全文获取类型
收费全文 | 630篇 |
免费 | 151篇 |
国内免费 | 25篇 |
专业分类
化学 | 6篇 |
力学 | 131篇 |
综合类 | 10篇 |
数学 | 420篇 |
物理学 | 239篇 |
出版年
2024年 | 11篇 |
2023年 | 19篇 |
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 62篇 |
2019年 | 37篇 |
2018年 | 39篇 |
2017年 | 34篇 |
2016年 | 28篇 |
2015年 | 24篇 |
2014年 | 38篇 |
2013年 | 63篇 |
2012年 | 38篇 |
2011年 | 33篇 |
2010年 | 32篇 |
2009年 | 34篇 |
2008年 | 34篇 |
2007年 | 36篇 |
2006年 | 20篇 |
2005年 | 29篇 |
2004年 | 16篇 |
2003年 | 16篇 |
2002年 | 23篇 |
2001年 | 15篇 |
2000年 | 14篇 |
1999年 | 18篇 |
1998年 | 7篇 |
1997年 | 13篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有806条查询结果,搜索用时 0 毫秒
61.
M. A. Soloviev 《Theoretical and Mathematical Physics》2006,147(2):660-669
We analyze functional analytic aspects of axiomatic formulations of nonlocal and noncommutative quantum field theories. In
particular, we completely clarify the relation between the asymptotic commutativity condition, which ensures the CPT symmetry
and the standard spin-statistics relation for nonlocal fields, and the regularity properties of the retarded Green’s functions
in momentum space that are required for constructing a scattering theory and deriving reduction formulas. This result is based
on a relevant Paley-Wiener-Schwartz-type theorem for analytic functionals. We also discuss the possibility of using analytic
test functions to extend the Wightman axioms to noncommutative field theory, where the causal structure with the light cone
is replaced with that with the light wedge. We explain some essential peculiarities of deriving the CPT and spin-statistics
theorems in this enlarged framework.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 147, No. 2, pp. 257–269, May, 2006. 相似文献
62.
R. Anguelov J.K. Djoko J.M.‐S. Lubuma 《Numerical Methods for Partial Differential Equations》2008,24(1):41-59
The Burgers' equation, a simplification of the Navier–Stokes equations, is one of the fundamental model equations in gas dynamics, hydrodynamics, and acoustics that illustrates the coupling between convection/advection and diffusion. The kinetic energy enjoys boundedness and monotone decreasing properties that are useful in the study of the asymptotic behavior of the solution. We construct a family of non‐standard finite difference schemes, which replicate the energy equality and the properties of the kinetic energy. Our approach is based on Mickens' rule [Nonstandard Finite Difference Models of Differential Equations, World Scientific, Singapore, 1994.] of nonlocal approximation of nonlinear terms. More precisely, we propose a systematic nonlocal way of generating approximations that ensure that the trilinear form is identically zero for repeated arguments. We provide numerical experiments that support the theory and demonstrate the power of the non‐standard schemes over the classical ones. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
63.
Nonlocal mathematical models appear in various problems of physics and engineering. In these models the integral term may appear in the boundary conditions. In this paper the problem of solving the one‐dimensional parabolic partial differential equation subject to given initial and nonlocal boundary conditions is considered. These kinds of problems have certainly been one of the fastest growing areas in various application fields. The presence of an integral term in a boundary condition can greatly complicate the application of standard numerical techniques. As a well‐known class of meshless methods, the radial basis functions are used for finding an approximation of the solution of the present problem. Numerical examples are given at the end of the paper to compare the efficiency of the radial basis functions with famous finite‐difference methods. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008 相似文献
64.
Bessel solitary wave solutions to a two-dimensional strongly nonlocal nonlinear Schrödinger equation with distributed coefficients are obtained. Bessel solitary wave solutions have unique characteristics compared with Gaussian solitary wave solutions, Laguerre-Gaussian solitary wave solutions, and Hermite-Gaussian solitary wave solutions. The generalized two-dimensional nonlocal nonlinear Schrödinger equation with distributed coefficients is investigated for the first time to our knowledge. 相似文献
65.
Defining nonlocality in a no-input closed quantum network scenario is a new area of interest nowadays. Gisin, in [Entropy 21, 325 (2019)], proposed a possible condition for non-tri-locality of the trivial no-input closed network scenario, triangle network, by introducing a new kind of joint measurement bases and a probability bound. In [npj Quantum Information (2020) 6:70] they found a shred of numerical evidence in support of Gisin's probability bound. Now based on that probability bound, it finds the nature of the correlation in a triangle network scenario. This study observes how far the probability lies from that Gisin's bound with every possible combination of entangled and local pure states distributed from three independent quantum sources. Here, it uses the generalized Elegant Joint Measurements bases for each party and find that there is a dependency of non-locality on the entanglement of these joint measurement bases. It also checks the probability bound for the polygon structure. 相似文献
66.
Existence of ground state solutions for Kirchhoff‐type problems involving critical Sobolev exponents
《Mathematical Methods in the Applied Sciences》2018,41(1):371-385
In this paper, we study the existence of ground state solutions for a Kirchhoff‐type problem in involving critical Sobolev exponent. With the help of Nehari manifold and the concentration‐compactness principle, we prove that problem admits at least one ground state solution. 相似文献
67.
68.
Stability and Hopf bifurcation of a delayed predator-prey system with nonlocal competition and herd behaviour 下载免费PDF全文
In this paper, we investigate the stability and Hopf bifurcation of a diffusive predator-prey system with herd behaviour. The model is described by introducing both time delay and nonlocal prey intraspecific competition. Compared to the model without time delay, or without nonlocal competition, thanks to the together action of time delay and nonlocal competition, we prove that the first critical value of Hopf bifurcation may be homogenous or non-homogeneous. We also show that a double-Hopf bifurcation occurs at the intersection point of the homogenous and non-homogeneous Hopf bifurcation curves. Furthermore, by the computation of normal forms for the system near equilibria, we investigate the stability and direction of Hopf bifurcation. Numerical simulations also show that the spatially homogeneous and non-homogeneous periodic patters. 相似文献
69.
70.