全文获取类型
收费全文 | 6708篇 |
免费 | 325篇 |
国内免费 | 68篇 |
专业分类
化学 | 4598篇 |
晶体学 | 66篇 |
力学 | 269篇 |
综合类 | 5篇 |
数学 | 740篇 |
物理学 | 1423篇 |
出版年
2024年 | 39篇 |
2023年 | 81篇 |
2022年 | 278篇 |
2021年 | 437篇 |
2020年 | 297篇 |
2019年 | 279篇 |
2018年 | 287篇 |
2017年 | 236篇 |
2016年 | 332篇 |
2015年 | 262篇 |
2014年 | 289篇 |
2013年 | 531篇 |
2012年 | 441篇 |
2011年 | 488篇 |
2010年 | 294篇 |
2009年 | 263篇 |
2008年 | 271篇 |
2007年 | 282篇 |
2006年 | 198篇 |
2005年 | 183篇 |
2004年 | 118篇 |
2003年 | 114篇 |
2002年 | 100篇 |
2001年 | 87篇 |
2000年 | 63篇 |
1999年 | 64篇 |
1998年 | 36篇 |
1997年 | 31篇 |
1996年 | 51篇 |
1995年 | 47篇 |
1994年 | 29篇 |
1993年 | 37篇 |
1992年 | 36篇 |
1991年 | 44篇 |
1990年 | 20篇 |
1989年 | 27篇 |
1988年 | 33篇 |
1987年 | 30篇 |
1986年 | 30篇 |
1985年 | 41篇 |
1984年 | 26篇 |
1983年 | 25篇 |
1982年 | 24篇 |
1981年 | 14篇 |
1980年 | 28篇 |
1979年 | 23篇 |
1978年 | 28篇 |
1977年 | 28篇 |
1976年 | 21篇 |
1973年 | 12篇 |
排序方式: 共有7101条查询结果,搜索用时 46 毫秒
971.
Abdulaziz K. Alsharidi Ashfaq A. Khan John J. Shepherd Andrew J. Stacey 《Mathematical Methods in the Applied Sciences》2020,43(9):5729-5743
We construct the slowly varying limiting state solutions to a nonlinear dynamical system for anaerobic digestion with Monod-based kinetics involving slowly varying model parameters arising from slow environmental variation. The advantage of these approximate solutions over numerical solutions is their applicability to a wide range of parameter values. We use these limiting state solutions to develop analytic approximations to the full nonlinear system by applying a multiscaling technique. The approximate solutions are shown to compare favorably with numerical solutions. 相似文献
972.
Jawali C. Umavathi Hafiz Muhammad Ali Sapnali Limbaraj Patil 《Mathematical Methods in the Applied Sciences》2020,43(15):9223-9244
The motivation of the current article is to explore a numerical investigation on steady triply diffusive convection in a vertical channel. Heat is exchanged from the external fluid with the plates. The reference temperature is taken as equal and also as different for the external fluid. Solutions in the absence of viscous dissipation and buoyancy forces are also obtained as special cases. General solutions including the effects of viscous dissipation and buoyancy forces are obtained analytically using the method of perturbation. The analytical solutions can be used only if the Brinkman number is small. Hence to know the flow properties for all values of Brinkman number, we resort to numerical solutions. The effects of thermal Grashof number, solutal Grashof number, and the chemical reaction parameter on the flow field are evaluated numerically. The obtained results are validated against previously published results for special case of the problems. 相似文献
973.
Gabriel J. H. Khan 《Annals of Global Analysis and Geometry》2018,53(2):233-249
We consider \(\lambda \) is the principle eigenvalue of the complex Laplacian on a compact Hermitian manifold M. We prove that \(\lambda \ge C\) where C depends only on the dimension n, the diameter d, the Ricci curvature of the Levi-Civita connection on M, and a norm, expressed in curvature, that determines how much M fails to be Kähler. We first estimate the principal eigenvalue of a drift Laplacian and then study the structure of Hermitian manifolds using recent results due to Yang and Zheng (on curvature tensors of Hermitian manifolds, 2016. arXiv:1602.01189). We combine these results to obtain the main estimate. We also discuss several special cases in which one can obtain a lower bound solely in terms of the Riemannian geometry. 相似文献
974.
