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21.
    
Diffuse reflectance spectroscopy and X-ray phase analysis studies of Ag/–Al2O3 catalysts have revealed that in thermal decomposition of supported silver nitrate part of Ag+ ions are oxidized to Ag2+ and Ag3+ ions localized in the carrier lattice, which preserve up to temperatures above 900 °C.
Ag/–Al2O3 . , Ag+ Ag2+ Ag3+, 900 °C.
  相似文献   
22.
In this work two non-local problems for the parabolic-hyperbolic type equation with non-characteristic line of changing type are considered. Unique solvability of these problems is proven. The uniqueness of the solution is proven by the method of energy integrals and the existence is proven by the method of integral equations.  相似文献   
23.
We study the Cauchy problem for an equation with singular Bessel operator. Unlike traditional methods to solve this problem, we apply Erde´ lyi–Kober fractional operator and find an explicit formula for the desired solution. We prove that the resulting formula is a unique classical solution to the problem.  相似文献   
24.
25.
The collective acceleration of laser plasma ions in a magnetic field generated by a powerful fast-growing current pulse in a low-inductive conical spiral is studied. The velocity of ions for a number of elements which significantly differ in atomic weight are obtained on the basis of collector measurements. The maximum velocity of both light (lithium) and heavy (lead) ions exceed the value of 108 cm/s; for ions of lead, the corresponding energy amounts to a value of ∼1 MeV. A mathematical model of ion acceleration is proposed and simulation results are compared with the experiment.  相似文献   
26.
Crystallography Reports - Sm1 – ySryF3 – y (0 < y ≤ 0.31) crystals have been grown from melt by directional solidification in a...  相似文献   
27.
Crystallography Reports - Nd1 – yEuyF3 – y crystals (y is the molar fraction of EuF2; 0 ≤ y ≤ 0.15) with a tysonite (LaF3) structure have...  相似文献   
28.
The alkaloid composition of young shoots and leaves ofBerberis heteropoda Schrenk has been studied. In addition to known alkaloids, two new ones have been isolated — N-methyldihydroberberine and 8-oxoberberrubine, the structures of which were established by chemical transformations and a study of spectral properties. Of known alkaloids, berbamunine, aromoline, glaucine, thalicmidine, isocorydine, and reticuline have been found in this plant for the first time. Pseudopalmitine and laudanosine have been found for the first time in plants of the genusBerberis.Andizhan State Medical Institute. Institute of the Chemistry of Plant Substances of Uzbek Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 53–59, January–February, 1993.  相似文献   
29.
Spectral properties and chemical stability of Mn(III), Mn(IV), Fe(III), Fe(IV), and Cu(III) complexes of β-octabromotriphenylcorrole [(β-Br)8(ms-Ph)3Cor], synthesized from β-unsubstituted compounds by their reaction with molecular bromine, were studied. Cyclic voltammetry, electron microscopy, and X-ray spectral microanalysis were used to obtain electrochemical characteristics of metal corroles M(β-Br)8(ms-Ph)3Cor and gain insight into the surface texture of active catalysts on the basis of metal corroles. The electron-acceptor β-bromine substitution in the MCor macrocycle shifts the equilibrium in electron-donor solvents to lower oxidation states of the metals and also stabilizes manganese and destabilizes copper complexes in the protondonor medium HOAc-H2SO4. The electrocatalytic activity of the complexes in the reduction of molecular oxygen depends on the nature of the ligand and increases in the order Mn ≤ Cu ? Fe in the case of β-octabrominated macrocycles. The character of distribution of active centers on the surface of the catalysts was established for the first time.  相似文献   
30.
Two species of Berberis have yielded 10 isoquinoline alkaloids. In addition to known bases, two artifacts have been isolated — 8-trichloromethyldihydroberberine (I) and 8-trichloromethyldihydropalmatine. An x-ray structural analysis has been made of (1).Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 889–893, November–December, 1996. Original article submitted April 15, 1996.  相似文献   
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