全文获取类型
收费全文 | 3564篇 |
免费 | 310篇 |
国内免费 | 143篇 |
专业分类
化学 | 177篇 |
晶体学 | 1篇 |
力学 | 872篇 |
综合类 | 43篇 |
数学 | 2173篇 |
物理学 | 751篇 |
出版年
2024年 | 2篇 |
2023年 | 45篇 |
2022年 | 61篇 |
2021年 | 73篇 |
2020年 | 126篇 |
2019年 | 98篇 |
2018年 | 88篇 |
2017年 | 108篇 |
2016年 | 106篇 |
2015年 | 104篇 |
2014年 | 156篇 |
2013年 | 270篇 |
2012年 | 147篇 |
2011年 | 219篇 |
2010年 | 170篇 |
2009年 | 239篇 |
2008年 | 203篇 |
2007年 | 218篇 |
2006年 | 205篇 |
2005年 | 183篇 |
2004年 | 155篇 |
2003年 | 159篇 |
2002年 | 102篇 |
2001年 | 107篇 |
2000年 | 99篇 |
1999年 | 90篇 |
1998年 | 101篇 |
1997年 | 66篇 |
1996年 | 60篇 |
1995年 | 28篇 |
1994年 | 49篇 |
1993年 | 27篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1957年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有4017条查询结果,搜索用时 0 毫秒
261.
Yu. V. Vassilevski I. V. Kapyrin 《Computational Mathematics and Mathematical Physics》2008,48(8):1349-1366
Two splitting schemes are proposed for the numerical solution of three-dimensional nonstationary convection-diffusion problems on unstructured meshes in the case of a full diffusion tensor. An advantage of the first scheme is that splitting is generated by the properties of the approximation spaces and does not reduce the order of accuracy. An advantage of the second scheme is that the resulting numerical solutions are nonnegative. A numerical study is conducted to compare the splitting schemes with classical methods, such as finite elements and mixed finite elements. The numerical results show that the splitting schemes are characterized by low dissipation, high-order accuracy, and versatility. 相似文献
262.
Ajit Patel Amiya K. Pani Neela Nataraj 《Numerical Methods for Partial Differential Equations》2008,24(6):1460-1484
In this article a standard mortar finite element method and a mortar element method with Lagrange multiplier are used for spatial discretization of a class of parabolic initial‐boundary value problems. Optimal error estimates in L∞(L2) and L∞(H1)‐norms for semidiscrete methods for both the cases are established. The key feature that we have adopted here is to introduce a modified elliptic projection. In the standard mortar element method, a completely discrete scheme using backward Euler scheme is discussed and optimal error estimates are derived. The results of numerical experiments support the theoretical results obtained in this article. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008 相似文献
263.
In this paper, we use a semi-discrete and a padé approximation method to propose a new difference scheme for solving convection–diffusion problems. The truncation error of the difference scheme is O(h4+τ5). It is shown through analysis that the scheme is unconditionally stable. Numerical experiments are conducted to test its high accuracy and to compare it with Crank–Nicolson method. 相似文献
264.
In this paper, we present an extended ghost fluid method (GFM) for computations of inviscid compressible multifluids in Lagrangian coordinate. That is, we capture the appropriate interface conditions by defining a fluid that has the velocity and the pressure of the real fluid at each point, but the entropy or the internal energy of some other fluid. Meanwhile, a single-fluid solver, CWENO-type central-upwind scheme, is developed in Lagrangian coordinate. The high resolution and the non-oscillatory quality of the scheme can be verified by solving several numerical experiments. 相似文献
265.
Stéphane Labbé 《Journal of Mathematical Analysis and Applications》2009,356(2):477-497
This paper is devoted to the analysis of flux schemes coupled with the reservoir technique for approximating hyperbolic equations and linear hyperbolic systems of conservation laws [F. Alouges, F. De Vuyst, G. Le Coq, E. Lorin, The reservoir scheme for systems of conservation laws, in: Finite Volumes for Complex Applications, III, Porquerolles, 2002, Lab. Anal. Topol. Probab. CNRS, Marseille, 2002, pp. 247-254 (electronic); F. Alouges, F. De Vuyst, G. Le Coq, E. Lorin, Un procédé de réduction de la diffusion numérique des schémas à différence de flux d'ordre un pour les systèmes hyperboliques non linéaires, C. R. Math. Acad. Sci. Paris 335 (7) (2002) 627-632; F. Alouges, F. De Vuyst, G. Le Coq, E. Lorin, The reservoir technique: A way to make Godunov-type schemes zero or very low diffusive. Application to Colella-Glaz, Eur. J. Mech. B Fluids 27 (6) (2008)]. We prove the long time convergence of the reservoir technique and its TVD property for some specific but still general configurations. Proofs are based on a precise study of the treatment by the reservoir technique of shock and rarefaction waves. 相似文献
266.
在曲线的多分辨率分析基础上,构造了一种新的非线性三分多分辨率算法.并研究这个正则三分多分辨率算法的收敛性和稳定性,进一步,证明了小波参数的收敛性精密地依靠这个基本的多分辨率细分算法的收敛性. 相似文献
267.
Xicheng Zhang 《Journal of Differential Equations》2008,244(9):2226-2250
In this paper, an Euler type approximation is constructed for stochastic Volterra equation with singular kernels, which provides an algorithm for numerical calculation. Then, the large deviation estimates of small perturbation to equations of this type are obtained. We finally apply them to SDEs with the kernel of fractional Brownian motion with Hurst parameter H∈(0,1). 相似文献
268.
Henk J.A.M. Heijmans Batrice Pesquet-Popescu Gemma Piella 《Applied and Computational Harmonic Analysis》2005,18(3):252-281
In this paper, we propose a technique for building adaptive wavelets by means of an extension of the lifting scheme. Our scheme comprises an adaptive update lifting step and a fixed prediction lifting step. The adaptivity consists hereof that the system can choose between two different update filters, and that this choice is triggered by the local gradient of the original signal. If the gradient is large (in some seminorm sense) it chooses one filter, if it is small the other. We derive necessary and sufficient conditions for the invertibility of such an adaptive system for various scenarios. Furthermore, we present some examples to illustrate our theoretical results. 相似文献
269.
Convergence analysis of implicit iterative algorithms for asymptotically nonexpansive mappings 总被引:1,自引:0,他引:1
In this paper, we consider the weak and strong convergence of an implicit iterative process with errors for two finite families of asymptotically nonexpansive mappings in the framework of Banach spaces. Our results presented in this paper improve and extend the recent ones announced by many others. 相似文献
270.
Yousef Hashem Zahran 《国际流体数值方法杂志》2008,57(6):745-760
We describe a hybrid method for the solution of hyperbolic conservation laws. A third‐order total variation diminishing (TVD) finite difference scheme is conjugated with a random choice method (RCM) in a grid‐based adaptive way. An efficient multi‐resolution technique is used to detect the high gradient regions of the numerical solution in order to capture the shock with RCM while the smooth regions are computed with the more efficient TVD scheme. The hybrid scheme captures correctly the discontinuities of the solution and saves CPU time. Numerical experiments with one‐ and two‐dimensional problems are presented. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献