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21.
V. K. Ignatovich 《Theoretical and Mathematical Physics》2010,163(1):517-530
In the perturbation theory framework, we compute the cross section of scattering by a magnetic nanocylinder and a helicoid
arbitrarily oriented in an external magnetic field. We are the first to obtain the matrix Green’s function for two media with
an interface and noncollinear magnetic fields on the two sides of the interface. We show how to compute scattering by magnetic
inclusions in one of the media. 相似文献
22.
We describe a general scheme for solving nonconvex optimization problems, where in each iteration the nonconvex feasible set
is approximated by an inner convex approximation. The latter is defined using an upper bound on the nonconvex constraint functions.
Under appropriate conditions, a monotone convergence to a KKT point is established. The scheme is applied to truss topology
design (TTD) problems, where the nonconvex constraints are associated with bounds on displacements and stresses. It is shown
that the approximate convex problem solved at each inner iteration can be cast as a conic quadratic programming problem, hence
large scale TTD problems can be efficiently solved by the proposed method. 相似文献
23.
S. V. Kozhevnikov V. K. Ignatovich A. V. Petrenko F. Radu 《Journal of Experimental and Theoretical Physics》2016,123(6):950-956
We report on the results of the experimental investigation of the spectral width of neutron resonances in planar waveguides using the time-of-flight method and recording the microbeam emerging from the waveguide end. Experimental data are compared with the results of theoretical calculations. 相似文献
24.
We study the uncertain dichotomous choice model. In this model a group of decision makers is required to select one of two alternatives. The applications of this model are relevant to a wide variety of areas, such as medicine, management and banking. The decision rule may be the simple majority rule; however, it is also possible to assign more weight to the opinion of members known to be more qualified. The extreme example of such a rule is the expert decision rule. We are concerned with the probability of the expert rule to be optimal. Our purpose is to investigate the behaviour of this probability as a function of the group size for several rather general types of distributions. One such family of distributions is that where the density function of the correctness probability is a polynomial (on the interval [1/2,1]). Our main result is an explicit formula for the probability in question. This contains formerly known results as very special cases. 相似文献
25.
高岭土(Kaolinite)和蒙脱土(Montromollite)等粘土,被广泛用作添加剂来改善聚合物的耐热性能。文章用各种先进技术对高岭土与蒙脱土的形态、组成和结构进行表征比较。电子透射电镜及电子探针(TEM/EDX)结果显示高岭土较蒙脱土有较大的粒径和较小的硅铝比,TEM还显示出这些粘土是由片层粒子堆积而成。热重分析(TGA)的结果表明蒙脱土由于失去吸附水从60 ℃升温至90 ℃失重明显(约7%),而高岭土在此温度下几乎不失水。高岭土脱除结构羟基官能团脱水失重的温度大约在510 ℃,低于蒙脱土的670 ℃。室温下光声傅里叶变换(PAS-FTIR)红外光谱显示蒙脱土在羟基吸收区有较强的吸附水的吸收,1 650 cm-1处孤立的弱吸收谱带可给予左证。变温红外和TGA的结果显示,片层硅酸盐表面的结构羟基从100~500 ℃非常稳定,它可以和异氰酸酯基团(NCO)封端的预聚物反应形成热固性PU/PLS复合聚合物。 相似文献
26.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 6, pp. 938–944, December, 1989. 相似文献
27.
Zh.?V.?Ignatovich A.?L.?Ermolinskaya E.?V.?KorolevaEmail author A.?N.?Eremin 《Russian Journal of Organic Chemistry》2018,54(6):943-944
A preparative procedure has been proposed for the reduction of substituted nitroarenes with hydrazine hydrate in the presence of a nanocatalyst based on cobalt–nickel nanoparticles, which ensured selective formation of the corresponding anilines in 78–80% yield in 20–45 min. 相似文献
28.
E. Lukevics I. Shmukste I. Iovel' L. Ignatovich 《Chemistry of Heterocyclic Compounds》1998,34(6):734-736
A series of 1-(pyridylmethoxy)silatranes was obtained by the dehydrocondensation of pyridinemethanols with 1-hydrosilatrane catalyzed by potassiumtert-butylate. 相似文献
29.
Clay such as kaolinite, is commonly used as an additive to modify the thermal properties of polymer. In this paper, the morphology, composition, shape and structure of kaolinite was characterized by various advanced techniques. The TEM/ EDX data showed that the kaolinite had a larger particle size and a Si/Al ratio of 1.8. The individual particle of kaolinite was a single crystalline. TEM also showed that these particles were always stacked together due to the presence of electrostatic cohesive energy and hydrogen bond between plaletes. The PAS-FTIR spectra showed that no absorbance of hydroxyl group for hydration water in hydrogen bond region or at 1650cm-1 was observed at room temperature. It meant a little ability to adsorb water for kaolinite particle. Kaolinite clay also showed no change for its PAS-FTIR spectra with increasing temperature. The TGA results revealed that kaolinite almost doesn′t lose weight at 60℃ due to loss of dehydration of absorbed water, however, it will decomposed around 510℃ and lose its hydroxyl functional group in the form of water (dehydroxylation). The result is consistent with that of PAS-FTIR analysis. This suggests that the structural hydroxyl group on the surface of individual kaolinite clay particle is very stable below 500℃, and the kaolinite composed polymer could be got by the reaction of its stable structural hydroxyl group with isocynate group of polyurethane prepolymer. 相似文献
30.
Ignatovich Zh. V. Ermolinskaya A. L. Ol’khovik V. K. Matveenko Yu. V. Koroleva E. V. 《Russian Journal of Organic Chemistry》2019,55(4):487-492
Russian Journal of Organic Chemistry - New carboxamides and sulfonamides containing alkyl and heterocyclic fragments were synthesized on the basis of 2-arylaminopyrimidine derivatives,... 相似文献