全文获取类型
收费全文 | 537篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
化学 | 413篇 |
晶体学 | 12篇 |
力学 | 8篇 |
数学 | 40篇 |
物理学 | 95篇 |
出版年
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 11篇 |
2013年 | 34篇 |
2012年 | 19篇 |
2011年 | 30篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 50篇 |
2007年 | 29篇 |
2006年 | 33篇 |
2005年 | 27篇 |
2004年 | 24篇 |
2003年 | 20篇 |
2002年 | 20篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1962年 | 2篇 |
排序方式: 共有568条查询结果,搜索用时 31 毫秒
171.
Michio Ashida Yasukiyo Ueda Hisao Yanagi Koichi Sayo 《Journal of polymer science. Part A, Polymer chemistry》1989,27(12):3883-3893
Thin films were prepared on substrates, cleavage surface of KCl single crystal, and metallic copper, by reaction of 1,2,4,5-tetracyanobenzene with the substrate at various temperatures. The films were characterized by elemental analysis, IR, and UV/VIS spectroscopies. The films were observed by scanning electron microscopy. The films produced on copper at temperatures between 300 and 400°C consisted of copper octacyanophthalocyanine and its polymer with ladder structure. The ratio of polymer to monomer increased with elevating the reaction temperature. The films were composed of ribbon-like crystals. The film produced on copper above 450°C was composed of an amorphous and continuous layer of polymeric copper phthalocyanine. The film produced on KCl at temperatures between 250 and 350°C consisted of potassium octacyanophthalocyanine and its polymer with ladder structure. The film produced on KCl above 450°C was polymeric potassium phthalocyanine. Those films contained more metal content than that required stoichiometrical. 相似文献
172.
A q-difference analog of the sixth Painlevé equation is presented. It arises as the condition for preserving the connection matrix of linear q-difference equations, in close analogy with the monodromy-preserving deformation of linear differential equations. The continuous limit and special solutions in terms of q-hypergeometric functions are also discussed. 相似文献
173.
174.
175.
We continue our investigation on the newly introduced concept of the τ function [1], associated with monodromy preserving deformations of a linear differential equation . In this paper a series of τ functions parametrized by integers are introduced. Their ratios to the original τ function are then shown to be explicit rational expressions in terms of the coefficients of A(x). We point out, and follow where possible, a close analogy between the theory of τ functions and that of classical theta functions. 相似文献
176.
Sigeru Torii Kenji Uneyama Michio Ono Hiromitsu Tazawa Setsuo Matsunami 《Tetrahedron letters》1979,20(48):4661-4662
A regioselective ω-epoxidation of polyisoprenoids has been realized by the sodium bromide promoted electrochemical oxidation in a mixed solvent (MeCN-THF-H2O). 相似文献
177.
178.
Ayumi Hirano-Iwata Michio Niwano Masao Sugawara 《Trends in analytical chemistry : TRAC》2008,27(6):512-520
We describe the current status of techniques for preparing planar lipid bilayers, the fusion of sensory elements and the design of bilayer interfaces for analytical applications. Advances in bilayer fabrication have allowed preparation of lipid bilayers with membrane resistance of >1 GΩ (“gigaseal”) in flow, microfluidic and array formats, which have enabled single-channel and multi-channel recording. Not only biological but also engineered channels have been adopted as sensory elements for lipid-bilayer-based biosensors. Synthetic and inorganic channels are also emerging for designing membranes for lipid-bilayer sensors. We discuss the potential of lipid bilayers containing biological, engineered or synthetic channels for the design of biosensors, including drug-screening biosensors. 相似文献
179.
180.
Oikawa H Fujiyoshi S Dewa T Nango M Matsushita M 《Journal of the American Chemical Society》2008,130(14):4580-4581
The fluorescence excitation spectrum of a single chromophore molecule in a photosynthetic pigment-protein complex is known to change in time at liquid helium temperature. The spectral change reflects a conformational change of the protein to which the chromophore binds. This work follows the temporal behavior of the spectrum of a single chromophore in the temperature range between 5 adn 18 K. The temperature dependence reveals two types of conformational change of the protein, i.e., thermally activated motions over a potential barrier of ca. 0.1 kJ/mol and temperature-independent motions of tunneling of a proton. 相似文献