全文获取类型
收费全文 | 7297篇 |
免费 | 1007篇 |
国内免费 | 559篇 |
专业分类
化学 | 5123篇 |
晶体学 | 34篇 |
力学 | 386篇 |
综合类 | 16篇 |
数学 | 849篇 |
物理学 | 2455篇 |
出版年
2024年 | 23篇 |
2023年 | 152篇 |
2022年 | 219篇 |
2021年 | 297篇 |
2020年 | 293篇 |
2019年 | 247篇 |
2018年 | 229篇 |
2017年 | 186篇 |
2016年 | 315篇 |
2015年 | 301篇 |
2014年 | 390篇 |
2013年 | 494篇 |
2012年 | 649篇 |
2011年 | 655篇 |
2010年 | 432篇 |
2009年 | 374篇 |
2008年 | 447篇 |
2007年 | 398篇 |
2006年 | 369篇 |
2005年 | 281篇 |
2004年 | 229篇 |
2003年 | 185篇 |
2002年 | 137篇 |
2001年 | 136篇 |
2000年 | 131篇 |
1999年 | 139篇 |
1998年 | 113篇 |
1997年 | 93篇 |
1996年 | 127篇 |
1995年 | 107篇 |
1994年 | 75篇 |
1993年 | 64篇 |
1992年 | 71篇 |
1991年 | 59篇 |
1990年 | 75篇 |
1989年 | 56篇 |
1988年 | 36篇 |
1987年 | 29篇 |
1986年 | 24篇 |
1985年 | 21篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 16篇 |
1981年 | 11篇 |
1979年 | 21篇 |
1978年 | 17篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1973年 | 13篇 |
排序方式: 共有8863条查询结果,搜索用时 0 毫秒
11.
El Kebir Boukas Peng Shi Sing Kiong Nguang 《Journal of Mathematical Analysis and Applications》2003,282(1):241-255
This paper studies the problem of stochastic stability and disturbance attenuation for a class of linear continuous-time uncertain systems with Markovian jumping parameters. The uncertainties are assumed to be nonlinear and state, control and external disturbance dependent. A sufficient condition is provided to solve the above problem. An H∞ controller is designed such that the resulting closed-loop system is stochastically stable and has a disturbance attenuation γ for all admissible uncertainties. It is shown that the control law is in terms of the solutions of a set of coupled Riccati inequalities. A numerical example is included to demonstrate the potential of the proposed technique. 相似文献
12.
Jin Sun Yihu Song Qiang Zheng Hong Tan Jie Yu Hong Li 《Journal of Polymer Science.Polymer Physics》2007,45(18):2594-2602
The reinforcement and nonlinear viscoelastic behavior have been investigated for silica (SiO2) filled solution‐polymerized styrene butadiene rubber (SSBR). Experimental results reveal that the nonlinear viscoelastic behavior of the filled rubber is similar to that of unfilled SSBR, which is inconsistent with the general concept that this characteristic comes from the breakdown and reformation of the filler network. It is interesting that the curves of either dynamic storage modulus (G′) or loss tangent (tan δ) versus strain amplitude (γ) for the filled rubber can be superposed, respectively, on those for the unfilled one, suggesting that the primary mechanism for the Payne effect is mainly involved in the nature of the entanglement network in rubbery matrix. It is believed there exists a cooperation between the breakdown and reformation of the filler network and the molecular disentanglement, resulting in enhancing the Payne effect and improving the mechanical hysteresis at high strain amplitudes. Moreover, the vertical and the horizontal shift factors for constructing the master curves could be well understood on the basis of the reinforcement factor f(φ) and the strain amplification factor A(φ), respectively. The surface modification of SiO2 causes a decrease in f(φ), which is ascribed to weakeness of the filler–filler interaction and improvement of the filler dispersion. However, the surface nature of SiO2 hardly affects A(φ). © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2594‐2602, 2007 相似文献
13.
14.
15.
16.
17.
18.
19.
20.