全文获取类型
收费全文 | 139篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 76篇 |
晶体学 | 3篇 |
力学 | 2篇 |
数学 | 40篇 |
物理学 | 19篇 |
出版年
2020年 | 3篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 7篇 |
2007年 | 2篇 |
2006年 | 11篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有140条查询结果,搜索用时 0 毫秒
51.
A graph is said to be detour‐saturated if the addition of any edge results in an increased greatest path length. In this paper, we add to the relatively small amount that is known about detour‐saturated graphs. Our main result is a determination of all connected detour‐saturated graphs with exactly one cycle. (The family of detour‐saturated trees was found by Kászonyi and Tuza 7 .) We also show that the smallest detour‐saturated graph of girth 5 is the graph obtainable from the Petersen graph by splitting one of its vertices into three, each of degree 1. © 2005 Wiley Periodicals, Inc. J Graph Theory 相似文献
52.
Philip W. Westerman Sarath P. Gunasekera M. Uvais S. Sultanbawa Rymantas Kazlauskas 《Magnetic resonance in chemistry : MRC》1977,9(11):631-636
The 13C n.m.r. spectra of 36 naturally occurring xanthones are reported and all chemical shifts assigned. The shifts in substituted xanthones can be predicted from substituent effects evaluated for simple derivatives. The agreement between calculated and observed shifts decreases as the extent of substitution in the xanthone increases. 相似文献
53.
54.
55.
Computer simulated experiments are reported which demonstrate that the rate of mutual neutralization in an ambient gas may be greatly enhanced by the bound ion pairs formed. The contributing energy range (expressed in units of kθ where θ is the temperature) is remarkably wide. 相似文献
56.
Brady LJ Valliere-Douglass J Martinez T Balland A 《Journal of the American Society for Mass Spectrometry》2008,19(4):502-509
Mass analysis of recombinant protein therapeutics is an important assay for product characterization. Intact mass analysis is used to provide confirmation of proper translation of the DNA sequence and to detect the presence of post-translational modifications such as amino acid processing and glycosylation. We present here a method for the rapid mass analysis of antibodies using a polyhydroxyethyl aspartamide column operated in size-exclusion mode and coupled with ESI-MS. This method allows extremely efficient desalting of proteins under acidic conditions that are optimal for subsequent mass analysis using standard ESI conditions. Furthermore, this technique is significantly faster and more sensitive than rpHPLC methods, typically considered the standard chromatography approach for mass analysis of proteins. This method is flexible and robust, and should prove useful for applications where a combination of speed and sensitivity are required. 相似文献
57.
Lawrence J Focsan AL Konovalova TA Molnar P Deli J Bowman MK Kispert LD 《The journal of physical chemistry. B》2008,112(17):5449-5457
Carotenoid (Car) radical intermediates formed upon catalytic or photooxidation of lutein (I), 7'-apo-7',7'-dicyano-beta-carotene (II), and lycopene (III) inside Cu(II)-MCM-41 molecular sieves were studied by pulsed electron nuclear double resonance (ENDOR) spectroscopies. The Davies and Mims ENDOR spectra (15-20 K) were simulated using the hyperfine coupling constants predicted by density functional theory (DFT) calculations. The DFT calculations revealed that upon chemical oxidation, carotenoid radical cations (Car*+) are formed, whereas carotenoid neutral radicals (#Car*) are produced by proton loss (indicated by #) from the radical cation. This loss is to first order independent of polarity or hydrogen bonding for carotenoids I, II, or III inside Cu(II)-MCM-41 molecular sieves. 相似文献
58.
This paper describes the analysis of a novel modification identified on the light chain of a recombinant IgG2 antibody. This modification, a +162 Da adduct, suggestive of a single hexose addition, was observed by mass analysis of the reduced molecule. The modification was located on residue serine 66 of the light chain by investigation with LC-MS peptide mapping, mass spectrometry and N-terminal sequencing techniques. Location of the adduct on serine pointed the investigation toward O-linked glycosylation. Identification of the hexose residue was deduced from its elimination by action of alpha-mannosidase, providing evidence for the presence of an O-mannosylated light chain. This type of modification in the glycosylation profile of antibodies, to our knowledge, has not been reported for human IgG molecules. 相似文献
59.
Dragomir Z. Dokovic Lowell G. Sweet 《Proceedings of the American Mathematical Society》1999,127(11):3169-3174
A (non-associative) algebra , over a field , is called homogeneous if its automorphism group permutes transitively the one dimensional subspaces of . Suppose is a nontrivial finite dimensional homogeneous algebra over an infinite field. Then we prove that for all in , and so for all .
60.
Yang Xi Beckwith Andrew W. Miller John H. Wood Lowell T. 《Central European Journal of Physics》2004,2(4):636-644
The charges in live cells interact with or produce electric fields, which results in enormous dielectric responses, flexoelectricity,
and related phenomena. Here we report on a contraction of Schizosaccharomyces pombe (fission yeast) cells induced by magnetic fields, as observed using a phase-sensitive projection imaging technique. Unlike electric fields, magnetic fields only act
on moving charges. The observed behavior is therefore quite remarkable, and may result from a contractile Lorentz force acting
on diamagnetic screening currents. This would indicate extremely high intracellular charge mobilities. Besides, we observed
a large electro-optic response from fission yeast cells. 相似文献