- 标题
- 摘要
- 关键词
- 实验方案
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Structural and electrical properties of copper doped In<sub>2</sub>O<sub>3</sub> nanostructures prepared by citrate gel processes
摘要： Copper doped indium oxide (In2?xCuxO3) nanostructures were prepared by a simple citrate gel process using indium nitrate and copper nitrate as precursors. The influence of the dopant concentration (x = 0, 0.03, 0.05 and 0.07) on the structural, morphological and the electrical properties of indium oxide was studied. The crystallite size and the surface roughness (root mean square roughness and the mean roughness) of the prepared samples increased as a function of the dopant concentration. However, the copper (Cu) concentration did not affect the basic host crystal structure. The prepared samples showed an n-type semiconducting behavior and a variation in the electrical parameters, which might be due to the confinement of the electronic states of the dopants to small volumes (less than 100 nm). Implication of the degenerate electron gas model to the experimental electrical data revealed the role of the different scattering centers in conduction electron scattering.
关键词： Indium oxide,Mean free path,Electron gas model,Citrate gel route
更新于2025-09-23 15:23:52
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Monolayer transition metal dichalcogenides in strong magnetic fields: Validating the Wannier model using a microscopic calculation
摘要： Using an equation of motion (EOM) approach, we calculate excitonic properties of monolayer transition metal dichalcogenides perturbed by an external magnetic field. We compare our findings to the widely used Wannier model for excitons in two-dimensional materials and to recent experimental results. We find good agreement between the calculated excitonic transition energies and the experimental results. In addition, we find that the exciton energies calculated using the EOM approach are slightly lower than the ones calculated using the Wannier model. Finally, we also show that the effect of the dielectric environment on the magnetoexciton transition energy is minimal due to counteracting changes in the exciton energy and the exchange self-energy correction.
关键词： monolayer transition metal dichalcogenides,magnetic field,Wannier model,excitons,magnetoexcitons,equation of motion
更新于2025-09-23 15:23:52
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Charge transport in graphene-based mesoscopic realizations of Sachdev-Ye-Kitaev models
摘要： We consider a recent proposal for a physical realization of the Sachdev-Ye-Kitaev (SYK) model in the zeroth-Landau-level sector of an irregularly shaped graphene flake. We study in detail charge transport signatures of the unique non-Fermi-liquid state of such a quantum dot coupled to noninteracting leads. The properties of this setup depend essentially on the ratio p between the number of transverse modes in the lead M and the number of the fermion degrees of freedom N on the SYK dot. This ratio can be tuned via the magnetic field applied to the dot. Our proposed setup gives access to the nontrivial conformal-invariant regime associated with the SYK model as well as a more conventional Fermi-liquid regime via tuning the field. The dimensionless linear-response conductance acquires distinct p dependencies for the two phases, respectively, in the low-temperature limit, with a universal jump at the transition. We find that corrections scale linearly and quadratically in either temperature or frequency on the two sides of the transition. In the weak-tunneling regime, we find differential conductance proportional to the inverse square root of the applied voltage bias U for bias energy eU larger than temperature scale kB T. This dependence is replaced by a conventional Ohmic behavior with constant conductance proportional to 1/sqrt(T) for bias energy eU smaller than temperature scale kB T. We also describe the out-of-equilibrium current-bias characteristics and discuss various crossovers between the limiting behaviors mentioned above.
关键词： Sachdev-Ye-Kitaev model,tunneling conductance,graphene,quantum dot,charge transport,non-Fermi-liquid,conformal invariance
更新于2025-09-23 15:23:52
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Distributed Small-signal Equivalent Circuit Model and Parameter Extraction for SiGe HBT
摘要： In this paper, we present an improved high frequency small-signal distributed model for SiGe HBTs under forward-active mode based on the transmission line theory. The distributed nature of the transistor structure is taken into account in the proposed model. The single SiGe HBT is considered to be a cascade of many infinitesimal transistors, connected with the intrinsic base resistance. The closed-form solutions of admittance parameters for the distributed model are derived by solving the transmission line equation. With reasonable approximation and simplification, the model parameters are then directly extracted based on the nonlinear rational function fitting. The new improved distributed model and parameter extraction technique are validated with a 1×1.2×30 μm2 SiGe HBT from 100 MHz to 20.89 GHz. The simulated S-parameters in the proposed transmission line model are in close agreement with the measured data, and the frequency characteristics of the transistors are well predicted.
关键词： parameter extraction,rational function fitting,transmission line,SiGe HBT,Device modeling,small-signal model
更新于2025-09-23 15:23:52
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Finite-Difference Time-Domain Modeling for Electromagnetic Wave Analysis of Human Voxel Model at Millimeter-Wave Frequencies
摘要： The finite-difference time-domain (FDTD) modeling of a human voxel model at millimeter-wave (mmWave) frequencies is presented. It is very important to develop the proper geometrical and electrical modeling of a human voxel model suitable for accurate electromagnetic (EM) analysis. Although there are many human phantom models available, their voxel resolution is too poor to use for the FDTD study of EM wave interaction with human tissues. In this paper, we develop a proper human voxel model suitable for mmWave FDTD analysis using the voxel resolution enhancement technique and the image smoothing technique. The former can improve the resolution of the human voxel model and the latter can alleviate staircasing boundaries of the human voxel model. Quadratic complex rational function is employed for the electrical modeling of human tissues in the frequency range of 6–100 GHz. Massage passing interface-based parallel processing is also applied to dramatically speed up FDTD calculations. Numerical examples are used to illustrate the validity of the mmWave FDTD simulator developed here for bio electromagnetics studies.
