CO2-laser annealing of Al/a-Si:H contact

The paper concerns the possibility of using CW (continuous wave) CO₂-laser annealing (=10.6 m,P 100 W/cm²) for formation of a barrier in the Al/a-Si:H/SS (SS-stainless steel) structures with good rectifyingI–V characteristics. The infrared absorption spectra, photoelectric properties, temperature effect on the conductivity and saturation current were analyzed and various contact models are discussed.We thank P. imanec for useful and stimulating discussion, J. Stuchlík for kindly manufacturing the a-Si:H films for us and D. N. Goncharov for the aid with the measurement of the conductivity temperature dependences.     

Pyrimidines

The reaction of 1-phenyl-3-methyl-4-benzal-5-pyrazolone with urea does not lead to closing of a pyrazolo[3,4-d]pyrimidine ring because of the reduced tendency of the carbonyl group of the pyrazolone to participate in cyclization reactions. The expected 1,4-diphenyl-3-methyl-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidine was obtained by condensation of 1-phenyl-3-methyl-5-aminopyrazole with benzalbisurea and was dehydrogenated to the dihydro derivative.     

Wear resistance of polyethylene

The effect of the molecular weight and branching of polyethylene on its wear resistance in direct contact with abrasive particles has been investigated. The abrasive wear resistance of the polyethylene increases with its molecular weight. Copolymers have better wear resistance than homopolymers."Plastolimer" Research and Production Association, Leningrad. Translated from Mekhanika Polimerov, No. 3, pp. 542–544, May–June, 1971.     

Tunneling through the space charge region in a metal-amorphous silicon contact

By solving for the potential barrier profile in metal-amorphous silicon contacts using an exponential distribution of the density of states in the energy spectrum mobility gap, we compute the voltage-current characteristics of such contacts taking into account tunneling through the space charge region. We demonstrate that as the density of states in the middle of the mobility gap increases, such tunneling leads to significant changes in the rectifying properties of a metal-amorphous silicon contact.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 3–7, November, 1986.     

Optimization of zonal thermal treatment of cylindrical component parts by moving concentrated heat sources

We propose a numerical-analytic method of determining the optimal heating regimes and stress-strain state of steplike cylindrical shells to guarantee the maximally admissible length of the annealing zones in the cirumferential direction and the number of these zones in the absence of residual strains and stresses.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 33, 1991, pp. 65–69.     

Lasing properties of 3CN coumarins

In this report the effects of 3CN substitutions on the spectral luminescence and lasing properties of oxy- and diethylaminocoumarins are studied. In both classes of coumarins the CN group decreases the tuning region of the maximum lasing wavelengths: in aminocoumarine as a result of decreased intermolecular interaction with the solvents, and in the oxy- as a result of a shift in the equilibrium of protolytic reactions towards anion forms. As a result, the lasing efficiency of anion forms of 3CN oxycoumarins increases. The lasing properties of aminocoumarins decrease with the given substitutions, while the probability increases for the formation of nonplanar molecular conformations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 103–106, June, 1988.