Results 81 to 90 of about 27,914 (184)

Sub‐100 Nanometer Focusing of Hard X‐rays Using SU‐8 Compound Kinoform Focusing Lenses

Advanced Photonics Research, Volume 7, Issue 4, April 2026.
A novel aberration‐free X‐ray compound refractive lens design based on Cartesian oval curve is presented. Achieving a vertical focal spot size of 70.8 nm using knife‐edge scanning with a 200 μm incident aperture. Wavefront reconstruction via knife‐edge imaging further resolves a refined focal spot of 56 nm.
Yuanze Xu, Vishal Dhamgaye, Hongchang Wang, Oliver Fox, Futing Yi, Ming Li, Weiwei Zhang, Junliang Yang, David Laundy, Dongni Zhang, Kawal Sawhney, Jing Liu, He Lin   +12 more
wiley   +1 more source

Optical excitation of nonlinear spin waves

, 2010
We demonstrate a technique for exciting spin waves in an ultracold gas of Rb-87 atoms based on tunable AC Stark potentials. This technique allows us to excite normal modes of spin waves with arbitrary amplitudes in the trapped gas, including dipole ...
Bashkin E P, J M McGuirk, L F Zajiczek
core   +1 more source

Upsampling DINOv2 Features for Unsupervised Vision Tasks and Weakly Supervised Materials Segmentation

Advanced Intelligent Systems, Volume 8, Issue 4, April 2026.
Feature from recent image foundation models (DINOv2) are useful for vision tasks (segmentation, object localization) with little or no human input. Once upsampled, they can be used for weakly supervised micrograph segmentation, achieving strong results when compared to classical features (blurs, edge detection) across a range of material systems.
Ronan Docherty, Antonis Vamvakeros, Samuel J. Cooper   +2 more
wiley   +1 more source

Chemoselective Alkylating Esterification of Thiophosphinic Acids: An Experimental and Theoretical Study

ChemPlusChem, Volume 91, Issue 4, April 2026.
The esterification of thiophosphinic acids with haloalkanes was found to be S‐selective providing only the corresponding thiolic esters. The kinetic selectivity was confirmed by theoretical calculations exploring the mechanism in the presence of triethylamine as the base.
György Keglevich, Dorka Nagy, Zoltán Mucsi, Konstantin Karaghiosoff, Mátyás Czugler, László Drahos, Gömöry Ágnes   +6 more
wiley   +1 more source

Reduced sediment accumulation rate enhances early marine diagenesis of periplatform sediments

The Depositional Record, Volume 12, Issue 2, April 2026.
The influence of reduced sediment accumulation rate on early marine burial diagenesis was investigated in sediments collected by ODP Leg 133. Results show that low sediment accumulation rates can produce substantial and asynchronous shifts in stable carbon isotope ratios across a slope transect without the development of sedimentological indicators of ...
Amanda M. Oehlert, Larry C. Peterson, Dick Kroon, Peter K. Swart   +3 more
wiley   +1 more source

Some algorithms for investigating the multiplicity of the invariant line at the infinity for quartic differential systems

, 2020
Multiplicitatea liniilor drepte invariante pentru sistemele diferențiale polinomiale joacă un rol cheie în integrabilitate [1], stabilitatea sistemului, existența ciclurilor limită, probleme de centru etc. Există definiții pentru diferite tipuri de multiplicități de linii drepte invariante.
Repeşco, V.F., Josan, D.
openaire   +1 more source

Microstructure and Performance Optimization of Barley Husk Ash–Blended Mortars: A Sustainable Approach to Cement Substitution

Engineering Reports, Volume 8, Issue 4, April 2026.
Barley husk ash (BHA), an agricultural byproduct rich in pozzolanic oxides, was optimized as a sustainable cement substitute. Statistical modeling and experimental validation confirmed 22.75% BHA as the optimal replacement, enhancing mechanical and durability performance while advancing eco‐efficient construction practices.
Behailu Zerihun Hailemariam, Woubishet Zewdu Taffese, Duy‐Hai Vo, Mitiku Damtie Yehualaw   +3 more
wiley   +1 more source

EVSS‐Based Simulation Techniques for the Viscoelastic Fluids With Pure Polymer Melts Using Three‐Field Approach

International Journal for Numerical Methods in Fluids, Volume 98, Issue 4, Page 492-509, April 2026.
This paper presents a finite element method for simulating highly viscoelastic flows of pure polymer melts using the Elastic Viscous Stress Splitting formulation. The method avoids higher‐order derivatives in the weak formulation by reformulating the convective term in the constitutive equation.
R. Ahmad, P. Zajac, S. Turek
wiley   +1 more source

Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the String‐Theoretical Swampland Programme

Fortschritte der Physik, Volume 74, Issue 4, April 2026.
Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley   +1 more source

Tessellation Groups, Harmonic Analysis on Non‐Compact Symmetric Spaces and the Heat Kernel in View of Cartan Convolutional Neural networks

Fortschritte der Physik, Volume 74, Issue 4, April 2026.
ABSTRACT In this paper, we continue the development of the Cartan neural networks programme, launched with three previous publications, by focusing on some mathematical foundational aspects that we deem necessary for our next steps forward. The mathematical and conceptual results are diverse and span various mathematical fields, but the inspiring ...
Pietro Fré, Federico Milanesio, Marcelo Oyarzo, Matteo Santoro, Mario Trigiante   +4 more
wiley   +1 more source