scholarly journals Correcting Face Distortion in Wide-Angle Videos

2022 ◽  
Vol 31 ◽  
pp. 366-378
Wei-Sheng Lai ◽  
Yichang Shih ◽  
Chia-Kai Liang ◽  
Ming-Hsuan Yang
R. W. Carpenter ◽  
I.Y.T. Chan ◽  
J. M. Cowley

Wide-angle convergent beam shadow images(CBSI) exhibit several characteristic distortions resulting from spherical aberration. The most prominent is a circle of infinite magnification resulting from rays having equal values of a forming a cross-over on the optic axis at some distance before reaching the paraxial focal point. This distortion is called the tangential circle of infinite magnification; it can be used to align and stigmate a STEM and to determine Cs for the probe forming lens. A second distortion, the radial circle of infinite magnification, results from a cross-over on the lens caustic surface of rays with differing values of ∝a, also before the paraxial focal point of the lens.

L. T. Germinario ◽  
J. Blackwell ◽  
J. Frank

This report describes the use of digital correlation and averaging methods 1,2 for the reconstruction of high dose electron micrographs of the chitin-protein complex from Megarhyssa ovipositor. Electron microscopy of uranyl acetate stained insect cuticle has demonstrated a hexagonal array of unstained chitin monofibrils, 2.4−3.0 nm in diameter, in a stained protein matrix3,4. Optical diffraction Indicated a hexagonal lattice with a = 5.1-8.3 nm3 A particularly well ordered complex is found in the ovipositor of the ichneumon fly Megarhyssa: the small angle x-ray data gives a = 7.25 nm, and the wide angle pattern shows that the protein consists of subunits arranged in a 61 helix, with an axial repeat of 3.06 nm5.

1987 ◽  
Vol 32 (1) ◽  
pp. 54-55
Jack P. Shonkoff

2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

2019 ◽  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

2018 ◽  
pp. 11-13
Antonio De Rossi ◽  
Roberto Dini ◽  
Stefano Girodo

Given that this is the inaugural edition, we thought that the first issue of the international journal «ArchAlp» needed to be characterized by a wide angle view, taking shape as sort of veritable tour d’horizon of the alpine space. Thinking with the scientific committee of the journal, it seemed to us that a reflection on the characteristics of contemporary architectural production in the European Alpine area, starting from regionally-based analyses and interpretations, could be very important. A description of the state of the art, which in order to have scientific validity must be based on comparative interpretations, has the aim of restoring continuity and differences in the “building culture” among the various Alpine regions. From here the idea of building the central core around a series of local monographs.

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