In this paper, we compute depth and Stanley depth for the quotient ring of the edge ideal associated to a square path on n vertices. We also compute depth and Stanley depth for the quotient ring of the edge ideal associated to a square cycle on n vertices, when n≡0,3,4( mod 5), and give tight bounds when n≡1,2( mod 5). We also prove a conjecture of Herzog presented in [5], for the edge ideals of square paths and square cycles. 相似文献
975.
A new third order exponentially fitted discretization for the solution of non-linear two point boundary value problems on a graded mesh
下载免费PDF全文
![点击此处可从《Journal of Applied Analysis & Computation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R. K. Mohanty Geetan Manchand Gunjan Khuran Arshad Khan 《Journal of Applied Analysis & Computation》2020,10(5):1741-1770
This paper puts forward a novel graded mesh implicit scheme resting upon full step discretization of order three for computation of non-linear two point boundary value problems. The suggested method is compact and employs three nodal points for the unknown function $u(x)$ in spatial axis. We have also performed error analysis of the cited method. The given method was tried (implemented) upon multiple problems in Cartesian and Polar coordinates with extremely favorable outcomes. This method, though meant for scalar equations, was further extended to compute the vector equations of two point nonlinear boundary value problems. To check the validity of the proposed scheme, we applied it to multiple problems and obtained supporting numerical computations. 相似文献
976.
In this short note, our aim is to investigate the inverse problem of parameter identification in quasi-variational inequalities. We develop an abstract nonsmooth regularization approach that subsumes the total variation regularization and permits the identification of discontinuous parameters. We study the inverse problem in an optimization setting using the output-least squares formulation. We prove the existence of a global minimizer and give convergence results for the considered optimization problem. We also discretize the identification problem for quasi-variational inequalities and provide the convergence analysis for the discrete problem. We give an application to the gradient obstacle problem. 相似文献
977.
Muhammad Akram Saba Siddique Bijan Davvaz 《Journal of Applied Mathematics and Computing》2018,57(1-2):279-302
A neutrosophic set is a generalization of an intuitionistic fuzzy set. Neutrosophic models give more flexibility, precisions and compatibility to the system as compared to intuitionistic fuzzy models. In this research study, we apply the concept of neutrosophic sets to graphs and discuss certain concepts of single-valued neutrosophic graphs. We illustrate the concepts by several examples. We investigate some interesting properties. We describe an application of single-valued neutrosophic graph in decision making process. We also present the procedure of our proposed method as an algorithm. 相似文献
978.
Zhang introduced the concept of bipolar fuzzy sets as a generalization of fuzzy sets. Bipolar fuzzy sets have shown advantages in solving decision making problems than fuzzy sets. In this research paper, we study several different types of domination, including equitable domination, k-domination and restrained domination in bipolar fuzzy graphs. We present novel applications of bipolar fuzzy graphs to decision making problems. We also present an algorithm for computing dominating number in our applications. 相似文献
979.
Godwin Chidi Ugwunnadi Abdul Rahim Khan Mujahid Abbas 《Journal of Fixed Point Theory and Applications》2018,20(2):82
We introduce a hybrid proximal point algorithm and establish its strong convergence to a common solution of a proximal point of a lower semi-continuous mapping and a fixed point of a demicontractive mapping in the framework of a CAT(0) space. As applications of our new result, we solve variational inequality problems for these mappings on a Hilbert space. Illustrative example is given to validate theoretical result obtained herein. 相似文献
980.
The objective of this note is to provide some(potentially useful) integral transforms(for example, Euler, Laplace, Whittaker etc.) associated with the generalized k-Bessel function defined by Saiful and Nisar [3]. We have also discussed some other transforms as special cases of our main results. 相似文献