Results 71 to 80 of about 55,665 (307)

Beyond Presumptions: Toward Mechanistic Clarity in Metal‐Free Carbon Catalysts for Electrochemical H2O2 Production via Data Science

open access: yesAdvanced Materials, EarlyView.
Metal‐free carbon catalysts enable the sustainable synthesis of hydrogen peroxide via two‐electron oxygen reduction; however, active site complexity continues to hinder reliable interpretation. This review critiques correlation‐based approaches and highlights the importance of orthogonal experimental designs, standardized catalyst passports ...
Dayu Zhu   +3 more
wiley   +1 more source

The merit of high-frequency data in portfolio allocation [PDF]

open access: yes, 2011
This paper addresses the open debate about the usefulness of high-frequency (HF) data in large-scale portfolio allocation. Daily covariances are estimated based on HF data of the S&P 500 universe employing a blocked realized kernel estimator.
Hautsch, Nikolaus   +5 more
core   +1 more source

Radar Target Detection Method of Aircraft Wake Vortices Based on Matrix Information Geometry

open access: yesLeida xuebao, 2017
The application of matrix information geometry to radar signal processing and target detection is a new and interesting subject. Wake vortices are Doppler-spread after Fourier transform.
Liu Junkai   +4 more
doaj   +1 more source

Microscopic Insights into Magnetic Warping and Time‐Reversal Symmetry Breaking in Topological Surface States of Rare‐Earth‐Doped Bi2Te3

open access: yesAdvanced Materials, EarlyView.
Magnetic doping of the topological insulator Bi2Te3 with erbium adatoms induces out‐of‐plane magnetism and breaks time‐reversal symmetry, opening a Dirac gap and driving a Fermi surface transition from hexagonal to star‐of‐David geometry. Microscopy, spectroscopy, and magnetic dichroism reveal atomically controlled magnetic interactions that tailor the
Beatriz Muñiz Cano   +18 more
wiley   +1 more source

AI–Guided 4D Printing of Carnivorous Plants–Inspired Microneedles for Accelerated Wound Healing

open access: yesAdvanced Materials, EarlyView.
This work presents an artificial intelligence (AI)‐guided 4D‐printed microneedle platform inspired by carnivorous plants for wound healing. A thermo‐responsive shape memory polymer enables body temperature–triggered self‐coiling for autonomous wound closure.
Hyun Lee   +21 more
wiley   +1 more source

Separable Covariance Matrices and Kronecker Approximation

open access: yesProcedia Computer Science, 2017
Abstract When a model structure allows for the error covariance matrix to be written in the form of the Kronecker product of two positive definite covariance matrices, the estimation of the relevant parameters is intuitive and easy to carry out. In many time series models, the covariance matrix does not have a separable structure.
Raja Velu, Kris Herman
openaire   +1 more source

Large‐Scale Determination of Frontier Orbital Energies of Disordered Small‐Molecule Organic Semiconductors Using Exciplex Emission Spectra

open access: yesAdvanced Materials, EarlyView.
ABSTRACT Accurately knowing the frontier orbital energies of the structurally disordered small‐molecule organic semiconductors that are used in optoelectronic devices such as organic light‐emitting diodes is required to rationally improve their performance. Here, we show that these energies can be deduced with a large accuracy from the peak energies of
Christian B. McDonald   +7 more
wiley   +1 more source

Universal correlations and power-law tails in financial covariance matrices

open access: yes, 2010
Signatures of universality are detected by comparing individual eigenvalue distributions and level spacings from financial covariance matrices to random matrix predictions.
Akemann, G   +5 more
core   +1 more source

Comments on the status of modern covariance data based on different fission and fusion reactor studies

open access: yesEPJ Nuclear Sciences & Technologies, 2018
Both the availability and the quality of covariance data improved over the last years and many recent cross-section evaluations, such as JENDL-4.0, ENDF/B-VII.1, JEFF-3.3, etc. include new covariance data compilations.
Kodeli Ivan
doaj   +1 more source

Ferroelectric Dynamic‐Field‐Driven Nucleation and Growth Model for Predictive Materials‐To‐Circuit Co‐Design

open access: yesAdvanced Materials, EarlyView.
This study presents a compact dynamic‐field‐driven nucleation and growth (DFNG) model that captures ferroelectric switching behavior under arbitrary voltage waveforms. It enables extraction of time‐dependent domain wall velocity and growth dimensionality, which can then be extended to device‐level modeling.
Yi Liang   +10 more
wiley   +1 more source

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