Large-angle two-dimensional grating with hybrid mechanisms

2021 ◽  
Vol 46 (4) ◽  
pp. 920
Author(s):  
Junyu Zou ◽  
Ziqian He ◽  
Qian Yang ◽  
Kun Yin ◽  
Kun Li ◽  
...  
Keyword(s):  
Large Angle ◽  
Two Dimensional ◽  
Hybrid Mechanisms

scholarly journals Results of inverse synthesis of two-dimensional radar images of objects with autofocusing in wide sectors of angles.

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
S.I. Moryakov ◽  
◽  
S.M. Nesterov ◽  
I.A. Skorodumov ◽  
◽  
...  
Keyword(s):  
High Resolution ◽  
Synthetic Aperture Radar ◽  
Large Angle ◽  
Synthetic Aperture ◽  
Synthetic Image ◽  
Wide Angle ◽  
Two Dimensional ◽  
Radar Images ◽  
Radar Systems ◽  
Wideband Radar

Modern wideband radar systems makes possible to obtain high resolution inverse synthetic aperture radar images of objects. One of the difficult actual approaches in radar test facilities is wide angle autofocusing processing. This paper proposed a recommendations to wide angle (above 10 degrees) inverse synthetic image autofocusing processing based on dividing a large angle sector into several small sections. Also proposed an experimental results of autofocusing processing in 30° and 60° angle sector.

An Experimental Investigation of Cavitation Inception and Development on a Two-Dimensional Eppler Hydrofoil

1999 ◽  
Vol 122 (1) ◽  
pp. 164-173 ◽  
Author(s):  
J.-A. Astolfi ◽  
P. Dorange ◽  
J.-Y. Billard ◽  
I. Cid Tomas
Keyword(s):  
Reverse Flow ◽  
Pressure Coefficient ◽  
Large Angle ◽  
Separated Flow ◽  
Leading Edge ◽  
Angle Of Incidence ◽  
Two Dimensional ◽  
Velocity Measurements ◽  
Cavitation Inception ◽  
Minimum Pressure

Cavitation inception and development on a two-dimensional foil with an Eppler E817 cross section issued from an inverse calculus have been experimentally investigated. The foil is theoretically designed to have a wide cavitation-free bucket allowing a large range of cavitation-free angle of incidence (Eppler, R., 1990, Airfoil Design and Data, Springer-Verlag, Berlin). The inception cavitation numbers, the noise level, the velocity distribution, the minimum pressure coefficient, the cavitation patterns (bubble, leading edge “band type” cavitation, attached sheet cavity), together with the sheet cavity length have been experimentally determined. Effects on the velocity field have been studied too with a slightly developed cavitation. For angles of incidence larger than 1 deg, a great difference exists between the inception cavitation number and the theoretical minimum pressure coefficient. However it is in agreement with the measured one obtained from velocity measurements (for 0 deg<α<6 deg). Discrepancy between theory and experiment on scale models is generally attributed to a flow separation at the leading edge. Although there are some indications of a separated flow at the leading edge, the velocity measurements do not show reverse flow with clearly detected negative velocities excepted for a large angle of incidence equal to 10 deg. Concerning sheet cavity development, the length cavity is found to scale as [σ/2α−αiσ]−m with m close to 2, for length cavities that do not exceed half the foil chord and for σ/2α−αiσ larger than about 30. [S0098-2202(00)00201-7]

Large angle and high linearity two-dimensional laser scanner based on voice coil actuators

2011 ◽  
Vol 82 (10) ◽  
pp. 105103 ◽  
Author(s):  
Xin Wu ◽  
Sihai Chen ◽  
Wei Chen ◽  
Minghui Yang ◽  
Wen Fu
Keyword(s):  
Large Angle ◽  
Laser Scanner ◽  
Two Dimensional ◽  
High Linearity

Broadband large-angle self-collimation in two-dimensional silicon photonic crystal

2012 ◽  
Vol 37 (12) ◽  
pp. 2412 ◽  
Author(s):  
Lin Gan ◽  
Fei Qin ◽  
Zhi-Yuan Li
Keyword(s):  
Photonic Crystal ◽  
Large Angle ◽  
Two Dimensional ◽  
Silicon Photonic

Two-dimensional Large-angle Scanning Optical Phased Array with Single Wavelength Beam

2019 ◽  
Author(s):  
Pengfei Wang ◽  
Guangzhen Luo ◽  
Yajie Li ◽  
Mengqi Wang ◽  
Fangyuan Meng ◽  
...  
Keyword(s):  
Phased Array ◽  
Large Angle ◽  
Two Dimensional ◽  
Optical Phased Array

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Analysis of the 9th November 1990 flare

2000 ◽  
Vol 179 ◽  
pp. 229-232
Author(s):  
Anita Joshi ◽  
Wahab Uddin
Keyword(s):  
Image Processing ◽  
Two Dimensional ◽  
Temporal Behaviour ◽  
Contour Maps ◽  
Dimensional Measurements ◽  
Processing Software ◽  
Image Processing Software

AbstractIn this paper we present complete two-dimensional measurements of the observed brightness of the 9th November 1990Hαflare, using a PDS microdensitometer scanner and image processing software MIDAS. The resulting isophotal contour maps, were used to describe morphological-cum-temporal behaviour of the flare and also the kernels of the flare. Correlation of theHαflare with SXR and MW radiations were also studied.

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