Vibration and control research of pipe penetration piece

The concealment capability of submarine is seriously restricted by the vibration of pipe penetration piece which is an important obstacle to the development of ‘quiet submarine’. In this paper, the characteristics and structures of pipe penetration piece are analyzed. Combining with domestic and foreign achievements, the active and passive methods of piping vibration reduction were introduced, and the measures of piping vibration isolation were elaborated. It provides reference for the vibration control of pipe penetration piece

Quantum theory of light diffraction

At present, the theory of light diffraction only has the simple wave-optical approach. In this paper, we study light diffraction with the approach of relativistic quantum theory. We find that the slit length, slit width, slit thickness and wave-length of light have affected to the diffraction intensity and form of diffraction pattern. However, the effect of slit thickness on the diffraction pattern can not be explained by wave-optical approach, and it can be explained in quantum theory. We compare the theoretical results with single and multiple slits experiment data, and find the theoretical results are accordance with the experiment data. Otherwise, we give some theory prediction. We think all the new prediction will be tested by the light diffraction experiment.Comment: 10 page

Kvantna teorija difrakcije neutrona na mnogo pukotina

We study neutron multiple-slit diffraction with a quantum mechanical approach. For the double-slit diffraction, we obtain the following results: (1) when the ratio (d + a)/a = n (n = 1, 2, 3, · · ·), orders n, 2n, 3n, · · · are missing in the diffraction pattern. (2) When the ratio of (d + a)/a /= n (n = 1, 2, 3, · · ·), there isn’t any missing order in the diffraction pattern. For diffraction on N (N ≥ 3) slits, we obtain the following results: (1) There are N − 2 secondary maxima and N − 1 minima between the two principle maxima. (2) As the slit number N increases, the diffraction intensity increases and the peak widths become narrower. (3) As the slit width increases, the diffraction intensity increases and the pattern width becomes narrower. (4) When the two-slit distance d increases, the number of principle maxima increases and the pattern becomes narrower. (5) We find a new quantum effect that the slit thickness c has a large effect to the multiple-slit diffraction pattern. We think all predictions in this work can be tested by neutron multiple-slit diffraction experiments.Proučavamo difrakciju neutrona na mnogo pukotina kvantno-mehaničkim pristupom. Za dvije pukotine postigli smo ove ishode računa: (1) Kada je omjer (d + a)/a = n (n = 1, 2, 3, · · ·), izostaju redovi n, 2n, 3n, · · · u difrakcijskoj slici. (2) Kada je (d + a)/a /= n (n = 1, 2, 3, · · ·), svi se redovi javljaju u difrakcijskoj slici. Za difrakciju na N (N ≥ 3) pukotina dobili smo ove ishode: (1) Između dva osnovna maksimuma javljaju se N − 2 sekundarna maksimuma i N − 1 minimuma. (2) Kako se broj pukotina povećava, povećava se intenzitet difrakcijske slike i širine vrhova se smanje. (3) Kad se širina pukotina poveća, pojača se intenzitet difrakcije a vrhovi se suze. (4) Ako se poveća razmak pukotina d, poveća se broj glavnih maksimuma i oni se suze. (5) Nalazimo nov kvantni efekt da duljina pukotina c ima velik utjecaj na difrakcijsku sliku u slučaju mnogo pukotina. Vjerujemo da će se ishodi ovog rada provjeriti mjerenjem neutronske difrakcije na rešetci s mnogo pukotina

Function Photonic Crystals

In the paper, we present a new kind of function photonic crystals, which refractive index is a function of space position. Unlike conventional PCs, which structure grow from two materials, A and B, with different dielectric constants $\epsilon_{A}$ and $\epsilon_{B}$. By Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we study the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals. By choosing various refractive index distribution function $n(z)$, we can obtain more width or more narrow band gap structure than conventional photonic crystals.Comment: 15 pages, 8 figures. arXiv admin note: text overlap with arXiv:1001.3793 by other authors; and text overlap with arXiv:1003.3524, arXiv:physics/0104088 by other authors without attributio