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Novel inorganic hydrogen-bonded crystals with nonlinear optical properties  

International Nuclear Information System (INIS)

Four inorganic hydrogen-bonded crystals with second-order nonlinear properties have been discovered: K_4LiH_3(SO_4)_4, Na_2SeO_4#centre dot#H_2SeO_3#centre dot#H_2O, Cs_1_,_5Li_1_,_5H(SO_4)_2 and NH_4HSeO_4. (author)

2000-01-01

2

Studies of the reduction mechanism of selenium dioxide and its impact on the microstructure of manganese electrodeposit  

British Library Electronic Table of Contents (United Kingdom)

The influence of selenium dioxide (SeO2) on the microstructure and electrodeposition of manganese coatings obtained from a sulfate based neutral solution was investigated by material characterization methods and electrochemical techniques. The crystal structure and surface morphology of these coatings were studied by scanning electron microscopy (SEM) and powder X-ray diffraction spectroscopy (XRD), respectively. The SEM and XRD data showed that SeO2 could effectively accelerate phase transformation, and facilitate leveled and fine grain growth. The electrochemical results indicated that SeO2 could inhibit hydrogen evolution reaction and promote manganese deposition. The action of selenium dioxide in manganese deposition was found to be a reduction and adsorption mechanism. The process cou...

2011-01-01

3

Sorption of arsenite and arsenate on ferrihydrite: Effect of organic and inorganic ligands  

British Library Electronic Table of Contents (United Kingdom)

We studied the sorption of As(III) and As(V) onto ferrihydrite as affected by pH, nature and concentration of organic [oxalic (OX), malic (MAL), tartaric (TAR), and citric (CIT) acid] and inorganic [phosphate (PO4), sulphate (SO4), selenate (SeO4) and selenite (SeO3)] ligands, and the sequence of anion addition. The sorption capacity of As(III) was greater than that of As(V) in the range of pH 4.0-11.0. The capability of organic and inorganic ligands in preventing As sorption follows the sequence: SeO4~SO43 PO4. The efficiency of most of the competing ligands in preventing As(III) and As(V) sorption increased by decreasing pH, but PO4 whose efficiency increased by increasing pH. In acidic systems all the competing ligands inhibited the sorption of As(III) more than As(V), but in alkaline e...

2011-01-01