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941.
942.
Optics and Spectroscopy - The conditions for obtaining 20% efficiency of a single-wavelength mode-locked carbon monoxide (CO) laser for intracavity irradiation of a substance with a small... 相似文献
943.
Nanosized Ni particles with an average diameter of about 8 nm were prepared by reducing of NiCl 2 with sodium borohydride (NaBH 4 ) in aqueous solution. By moderate annealing in protective atmosphere, the composite grew up to be 15-20 nm particles. Both of the as-prepared and annealed Ni particles were coated by a layer of manganese oxide via decomposition reaction in aqueous KMnO4 solution. Hysteresis loops of as-prepared samples show a large increase in the magnetization with decreasing temperature and an unsaturated component at high magnetic field. In contrast, the ferromagnetic characteristics of annealed one are much stronger with large magnetization and coercivity. The thermomagnetic curves verified the coexistence of ferromagnetic Ni and antiferromangetic Mn oxide phases. But there exists no exchange bias behavior in the samples, even though the interface structure between the ferromagnetic Ni core and the antiferromagnetic manganese oxides has been distinctly formed. The absence of exchange bias probably originates from the weak ferromagnetic characteristic of Ni cores. 相似文献
944.
945.
946.
947.
In this paper, one-parameter families of integer translates of the Gaussian and Lorentz functions are studied. For a Lorentz function, we obtain formulas for the coefficients of the series defining node functions and show that the limit value of node functions is given by a sample function. For systems of translates generated by the Gaussian and Lorentz functions as well as by the node functions related to them, we obtain explicit expressions for the Riesz constants and study the parameter-dependent behavior of these constants. While proving some of the results of this paper, we establish the monotonicity of a special ratio of two Jacobi theta functions, a fact which is of interest in itself. 相似文献
948.
T. M. Roshchina N. K. Shoniya O. Ya. Tayakina O. P. Tkachenko L. M. Kustov F. Bernardoni A. Y. Fadeev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(3):437-446
The role of the grafting density of monofunctional polyfluoroalkylsilanes of the C
n
F2n − 1(CH2)
m
Si(CH3)2Cl general formula (where n = 3, 4, and 6; and m = 2 and 3) and their composition in intermolecular interactions of the molecules of saturated and aromatic hydrocarbons with
a surface of chemically modified silica is studied by means of IR spectroscopy and adsorption-static and gas chromatography.
It is shown that the higher the concentration and the shorter the length of the grafted chain, the greater (by a factor of
2 to 25) the drop in the adsorption values of hydrocarbons as a result of modifications, due to an increase in the degree
of oleophobization of surface upon the formation of polyorganofluorine coatings. The high specificity of the surface with
respect to benzene, which is due to the active participation of the polar fragment of a grafted chain in adsorption process,
is related to the features of a relatively low-density sample with a concentration of grafted perfluorobutyl groups of 1.7
nm−2. It is shown that the thermodestruction of polyfluoroalkyl silica remains virtually unobserved upon heating to 523 K in an
argon flow. 相似文献
949.
950.
Russian Journal of Organic Chemistry - 相似文献