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Thermal Performance Prediction in the Air Gap of a Rotor-Stator Configuration: Effects of Numerical Models

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Journal of Thermal Science 2020年第1期29卷 206-218页

作者： dang dinh-Dong PHAM Xuan-Tan NGUYEN Chi-Cong Department of Mechanical Engineering École de technologie supérieureMontrealQCCanada Hydro-Québec’s research institute VarennesQCCanada

This study is dedicated to a numerical investigation of convective heat transfer on the rotor surfaces of a rotor-stator configuration that is typically found in large *** computational fluid dynamics calculations with two turbulence modelling approaches are used to predict the flow structure and heat transfer in the air gap of the rotor-stator *** steady state mixing plane approach is employed at the interface to couple the rotor and stator *** show that the location of mixing plane interface in the air gap plays an important role in the prediction of heat transfer on the pole ***,it is indicated that the prediction of temperature distribution on the pole face is greatly affected by the turbulence models ***,through a comparison between the pure convective and conjugate heat transfer methodologies,it is shown that the inclusion of solid domain into the numerical model significantly improves the thermal prediction of the solid components of the machine.

关键词： hydro-generators electrical cooling mixing plane windage loss conjugate heat transfer

Remediation of soil and groundwater contaminated with organic chemicals using stabilized nanoparticles: Lessons from the past two decades

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Frontiers of Environmental Science & Engineering 2020年第5期14卷 83-102页

作者： Zhengqing Cai Xiao Zhao Jun duan Dongye Zhao Zhi dang Zhang Lin National Engineering Lab for High-concentration Refractory Organic Wastewater East China University of Science and TechnologyShanghai 200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China College of Water Resources&Civil Engineering China Agricultural UniversityBeijing 100083China Environmental Engineering Program Department of Civil EngineeringAuburn UniversityAuburnAL 36849USA School of Environment and Energy South China University of TechnologyGuangzhou 510006China

Due to improved soil deliverability and high reactivity,stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic *** large amounts of bench-and field-scale experimental data have demonstrated the potential of the innovative technology,extensive research results have also unveiled various merits and constraints associated different soil characteristics,types of nanoparticles and particle stabilization ***,this work aims to critically overview the fundamental principles on particle stabilization,and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and *** specific objectives are to:1)overview fundamental mechanisms in nanoparticle stabilization;2)summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals;3)update the latest knowledge on the transport and fate of stabilized nanoparticles;4)examine the merits and constraints of stabilized nanoparticles in environmental remediation applications;and 5)identify the knowledge gaps and furore research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and *** instructions of this invited special issue,this review is focused on contributions from our group(one of the pioneers in the subject field),which,however,is supplemented by important relevant works by *** knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.

关键词： Stabilized nanoparticle In-situ remediation Organic contaminant Soil remediation Groundwater Fate and transport

Antibiotic usage in surgical sperm retrievals among IVF centers

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Asian Journal of Andrology 2022年第6期24卷 633-638页

作者： Le dang Khoa Ngo dinh Trieu Vy Nguyen Minh Tai Loc Le Duc Thang dang Tuan Anh Nguyen Phuc Hieu Giang Huynh Nhu Nguyen dinh Tao Le Hoang David J Handelsman IVFTA Tam Anh General HospitalHo Chi Minh 700000Vietnam IVFTA Tam Anh General HospitalHa Noi 100000Vietnam IVF Center 16A Ha Dong HospitalHa Noi 100000Vietnam ANZAC Research Institute University of Sydney and Concord Repatriation General HospitalHospital RoadConcordNSW 2139Australia

