Results 131 to 140 of about 4,863,781 (309)

Electrolyte–Framework Matching in High‐Voltage TEMPO‐COF Cathodes for Lithium Batteries

Advanced Science, EarlyView.
TEMPO‐functionalized covalent organic frameworks are investigated as high‐voltage cathodes for lithium batteries. Screening five electrolyte anions identifies lithium difluoro(oxalato)borate (LiDFOB) as the optimal electrolyte, balancing capacity, rate capability, and cycling stability, while buckypaper electrodes achieve high mass loading (40 mg cm−2)
Marilyn Esclance DMello, Nagaraj Patil, Fanni Fekecs, Sergio Pinilla, Rebeca Marcilla, Manuel Souto   +5 more
wiley   +1 more source

Polarization Dynamics in Ferroelectrics: Insights Enabled by Machine Learning Molecular Dynamics

Advanced Science, EarlyView.
Machine learning molecular dynamics is presented as a route to capture polarization switching, domain wall kinetics, topological polar textures, and polar mechanical coupling beyond the limits of conventional atomistic methods. This Perspective surveys recent progress and identifies key methodological directions, including long‐range electrostatics ...
Dongyu Bai, Ri He, Junxian Liu, Liangzhi Kou   +3 more
wiley   +1 more source

Probabilistic Allocation of Payload Code Rate and Header Copies in LR-FHSS Networks

IEEE Access
We evaluate the performance of the LoRaWAN Long-Range Frequency Hopping Spread Spectrum (LR-FHSS) technique using a device-level probabilistic strategy for code rate and header replica allocation.
Jamil de Araujo Farhat, Jean Michel de Souza Sant'Ana, Joao Luiz Rebelatto, Nurul Huda Mahmood, Gianni Pasolini, Richard Demo Souza   +5 more
doaj   +1 more source

Halide Perovskite: A Rich Source of Thermal Insulator

Advanced Science, EarlyView.
Halide perovskites exhibit ultralow thermal conductivity driven by intrinsic lattice softness and strong anharmonicity, falling below conventional defect‐engineering limits. Weak metavalent bonding, A‐site rattling, and dynamic octahedral tilting drive phonon scattering to the Ioffe–Regel limit, where wave‐like tunneling replaces particle‐like ...
Haolin Ye, Bangzhi Ge, Yuan Yu, Chongjian Zhou   +3 more
wiley   +1 more source

Bipolar Palladium Membrane Enabling Crossover‐Free Selective Proton Transport

Advanced Science, EarlyView.
This study introduces a crossover‐free bipolar palladium membrane that transports protons selectively via reversible Pd/PdHx absorption–desorption and lattice hydrogen diffusion, overcoming the conductivity–selectivity trade‐off of polymer membranes. It enables water‐fed Li‐mediated ammonia synthesis, achieving 51% Faradaic efficiency and stable 12 h ...
Jiyeon Baek, Yeongbae Jeon, Seunga Lee, Ahee Choi, Joonmok Shim, Kyungho Lee, Ho Woun Jung, Sun Hyung Kim, Churl Hee Cho, Hyung Chul Yoon, Yun Jeong Hwang, Jae Hyung Kim   +11 more
wiley   +1 more source

Application study of Costas arrays in multiuser radar systems

Tongxin xuebao, 2010
The construction and performance of frequency hopping codes were discussed but the emphasis was laid on the construction of Costas arrays.The frequency hopping codes called Costas arrays could be designed to have almost ideal auto-ambiguity and good ...
YAO Jian-guo1, HUANG Qing2
doaj   +2 more sources

Anisotropic Memristive Switching in NbOCl2 Enabled by Directional Oxygen Ion Migration

Advanced Science, EarlyView.
This study investigates strongly orientation‐dependent memristive switching in anisotropic NbOCl2, observed exclusively along the in‐plane c‐axis. The switching originates from direction‐selective oxygen‐ion migration and vacancy propagation that modulate the Pd/NbOCl2 Schottky barrier, enabling short‐term plasticity.
Caokun Wang, Yun Ji, Sanchali Mitra, Yufei Shi, Haofei Zheng, Yee Sin Ang, Kah‐Wee Ang   +6 more
wiley   +1 more source

Efficient Hot Carrier Management in Lead Halide Perovskite Micro‐Disks Revealed by Super‐Diffusive Migration

Advanced Science, EarlyView.
Hot‐carrier transport in metal halide perovskites is investigated using spatiotemporally‐resolved photoluminescence microscopy. Mesa‐shaped MAPbBr3 microdisks exhibit anomalous super‐diffusive carrier propagation on nanosecond timescales, driven by hot‐carrier stabilization and strong carrier–phonon coupling.
Nithin Pathoor, Shun Omagari, Martin Vacha   +2 more
wiley   +1 more source

Performance Evaluation of Distributed-Antenna Communications Systems Using Beam-Hopping

, 2005
Digital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference, especially, in the direction of the transmitted beams ...
Yang, L.-L., Zhu, J., Hu, H.
core   +1 more source

Frequency-hopping spread spectrum (FHSS) simulation

, 2015
This graduate project focuses on a frequency hopping spread spectrum (FHSS) communication system between a transmitter and a receiver in the presence of a jammer. It further describes the method used to employ frequency hopping to successfully transmit a
Lutfi, Michael A
core