J o a c h i m F u c h s u n d E r n s t P e t e r F l i n d t Institut für Anorganische Chemie der Freien Universität Berlin Z . Naturforsch. 34b, 412 -422 (1979); eingegangen am 28. November 1978 Properties, X r a y , Heptatungstate , Paratungstate A , Metatungstate Polytungstates are obtained b y the reaction of hydrated tungsten (VI) oxide with bases or salts after occasional addition of org...

In Methanobacterium wolfei two formylmethanofuran dehydrogenases are present, one of which is a molybdenum- and the other a tungsten enzyme. We report here that also the 'molybdenum' enzyme contained tungsten when the archaeon was grown on molybdenum-deprived medium supplemented with tungstate (1 microM). Unexpectedly the tungsten-substituted molybdenum enzyme was catalytically active and displ...

1. The assimilatory nitrite reductase of the N(2)-fixing bacterium Azotobacter chroococcum was prepared in a soluble form from cells grown aerobically with nitrate as the nitrogen source, and some of its properties have been studied. 2. The enzyme is a FAD-dependent metalloprotein (mol.wt. about 67000), which stoicheiometrically catalyses the direct reduction of nitrite to NH(3) with NADH as th...

Abstract For the first time, single crystals of undoped lithium tungstate and doped by 1.25% molybdenum were grown low-temperature-gradient Czochralski technique. The standard formation enthalpies, lattices stabilization energies, heat capacity determined in temperature range 320-997 K. lattice enthalpy dependence on Mo content was constructed.

We report a parametric anti-Stokes Raman laser using potassium gadolinium tungstate, generating output chiefly at the first anti-Stokes at 508 nm. The compact 4.5 cm long device is pumped by a Q-switched 532 nm laser and uses an off-axis Stokes resonator to provide non-collinear phase matching between the pump and the generated Stokes and anti-Stokes fields. Anti-Stokes output energies up 0.27 ...

Lead tungstate (PbWO4) crystallizes in the scheelite (CaWO4) structure, is transparent (Eg ≈ 4.2 eV), and has a broad intrinsic luminescence band at 420 nm. The high atomic numbers, high density, short electron and γ-ray stopping range, radiation hardness, and short lifetime of its intrinsic luminescence at room temperature (~10ns), have resulted in the selection of PbWO4 as the scintillator fo...