- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Budapest (2018.7.1-2018.7.5)] 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Estimation of Frequency Dependent Dielectric Behavior of PP-SiO2 Nanocomposite Interphase at Different Temperatures
摘要： This work aims to emphasize the frequency dependent dielectric response of the interface region of a PP-SiO2 nanodielectric at different temperatures. The approach is that of an inverse problem technique, i.e. a numerical model was built and the frequency dependent dielectric properties of the interphase were estimated so that the modeling results in terms of effective permittivity (real part) and loss tangent be close to the dielectric spectroscopy results. The numerical results show that the proposed procedure provides a good estimation of the dielectric response of the interphase, which dominates the dielectric response of the whole nanodielectric.
关键词： dielectric spectroscopy,interface,nanodielectric,numerical modeling
更新于2025-09-23 15:19:57
-
Gaussian random number generator: Implemented in FPGA for quantum key distribution
摘要： Quantum key distribution is the process of using quantum communication to establish a shared key between two parties. It has been demonstrated the unconditional security and effective communication of quantum communication system can be guaranteed by an excellent Gaussian random number (GRN) generator with high speed and an extended random period. In this paper, we propose to construct the Gaussian random number generator by using field‐programmable gate array (FPGA), which is able to process large data in high speed. We also compare three algorithms of GRN generation: Box‐Muller algorithm, polarization decision algorithm, and central limit algorithm. We demonstrate that the polarization decision algorithm implemented in FPGA requires less computing resources and also produces a high‐quality GRN through the null hypothesis test.
关键词： field‐programmable gate array,numerical modeling,quantum key distribution,Gaussian random numbers
更新于2025-09-19 17:15:36
-
Numerical and experimental investigation of the formation mechanism and the distribution of the welding residual stress induced by the hybrid laser arc welding of AH36 steel in a butt joint configuration
摘要： Formation mechanism of the welding residual stress (WRS) is a key part of welding research. However, there is a lack of meaningful numerical models of the WRS. In this work, a thermal-metallurgical-mechanical (TMM) model was developed using SYSWELD to investigate the distribution and the formation mechanism of WRS during the hybrid laser arc welding of AH36 steel. A series of simulations were conducted to explore the effects of various factors on the WRS. The numerical results matched well with the experimental data. The computational accuracy was improved by considering the typical “wine glass” weld profile and the dilution rate during simulation. The evolution of the WRS is strongly affected by the interaction of phase transformation and strain hardening. The austenite-martensite transformation has a great potential to reduce the WRS whereas the austenite-bainite transformation produces high levels of WRS. The phase transformation temperature has a great influence on WRS.
关键词： Hybrid laser arc welding,Welding residual stress,Phase transformation,Numerical modeling
更新于2025-09-19 17:13:59
-
Optimization of the In0.3Ga0.7As-Layer Thickness in a Triple-Junction In0.3Ga0.7As/GaAs/In0.5Ga0.5P Solar Cell
摘要： The optimum absorbing-layer thickness in the bottom In0.3Ga0.7As subcell of a triple-junction In0.3Ga0.7As/GaAs/In0.5Ga0.5P solar cell is sought for using the Sentaurus TCAD software package as a factor of the minority charge-carrier lifetime in this layer. The lifetime is set in the range from 17 ps to 53 ns. The calculation results show that the optimum thickness varies from 0.9 to 7.5 μ m. In addition, the contribution of the bottom In0.3Ga0.7As subcell to the efficiency of this triple-junction solar cell is estimated at various lifetime values. Its value varies from 1 to 7%.
关键词： numerical modeling,Sentaurus TCAD,In0.3Ga0.7As,solar cell,optimum thickness
更新于2025-09-19 17:13:59
-
Electronic–Electromagnetic Multiphysics Modeling for Terahertz Plasmonics: A Review
摘要： In this article, we review numerical and analytical methods of electronic–electromagnetic multiphysics modeling for terahertz plasmonic applications. Approaches within semiclassical regime of electronic transport are considered, as these are appropriate for examining plasma-wave phenomenology in 2-D electron gas systems, commonly found in high-electron-mobility transistors (HEMTs) and graphene sheets. In modeling of such electronic–plasmonic devices, coupling of incident electromagnetic wave to the device or emission from the device needs to be modeled. Therefore, electronic–electromagnetic coupled multiphysics multiscale models are required. In such modeling problems, the domain consists of large regions where electrodynamic equations are to be solved. Therefore, overall time efficiency relies on the speed of solution of electrodynamic equations. Nevertheless, the electrodynamic solution’s speed is limited by the smallest grid sizes, which are a function of electronic transport equations. To address these issues, unconditionally stable finite-difference time-domain (FDTD) and iterative alternating directional implicit (ADI)-FDTD methods, coupled with hydrodynamic equations, are reviewed. Advantages and compromises between FDTD, ADI-FDTD, and iterative ADI-FDTD-based global modeling are discussed and conclusions are summarized.
