全文获取类型
收费全文 | 139篇 |
免费 | 0篇 |
专业分类
化学 | 39篇 |
力学 | 1篇 |
数学 | 11篇 |
物理学 | 88篇 |
出版年
2015年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1942年 | 2篇 |
1886年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 15 毫秒
101.
RESONANCE RAMAN STUDIES OF BACTERIORHODOPSIN ANALOGUES 总被引:1,自引:0,他引:1
R. Schiffmiller R. H. Callender W. H. Waddell † R. Govindjee T. G. Ebrey H. Kakitani † B. Honig K. Nakanishi 《Photochemistry and photobiology》1985,41(5):563-567
Abstract— We present the results of resonance Raman measurements on a series of bacteriorhodopsin (bR) analogues formed from synthetic retinals which have replaced the native chromophore in the active site. Specifically, 5,6-dihydro-bR, 13-desmethyl-bR, 10-methyl-bR, 14-methyl-bR, and 10.14-dimethyl-bR have been studied. All five analogues bind and form Schiff base retinal-apoprotein linkages. While the Schiff base linkages of 5,6-dihydro-bR, 13-desmethyl-bR, and 10-methyl-bR are protonated, like the native chromophore, the 14-methyl-bR, and 10,14-dimethyl-bR Schiff bases are unprotonated. These results suggest that the binding site of bacteriorhodopsin near the Schiff base moiety is different from that of rhodopsin. The protonated Schiff base -C=NH- stretching frequency of 5.6-dihydro-bR lies at 1660 cm-1 which is unusually high for a bacteriorhodopsin based pigment. The downward shift upon deuteration is 16 cm-1 , essentially identical to that measured for bacteriorhodopsin. This and the other analogue results strongly reinforce our previous arguments that the Schiff base stretching frequency is determined in large part by two factors, the C=N force constant and the stretch interaction with C=N-H bend. On the other hand, the deuterium isotope effect is determined primarily by the stretch-bend interaction. 相似文献
102.
Aitala EM Amato S Anjos JC Appel JA Ashery D Banerjee S Bediaga I Blaylock G Bracker SB Burchat PR Burnstein RA Carter T Carvalho HS Costa I Cremaldi LM Darling C Denisenko K Fernandez A Gagnon P Gerzon S Gobel C Gounder K Granite D Halling AM Herrera G Hurvits G James C Kasper PA Kondakis N Kwan S Langs DC Leslie J Lichtenstadt J Lundberg B Manacero A MayTal-Beck S Meadows B de Mello Neto JR Milburn RH de Miranda JM Napier A Nguyen A d'Oliveira AB O'Shaughnessy K Peng KC Perera LP Purohit MV 《Physical review letters》1996,76(3):364-367
103.
104.
105.
106.
Interfacing functional proteins with solid supports for device applications is a promising route to possible applications in bio-electronics, -sensors, and -optics. Various possible applications of bacteriorhodopsin (bR) have been explored and reviewed since the discovery of bR. This tutorial review discusses bR as a medium for biomolecular optoelectronics, emphasizing ways in which it can be interfaced, especially as a thin film, solid-state current-carrying electronic element. 相似文献
107.
JM Pakarinen H Moisio S Holopainen P Vainiotalo 《Rapid communications in mass spectrometry : RCM》1999,13(14):1485-1490
2-Methoxyethanol chemical ionization of amines, carboxylic acids and amino acids has been found to produce numerous adduct ions. The most intense adduct ions for amines are [M + H](+) and [M + 77](+), for carboxylic acids [M + 27](+), [M + 59](+) and [M + 77](+), and for amino acids [M + H](+), [M + 13](+), [M + 27](+) and [M + 77](+). Either the adduct ion [M + H](+) or [M + 77](+) was the most abundant ion found for amino acids. The proton affinities of amino acids are noticed to control the formation of the [M + H](+) and [M + 77](+) ions. The relative abundance of [M + 13](+) and [M + 27](+) ions varied for different amino acids being most intense for phenylalanine and aspartic acid. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
108.
I review recent progress on the electroweak phase transition and baryogenesis, focusing on the minimal supersymmetric Standard
Model as the source of new physics. 相似文献
109.
110.
McNabb JW Balakishiyeva DN Honig A 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2007,188(2):206-215
Spin-lattice relaxation of (129)Xe nuclei in solid natural xenon has been investigated in detail over a large range of paramagnetic O(2) impurity concentrations. Direct measurements of the ground state magnetic properties of the O(2) are difficult because the ESR (electron spin resonance) lines of O(2) are rather unstructured, but NMR measurements in the liquid helium temperature region (1.4-4 K) are very sensitive to the effective magnetic moments associated with the spin 1 Zeeman levels of the O(2) molecules and to the O(2) magnetic relaxation. From these measurements, the value of the D[Sz(2)-(1/3)S(2)] spin-Hamiltonian term of the triplet spin ground state of O(2) can be determined. The temperature and magnetic field dependence of the measured paramagnetic O(2)-induced excess line width of the (129)Xe NMR signal agree well with the theoretical model with the spin-Hamiltonian D=0.19 meV (2.3 K), and with the reasonable assumption that the E[S(x)(2)-S(y)(2)] spin-Hamiltonian term is close to 0 meV. An anomalous temperature dependence between 1.4 K and 4.2K of the (129)Xe spin-lattice relaxation rate, T(1n)(-1)(T), is also accounted for by our model. Using an independent determination of the true O(2) concentration in the Xe-O(2) solid, the effective spin lattice relaxation time (which will be seen to be transition dependent) of the O(2) at 2.3 K and 0.96 T is determined to be approximately 1.4 x 10(-8)s. The experimental results, taken together with the relaxation model, suggest routes for bringing highly spin-polarized (129)Xe from the low temperature condensed phase to higher temperatures without excessive depolarization. 相似文献