应用油团聚技术制备超低灰分煤的研究

介绍油团聚（SGHFF）技术高效脱除煤中灰分的研究过程。含灰分达30.79%、含硫分达2.16%的原料煤，经过四步浮选后，得到含灰分4.06%、含硫分0.72%的超低灰分、硫分煤，灰分去除率达87%、硫分的去除率达67%。探讨了影响油团聚技术选煤过程的主要因素。

INDIUM OHMIC CONTACTS TO N-ZNSE

The reaction between an indium over layer and high purity MBE grown n-ZnSe chlorine doped (2x 10(18) cm-3) epilayers has been investigated using X-ray diffraction, Rutherford backscattering spectroscopy, X-ray photoelectron and Auger electron spectroscopy, and by electrical function tests (I-V and C-V). Good ohmic contacts were formed after annealing at 250 or 300-degrees-C for a few minutes in forming gas. Annealing at lower or higher temperatures resulted in higher resistance or rectifying contacts. The data show that no compounds were formed at the interface; instead In appeared to diffuse into the ZnSe. High surface doping densities appear to allow an ohmic contact, but the electrical data suggest that compensation effects are also very significant in the formation of the contact. These effects must be considered for successful formation of the ohmic contact.

Magnetospectroscopy of bound phonons in high purity GaAs

Far infrared magnetophotoconductivity performed on high purity GaAs reveals the existence of fine structures in the resonant magnetopolaron regions. The fine structures are attributed to the presence of bound phonons due to multiphonon processes. We demonstrate that the magnetopolaron energy spectrum consists of bound phonon branches and magnetopolaron branches. Our results also indicate that different phonons are bound to a single impurity, and that the bound phonon in Si-doped GaAs is a quasilocalized mode.