Results 111 to 120 of about 81,306 (310)

Ultrafast Optoacoustics Reveals Intricate 3D Anisotropic Elasticity in Nanocrystalline Membranes

open access: yesAdvanced Science, EarlyView.
Ultrafast optoacoustic spectroscopy combined with a Sagnac interferometer enables non‐contact, simultaneous characterization of thickness and the full three‐dimensional anisotropic elastic constants in freestanding nanocrystalline copper membranes. By capturing gigahertz Lamb waves and zero‐group‐velocity resonances followed by SAFE‐GA inversion, the ...
Shuchang Zhang   +11 more
wiley   +1 more source

A Molten Salt Extraction Method for Palladium Recovery via the CaPd2 Intermetallic Compound

open access: yesAdvanced Science, EarlyView.
A designed Ca → CaPd2 → Pd pathway enables acid–free palladium recovery in molten salt. Calcium alloying forms anionic CaPd2, which is selectively oxidized by iodine from CaI2 to yield high–purity metallic Pd. ABSTRACT To address palladium scarcity and the low efficiency of conventional recovery processes, this work presents a molten–salt extraction ...
Jiapeng Zhang   +6 more
wiley   +1 more source

Generation and Enhancement of Persistent Nanoscale Magnetization in All‐Dielectric Metasurfaces by Optically Injected and Localized Free Carriers

open access: yesAdvanced Science, EarlyView.
Infrared metasurface‐guided waves (IR‐MGW) scattered by a time interface (TI) induced by rapid, localized free‐carrier generation can be efficiently rectified to generate strong, persistent magnetic fields. We develop a rigorous, theoretical model to study a time‐varying, dispersive medium and uncover the redistribution of the initial energy of the IR ...
Shivaksh Rawat   +2 more
wiley   +1 more source

Space‐Time Metasurface Antenna Enabled High‐Dimensional Electromagnetic Modulation for Intrinsic Physical Layer Security

open access: yesAdvanced Science, EarlyView.
The concept of high‐dimensional EM modulation using the STMA for physical layer secure communication is illustrated in figure. The STMA consists of a series of programmable unit cells, with 1‐bit reconfigurable phase states (0/π). The STMA is excited by a monochromatic continuous wave (CW) at frequency fc and controlled by a field‐programmable gate ...
Xinyu Fang   +6 more
wiley   +1 more source

Terahertz photons promote neuron growth and synapse formation through cAMP signaling pathway

open access: yesPhotoniX
Neurite outgrowth and synapse formation constitute the cellular basis for the establishment and plasticity of neural networks, crucially involved in cognitive functions. However, the techniques currently available to effectively and specifically modulate
Yuan Zhong   +6 more
doaj   +1 more source

Ultrafast Spin Dynamics of Pt/Gd19(Co0.8Fe0.2)81/Ta Heterostructure Investigated by Double-Pump Terahertz Emission Spectroscopy

open access: yesNanomaterials
Ultrafast spin dynamics is a core research focus for advancing ultrafast spintronic devices, yet its accurate quantitative probing remains a challenge with conventional time-resolved techniques.
Changwei Li   +6 more
doaj   +1 more source

Analysis of polarization diversity at terahertz frequencies

open access: yes, 2014
Terahertz frequencies offer the possibility of high resolution surveillance capabilities in areas requiring high levels of security. Terahertz imaging offers wavelengths providing high resolution with modest apertures while remaining able to penetrate ...
Nicholas P. Lawrence   +7 more
core   +1 more source

Hierarchical Physical‐Cyber Encryption via Metasurface‐Encoded Holographic Keys

open access: yesAdvanced Science, EarlyView.
ABSTRACT Physical‐layer encryption based on metasurfaces has emerged as a promising alternative to conventional algorithmic cryptography by embedding security into physical processes. However, most existing metasurface‐based encryption schemes operate within single‐stage or static frameworks, where correct physical illumination directly reveals the ...
Zhen Liu   +8 more
wiley   +1 more source

Ultrafast Nonequilibrium Carrier Dynamics in Topological Insulator Bi2Se3 Probed by Terahertz Spectroscopy at Room Temperature

open access: yesPhotonics
Topological insulators (TIs) feature unique Dirac fermion-hosting surface states with exceptional electronic properties, rendering them promising candidates for optoelectronic and spintronic applications. Herein, we investigate the relaxation dynamics of
Nuoxi Yu   +8 more
doaj   +1 more source

InGaN/GaN Distributed Feedback Laser Diodes with Surface Gratings and Sidewall Gratings

open access: yesMicromachines, 2019
A variety of potential applications such as visible light communications require laser sources with a narrow linewidth and a single wavelength emission in the blue light region. The gallium nitride (GaN)-based distributed feedback laser diode (DFB-LD) is
Zejia Deng   +4 more
doaj   +1 more source

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