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Protection and Control of Modern Power Systems 2023年第3期8卷 80-96页

作者： Jinmu Lai Xin Yin Xianggen Yin jiaxuan hu Fan Xiao School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001Henan ProvincePeople’s Republic of China School of Automation Wuhan University of TechnologyWuhan 430070Hubei ProvincePeople’s Republic of China School of Electrical and Electronic Engineering Huazhong University of Science and Technology(HUST)Wuhan 430074Hubei ProvincePeople’s Republic of China State Grid hubei Electric Power Research Institute Wuhan 430077Hubei ProvincePeople’s Republic of China

The power router(PR)is a promising piece of equipment for realizing multi-voltage level interconnection and flex-ible power control in the future distribution power *** this paper,a hybrid PR(HPR)topology based on power-frequency transformer electromagnetic coupling with converters is proposed for the medium distribution power *** power-frequency transformer is used to undertake power transmission,voltage conversion,and other main tasks,while the power electronic converters are combined to achieve active *** magnetic and electrical circuit models are established to help discuss the operating principle of the proposed ***,the power flow and control principle of the HPR in different operating conditions are analyzed,with the control system design scheme *** theoretical analysis results are verified by MATLAB/Simulink+Plecs simulation and a controller hardware-in-the-loop study,as well as a down-scale experimental test,indicating that the proposed HPR is flexible in active voltage support and current control.

关键词： Power router Power-frequency transformer Power electronic converter Hybrid Working mechanism

Temporal and spatial evolution of global major grain trade patterns

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Journal of Integrative Agriculture 2024年第3期23卷 1075-1086页

作者： Ziqi Yin jiaxuan hu Jing Zhang Xiangyang Zhou Lingling Li Jianzhai Wu Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081China Institute of Scientific and Technical Information of China Beijing 100038China Zibo Agricultural Science Research Institute Zibo 255000China Zibo Institute for Digital Agriculture and Rural Research Zibo 255000China

The complex and volatile international landscape has significantly impacted global grain supply security. This study uses a complex network analysis model to examine the evolution and trends of the global major grain trade from 1990 to 2020, focusing on network topology, centrality ranking, and community structure. There are three major findings. First, the global major grain trade network has expanded in scale, with a growing emphasis on diversification and balance. During the study period, the United States, Canada, China, and Brazil were the core nodes of the network. Grain-exporting countries were mainly situated in Asia, the Americas, and Europe, and importing countries in Asia, Africa, and Europe. Second, a significant increase in the number of high centrality countries with high export capacity occurred, benefiting from natural advantages such as fertile land and favorable climates. Third, the main global grain trade network is divided into four communities, with the Americas-Europe community being the largest and most widespread. The formation of the community pattern was influenced by geographic proximity, driven by the core exporting countries. Therefore, the world needs to enhance the existing trade model, promote the multi-polarization of the grain trade network, and establish a global vision for the future community. Countries and regions should participate actively in global grain trade security governance and institutional reform, expand trade links with other countries, and optimize import and export policies to reduce trade risks.

关键词： grain trade pattern evolution complex network

Confounding amplifies the effect of environmental factors on COVID-19

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Infectious Disease Modelling 2024年第4期9卷 1163-1174页

作者： Zihan Hao Shujuan hu Jianping huang jiaxuan hu Zhen Zhang Han Li Wei Yan College of Atmospheric Sciences Lanzhou UniversityLanzhoum730000China Collaborative Innovation Center for Western Ecological Safety College of Atmospheric SciencesLanzhou UniversityLanzhou730000China

The global COVID-19 pandemic has severely impacted human health and socioeconomic development,posing an enormous public health *** research has been conducted into the relationship between environmental factors and the transmission of ***,numerous factors influence the development of pandemic outbreaks,and the presence of confounding effects on the mechanism of action complicates the assessment of the role of environmental factors in the spread of *** estimation of the role of environmental factors without removing the confounding effects will be *** overcome this critical problem,we developed a Double Machine Learning(DML)causal model to estimate the debiased causal effects of the influencing factors in the COVID-19 outbreaks in Chinese *** experiments revealed that the traditional multiple linear regression model overestimated the impact of environmental *** factors are not the dominant cause of widespread outbreaks in China in *** addition,by further analyzing the causal effects of environmental factors,it was verified that there is significant heterogeneity in the role of environmental *** causal effect of environmental factors on COVID-19 changes with the regional *** is therefore recommended that when exploring the mechanisms by which environmental factors influence the spread of epidemics,confounding factors must be handled carefully in order to obtain clean quantitative *** study offers a more precise representation of the impact of environmental factors on the spread of the COVID-19 pandemic,as well as a framework for more accurately quantifying the factors influencing the outbreak.

