In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the fe...In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the features of the practical realization of ultrasonic imaging systems based on phased arrays and offers an alternative solution of imaging on the basis of the acoustic lenses of refractive and diffraction types. Using lenses eliminates many of the technical and technological problems associated with the development of multi-element phased arrays. It is shown that lens systems allow using traditional methods of transformation of acoustic fields into the visible images by 2D piezo matrix and a more promising way of acoustooptical transformation based on coherent optical interferometry.展开更多
It is shown that the estimation of nonlinear distortions in the various circuits based on the measurement of the ratio of the dispersion and correlation functions does not depend on the level of additive noise acting ...It is shown that the estimation of nonlinear distortions in the various circuits based on the measurement of the ratio of the dispersion and correlation functions does not depend on the level of additive noise acting on the input (or output) of nonlinear circuit. The proposed theoretical method is confirmed by experimental measurements.展开更多
The discussed physical model of the primary visual perception is based on the joint consideration of the structural features of the retina and its functioning, namely, inversion of the retina, the presence of micro-os...The discussed physical model of the primary visual perception is based on the joint consideration of the structural features of the retina and its functioning, namely, inversion of the retina, the presence of micro-oscillations (tremor), high rate of reaction of photoisomerization and its spatial-time coherence. The above model indicates the existence of significant forward light scattering in the layers of the retina. The existence of micro-oscillations and partial time coherence of the first stage of photoisomerization reaction allows proposing a mechanism of image restoration based on the principles of holographic speckle interferometry.展开更多
文摘In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the features of the practical realization of ultrasonic imaging systems based on phased arrays and offers an alternative solution of imaging on the basis of the acoustic lenses of refractive and diffraction types. Using lenses eliminates many of the technical and technological problems associated with the development of multi-element phased arrays. It is shown that lens systems allow using traditional methods of transformation of acoustic fields into the visible images by 2D piezo matrix and a more promising way of acoustooptical transformation based on coherent optical interferometry.
文摘It is shown that the estimation of nonlinear distortions in the various circuits based on the measurement of the ratio of the dispersion and correlation functions does not depend on the level of additive noise acting on the input (or output) of nonlinear circuit. The proposed theoretical method is confirmed by experimental measurements.
文摘The discussed physical model of the primary visual perception is based on the joint consideration of the structural features of the retina and its functioning, namely, inversion of the retina, the presence of micro-oscillations (tremor), high rate of reaction of photoisomerization and its spatial-time coherence. The above model indicates the existence of significant forward light scattering in the layers of the retina. The existence of micro-oscillations and partial time coherence of the first stage of photoisomerization reaction allows proposing a mechanism of image restoration based on the principles of holographic speckle interferometry.
