全文获取类型
收费全文 | 272篇 |
免费 | 28篇 |
国内免费 | 1篇 |
专业分类
化学 | 216篇 |
力学 | 2篇 |
数学 | 8篇 |
物理学 | 24篇 |
无线电 | 51篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 16篇 |
2014年 | 12篇 |
2013年 | 10篇 |
2012年 | 26篇 |
2011年 | 21篇 |
2010年 | 10篇 |
2009年 | 16篇 |
2008年 | 15篇 |
2007年 | 10篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 19篇 |
2001年 | 8篇 |
2000年 | 17篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
排序方式: 共有301条查询结果,搜索用时 15 毫秒
71.
72.
Kaliyamoorthy Panneerselvam Tian‐Huey Lu Ta‐Yung Chi Shu‐Fang Tung Chung‐Sun Chung 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e128-e129
The crystal structure of the title compound, [CoCl(C18H37N4O2){ZnCl3}], has been determined by X‐ray diffraction.C‐meso‐5,5,7,12,12,14‐Hexamethyl‐1,4,8,11‐tetraazacyclotetradecane‐N‐acetate acts as a bridging ligand to coodinate with CoIII and ZnII ions. The CoIII ion is six‐coordinate in a nearly octahedral environment provided by one Cl atom, four N atoms of the bridging ligand, and one O atom. The ZnII ion is four‐coordinate in a distorted tetrahedral environment completed by three Cl atoms and an O atom of the bridging ligand. 相似文献
73.
Convergence in the telecommunications industry provides an excellent platform and opportunity for new context-aware services.
Context awareness, i.e. being able to harvest environmental information and use it to meet or anticipate user needs, is a
key enabler for personalised applications and services that will be attractive to users in the future. This paper explores
relevant research studies that have been undertaken, and proposes a new architecture for realisation of a context-aware system. 相似文献
74.
75.
Jiun Shiu Ja-Ling Wu 《Communications, IEEE Transactions on》1996,44(3):281-283
A majority decoding algorithm for a class of real-number codes is presented. Majority decoding has been a relatively simple and fast decoding technique for codes over finite fields. When applied to decode real-number codes, the robustness of the majority decoding to the presence of background noise, which is usually an annoying problem for existing decoding algorithms for real-number codes, is its most prominent property. The presented class of real-number codes has generator matrices similar to those of the binary Reed-Muller codes and is decoded by similar majority logic 相似文献
76.
77.
78.
F. C. Hoh 《International Journal of Theoretical Physics》2000,39(4):1069-1084
An expression for the decay rate (0 ) has been derived in the frameworkof the spinor strong interaction theory, a first-principles strong interaction theoryproposed some years ago as an alternative to low-energy QCD. The startingpoint is the SO(3) gauge-invariant action for two quark mesons which has beensuccessful in accounting for confinement, + + , e+, and 0 e+, nonexistenceof the Higgs boson, and other low-energy mesonic phenomena. The quasi-four-quarkmeson equations developed for the decay of a vector meson into twopseudoscalar mesons V PP has been taken over here to apply to P(0) VV(+ –) (plus + and – which annihilate each other). This mechanismin principle agrees with that of the assumption of vector meson dominance inthe literature. It, together with the effect of form factors, arises naturally in theformalism and need not be assumed. Equations for the perturbed vector mesonwave functions cannot be simply solved and an assumption has been made toobtain an estimate of their magnitude. Together with a constant associated withthe strong coupling obtained earlier from V() PP(K+K–), the estimated decayrate is 19.2 eV, in order-of-magnitude agreement with data (7.74 eV). 相似文献
79.
The acoustic wave generated in silicon crystal during laser annealing has been observed. The acoustic signal increases superlinearly with incident laser energy beyond the melting threshold. This can be used for monitoring the state of melting during the annealing. 相似文献
80.
J.-M. Flaud C. Camy-Peyret K. Narahari Rao Da-Wun Chen Yan-Shek Hoh J.-P. Maillard 《Journal of Molecular Spectroscopy》1979,75(3):339-362
Measurements of the line positions of H216O in the 8050 to 9370 cm?1 region have been performed at a spectral resolution of 0.07 cm?1. A grating spectrum of room-temperature water vapor and a Fourier transform spectrum of heated water vapor (T ? 60°C) were used in the interpretation. A careful analysis of the bands ν1 + 3ν2, 3ν2 + ν3, 2ν1 + ν2, ν1 + ν2 + ν3, and ν2 + 2ν3 has led to a set of rotational levels belonging to the vibrational states (130), (031), (210), (111), and (012). Many vibrorotational resonances were detected. 相似文献