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Optimal Allocation of Fault Current Limiter in MMC-HVDC Grid Based on Transient Energy Flow

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1786-1796页

作者： Meiqin Mao Hui Lu Dejian Cheng zhuang he Research Centre for Photovoltaic System Engineering.MOE Hefei University of TechnologyHefei 230009China

Economical and reliable protection of DC-side shortcircuit faults has become a key technology for promoting the development of module multilevel converters based on the high voltage direct current grid(MMC-HVDC-Grid).The fault current limiter(FCL)can effectively suppress the rapid development of the fault current and reduce the current breaking capacity of the circuit *** this paper,a method based on transient energy flow(TEF)analysis is proposed to optimize the allocation of a resistive and inductive FCL in the *** the proposed method,the electromagnetic TEF is measured first,and then,the TEF suppression rate and suppression efficiency are defined as optimization objectives,and the installation location of the FCL and its impedance parameters as optimization *** test the proposed method,two-terminal and four-terminal bipolar MMC-HVDC-Grids with single-pole-to-ground DC faults are modeled in the PSCAD/EMTDC so that the TEF data can be *** optimal FCLs’location and parameter values are determined through investigating the evolution paradigm of TEF along with changes of the FCL position and *** results prove that the selected parameters can effectively slow down the DC fault current rising rate,thus reducing the requirements on tripping current of the DC breakers.

关键词： MMC-HVDC-Grid TEF FCL DC fault protection optimal allocation

NiCo_(2)O_(4) hollow microsphere-mediated ultrafast peroxymonosulfate activation for dye degradation

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Chinese Chemical Letters 2021年第8期32卷 2495-2498页

作者： Pengjia Ding Jianrui Niu Fengqin Chang zhuang he Thomas Wagberg Zaixing Li Guangzhi Hu College of Environmental Science and Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environmental ScienceYunnan UniversityKunming 650504China Department of Physics Umea UniversityUmeå90187Sweden

Morphology and dispersity are key factors for activating peroxymonosulfate(PMS).In this study,we designed a recyclable open-type NiCo_(2)O_(4) hollow microsphere via a simple hydrothermal method with the assistance of an NH_(3) *** physical structure and chemical properties were characterized using techniques such as scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray diffraction(XRD),N2 adsorption and X-ray photoelectron spectroscopy(XPS).The test results confirm that the inner and outer surfaces of open-type NiCo_(2)O_(4) hollow-sphere can be efficiently utilized because of the hole on the surface of the catalyst,which can minimize the diffusion resistance of the reactants and *** optimized conditions,the total orga nic carbon(TOC) removal efficiency of rhodamine B(RhB) can reach up to 80% in 40 min,which is almost 50% shorter than the reported *** reactive radicals were identified and the proposed reaction mechanism was well ***,the disturbances of HCO_(3)^(-),NO_(3)^(-),Cl^(-)and H_(2) PO_(4)^(-)were further *** a result,HCO_(3)-and NO_(3)-suppressed the reaction while Cl-and H_(2) PO4-had a double effect on reaction.

关键词： Open-type sphere Hollow NiCo_(2)O_(4) Vesicle Inner and outer surface Ultra peroxymonosulfate activation

Investigation for the transcultural self-efficacy of nurses in Guizhou,China

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International Journal of Nursing Sciences 2020年第2期7卷 191-197页

作者： Juan Li Bei Wu zhuang he Jiru Liu Rong Xiao Yong Luo Guizhou Provincial People’s Hospital Gui ZhouChina Rory Meyers College of Nursing New York UniversityNew YorkUSA School of Nursing Guizhou UniversityGui ZhouChina School of Nursing Guizhou University of Traditional Chinese MedicineGui ZhouChina RN Saint Agnes HospitalBaltimoreMDUSA Chongqing Population and Family Planning Science and Technology Research Institute ChongqingChina

