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131.
Controllable accumulation of copper(II) oxide in porous glass was carried out by repeated impregnation of the carrier by Cu(NO3)2 aqueous solutions with subsequent thermal decomposition of the salt. The results of measuring electric conductivity of a series of modified plates in combination with the data on the optical and X-ray electron spectroscopy make it possible to characterize two trends in the oxide distribution on a silica surface. In the case of its cyclic accumulation by small portions, a two-dimensional structure of monolayer filling the surface is presumably formed in a narrow range of CuO concentration, whereas the increase in the ??step?? of the accumulation gives rise to the formation and growth of island oxide particles. 相似文献
132.
Tests currently used for condoms are surrogates for the challenges they face in use. The tests involve looking for holes and slow stretching to break. This article describes a test that adds cyclic strain to a level well below breakage, and examines the differences among brands and types of condom. It is shown that there are very significant differences in resistance to cyclic straining. Such a test could be developed into a standard test for condom acceptability. 相似文献
133.
Pak V. Kh. Ghyngazov S. A. Miklin M. B. Ananiev V. A. Lysenko E. N. Kupchishin A. I. 《Russian Physics Journal》2019,62(5):756-762
Russian Physics Journal - Using the EPR method, an identification of paramagnetic centers formed in TlNO3 under γ-irradiation at 77 and 300 K is performed. Their spectral characteristics,... 相似文献
134.
2-Methylthio-4H-4-chromenone which is key intermediate for the synthesis of 2-methylsulfonyl-4H-4-chromenone, equivalent to 2-halo-4H-4-chromenone, was very easily and efficiently synthesized from 2'-hydroxyacetophenone analogues via ketene dithioacetal in the one-pot reaction. 相似文献
135.
136.
This is the first of two papers, in which we prove some properties of the Webster scalar curvature flow. More precisely, we establish the long-time existence, Lp convergence and the blow-up analysis for the solution of the flow. As a by-product, we prove the convergence of the CR Yamabe flow on the CR sphere. The results in this paper will be used to prove a result of prescribing Webster scalar curvature on the CR sphere, which is the main result of the second paper. 相似文献
137.
In 1995, Beauquier, Nivat, Rémila, and Robson showed that tiling of general regions with two bars is NP-complete, except for a few trivial special cases. In a different direction, in 2005, Rémila showed that for simply connected regions by two rectangles, the tileability can be solved in quadratic time (in the area). We prove that there is a finite set of at most 106 rectangles for which the tileability problem of simply connected regions is NP-complete, closing the gap between positive and negative results in the field. We also prove that counting such rectangular tilings is #P-complete, a first result of this kind. 相似文献
138.
Selective growth of ZnO nanorods has been successfully performed on the patterned Au/Ti metal electrode regions on a glass substrate by using a seeded thermo-electrochemical method in an acidic growth solution. The selective growth mechanism of the thermo-electrochemical method was proposed by using a series of chemical reactions for the first time. The thermo-electrochemical selective ZnO growth was performed on the cathode electrode at a temperature below 90 °C. A ZnO seed layer was precoated and selectively etched away from the non-metal regions in order to create the patterned selective nucleation sites on which the precursors are transferred and crystallized into ZnO nanorods. Both the dimensions and the placements of the ZnO nanorods have been simultaneously controlled. Energy dispersive X-ray spectrometry showed that the selectively grown ZnO nanorods consist of only Zn and O, indicating that the selectively grown ZnO nanorods are pure and contamination free. XRD and electron diffraction patterns revealed that the obtained ZnO nanorods have a wurtzite single-crystal structure. 相似文献
139.
E. N. Brazhnikova Yu. Yu. Gavronskaya V. N. Pak 《Russian Journal of General Chemistry》2009,79(7):1421-1424
The two-stage synthesis of nanosize silver in the pore space of a perfluorosulfonic membrane by ion-exchange fixation of Ag+ cations with the subsequent photoreduction in formaldehyde vapor was fulfilled. The study of the obtained composites shows
that they contain silver “near-wall” form and nanoparticles weakly connected with the membrane surface. 相似文献
140.
In the present paper, necessary and sufficient conditions are given for the equality of the power rezidue symbols
( \fracaa )n {\left( {\frac{\alpha }{a}} \right)_n} and
( \fracaa )n {\left( {\frac{\alpha }{a}} \right)_n} in the cyclotomic field ℚ(ζ
n
), 2 ∤ n, for a ∈ ℤ, (a, n) = 1. This result is a generalization of the classical Eisenstein reciprocity law and its continuation in a Hasse’s paper.
Bibliography: 3 titles. 相似文献