关键词： electronic,numerical modeling,electron transport,terahertz (THz),FDTD,multiphysics,plasmonic,Alternating directional implicit finite-difference time-domain (ADI-FDTD),multiscale modeling,hydrodynamic (HD),plasma wave,electromagnetic
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE 5th International forum on Research and Technology for Society and Industry (RTSI) - Florence, Italy (2019.9.9-2019.9.12)] 2019 IEEE 5th International forum on Research and Technology for Society and Industry (RTSI) - Numerical Dynamic Modeling and Analysis of DC-DC Converters for Photovoltaic Applications
摘要： The analytic study of DC-DC converters is well suited for linear sources and loads. However, the study of the converter behavior in presence of non-linear sources, such as a photovoltaic devices, or loads, such as energy storage systems, requires either linearization techniques or numerical simulations. In this study, the behavior of a DC-DC conversion stage is analyzed through a state-space numerical approach, using as excitation the equivalent five-parameters circuit model used to represent a photovoltaic device. The whole simulation is carried out for variable environmental conditions (device irradiance and temperature) to assess the capabilities of the numerical model proposed to withstand quick variations of the excitation without exhibiting instabilities.
关键词： Photovoltaics,DCDC,Numerical Modeling
更新于2025-09-16 10:30:52
-
Numerical Modeling of Plasma Silicon Discharge for Photovoltaic Application
摘要： In this work, we perform a numerical modeling of silicon thin film deposition for a photovoltaic application in a capacitive coupled plasma reactor (CCP) using RF excitation. Plasma equations are solved by finite element numerical method. The deposition is done by plasma of SiH4/Ar/H2 in low pressure and low temperature. The results provide the fundamental features of plasma discharge such as density, temperature and electrical potential. It is shown that the gas mixture used covers a large energy range, which entails a high deposition rate. Furthermore, the use of CCP reactor yields a uniform deposition without surface deterioration.
关键词： Numerical modeling,RF Plasma,CCP reactor,SiH4/Ar/H2,Finite Element Method
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Boston, MA, USA (2019.5.29-2019.5.31)] 2019 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Parallel Modeling Fully Coupled Multiphysics Process in Resistive Random Access Memory Array
摘要： A high-performance numerical is proposed for fully coupled electrothermal simulation of electrothermal effects in resistive switching random access memory (RRAM) arrays. To enhance its capability for fast solving large scale problem, a J parallel adaptive unstructured mesh infrastructure and domain decomposition method (DDM) based double-level parallel scheme is employed to implement a parallel simulator. The performance of the developed simulator is validated by comparing with that of COMSOL Multiphysics. Further, the influence of conductive filament (CF) shape in the RRAM arrays on their electrothermal characteristics are investigated and analyzed.
关键词： Electrothermal model,numerical modeling,resistive-switching random access memory (RRAM),thermal crosstalk,parallel simulator
更新于2025-09-16 10:30:52
-
Optimization of production process of Mg tubes produced with laser dieless drawing method and related microstructural analysis
摘要： This contribution deals with a laser dieless drawing method in which tubes (AZ31 magnesium alloy) with small dimensions are produced from previously extruded tubes with a larger diameter. The process involves local laser heating of a tube with concurrent drawing and rotation of a sample. The control parameters need to be optimized in order to get a good quality tube with low damage and regular diameter. Here, a previously developed finite element (FE) model is used for the numerical optimization. The optimization itself is multi-objective, maximizing the uniformity of the resulting tube but concurrently, minimizing its critical deformation. Since one run of the FE code lasts for several days, an approximation by a Radial Basis Function meta-model (surrogate) is used. Results reveal that there is only a very limited number of combinations of parameters leading to a uniformly shaped tubes. Finally, tubes produced with optimized parameters are analyzed from the microstructural point of view.
关键词： Laser dieless drawing process,Microstructural analysis,Optimization,Numerical modeling,Magnesium alloys
更新于2025-09-12 10:27:22
-
Improving the R&D process efficiency of the selective laser sintering industry through numerical thermal modeling
摘要： The selective laser melting (SLS) industry is a relatively novel industry within the broad spectrum of available additive manufacturing (AM) technologies. As with most developing industries, the primary aim is to develop better quality components at reduced costs, often with a disregard towards efficiency. Resource efficiency is a key component of waste management and ties directly to sustainable manufacturing. In the SLS industry, large quantities of raw material are wasted during the machine calibration stage. Each time a new material is developed for SLS manufacturing a specific set of processing parameters need to be developed in order to ensure that high density, high strength components are produced. This paper investigates the possibility of replacing the current inefficient research and development (R&D) methods with numerical modeling. The fusion process can be simulated in a numerical thermal model using a combination of temperature dependent material properties and heat transfer principles.
关键词： tungsten carbide,powder bed fusion,numerical modeling,Additive manufacturing,process chain
更新于2025-09-12 10:27:22