scholarly journals A uniform dichotomy for generic ${\rm SL}(2,{\mathbb{R}})$ cocycles over a minimal base

2007 ◽  
Vol 135 (3) ◽  
pp. 407-417 ◽  
Author(s):  
Artur Avila ◽  
Jairo Bochi
2015 ◽  
Vol 144 (8) ◽  
pp. 3231-3242 ◽  
Author(s):  
Zoltán Halasi ◽  
Attila Maróti

2012 ◽  
Vol 626 ◽  
pp. 381-385
Author(s):  
Bao Hong Zhang ◽  
Yao Jin Wu ◽  
Zhi Min Zhang

This paper presents a case study of optimizing the forming process for a fan-shaped shell component. Numerical simulation was used to study the backward extrusion process of a fan-shaped shell. The underfill defect produced at the opening of the extruded shell due to the billet shape was solved and the minimal base thickness required to avoid the presence of the underfill defect at the bottom corner of the component was defined through the numerical simulation. The extrusion drawing and forming process of the fan-shaped shell were designed on the basis of the results of the numerical simulation. Forming experiments had been performed on the fan-shaped shell at 380 °C and cracking was found on the outside wall in the center of the extruded shell. Choked groove on the inner wall of the die and reducing the lubrication had been used to avoid the presence of cracking. The fan-shaped shell of AZ31 magnesium alloy has been successfully formed by the three-stage forming process of hot upsetting, hot backward extrusion and cold sizing.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yanlin Li ◽  
Akram Ali ◽  
Fatemah Mofarreh ◽  
Nadia Alluhaibi

In this paper, we show that if the Laplacian and gradient of the warping function of a compact warped product submanifold Ω p + q in the hyperbolic space ℍ m − 1 satisfy various extrinsic restrictions, then Ω p + q has no stable integral currents, and its homology groups are trivial. Also, we prove that the fundamental group π 1 Ω p + q is trivial. The restrictions are also extended to the eigenvalues of the warped function, the integral Ricci curvature, and the Hessian tensor. The results obtained in the present paper can be considered as generalizations of the Fu–Xu theorem in the framework of the compact warped product submanifold which has the minimal base manifold in the corresponding ambient manifolds.


2020 ◽  
Vol 174 (2) ◽  
pp. 167-183
Author(s):  
Yidong Lin ◽  
Jinjin Li ◽  
Liangxue Peng ◽  
Ziqin Feng

Author(s):  
Benjamin Sambale

AbstractMotivated by recent results on the minimal base of a permutation group, we introduce a new local invariant attached to arbitrary finite groups. More precisely, a subset $$\Delta $$ Δ of a finite group G is called a p-base (where p is a prime) if $$\langle \Delta \rangle $$ ⟨ Δ ⟩ is a p-group and $$\mathrm {C}_G(\Delta )$$ C G ( Δ ) is p-nilpotent. Building on results of Halasi–Maróti, we prove that p-solvable groups possess p-bases of size 3 for every prime p. For other prominent groups, we exhibit p-bases of size 2. In fact, we conjecture the existence of p-bases of size 2 for every finite group. Finally, the notion of p-bases is generalized to blocks and fusion systems.


PEDIATRICS ◽  
1978 ◽  
Vol 61 (4) ◽  
pp. 663-664
Author(s):  
Nicholas M. Nenson

Three circumstances may (thinly) be argued to qualify the present writer as an "expert" commentator on the article by Kelly et al. in this issue of Pediatrics (p. 511): first (and nearly 20 years ago), that most humbling of all experiences for the pediatrician, the dismissal from one's office of an apparently healthy 2-month-old infant with a minor upper respiratory tract infection who is brought dead on arrival to one's own hospital not three hours later, the unavailability of any autopsy data (difficult to obtain from unsubsidized pathologists in small suburban hospitals ruled by the coroner system of forensic medicine) forcing the diagnosis of sudden infant death syndrome (SIDS) on bewildered parents and shaken physician; last, participation in a recent task force assembled by the American Academy of Pediatrics in an attempt to generate an omniscient statement to cover the optimal management of a dreaded condition ("near-miss SIDS") whose identification is by definition uncertain and concerning which a minimal base of factual knowledge is only now beginning to accrue.


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