全文获取类型
收费全文 | 706篇 |
免费 | 12篇 |
国内免费 | 2篇 |
专业分类
化学 | 374篇 |
晶体学 | 9篇 |
力学 | 69篇 |
数学 | 100篇 |
物理学 | 168篇 |
出版年
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 28篇 |
2012年 | 27篇 |
2011年 | 34篇 |
2010年 | 18篇 |
2009年 | 21篇 |
2008年 | 27篇 |
2007年 | 35篇 |
2006年 | 30篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 9篇 |
2002年 | 22篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 16篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1977年 | 9篇 |
1976年 | 18篇 |
1975年 | 16篇 |
1974年 | 16篇 |
1973年 | 12篇 |
1971年 | 8篇 |
排序方式: 共有720条查询结果,搜索用时 328 毫秒
71.
J.R. Owen W.C. Maskell B.C.H. Steele T.Steen Nielsen O.Toft Sørensen 《Solid State Ionics》1984,13(4):329-334
LiAl thin film electrodes were formed by cathodic conversion of the surface of a 50 micron Al foil in a propylene carbonate based electrolyte. The films were cycled both in Li-doped poly(ethylene oxide) and propylene carbonate. On charging, an overpotential of 40 mV was required to sustain growth of the LiAl phase, but the diffusional overpotential was minimal. A simple diffusional model for the discharge predicted serious rate limitation due to slow diffusion in the α phase. However, measurements of the diffusion coefficient gave values many orders higher than previously reported and even greater values were required to explain the discharge rates. Cycling behaviour showed that the electrode degradation was less severe in the polymeric electrolyte than in propylene carbonate. 相似文献
72.
Thermally stimulated recovery behaviour of amorphous polymers is described in terms of a continuous distribution of sharply defined elementary softening processes in the polymer. It is proposed that each of these elementary processes is the result of a co-operative site-change mechanism. On exceeding the activation temperature for the process, the viscoelastic time constants fall abruptly by many orders of magnitude, as opposed to following an Arrhenius-type law. The implications of this type of behaviour are discussed.
Prof. Schwarzl zum 60. Geburtstag gewidmet. 相似文献
73.
74.
J. D. Owen 《Acta Crystallographica. Section C, Structural Chemistry》1983,39(5):579-582
75.
76.
M. Ambrosio G. Anzivino G. Barbarino G. Carboni V. Cavasinni T. Del Prete P.D. Grannis D. Lloyd Owen M. Morganti G. Paternoster S. Patricelli M. Valdata-Nappi 《Physics letters. [Part B]》1982,115(6):495-502
We measured the differential cross section for p?p and pp elastic scattering in the momentum-transfer range 0.01 <|t| < 1.0 GeV2 at the CERN Intersecting Storage Rings with center-of-mass energy . Fitting the differential cross section with an exponential [Aexp (bt)], we found for |t| < 0.05 GeV2, whilst for |t| > 0.09 GeV2, . Using the optical theorem, we obtained for the total cross section and, by integrating the differential cross section, we obtained for the total elastic cross section . Calculations of σtot combining elastic-rate and total-rate measurements are also given. All of these measurements were also performed for pp scattering at the same energy, and the results for both reactions are compared. 相似文献
77.
The direct irradiation of the monomethoxybarrelene 8 gives cyclooctatetraene product 18 (Φ = 0.075) via the anti-Epiotis aromatic-vinyldiester [2π+2π] bridging route, and two semibullvalenes 16 (Φ = 0.075) and 17 (Φ = 0.075) from di-π-methane rearrangements initiating from vinyl-vinyldiester bridging. Benzophenone sensitization yields 16 (Φ =0.11) and 17 (Φ = 0.11). The dimethoxybarrelene 9 gives only semibullvalene 10 , this resulting from di-π-methane rearrangement involving the vinyl and vinyldiester bridges, upon direct (Φ = 0.009) or benzophenone sensitized irradiations (Φ = 0.38). 10 undergoes a vinylcyclopropane rearrangement to give semibullvalene 11 upon direct or acetone sensitized irradiations (Φ = 0.008). 相似文献
78.
79.
80.
G. Kalai Professor M. Maschler Professor G. Owen 《International Journal of Game Theory》1975,4(4):193-213
The foundation of a dynamic theory for the bargaining sets started withStearns, when he constructed transfer sequences which always converge to appropriate bargaining sets. A continuous analogue was developed byBillera, where sequences where replaced by solutions of systems of differential equations. In this paper we show that the nucleolus is locally asymptotically stable both with respect toStearns' sequences andBillera's solutions if and only if it is an isolated point of the appropriate bargaining set. No other point of the bargaining set can be locally asymptotically stable. Furthermore, it is always stable in these processes. As by-products of the study we derive the results ofBillera andStearns in a different fashion. We also show that along the non-trivial trajectories and sequences, the vector of the excesses of the payoffs, arranged in a non-increasing order, always decreases lexicographically, thus each bargaining set can be viewed as resulting from a certain monotone process operating on the payoff vectors. 相似文献