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Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： Qiang Liu Xiang Li Shen Du Ming Gao Yanbin Yin Jiongming Zhang state key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity

Model and Simulation of a New Ultra-Narrow Trigger Frequency Alterable Pulse Generator

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Journal of Shanghai Jiaotong university(Science) 2011年第6期16卷 687-690页

作者：杨运峰曹振新叶展窦文斌苏宏艳 state key laboratory of millimeter waves Southeast University National key laboratory of millimeter wave System

Two new kinds of ultra-narrow trigger frequency alterable picosecond pulse generator are *** can produce positive pulses and the other can produce negative *** two pulse generators are subdivided into three parts:signal driving circuit,differentiator network and pulse shaping *** pulse shaping circuit is made of step recovery diode(SRD) and short-circuit microstrip line.A positive pulse with width of 54 ps(50%-50%),rising time of 30 ps(10%-90%) and falling time of 32 ps(90%-10%),and a negative pulse with width of 54 ps(50%-50%),rising time of 30 ps(90%-10%) and falling time of 30 ps(10%-90%) are achieved in *** of the components are ready-made and *** can be applied in ultra-wideband(UWB) communication system,such as transmitters and receivers.

关键词： pulse generator ultra-narrow step recovery diode(SRD) pulse shaping circuit

Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng Li Meifeng Cai Shengjun Miao Yuan Li Yu Wang key laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China state key laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China key laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China state key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

Design and implementation of 83-nm low noise InP-based InAlAs/InGaAs PHEMTs

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Journal of Semiconductors 2015年第8期36卷 83-87页

作者：王志明赵卓彬胡志富黄辉崔玉兴孙希国默江辉李亮付兴昌吕昕 Beijing key laboratory of millimeter wave and terahertz Technology Beijing Institute of Technology Hebei Semiconductor Research Institute National Institute of Metrology

83-nm T-shaped gate InP-based In0.52Al0.48As/In0.65Ga0.35As pseudomorphic high electron mobility transistors （PHEMTs） with excellent DC and RF performance as well as low noise characteristics are reported, including a maximum saturation current density/ass of 894 mA/mm, a maximum extrinsic transconductance gm, max of 1640 mS/mm, an extrapolated cutoff frequency ft of 247 GHz and a maximum oscillation frequency fmax of 392 GHz which were based on the measured S-parameters from 1 to 110 GHz. The minimum noise figure （NFmin） measured by the cold-source method is 1 dB at 30 GHz associated with a gain of 14.5 dB at Vds of 0.8 V and Ids of 17 mA. These results were obtained by the combination of increased InAs mole fraction in the channel, gate size scaling, parasitic reduction and the quantization channel. These excellent results make it one of the most suitable devices for millimeter wave （MMW） low noise applications.

关键词： InP PHEMT millimeter wave low noise on-wafer measurement

Comparison of on-wafer calibrations for THz In P-based PHEMTs applications

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Journal of Semiconductors 2015年第6期36卷 64-67页

作者：王志明黄辉胡志富赵卓彬王旭东罗晓斌刘军杨宋源吕昕 Beijing key laboratory of millimeter wave and terahertz Technology Beijing Institute of Technology National Institute of Metrology Hebei Semiconductor Research Institute

A quantitative comparison of multiline TRL （thru-reflect-line） and LRM （line-reflect-match） on-wafer calibrations for scattering parameters （S-parameters） measurement of InP-based PHEMTs is presented. The com- parison is undertaken for the first time and covers a frequency range from 70 kHz to 110 GHz. It is demonstrated that the accuracy of multiline TRL and LRM calibration is in good agreement. Both methods outperform the conven- tional SOLT calibration in the full frequency band up to 110 GHz. Then the excellent RF performance is obtained by extrapolation on the basis of inflection point, including a maximum current gain cut-off frequency ft of 247 GHz and a maximum oscillation frequency fmax of 392 GHz. The small-signal model based on LRM calibration is es- tablished as well. The S-parameters of the model are consistent with the measured from 1 to 110 GHz.