关键词： COVID-19 Environmental factors Causal analysis Double machine learning

Impact of Onset Time, Number, Type, and Sequence of Extrahepatic Organ Failure on Prognosis of Acute-on-chronic Liver Failure

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Journal of Clinical and Translational Hepatology 2024年第3期12卷 257-265页

作者： Shaotian Qiu Qian Zhang jiaxuan hu Lewei Wang Rui Chen Yingying Cao Fang Liu Zhenjun Yu Caiyan Zhao Liaoyun Zhang Wanhua Ren Shaojie Xin Yu Chen Zhongping Duan Tao Han The School of Medicine Nankai UniversityTianjinChina Department of Gastroenterology and Hepatology Tianjin Union Medical Center Affiliated to Nankai UniversityTianjinChina Department of Gastroenterology and Hepatology Tianjin Union Medical CenterTianjinChina Tianjin Medical University TianjinChina Department of Gastroenterology and Hepatology Tianjin Union Medical Center of Tianjin Medical UniversityTianjinChina Department of Hepatology and Gastroenterology The Third Central Clinical College of Tianjin Medical UniversityTianjinChina Department of Infectious Disease The Third Hospital of Hebei Medical UniversityShijiazhuangHebeiChina Department of Infection Disease First Hospital of Shanxi Medical UniversityTaiyuanShanxiChina Infectious Department of Shandong First Medical University Affiliated Shandong Provincial Hospital JinanShandongChina Liver Failure Treatment and Research Center The Fifth Medical Center of Chinese PLA General HospitalBeijingChina Liver Disease Center(Difficult&Complicated Liver Diseases and Artificial Liver Center) Beijing You’an Hospital Affiliated to Capital Medical UniversityBeijingChina

Background and Aims:The impact of the characteristics of extrahepatic organ failure(EHOF)including the onset time,number,type,and sequence on the prognosis of acute-onchronic liver failure(ACLF)patients remains *** study aimed to identify the association between the characteristics of EHOF and the prognosis of ACLF ***:ACLF subjects enrolled at six hospitals in China were included in the *** risk of mortality based on the characteristics of EHOF was *** of study groups was compared by Kaplan–Meier analysis and log-rank ***:A total of 736 patients with ACLF were *** was observed in 402 patients(54.6%),of which 295(73.4%)developed single EHOF(SEHOF)and 107(26.6%)developed multiple EHOF(MEHOF).The most commonly observed EHOF was coagulation failure(47.0%),followed by renal(13.0%),brain(4.9%),respiratory(4.3%),and circulatory(2.3%)*** analysis found that MEHOF or SEHOF patients with brain failure had a worse ***,no significant outcome was found in the analysis of the effect of onset time and sequence of failed organs on *** were further divided into three risk subgroups by the EHOF ***–Meier analysis showed that risk stratification resulted in the differentiation of patients with different risks of mortality both in the training and validation ***:The mortality of ACLF patients was determined by the number and type,but not the onset time and sequence of *** stratification applicable to clinical practice was established.

关键词： Extrahepatic organ failure Acute-on-chronic liver failure Prognosis Brain failure

《2024年亚太肝病学会临床实践指南:慢加急性肝衰竭患者急性肾损伤的管理》摘译

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临床肝胆病杂志 2024年第8期40卷 1575-1578页

作者：胡家轩韩涛南开大学人民医院消化(肝病)科天津300121

慢加急性肝衰竭是一种以器官衰竭快速进展为特征的综合征,短期病死率高。肾脏是其最容易受累的肝外器官之一。近期发布的《2024年亚太肝病学会临床实践指南:慢加急性肝衰竭患者急性肾损伤的管理》对慢加急性肝衰竭患者急性肾损伤的早期... 详细信息

慢加急性肝衰竭是一种以器官衰竭快速进展为特征的综合征,短期病死率高。肾脏是其最容易受累的肝外器官之一。近期发布的《2024年亚太肝病学会临床实践指南:慢加急性肝衰竭患者急性肾损伤的管理》对慢加急性肝衰竭患者急性肾损伤的早期诊断、病理生理学、预防和管理提出相关共识声明和推荐意见,同时也指出未来需要开展更多高质量的研究。

