Magnetic susceptibility of the suicides and germanides Me5Si3 and Me5Ge3 (Me=Sc,Ti, V)

Russian Physics Journal -     

Halogen-substituted pyridines. 3. Cyclization of adducts of α,α-dichloropropionitrile with acrylic derivatives to chloropyridines

Reactions of ,-dichloropropionitrile with acrylic derivatives in the presence of Cu₂Cl₂ gave a series of substituted 2,4-dichloro- and 2-chloro-5-oxoalkanonitriles. Their cyclization to chloropyridines has been studied.For Communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 514–519, April, 1989.     

Acceleration by Double Activation Catalysis and its Negation with Rising Temperature in Hydrolysis of Cellobiose with Phthalic and Hydrochloric Acids

Double activation catalysis was experimentally observed in hydrolysis of cellobiose catalyzed simultaneously with phthalic and hydrochloric acids, confirming earlier theoretical prediction known from literature. Both acids can catalyze the reaction individually, and contribution of the double-activation pathway to the total reaction rate declines as temperature increases. In fact, above a certain temperature, the hydrolysis rate in presence of both acids becomes lower than the sum of the rates for the two acids acting individually. A kinetic model is proposed to explain this transition between double-activated catalysis and inhibition. The trend of declining contribution of cooperative catalytic pathway with rising temperature is theorized to be generally applicable for any reaction with a pathway involving simultaneous action of two catalysts when either of them can individually catalyze the reaction.     

Asymptotic theory of the flow near the rear end of a slender axisymmetric body

Steady high-Reynolds-number flow of a viscous incompressible fluid past a slender axisymmetric body is considered. The structure of the near wake and the boundary layer in the vicinity of the rear end of the body is studied. The relationship between the maximum relative body thickness and the rearend shape giving a local boundary layer — potential flow interaction zone in a small neighborhood of the rear end is found. The boundary value problem for this region is solved numerically.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 5, pp. 68–77, September–October, 1993.     

Properties of similarity solutions for flows in turbulent vortex cores

A class of similarity solutions of the equations for turbulent vortex cores matching an external inviscid similarity flow with a power law of circumferential velocity variationv-r ^−m near the rotation axis and constant Bernoulli function is considered. Solutions are found to exist only in a certain range of the indexm of the exponential. For each suchm there are two solutions. The authors wish to apologise for a mistake which resulted in the figures in this paper corresponding to [1] and those in [1] corresponding to this paper. Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 60–64, May–June, 1998. The work was financially supported by the Russian Foundation for Basic Research (project No. 95-01-00483).     

Asymptotic theory of turbulent separation

The flow of an incompressible fluid in the viscous wall sublayer of a turbulent boundary layer in the neighborhood of a point of separation is considered. On the basis of an asymptotic analysis of the Reynolds equations and without the use of any hypotheses about their closure it is shown that at large Reynolds numbers the velocity profile satisfies the well-known “half-power law,” and as a result of a large self-induced pressure gradient separation is preceded by the appearance of reverse flows in a thin viscous sublayer.