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液固两相流对高压活动弯头的冲蚀磨损研究

润滑与密封 2024年第8期49卷 132-140页

作者：闫冲冲华剑长江大学机械工程学院湖北荆州434023 长江大学机械结构强度与振动研究所湖北荆州434023

为探究水力压裂作业中各因素对活动弯头的冲蚀磨损规律,基于液固两相流理论,利用FLUENT软件研究压裂液流速、颗粒质量流量、颗粒直径、安装角度、公称直径、连接长度、曲率半径对活动弯头冲蚀速率的影响。结果表明:活动弯头易冲蚀区域... 详细信息

为探究水力压裂作业中各因素对活动弯头的冲蚀磨损规律,基于液固两相流理论,利用FLUENT软件研究压裂液流速、颗粒质量流量、颗粒直径、安装角度、公称直径、连接长度、曲率半径对活动弯头冲蚀速率的影响。结果表明:活动弯头易冲蚀区域主要集中在弯头外侧,其最大冲蚀速率和平均冲蚀速率随流速、颗粒质量流量、颗粒直径的增大而增大,随安装角度、公称直径的增大整体上逐渐减小,安装角度位于90°~180°时,最大冲蚀速率和平均冲蚀速率较小且变化平缓;随曲率半径的增大,最大冲蚀速率整体上先减小后增大,平均冲蚀速率逐渐减小;连接长度对最大冲蚀速率和平均冲蚀速率的影响较小。研究表明,压裂液流速是导致冲蚀速率增加的主要因素,通过合理调整压裂液流速可以大大降低活动弯头的冲蚀磨损。该研究结果可为活动弯头的现场使用、冲蚀防护、结构改进及优化提供参考。

关键词：压裂液液固两相流冲蚀磨损活动弯头冲蚀速率数值模拟

基于解析二阶盲辨识的结构工作模态分析及真假模态区分

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工程力学 2024年第1期41卷 249-256页

作者：李涧鸣包腾飞周喜武高瑾瑾顾昊河海大学水文水资源与水利工程科学国家重点实验室南京210098 河海大学水利水电学院南京210098 三峡大学水利与环境学院宜昌443002 江苏省水利工程科技咨询股份有限公司南京210029 水利部交通运输部国家能源局南京水利科学研究院南京210029

自动获取运行中的模态参数对于大型土木结构的健康状态实时在线监测具有重要意义。针对现有方法模态分辨困难的问题,提出了一种基于解析二阶盲辨识的工作模态分析方法,并相应提出了真假模态区分方法以实现模态参数自动识别。与传统方法... 详细信息

自动获取运行中的模态参数对于大型土木结构的健康状态实时在线监测具有重要意义。针对现有方法模态分辨困难的问题,提出了一种基于解析二阶盲辨识的工作模态分析方法,并相应提出了真假模态区分方法以实现模态参数自动识别。与传统方法不同,该方法无需引入稳定图,可直接从结构振动响应中有效分离出各阶模态响应。通过构造模态特征指标和K均值聚类实现真假模态自动区分,并采用频域参数拟合法估计模态参数。通过8自由度数值算例和混凝土重力拱坝工程实例对该文方法效果进行了验证。结果表明:该方法具有较好的模态自动分离和筛选能力,对固有频率、阻尼比和振型的识别精度均较高,尤其对于密集模态的识别具有显著优势。

关键词：结构健康监测模态分析二阶盲辨识自动识别混凝土坝

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Expert consensus on the diagnosis and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children

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World Journal of Pediatrics 2024年第9期20卷 901-914页

作者： Ying-Shuo Wang Yun-Lian Zhou Guan-Nan Bai Shu-Xian Li Dan Xu Li-Na Chen Xing Chen Xiao-Yan Dong Hong-Min Fu Zhou Fu Chuang-Li Hao jian-Guo Hong En-Mei Liu Han-Min Liu Xiao-Xia Lu Zheng-Xiu Luo Lan-Fang Tang Man Tian Yong Yin Xiao-Bo Zhang jian-hua Zhang Hai-Lin Zhang De-Yu Zhao Shun-Ying Zhao Guo-Hong Zhu Ying-Xue Zou Quan Lu Yuan-Yuan Zhang Zhi-Min Chen Department of Pulmonology Children’s HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou 310052China Department of Child Health Care Children’s HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou 310052China Department of Pediatric Pulmonology and Immunology West China Second University HospitalSichuan UniversityChengdu 610041China Department of Pediatrics Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021China Department of Pulmonology Shanghai Children’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200062China Department of Pulmonary and Critical Care Medicine Kunming Children’s HospitalKunming 650034China Department of Respiratory Medicine Children’s Hospital of Chongqing Medical UniversityChongqing 400014China Department of Pulmonology Children’s Hospital of Soochow UniversitySuzhou 215003China Department of Pediatrics Shanghai General Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghai 200080China Department of Respiratory Medicine Wuhan Children’s HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430015China Department of Respiratory Medicine Children’s Hospital of Nanjing Medical UniversityNanjing 210008China Department of Respiratory Medicine Shanghai Children’s Medical CenterShanghai Jiao Tong University School of MedicineShanghai 200127China Department of Respiratory Medicine Children’s Hospital of Fudan UniversityShanghai 201102China Department of Pediatric Pulmonology Xinhua HospitalShanghai Jiaotong University School of MedicineShanghai 201102China Department of Pediatric Respiratory Medicine The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325027China National Clinical research Center for Respiratory Diseases Beijing Children’s HospitalCapital Medical UniversityBeijing 100045China Departmen

