Eliminating the non-local effect in frequency-fixed probe wave based BOTDA sensor

2017 ◽  
Author(s):  
Sheng Wang ◽  
Zhisheng Yang ◽  
Xiaobin Hong ◽  
Wenqiao Lin ◽  
Jian Wu
Keyword(s):  
Local Effect ◽  
Probe Wave ◽  
Non Local

scholarly journals Author Correction: Non-local effect of impurity states on the exchange coupling mechanism in magnetic topological insulators

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Thiago R. F. Peixoto ◽  
Hendrik Bentmann ◽  
Philipp Rüßmann ◽  
Abdul-Vakhab Tcakaev ◽  
Martin Winnerlein ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Topological Insulators ◽  
Local Effect ◽  
Coupling Mechanism ◽  
Impurity States ◽  
Non Local

A Correction to this paper has been published: https://doi.org/10.1038/s41535-021-00314-9

Wave propagation in a non-local piezoelectric phononic crystal Timoshenko nanobeam

2020 ◽  
pp. 2150064
Author(s):  
Feiyang He ◽  
Denghui Qian ◽  
Musai Zhai
Keyword(s):  
Wave Propagation ◽  
Phononic Crystal ◽  
Local Effect ◽  
Geometric Parameters ◽  
Width Ratio ◽  
Plane Wave Expansion ◽  
Mechanical Coupling ◽  
Non Local ◽  
Influencing Parameters ◽  
Scale Coefficient

By applying non-local elasticity theory and plane wave expansion (PWE) method to Timoshenko beam, the calculation method of band structure of a non-local piezoelectric phononic crystal (PC) Timoshenko nanobeam is proposed and formulized. In order to investigate the properties of wave propagating in the nanobeam in detail, bandgaps of first four orders are picked, and the corresponding influence rules of thermo-electro-mechanical coupling fields, non-local effect and geometric parameters on bandgaps are studied. During the research works, temperature variation, external electrical voltage and axial force are chosen as the influencing parameters related to the thermo-electro-mechanical coupling fields. Scale coefficient is chosen as the influencing parameter corresponding to non-local effect. Length ratio between materials PZT-4 and epoxy and height-width ratio are chosen as the influencing parameters of geometric parameters. Moreover, all the band structures and influence rules of Timoshenko nanobeam are compared to those of Euler nanobeam. The results are expected to be of help for the design of micro and nanodevices based on piezoelectric periodic nanobeams.

scholarly journals Static and Dynamic Solutions of Functionally Graded Micro/Nanobeams under External Loads Using Non-Local Theory

Vibration ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 51-69
Author(s):  
Reza Moheimani ◽  
Hamid Dalir
Keyword(s):  
Power Index ◽  
Linear Equations ◽  
Local Effect ◽  
Functionally Graded ◽  
Local Theory ◽  
Classical Elasticity ◽  
Graded Materials ◽  
Nano Scale ◽  
Non Local ◽  
External Loads

Functionally graded materials (FGMs) have wide applications in different branches of engineering such as aerospace, mechanics, and biomechanics. Investigation of the mechanical behaviors of structures made of these materials has been performed widely using classical elasticity theories in micro/nano scale. In this research, static, dynamic and vibrational behaviors of functional micro and nanobeams were investigated using non-local theory. Governing linear equations of the problem were driven using non-local theory and solved using an analytical method for different boundary conditions. Effects of the axial load, the non-local parameter and the power index on the natural frequency of different boundary condition are assessed. Then, the obtained results were compared with those obtained from classical theory. These results showed that a non-local effect could greatly affect the behaviors of these beams, especially at nano scale.

