Modification of silica gels with small admixtures of titanium ions

Microporous silica gels containing small amounts of titanium ions are synthesized. Addition of Ti ions to the silica gels during the sol-forming step is demonstrated to increase the specific surface area and decrease the volume of sorptive pores. Spectral results indicate that Ti ions uniformly distribute in the silica gel matrix and isomorphously replace Si.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2217–2222, October, 1991.     

Synthesis and Structure of Bis(tetraphenylantimony) Tetrafluorophthalate

Oxidation of pentaphenylantimony with atmospheric oxygen in toluene on heating gives -oxo-bis(tetraphenylantimony) (yield 63%). Its reaction with tetrafluorophthalic anhydride gives bis(tetraphenylantimony) tetrafluorophthalate (yield 94%). According to single-crystal X-ray diffraction data, the antimony atoms in the molecule of bis(tetraphenylantimony) tetrafluorophthalate have a distorted trigonal bipyramidal coordination with the following geometries: Sb-O bond lengths 2.357(3) and 2.283(3) Å, Sb-C bond lengths 2.108(4)-2.141(4) and 2.100(5)-2.158(4) Å, and CSbO angles 177.42(14)° and 176.18(14)°.     

Chemical Transformations of 9,11-Ethano-13,15-isoxazolinoprostanoids

Chemical transformations of 9,11-ethano-13,15-isoxazolinoprostanoids furnished new prostanoids with a bufunctional fragment of -hydroxyketone and -aminoalcohol in the -chain. The reaction of -hydroxyketones with methanesulfonyl chloride gave rise to prostanoids with an enone component in the -chain. 9,11-Ethano-16-thiaprostanoids were prepared for the first time by nucleophilic addition of thiols to the polarized double bond in the -chain. The 1,3-dipolar addition to terminal alkenes of nitrile oxides generated from nitromethylene derivatives of bicycloheptane provided 9,11-ethano-13,15-isoxazolinoprostanoids with an alkyl, phenyl, or additional heterocyclic fragment in the -chain.     

Stresses in an elastic body under nonlinear antiplane deformation

The stress field in a cylindrical elastic body under antiplane deformation and certain constraints imposed on volume and surface forces is studied in a nonlinear formulation in actualstate variables. A boundaryvalue problem for independent stress components is formulated in Cartesian and complex variables, sufficient ellipticity conditions for this problem are indicated, and constraints on surface loading are imposed. Analytical solutions are given for linear and weak nonlinear elastic potentials. Similarity to a plane subsonic idealgas flow is established. An approximate method for the solution of the problem is developed.     

Calculation of the stress-strain state and stability of laminated shells with allowance for the actual properties of the materials of the layers

Kiev Automobile-Transportation Institute. Translated from Prikladnaya Mekhanika, Vol. 28, No. 2, pp. 38–46, February, 1992.