全文获取类型
收费全文 | 6894篇 |
免费 | 229篇 |
国内免费 | 46篇 |
专业分类
化学 | 5085篇 |
晶体学 | 25篇 |
力学 | 213篇 |
数学 | 906篇 |
物理学 | 940篇 |
出版年
2023年 | 67篇 |
2022年 | 88篇 |
2021年 | 128篇 |
2020年 | 122篇 |
2019年 | 150篇 |
2018年 | 93篇 |
2017年 | 85篇 |
2016年 | 201篇 |
2015年 | 171篇 |
2014年 | 205篇 |
2013年 | 382篇 |
2012年 | 479篇 |
2011年 | 515篇 |
2010年 | 279篇 |
2009年 | 244篇 |
2008年 | 434篇 |
2007年 | 445篇 |
2006年 | 400篇 |
2005年 | 386篇 |
2004年 | 358篇 |
2003年 | 310篇 |
2002年 | 263篇 |
2001年 | 99篇 |
2000年 | 87篇 |
1999年 | 77篇 |
1998年 | 60篇 |
1997年 | 68篇 |
1996年 | 83篇 |
1995年 | 55篇 |
1994年 | 44篇 |
1993年 | 40篇 |
1992年 | 46篇 |
1991年 | 38篇 |
1990年 | 38篇 |
1989年 | 29篇 |
1988年 | 22篇 |
1986年 | 27篇 |
1985年 | 33篇 |
1984年 | 42篇 |
1983年 | 28篇 |
1982年 | 42篇 |
1981年 | 30篇 |
1980年 | 38篇 |
1979年 | 26篇 |
1978年 | 33篇 |
1977年 | 42篇 |
1976年 | 28篇 |
1975年 | 30篇 |
1974年 | 19篇 |
1973年 | 21篇 |
排序方式: 共有7169条查询结果,搜索用时 15 毫秒
991.
David Clarke B. H. Patrick Rivett 《The Journal of the Operational Research Society》1978,29(2):113-128
Different methods currently available for multiple criteria decision analysis, such as cost-benefit analysis and utility theory, make strong axiomatic demands. The method suggested here uses multidimensional scaling techniques, as applied to the problem of constructing geographical maps from fragmentary information, to draw maps of policies involving many attributes in such a way as to throw most preferred and least preferred policies to opposite poles. The only axiomatic demand is non-transitive indifference. An analysis suggests that the method is robust against changes in the input data. 相似文献
992.
Patrick Luquet 《Applied Acoustics》1982,15(5):377-388
A technique applicable to situations with different noise sources is developed on the basis of a series of limited data (short-term ).This technique makes acoustic monitoring of a site possible, identifying and evaluating the respective contributions of the different components of the environment studied. 相似文献
993.
Commercial glasses typically consist of many metal oxides and the surface composition of a glass article can be very different from that of its interior due to vaporization, surface migration, etc., during fabrication. At the same time the chemical make-up of the surface is extremely important in any commercial application, directly affecting the strength and durability of the product. Analytical techniques capable of examining the surface composition have been limited, however, and classical methods of chemical analysis have never been able to supply the desired information. This paper contains a review of analytical procedures that have been used for glass surface analysis and explores the potential of several recently developed techniques. These include the Electron Microprobe, Electron Spectroscopy for Chemical Analysis (ESCA), Auger Electron Spectroscopy, Ion Scattering Spectroscopy and Secondary Ion Mass Analysis. The use of Electron Spectroscopy in the study of glass compositions common to the glass fiber industry will be explored in depth. 相似文献
994.
995.
Patrick Hecking 《Physics letters. [Part B]》1981,103(6):401-404
The mean free paths for true absorption and inelastic scattering-as well as true absorption alone-of pions in symmetric nuclear matter are deduced from two sets of optical model parameters. 相似文献
996.
The existence of zeros of operators which map into a Banach space E but whose domain is the space of continuous functions on some real interval into E are considered. 相似文献
997.
The steric course of the 1–2 addition of organometallics to the (±) 2-methyl, 2-phenyl, 1-indanone mainly depends on the nature of the metal. Most strikingly opposite stereoselectivities are observed with organolithium and organomagnesium reagents. These results point out the directive effect of the adjacent phenyl group via metal-arene coordination in the transition state. 相似文献
998.
999.
1000.
Patrick H. Byrne 《Foundations of Physics》1981,11(11-12):913-932
It is well known that Albert Einstein adhered to a deterministic world view throughout his career. Nevertheless, his developments of the special and general theories of relativity prove to be incompatible with that world view. Two different forms of determinism—classical Laplacian determinism and the determinism of isolated systems—are considered. Through careful considerations of what concretely is involved in predicting future states of the entire universe, or of isolated systems, it is shown that the demands of the theories of relativity make these deterministic positions untenable. 相似文献