect algebras are studied and their relations to properties of the state space are shown. 相似文献
84.
Gábor Házi 《Central European Journal of Physics》2003,1(3):453-462
A general class of analytical solutions of the lattice Boltzmann equation is derived for two-dimensional, steady-state unidirectional
flows. A subset of the solutions that verifies the corresponding Navier-Stokes equations is given. It is pointed out that
this class includes, e.g., the Couette and the Poiseuille flow but not, e.g., the basic Kolmogorov flow. For steady-state
non-unidirectional flows, first and second order solutions of the lattice Boltzmann equation are derived. Practical consequences of the analysis
are mentioned. Differences between the technique applied here and those used in some earlier works are emphasized. 相似文献
85.
86.
In the present paper, Daubechies' wavelets and the computation of their scaling coefficients are briefly reviewed. Then a new method of computation is proposed. This method is based on the work [7] concerning a new orthonormality condition and relations among scaling moments, respectively. For filter lengths up to 16, the arising system can be explicitly solved with algebraic methods like Gröbner bases. Its simple structure allows one to find quickly all possible solutions. 相似文献
87.
Anna Jenčová 《International Journal of Theoretical Physics》2004,43(7-8):1635-1649
We use a class of generalized relative entropies on density matrices to obtain one-parameter families of torsion-free affine connections. 相似文献
88.
Z. Kassai V. Koprda K. Bauerová M. Harangozó P. Bendová A. Bujnová A. Kassai 《Journal of Radioanalytical and Nuclear Chemistry》2003,258(3):669-672
The composition and the permeation properties of the skin are dependent on age. In the animal models for permation studies, age affects the mechanical as well as the permeation properties significantly. The time dependence of permeation of 147Pm3+ from aqueous solution was established by the animal skin model and the age dependence of promethium permeation through the skin was examined. The aim was to find the optimum rat skin age model for radionuclide permeation studies and to assess the relative importance of the main permeation pathways: transepidermal and transfollicular permeation. The skin from 5-day-old rats (5DR) was found to represent the optimum animal model to study transepidermal permeation of ions. The skin from 9-day-old rats (9DR) was selected to study transfollicular permeation of ions. Comparison of the permeated amounts of promethium through the skin without hairs (3 DR to 6 DR) and with hairs (7DR to 12DR) showed that the additional permation mode via follicles significantly contributed to the permeation rate and extent. 相似文献
89.
90.