Results 41 to 50 of about 241,664 (267)
On the Nonconvergence of Fourier Series [PDF]
Proceedings of the American Mathematical Society, 1958 and (ii)' an K log n/n, for some K>0, then the series (1.1), at t=0, converges. Wang [2] has also framed examples showing that k in condition (i) of Theorem A cannot be replaced by any k'
openaire +2 more sources
Advanced Functional Materials, EarlyView.Faradaic charging with bromine redox chemistry shows promise for energy storage, yet its efficient use in aqueous electrolytes is hindered by water decomposition and polybromides' cross‐diffusion, leading to suboptimal cell performance. This study introduces a tetrabutylammonium bromide‐based hydrated deep eutectic electrolyte with optimized water ...
Tae Pyeong Eom +4 more
wiley +1 more source
Classical Theory of Fourier Series:Demystified and Generalised [PDF]
arXiv, 2008 For a Riemann integrable function on an interval and for a point therein,we define 'Fourier series at the point on the interval' and bring out how and when the function element becomes expressible as Fourier series.In this process,we also generalise the theory by bringing in such concepts as finite Fourier series,right/left hand Fourier series.We also ...
arxiv
Convergence and Strong Summability of the Two-dimensional Vilenkin-Fourier Series [PDF]
arXiv, 2020 In this paper we investigate convergence and strong summability of the two-dimensional Vilenkin-Fourier series in the martingale Hardy spaces.
arxiv
Advanced Functional Materials, EarlyView.A novel polymer electrolyte membrane with a hyperbranched interpenetrating hydrogen bond network structure is developed. The unique structure of the hyperbranched polymer contributes to a high glass transition temperature exceeding 400 °C, enabling its operation at elevated temperatures for fuel cell applications.
Lingping Zeng +10 more
wiley +1 more source
Nonlinear Fourier Analysis [PDF]
arXiv, 2012 The nonlinear Fourier transform discussed in these notes is the map from the potential of a one dimensional discrete Dirac operator to the transmission and reflection coefficients thereof. Emphasis is on this being a nonlinear variant of the classical Fourier series, and on nonlinear analogues of classical analytic facts about Fourier series.
arxiv
A method for parameter hypothesis testing in nonparametric regression with Fourier series approach. [PDF]
MethodsX, 2023 Ramli M, Budiantara IN, Ratnasari V.
europepmc +1 more source
Interfacial Interaction‐Mediated Regulation of Metal Oxidation States for Enhanced CO2 Reduction
Advanced Functional Materials, EarlyView.A hybrid strategy is employed to optimize bismuth–oxygen interactions, precisely regulating interfacial bismuth–oxygen bonds during topochemical synthesis. This leads to vanadium oxynitride‐bismuth catalyst exhibiting high Faradaic efficiency and durability for formate production, attributed to enhanced reaction thermodynamics and kinetics.
Zhongyuan Ma +6 more
wiley +1 more source
Advanced Functional Materials, EarlyView.This study introduces a rapid, microwave‐assisted synthetic method for halide argyrodite solid‐state electrolytes Li6PS5X${\rm Li}_6 {\rm PS}_5X$ (X=$X =$ Cl−${\rm Cl}^-$, Br−${\rm Br}^-$, I−${\rm I}^-$). Microwave synthesis increases S2−${\rm S}^{2-}$/X−$X^-$ site disorder and rotational disorder of the isolated PS43−${{\mathrm{PS}}_{4}}^{3 ...
Austin M. Shotwell +4 more
wiley +1 more source
Convergence of multiple Fourier series of functions of bounded generalized variation [PDF]
arXiv, 2012 The paper introduces a new concept of $\Lambda $-variation of multivariable functions and investigates its connection with the convergence of multidimensional Fourier ...
arxiv