关键词： human tissue,electromagnetic wave,Doppler radar,dispersion model,bioelectromagnetics,Finite-difference time-domain (FDTD) method,parallel processing
更新于2025-09-23 15:23:52
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Non-blind image deblurring method by the total variation deep network
摘要： There are a lot of non-blind image deblurring methods, especially, with the total variation (TV) model-based method. However, how to choose the parameters adaptively for regularization is a major open problem. We proposed a very novel method which is based on TV deep network to learn the best parameters adaptively for regularization. We used deep learning and prior knowledge to set up a TV-based deep network and calculate parameters of regularization such as biases and weights. Therefore, we used the idea of a deep network to update these parameters automatically so that avoiding sophisticated calculations. Our experimental results by our proposed network are significantly better than several other methods, in respect of detail retention and anti-noise performance. At the same time, we can achieve the same effect with a minimum number of training sets, thus speeding up the calculation.
关键词： Total variation model,deep learning,Non-blind image deblurring
更新于2025-09-23 15:23:52
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Investigation of Reliability of Diversity Systems Through Stress-Strength Model Analysis
摘要： Paper concerns a problem of reliability indexes calculation of two channel homogeneous and diversity system. Using SSM it is easy to determine the probability of Common Cause Failures (CCF) and other parameters of investigated redundant systems. Here is used a complex approach with Multi-Factor Stress-Strength Model (MFSSM). The obtained analytical formulas are verificated via simulation.
关键词： diversity,common cause failures,stress-strength model,dependability
更新于2025-09-23 15:23:52
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[IEEE 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE) - Amsterdam (2018.8.27-2018.8.30)] 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE) - Terahertz Shielding Prediction of Id-Periodic N Anolayered Coatings by an Effective Homogeneous Model
摘要： An innovative effective-medium model of 1D-periodic multilayer coatings is developed by applying the transmission line method. Each period consisting of several layers with subwavelength thickness in the nanometer range is modelled as a homogeneous medium characterized by an effective complex conductivity and unit relative permeability. The resulting effective single layer (ESL), having the same total thickness of the multilayer laminate, is represented by a transfer matrix given by the product of the transmission matrices of the periods composing the structure. The effective homogeneous model is used to compute the shielding effectiveness of 1D-periodic photonic-band-gap transparent coatings made by alternating layers of silver and zinc oxide films in the frequency range up to 10 THz. The good accuracy of the results obtained using the ESL is demonstrated by comparison with the results computed by means of the rigorous multilayer formulation.
关键词： THz shielding effectiveness,1D-periodic multilayer coating,effective homogeneous model
更新于2025-09-23 15:23:52
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[IEEE 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Vladivostok, Russia (2018.10.3-2018.10.4)] 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Quality Control of Sodium High-Pressure Lamps by the Singular Decomposition Method
摘要： We created a mathematical model of a sodium high-pressure lamp. This model is used in production before sending lamps to the consumer. To develop the model, we used a mathematical model. An analytical method was used to describe the operation of a sodium lamp based on differential equations. We also used the singular value decomposition algorithm to find the coefficients of the ARMA model. Also, the transfer function of the ARMA model was obtained. Then we tested the models to control the quality of sodium lamps in production. The obtained results of the simulation coincide with the experimental results. A graphical dependence is obtained in the case when the standard deviation is 1. Using a series of tests based on the singular value decomposition method, we confirmed the adequacy of elaborated model by Kolmogorov-Smirnov criterion.
关键词： experimental research,mathematical model,sodium lamp
更新于2025-09-23 15:23:52
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[IEEE 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Vladivostok, Russia (2018.10.3-2018.10.4)] 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Modeling of the Magneto-Optical Channel of a Fiber-Optic Displacement Sensor
摘要： According to earlier studies conducted by the authors it was found that contactless fiber-optic sensors based on the magneto-optical Faraday effect (FOSF) in epitaxial films of iron garnet can be used for contactless monitoring of the status of control plate valves that regulate the flow of fire and explosion hazardous substances and operate over a wide temperature range. FOSF makes it possible to control the displacement and tilt angle of the valve regulating element (valve plate). However, at the moment there are no sufficiently accurate mathematical models for such FOSF. Studies have shown that the discrepancy between simulation results and experiments can reach 105%. The discrepancy between the results increases significantly when the FOSF is operated in a wide temperature range (from minus 196 to +80 °C). The low accuracy of the FOSF models does not make it possible to develop efficient means of compensating its intrinsic and complementary errors. The existing FOSF models are not sufficiently accurate, since they do not take into account: the distribution of the normal component of the magnetic field strength along the magneto-optical element (MOE) cross-section; the distribution of the optical radiation intensity along the MOE cross-section; optical absorption of the FOSF optical elements. According to the results of research carried out by the authors a set of mathematical models that takes into account the nonuniform distribution of the optical radiation intensity along the MOE cross-section, the nonuniform distribution of normal component of the magnetic field strength along the MOE cross-section, the optical absorption in FOSF optical elements and their temperature dependences was developed. This allowed us to significantly reduce the modelling error. The discrepancy between the results of mathematical modeling and experimental studies of FOSF prototypes does not exceed 7.2%.
关键词： control valve,contactless fiber optic sensor,mathematical model,fire and explosion safety,Faraday effect
更新于2025-09-23 15:23:52