Opisano główne mechanizmy odbicia mikrofal od powierzchni morza: tradycyjny rezonansowy (braggowski) mechanizm, leżący w gruncie ogólnie uznanego dwuskalowego modelu powierzchni morskiej i niedawno opracowany nie-rezonansowy mechanizm, związany z istnieniem na powierzchni morza stromych spadających fal mezoskalowej długości. W połączeniu z dwuskałowym modelem nierezonansowy mechanizm doprowadza do trójskalowego modelu powierzchni morskiej, który zdoła wyjaśnić znacznie większy zakres zjawisk, niż dwuskahwy model.

The article presents multi-component composite model of the sea surface which generalizes the standard twoscale model (small-scale gravity-capillary waves lying on the large-scale gravity waves). The suggested model considers the non-resonant backscatter from large-scale breaking gravity waves and resonant backscatter from the steep wavelets of meso-scale spectrum (meso-waves). The multi-component composite model differs from the standard two-scale composite model in that it involves the non-resonant components against the background of “macro-breaking” large-scale waves, or in the form of “micro-breaking” steep mesowaves. The main goal of this paper is to stimulate further analysis of the angular, frequency and polarization characteristics of the resonant and non-resonant backscatter mechanisms in order to distinguish between them

A self-oscillating ultrasonic system is suggested for monitoring deformations in ship hulls. The system employs high frequency (about 1 MHz) ultrasounds exciting the hull material. Stress changes manifest themselves in small but detectable variations of frequency in the self-oscillating system. The suggested system can be applied for continuous stress changes monitoring in high seas as well as in nearly fully laden ship conditions.

The authors analyze the methods of effective teaching of physics in the context of an increasingly weak preparation of students from the high school. They draw attention to the opportunities that in this field can offer new multimedia technologies, especially computers, applied to various forms of physical classes. The analysis is based on many years of experience in working with students of different specialties and in different countries