scholarly journals Flexible Broadband Terahertz Modulation Based on Strain-Sensitive MXene Material

2021 ◽  
Vol 9 ◽  
Author(s):  
Yangqi Liu ◽  
Xiang Li ◽  
Tingting Yang ◽  
Jingyu Liu ◽  
Bin Liu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Time Domain ◽  
Experimental Testing ◽  
Signal Transmission ◽  
Electrical Characterization ◽  
Terahertz Wave ◽  
Broadband Spectrum ◽  
The Time Domain ◽  
External Forces ◽  
Broadband Terahertz

A flexible broadband terahertz modulator based on a strain-sensitive MXene material is reported. MXene is shown to have high terahertz wave absorption through experimental testing of various substrate samples. Results show that the THz signal transmission increases with increasing stretching degree, which differs obviously from transmission through pure PVAc substrates. Analysis of the terahertz time-domain spectrum and electrical characterization indicate that the sample’s conductivity decreases with increasing stretching degree. The trend and magnitude of the electrical conductivity results are also very similar to those from the time-domain spectrum. MXene is shown to be a simple, efficient terahertz broadband spectrum modulator with transmittance that can be affected by applying external forces.

scholarly journals Rotation of the Rigid Earth

1997 ◽  
Vol 165 ◽  
pp. 295-300
Author(s):  
P. Bretagnon
Keyword(s):  
Time Domain ◽  
Time Span ◽  
Euler Angles ◽  
The Sun ◽  
The Moon ◽  
The Earth ◽  
Rigid Earth ◽  
The Time Domain ◽  
Tesseral Harmonics ◽  
External Forces

AbstractWe present the results of a solution of the Earth’s rotation built with analytical solutions of the planets and of the Moon’s motion. We take into account the influence of the Moon, the Sun and all the planets on the potential of the Earth for the zonal harmonics Cj,0 for j from 2 to 5, and also for the tesseral harmonics C2,2, S2,2C3,k, S3,k for k from 1 to 3 and C4,1, S4,1. We determine three Euler angles ψ, ω, and φ by calculating the components of the torque of the external forces with respect to the geocenter in the case of the rigid Earth. The analytical solution of the precession-nutation has been compared to a numerical integration over the time span 1900–2050. The differences do not exceed 16 μas for ψ and 8 μas for ω whereas the contribution of the tesseral harmonics reaches 150 μas in the time domain.

Objective-based equivalent static wind loads for long-span bridges

2019 ◽  
Author(s):  
Zachary J. Taylor ◽  
Pierre-Olivier Dallaire ◽  
Stoyan T. Stoyanoff
Keyword(s):  
Time Domain ◽  
Experimental Testing ◽  
Wind Loads ◽  
Response Analysis ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Equivalent Static Wind Loads ◽  
The Time Domain ◽  
Key Aspects

<p>The process to arrive at design wind loads for long-span bridges involves experimental testing and analytical methods. Time domain simulations are becoming increasingly common and many available studies demonstrate results of buffeting response analysis in the time domain. However, there is significantly more to the process than the response analysis to derive wind loads that can be applied practically for design. The current study focuses on two key aspects required to derive design wind loads: prediction of the peak modal deflection and derivation of modal combination coefficients using objective functions.</p>

In-Plane Thermal and Thermoelectric Properties of Polycrystalline Highly Preferred Orientation [(W)x(WSE2)y]z Superlattice Thin Films

2007 ◽  
Author(s):  
Anastassios Mavrokefalos ◽  
Ngoc T. Nguyen ◽  
Michael T. Pettes ◽  
David C. Johnson ◽  
Li Shi
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Time Domain ◽  
Preferred Orientation ◽  
Laser Reflectance ◽  
Thermoelectric Energy ◽  
Measurement Results ◽  
The Time Domain

It was recently found by using the time domain thermal reflectance method that polycrystalline highly preferred orientation WSe2 and [(W)x(WSe2)y]z superlattice films possess extremely low cross-plane thermal conductivity, which is desirable for thermal insulation and thermoelectric energy conversion applications. However, it is difficult to obtain the in-plane thermal conductivity by using the laser reflectance or the 3-ω method. Here we employ a suspended microdevice developed for measuring thermoelectric properties of individual nanowires and nanofilms to obtain the in-plane thermal conductivity, electrical conductivity, and Seebeck coefficient of [(W)x(WSe2)y]z superlattice films. The measurement results show that the in-plane thermal conductivities of these films are much higher than the cross-plane values, making the thermal conductivity of the films highly anisotropic.

