全文获取类型
收费全文 | 792篇 |
免费 | 11篇 |
国内免费 | 3篇 |
专业分类
化学 | 515篇 |
晶体学 | 3篇 |
力学 | 9篇 |
数学 | 111篇 |
物理学 | 168篇 |
出版年
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 23篇 |
2009年 | 16篇 |
2008年 | 49篇 |
2007年 | 37篇 |
2006年 | 41篇 |
2005年 | 19篇 |
2004年 | 33篇 |
2003年 | 27篇 |
2002年 | 22篇 |
2001年 | 26篇 |
2000年 | 18篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 16篇 |
1996年 | 18篇 |
1995年 | 11篇 |
1994年 | 16篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 16篇 |
1990年 | 14篇 |
1989年 | 18篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1974年 | 13篇 |
1973年 | 14篇 |
1972年 | 11篇 |
1971年 | 11篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1934年 | 5篇 |
排序方式: 共有806条查询结果,搜索用时 0 毫秒
801.
Köhler SP Reed SK Westacott RE McKendrick KG 《The journal of physical chemistry. B》2006,110(24):11717-11724
Molecular dynamics simulations of liquid squalane, C30H62, were performed, focusing in particular on the liquid-vacuum interface. These theoretical studies were aimed at identifying potentially reactive sites on the surface, knowledge of which is important for a number of inelastic and reactive scattering experiments. A united atom force field (Martin, M. G.; Siepmann, J. I. J. Phys. Chem. B 1999, 103, 4508-4517) was used, and the simulations were analyzed with respect to their interfacial properties. A modest but clearly identifiable preference for methyl groups to protrude into the vacuum has been found at lower temperatures. This effect decreases when going to higher temperatures. Additional simulations tracking the flight paths of projectiles directed at a number of randomly chosen surfaces extracted from the molecular dynamics simulations were performed. The geometrical parameters for these calculations were chosen to imitate a typical abstraction reaction, such as the reaction between ground-state oxygen atoms and hydrocarbons. Despite the preference for methyl groups to protrude further into the vacuum, Monte Carlo tracking simulations suggest, on geometric grounds, that primary and secondary hydrogen atoms are roughly equally likely to react with incoming gas-phase atoms. These geometric simulations also indicate that a substantial fraction of the scattered products is likely to undergo at least one secondary collision with hydrocarbon side chains. These results help to interpret the outcome of previous measurements of the internal and external energy distribution of the gas-phase OH products of the interfacial reaction between oxygen atoms and liquid squalane. 相似文献
802.
Jeffrey T. La Belle Miti Shah Justin Reed Vivek Nandakumar T. L. Alford James W. Wilson Cheryl A. Nickerson Lokesh Joshi 《Electroanalysis》2009,21(20):2267-2271
An immunosensor for rapid and low level detection of the bacterial pathogen Salmonella enterica Serovar Typhimurium was designed and developed based upon label‐free electrochemical impedance spectroscopy and correlated to viable cell counts. The immunosensor was fabricated by electroplating gold onto a disposable printed circuit board (PCB) electrode by immobilizing monoclonal antibody (MAb) specific against Salmonella typhimurium cell surface lipopolysaccharide (LPS) onto the surface of the electrode. Use of mass‐fabricated and electroplated PCB electrodes allowed for disposable, highly sensitive, and rapid detection of Salmonella in an aqueous environment. Results demonstrate that in purified solution, Salmonella can be detected as low as 10 CFU in a 100 μL volume and label‐free and rapid manner in fewer than 90 s. The cost effective approach described here can be used for detection of pathogens with relevance for healthcare, food, and environmental applications. 相似文献
803.
Simon Duttwyler Yun Zhang Anthony Linden Priv.‐Doz. Dr. Christopher A. Reed Prof. Kim K. Baldridge Prof. Jay S. Siegel Prof. 《Angewandte Chemie (International ed. in English)》2009,48(21):3787-3790
Sly silyl caught in the act : Protonation of a mesitylene ring by the strongly acidic arenium carborane [CH3C6H6]‐ [CHB11Me5Br6] initiates a cascade reaction that results in a stable β‐silyl allyl cation (see picture, H yellow, C blue, silyl allyl group red). Remarkably, the driving force in the reaction suffices to disrupt a stable aromatic ring in favor of a cationic reactive intermediate.
804.
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) react with chloro- and dichloro-phosphines leading to onio- and dionio-substituted phosphines. Similarly, onio-substituted silicon and tin derivatives are prepared; they are used as onio-substituent transfer reagents in the synthesis of a trionio-substituted phosphine. 相似文献
805.
Single crystals of (Me4N)4 [UO2(CO3)3]·8H2O are grown by slow evaporation (25 °C, 6 weeks) of an aqueous solution of uranyl 1‐hydroxyethane‐1,1‐diphosphonate and Me4NOH. 相似文献
806.
Wayne F. Reed 《Macromolecular Symposia》2002,190(1):131-150
An overview of recent developments in TDSLS and auxiliary techniques is given. This includes background theory, and examples of results and applications for online monitoring of polymerization reactions, kinetics and structural determinations from degrading polymers, aggregation, and dissolution of dry polymer powders. Also, automatic dilution techniques allow for continuous characterization of the equilibrium states of multi-component solutions. Illustrations are given for the case where the change in polyelectrolyte dimensions, interactions and hydrodynamics can be probed. 相似文献