Amorphous semiconducting AsSeI

It is shown on the basis of differential thermal analysis (DTA) of AsSeI samples that a reliable technique ensuring reproducible preparation of vitreous AsSeI has been found. The values of the softening and melting points are 50 °C and 220 °C, respectively.Transmittance study has been done on glasses of general compositionxAs₂Se₃+(1–x). AsSeI (forx=1.0; 0.8; 0.4; 0.0). Samples in the form of slabs of different thickness (d=0.2; 0.5; 1.0; 2.0 mm) were used to determine the wavelength dependence of the absorption coefficientK. On the basis of the results of the quoted measurements performed on thin As₂Se₃ layers in the high absorption region, the optical gap width of vitreous semiconducting AsSeI has been extrapolated, using certain simplified conceptions mentioned in the paper. The value ofE _g at 293 °K and its temperature dependence coefficient=(E _g/T)_p for AsSeI were found to be 1.91 eV and –6.7×10^–4eV/grad, respectively.     

Indirect radiotracer study of the adsorption of organic compounds at platinized platinum electrodes

The possibility of the use of an indirect radiotracer method for the study of the adsorption of organic species has been discussed. It has been shown that by study of the adsorption of Cl-36 labelled chloride ions in the presence of organic species such as maleic, benzoic and m-nitrobenzoic acids there is a possibility of obtaining information concerning the adsorption of the latter compounds. Change in the adsorption behaviour of organic species connected with their electroreduction were detected and followed by indirect tracer measurements. In the light of the experimental results, some mechanistic aspects of the reduction of aromatic nitro compounds are discussed.     

New books

Ohne Zusammenfassung

---

New books

     

Toward cocaine esterase therapeutics

Cocaine is among the most reinforcing of all drugs of abuse, yet no effective pharmacotherapy is available. Herein, we report the development and characterization of phage-displayed cocaine esterases with pharmacologically relevant kinetic parameters (kcat/Km approximately 104 M-1 s-1).