Results 71 to 80 of about 1,214,457 (267)

Absorption of Broadband Low‐Frequency Sound Beyond the Thermodynamics Limit: An Acoustic Resonator With Magnetic Bearing

open access: yesAdvanced Science, EarlyView.
This work presents a magnetic‐bearing acoustic resonator that overcomes the thermodynamics limit of sound absorption. By introducing tunable negative stiffness, it achieves broadband low‐frequency absorption within a compact cavity, far exceeding the performance achievable by classic mass‐tuned designs.
Ying Hu   +5 more
wiley   +1 more source

Parabolic equations relative to vector fields

open access: yesElectronic Journal of Differential Equations, 2008
We define two notions of viscosity solutions to parabolic equations defined using vector fields, depending on whether the test functions concern only the past or both the past and the future. Using the parabolic maximum principle for vector fields, we
Thomas Bieske
doaj  

Classical and weak solutions of the partial differential equations associated with a class of two-point boundary value problems

open access: yesBoundary Value Problems, 2018
This paper is concerned with a kind of first-order quasilinear parabolic partial differential equations associated with a class of ordinary differential equations with two-point boundary value problems. We prove that the function given by the solution of
Ning Ma, Zhen Wu
doaj   +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

Revealing the Giant Electromechanical Effects in Yttria‐Stabilized Zirconia Single Crystal

open access: yesAdvanced Science, EarlyView.
Giant electromechanical responses are uncovered in yttria‐stabilized zirconia single crystal (SC‐YSZ), exhibiting pronounced orientation dependence. The giant electrostriction and piezoelectricity are directly correlated with the long‐range transport kinetics of oxygen vacancies.
Zhuwu Yi   +8 more
wiley   +1 more source

A cell complex structure for the space of heteroclines for a semilinear parabolic equation

open access: yesElectronic Journal of Differential Equations, 2009
It is well known that for many semilinear parabolic equations there is a global attractor which has a cell complex structure with finite dimensional cells.
Michael Robinson
doaj  

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