全文获取类型
收费全文 | 3481篇 |
免费 | 491篇 |
国内免费 | 276篇 |
专业分类
化学 | 207篇 |
晶体学 | 4篇 |
力学 | 290篇 |
综合类 | 78篇 |
数学 | 3352篇 |
物理学 | 317篇 |
出版年
2024年 | 9篇 |
2023年 | 37篇 |
2022年 | 27篇 |
2021年 | 63篇 |
2020年 | 101篇 |
2019年 | 96篇 |
2018年 | 121篇 |
2017年 | 158篇 |
2016年 | 150篇 |
2015年 | 97篇 |
2014年 | 129篇 |
2013年 | 291篇 |
2012年 | 163篇 |
2011年 | 184篇 |
2010年 | 145篇 |
2009年 | 160篇 |
2008年 | 180篇 |
2007年 | 227篇 |
2006年 | 217篇 |
2005年 | 194篇 |
2004年 | 158篇 |
2003年 | 171篇 |
2002年 | 169篇 |
2001年 | 157篇 |
2000年 | 126篇 |
1999年 | 117篇 |
1998年 | 93篇 |
1997年 | 91篇 |
1996年 | 61篇 |
1995年 | 66篇 |
1994年 | 48篇 |
1993年 | 39篇 |
1992年 | 37篇 |
1991年 | 28篇 |
1990年 | 19篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 16篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1957年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有4248条查询结果,搜索用时 62 毫秒
101.
Piotr Kacprzyk 《Mathematical Methods in the Applied Sciences》2013,36(3):313-322
Global existence of regular solutions to the Navier–Stokes equations coupled with the heat convection in a cylindrical pipe has already been shown. In this paper, we prove the existence of the global attractor to the equations and convergence of their solutions to a stationary one. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
102.
Jörg Steinbach 《Numerical Functional Analysis & Optimization》2013,34(3-4):395-411
The mathematical model of the injection molding process is characterized by evolutionary inequalities with an elliptic principal part and a Volterra term. Existence and uniqueness of the solution of these problems are derived by means of an argument based on the Banach fixed point theorem. Regularity results are obtained by using the penalty and Rothe method. The results can be considered as a starting point for the numerical treatment and for the application to injection molding. 相似文献
103.
《Optimization》2012,61(7):857-878
In this article, by means of an active set and limited memory strategy, we propose a trust-region method for box-constrained nonsmooth equations. The global convergence and the superlinear convergence are established under suitable conditions. 相似文献
104.
B. A. Strukov 《Phase Transitions》2013,86(2-3):143-179
A review of the basic experimental results connected with the formation of long-living metastable states in the incommensurate phases of ferroelectric crystals and related phenomena is given. The interpretation and appropriate physical mechanisms underlying the global hysteresis phenomena associated with these states are considered. 相似文献
105.
《Optimization》2012,61(11):2277-2287
Two adaptive choices for the parameter of Dai–Liao conjugate gradient (CG) method are suggested. One of which is obtained by minimizing the distance between search directions of Dai–Liao method and a three-term CG method proposed by Zhang et al. and the other one is obtained by minimizing Frobenius condition number of the search direction matrix. Global convergence analyses are made briefly. Numerical results are reported; they demonstrate effectiveness of the suggested adaptive choices. 相似文献
106.
《Physics letters. A》2014,378(38-39):2831-2844
A new global stochastic search, guided mainly through derivative-free directional information computable from the sample statistical moments of the design variables within a Monte Carlo setup, is proposed. The search is aided by imparting to the directional update term additional layers of random perturbations referred to as ‘coalescence’ and ‘scrambling’. A selection step, constituting yet another avenue for random perturbation, completes the global search. The direction-driven nature of the search is manifest in the local extremization and coalescence components, which are posed as martingale problems that yield gain-like update terms upon discretization. As anticipated and numerically demonstrated, to a limited extent, against the problem of parameter recovery given the chaotic response histories of a couple of nonlinear oscillators, the proposed method appears to offer a more rational, more accurate and faster alternative to most available evolutionary schemes, prominently the particle swarm optimization. 相似文献
107.
In this paper, we establish new sufficient conditions for the infected equilibrium of a nonresident computer virus model to be globally asymptotically stable. Our results extend two kind of known results in recent literature. 相似文献
108.
媒体报道对传染病的传播有着一定的影响,但它并不是影响其传播的本质因素.通过建立一个具有分段感染率的传染病模型来刻画媒体报道对传染病传播影响的饱和性.分析了系统各平衡态的局部稳定性,同时利用排除极限环的存在性证明了各平衡态的全局稳定性.最后,通过模拟来验证我们的理论分析. 相似文献
109.
Caterina Calgaro Claire Colin Emmanuel Creus Ezzeddine Zahrouni 《Mathematical Methods in the Applied Sciences》2019,42(1):250-271
In this work, we prove the existence and the uniqueness of the strong solution of a low‐Mach model, for which the dynamic viscosity of the fluid is a given function of its temperature. The method is based on the convergence study of a sequence towards the solution, for which the rates are also given. The originality of the approach is to consider the system in terms of the temperature and the velocity, leading to a nonlinear temperature equation and the development of some specific tools and results. 相似文献
110.
The purpose of this research is to present a novel scheme based on a quick iterative scheme for calculating the matrix geometric mean of two Hermitian positive definite (HPD) matrices. To do this, an iterative scheme with global convergence is constructed for the sign function using a novel three‐step root‐solver. It is proved that the new scheme is convergent and shown to have global convergence behavior for this target, when square matrices having no pure imaginary eigenvalues. Next, the constructed scheme is used and extended through a well‐known identity for the calculation of the matrix geometric mean of two HPD matrices. Ultimately, several experiments are collected to show its usefulness. 相似文献