Results 41 to 50 of about 3,084,757 (296)

On the asymptotic Bieberbach conjecture

International Journal of Mathematics and Mathematical Sciences, 1982
The set S consists of complex functions f, univalent in the open unit disk, with f(0)=f'(0)-1=0. We use the asymptotic behavior of the positive semidefinite FitzGerald matrix to show that there is an absolute constant N0 such that, for any f(z)=z+?n ...
Mauriso Alves, Armando J. P. Cavalcante
doaj   +1 more source

Guanosine‐Quadruplex Hydrogels as Dynamic, Mechanically Tunable and Ion Conductive 3D Scaffolds for Cell Culture Applications

Advanced Functional Materials, EarlyView.
Versatile guanosine‐quadruplex (GQ) hydrogels are developed as dynamic biomatrices for cell culture. These scaffolds are fabricated under mild aqueous conditions, present improved stability, tunable mechanical properties within physiological ranges; fibrillar, porous microstructure, ion conductivity, and cytocompatibility.
Neha Thakur, Minye Jin, Pavel Milkin, Deepa Negi, Carla Cofiño Fabres, Hubert Gojzewski, Leonid Ionov, Alla Synytska, Andries van der Meer, Robert Passier, Julieta I. Paez   +10 more
wiley   +1 more source

Sharp Bounds for the Second Hankel Determinant of Logarithmic Coefficients for Strongly Starlike and Strongly Convex Functions

Axioms, 2022
The logarithmic coefficients are very essential in the problems of univalent functions theory. The importance of the logarithmic coefficients is due to the fact that the bounds on logarithmic coefficients of f can transfer to the Taylor coefficients of ...
Sevtap Sümer Eker, Bilal Şeker, Bilal Çekiç, Mugur Acu   +3 more
doaj   +1 more source

Voltage Gated Ion Entry Into Two‐dimensional Angstrom‐Scale Channels

Advanced Functional Materials, EarlyView.
We demonstrate voltage‐gated ion transport through artificial Å‐scale slit channels (∼4 Å high) formed by van der Waals assembly of 2D materials. At low electric fields, ions are excluded while water permeates. Above a threshold voltage, nonlinear hysteretic conduction emerges, driven by ion dehydration and concentration‐dependent barriers, mimicking ...
Solleti Goutham, Ashok Keerthi, Mohan T. Dronadula, Raj Kumar Gogoi, Hiran Jyothilal, Muhammad Sajeer Parambath, Alexander Rakowski, Sarah J. Haigh, Kalon Gopinadhan, Narayana R. Aluru, Boya Radha   +10 more
wiley   +1 more source

A Similarity Invariant and the Commutant of some Multiplication Operators on the Sobolev Disk Algebra

International Journal of Mathematics and Mathematical Sciences, 2012
Let R(𝔻) be the algebra generated in Sobolev space W22(𝔻) by the rational functions with poles outside the unit disk 𝔻¯. In this paper, we study the similarity invariant of the multiplication operators Mg in ℒ(R(𝔻)), when g is univalent analytic on 𝔻 or ...
Ruifang Zhao
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On Convex Univalent Functions with Convex Univalent Derivatives

Rocky Mountain Journal of Mathematics, 2005
The authors studied the functions \[ \sum_{k=0}^{\infty}a_{k}\dfrac{(1+z)^k}{k!}, \] for \(a_{0}\geq a_{1}\geq...\geq 0\). They showed that these functions are either constant or convex univalent in the unit disk \(D\). The work is inspired by \textit{T. J.
Ruscheweyh, Stephan, Salinas, Luis
openaire   +3 more sources

Dynamic Electrophoretic Assembly Coupled With Water‐Splitting‐Induced pH Control Enables Precision Ion Sieving Membranes

Advanced Materials, EarlyView.
A green, external‐catalyst‐free route grows defect‐free covalent organic framework membranes directly on ion‐exchange supports using an alternating electric field and in situ‐generated acid. Through a self‐regulating, self‐healing mechanism, the membranes achieve near‐complete, ultra‐fast separation of monovalent ions such as Li+, Na+, and K+, offering
Mohammad Hossein Jandaghian, Petric Marc Ruya, Ipek Ozyurt, Ali Atyabi, Samuel Eyley, Wim Thielemans, Alexander Volodin, Riccardo Alessandri, Xing Yang   +8 more
wiley   +1 more source

Multi‐Li+ Coordination for Superior Room‐Temperature Ionic Conductivity in PEO Solid Electrolytes

Advanced Materials, EarlyView.
A phosphonate‐functionalized polycarboxylate ether (P‐PCE) is introduced into PEO electrolytes to induce multi‐Li+ ions coordination, which effectively dissociates lithium salts, liberates Li+ from the strong chelation by PEO chains, and promotes fast Li+ hopping between adjacent coordination sites. Simultaneously, this design establishes dynamic, high‐
Hengming Yan, Bowen Zhang, Xuefan Liu, Lu Wang, Cunlong Hu, Anran Sheng, Congcong Zhang, Linglong Kong, Zhenzhen Wu, Yulin Zhong, Sheng Liu, Shanqing Zhang   +11 more
wiley   +1 more source

Simple proofs of certain inequalities with logarithmic coefficients of univalent functions

Researches in Mathematics
In this paper, we give simple proofs for the bounds (some of them sharp) of the difference of the moduli of the second and the first logarithmic coefficient for the general class of univalent functions and for the class of convex univalent functions.
M. Obradović, N. Tuneski
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Certain subclasses of bi-univalent functions associated with the Aghalary-Ebadian-Wang operator [PDF]

Sahand Communications in Mathematical Analysis, 2017
In this paper, we introduce and investigate two new subclasses of the functions class $ Sigma $ of bi-univalent functions defined in the open unit disk, which are associated with the Aghalary-Ebadian-Wang operator. We  estimate the coefficients $|a_{2} |$
Hamid Shojaei
doaj