全文获取类型
收费全文 | 583篇 |
免费 | 98篇 |
国内免费 | 44篇 |
专业分类
化学 | 135篇 |
晶体学 | 1篇 |
力学 | 39篇 |
综合类 | 13篇 |
数学 | 433篇 |
物理学 | 104篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 23篇 |
2018年 | 22篇 |
2017年 | 37篇 |
2016年 | 29篇 |
2015年 | 26篇 |
2014年 | 29篇 |
2013年 | 67篇 |
2012年 | 26篇 |
2011年 | 41篇 |
2010年 | 28篇 |
2009年 | 36篇 |
2008年 | 35篇 |
2007年 | 33篇 |
2006年 | 34篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 21篇 |
2002年 | 28篇 |
2001年 | 28篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 8篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有725条查询结果,搜索用时 17 毫秒
1.
Blow‐up phenomena for a semilinear parabolic equation with weighted inner absorption under nonlinear boundary flux 下载免费PDF全文
Blow‐up phenomena for a nonlinear divergence form parabolic equation with weighted inner absorption term are investigated under nonlinear boundary flux in a bounded star‐shaped region. We assume some conditions on weight function and nonlinearities to guarantee that the solution exists globally or blows up at finite time. Moreover, by virtue of the modified differential inequality, upper and lower bounds for the blow‐up time of the solution are derived in higher dimensional spaces. Three examples are presented to illustrate applications of our results. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
Guangwu Wang Boling Guo Shaomei Fang 《Mathematical Methods in the Applied Sciences》2017,40(14):5262-5272
In this paper, we will firstly extend the results about Jiu, Wang, and Xin (JDE, 2015, 259, 2981–3003). We prove that any smooth solution of compressible fluid will blow up without any restriction about the specific heat ratio γ. Then we prove the blow‐up of smooth solution of compressible Navier–Stokes equations in half space with Navier‐slip boundary. The main ideal is constructing the differential inequality. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
3.
Fernando Cortez 《Mathematical Methods in the Applied Sciences》2017,40(4):1333-1345
In this paper, we consider the b‐family of equations on the torus u t ?u t x x +(b + 1)u u x =b u x u x x +u u x x x , which for appropriate values of b reduces to well‐known models, such as the Camassa–Holm equation or the Degasperis–Procesi equation. We establish a local‐in‐space blow‐up criterion. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
4.
On the decay and blow‐up of solution for coupled nonlinear wave equations with nonlinear damping and source terms 下载免费PDF全文
In this work, we consider a nonlinear coupled wave equations with initial‐boundary value conditions and nonlinear damping and source terms. Under suitable assumptions on the damping terms and source terms and initial data in the stable set, we obtain that the decay estimates of the energy function is exponential or polynomial by using Nakao's method. By using the energy method, we obtain the blow‐up result of solution with some positive or nonpositive initial energy. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
Wenyan Chen Xiaoliu Wang Ming Yang 《Mathematical Methods in the Applied Sciences》2017,40(10):3775-3783
Under the shrinking curvature flow with inner normal velocity V = kα(α > 1), it is shown that highly symmetric, locally convex initial curves evolve into a point asymptotically like an multi‐circles. The proof relies on a crucial use of Bonnensen inequality for highly symmetric, locally convex curves. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
Coupling of CFD Simulations and Population Balance Modeling to Predict Brownian Coagulation in an Emulsion Polymerization Reactor 下载免费PDF全文
In this study a framework consisting of a computational fluid dynamics simulation coupled to a population balance model for the modeling of emulsion polymerizations is proposed. The combined approach is used to understand the impact of changing length and time scales, as well as mixing conditions on the particle size distribution (PSD) of a polymer latex under different conditions. It is shown that the effect of agitation rate can have a profound impact on the distribution of ionic species in the reactor, and thus on the evolution of the PSD.
7.
8.
In this paper, we study the stationary problem for the Lotka–Volterra competition system with cross-diffusion in a spatially heterogeneous environment. Although some sufficient conditions for the existence of positive solutions are obtained by using global bifurcation theory, the information for their structure is far from complete. In order to get better understanding of the competition system with cross-diffusion, we focus on the asymptotic behaviour of positive solutions and derive two shadow systems as the cross-diffusion coefficient tends to infinity, moreover, the structure of positive solutions of the limiting system is analysed. The result of asymptotic behaviour also reveals different phenomena from that studied in Wang and Li (2013). 相似文献
9.
10.