全文获取类型
收费全文 | 94篇 |
免费 | 1篇 |
专业分类
化学 | 21篇 |
晶体学 | 1篇 |
力学 | 9篇 |
数学 | 12篇 |
物理学 | 52篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1976年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有95条查询结果,搜索用时 46 毫秒
1.
Eneyskaya EV Ivanen DR Shabalin KA Kulminskaya AA Backinowsky LV Brumer Iii H Neustroev KN 《Organic & biomolecular chemistry》2005,3(1):146-151
Transglycosylation catalyzed by a beta-D-xylosidase from Aspergillus sp. was used to synthesize a set of 4-methylumbelliferyl (MU) beta-1-->4-D-xylooligosides having the common structure [beta-D-Xyl-(1-->4)]2-5-beta-D-Xyl-MU. MU xylobioside synthesized chemically by the condensation of protected MU beta-D-xylopyranoside with ethyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside was used as a substrate for transglycosylation with the beta-D-xylosidase from Aspergillus sp. to produce higher MU xylooligosides. The structures of oligosaccharides obtained were established by 1H and 13C NMR spectroscopy and electrospray tandem mass spectrometry. MU beta-D-xylooligosides synthesized were tested as fluorogenic substrates for the GH-10 family beta-D-xylanase from Aspergillus orizae and the GH-11 family beta-D-xylanase I from Trichoderma reesei. Both xylanases released the aglycone from MU xylobioside and the corresponding trioside. With substrates having d.p. 4 and 5, the enzymes manifested endolytic activities, splitting off MU, MUX, and MUX2 primarily. 相似文献
2.
3.
DETECTION OF DNA-PSORALEN PHOTOADDUCTS in situ 总被引:1,自引:0,他引:1
ZOFIA ZAREBSKA† MARIA JARZABEK-CHORZELSKA ‡ GENOWEFA RZSA WIESLAW GLISKI MARIA PAWIKA TADEUSZ CHORZELSKI STEFANIA JABLOKA 《Photochemistry and photobiology》1984,39(3):307-312
Abstract— An immunological method, with the use of specific immune serum, has been developed for detection of 8-methoxypsoralen (8-MOP) photoadducts to DNA, formed in situ in cell nuclei, after combined treatment with 8MOP and UV-A irradiation (Zarçbska et al. , 1978). Lymphocytes fixed on slides or in suspension, and cryostat sections of different mammalian tissues, served as antigenic substrate, after treatment with 8-MOP and UV-A in vitro. Specific fluorescence in these substrates was detected in the nuclei after treatment with 30 ˜ 140 kJ/m2 UV-A in the presence of 0.1-0.3 μg/cm2 8-MOP. PHA-stimulated-lymphocytes appeared to be the most sensitive substrate.
However, hairless mice treated with high doses of UV-A in vivo , 70 ˜ 360 kJ/m2 did not reveal a specific fluorescence of epidermal nuclei, unless a high local concentration of 8-MOP was attained.
The apparent discrepancy in the level of photoadduct detection between the in vitro and in vivo treated specimens was explained by the low number of DNA-8-MOP-photoadducts formed in vivo under these experimental conditions. The relevance of these findings to the role of DNA-8-MOP-photoadducts formed during PUVA photochemotherapy is discussed. 相似文献
However, hairless mice treated with high doses of UV-A in vivo , 70 ˜ 360 kJ/m
The apparent discrepancy in the level of photoadduct detection between the in vitro and in vivo treated specimens was explained by the low number of DNA-8-MOP-photoadducts formed in vivo under these experimental conditions. The relevance of these findings to the role of DNA-8-MOP-photoadducts formed during PUVA photochemotherapy is discussed. 相似文献
4.
5.
Treatment of glycosyl halides with NaN3 in aqueous acetone or acetonitrile is a convenient method for the stereoselective synthesis of 1,2-trans-per-O-acetyl-glycosyl azides. 相似文献
6.
A spin-reorientational phase transition in the basal plane, which was experimentally observed earlier, is explained in terms of a model in which the crystalline Fe-ion matrix is considered as a continuum, while dopant Dy ions are treated as quasi-Ising ions. The transition is established to be due to the Fe-subsystem anisotropy competing with that of the rare-earth subsystem. 相似文献
7.
V. G. Dudnikov A. L. Shabalin 《Journal of Applied Mechanics and Technical Physics》1990,31(2):163-169
Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 3–10, March–April, 1990. 相似文献
8.
We consider the Hilbert boundary-value problem with a finite index for the case, when the coefficients in the boundary condition have two infinite sequences of discontinuity points of the first kind. We obtain a formula for the general solution and study the solvability issues. 相似文献
9.
We obtain a solution to the Hilbert boundary value problem in the theory of analytic functions on the half-plane in the case that the coefficients of the boundary condition have countably many discontinuity points of the first kind. We elaborate the two substantially different situations: the series consisting of the jumps of the argument of the coefficient function and the increments of its continuous part converges and this series diverges. Accordingly, Hilbert problems with finite and infinite indices result. We derive formulas for the general solution and investigate the pictures of solvability of these problems. 相似文献
10.
I. G. Shabalin A. E. Serov O. E. Skirgello V. I. Timofeev V. R. Samygina V. O. Popov V. I. Tishkov I. P. Kuranova 《Crystallography Reports》2010,55(5):806-810
Crystals of high-purity recombinant NAD+-dependent formate dehydrogenase from the higher plant Arabidopsis thaliana (AraFDH) were grown in microgravity in the Modul’-1 protein crystallization apparatus on the International Space Station. The space-grown crystals have larger sizes than those grown on Earth. X-ray diffraction data suitable for determining the three-dimensional structure were collected from the space-grown crystals to a resolution of 1.22 Å using an X-ray synchrotron source. The crystals belong to sp. gr. P43212; the unit-cell parameters are a = b = 107.865 Å, c = 71.180 Å, α = β = γ = 90°. 相似文献