Abstract: Processes for the conversion of hydrocarbons, and most preferably methane, to higher hydrocarbons and olefins are disclosed, including contacting the hydrocarbons with a mixed metal oxide catalyst having the pyrochlore structure. Preferably, these catalysts have the general formula A.sub.n B.sub.2 O.sub.7-x, where A can be various mono-, di-, and trivalent metal cations, B can be various tri-, tetra-, penta-, and hexavalent metal cations, 0.ltoreq.n.ltoreq.2.0, and 0.ltoreq.x.ltoreq.1.0. Novel, high surface area, mixed metal oxide catalysts having the pyrochlore structure are also disclosed, including those having the formula A.sub.2 B.sub.2 O.sub.7, where A is divalent and B is niobium and/or tantalum, and those having the formula A.sub.2 (Sn.sub.2-y A.sub.y)O.sub.7-z, where A is bismuth and/or lead, 0.0.ltoreq.y.ltoreq.1.0, and 0.0.ltoreq.z.ltoreq.1.0.

Abstract: Processes for the conversion of hydrocarbons, and most preferably methane, to higher hydrocarbons and olefins are disclosed, including contacting the hydrocarbons with a mixed metal oxide catalyst having the pyrochlore structure. Preferably, these catalysts have the general formula A.sub.n B.sub.2 O.sub.7 -x, where A can be various mono-, di-, and trivalent metal cations, B can be various tri-, tetra-, penta-, and hexavalent metal cations, 0.ltoreq.n.ltoreq.2.0, and 0.ltoreq.x.ltoreq.1.0. Novel, high surface area, mixed metal oxide cataysts having the pyrochlore structure are also disclosed, including those having the formula A.sub.2 B.sub.2 O.sub.7, where A is divalent and B is niobium and/or tantalum, and those having the formula A.sub.2 (Sn.sub.2-y A.sub.y)O.sub.7-z, where A is bismuth and/or lead, 0.0.ltoreq.y.ltoreq.1.0, and 0.0.ltoreq.z.ltoreq.1.0.

Abstract: Methods for separating uranium isotopes are disclosed including irradiating certain uranyl ion-containing compounds with radiation of a wavelength, .lambda., at which the compounds have a predetermined absorption cross section .sigma..sub..lambda. at a power> kw/cm.sup.2 times.sigma..sub..lambda. /4.times.10.sup.-18 cm.sup.2.

Abstract: Novel compositions of matter are disclosed having the formula UO.sub.2 AA'L.sub.n, wherein n is 0 or 1, and in which A and A' are anions whose conjugate acids have boiling points less than about 200.degree. C. and pK.sub.a values of 4.8 or less, L is a neutral ligand having a boiling point less than about 190.degree. C. and having an equilibrium constant for the exchange reaction with tetrahydrofuran of between about 10.sup.-3 and 10.sup.3, and the combination of A, A' and L satisfy five or six coordination sites of the central uranium atom.

Abstract: In one application, the apparatus is used with unstable laser resonators which include a gain region defined by a concave mirror and a convex mirror. The apparatus includes a spectral line selection medium, such as a multiple band pass filter or a multiple diffraction grating, which is located so that the laser beam directed out of the laser gain region impinges thereon. A retroreflector is positioned so that the spectral lines selected by the line selection medium are reflected back into the laser gain region along the propagation path of the incident beam, resulting in a lockup of the laser at the selected spectral lines.