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Design and development of radio frequency output window for circular electron–positron collider klystron

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Chinese Physics B 2018年第11期27卷 620-625页

作者： Zhijun Lu Shigeki Fukuda Zusheng Zhou Shilun Pei Shengchang wang Ouzheng Xiao UnNisa Zaib Bowen Bai Guoxi Pei Dong Dong Ningchuang Zhou shaozhe wang Yunlong Chi Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China High Energy Accelerator Research Organization KEK Oho Ibaraki 305-0801 Japan GLVAC Industrial Technology Research Institute of High Power Devices Kunshan 215300 China

This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water *** design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.

关键词： klystron coaxial radio frequency window thermal stress multipacting

Xi-Obama Meet Sets Tone for Future of Sino-U.S. Relations

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Magnetic resonance imaging characteristics of patients with neuropsychiatric systemic lupus erythematosus

今日中国·英文版 2013年第7期 18-19页

作者： wang shaozhe LIAO QIN Jiefang Daily

关键词：加利福尼亚州美国总统习近平领导人办公室多媒体中国

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Chinese Medical Journal 2024年第3期137卷 373-375页

作者： Yanli Huang Shuoqi Zhang shaozhe Cai Bingxia Ming Rongfen Gao Ziwei Hu Lingli Dong Department of Rheumatology and Immunology Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubei 430030China Department of Rheumatology and Immunology Yueyang Central HospitalYueyangHunan 414000China Department of Radiology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430030China

To the Editor:Neuropsychiatric systemic lupus erythematosus(NPSLE)is a group of serious complications of systemic lupus erythematosus(SLE)with poor prognosis and high mortality.^([1])Therefore,identifying risk factors for NPSLE is particularly crucial for the improvement of the outcomes of *** resonance imaging(MRI)is currently the imaging test of choice for diagnosing patients with ***,almost half of the patients with NPSLE show no abnormalities on conventional MRI.^([2])Therefore,the correlation between neuropsychiatric symptoms,which refer to multiple neuropsychiatric manifestations directly related to SLE,and MRI findings should be urgently *** this study,we investigated the clinical features,outcomes,and prognostic factors of NPSLE and analyzed the correlation of neuropsychiatric symptoms with MRI features.

关键词： psychiatric patients erythematosus

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用于细胞活性研究的高重频脉冲磁场装置

电工技术学报 2024年第13期39卷 3907-3916页

作者：樊俊显张绍哲李可欣相文佩韩小涛华中科技大学国家脉冲强磁场科学中心武汉430074 强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院) 武汉430074 华中科技大学同济医学院生殖健康研究所武汉430074

一定时间的脉冲磁场序列可刺激某些类型的细胞和组织产生有益的生物效应。由于磁体本质上是一个大感性负载,难以同时实现磁体电流的高di/dt和高精度调节。为此,该文提出一种两级联合调控拓扑,前级电路为同步降压电路,用于实现di/dt随磁... 详细信息

一定时间的脉冲磁场序列可刺激某些类型的细胞和组织产生有益的生物效应。由于磁体本质上是一个大感性负载,难以同时实现磁体电流的高di/dt和高精度调节。为此,该文提出一种两级联合调控拓扑,前级电路为同步降压电路,用于实现di/dt随磁场期望值同步调节,后级电路是桥式电路,用于实现脉冲磁场波形周期、振幅、稳定度、刺激间隔等参数的控制,为了实现电流从快速上升到稳定值的平滑过渡,引入一种由滞环控制器和PI控制器组成的混合型控制器。在此基础上,研制了频率范围为1 Hz~5 kHz、脉冲边沿小于50μs、可调精度为0.1 mT、峰值强度高达10 mT的便携式高频脉冲磁场发生装置样机,并应用于脉冲磁场对高龄小鼠的体外成熟卵母细胞受精和胚胎发育能力影响的研究。在脉冲磁场作用下囊胚形成率从15.15%提高至52.94%,表明脉冲磁场显著促进了高龄小鼠体外成熟卵母细胞的发育能力。

关键词：重频脉冲磁场细胞活性磁场发生装置混合型控制器

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市政道路的雨污水管网施工关键技术分析

建设科技 2024年第12期 33-35页

作者：刘绍喆中铁二十五局集团第一工程有限公司广州510000

随着城市化进程的快速推进,市政道路的雨污水管网建设已成为城市基础设施建设的核心环节。基于此,本文分析市政道路雨污水管网施工中的设计、选材、施工技术、质量控制等方面关键技术,并提出施工过程中的安全保障、环境保护、技术支持... 详细信息

