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The room-temperature photoluminescence (PL) spectrum of the modulation-doped strained In0.60Ga0.40As/In0.52Al0.48As multiple quantum wells (MQW) is reported. In addition to two strong PL peaks related to the recombination between electrons in the first (n = 1), second ( n = 2) subbands and heavy holes in the first ( n = 1) subband, a weak PL shoulder related to the recombination between n = 1 electrons and n = 1 light holes is obsevered at low temperatures. We demonstrate that the main mechanism of the decrease in radiative QW recombination efficiency is due to the carrier trapping on the misfit dislocations, based on the temperature and excitation power dependence of the PL peak intensity and energy and the steady-state PL model.

In principle, four rypes of aluminum ions on the faujasite framework may be distinguished according to the next neighbour number (0,1,2,3) of aluminum appearing around their environment. The hydrogen ions associated with type-O aluminum ions are to be identified as "strong" acid, and those associated with types 1,2 and 3, as "weak" acid. In a dealuminization process, the "weak acid" aluminum ions (types 1,2 and 3) are removed preferably over the "strong acid" type-O. Based on first-order kinetics, the concentrations of all the four types aluminum ions upon dealuminization can be described in terms of the Monte-Carlo simulation of the dealuminization process of the faujasite. We conclude that the concentration of the strong acid center in dealuminization faujasites come up to its maximum around Si/Al 6.68. We also conclude that the more difference between dissolving rate constants for "strong" and "weak" aluminum ions the denser strong acid in dealuminization faujasite could be expected.

31P nuclei are used as probes in the NMR studies of xLi2O·P2O5·yCdO glass samples with different molar ratio (x, y). The static NMR spectra are obtained through employing the Bruker MSL-300 spectrometer with a operating frequency of 121.487 MHz. Three basic types of phosphorous structure units join together randomly to form networks in the glasses, each of which has its own NMR characteristic. The relative portions of those basic structure units depend on the molar contents of Li2O and CdO, i,e x and y. For the description of the unit portions, we have postulated a simple model, the rationality of which has been justified by the coincidence between the theoretical prediction based on the model and the conclusions obtained from the simulation of the observed NMR powder patterns.

The photoluminescence spectra of conducting polymer P3MT with different doping densities at different excitation intensities and temperatures are reported. It is demonstrated experimentally that there are three kinds of radiative transitions, i.e., direct interband transition, recombination of exciton and radiative transition between polaron level and edge of band for the conducting polymer P3MT with nondegenerate ground state.