全文获取类型
收费全文 | 1325篇 |
免费 | 65篇 |
国内免费 | 104篇 |
专业分类
化学 | 182篇 |
力学 | 81篇 |
综合类 | 9篇 |
数学 | 814篇 |
物理学 | 205篇 |
综合类 | 203篇 |
出版年
2023年 | 13篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 20篇 |
2019年 | 31篇 |
2018年 | 33篇 |
2017年 | 40篇 |
2016年 | 34篇 |
2015年 | 29篇 |
2014年 | 45篇 |
2013年 | 98篇 |
2012年 | 44篇 |
2011年 | 54篇 |
2010年 | 59篇 |
2009年 | 63篇 |
2008年 | 91篇 |
2007年 | 86篇 |
2006年 | 81篇 |
2005年 | 78篇 |
2004年 | 60篇 |
2003年 | 58篇 |
2002年 | 67篇 |
2001年 | 50篇 |
2000年 | 46篇 |
1999年 | 45篇 |
1998年 | 25篇 |
1997年 | 36篇 |
1996年 | 15篇 |
1995年 | 19篇 |
1994年 | 25篇 |
1993年 | 15篇 |
1992年 | 19篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1969年 | 3篇 |
排序方式: 共有1494条查询结果,搜索用时 31 毫秒
1.
This work is concerned with the extension of the Jacobi spectral Galerkin method to a class of nonlinear fractional pantograph differential equations. First, the fractional differential equation is converted to a nonlinear Volterra integral equation with weakly singular kernel. Second, we analyze the existence and uniqueness of solutions for the obtained integral equation. Then, the Galerkin method is used for solving the equivalent integral equation. The error estimates for the proposed method are also investigated. Finally, illustrative examples are presented to confirm our theoretical analysis. 相似文献
2.
Regis Guyonnet 《Journal of statistical physics》1991,65(1-2):269-289
The NMR properties of nuclei linked to long linear polymer molecules are sensitive to the influence of hard walls. In this context, the residual energy of tensorial spin-spin interactions is calculated using a path integral approach. Several thermodynamic quantities of the polymer system (free energy, equation of state,...) are also expressed, taking chain stiffness effects and the presence of two repulsive walls into consideration. 相似文献
3.
Based on the vectorial Rayleigh–Sommerfeld diffraction integrals, analytical expressions for the transversal and axial field distribution of plane waves propagating through a thin lens followed by a small circular aperture are derived and used to study the focusing and diffraction properties of plane waves. Some special cases of our general result are discussed, and illustrative numerical calculation results are given. It is found that the vectorial nonparaxial approach should be applied if the aperture dimension is comparable with the wavelength or the focusing is strong. 相似文献
4.
A Dirac picture perturbation theory is developed for the time evolution operator in classical dynamics in the spirit of the Schwinger–Feynman–Dyson perturbation expansion and detailed rules are derived for computations. Complexification formalisms are given for the time evolution operator suitable for phase space analyses, and then extended to a two-dimensional setting for a study of the geometrical Berry phase as an example. Finally a direct integration of Hamilton's equations is shown to lead naturally to a path integral expression, as a resolution of the identity, as applied to arbitrary functions of generalized coordinates and momenta. 相似文献
5.
集值Lebesgue—Stieltjes积分 总被引:8,自引:2,他引:6
本文首先刻划了B(R_ )上的集值测度,其次建立了(R_ B(R_ ))上的集值Lebesgue-Stieltjes积分.最后,进—步建立了集值随机Lebesgue-Stietjes积分的理论. 相似文献
6.
设F(p,q)和G(p,q)在无穷远点的邻域内是分别关于p和q的近似凸函数,且具有二次增长.考虑由F和G构成的一对定义在Soblev空间中的泛函.本文利用blowup技巧,证明了这样一对泛函的Nash平衡点实际上是Lipschitz连续的. 相似文献
7.
8.
In this work two non-local problems for the parabolic-hyperbolic type equation with non-characteristic line of changing type
are considered. Unique solvability of these problems is proven. The uniqueness of the solution is proven by the method of
energy integrals and the existence is proven by the method of integral equations. 相似文献
9.
José L. Ló pez Nico M. Temme 《Transactions of the American Mathematical Society》2004,356(11):4323-4342
Taylor expansions of analytic functions are considered with respect to several points, allowing confluence of any of them. Cauchy-type formulas are given for coefficients and remainders in the expansions, and the regions of convergence are indicated. It is explained how these expansions can be used in deriving uniform asymptotic expansions of integrals. The method is also used for obtaining Laurent expansions in several points as well as Taylor-Laurent expansions.
10.
Y. Brihaye S. Giller C. Gonera P. Kosinski P. Maslanka 《Czechoslovak Journal of Physics》2004,54(11):1185-1190
The dynamical systems of identical particles admitting quadratic integrals of motion are classified. The relevant integrals are explicitly constructed and their relation to separation of variables in Hamilton-Jacobi equation is clarified. 相似文献