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Scalable Multi-harmonic Large-Signal Model for AlGaN/GaN HEMTs Including a Geometry-Dependent Thermal Resistance

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Chinese Journal of Electronics 2017年第5期26卷 952-959页

作者： WANG Changsi XU Yuehang WEN Zhang chen zhikai XU Ruimin School of Electronic Engineering University of Electronic Science and Technology of China

A scalable large-signal model of AlGa N/Ga N High electron mobility transistors(HEMTs)suitable for multi-harmonic characterizations is *** model is fulfilled utilizing an improved drain-source current(Ids) formulation with a geometry-dependent thermal resistance(Rth) and charge-trapping *** Idsmodel is capable of accurately modeling the highorder transconductance(gm),which is significant for the prediction of multi-harmonic *** thermal resistance is identified by the electro-thermal Finite element method(FEM) simulations,which are physically and easily scalable with the finger numbers,unit gate width and power dissipations of the *** predictions of the quiescent currents,S-parameters up to 40 GHz,and large-signal harmonic performance for the devices with different gate peripheries have been achieved by the proposed model.

关键词： GaN HEMTs Large-signal model Scalable model Thermal resistance

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环形桥塔侧倾稳定临界荷载的解析计算方法

广东公路交通 2024年第3期50卷 45-49,73页

作者：李俊陈彪刘顺发陈志凯广东大道检测技术有限公司广东中山528400 华南理工大学广东广州510641

本文以自锚式悬索桥的环形桥塔为研究对象,基于曲线构件的空间弯扭变形的基本方程,获得环形塔侧倾时的弯扭变形能和荷载作用产生的外力势能,采用能量法推导出了环形桥塔的侧倾失稳临界荷载的解析解,提出了环形桥塔侧倾失稳临界荷载的计... 详细信息

本文以自锚式悬索桥的环形桥塔为研究对象,基于曲线构件的空间弯扭变形的基本方程,获得环形塔侧倾时的弯扭变形能和荷载作用产生的外力势能,采用能量法推导出了环形桥塔的侧倾失稳临界荷载的解析解,提出了环形桥塔侧倾失稳临界荷载的计算方法。通过实例,将本文的理论计算值与有限元计算结果比较,验证了本文给出的计算方法的正确性。本文还分析了环形桥塔的半径、圆心角和截面刚度等参数的变化对环形桥塔侧倾稳定性的影响,研究结果表明环形桥塔的侧向抗弯对其侧倾稳定性贡献较大,而环形桥塔的半径与圆心角的选取对其侧倾稳定性的影响应获得重视。

关键词：环形桥塔侧倾稳定临界荷载能量法

Electrocatalytic oxidation of 5-hydroxymethylfurfural for sustainable 2,5-furandicarboxylic acid production-From mechanism to catalysts design

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SusMat 2023年第1期3卷 21-43页

作者： Xiaoli Jiang Wei Li Yanxia Liu Lin Zhao zhikai chen Lan Zhang Yagang Zhang Sining Yun School of Materials and Energy University of Electronic Science and Technology of ChinaChengduChina State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengduChina Univ Lyon CNRSINSA-LyonUniversite Claude Bernard Lyon 1VilleurbanneFrance School of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’anChina

Catalytic conversion of biomass-based platform chemicals is one of the significant approaches to utilize renewable biomass resources.2,5-Furandicarboxylic acid(FDCA),obtained by an electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF),has attracted extensive attention due to the potential of replacing terephthalic acid to synthesize high-performance polymeric materials for *** the present work,the pHdependent reaction pathways and factors influencing the degree of functional group oxidation are first *** the reaction mechanism of HMF oxidation is further elucidated using the representative *** addition,the emerging catalyst design strategies(defects,interface engineering)used in HMF oxidation are generalized,and structure-activity relationships between the abovementioned strategies and catalysts performance are ***,cathode pairing reactions,such as hydrogen evolution reaction,CO_(2) reduction reaction(CO_(2)RR),oxygen reduction reaction,and thermodynamically favorable organic reactions to lower the cell voltage of the electrolysis system,are ***,the challenges and prospects of the electrochemical oxidation of HMF for FDCA are presented,focusing on deeply investigated reaction mechanism,coupling reaction,reactor design,and downstream product separation/purification.