Aim:As conflict caused by cultural diversity among patients in China continues to rise,hospitals are in urgent need for improvement of transcultural efficacy among *** study aims to evaluate the transcultural self-efficacy of nurses working in the tertiary general hospital in Guizhou Province,an ethnic minority region in western China,and to identify whether nurses'demographic characteristics affect their transcultural ***:We used the Chinese version of the Transcultural Self-Efficacy Tool(TSET-CV)to survey 1,190 inservice ***:Results showed that the level of transcultural self-efficacy of the nurses was generally moderate;few of the nurses had high or low transcultural *** nurses'transcultural self-efficacy was affected by demographic variables,including age,marital status,employment type,income,work experience,and whether or not they were head *** a stable work environment,a stable marriage,a good educational background,and a high-ranked professional title were associated with increased transcultural ***:Nursing administrators in hospitals should offer continuing education on transcuitural nursing according to nurses'demographic characteristics and the SEST scores.

关键词： China General hospitals Minority groups Nurses Self efficacy Surveys and questionnaires Transcultural nursing

High-Speed Railway Train Timetable Conflict Prediction Based on Fuzzy Temporal Knowledge Reasoning

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Engineering 2016年第3期2卷 366-373页

作者： he zhuang Liping Feng Chao Wen Qiyuan peng Qizhi Tang School of.Transpfrtation anfl Logistics S outhwestJiaotong University Chengclu 610031 China China Railway Corporation Beijing 100844. China National United Engineering Laboratory of Integrated and Intelligent Transportation SouthwestJiaotong University Chengdu 610031. China Depamnent of Civil and Environmental Engineering University of Waterloo. Waterloo N2L 3G I Canada

Trains are prone to delays and deviations from train operation plans during their operation because of internal or external disturbances. Delays may develop into operational conflicts between adjacent trains as a result of delay propagation, which may disturb the arrangement of the train operation plan and threaten the operational safety of trains. Therefore, reliable conflict prediction results can be valuable references for dispatchers in making more efficient train operation adjustments when conflicts occur. In contrast to the traditional approach to conflict prediction that involves introducing random disturbances, this study addresses the issue of the fuzzification of time intervals in a train timetable based on historical statistics and the modeling of a high-speed railway train timetable based on the concept of a timed Petri net. To measure conflict prediction results more comprehensively, we divided conflicts into potential conflicts and certain conflicts and defined the judgment conditions for both. Two evaluation indexes, one for the deviation of a single train and one for the possibility of conflicts between adjacent train operations, were developed using a formalized computation method. Based on the temporal fuzzy reasoning method, with some adjustment, a new conflict prediction method is proposed, and the results of a simulation example for two scenarios are presented. The results prove that conflict prediction after fuzzy processing of the time intervals of a train timetable is more reliable and practical and can provide helpful information for use in train operation adjustment, train timetable improvement, and other purposes.

关键词： High-speed railway Train timetable Conflict prediction Fuzzy temporal knowledge reasoning

高速铁路列车运行调整的模型及其策略优化方法

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中国铁道科学 2017年第2期38卷 118-126页

作者：庄河何世伟戴杨铖西南交通大学交通运输与物流学院四川成都610031 中国铁路总公司运输局北京100844 北京交通大学交通运输学院北京100044

在分析高速铁路列车运行调整决策特点的基础上,针对高速铁路列车运行调整的传统优化模型在求解效率方面存在的问题,以相邻且存在冲突列车所在的位置为状态,行车调度员可采取的调整措施为行动,列车加权总晚点时间为调度员采取行动所获得... 详细信息