关键词： on-wafer calibration scattering parameters PHEMTs small-signal model

Display technique based on surface plasmon resonant effect

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Chinese Science Bulletin 2008年第15期53卷 2257-2264页

作者： CAO ZhenXin WU LeNan state millimeter wave key laboratory Southeast University Nanjing 210096 China

In a surface plasmon resonant (SPR) configuration, real part in refraction coefficient of modulation layer material is monotonic with resonant wave length, while imaginary part is monotonic with resonant magnitude. Based on the fact above, a new type of display is proposed and designed. Firstly, a display pixel with either controllable color or controllable brightness is discussed, and then a display pixel with both controllable color and brightness is proposed in detail. At last, an SPR display with 8×8 pixels is developed and simulated. The results show that color and brightness of each display pixel in an SPR display can be tuned directly, with no need of synthesizing three basic colors, traditionally. Moreover, the display has many merits, such as high color resolution, high contrast, high brightness, fast re-sponse, etc. Yet practical usage of SPR display demands deeper study on properties of modulation layer material and fabrication techniques.

关键词： SPR效应自然色表面等离子共振仪分层材料

Large Signal Statistical Model Oriented Parameter Extraction Method for GaN High Electron Mobility Transistors

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Chinese Journal of Electronics 2017年第6期26卷 1319-1324页

作者： YU Xuming XU Yuehang WEN Zhang CHEN Zhikai HONG Wei state key laboratory of millimeter wave Southeast Univeristy School of Electronic Engineering University of Electronic Science and Technology of China

Efficient parameter extraction method is essential to establish large signal statistical model. This paper presents an automatic parameter extraction method of I-V model for Gallium nitride(GaN) High electron mobility transistors(HEMTs) large signal statistical model. To accurate modeling the statistical characterization, all of 53 parameters in an I-V model are considered. In order to realize automatic parameter extraction, the model parameters are divided into blocks according to their physical meaning to reduce the complexity of the I-V model. Different parameter blocks are extracted separately by fitting the pulsed I-V transfer characteristic curves of the device at different quiescent bias points. A large signal statistical model for 0.25μm GaN HEMTs process has been established by using the proposed method after measuring 34 GaN HEMTs from 10 batches. The results show that the large-signal performances(Output power and Power added efficiency) can be reproduced with high accuracy by the proposed statistical model.

关键词： Statistical model Parameter extraction GaN HEMTs Large signal model

Design of InAlAs/InGaAs PHEMTs and small-signal modeling from 0.5 to 110 GHz

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Journal of Semiconductors 2015年第2期36卷 72-76页

作者：王志明吕昕罗晓斌崔玉兴孙希国默江辉付兴昌李亮何大伟 Beijing key laboratory of millimeter wave and terahertz Technology Beijing Institute of Technology National key laboratory of Application Specific Integrated Circuit (ASIC) Hebei Semiconductor Research Institute

90-nm T-shaped gate InP-based In_（0.52）Al_（0.48）As/In_（0.6）Ga_（0.4）As pseudomorphic high electron mobility transistors were designed and fabricated with a gate-width of 2×30 μm,a source-drain space of 2.5 μm,and a source-gate space of 0.75 μ***,RF and small-signal model characterizations were *** maximum saturation current density was measured to be 755 mA/mm biased at V_（gs）=0.6 V and V_（ds）=1.5 *** maximum extrinsic transconductance was measured to be 1006 mS/mm biased at V_（ds）=—0.1V and V_（ds）=1.5 *** extrapolated current gain cutoff frequency and maximum oscillation frequency based on S-parameters measured from 0.5 to 110 GHz were 180 and 264 GHz,*** inflection point（the stability factor k=1）where the slope from-10 dB/decade（MSG） to-20 dB/decade（MAG） was measured to be 83 *** smallsignal model of this device was also established,and the S-parameters of the model are consistent with those measured from 0.5-110 GHz.

关键词： InP PHEMTs InAlAs/InGaAs MMICs small-signal modeling