960 research outputs found

    Energy distribution functions of ions impinging on substrate in microwave plasma

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    Using retarding field energy analyser, we measured ion energy distribution function of positive ions impinging on substrate in microwave plasmaRozdelovaci funkce iontu dopadajicich na substrat v mikrovlnnem plazmatuEnergy distribution functions of ions impinging on substrate in microwave plasm

    Theoretical evidence for the superluminality of evanescent modes

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    Though both theoretical and experimental investigations have revealed the superluminal behavior of evanescent electromagnetic waves, there are many disputes about the physical meaning and validity of such superluminal phenomenon, which is due to the fact that the traditional investigations are based on the theory of tunneling time, and concerned with the problem of what the group velocity of evanescent waves means. In this paper, by studying the quantum probability amplitude for photons to propagate over a spacelike interval along an undersized waveguide, we present theoretical evidence for such superluminality

    Flow resistance in skimming flow: a critical review

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    During very large rainfall events, dams and weirs must be equipped with adequate flood release facilities for a safe dissipation of the kinetic energy of the flow. With stepped spillway design, it is essential to predict accurately the flow resistance associated with the steps. The authors investigate the flow resistance of skimming flows and associated form losses. New experiments were performed with channel slopes ranging from 5.7 degrees up to 55 degrees. The results provide a better understanding of the basic flow patterns and flow resistance mechanisms. They emphasise that form loss is dominant. Altogether more than 35 model studies and 4 prototype investigations (totalising more than 650 data) are re-analysed
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