Piezoelectrically Mediated Reversible Addition-Fragmentation Chain Transfer Polymerization

A well-controlled piezoelectrically mediated reversible addition-fragmentation chain transfer polymerization (piezo-RAFT) was carried out under ultrasound agitation with piezoelectric ZnO nanoparticles as the mechano-chemical trans-ducer. The resulting polymer had predictable molecular weight, high end-group fidelity, low dispersity, and capacity for chain extension. This chemistry was further adopted in curing composite resins to circumvent the light penetration limit of UV curing. This work opened a new avenue of piezoelectrically mediated chemistry and showed its good potential in curing applications.

Fourier analysis of spectral characteristics of a matrix photodetector in the frequency and time domain

The purpose of this paper is to research the frequency and time characteristics of the photo-detector using the direct and inverse Fourier transform. The spectral characteristics of the matrix photodetector were selected as the object of research. For the channels of the trans-ducer it was found that the frequency spectrum consists of two elementary bands in the form of Gaussian curves. It was revealed that the spectra have super-broadband properties. The impulse (time) characteristic of the spectra is described by the equation in an analytical form, which is in good agreement with the calculation. The rise time of the transient response is 1.8–2.9 fs. The process of absorption of light is significantly influenced by dielectric relaxa-tion of the charge. The results obtained provide important information on the properties of the photodetector in the frequency and time domain.