全文获取类型
收费全文 | 4187篇 |
免费 | 209篇 |
国内免费 | 45篇 |
专业分类
化学 | 2961篇 |
晶体学 | 48篇 |
力学 | 137篇 |
综合类 | 2篇 |
数学 | 414篇 |
物理学 | 879篇 |
出版年
2024年 | 42篇 |
2023年 | 73篇 |
2022年 | 399篇 |
2021年 | 325篇 |
2020年 | 199篇 |
2019年 | 203篇 |
2018年 | 191篇 |
2017年 | 146篇 |
2016年 | 234篇 |
2015年 | 159篇 |
2014年 | 189篇 |
2013年 | 314篇 |
2012年 | 266篇 |
2011年 | 296篇 |
2010年 | 178篇 |
2009年 | 150篇 |
2008年 | 170篇 |
2007年 | 137篇 |
2006年 | 114篇 |
2005年 | 96篇 |
2004年 | 67篇 |
2003年 | 68篇 |
2002年 | 70篇 |
2001年 | 26篇 |
2000年 | 28篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 24篇 |
1995年 | 29篇 |
1994年 | 11篇 |
1993年 | 12篇 |
1992年 | 22篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1979年 | 6篇 |
1978年 | 13篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1972年 | 7篇 |
1971年 | 6篇 |
排序方式: 共有4441条查询结果,搜索用时 15 毫秒
951.
952.
Muhammad Aslam Noor 《Journal of Mathematical Analysis and Applications》2003,283(1):140-149
In this paper, we use the auxiliary principle technique to suggest some new classes of iterative algorithms for solving multivalued equilibrium problems. The convergence of the proposed methods either requires partially relaxed strongly monotonicity or pseudomonotonicity. As special cases, we obtain a number of known and new results for solving various classes of equilibrium and variational inequality problems. Since multivalued equilibrium problems include equilibrium, variational inequality and complementarity problems as specials cases, our results continue to hold for these problems. 相似文献
953.
Samuel Varghese Muhammed Iqbal Suresh Nair V. P. N. Nampoori C. P. G. Vallabhan 《Fiber and Integrated Optics》2007,26(5):245-254
A new method for the fabrication of a monolithic 1 × 4 single-mode fused coupler is described together with details of its performance in terms of coupling ratio, spectral response and polarization sensitivity. The fabricated device exhibits ultra-broadband performance with low polarization dependent loss. The coupling pattern exhibits identical coupling to all interacting fibers, enabling an easy control on fabrication parameters of the device. 相似文献
954.
Muhammad Taher Abuelma'atti 《Fiber and Integrated Optics》2006,25(2):75-86
Large signal analysis of the multiple-quantum-well electroabsorption modulators driven by a mutisinusoidal RF signal is presented. The special case of a two-tone equal-amplitude RF signal is considered in detail and the results are compared with previously published results. 相似文献
955.
The polycrystalline samples of Pb(Li1/4Dy1/4W1/2)O3 have been synthesized by high-temperature solid-state reaction techniques. Room temperature X-ray diffraction (XRD) studies
of the compound provided preliminary structural data, and hence formation of a single phase desired material was confirmed.
Detailed studies of dielectric constant (ε) and loss (tanδ) as a function of frequency (100 Hz to 10 kHz) at room temperature (298 K) and also as a function of temperature (liquid
nitrogen to 403 K) at 10 kHz suggest that the compound undergoes a ferroelectric phase transition of diffuse type. 相似文献
956.
LetI =xεR: 0≤x≤∞ be the locally compact semigroup with addition as binary operation and the usual interval topology. The purpose of this note is to study the algebraA p(I) of elements inL 1(I) whose Gelfand transforms belong toL p(Î), whereÎ denotes maximal ideal space ofL 1(I). The multipliers ofA p(I) have also been identified. 相似文献
957.
The present paper is concerned with the dynamic problem of a homogeneous isotropic half-space with voids subjected to a set of normal point sources. The integral transforms have been inverted by using a numerical technique to obtain the normal force stress, normal displacement, tangential couple stress and volume fraction field in the physical domain for the two different sources. The expressions of these quantities have been given and illustrated graphically to depict the effect of micropolarity and voids. 相似文献
958.
In this paper, we use a modified form of the Sine–Cosine method for obtaining exact soliton solutions of the generalized fifth-order nonlinear evolution equation. Analysis for this method is presented. The present method shows that the solutions involve either sec2 or sech2 under certain conditions. General forms of those conditions are determined for the first time. Exact solutions for special cases of this problem such as the Sawada-Kotera and Lax equations are determined and found to be compared well with the previous studies. 相似文献
959.
Alverson G Baker WF Ballocchi G Benson R Berg D Blusk S Bromberg C Brown D Carey D Chand T Chandlee C Choudhary BC Chung WH de Barbaro L DeSoi W Dlugosz W Dunlea J Easo S Engels E Faissler W Fanourakis G Ferbel T Garelick D Ginther G Glass G Glaubman M Gutierrez P Hartman K Huston J Johnstone C Kapoor V Kourbanis I Lanaro A Lirakis C Lobkowicz F Lukens P Mani S Maul A Mansour J Miller R Nelson CA Oh B Orris D Pothier E Prebys E Rajaram BM Roser R Ruddick K Shepard P Shivpuri RK Sinanidis A 《Physical review letters》1992,68(17):2584-2587
960.