scholarly journals Characterizing domains by the limit set of their automorphism group

2017 ◽  
Vol 308 ◽  
pp. 438-482 ◽  
Author(s):  
Andrew M. Zimmer
Keyword(s):  
Author(s):  
A. Olsen ◽  
J.C.H. Spence ◽  
P. Petroff

Since the point resolution of the JEOL 200CX electron microscope is up = 2.6Å it is not possible to obtain a true structure image of any of the III-V or elemental semiconductors with this machine. Since the information resolution limit set by electronic instability (1) u0 = (2/πλΔ)½ = 1.4Å for Δ = 50Å, it is however possible to obtain, by choice of focus and thickness, clear lattice images both resembling (see figure 2(b)), and not resembling, the true crystal structure (see (2) for an example of a Fourier image which is structurally incorrect). The crucial difficulty in using the information between Up and u0 is the fractional accuracy with which Af and Cs must be determined, and these accuracies Δff/4Δf = (2λu2Δf)-1 and ΔCS/CS = (λ3u4Cs)-1 (for a π/4 phase change, Δff the Fourier image period) are strongly dependent on spatial frequency u. Note that ΔCs(up)/Cs ≈ 10%, independent of CS and λ. Note also that the number n of identical high contrast spurious Fourier images within the depth of field Δz = (αu)-1 (α beam divergence) decreases with increasing high voltage, since n = 2Δz/Δff = θ/α = λu/α (θ the scattering angle). Thus image matching becomes easier in semiconductors at higher voltage because there are fewer high contrast identical images in any focal series.


2017 ◽  
Vol 68 (9) ◽  
pp. 2092-2097
Author(s):  
Catalina Calin ◽  
Gina Vasile Scaeteanu ◽  
Roxana Maria Madjar ◽  
Otilia Cangea

Metallic ions present a great importance in oenological practice and usually are present in wines in levels that are not hazardous. Among all metallic ions, zinc presents a great interest because may cause the persistence of the wine sour taste and by the side of Al, Cu, Fe and Ni, contribute to the haze formation and the change of color. The present study was focused on measuring the concentration levels of mobile zinc from vineyard soil before and after phytosanitary treatments and zinc content from white (Feteasca Alba - FA, Riesling Italian - RI, Sauvignon Blanc - SB, Tamaioasa Rom�neasca - TR), rose (Busuioaca de Bohotin - BB) and red (Feteasca Neagra - FN) wines within the wine-growing Tohani area, Romania. Other objective was to investigate of the influence of crop year and variety on zinc levels found in wine samples. Mobile zinc content for all analyzed soil samples is low ([1.5 mg/kg). Analyses indicated that zinc content found in wines was below 5 mg/L, limit set by Organisation Internationale of Vine and Wine (OIV). Also, it was found that red wines contain zinc in higher concentrations than white ones.


2009 ◽  
Vol 71 (7-8) ◽  
pp. 2834-2839
Author(s):  
Bin-Guo Wang ◽  
Wan-Tong Li

2019 ◽  
Vol 31 (1) ◽  
pp. 265-273
Author(s):  
Fabio Podestà ◽  
Alberto Raffero

Abstract We prove that the automorphism group of a compact 6-manifold M endowed with a symplectic half-flat {\mathrm{SU}(3)} -structure has Abelian Lie algebra with dimension bounded by {\min\{5,b_{1}(M)\}} . Moreover, we study the properties of the automorphism group action and we discuss relevant examples. In particular, we provide new complete examples on {T\mathbb{S}^{3}} which are invariant under a cohomogeneity one action of {\mathrm{SO}(4)} .


Author(s):  
HUA HAN ◽  
HONG CI LIAO ◽  
ZAI PING LU
Keyword(s):  

Abstract A graph is edge-primitive if its automorphism group acts primitively on the edge set, and $2$ -arc-transitive if its automorphism group acts transitively on the set of $2$ -arcs. In this paper, we present a classification for those edge-primitive graphs that are $2$ -arc-transitive and have soluble edge-stabilizers.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Alexander Perepechko

AbstractLet Y be a smooth del Pezzo surface of degree 3 polarized by a very ample divisor that is not proportional to the anticanonical one. Then the affine cone over Y is flexible in codimension one. Equivalently, such a cone has an open subset with an infinitely transitive action of the special automorphism group on it.


2021 ◽  
pp. 1-11
Author(s):  
STEPHEN JACKSON ◽  
BILL MANCE ◽  
SAMUEL ROTH

Abstract We consider the complexity of special $\alpha $ -limit sets, a kind of backward limit set for non-invertible dynamical systems. We show that these sets are always analytic, but not necessarily Borel, even in the case of a surjective map on the unit square. This answers a question posed by Kolyada, Misiurewicz, and Snoha.


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