关键词： 5-hydroxymethylfurfural catalysts design strategies electrocatalytic oxidation pairing reactions reaction mechanism

Microstructure and wear resistance of Fe-based and Co-based coating of AISI H13

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China Welding 2019年第3期28卷 54-60页

作者： Yun Xiao Wang Jing Zhu Qinghai chen zhikai He Bing Jiangsu XCMG Construction Machinery Research Institute Co.Ltd Xuzhou 221004China State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery Xuzhou 221004China

Fe-based and Co-based cladding layers were prepared on the surface of AISI H13 hot die steel by laser cladding *** microstructure,hardness and abrasion resistance of the two cladding layers were studied by means of optical microscope,scanning electron microscope,rockwell hardness tester,and high temperature friction and wear ***,the red hardness of the cladding layers was measured,after holding the layers at 600℃ for 1 hour by muffle furnace and repeated 4 *** rockwell hardness values of the substrate,the Fe-based and the Co-based alloy coating measured were HRC 47,HRC 52 and HRC 48,*** red hardness values of the substrate and the Fe-based cladding layer were decreased,while that of the Co-based cladding layer was *** Co-based cladding layer has the minimal wear loss weight and friction coefficient among *** wear mechanisms of the substrate,the Fe-based layer and the Cobased layer attribute mainly to abrasive wear,adhesion wear,and both of them,respectively.

关键词： laser cladding AISI H13 Co-based coating red hardness high temperature wear

ThyroidNet:A Deep Learning Network for Localization and Classification of Thyroid Nodules

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 361-382页

作者： Lu chen Huaqiang chen zhikai Pan Sheng Xu Guangsheng Lai Shuwen chen Shuihua Wang Xiaodong Gu Yudong Zhang Ultrasonic Department Zhongda Hospital Affiliated to Southeast UniversityNanjing210009China School of Physics and Information Engineering Jiangsu Second Normal UniversityNanjing211200China School of Computing and Mathematical Sciences University of LeicesterLeicesterLE17RHUK Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia State Key Laboratory of MillimeterWaves Southeast UniversityNanjing210096China Jiangsu Province Engineering Research Center of Basic Education Big Data Application Jiangsu Second Normal UniversityNanjing211200China School of Software Engineering Quanzhou Normal UniversityQuanzhou362000China Department of Biological Sciences Xi’an Jiaotong-Liverpool UniversitySuzhou215123China

Aim:This study aims to establish an artificial intelligence model,ThyroidNet,to diagnose thyroid nodules using deep learning techniques ***:A novel method,ThyroidNet,is introduced and evaluated based on deep learning for the localization and classification of thyroid ***,we propose the multitask TransUnet,which combines the TransUnet encoder and decoder with multitask ***,we propose the DualLoss function,tailored to the thyroid nodule localization and classification *** balances the learning of the localization and classification tasks to help improve the model’s generalization ***,we introduce strategies for augmenting the ***,we submit a novel deep learning model,ThyroidNet,to accurately detect thyroid ***:ThyroidNet was evaluated on private datasets and was comparable to other existing methods,including U-Net and *** results show that ThyroidNet outperformed these methods in localizing and classifying thyroid *** achieved improved accuracy of 3.9%and 1.5%,***:ThyroidNet significantly improves the clinical diagnosis of thyroid nodules and supports medical image analysis *** research directions include optimization of the model structure,expansion of the dataset size,reduction of computational complexity and memory requirements,and exploration of additional applications of ThyroidNet in medical image analysis.

关键词： ThyroidNet deep learning TransUnet multitask learning medical image analysis

Violet/blue photoluminescence from CeO_2 thin film

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Chinese Science Bulletin 2003年第2期48卷 1198-1200页

作者： CHAI Chunlin, YANG Shaoyan, LIU zhikai, LIAO Meiyong & chen Nuofu Key Laboratory of Semiconductor Material Science, Institute of Semi-conductors, Chinese Academy of Sciences, Beijing 100083, China Key Laboratory of Semiconductor Material Science Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

CeO2 thin film was fabricated by dual ion beam epitaxial technique. The violet/blue PL at room temperature and lower temperature was observed from the CeO2 thinfilm. After the analysis of crystal structure and valence in the compound was carried out by the XRD and XPS technique, it was inferred that the origin of CeO2 PL was due to theelectrons transition from Ce4f band to O2p band and thedefect level to O2p band. And these defects levels were lo-cated in the range of 1 eV around Ce4f band.

关键词： cerium dioxide thin film PL violet/blue.