关键词：慢加急性肝功能衰竭急性肾损伤诊疗准则

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关于推理公式流量是否为设计重现期最大流量的数学模型检验探讨

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给水排水 2024年第3期50卷 70-76页

作者：王晟胡家璇同济大学环境科学与工程学院教育部长江水环境重点实验室上海200092

采用数学模型计算雨水设计流量方法发展一直受到缺乏雨水设计数学建模规范性方法的制约。有技术路线是根据推理公式建模,即建立和推理公式等效的模型。推理公式的作用是计算设计重现期最大降雨径流量,其可靠性依赖理论假设和参数取值。... 详细信息

采用数学模型计算雨水设计流量方法发展一直受到缺乏雨水设计数学建模规范性方法的制约。有技术路线是根据推理公式建模,即建立和推理公式等效的模型。推理公式的作用是计算设计重现期最大降雨径流量,其可靠性依赖理论假设和参数取值。基于教材上推理公式案例的研究表明,固定产流系数-漫流模型不能和推理公式等效。扣损法产流-漫流模型中28/31实现了和推理公式等效,用等效模型求设计重现期最大流量并与推理公式结果作比较发现,支撑推理公式的实质性假设在25个情境下被证伪,在3个情境下成立,即理论上推理公式可求得设计重现期最大流量,然而它们中只有1个求得,原因在于仅靠经验难以周全考虑降雨-漫流-产流过程来对推理公式参数取值。推理公式不能保证求得设计重现期最大流量,因此根据推理公式建模的技术路线需商榷。

关键词：城市雨水排水雨水设计流量推理公式雨水数学模型

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2022年山东省宫颈癌筛查项目结果分析

中华肿瘤防治杂志 2024年第10期31卷 602-607页

作者：胡佳璇薛付忠山东大学齐鲁医学院公共卫生学院山东济南250012 山东大学健康医疗大数据研究院山东济南250012 山东大学齐鲁医学院齐鲁医院山东济南250012

目的了解2022年山东省35~64岁适龄女性宫颈癌及癌前病变的检出情况,为后续开展免费筛查项目及实现消除宫颈癌目标提供依据。方法本研究基于2022年山东省宫颈癌免费筛查项目,选取2022-01-01-2022-12-31间接受宫颈癌免费筛查的女性。研究... 详细信息

目的了解2022年山东省35~64岁适龄女性宫颈癌及癌前病变的检出情况,为后续开展免费筛查项目及实现消除宫颈癌目标提供依据。方法本研究基于2022年山东省宫颈癌免费筛查项目,选取2022-01-01-2022-12-31间接受宫颈癌免费筛查的女性。研究数据由山东省妇幼保健院汇总,数据来源于各县(市、区)妇幼保健机构季度报表,涵盖宫颈细胞学伯塞斯达系统(TBS)和宫颈病理等检查结果。本研究对筛查数据进行统计分析,并绘制各地市宫颈癌及癌前病变检出率地图。结果本研究共纳入参加山东省宫颈癌免费筛查项目的2887279名女性,结果显示,2022年山东省宫颈癌检出率为14.75/10万(426/2887279),癌前病变检出率为484.89/10万(14000/2887279)。TBS报告显示,山东省宫颈细胞学总体异常检出率为3.27%(94342/2887279),其中不典型鳞状上皮细胞(ASC-US)检出率最高为2.34%(67618/2887279)。威海市宫颈细胞学异常检出率最高为4.57%(1196/26158),东营市阴道镜异常检出率最高为71.28%(995/1396)。结论2022年山东省宫颈癌免费筛查项目取得了显著成效,仍需继续推广宫颈癌筛查工作,加大宫颈癌防治知识的宣传力度,扩大筛查覆盖范围,并鼓励适龄女性接种HPV疫苗。要进一步探索与中国国情相适应的宫颈癌消除策略,以降低宫颈癌的发病率和死亡率,从而提高女性的生存质量。

关键词：宫颈癌宫颈癌前病变筛查适龄女性女性卫生

《2021年美国肝病学会实践指导:腹水和肝肾综合征的诊断、评估和管理》摘译

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临床肝胆病杂志 2021年第11期37卷 2548-2549页

