全文获取类型
收费全文 | 542篇 |
免费 | 12篇 |
国内免费 | 6篇 |
专业分类
化学 | 323篇 |
晶体学 | 25篇 |
力学 | 9篇 |
数学 | 66篇 |
物理学 | 137篇 |
出版年
2022年 | 4篇 |
2019年 | 9篇 |
2018年 | 4篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 25篇 |
2011年 | 34篇 |
2010年 | 27篇 |
2009年 | 10篇 |
2008年 | 18篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 29篇 |
2004年 | 13篇 |
2003年 | 20篇 |
2002年 | 23篇 |
2001年 | 11篇 |
2000年 | 21篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 3篇 |
1973年 | 10篇 |
1972年 | 3篇 |
1970年 | 3篇 |
1969年 | 8篇 |
1968年 | 4篇 |
1967年 | 3篇 |
1943年 | 3篇 |
1888年 | 2篇 |
排序方式: 共有560条查询结果,搜索用时 0 毫秒
91.
M D Stevenson J E Brazier N W Calvert M Lloyd-Jones J E Oakley J A Kanis 《The Journal of the Operational Research Society》2005,56(2):214-221
Models of the cost-effectiveness of pharmaceutical interventions for the treatment of osteoporosis have traditionally adopted cohort-based approaches. We present a transition-state model to simulate the experience of individual patients, allowing the full patient history and residential status to influence the probabilities of future fractures at the hip, spine, wrist or proximal humerus. Alongside epidemiological data, we used systematic literature reviews of costs, utilities and efficacy to populate the model for a UK setting. We established a statistical relationship between the inputs and outputs of the individual patient model creating a near instantaneous emulation of the individual patient model. We undertook extensive sensitivity analyses to analyse the uncertainty in the estimated incremental cost per quality-adjusted life year due to uncertainty in the efficacy of the drugs. We provide illustrative results accompanied by individual and multi-interventional cost-effectiveness acceptability curves. 相似文献
92.
93.
P.M. Stevenson 《Physics letters. [Part B]》1981,100(1):61-64
Next-to-leading-order QCD predictions depend on the arbitrary choice of renormalisation scheme. I resolve this ambiguity and show how to find the unique, optimum prediction, given the result in some arbitrary, initial scheme. 相似文献
94.
A stereoselective synthesis procedure for lignans of the all-trans αα'-diaryl-ββ'-dimethyltetrahydrofurans is described. The lignans, galbelgin (4) and grandisin (37) were synthesized by routine reduction of the tetrahydrofuran dicarboxylic esters (24 and 34), obtained by mild acid treatment of the readily available diaryl dilactones (23 and 33). 相似文献
95.
D.J. Stevenson 《Physics letters. A》1976,58(4):282-284
Binary alloys in which all the electrons form a uniform, degenerate, non-relativistic gas are predicted to exhibit miscibility gaps. Approximate analytical formulae are given for the critical temperatures and compositions. Astrophysical implications are mentioned. 相似文献
96.
A relationship is derived between CN concentration and atomization efficiency in the C2H2-N2O flame. The relationship is examined under various experimental conditions and β values are estimated for a number of elements. The possibility of complex vapour phase oxide formation by U is considered. 相似文献
97.
98.
The acid-catalyzed rearrangement of diaryl-dilactones, readily obtained by oxidation of ferulic acid derivatives, is examined as a synthesis route to aryltetralins. Two structures which have been proposed for the lignan, phyltetralin, are shown by synthesis of the two diastereomeric 1-veratryltetralins (3A) and (3B), to be untenable. Conidendrin has been converted to isolariciresinol tetramethyl ether (21) and comparison of empirical constants and spectra with those reported for phyltetralin strongly suggest that the lignan has the enantiomeric constitution (26). 相似文献
99.
A. Stevenson 《Journal of Polymer Science.Polymer Physics》1983,21(4):553-572
When natural rubber crystallizes at low temperatures, there is an increase in elastic modulus of up to two orders of magnitude. This phenomenon has been studied at various temperatures in the range 0 to ?55°C for samples held at tensile strains of up to 500%. There is an induction period associated with the nucleation of crystallites, before any increase in modulus is observed. The induction period increases with decreasing strain and passes through a minimum with increasing temperature at ?25°C. The growth rate subsequent to nucleation is successfully described in terms of Avrami-type rate relationships. The Avrami rate coefficient is independent of temperature and follows a simple exponential function of strain. The equilibrium extent of the modulus increase has also been studied by means of experiments of up to three months' duration. The equilibrium modulus increases with decreasing temperature—as predicted by Flory's thermodynamic theory. 相似文献
100.
Regenerated gratings seeded by type I gratings in boron-codoped germanosilicate optical fiber written with 193 nm are shown to withstand temperatures beyond 1000 degrees C. 相似文献