在分析高速铁路列车运行调整决策特点的基础上,针对高速铁路列车运行调整的传统优化模型在求解效率方面存在的问题,以相邻且存在冲突列车所在的位置为状态,行车调度员可采取的调整措施为行动,列车加权总晚点时间为调度员采取行动所获得的报酬,构建高速铁路列车运行调整的马氏决策过程模型;分析高速铁路列车运行调整决策过程最优策略的结构,给出采取列车顺晚开行和越行调整等行动的最优策略条件,基于列车的越行矩阵、到开时刻矩阵、最小停站时间矩阵和区间标准运行时间矩阵的定义,采用极大加代数和矩阵推算列车到发时刻,并据此设计模型求解的策略优化方法。结合某高速铁路区段的实例计算结果表明:给出的模型和策略优化方法能取得较人工调整方法更好的优化效果,较数学模型优化方法可提高求解效率,从而验证了高速铁路列车运行调整的马氏决策过程模型和策略优化方法的有效性。

关键词：高速铁路列车运行调整策略优化方法马氏决策过程模型极大加代数矩阵方法

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试论历史档案资源的空间分布特点及其成因

学海 2010年第1期 185-190页

作者：何庄中国人民大学信息资源管理学院副教授北京100872

本文从空间分布的整体状况、空间分布的国内格局、空间分布的载体特征和类型特点四个方面对我国历史档案资源的空间分布特征进行了系统地探讨,并在此基础上揭示了这些特征形成的复杂的历史文化原因。

关键词：历史档案空间分布特点

论魏晋南北朝的文论之“清”——兼及陶渊明的品第

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中国人民大学学报 2007年第2期21卷 120-126页

作者：何庄中国人民大学档案学院

“清”是具有深厚文化底蕴的中国哲学和美学范畴。魏晋南北朝时期是哲学之“清”转化为审美之“清”的关键时期,玄学本体论和玄学影响下的士人“清谈”对审美趣味产生了全方位的影响。玄学不同发展阶段的观点也影响了魏晋南北朝时期“... 详细信息

“清”是具有深厚文化底蕴的中国哲学和美学范畴。魏晋南北朝时期是哲学之“清”转化为审美之“清”的关键时期,玄学本体论和玄学影响下的士人“清谈”对审美趣味产生了全方位的影响。玄学不同发展阶段的观点也影响了魏晋南北朝时期“清”审美趣味的细微差异,形成了前后两个阶段文论同中有异的格局,前期以“清省”为主,而后期以“清丽”为主。

关键词：玄学清清省清丽陶渊明品第文论魏晋南北朝时期

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晋商票号文书档案及其管理初探

档案学通讯 2019年第6期 94-99页

作者：何庄中国人民大学信息资源管理学院

晋商票号的文书档案中,账簿是其经营的基本档案,主要通过分号定期编制"月清册"和"年总结"向总号报告的制度,对账簿进行管理。书信是其信息联通的重要文书,通过书信的编号、誊录、登记、寄送和归档等环节进行管理。合约是其创立时重要的... 详细信息

晋商票号的文书档案中,账簿是其经营的基本档案,主要通过分号定期编制"月清册"和"年总结"向总号报告的制度,对账簿进行管理。书信是其信息联通的重要文书,通过书信的编号、誊录、登记、寄送和归档等环节进行管理。合约是其创立时重要的契约文书,号规是其经营过程中的制度规范。它们涵盖了票号管理活动的各个方面,在票号经营中发挥了不可或缺的作用。

关键词：晋商票号文书文档管理

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清美意象生成的文化原型分析

中国人民大学学报 2005年第3期19卷 127-133页

作者：何庄中国人民大学信息资源管理学院北京100872

对清淡美的崇尚,是唐代中期以后中国士大夫阶层一种普遍的审美心理。本文借助原型批评理论,从远古社会的特点和原始的自然崇拜入手,探寻这一普遍审美心理的核心意象(水、玉、月)生成的过程与原因,揭示这一影响深远的审美心理的深层文化... 详细信息

对清淡美的崇尚,是唐代中期以后中国士大夫阶层一种普遍的审美心理。本文借助原型批评理论,从远古社会的特点和原始的自然崇拜入手,探寻这一普遍审美心理的核心意象(水、玉、月)生成的过程与原因,揭示这一影响深远的审美心理的深层文化蕴涵。

关键词：水玉月清美