随着城市化进程的快速推进,市政道路的雨污水管网建设已成为城市基础设施建设的核心环节。基于此,本文分析市政道路雨污水管网施工中的设计、选材、施工技术、质量控制等方面关键技术,并提出施工过程中的安全保障、环境保护、技术支持等保障措施,旨在为市政道路的雨污水管网施工提供全面、深入的理论支持、实践指导,以提升施工质量和效率。

关键词：市政道路雨污水管网施工技术材料选择质量控制

Machine-learning-based models assist the prediction of pulmonary embolism in autoimmune diseases: A retrospective, multicenter study

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中华医学杂志(英文版) 2024年第15期137卷 1811-1822页

作者： Hu Ziwei Hu Yangyang Zhang Shuoqi Dong Li Chen Xiaoqi Yang Huiqin Su Linchong Hou Xiaoqiang Huang Xia Shen Xiaolan Ye Cong Tu Wei Chen Yu Chen Yuxue Cai shaozhe Zhong Jixin Dong Lingli Department of Rheumatology and Immunology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan Hubei China Department of Radiology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan Hubei China Department of Rheumatology and Immunology Jingzhou Central Hospital Yangtze University Jinzhou Hubei China Department of Rheumatology and Immunology Zhongnan Hospital Wuhan University Wuhan Hubei China Department of Rheumatology Wuhan No.Hospital Wuhan Hubei China Department of Rheumatology Minda Hospital of Hubei Minzu University Enshi Hubei China Department of Rheumatology and Immunology The First College of Clinical Medical Science China Three Gorges University Yichang Hubei China

Background: Pulmonary embolism (PE) is a severe and acute cardiovascular syndrome with high mortality among patients with autoimmune inflammatory rheumatic diseases (AIIRDs). Accurate prediction and timely intervention play a pivotal role in enhancing survival rates. However, there is a notable scarcity of practical early prediction and risk assessment systems of PE in patients with ***: In the training cohort, 60 AIIRD with PE cases and 180 age-, gender-, and disease-matched AIIRD non-PE cases were identified from 7254 AIIRD cases in Tongji Hospital from 2014 to 2022. Univariable logistic regression (LR) and least absolute shrinkage and selection operator (LASSO) were used to select the clinical features for further training with machine learning (ML) methods, including random forest (RF), support vector machines (SVM), neural network (NN), logistic regression (LR), gradient boosted decision tree (GBDT), classification and regression trees (CART), and C5.0 models. The performances of these models were subsequently validated using a multicenter validation ***: In the training cohort, 24 and 13 clinical features were selected by univariable LR and LASSO strategies, respectively. The five ML models (RF, SVM, NN, LR, and GBDT) showed promising performances, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.962-1.000 in the training cohort and 0.969-0.999 in the validation cohort. CART and C5.0 models achieved AUCs of 0.850 and 0.932, respectively, in the training cohort. Using D-dimer as a pre-screening index, the refined C5.0 model achieved an AUC exceeding 0.948 in the training cohort and an AUC above 0.925 in the validation cohort. These results markedly outperformed the use of D-dimer levels ***: ML-based models are proven to be precise for predicting the onset of PE in patients with AIIRD exhibiting clinical suspicion of *** Registration: ***: ChiCTR2200059599.

关键词： Autoimmune inflammatory rheumatic diseases Pulmonary embolism Predictive model Machine learning

清末天津青年会外籍干事的日常生活(1895—1911)

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浙江师范大学学报（社会科学版） 2024年第4期49卷 32-46页

作者：庞少哲浙江师范大学马克思主义学院浙江金华321004

清末,外籍干事作为天津青年会的管理者,身兼外籍教师、传教士、学者等社会角色,同时,作为“常人”,具有在日常生活中衣食住行等方面的需求。在天津的外籍干事居市井、食中餐、乘人力车、说汉语,面向中国民众开展各类世俗性活动,皆是主... 详细信息