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H13钢的铁基和钴基熔覆层组织与耐磨性

焊接学报 2018年第12期39卷 105-109,133页

作者：员霄王井朱青海陈志凯何冰江苏徐工工程机械研究院有限公司徐州221004 高端工程机械智能制造国家重点实验室徐州221004

采用激光熔覆技术在AISI H13热作模具钢表面分别制备了铁基熔覆层、钴基熔覆层.借助金相显微镜、扫描电镜、洛氏硬度计和高温摩擦磨损试验机,对比分析了两种熔覆层的组织形貌、硬度和耐磨性.采用马弗炉进行加热600℃,保温1 h,反复4次,... 详细信息

采用激光熔覆技术在AISI H13热作模具钢表面分别制备了铁基熔覆层、钴基熔覆层.借助金相显微镜、扫描电镜、洛氏硬度计和高温摩擦磨损试验机,对比分析了两种熔覆层的组织形貌、硬度和耐磨性.采用马弗炉进行加热600℃,保温1 h,反复4次,并测得红硬性硬度.结果表明,基材、铁基、钴基熔覆层硬度分别为HRC 47,HRC 52,HRC 48.基材和铁基熔覆层的红硬性硬度有所下降,而钴基熔覆层的红硬性硬度提升.钴基熔覆层磨损失重量和摩擦系数皆最小.基材、铁基熔覆层、钴基熔覆层的磨损机理分别是以磨粒磨损、粘着磨损以及粘着磨损和磨粒磨损为主.

关键词：激光熔覆 H13热作模具钢钴基熔覆层红硬性硬度高温摩擦磨损

基于文本语义和社交行为信息融合的讽刺检测方法

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网络与信息安全学报 2023年第4期9卷 134-143页

作者：付朝阳陈致凯潘理上海交通大学网络安全技术研究院上海200240 信息安全综合管理技术研究上海市重点实验室上海200240 上海交通大学张江高等研究院上海200240

讽刺是一种复杂的隐式情感,讽刺检测是文本情感分析领域的重要研究问题,对于社交网络舆情分析有极强的现实意义。讽刺文本的表层语义和用户的真实情感往往相反,基于表层语义的文本情感检测通常会得到错误的分类结果。日常交流中的讽刺... 详细信息

讽刺是一种复杂的隐式情感,讽刺检测是文本情感分析领域的重要研究问题,对于社交网络舆情分析有极强的现实意义。讽刺文本的表层语义和用户的真实情感往往相反,基于表层语义的文本情感检测通常会得到错误的分类结果。日常交流中的讽刺往往借助语调、神态等非文本信息进行表达,因此单纯基于文本语义的讽刺检测方法无法利用非文本信息,极大地制约了检测效果。为了充分利用文本语义与用户社交行为信息,提升讽刺检测效果,提出了一种基于文本语义和社交行为信息融合的讽刺检测方法。该方法构造了包含用户、文本、情感词的异质信息网络,并设计了一种用于异质信息图表征向量计算的图神经网络模型。该模型使用双重注意力机制提取社交行为信息,通过情感子图挖掘文本深层语义,最终得到融合文本语义和社交行为信息的融合特征向量。融合特征向量可以用于训练分类器,进而完成社交网络文本讽刺检测。在推特真实数据集上的充分实验表明,所提方法的分类效果优于现有的讽刺文本检测方法。

关键词：讽刺检测图神经网络异质信息融合隐式情感分析

激光熔覆制备316L涂层组织及腐蚀行为研究

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激光与光电子学进展 2020年第3期57卷 140-146页

作者：刘朋陈志凯金全明朱青海徐州徐工液压件有限公司江苏徐州221004 江苏徐工工程机械研究院有限公司江苏徐州221004 高端工程机械智能制造国家重点实验室江苏徐州221004

为提升金属零件表面耐蚀性,采取激光熔覆技术在45#钢基体表面制备316L涂层。采用光学显微镜、能谱仪、扫描电镜、显微硬度仪等设备对涂层硬度、组织形貌、晶体类型等进行表征。结果显示,在一定加工参数下,涂层与基体呈良好的冶金结合,... 详细信息

为提升金属零件表面耐蚀性,采取激光熔覆技术在45#钢基体表面制备316L涂层。采用光学显微镜、能谱仪、扫描电镜、显微硬度仪等设备对涂层硬度、组织形貌、晶体类型等进行表征。结果显示,在一定加工参数下,涂层与基体呈良好的冶金结合,晶体类型主要为奥氏体组织,在晶间处存在少量的Cr23C6。316L涂层晶体尺寸随着能量密度的增加而增加,硬度则随之降低。当能量密度小于等于19J·mm^-2时,涂层易出现球化与毛化现象,当能量密度过高时,表面则出现涂层过烧,导致部分元素被烧损。通过分析腐蚀形貌可知:316L涂层的腐蚀失效形式主要为晶间腐蚀,同时表面存在少量的腐蚀坑;随着晶间腐蚀的加剧,45#钢基体开始出现腐蚀,表面形成大量的氧化层。

关键词：激光光学耐蚀性激光熔覆 316L涂层能量密度晶间腐蚀