Phenomenological model of creep under variable loads

Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, No. 4, pp. 123–127, July–August, 1993.     

Remote helicopter-borne detector for searching of methane leaks

Measurements of the content of various molecular impurities in the ambient air using helicopter- and aircraft-borne systems represent an extremely urgent challenge. In this respect, of special interest are the devices that that provide leakage monitoring in gas lines in order to prevent emergencies. In the paper results of the tunable diode laser-based instrument development and testing are presented.     

Reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2-2λ3-phospholidine withC,N-diphenylnitriliminewithC,N-diphenylnitrilimine

The reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2λ³-phospholidine withC,N-diphenylnitrilimine is a multistage process, in the course of which the 1,2,4-diazaphosphorine ring is formed and both rings of the initial organophosphorus compound are cleaved. 5-(2-Chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,3-diphenyl-1,4-dihydro-1, 2,4λ⁵-diazaphosphorine was obtained as the final product. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 2000.     

Reaction of (Pentafluorophenyl)diphenylphosphine with Azadicarboxylic Acid Dimorpholide

Russian Journal of General Chemistry -     

Duality, triality and complementary extremum principles in non-convex parametric variational problems with applications

This paper presents a reasonably complete duality theory anda nonlinear dual transformation method for solving the fullynonlinear, non-convex parametric variational problem inf{W(u- µ) - F(u)}, and associated nonlinear boundary valueproblems, where is a nonlinear operator, W is either convexor concave functional of p = u, and µ is a given parameter.Detailed mathematical proofs are provided for the complementaryextremum principles proposed recently in finite deformationtheory. A method for obtaining truly dual variational principles(without a dual gap and involving the dual variable p* of uonly) in n-dimensional problems is proposed. It is proved thatfor convex W(p), the critical point of the associated LagrangianL_µ(u, p*) is a saddle point if and only if the so-calledcomplementary gap function is positive. In this case, the systemhas only one dual problem. However, if this gap function isnegative, the critical point of the Lagrangian is a so-calledsuper-critical point, which is equivalent to the Auchmuty'sanomalous critical point in geometrically linear systems. Wediscover that, in this case, the system may have more than oneprimal-dual set of problems. The critical point of the Lagrangianeither minimizes or maximizes both primal and dual problems.An interesting triality theorem in non-convex systems is proved,which contains a minimax complementary principle and a pairof minimum and maximum complementary principles. Applicationsin finite deformation theory are illustrated. An open problemleft by Hellinger and Reissner is solved completely and a purecomplementary energy principle is constructed. It is provedthat the dual Euler-Lagrange equation is an algebraic equation,and hence, a general analytic solution for non-convex variational-boundaryvalue problems is obtained. The connection between nonlineardifferential equations and algebraic geometry is revealed.     

10-(3-Hydroxypropyl)-1,4,6,8-tetraphenyl-1,4,7,8-tetraaza-5-phosphoniaspiro[4.5]deca-6,9-diene chloride: synthesis and molecular structure

The reaction of 2-(3,4-dihydro-2H-pyran-5-yl)-1,3-diphenyl-1,3-diaza-2³-phospholidine with C,N-diphenylnitrilimine yields 10-(3-hydroxypropyl)-1,4,6,8-tetraphenyl-1,4,7,8-tetraaza-5-phosphoniaspiro[4.5]deca-6,9-diene chloride. Its structure was determined by X-ray diffraction analysis.     

Model for the calculation of the trajectories of electron movements in an aqueous environment placed in a magnetic field

In this work the application of a rather simple half-analytic model for plotting and studying electron trajectories in an aqueous environment in a transverse magnetic field was considered. The energies of electrons used in medical electron accelerators, viz., those up to 30 Me, were considered and the induction value of the magnetic field was changed within limits up to 3 T. Our data are compared with those in the works of other authors, who used the Monte Carlo simulation method, as well as with experimental data.     

Synthesis of 3-Azido-5-amino-1,2,4-triazole

3-Azido-5-amino-1,2,4-triazole was obtained from 3,5-diamino-1,2,4-triazole in two ways: by partial diazotization-substitution directly in the substrate or at its primarily nitrosation, and also with the use of direct or indirect protection of an amino group with subsequent conversion into azido compound followed by deprotection.     

Reactions of 2-(4,5-dihydro-3-furyl)-1,3-diphenyl-1,3-diaza-2λ<Superscript>3</Superscript>-phospholidine and 4,5-dihydro-3-furylphosphonous diamides with nitrile imines

Reactions of 2-(4,5-dihydro-3-furyl)-1,3-diphenyl-1,3-diaza-2λ³-phospholidine (1) with nitrile imines are multistep processes involving cleavage of one P-N bond of the diazaphospholidine ring to form substituted 5-(2-chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,4-dihydro-1,2,4λ⁵-diazaphosphorines 4 as final products. Analogs of phospholidine 1, namely, 4,5-dihydro-3-furylphosphonous dipiperidide and dimorpholide, react with C,N-diphenylnitrile imine with retention of both P-N bonds to give 5-(2-hydroxyethyl)-1,2,4-diazaphosphorinium chlorides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1590–1593, July, 2005.