Crystalline hosts with low phonon energies enable novel energy transfer processes when doped with rare earth ions. Two applications of energy transfer for rare earth ions in thulium-sensitized low phonon energy crystals that result in infrared luminescence are discussed. One application is an endothermic, phonon-assisted cross-relaxation process in thulium-doped yttrium chloride that converts l...

2/3 of the reservoir surface area was approximately covered with dense populations of Myriophyllum, Ceratophyllum and Potamogeton species. The headwaters of the reservoir were considered as hard water and had both carbonatic and non-carbonatic hardness. When they were exposed to lentic condition of the reservoir and its intensive photosynthetic activities of macrophyte communities, the bicarbon...

"Aluminium hydroxide dissolves in acids. From its solution in hydrochloric acid, an aluminlum salt, aluminium chloride A1C13, 6H20, is obtained. I t also combines with strong bases, dissolving for instance in a solution of sodium hydroxide and forming an aluminate, NaA102 . . . . According to the best knowledge we have on the subject, the molecule of aluminium hydroxide has the following struct...

The modulation of solubilized type 1 and type 2 benzodiazepine receptors from cow brain by gamma-aminobutyric acid (GABA), divalent cations, and anions has been evaluated. GABA stimulates [3H] flunitrazepam binding of both receptor subtypes, whereas divalent cations and anions selectively stimulate solubilized type 2 receptors. Of numerous anions examined, only chloride, bromide, and iodide enh...

The rate of hydrochloric acid production by isolated, bullfrog gastric mucosae depends critically on the supply of chloride ion to the serosal surface. Secretion of acid is negligible if chloride is completely replaced by glucuronate and gluconate ion. The experimental evidence indicates that the rate of acid secretion may be regarded as a reaction velocity, depending on chloride concentration ...

Unlike the NaCl-secreting salt glands of many birds and reptiles, the nasal salt glands of lizards can secrete potassium as well as sodium, with either chloride or bicarbonate as the accompanying anion. The factors responsible for initiating secretion by the gland and the rates of cation and anion secretion were studied in the desert iguana, Dipsosaurus dorsalis. Lizards were given combinations...

Ascidians, so-called sea squirts, can accumulate high levels of vanadium in the vacuoles of signet ring cells, which are one type of ascidian blood cell and are also called vanadocytes. In addition to containing high concentrations of vanadium in the +3 oxidation state, the proton concentrations in vanadocyte vacuoles are extremely high. In order to elucidate the entire mechanism of the accumul...

The complex formation between cobalt(II) and chloride ions in molten NH4NO3·2.61H2O, NH4NO3·CH3CONH2·1.61H2O and NH4NO3·2.61CH3CONH2 has been investigated. Absorption spectra of cobalt(II) chloride containing variable amounts of ammonium chloride were recorded at 45 to 60 ◦C. In the absence of chloride, the solutions show spectra typical for octahedral co-ordination of cobalt(II). Addition of c...