Surgical sperm retrieval(SSR)is currently one of the most common procedures in in vitro fertilization(IVF).However,a gap between the guidelines and routine clinical practice regarding antibiotic use in sSR,which might lead to antibiotic resistance,is a challenging problem worldwide.A cross-sectional survey was conducted from May 1,2021,to July 15,2021,to investigate antibiotic usage by medical professionals when performing SSR in IVF centers in *** confidential questionnaire comprised 12 items,including characteristics of the study population,awareness of antimicrobial resistance,attitude toward prescribing antibiotics,and current practice of prescribing antibiotics when performing *** were completed by 30 of 45 registered IVF centers(66.7%).Among 67 physicians working at those centers,the age and work-experience years(mean±standard deviation[s.d.])were 38.6±6.6 years and 11.2±7.0 years,*** 60%of them held a degree in Obstetrics and Gynecology,and over four-fifths were *** respondents"often/very often/always"raised awareness of antimicrobial resistance to their patients(83.3%),but only half of them"often/occasionally"prescribed antibiotics to patients with SSR in cases where the prescription would be *** one-tenth of respondents followed the recommendation from the American Urological Association using"prophylaxis only"for SSR *** more invasive SSR,physicians tended to prescribe more complicated and sometimes inappropriate *** conclusion,antibiotic usage in SSR was not always appropriate among IVF *** studies may define specific recommendations for regimens,intervention strategies,and programs to promote appropriate antibiotic use for SSR patients among IVF specialists.

关键词： antibiotic usage in vitro fertilization prophylaxis surgical sperm retrieval treatment

Efficient adsorption of europium(Ⅲ)and uranium(Ⅵ)by titanate nanorings:Insights into radioactive metal species

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Environmental Science and Ecotechnology 2020年第2期2卷 76-85页

作者： Maosheng Zheng Haodong Ji Jun duan Chenyuan dang Xingmin Chen Wen Liu The Key Laboratory of Water and Sediment Sciences Ministry of EducationCollege of Environmental Sciences and EngineeringPeking UniversityBeijing100871China The Key Laboratory of Resources and Environmental Systems Optimization Ministry of EducationCollege of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing102206China The Beijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT) Peking UniversityBeijing100871China Beijing Engineering Research Center for Advanced Wastewater Treatment Department of Environmental EngineeringPeking UniversityBeijing100871China College of Environmental Science and Engineering Ocean University of ChinaQingdao266100China

Radioactive wastewater containing high concentration of radionuclides poses severe threats to ecosystem and human health,so efficient removal of these toxic heavy metals is urgently *** nanomaterials have been demonstrated good adsorbents for heavy metals due to ion exchange *** this study,titanate nanorings(TNRs)were synthesized using the facile hydrothermal-cooling *** TNRs were composed of sodium trititanate,with a chemical formula of Na_(0.66)H_(1.34)-Ti_(3)O_(7)·0.27H_(2)O and a Na content of 2.38 mmol/*** TNRs demonstrated sufficient adsorption performance to radionuclides europium(Eu)and uranium(U)***,even at a high initial concentration of 50 mg/L,86.5% and 92.6% of the two metal ions can be rapidly adsorbed by the TNRs within 5 min,and equilibrium was reached within 60 min at pH *** maximum adsorption capacity(Qmax)obtained by the Langmuir isotherm model was 115.3 mg/g for Eu(Ⅲ)and 282.5 mg/g for uranium U(Ⅵ)at pH 5,*** adsorption capacities of the two metals under various water chemical conditions were highly related to their *** exchange between metal cations and Na^(+) in the TNR interlayers was the dominant adsorption mechanism,and adsorption of U(Ⅵ)was more complicated because of the co-existence of various uranyl(UO_(2)^(2+))and uranyl-hydroxyl *** spent TNRs were effectively regenerated through an acid-base or ethylenediamine tetraacetic acid(EDTA)treatment and *** the large adsorption capacity and quick kinetic,TNRs are promising materials to remove radionuclides in environmental purification applications,especially emergent treatment of leaked radionuclides.