ANALYTIC CONTINUATION OF OPERATORS APPLICATIONS: FROM NUMBER THEORY AND GROUP THEORY TO QUANTUM FIELD AND STRING THEORIES

1999 ◽  
Vol 11 (04) ◽  
pp. 463-501 ◽  
Author(s):  
S. C. WOON
Keyword(s):  
Number Theory ◽  
Analytic Continuation ◽  
Particle Physics ◽  
Fractional Derivatives ◽  
Bernoulli Polynomials ◽  
Local Effect ◽  
Quantum Field ◽  
Matrix Representations ◽  
Complex Power ◽  
Non Local

We are used to thinking of an operator acting once, twice, and so on. However, an operator can be analytically continued to the operator raised to a complex power. Applications include (s,r) diagrams and an extension of Fractional Calculus where commutativity of fractional derivatives is preserved, generating integrals and non-standard derivations of theorems in Number Theory, non-integer power series and breaking of Leibniz and Chain rules, pseudo-groups and symmetry deforming models in particle physics and cosmology, non-local effect in analytically continued matrix representations and its connection with noncommutative geometry, particle-physics-like scatterings of zeros of analytically continued Bernoulli polynomials, and analytic continuation of operators in QM, QFT and Strings.

scholarly journals Surface plasmon resonances of arbitrarily shaped nanometallic structures in the small-screening-length limit

2016 ◽  
Vol 472 (2191) ◽  
pp. 20160258 ◽  
Author(s):  
Ory Schnitzer ◽  
Vincenzo Giannini ◽  
Stefan A. Maier ◽  
Richard V. Craster
Keyword(s):  
Surface Plasmon ◽  
Local Effect ◽  
Coarse Grained ◽  
Local Response ◽  
Surface Plasmon Resonances ◽  
Screening Length ◽  
Local Description ◽  
Plasmon Resonances ◽  
Non Local ◽  
Non Locality

According to the hydrodynamic Drude model, surface plasmon resonances of metallic nanostructures blueshift owing to the non-local response of the metal’s electron gas. The screening length characterizing the non-local effect is often small relative to the overall dimensions of the metallic structure, which enables us to derive a coarse-grained non-local description using matched asymptotic expansions; a perturbation theory for the blueshifts of arbitrary-shaped nanometallic structures is then developed. The effect of non-locality is not always a perturbation and we present a detailed analysis of the ‘bonding’ modes of a dimer of nearly touching nanowires where the leading-order eigenfrequencies and eigenmode distributions are shown to be a renormalization of those predicted assuming a local metal permittivity.

scholarly journals Broadband impedance modulation via non-local acoustic metamaterials

2021 ◽  
Author(s):  
Zhiling Zhou ◽  
Sibo Huang ◽  
Dongting Li ◽  
Jie Zhu ◽  
Yong Li
Keyword(s):  
Frequency Band ◽  
Linear Time ◽  
Impedance Matching ◽  
Local Effect ◽  
Selective Absorption ◽  
Acoustic Metamaterials ◽  
Perfect Absorption ◽  
Impedance Modulation ◽  
Dual Functional ◽  
Non Local

Abstract Causality of linear time-invariant systems inherently defines the wave-matter interaction process in wave physics. This principle imposes strict constraints on the interfacial response of materials on various physical platforms. A typical consequence is that a delicate balance has to be struck between the conflicting bandwidth and geometric thickness when constructing a medium with desired impedance, which makes it challenging to realize broadband impedance modulation with compact structures. In pursue of improvement, the over-damped recipe and the reduced excessive response recipe are creatively presented in this work. As proof-of-concept demonstration, we construct a metamaterial with intensive mode density which supports strong non-locality over a frequency band from 320 Hz to 6400 Hz. Under the guidelines of the over-damped recipe and the reduced excessive response recipe, the metamaterial realizes impedance matching to air and exhibits broadband near-perfect absorption without evident impedance oscillation and absorption dips in the working frequency band. We further present a dual-functional design capable of frequency-selective absorption and reflection by concentrating the resonance modes in three frequency bands. Our research reveals the significance of the over-damped recipe and the strong non-local effect in broadband impedance modulation, which may open up avenues for constructing efficient artificial impedance boundaries for energy absorption and other wave manipulation.

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