全文获取类型
收费全文 | 89篇 |
免费 | 0篇 |
专业分类
化学 | 40篇 |
数学 | 3篇 |
物理学 | 46篇 |
出版年
2020年 | 1篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2013年 | 3篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有89条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
A great number of studies of polyelectrolyte complexes have been carried out by various investigators; most of them concentrated on the reaction between oppositely charged polyelectrolytes [1-3]. The structure and properties of the resultant complexes have been investigated to a lesser extent, and the understanding of this new class of polymer materials is still insufficient. Thus, we have been investigating the sorption of water vapor by the complexes and the morphological changes caused by this sorption [4,5]. 相似文献
5.
The movement and relaxation of the localized energy on FPU lattices have been studied by using Wavelet transforms methods. The energy relaxation mechanism for nonlinear chains involves the degradation of higher frequency excitations into lower frequencies. It is shown that low frequency modes decay more slowly in nonlinear chains. The wavelet spectrum exhibits a behavior involving the interplay of phonon modes and breather modes. 相似文献
6.
In our previous paper Ohkuwa et al. (2016) corrigendum was found in Eqs. (3.4) and (3.6). However, conclusions of our previous paper are not changed. 相似文献
7.
Tetsuya Ezawa Seunghee Jung Yuya Kawashima Takuya Noguchi Nobuyuki Imai 《Tetrahedron: Asymmetry》2017,28(1):75-83
Dipeptides and amides were obtained in high yields from N-carbobenzyloxy α-amino acids and 3-phenylpropanoic acid with unprotected α-amino acids via the corresponding mixed carbonic carboxylic anhydrides using ethyl chloroformate and triethylamine by an ecological and convenient method in which the protection of C-terminals is not needed. 相似文献
8.
Previously, O-selective phosphorylation on polymer supports in the N-unprotected phosphoramidite method could not be carried out because the amino groups of dA and dC have high reactivity toward tervalent phosphorus(III)-type phosphitylating reagents. In this paper, we developed a new coupling strategy named the "activated phosphite method" in which the phosphitylation is mediated by phosphite triester intermediates 1. Application of 1-hydroxybenzotriazole as the promoter to the solid-phase synthesis resulted in excellent O-selectivity of more than 99.7%. This O-selectivity was explained by the frontier molecular orbital interactions between the reactive intermediates and the nucleophiles such as the amino or hydroxyl groups of nucleosides. Furthermore, longer oligonucleotides were synthesized not only by a manual operation but also by a DNA synthesizer. The utility of our new method was demonstrated by the successful synthesis of a base-labile modified oligodeoxyribonucleotide having 4-N-acetyldeoxycytidine residues. Finally, DNA 20-mers containing dA or dC could be synthesized in good yields by use of a combined reagent of 6-trifluoromethyl-1-hydroxybenzotriazole and benzimidazolium triflate. 相似文献
9.
We formulate the concepts of instantons, multiple vacua and vacuum tunnelling in the canonical framework. This formalism enables us to give explicit expressions for previously unconsidered relations between the physical and unphysical sectors of the indefinite metric Hilbert space. As concrete examples we discuss the Higgs, Schwinger and Nambu-Jona-Lasinio models. 相似文献
10.
Zyun F. Ezawa 《Nuclear Physics B》1973,58(1):295-300
It is shown, in a scalar current model, that the Drell-Yan-West relations is valid in the form of an inequality. Namely, it is proved that the elastic form factor decreases asymptotically as, or more rapidly than, , provided that the deep-inelastic structure function behaves near threshold as ~(1 ? ω)l ? 1. 相似文献