Methyl triflate reacts with the metastable azoxymetallacyclopentene complex Cp*2Zr(N(O)NCPhCPh), generated in situ from nitrous oxide insertion into the Zr-C bond of Cp*2Zr(η2-PhCCPh) at -78 °C, to afford the salt [Cp*2Zr(N(O)N(Me)CPhCPh)][O3SCF3] (1) in 48% isolated yield. A single-crystal X-ray structure of 1 features a planar azoxymetallacycle with methyl alkylation taking place only at the ...

A series of zirconium-based porous coordination polymers (PCPs) containing FI catalysts in the frameworks have been developed and studied as catalysts for ethylene polymerization. These PCPs exhibit good catalytic activities and long life times, producing polyethylenes with high molecular weights and bimodal molecular weight distribution in the form of particles.

Results are presented from the ongoing international study, namely Chernobyl Pilot Site Project, aimed at characterization and modeling of process controlling Sr releases from the shallow trench at Chernobyl NPP site containing nuclear fuel particles and subsequent radionuclide transport in the underlying eolian and alluvial sand aquifer. Microscopic analyses of fuel particles separated from wa...

The modification of different zirconium propoxide and hafnium propoxide precursors with 2,2,6,6,-tetramethyl-3,5-heptanedione (Hthd) was investigated by characterization of the isolated modified species. The complexes [Zr(OnPr)3(thd)](2), [Zr(OnPr)(OiPr)2(thd)]2, Zr(OiPr)(thd)3, [Hf(OnPr)3(thd)]2, and Hf(OiPr)(thd)3 were isolated and characterized. The structure of the n-propoxide analogue of Z...

A generating set for the wreath product Zr ≀ Sn which leads to a nicely behaved weak order is presented. It is shown that the resulting poset has properties analogous to those of the weak order on the symmetric group: it is a self-dual lattice, ranked by the Foata–Han flag inversion number; any two maximal chains are connected via Tits-type pseudo-Coxeter moves; and its intervals have the desir...

Tungstated zirconia is a robust solid acid catalyst for light alkane (C(4)-C(8)) isomerization. Several structural models for catalytically active sites have been proposed, but the topic remains controversial, partly because of the absence of direct structural imaging information on the various supported WO(x) species. High-angle annular dark-field imaging of WO(3)/ZrO(2) catalysts in an aberra...

For the first time, various hydride phases in a zirconium-hydrogen system have been prepared in a high-energy synchrotron X-ray radiation beamline and their transformation behaviour has been studied in situ. First, the formation and dissolution of hydrides in commercially pure zirconium powder were monitored in real time during hydrogenation and dehydrogenation, then whole pattern crystal struc...

Passivation on polycrystalline Zr (hcp) and Ta (bcc) depends on the crystallographic orientation of the individual grains, determined by electron back scattering diffraction (EBSD). Microelectrochemical experiments yield characteristic data, such as oxide formation potentials, formation factors, capacities, and thicknesses, of local oxide formation on single grains. Strong differences occur on ...

Enikoe Seres,1,* Jozsef Seres,1 Carles Serrat,2 and Shinichi Namba3 3 1Institute of Atomic and Subatomic Physics E141, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria 4 2Universitat Politècnica de Catalunya, Departament de Fı́sica, Colom 11, 08222 Terrassa, Spain 5 3Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527...

We describe a criterion for showing that the equation s2+y2p = α3 has no non-trivial proper integer solutions for specific primes p > 7. This equation is a special case of the generalized Fermat equation xp + yq + zr = 0. The criterion is based on the method of Galois representations and modular forms together with an idea of Kraus for eliminating modular forms for specific p in the final stage...