Erratum to: Optical Gain of 1550-nm Range Multiple-Quantum-Well Heterostructures and Limiting Modulation Frequencies of Vertical-Cavity Surface-Emitting Lasers Based on Them

Optics and Spectroscopy - The name of the seventh author should read L. Ya. Karachinsky.     

On the stability of shock waves in a continuous medium with a space charge

The stability of shock waves is discussed for a hydrodynamic model of motion of a continuous medium with a space electrical charge. The correctness of a mixed problem obtained by linearization of the hydrodynamic model and the equations of a strong discontinuity for electrohydrodynamic shock waves is proved. As is known, this indicates stability of this type of strong discontinuity in the model of a continuous medium considered. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 2, pp. 29–39, March–April, 1998.     

Vertical-cavity surface-emitting lasers based on submonolayer InGaAs quantum dots

Molecular beam epitaxy-grown 0.98-/spl mu/m vertical-cavity surface-emitting lasers (VCSELs) with a three-stack submonolayer (SML) InGaAs quantum-dot (QD) active region and fully doped Al/sub x/Ga/sub 1-x/As-GaAs DBRs was studied. Large-aperture VCSELs demonstrated internal optical losses less than 0.1% per one pass. Single-mode operation throughout the whole current range was observed for SML QD VCSELs with the tapered oxide apertures diameter less than 2 /spl mu/m. Devices with 3-/spl mu/m tapered-aperture showed high single-mode output power of 4 mW and external quantum efficiency of 68% at room temperature.     

Sorption Purification of Aqueous Ammonium Molybdate To Remove Tungsten Impurities with a Cation Exchanger Containing Pyrocatechol Functional Groups

The sorption of molybdenum(VI) and tungsten(VI) from weakly alkaline and neutral solutions with PK-S cation exchanger containing pyrocatechol functional groups was studied. The possibility of selective recovery of tungsten(VI) impurities from aqueous ammonium molybdate with PK-S resin was examined.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 425–427.Original Russian Text Copyright © 2005 by Blokhin, Kaloshina, Lyubman, Murashkin.     

Heterylimidazoles.

Condensation of 5-formy1-N,N'-dimethylbenzimidazolone with aromatic -diketones gave 2-(N,N'-dimethylbenzimidazolon-5-yl)-4,5-diarylimidazoles, which are easily oxidized in alkaline media to imidazolyl free radicals. Some of the investigated heterylimidazoles also form radicals when chloroform solutions of them are irradiated. It is shown that the synthesized compounds are inhibitors of the thermal oxidative destruction of polyethylene oxide.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 519–521, April, 1978.     

Heterylimidazoles

2-Quinolyl- or 2-(9-acridinyl)-4,5-diarylimidazoles were obtained by the condensation of benzil or p,p-dimethylbenzil with heterocyclic aldehydes in acetic acid in the presence of ammonium acetateTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 681–682, May, 1972.     

Physicochemical properties, structure, and conformations of 1-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4mim]NTf2 ionic liquid

Thermodynamic properties of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim]NTf2) ionic liquid have been studied by adiabatic calorimetry in the temperature range of 5 to 370 K. This compound has been found to form crystal, liquid, and glass. The temperature and enthalpy of fusion for [C(4)mim]NTf(2) have been determined to be T(fus) = 270.22 +/- 0.02 K and Delta(fus)H = 23.78 +/- 0.04 kJ.mol(-1), respectively. The heat capacity of crystalline [C(4)mim]NTf(2) in the T range of 205 to 255 K may vary by a few percent, subject to the procedure of the crystal preparation. The glass transition temperature for [C(4)mim]NTf(2) has been found to be T(g) = 181.5 +/- 0.1 K. On the basis of the results of DFT quantum chemical calculations, the experimental vibrational spectra, and the available literature data, thermodynamic properties of [C(4)mim]NTf(2) in the ideal-gas state have been calculated by the statistical thermodynamic methods. The entropy values for the gaseous compound obtained from the experimental data and the calculations are in satisfactory agreement.