全文获取类型
收费全文 | 280篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
化学 | 121篇 |
晶体学 | 1篇 |
力学 | 12篇 |
数学 | 32篇 |
物理学 | 120篇 |
出版年
2018年 | 5篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 11篇 |
2009年 | 4篇 |
2008年 | 8篇 |
2007年 | 13篇 |
2006年 | 17篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1970年 | 2篇 |
1966年 | 3篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1959年 | 1篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1956年 | 2篇 |
排序方式: 共有286条查询结果,搜索用时 15 毫秒
61.
The magnetic and quadrupole hyperfine interactions in amorphous EuFe2Si2 have been measured using57Fe and151Eu Mössbauer spectroscopy. The distributions in the various parameters have been found using the Fourier coefficient method. Novel features of the results are that the Eu charge state (4f occupation number) changes between the crystalline and amorphous phases and that whereas in the crystalline phase neither Eu nor Fe is magnetic, both become so in the amorphous phase. 相似文献
62.
Wilson Michael W. Hernández Andrés S. Calvet Alain P. Hodges John C. 《Molecular diversity》1997,3(2):95-112
Two solid-supported synthesis strategies for the preparation of 3-thio-1,2,4-triazoles are described. In the first, Rink amide
resin is combined with Fmoc-protected ω-amino acids, acid hydrazides, and alkyl halides to provide diverse sets of starting
materials from which numerous triazoles may be prepared. The second employs t-alkylcarbamateresin (Boc resin) which permits
the use of additional pools of starting materials, including isothiocyanates and α- and ω-amino esters, resulting in triazoles
with patterns of functional groups that are not possible from the initial route. The combination of multiple resins and resin
attachment sites allows the preparation of a diverse library based upon the3-thio-1,2,4-triazole scaffold and avoids the pitfallof
having a single linker functionality present at the same position in all library members. General synthetic procedures and
representative products from each route are presented. A similarity analysis of representative sublibraries from each synthesis
strategy concludes that variation of the solid-phase linker chemistry and attachment site can enhance molecular diversity
of the combined triazole library.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
63.
J. A. Hodges P. Imbert G. Jéhanno J. B. Marimon Da Cunha J. P. Sanchez 《Hyperfine Interactions》1988,42(1-4):1225-1226
For the high Tc compound YbBa2Cu3O7−x, Mossbauer absorption measurements show that magnetic ordering occurs within the Yb3+ sublattice at 0.35K (μsat=1.7μB). For ErBa2Cu3O7−x the Er3+ sublattice orders at 0.7K (μsat=4μB). Measurements on57Fe diluted into YBa2Cu3O7−x shows that no ordered magnetic moments exist within the Cu sublattices down to at least 4.2K.
Instituto de Fisica, Porto-Alegre, Brasil (supported by CNPq) 相似文献
64.
The baroclinic stability of a family of two time‐level, semi‐implicit schemes for the 3D hydrostatic, Boussinesq Navier–Stokes equations (i.e. the shallow water equations), which originate from the TRIM model of Casulli and Cheng (Int. J. Numer. Methods Fluids 1992; 15 :629–648), is examined in a simple 2D horizontal–vertical domain. It is demonstrated that existing mass‐conservative low‐dissipation semi‐implicit methods, which are unconditionally stable in the inviscid limit for barotropic flows, are unstable in the same limit for baroclinic flows. Such methods can be made baroclinically stable when the integrated continuity equation is discretized with a barotropically dissipative backwards Euler scheme. A general family of two‐step predictor‐corrector schemes is proposed that have better theoretical characteristics than existing single‐step schemes. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
65.
66.
67.
68.
69.
70.
The present study extends the utility of reversed-phase high-performance liquid chromatography (RP-HPLC) to monitor folding and stability of de novo designed synthetic two-stranded alpha-helical coiled-coils. Thus, we have compared the effect of temperature on the RP-HPLC retention behaviour of both oxidized (two identical five-heptad alpha-helical peptides linked by a disulfide bridge) and reduced coiled-coil analogues with various amino acids substituted into the hydrophobic core of the coiled-coil. We were able to correlate the RP-HPLC retention behaviour of the oxidized analogues over the temperature range of 10 to 80 degrees C with the stability of the analogues as determined by conventional thermal and chemical denaturation approaches. In addition, the contribution of a disulfide bridge to coiled-coil stability was highlighted by comparing the elution behaviour of the oxidized and reduced analogues. Overall, we demonstrate the excellent potential of "temperature profiling" by RP-HPLC to monitor differences in oligomerization state and protein stability. 相似文献