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71.
Andriy Yurachkivsky 《Acta Appl Math》2003,79(1-2):157-164
A criterion for relative compactness of a sequence of measure-valued processes is proved and exemplified. 相似文献
72.
V. A. Gladkaya Z. V. Levitskaya A. S. Shalamai L. S. Usenko T. A. Dashevskaya 《Chemistry of Natural Compounds》1990,25(4):488-492
Using selective 3,5-O-tetraisopropyldisiloxane protection, N-acyl-2-O-methyl derivatives of cytidine and guanosine and of 2-O-tetrahydropyranyl-N1-methylguanosine have been synthesized. It has been shown that the spatial screening of the amino groups by the neighboring methyl substituents in N1-methylguanosine leads to its inactivation in acylation, tetrahydropyranylation, and tritylation reactions.Institute of Molecular Biology and Genetics, Ukranian SSR Academy of Sciences, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 568–573, July–August, 1989. 相似文献
73.
Imai T Hiraoka R Kovalenko A Hirata F 《Journal of the American Chemical Society》2005,127(44):15334-15335
Four water molecules confined in a small cavity of hen egg-white lysozyme were detected by means of the three-dimensional (3D) RISM theory, a statistical-mechanical theory of molecular solutions. This is the first theoretical realization of confined molecules in a protein without making nonsense tricks, such as placing the molecules in the space a priori. Possible impacts which the result may have on biochemistry and biophysics, including the molecular recognition, enzymatic reactions, etc., are discussed. 相似文献
74.
75.
76.
Höfft O Borodin A Kahnert U Kempter V Dang LX Jungwirth P 《The journal of physical chemistry. B》2006,110(24):11971-11976
Surface segregation of iodide, but not of fluoride or cesium ions, is observed by a combination of metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy (UPS(HeI)) of amorphous solid water exposed to CsI or CsF vapor. The same surface ionic behavior is also derived from molecular dynamics (MD) simulations of the corresponding aqueous salt solutions. The MIES results show the propensity of iodide, but not fluoride, for the surface of the amorphous solid water film, providing thus strong evidence for the suggested presence of heavier halides (iodide, bromide, and to a lesser extent chloride) at the topmost layer of aqueous surfaces. In contrast, no appreciable surface segregation of ions is observed in methanol, neither in the experiment nor in the simulation. Furthermore, the present results indicate that, as far as the thermodynamic aspects of solvation of alkali halides are concerned, amorphous solid water and methanol surfaces behave similarly as surfaces of the corresponding liquids. 相似文献
77.
We address the applicability of the continuous-variables quantum key distribution in the realistic conditions of noisy preparation,
channel loss and detection noise and investigate the possibility to increase its tolerance to the state preparation noise.
The two types of preparation noise, either phase-sensitive or phase-insensitive excess noise, are considered in the assumption
of optimal attacks performed by an eavesdropper within the setup based on the entangled source and either homodyne or heterodyne
measurements. We show that preparation noise is destructive for the secure channel upon even low noise variances in the conditions
of channel loss, while detection noise just decreases the key rate. We propose the method of sender-side attenuation to suppress
the preparation noise in the entanglements-based scheme and show that it enables the secure key transmission upon arbitrary
high preparation noise of both types and any pure channel loss against both individual and collective attacks. 相似文献
78.
M. M. Chugunova I. A. Kamenskikh V. V. Mikhailin S. A. Usenko 《Optics and Spectroscopy》2010,109(6):887-892
We present the results of studying the luminescence properties of transparent ceramics Y3Al5O12:Yb obtained by the vacuum sintering and nanocrystalline technology. In the course of research, we measured the luminescence
and luminescence excitation spectra, as well as the temperature and kinetic behavior of luminescence. Our results are analyzed
in comparison with the characteristics of corresponding single crystals. We revealed that processes of generation and relaxation
of electronic excitations that occur in ceramics, in particular, in the charge transfer state, are similar to processes occurring
in crystals. The behavior of two charge-transfer luminescence bands at 340 and 490 nm is studied. In the range 300–600 nm,
we revealed a broad emission band of radiation of other type, which is also observed in spectra of undoped ceramics. This
broad band is attributed to F+ centers. Emission and excitation spectra of charge transfer luminescence at a maximum of the temperature dependence of 100
K are measured for the first time. We found that, upon excitation in the charge transfer band, luminescence in ceramics is
more intense than in single crystals with similar concentrations of Yb and has a higher quenching temperature. 相似文献
79.
80.
We present the results for thermal expansion coefficients of Sn2P2S6 crystals determined both in the crystallographic system and the system based on eigenvectors of thermal expansion tensor. Peculiarities of temperature evolution of the indicative surface of thermal expansion tensor for Sn2P2S6 are discussed, including the region of their ferroelectric phase transition. 相似文献