Tunnel effect elimination in multi-beam bathymetry sonar based on apFFT algorithm

Paraelectric resonance spectra of beryl crystals are observed in the X-band region between 5 and 20 kV/cm under the condition that the external electric field F[101̅0]. Additional dielectric measurements show, that the paraelectric centres are the monomeric water molecules in the beryl cavities. For water dipoles in beryl only two orientations of the molecular a-axis relative to the crystal C6-axis are possible, and only those with their a-axis parallel to the C6-axis contribute to the paraelectric resonance effect. The electric moment vector µ of these latter molecules may rotate in the (0001)-crystal plane, i. e. around their own a-axis, and has a value of (1.9 ± 0.2) D. A theoretical description of paraelectric resonance is presented for a simplified model: the electric dipoles have 6 equivalent equilibrium positions along the [101̅0]-directions, tunnel effect and external electric fields remove the site degeneracy and we observe a molecular Stark splitting. We calculate a value of (2.0 ± 0.4) GHz for the zero-field splitting in the one-parameter Hamiltonian model.

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Testing the tunnel effect: comparison, age and happiness in UK and German panels

IZA Journal of European Labor Studies ◽

10.1186/2193-9012-3-24 ◽

2014 ◽

Vol 3 (1) ◽

pp. 24 ◽

Cited By ~ 13

Author(s):

Felix R FitzRoy ◽

Michael A Nolan ◽

Max F Steinhardt ◽

David Ulph

Keyword(s):

Tunnel Effect

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Tunnel effect in GaInAsP/Inp double heterostructure diode

Electronics Letters ◽

10.1049/el:19880815 ◽

1988 ◽

Vol 24 (19) ◽

pp. 1200 ◽

Cited By ~ 1

Author(s):

T. Matsui ◽

K. Ohtsuka ◽

Y. Abe ◽

H. Ogata

Keyword(s):

Tunnel Effect ◽

Double Heterostructure

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Smart Ocean: A New Fast Deconvolved Beamforming Algorithm for Multibeam Sonar

Sensors ◽

10.3390/s18114013 ◽

2018 ◽

Vol 18 (11) ◽

pp. 4013 ◽

Cited By ~ 2

Author(s):

Jie Huang ◽

Tian Zhou ◽

Weidong Du ◽

Jiajun Shen ◽

Wanyuan Zhang

Keyword(s):

High Frequency ◽

Real Data ◽

Side Lobe ◽

Tunnel Effect ◽

Computation Complexity ◽

Acoustic Image ◽

Multibeam Sonar ◽

Sonar System ◽

Topographic Survey ◽

Beamforming Algorithm

A new fast deconvolved beamforming algorithm is proposed in this paper, and it can greatly reduce the computation complexity of the original Richardson–Lucy (R–L algorithm) deconvolution algorithm by utilizing the convolution theorem and the fast Fourier transform technique. This algorithm makes it possible for real-time high-resolution beamforming in a multibeam sonar system. This paper applies the new fast deconvolved beamforming algorithm to a high-frequency multibeam sonar system to obtain a high bearing resolution and low side lobe. In the sounding mode, it restrains the tunnel effect and makes the topographic survey more accurate. In the 2D acoustic image mode, it can obtain clear images, more details, and can better distinguish two close targets. Detailed implementation methods of the fast deconvolved beamforming are given, its computational complexity is analyzed, and its performance is evaluated with simulated and real data.

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Tunnel effect causing nonlinear current in few-layer graphene

Applied Physics Letters ◽

10.1063/1.4745206 ◽

2012 ◽

Vol 101 (6) ◽

pp. 063503 ◽

Cited By ~ 3

Author(s):

Quan Wang ◽

Jin Zhang ◽

Shouqi Yuan ◽

Xinxin Li

Keyword(s):

Tunnel Effect ◽

Layer Graphene ◽

Few Layer Graphene

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Mathematical analogies in physics. Thin-layer wave theory

Annals of Geophysics ◽

10.4401/ag-6324 ◽

2014 ◽

Vol 57 (1) ◽

Author(s):

José M. Carcione ◽

Vivian Grünhut ◽

Ana Osella

Keyword(s):

Quantum Mechanics ◽

Thin Layer ◽

Quantum Physics ◽

Constitutive Relations ◽

Normal Incidence ◽

Wave Theory ◽

Transverse Magnetic ◽

Momentum Conservation ◽

Tunnel Effect ◽

Basic Equations

<p>Field theory applies to elastodynamics, electromagnetism, quantum mechanics, gravitation and other similar fields of physics, where the basic equations describing the phenomenon are based on constitutive relations and balance equations. For instance, in elastodynamics, these are the stress-strain relations and the equations of momentum conservation (Euler-Newton law). In these cases, the same mathematical theory can be used, by establishing appropriate mathematical equivalences (or analogies) between material properties and field variables. For instance, the wave equation and the related mathematical developments can be used to describe anelastic and electromagnetic wave propagation, and are extensively used in quantum mechanics. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission) problem of a thin layer embedded between dissimilar media, considering the presence of anisotropy and attenuation/viscosity in the viscoelastic case, conductivity in the electromagnetic case and a potential barrier in quantum physics (the tunnel effect). The analogy is mainly illustrated with geophysical examples of propagation of S (shear), P (compressional), TM (transverse-magnetic) and TE (transverse-electric) waves. The tunnel effect is obtained as a special case of viscoelastic waves at normal incidence.</p>

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