Background Mycoplasma pneumoniae(***)is a significant contributor to community-acquired pneumonia among *** 1968,when a strain of *** resistant to macrolide antibiotics was initially reported in Japan,macrolide-resistant ***(MRMP)has been documented in many countries worldwide,with varying incidence *** infections lead to a poor response to macrolide antibiotics,frequently resulting in prolonged fever,extended antibiotic treatment,increased hospitalization,intensive care unit admissions,and a significantly higher proportion of patients receiving glucocorticoids or second-line *** 2000,the global incidence of MRMP has gradually increased,especially in East Asia,which has posed a serious challenge to the treatment of *** infections in children and attracted widespread attention from ***,there is still no global consensus on the diagnosis and treatment of MRMP in *** We organized 29 Chinese experts majoring in pediatric pulmonology and epidemiology to write the world’s first consensus on the diagnosis and treatment of pediatric MRMP pneumonia,based on evidence *** evidence searches and reviews were conducted using electronic databases,including PubMed,Embase,Web of Science,CNKI,Medline,and the Cochrane *** used variations in terms for“macrolide-resistant”,“Mycoplasma pneumoniae”,“MP”,“***”,“pneumonia”,“MRMP”,“lower respiratory tract infection”,“Mycoplasma pneumoniae infection”,“children”,and“pediatric”.Results Epidemiology,pathogenesis,clinical manifestations,early identification,laboratory examination,principles of antibiotic use,application of glucocorticoids and intravenous immunoglobulin,and precautions for bronchoscopy are *** and rapid identification of gene mutations associated with MRMP is now available by polymerase chain reaction and fluorescent probe techniques in respiratory *** the resistance rate to mac

关键词： Child Macrolide-resistant Mycoplasma pneumoniae Recommendation Diagnosis Treatment

Perfection of Perovskite Grain Boundary Passivation by Rhodium Incorporation for Efficient and Stable Solar Cells

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Nano-Micro Letters 2020年第9期12卷 203-213页

作者： Wei Liu nanjing Liu Shilei Ji Hongfeng hua Yuhui Ma Ruiyuan Hu jian Zhang Liang Chu Xing’ao Li Wei huang institute of Advanced Materials and New Energy Technology Engineering Laboratory of jiangsu Province Nanjing University of Posts and Telecommunications(NUPT)Nanjing 210023People’s Republic of China Shaanxi institute of Flexible Electronics Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China Guangdong Provincial Key Lab of Nano‑Micro Materials research School of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055People’s Republic of China

Organic cation and halide anion defects are omnipresent in the perovskite films,which will destroy perovskite electronic structure and downgrade the properties of *** passivation in halide perovskites is crucial to the application of solar ***,tiny amounts of trivalent rhodium ion incorporation can help the nucleation of perovskite grain and passivate the defects in the grain boundaries,which can improve efficiency and stability of perovskite solar *** first-principle calculations,rhodium ion incorporation into the perovskite structure can induce ordered arrangement and tune *** experiment,rhodium ion incorporation with perovskite can contribute to preparing larger crystalline and uniform film,reducing trap-state density and enlarging charge carrier *** optimizing the content of 1% rhodium,the devices achieved an efficiency up to 20.71% without obvious hysteresis,from 19.09% of that pristine *** addition,the unencapsulated solar cells maintain 92% of its initial efficiency after 500 h in dry *** work highlights the advantages of trivalent rhodium ion incorporation in the characteristics of perovskite solar cells,which will promote the future industrial application.

关键词： Perovskite solar cells Grain boundary passivation Rhodium incorporation

Local scour by multiple slit-type energy dissipaters

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Journal of Hydrodynamics 2020年第6期32卷 1221-1224页

作者： Li Yao jian-hua wu College of Water Conservancy and Ecological Engineering Nanchang Institute of TechnologyNanchang330099China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China

Energy dissipation and scour control are all the key issues for the design of hydraulic *** the basis of the high energy dissipation for the multiple slit-type energy dissipaters(M-STED)developed by the authors,in this work,the characteristics of the scour hole for the M-STED were experimentally investigated through three sets of those physical models with five cases and a scour hole form index was *** results show that,the M-STED results in not only the high energy dissipation but also the mild upstream slope of the scour hole thanks to the scour hole form index of larger than 0.5,which is in favor of the safety of the release works.

