The Method of Virtual Experts in Mathematical Diagnostics

Mathematical Diagnostics (MD) deals with identification problems arising in different practical areas. Some of these problems can be described by mathematical models where it is required to identify points belonging to two or more sets of points. Most of the existing tools provide some identification rule (a classifier) by means of which a given point is assigned (attributed) to one of the given sets. Each classifier can be viewed as a virtual expert. If there exist several classifiers (experts), the problem of evaluation of experts’ conclusions arises. In the paper for the case of supervised classification the method of virtual experts (the VE-method) is described. Based on this method, a generalized VE method is proposed where each of the classifiers can be chosen from a given family of classifiers. As a result, a new optimization problem with a discontinuous functional is stated. Examples illustrating the proposed approach are provided. The work of the second author was supported by the Russian Foundation for Fundamental Studies (RFFI) under Grant No 03-01-00668.     

Formation of n-α-diazoacetylureas by the reaction of derivatives of 5-hydroxy-1,2,3-triazole-4-carboxamide with phenylisocyanate and phenyl isothiocyanate

The reaction of derivatives of 5-hydroxy-1,2,3-triazole-4-carboxamide with phenyl isocyanate and phenyl isothiocyanate proceeds at the 4-carboxamide fragment of the first, leading to the formation of derivatives of N-phenyl-N-(2-diazo-2-carbamoylacetyl)urea and -thiourea correspondingly.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1347–1350, October, 1992.     

V4S9Br4: a novel high-spin vanadium cluster thiobromide with square-planar metal core

The novel vanadium thiobromide, V4S9Br4, with a square-planar metal cluster core was synthesized and characterized by single-crystal X-ray diffraction, measurements of magnetic properties and the heat capacity, and DFT calculations of the electronic structure. At the room temperature, the compound displays paramagnetic properties with an independent spin on each V atom and with a weak exchange constant (J approximately 10 cm(-1)). The paramagnetic state is transformed into a low-spin state (AF-type ordering) at low temperatures. This change is accompanied by a heat-capacity anomaly. The observed magnetic and heat-capacity anomalies can be explained by the thermal excitation of electrons on the closely spaced molecular energy levels in the presence of the Jahn-Teller effect.     

Mechanism of formation of radical pairs during the photolysis of 2,6-di-tert-butylquinone diazide in single crystals of 2,6-di-tert-butyl-4-methylphenol

Institute of Chemical Physics, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 4, pp. 141–143, July–August, 1992.     

SO42-/Zr-ZSM-5 超强酸催化剂的制备和表征

以硅溶胶和氧氯化锆为硅源和锆源，采用水热合成的方法制得具有ZSM-5结构的Zr-Si分子筛；用0.5mol/L的硫酸处理该分子筛，并在550℃焙烧，制得具有ZSM-5结构的SO4^2-/ZrO2-SiO2分子筛型的固体超强酸。采用XRD、SEM、TG、IR、NH3-PHD和指示剂法对其结构和酸性进行表征。结果表明，该SO4^2-/ZrO2-SiO2具有ZSM-5结构和超强酸性，其酸强度大于-13.75，且具有良好的热稳定性。     

Exchange and magnetic dipole-dipole interactions in bi- and triradical complexes of Al(III), Ga(III), In(III), and Sn(IV) witho-semiquinones. PM3 calculation

Semiempirical (PM3 with CI) calculations of exchange interactions for the triradical complexes of Al(III), Ga(III), and In(III) and the biradical complex of Sn (IV) with o-semiquinones are carried out. The results are in agreement with both qualitative theoretical assumptions and experimental data. The calculations indicate that the superexchange via the unoccupied porbitals of the central metal ion predominantly determines the multiplicity of the ground states of the complexes. Zero-field splitting constants D are calculated; they also agree well with experimental data. Deceased. Translated fromZhumal Struktumoi Khimii, Vol. 38, No. 6, pp. 1053–1060, November–December, 1997.