关键词： Titanate nanorings Ion exchange Radionuclides Species Adsorption

Introduction to the China-Vietnam Cooperation Project: A Comparative Study of the Holocene Sedimentary Evolution of the Yangtze and Red River Deltas

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Journal of Ocean University of China 2018年第6期17卷 1269-1271页

作者： YIN Ping PHUNG Van Phach TRAN dinh Lan DO Huy Cuong BUI Van Vuong duan Xiaoyong Key Laboratory of Marine Environmental Geology Ministry of Natural Resources Qingdao Institute of Marine Geology Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology Institute of Marine Geology and Geophysics Vietnam Academy of Science and Technology Institute of Marine Environment and Resources Vietnam Academy of Science and Technology

Both China and Vietnam confront the challenges of natural geohazards and environmental changes in their deltas and coastal zones due to rapid urbanization, economic development, and the impacts of global climate change. China and Vietnam initiated a comparative study of the Holocene sedimentary evolution of the Yangtze River Delta(YRD) and Red River Delta(RRD) for the period 2015–2018 in order to improve the understanding of the two delta evolution histories in the Holocene. Previous investigative data of the two rivers, onshore delta plains, and offshore subaqueous deltas have been explored and reinterpreted. New data gleaned from boreholes, piston cores, shallow seismic and hydrodynamic sources have been collected from the offshore YRD and the East China Sea inner shelf, and surface sediments and short cores have been collected from the RRD near-shore areas. Six focal areas of the joint project have been defined for comparative studies of the two deltas, including morphological development, sequential stratigraphy, coastline shifting, sedimentary characteristics, sedimentary dynamics, and correlation with anthropogenic global climate change. The results of these study areas are presented herein. The joint project also includes cooperative capacity building; exchanges of young scientists have been organized during the project period, and hands-on training in laboratory geochemical analysis, numerical modeling, and seismic data processing and interpretation have been provided by China and its Vietnamese geoscientist partners. Joint field excursions were organized to the upstream of the Yangtze and Red Rivers in Yunan Province, China, all the way downstream along the Vietnamese portion of the Red River. These joint studies have, over the past three years, improved understanding of the evolutionary history of these two major rivers and their mechanisms of source to sink. Joint project results of these two major deltas are not limited to the geosciences; the cooperativ

关键词： Yangtze River Delta Red River Delta Holocene sedimentary environment

A review on DFACS(II):Modeling and analysis of disturbances and noises

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Chinese Journal of Aeronautics 2024年第5期37卷 120-147页

作者： Chenglei YUE Bohan JIAO Zhaohui dang Xiaokui YUE Yonghe ZHANG Yuanqing XIA Li duan Qinglei HU Qifan LIU Pengcheng WANG Ming GUO Zhansheng duan Bing CUI Chu ZHANG Xiaodong SHAO School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 710699China School of Automation Beijing Institute of TechnologyBeijing 100081China Institute of Mechanics Chinese Academy of SciencesBeijing 710043China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Automation Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China

This paper presents Part II of a review on DFACS,which specifically focuses on the modeling and analysis of disturbances and noises in *** Part I,the system composition and dynamics model of the DFACS were *** this paper,we discuss the effects of disturbance forces and noises on the system,and summarize various analysis and modeling methods for these interferences,including the integral method,frequency domain analysis method,and magnitude evaluation *** analyzing the impact of disturbances and noises on the system,the paper also summarizes the system’s performance under slight ***,we highlight current research difficulties in the field of DFACS noise ***,this paper provides valuable insights into the modeling and analysis of disturbances and noises in DFACSs,and identifies key areas for future research.

