Effect of Compressive and Stretching Strains on the Dislocation Luminescence Spectrum in Silicon

Semiconductors - The photoluminescence of silicon strained by four-point bending at the temperature 600°C is studied. The so-called dislocation luminescence lines D1, D2, D3, and D4 are...     

Nanosecond detector of infrared radiation based on thin pyroelectric films

The features of detection of short radiation pulses by thermal detectors based on thin pyroelectric films with the radiation energy deposited in a thin absorbing electrode are considered. It is demonstrated that the minimum response time of the sample to radiation pulses is determined by the time of thermal relaxation of the absorbing electrode. Specifically, picosecond pulses may be detected with a 0.5-μm-thick pyroelectric film and a 0.01-μm-thick absorbing electrode.     

Dimensionality reduction in optimal control and estimation problems for systems of solid bodies with low dissipation

We use the method of integral manifolds to reduce optimal control and filtering problems in application to mechanical systems with low friction.     

Formation of active sites in titanium-containing zeolites with MFI structure in propylene epoxidation with hydrogen peroxide

Propylene epoxidation with hydrogen peroxide on titanosilicates with different Si/Ti ratios and various states of titanium in the catalysts, prepared by hydrothermal crystallization according to two different procedures, has been investigated. It has been demonstrated that a change in the pH of the crystallizing gel leads to a change in the sequence of titanium insertion in the zeolite structure at a hydrothermal synthesis temperature of 170°C. It was shown that titanium incorporated in the zeolite framework in the tetrahedral positions is an active site in the epoxidation reaction, whereas titanium in the form of titanium dioxide leads to unproductive degradation of hydrogen peroxide.