Research on the Transmission Characteristics of FitzHugh-Nagumo Neuron

2014 ◽  
Vol 596 ◽  
pp. 413-416
Author(s):  
Guan Ping Wang ◽  
Wan Xia Yang ◽  
Sen Yang
Keyword(s):  
Time Domain ◽  
Noise Intensity ◽  
Signal Transmission ◽  
Gaussian White Noise ◽  
Model Neuron ◽  
Time Domain Analysis ◽  
Transmission Characteristics ◽  
External Excitation ◽  
Neuronal Signal ◽  
The Time Domain

The transmission characteristics of a FitzHugh-Nagumo (FHN) model neuron influenced by Gaussian white noise is studied in this work. With a sinusoidal stimulus as input, based on the time-domain analysis to the output , it is found that there are SR phenomenon, and the signal transmission is mainly depends on the noise intensity, the frequency and the amplitude of the external excitation signals. The analysis show that when the input frequency lies in 0.2Hz~0.5Hz and the amplitudeAis around 0.4, suitable noise intensity is conducive to the optimal neuronal signal transmission.

scholarly journals Programmable time-domain digital-coding metasurface for non-linear harmonic manipulation and new wireless communication systems

2018 ◽  
Vol 6 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Jie Zhao ◽  
Xi Yang ◽  
Jun Yan Dai ◽  
Qiang Cheng ◽  
Xiang Li ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Time Domain ◽  
Communication Systems ◽  
High Efficiency ◽  
Signal Transmission ◽  
Time Signal ◽  
Wireless Communication Systems ◽  
Diverse Range ◽  
Non Linear ◽  
The Time Domain

Abstract Optical non-linear phenomena are typically observed in natural materials interacting with light at high intensities, and they benefit a diverse range of applications from communication to sensing. However, controlling harmonic conversion with high efficiency and flexibility remains a major issue in modern optical and radio-frequency systems. Here, we introduce a dynamic time-domain digital-coding metasurface that enables efficient manipulation of spectral harmonic distribution. By dynamically modulating the local phase of the surface reflectivity, we achieve accurate control of different harmonics in a highly programmable and dynamic fashion, enabling unusual responses, such as velocity illusion. As a relevant application, we propose and realize a novel architecture for wireless communication systems based on the time-domain digital-coding metasurface, which largely simplifies the architecture of modern communication systems, at the same time yielding excellent performance for real-time signal transmission. The presented work, from new concept to new system, opens new pathways in the application of metamaterials to practical technology.

Apodisation in the time domain

1992 ◽  
Vol 2 (4) ◽  
pp. 615-620
Author(s):  
G. W. Series
Keyword(s):  
Time Domain ◽  
The Time Domain

JOINT INTERPRETATION OF AIRBORNE ELECTROMAGNETIC DATA IN THE TIME DOMAIN AND FREQUENCY DOMAIN

2018 ◽  
Vol 12 (7-8) ◽  
pp. 76-83
Author(s):  
E. V. KARSHAKOV ◽  
J. MOILANEN
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Time Domain ◽  
Frequency Interval ◽  
Single Spectrum ◽  
Simultaneous Inversion ◽  
Homogeneous Half Space ◽  
Time Domain Data ◽  
The Time Domain

Тhe advantage of combine processing of frequency domain and time domain data provided by the EQUATOR system is discussed. The heliborne complex has a towed transmitter, and, raised above it on the same cable a towed receiver. The excitation signal contains both pulsed and harmonic components. In fact, there are two independent transmitters operate in the system: one of them is a normal pulsed domain transmitter, with a half-sinusoidal pulse and a small "cut" on the falling edge, and the other one is a classical frequency domain transmitter at several specially selected frequencies. The received signal is first processed to a direct Fourier transform with high Q-factor detection at all significant frequencies. After that, in the spectral region, operations of converting the spectra of two sounding signals to a single spectrum of an ideal transmitter are performed. Than we do an inverse Fourier transform and return to the time domain. The detection of spectral components is done at a frequency band of several Hz, the receiver has the ability to perfectly suppress all sorts of extra-band noise. The detection bandwidth is several dozen times less the frequency interval between the harmonics, it turns out thatto achieve the same measurement quality of ground response without using out-of-band suppression you need several dozen times higher moment of airborne transmitting system. The data obtained from the model of a homogeneous half-space, a two-layered model, and a model of a horizontally layered medium is considered. A time-domain data makes it easier to detect a conductor in a relative insulator at greater depths. The data in the frequency domain gives more detailed information about subsurface. These conclusions are illustrated by the example of processing the survey data of the Republic of Rwanda in 2017. The simultaneous inversion of data in frequency domain and time domain can significantly improve the quality of interpretation.

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