全文获取类型
收费全文 | 9703篇 |
免费 | 2121篇 |
国内免费 | 1666篇 |
专业分类
化学 | 4945篇 |
晶体学 | 99篇 |
力学 | 587篇 |
综合类 | 117篇 |
数学 | 1166篇 |
物理学 | 6576篇 |
出版年
2024年 | 9篇 |
2023年 | 93篇 |
2022年 | 154篇 |
2021年 | 221篇 |
2020年 | 289篇 |
2019年 | 207篇 |
2018年 | 217篇 |
2017年 | 260篇 |
2016年 | 322篇 |
2015年 | 392篇 |
2014年 | 527篇 |
2013年 | 780篇 |
2012年 | 588篇 |
2011年 | 727篇 |
2010年 | 651篇 |
2009年 | 735篇 |
2008年 | 789篇 |
2007年 | 811篇 |
2006年 | 709篇 |
2005年 | 656篇 |
2004年 | 488篇 |
2003年 | 540篇 |
2002年 | 481篇 |
2001年 | 398篇 |
2000年 | 376篇 |
1999年 | 350篇 |
1998年 | 253篇 |
1997年 | 221篇 |
1996年 | 194篇 |
1995年 | 151篇 |
1994年 | 154篇 |
1993年 | 111篇 |
1992年 | 110篇 |
1991年 | 94篇 |
1990年 | 49篇 |
1989年 | 71篇 |
1988年 | 43篇 |
1987年 | 39篇 |
1986年 | 20篇 |
1985年 | 48篇 |
1984年 | 26篇 |
1983年 | 15篇 |
1982年 | 33篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 14篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1974年 | 4篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
MAIO Hong GAO Chong-Shou ZHUANG Peng-Fei 《理论物理通讯》2006,46(12)
Bound states, such as qq and q(q), may exist in quark-gluon plasma. As the system is at high density,the volume of the bound states may evoke a reduction in the phase space. We introduce an extended bag model to investigate qualitatively the volume effect on the properties of the system. We find a limit temperature where the bound states start to be completely melted. 相似文献
42.
采用固相反应合成了四羟基苯基卟啉与与Fe^2+,Co^2+金属离子的配合物,在室温下,将其与分子O2作用,提纯后得到两种固态氧合配合物.通过元素分析、红外光谱(IR)、核磁共振氢谱(^1HNMR)、电导、热分析(TG/DTA)、紫外光谱(UV)等测试手段确定了氧合配合物的组成为[Co·THPP·O2](NO3)2·2H2O、[Fe·THPP·O2]Cl2·2H2O],可知1mol配合物吸收了1molO2,采用失重法测定了氧合配合物中的配位氧,确定1mol金属配合物吸收1molO2形成超氧配合物. 相似文献
43.
The knowledge of hydrocarbon/water phase equilibria is important in the design and operation of equipment for petroleum transport and refining and petrochemical plants. The presence of water in a hydrocarbon mixture can affect the product quality and damage the operation equipment due to corrosion and formation of gas hydrates. Tracing the concentration of hydrocarbons in aqueous media is also important for technical purposes like preventing oil spills and for ecological concerns such as predicting the fate of these organic pollutants in the environment. 相似文献
44.
Wilson A. Cañas-Marín Julián D. Ortiz-Arango Uriel E. Guerrero-Aconcha Claudia P. Soto-Tavera 《Fluid Phase Equilibria》2007
The ability of Soave–Redlich–Kwong cubic equation of state (SRK EoS) to predict densities and thermodynamic derivative properties such as thermal expansivity, isothermal compressibility, calorific capacity, and Joule–Thompson coefficients, for two gas condensates over a wide range of pressures (up to 110 MPa) was studied. The predictions of the EoS were compared to Monte Carlo simulation data obtained by Lagache et al. [M.H. Lagache, P. Ungerer, A. Boutin, Fluid Phase Equilibr. 220 (2004) 221]. Two completely different alpha functions for the SRK EoS attractive term were used and their respective effects on the predictions of such properties were analyzed. Also, two different forms of the crossed terms of the attractive parameter, aij, and three expressions of the crossed terms of the repulsive parameter, bij, were combined in different ways, and predictions were carried out. Little sensitivity of the properties on the chosen alpha function, except for the calorific capacities, was found in the systems studied. The most commonly used combination rules to model phase behavior of reservoir fluids, i.e. geometric and arithmetic forms of aij and bij, respectively, predicted very deficient results for these fluids at extreme conditions, specially for density calculations. 相似文献
45.
46.
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
47.
48.
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
49.
50.
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