清末,外籍干事作为天津青年会的管理者,身兼外籍教师、传教士、学者等社会角色,同时,作为“常人”,具有在日常生活中衣食住行等方面的需求。在天津的外籍干事居市井、食中餐、乘人力车、说汉语,面向中国民众开展各类世俗性活动,皆是主动适应地方社会、本土化的外在表现形式,背后有宗教精神作支撑。因清末基督教在华处境的边缘性,外籍干事的布道策略更趋间接性和隐蔽性。其日常生活既是西方来华群体在华活动不可或缺的一部分,更是管窥中西文化调适与应对的缩影。

关键词：天津中华基督教青年会外籍干事日常生活本土调适中国化

低温热致相分离法制备PVDF-CTFE多孔膜的研究

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膜科学与技术 2024年第2期44卷 55-63页

作者：林帅吕晓龙张绍哲谷杰任凯天津工业大学省部共建分离膜与膜过程国家重点实验室材料科学与工程学院生物化工研究所天津300387 膜材料与膜应用国家重点实验室天津膜天膜科技股份有限公司天津300457

利用低温热致相分离法制备了PVDF-CTFE多孔膜,重点考察了甘油含量和凝固浴温度对成膜机理和性能的影响.结果表明,甘油有促进热致相分离(TIPS)和非溶剂致相分离(NIPS)的双重作用.甘油含量的提高,一方面作为非溶剂使铸膜液浊点温度与凝固... 详细信息

利用低温热致相分离法制备了PVDF-CTFE多孔膜,重点考察了甘油含量和凝固浴温度对成膜机理和性能的影响.结果表明,甘油有促进热致相分离(TIPS)和非溶剂致相分离(NIPS)的双重作用.甘油含量的提高,一方面作为非溶剂使铸膜液浊点温度与凝固浴温度的温差变大,加强了TIPS效应,使膜结构呈TIPS效应为主的双连续结构,避免了NIPS效应所致典型的指状孔结构;另一方面作为NIPS的致孔剂,会加强NIPS效应,促使发生双扩散,生成更多孔结构,二者竞争共同作用.最终甘油含量的提高使TIPS效应占主导,NIPS所致的皮层结构变薄,膜断面结构从致密堆积状向多孔蜂窝状结构转变,提高了膜的通透性.当甘油添加量为7.5%(质量分数)时,PVDF-CTFE中空纤维多孔膜综合性能最佳,拉伸断裂强度达2.6 MPa,纯水通量达860 L/(m^(2)·h·MPa).凝固浴温度的提高,减少了铸膜液浊点温度与凝固浴的温差,减弱了TIPS效应,加强了NIPS效应的传质过程,使膜结构从蜂窝状结构向指状孔结构转变,皮层厚度增加,导致膜孔隙率和纯水通量提高,力学性能下降.当凝固浴温度为80℃时,PVDF-CTFE平板多孔膜的纯水通量为1510 L/(m^(2)·h·MPa),拉伸断裂强度为2.1 MPa.

关键词：聚偏氟乙烯-三氟氯乙烯低温热致相分离成膜机理多孔膜凝固浴温度

Realisation of the reconfigurable pulsed high magnetic field facility and its scientific application at Wuhan National Pulsed High Magnetic Field Centre

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High Voltage 2023年第5期8卷 898-906页

作者： Jianfeng Xie shaozhe Zhang Jiangtao Shi Junfeng wang Liang Li Xiaotao Han Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhanChina State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhanChina

To generate arbitrary shape magnetic field waveforms for advanced scientific research,a reconfigurable pulsed high magnetic field facility(PHMFF)was developed at Wuhan National Pulsed High Magnetic Field Centre(WHMFC).First,the basic elements of PHMFF are introduced,and a ternary physical model composed of energy storage unit,magnet,transmission circuits and other auxiliary units is summarised to describe various magnetic field ***,in order to realise the reconfiguration of magnetic field systems based on detailed elements,the control system with the ability of dynamic construction and control sequence reconfiguration is *** this basis,the PHMFF has been realised and various magnetic field systems are constructed to produce arbitrary shape magnetic field waveforms,such as half‐sine,ultra‐high,flat‐top and repetitive field pulses,which not only enhances the capability and efficiency of PHMFF,but also makes more scientific research possible in pulsed magnetic *** far,a peak magnetic field of 94.8 T,a flat‐top magnetic field of 64 T/10 ms and a repetitive magnetic field waveform of 20 T/60 Hz have been achieved,and some experiments and studies on the physical properties of materials have been carried out at WHMFC.

关键词： magnetic field pulsed