全文获取类型
收费全文 | 10891篇 |
免费 | 2596篇 |
国内免费 | 1776篇 |
专业分类
化学 | 5036篇 |
晶体学 | 100篇 |
力学 | 757篇 |
综合类 | 123篇 |
数学 | 1316篇 |
物理学 | 7931篇 |
出版年
2024年 | 10篇 |
2023年 | 101篇 |
2022年 | 165篇 |
2021年 | 250篇 |
2020年 | 305篇 |
2019年 | 228篇 |
2018年 | 249篇 |
2017年 | 295篇 |
2016年 | 376篇 |
2015年 | 441篇 |
2014年 | 605篇 |
2013年 | 869篇 |
2012年 | 685篇 |
2011年 | 839篇 |
2010年 | 746篇 |
2009年 | 819篇 |
2008年 | 908篇 |
2007年 | 912篇 |
2006年 | 767篇 |
2005年 | 723篇 |
2004年 | 546篇 |
2003年 | 593篇 |
2002年 | 556篇 |
2001年 | 459篇 |
2000年 | 423篇 |
1999年 | 406篇 |
1998年 | 309篇 |
1997年 | 257篇 |
1996年 | 227篇 |
1995年 | 173篇 |
1994年 | 162篇 |
1993年 | 138篇 |
1992年 | 122篇 |
1991年 | 103篇 |
1990年 | 62篇 |
1989年 | 77篇 |
1988年 | 53篇 |
1987年 | 43篇 |
1986年 | 21篇 |
1985年 | 52篇 |
1984年 | 28篇 |
1983年 | 18篇 |
1982年 | 42篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1979年 | 14篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 10篇 |
1973年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
相位差与q变形广义相干叠加态的压缩特性 总被引:1,自引:0,他引:1
对于q变形的非简谐振子广义相干态的叠加态β〉+eiφβeiδ〉,其量子涨落的可能高阶压缩阶数可以表示为k≠2πn/δ,这里n是整数.当δ=π时,压缩阶数不能是偶数即只能是奇数,这正是q变形非简谐振子广义奇偶相干态的结果.由此表明参数相位差δ对决定q变形的非简谐振子广义相干态叠加态的高阶压缩阶数起决定性作用. 相似文献
52.
J.O. Andersen 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,28(4):389-396
We consider an interacting homogeneous Bose gas at zero temperature in two spatial dimensions. The properties of the system
can be calculated as an expansion in powers of g, where g is the coupling constant. We calculate the ground state pressure and the ground state energy density to second order in the
quantum loop expansion. The renormalization group is used to sum up leading and subleading logarithms from all orders in perturbation
theory. In the dilute limit, the renormalization group improved pressure and energy density are expansions in powers of the
T
2B and T
2Bln(T
2B), respectively, where T
2B is the two-body T-matrix.
Received 19 April 2002 Published online 13 August 2002 相似文献
53.
54.
提出一种利用 GHZ态实现多原子缠结态的量子隐形传态方案 .当作为量子通道的 GHZ态含有一个单模高 Q腔时 ,大大地简化了量子稳形传态中的联合测量过程 相似文献
55.
导出了类Kerr介质中双模SU(1,1)相干态场与Λ型三能级原子相互作用系统的态函数,研究了Kerr效应对Λ型三能级原子布居概率、双模SU(1,1)相干态场的互关联函数、Cauchy-Schwartz不等式及二阶相干度的影响.结果表明:Kerr效应使原子与光场的耦合减弱,原子布居的崩塌与复苏的周期缩短;在初始光场较弱和较强两种情况下,类Kerr介质对双模SU(1,1)相干态场两模间的相关性、相关程度以及光子的聚束与反聚束效应产生的作用有明显的区别. 相似文献
56.
57.
A. Shaporenko A. Terfort M. Grunze M. Zharnikov 《Journal of Electron Spectroscopy and Related Phenomena》2006
Analysis of photoemission spectra of complex thioaromatic self-assembled monolayers (SAMs) requires the knowledge and understanding of such spectra for the basic systems. Keeping this goal in mind, synchrotron-based high-resolution X-ray photoelectron spectroscopy was used to characterize SAMs formed from the simplest thioaromatic compounds, namely thiophenol, 1,1′-biphenyl-4-thiol and 1,1′;4′,1″-terphenyl-4-thiol on evaporated Au(1 1 1) and Ag(1 1 1) substrates. The acquired S 2p and C 1s spectra were analyzed in terms of fine structure and initial and final state effects in the photoemission process. The assignment of the individual spectral features was considered in detail. Conclusions on quality and chemical and structural homogeneity of the investigated SAMs were derived. 相似文献
58.
A probabilistic teleportation scheme for atomic state via cavity QED [Phys. Rev. A 70 (2004) 054303] is revisited and accordingly some improvements are made. 相似文献
59.
Andreas Lüttge 《Journal of Electron Spectroscopy and Related Phenomena》2006,150(2-3):248-259
The dependence of dissolution rates on the difference of Gibbs free energy is of critical importance for our understanding of crystal dissolution, reactive flow models and their applications to a variety of environmentally related problems. Here, we review experimental data generated with mineral powders and single crystals to develop a better understanding of apparent inconsistencies between otherwise internally consistent data sets. Additional information from direct surface observations and measurements with vertical scanning interferometry (VSI) and atomic force microscopy (AFM) of albite dissolution at 25, 150 and 185 °C may shed new light on this old but unsolved question. Our discussion is based on the importance of etch pit development, its ΔG dependence, and the pits’ role as a source for steps and step movement in the dissolution process. Results indicate that reaction history may be of critical importance in determining the overall reaction mechanism and its rate. Different rates are observed for systems having otherwise identical ΔGr acquired from increasing versus decreasing disequilibrium positions.
In this context, we finally discuss the validity of the common application of transition state theory (TST) to elementary and overall reactions governing the dissolution process. In this discussion of crystal dissolution, we contrast TST applications with a stochastic, many-body treatment that has led to the development of a stepwave model. This discussion also focuses on the controversy caused by the rivalry between surface adsorption models and a probabilistic model that seeks to incorporate the full three-dimensional crystal structure. 相似文献
60.
q变形对相干态的相位概率分布特性 总被引:2,自引:0,他引:2
通过推广Pegg和Barnett的相位算符和相位态到q变形的双模情况, 应用数值计算
研究了q变形对相干态的相位概率分布特性. 结果表明, q变形对相干态的相位概率分布受到相位参数、q参数和参数│ξ│的调节, 从而反映出不同的量子相干特性. 相似文献