全文获取类型
收费全文 | 2043篇 |
免费 | 29篇 |
国内免费 | 8篇 |
专业分类
化学 | 1471篇 |
晶体学 | 24篇 |
力学 | 27篇 |
数学 | 151篇 |
物理学 | 407篇 |
出版年
2023年 | 10篇 |
2022年 | 9篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 23篇 |
2018年 | 19篇 |
2017年 | 11篇 |
2016年 | 35篇 |
2015年 | 27篇 |
2014年 | 36篇 |
2013年 | 78篇 |
2012年 | 88篇 |
2011年 | 109篇 |
2010年 | 61篇 |
2009年 | 59篇 |
2008年 | 125篇 |
2007年 | 129篇 |
2006年 | 151篇 |
2005年 | 144篇 |
2004年 | 114篇 |
2003年 | 88篇 |
2002年 | 87篇 |
2001年 | 41篇 |
2000年 | 39篇 |
1999年 | 33篇 |
1998年 | 20篇 |
1997年 | 20篇 |
1996年 | 28篇 |
1995年 | 34篇 |
1994年 | 30篇 |
1993年 | 18篇 |
1992年 | 29篇 |
1991年 | 19篇 |
1990年 | 27篇 |
1989年 | 18篇 |
1988年 | 20篇 |
1987年 | 21篇 |
1986年 | 15篇 |
1985年 | 16篇 |
1984年 | 20篇 |
1983年 | 8篇 |
1982年 | 17篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1978年 | 26篇 |
1977年 | 21篇 |
1976年 | 16篇 |
1974年 | 14篇 |
1972年 | 8篇 |
排序方式: 共有2080条查询结果,搜索用时 15 毫秒
1.
Sayaka Wada Kazuhiko Fujiwara Hideaki Monjushiro Hitoshi Watarai 《Analytical sciences》2004,20(11):1489-1491
The direct measurement of the circular dichroism (CD) spectra of liquid/liquid interface has been achieved for the first time by the centrifugal liquid membrane (CLM) method combined with a conventional CD spectropolarimetry. In the sample chamber of the CD spectropolarimeter, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at ca. 7000 rpm to generate a two-phase liquid membrane with a high specific interfacial area. The CD spectra of the J-aggregate of protonated 5,10,15,20-tetraphenylporphyrin formed at the toluene/sulfuric acid interface in the rotating cell have been measured. The results demonstrated the novelty and advantages of this method. 相似文献
2.
Modular and quasimodular solutions of a specific second order differential equation in the upper-half plane, which originates from a study of supersingular j-invariants in the first author's work with Don Zagier, are given explicitly. Positivity of Fourier coefficients of some of the solutions as well as a characterization of the differential equation are also discussed. 相似文献
3.
4.
5.
6.
It is shown that if in a simple graph G of order n the sum of degrees of any three pairwise non-adjacent vertices is at least n, then there are two cycles (or one cycle and an edge or a vertex) of GF that contain all the vertices. © 1995 John Wiley & Sons, Inc. 相似文献
7.
A side-chain liquid crystalline polysiloxane derivative possessing mesogens was synthesized. The mesogens included a large dielectrically-anisotropic moiety. Phase transition behaviour was investigated and the electrorheological (ER) effect of the polymer considered. No ER effect was observed in non-sheared polysiloxane derivative because of its high inherent viscosity. However, a large ER effect was observed after pre-shearing. Pre-shearing, i.e. shearing with a high shear rate before the measurements, arranges the terminal mesogens in the shearing direction. Furthermore, a dilution of the sample led to a larger ER effect exceeding 10 000 Pa. We thus were able to demonstrate a new approach for the appearance of the ER effect. 相似文献
8.
Hideaki Ishikawa 《Archiv der Mathematik》2002,79(6):439-448
In this paper we introduce a certain sum by using Dirichlet characters. We investigate the Riesz mean of the sum using the
analytic properties of the MultipleL-function systematically.
Eine überarbeitete Fassung ging am 6. 8. 2001 ein 相似文献
9.
D. Kaneko T. Narita J. P. Gong Y. Osada J. Ando K. Yamamoto S. Ohnishi V. V. Yaminsky 《Journal of Polymer Science.Polymer Physics》2003,41(22):2808-2815
The effect of the shear flow on the thickness change of a polyelectrolyte membrane grafted onto a glass substrate was directly investigated with a flow cell combined with a confocal laser scanning microscope. The membrane thickness decreased proportionally to an increase in the shear stress of the flow when the shear rate exceeded a critical value of 1 s?1. The higher the ionic strength was of the fluid, the greater the thinning effect was. The correlation between the critical shear rate and the relaxation of the polymer in the gel membrane was examined. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2808–2815, 2003 相似文献
10.
In proportion to the environmental pollution problems caused by organotin compounds, the genotoxicities of tin compounds in the environments have become of interest so as to estimate their safety in recent years. In this work, isolated λ-DNA (double-strand DNA) was incubated with inorganic tin(II) and tin(IV) and five organotin compounds [n-butyltin trichloride, di(n-butyltin) dichloride, methyltin trichloride, dimethyltin dichloride and trimethyltin chloride] in reaction systems both with and without hydrogen peroxide (H2O2) content. The tin compounds tested in this study did not induce DNA breakage in the absence of hydrogen peroxide. Divalent inorganic tin (SnCl2) and tetravalent inorganic tin (SnCl4) caused DNA breakage in the presence of hydrogen peroxide (10 mM), and the DNA damage activity of inorganic tin was much more potent in divalent inorganic tin (SnCl2) than in tetravalent inorganic tin (SnCl4). Divalent inorganic tin (SnCl2) induced DNA breakage in a concentration-dependent fashion at concentrations greater than 0.1 mM of SnCl2 in the presence of hydrogen peroxide (10 mM). DNA breakage was not caused by n-butyltin compounds and methyltin compounds either in the presence or in the absence of hydrogen peroxide. 相似文献