作者：胡家轩(译) 韩涛(审校) 南开大学人民医院消化肝病科天津300121

本实践指导是对2012年美国肝病学会(AASLD)慢性肝病患者腹水和肝肾综合征诊断、评估和管理指南的更新。与经过文献系统评价、证据质量和推荐建议强度的正式评级制定的指南不同,鉴于目前尚缺乏足够数量的随机对照试验来支持进行有意义的... 详细信息

本实践指导是对2012年美国肝病学会(AASLD)慢性肝病患者腹水和肝肾综合征诊断、评估和管理指南的更新。与经过文献系统评价、证据质量和推荐建议强度的正式评级制定的指南不同,鉴于目前尚缺乏足够数量的随机对照试验来支持进行有意义的系统评价和荟萃分析,该实践指导是在AASLD实践指南委员会监督下,基于专家小组的共识以及相关文献的系统回顾和分析,提出指导性声明建议。

关键词：肝硬化腹水肝肾综合征诊疗准则(主题)

微电网混合型联网变压器及其故障阻隔协调控制

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电力自动化设备 2023年第10期43卷 145-151,207页

作者：尹昕赖锦木尹项根王要强尹越胡家玄武汉理工大学自动化学院湖北武汉430070 郑州大学电气与信息工程学院河南郑州450001 华中科技大学电气与电子工程学院湖北武汉430074

交直流混合微电网(HMG)联网与优化运行中,常规工频变压器不具备短路故障阻隔和电压综合控制能力。对此,提出一种适用于HMG的混合型联网变压器(HIT),并构建新型基于混合型联网变压器的交直流混合微电网(HIT-HMG)。介绍了HIT拓扑结构并分... 详细信息

交直流混合微电网(HMG)联网与优化运行中,常规工频变压器不具备短路故障阻隔和电压综合控制能力。对此,提出一种适用于HMG的混合型联网变压器(HIT),并构建新型基于混合型联网变压器的交直流混合微电网(HIT-HMG)。介绍了HIT拓扑结构并分析其运行原理,构造新型三柱三绕组工频变压器进行电压等级变换和部分功率传输,由串联变流器实现HMG的电压和电流主动控制。对HIT及串联变流器进行数学建模,建立新型工频变压器的等效磁路模型和等效电路模型。考虑配电网不同位置与故障类型,提出HITHMG故障阻隔控制策略。对所提HIT及控制方案进行仿真和实验验证,结果表明通过控制HIT的串联绕组电压,可以阻隔中高压配电网故障对HMG的影响。

关键词：交直流混合微电网工频变压器变流器故障阻隔协调控制

基于电能路由器的配电网稳定运行与故障恢复分层能量优化

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电力自动化设备 2022年第4期42卷 154-164,171页

作者：杜云飞尹项根赖锦木王祯胡家玄于吉华中科技大学强电磁工程与新技术国家重点实验室湖北武汉430074 郑州大学电气工程学院河南郑州450001

为了解决目前基于电能路由器(EER)的配电网能量优化普遍缺乏对故障恢复的研究及能量路由损耗过大的问题,同时考虑稳定运行与故障恢复2种工况,提出了一种基于EER的配电网分层能量优化策略,其包括下层局域电网(E-LAN)内的能量优化以及上... 详细信息

为了解决目前基于电能路由器(EER)的配电网能量优化普遍缺乏对故障恢复的研究及能量路由损耗过大的问题,同时考虑稳定运行与故障恢复2种工况,提出了一种基于EER的配电网分层能量优化策略,其包括下层局域电网(E-LAN)内的能量优化以及上层广域电网(E-WAN)内的能量路由优化。对于稳定运行工况,提出了以最小化运行总成本为目标的E-LAN能量优化策略,以及以最小损耗就地消纳的E-WAN路由优化策略,路由优化策略在保障可再生能源就地消纳的同时,实现电能损耗最小化。对于故障恢复工况,提出了以最大化累计上网电量为目标的E-LAN能量优化策略,以及最小损耗多源协同的E-WAN路由优化策略,路由优化策略可在向关键负荷优先供电的同时,实现电能损耗最小化,并提升故障后负荷存活率。最后基于配电网分层网络模型进行仿真分析与对比,验证了所提能量优化策略的可行性、有效性和优越性。

关键词：电能路由器稳定运行故障恢复分层配电网能量优化路由优化关键负荷