Self polarization in GaAs–(Ga, Al)As quantum well wires: electric field and geometrical effects

The response of an electron to an external electric field in different shapes of infinite quantum well wires has been investigated. The self-polarization effect which can be defined as the influence of the barrier potential on the impurity electron is studied for the quantum well wire of square, rectangular and cylindrical cross-sections. An external electric field vanishes due to the self-polarization effect has been calculated. It is shown that the self-polarization effect outside of the center depends on both the geometrical form of the wire and the impurity position in the same structure.     

Azole chemistry. V. Synthesis and spectral properties of thiazolo[3,2-d] tetrazolium salts

Thiazolo[3,2-d] tetrazolium salts were obtained by treatment of 5-mercapto-1-phenyl-1,2,3,4-tetrazole with α-bromo ketones followed by cyclodehydration. The spectral properties of the salts and the β-keto sulfide precursors were investigated.     

Reaction of diphenylcyclopropenethione with Mn(CO)5−: Ring cleavage,alkylation, and reduction

Alkylation, reduction, and ring opening of diphenylcyclopropenethione to a π-allyl complex occurs on treatment with Mn(CO)₅^? and methyl iodide in aqueous methanol.     

Iodide ion promotion of benzyl chloride-borate ester carbonylation reactions

Esters are isolated in fine yields from the rhodium(I) catalyzed reaction of benzyl chlorides with borate esters and carbon monoxide, in the presence of potassium iodide.     

A simple synthesis of thioketonemolybdenum carbonyl complexes. An example of geometric isomerism

Thioketones react with molybdenum hexacarbonyl in tetrahydrofuran (60–65°C, 2–3 h) to give molybdenum pentacarbonyl complexes in 52–80% yield. Geometric isomers were isolated in the case of thiocamphor.     

Educational Models,Manpower, Planning and Control

The paper describes the setting up of models of the educational system and their use in decision-making. The methodological problems of planning and controlling a large socio-economic system, such as education, are discussed.