关键词： Energy dissipation scour scour hole form index multiple slit-type energy dissipater

FLOW REGIMES BELOW AERATORS FOR DISCHARGE TUNNELS

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Journal of Hydrodynamics 2012年第3期24卷 378-382页

作者： MA Fei wu jian-hua College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

The flow regimes below an aerator influence directly the air entrainment and the cavitation damage control. Based on the theoretical considerations, the experiments of the aerator for a discharge tunnel were conducted, and the relationships between the flow regime and hydraulic and geometric parameters were investigated. The results showed that, there are two kinds of threshold values for the flow regime conversions. One is Fr1-2 standing for the conversion from the fully filled cavity to the partially filled cavity, and the other is Fr2-3 which shows the change from the partially filled cavity to the net air cavity. Two empirical expressions were obtained for the conversions of the flow regimes, which can be used in the designs of the aerators.

关键词： aerator discharge tunnel flow regime filling water jet length

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基于机场跑道饱和度的空中交通阻抗建模

科学技术与工程 2024年第20期24卷 8797-8803页

作者：徐满高华键王建王炜刘文芝综合交通规划数字化实验室北京100028 东南大学交通学院南京211102 交通运输部规划研究院北京100028

通过对空中交通阻抗基本要素的解析,参考道路交通BPR(Bureau of Public Road)阻抗函数,提出一种综合考虑起飞机场和降落机场跑道饱和度的空中交通阻抗函数模型以研究空中交通阻抗问题,为空中交通阻抗分析提供新的研究思路。采用南京禄... 详细信息

通过对空中交通阻抗基本要素的解析,参考道路交通BPR(Bureau of Public Road)阻抗函数,提出一种综合考虑起飞机场和降落机场跑道饱和度的空中交通阻抗函数模型以研究空中交通阻抗问题,为空中交通阻抗分析提供新的研究思路。采用南京禄口机场-北京首都机场的航班数据进行拟合分析,对模型参数进行标定。根据有无流量控制分别给出了仅考虑降落机场跑道饱和度模型的拟合结果并进行了参数检验,同时进一步与综合考虑起降机场跑道饱和度模型的拟合优度指标进行对比分析。结果显示:综合模型在无流控情况下精度提升了11.9%,有流控情况下精度提升了16.7%,可以为空中交通管理提供参考。

关键词：空中交通管理交通阻抗模型机场跑道饱和度拟合优度检验

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基于多特征融合的水工闸门剩余寿命预测

长江科学院院报 2024年第2期41卷 188-197页

作者：杨涛张钰奇付春健赵华东郑州大学机械与动力工程学院郑州450001 河南省智能制造研究院郑州450001

剩余寿命预测对保证复杂结构运行安全具有重大意义,为了提高水工闸门剩余寿命预测精度,提出了一种多特征信息融合的闸门剩余寿命预测方法。首先,采用Gamma过程模拟闸门锈蚀演化过程,通过数值仿真获得闸门因锈蚀引起的应力、自振频率、... 详细信息

剩余寿命预测对保证复杂结构运行安全具有重大意义,为了提高水工闸门剩余寿命预测精度,提出了一种多特征信息融合的闸门剩余寿命预测方法。首先,采用Gamma过程模拟闸门锈蚀演化过程,通过数值仿真获得闸门因锈蚀引起的应力、自振频率、干湿模态振型等特征参数的退化过程。其次,综合考虑单调性和离散性对特征参数进行筛选,并基于主成分分析法进行特征融合构建健康因子;进一步采用非线性维纳过程对闸门退化过程进行建模,利用粒子滤波方法预测其剩余寿命。最后,结合工程实例及有限元仿真验证了所提方法的可靠性和有效性。结果表明,融合多信息的方法能更加充分地反映闸门的退化状态,预测精度评价指标均方根RMSE为1.3955,平均绝对误差MAE为1.2628,方差绝对误差VAE为0.3528,说明预测达到了较高精度,可为闸门的健康管理和安全评估提供依据。

关键词：水工钢闸门信息融合剩余寿命预测粒子滤波

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Nitric oxide donating anti-glaucoma drugs:advances and prospects

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Chinese Journal of Natural Medicines 2020年第4期18卷 275-283页

作者： MAO Yu-Jie wu jian-Bing yang Ze-Qiu ZHANG Yi-hua huaNG Zhang-jian State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic DiseasesCenter of Drug DiscoveryChina Pharmaceutical UniversityNanjing 210009China

Glaucoma is a disease that causes irreversible blindness. Reducing intraocular pressure(IOP) is the main treatment at present. Nitric oxide(NO), an endogenous gas signaling molecule, can increase aqueous humor outflow facility, inhibit aqueous humor production thereby reducing IOP, as well as regulate eye blood flow and protect the optic nerve. Therefore, NO donating antiglaucoma drugs have broad research prospects. In this review, we summarize NO-mediated therapy for glaucoma, and the state of the art of some NO donating molecules, including latanoprostene bunod in market and some other candidate compounds, for the intervention of glaucoma, as well as prospects and challenges ahead in this field.

关键词： Nitric oxide Glaucoma Intraocular pressure Trabecular meshwork Prostaglandin analogues