关键词： Drag-free DFACS Disturbance Analysis Noise Analysis Frequency Domain Analysis Performance Evaluation

A review on DFACS(I):System design and dynamics modeling

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Chinese Journal of Aeronautics 2024年第5期37卷 92-119页

作者： Bohan JIAO Qifan LIU Zhaohui dang Xiaokui YUE Yonghe ZHANG Yuanqing XIA Li duan Qinglei HU Chenglei YUE Pengcheng WANG Ming GUO Zhansheng duan Bing CUI Chu ZHANG Xiaodong SHAO School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 710699China School of Automation Beijing Institute of TechnologyBeijing 100081China Institute of Mechanics Chinese Academy of SciencesBeijing 710043China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Automation Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China

The Drag-Free and Attitude Control System(DFACS)is a critical platform for various space missions,including high precision satellite navigation,geoscience and gravity field measurement,and space scientific *** paper presents a comprehensive review of over sixty years of research on the design and dynamics model of ***,we examine the open literature on DFACS and its applications in Drag-Free missions,providing readers with necessary background information on the ***,we analyze the system configurations and main characteristics of different DFACSs,paying particular attention to the coupling mechanism between the system configuration and dynamics ***,we summarize the dynamics modeling methods and main dynamics models of DFACS from multiple perspectives,including common fundamentals and specific ***,we identify current challenges and technological difficulties in the system design and dynamics modeling of DFACS,while suggesting potential avenues for future *** paper aims to provide readers with a comprehensive understanding of the state-of-the-art in DFACS research,as well as the future prospects and challenges in this field.

关键词： Drag-Free DFACS System Design Dynamics Modeling Control design

Same impact momentum causes different degrees of spinal cord injury

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Chinese Science Bulletin 2014年第32期59卷 4298-4303页

作者： Le Ji Xiaoqian dang Binshang Lan Qichun Song Dapeng duan Zhe Ji Yongtao Zhang Lisong Heng Department of Orthopedic Surgery The Second Affiliated Hospital School of Medicine Xi’an Jiaotong University Department of Orthopedic Surgery Shaanxi Provincial People’s Hospital Department of Orthopedic Surgery Xi’an Honghui Hospital

The weight-drop impact is widely used in making animal model of spinal cord injury(SCI).But there has not yet been an appropriate unit for the quantification of the *** this study,we compared the degrees of the spinal cord injury caused by weight-drop impact with the same momentum but different combinations of drop weight and drop height,in order to test whether‘‘momentum’’is capable of being the unit for the quantification of weightdrop *** adult rats were randomly allocated to three groups and were injured with 5 g–10 cm(group A),10 g–2.5 cm(group B)and 15 g–1.11 cm(group C)impacts with the same momentum to the spinal cord,***-field locomotor function was evaluated using the Basso–Beattie–Bresnahan(BBB)locomotor rating *** percentage of spared tissue area(STA)at the epicenter,and 500,1000 and 1500 lm from the epicenter was calculated using serial sections stained by hematoxylin and *** a result,the behavioral recovery(BBB scores)and the STA percentage were similar in group B and group ***,the BBB score in group A was significantly lower than that in groups B and C at the same time point post *** STA percentage was significantly less and the lesion/cavity length was significantlygreater in group A than in groups B and *** suggested that the 5 g–10 cm weight-drop impact,compared with the other two impacts with different weights and heights,caused a greater damage of the spinal cord when the momentum was the ***,these impacts with the same momentum but different weights and drop heights cause different degrees of spinal cord *** alone is inadequate to be the unit for the qualification of weightdrop impact and to be used to predict the extent of injury.

关键词：脊髓损伤运动功能 HE染色 STA 动物模型成年大鼠连续切片跌落高度

Combining Methods of Lyapunov for Exponential Stability of Linear Dynamic Systems on Time Scales

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Applied Mathematics 2014年第21期5卷 3452-3459页

作者： Nguyen Ngoc Huy dang dinh Chau Department of Mathematics Vietnam Water Resource University Hanoi Vietnam Department of Mathematics Vietnam National University of Science Hanoi Vietnam

Consider the linear dynamic equation on time scales (1) where , ,?is a rd-continuous function, T is a time scales. In this paper, we shall investigate some results for the exponential stability of the dynamic Equation... 详细信息

关键词： Time Scales Exponential Stability Linear Dynamic Equation