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Creep damage characterization of UNS N10003 alloy based on a numerical simulation using the Norton creep law and Kachanov–Rabotnov creep damage model

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Nuclear Science and Techniques 2019年第4期30卷 114-122页

作者： xiao-Yan Wang xiao Wang xiao-chun zhang Shi-Feng Zhu Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The calculation of inelastic creep damage is important for the structural integrity evaluation of the elevated temperature structure in a thorium molten salt reactor(TMSR). However, a creep damage theory model and numerical simulation method have not been proposed for the key materials(UNS N10003 alloy) in the TMSR. In this study, creep damage characterization of UNS N10003 alloy is investigated using the Norton creep law and Kachanov–Rabotnov(K–R) creep damage model. First, the creep experimental data of the UNS N10003 alloy at 650 °C were adopted to fit the material constants of the two models. Then, the creep damage behavior of the UNS N10003 alloy was analyzed and discussed under uniaxial and multi-axial stress states. The results indicated that the K–R creep damage model is more suitable for the UNS N10003 alloy than the Norton model. Finally, the numerical simulation method was developed by a user-defined UMAT subroutine and subsequently verified through a finite element analysis(FEA). The FEA results were in agreement with the theoretical solutions. This study provides an effective method for the inelastic creep damage analysis of the elevated temperature structure in the TMSR.

关键词： Thorium molten salt reactor UNS N10003 alloy Creep damage Inelastic analysis Elevated temperature structure

Flood disaster monitoring based on Sentinel-1 data:A case study of Sihu Basin and Huaibei Plain,China

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Water Science and Engineering 2021年第2期14卷 87-96页

作者： Xu Yuan xiao-chun zhang Xiu-gui Wang Yu zhang State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Spatial Information Technology Application Research Department Changjiang River Scientific Research InstituteWuhan 430010China

Summer floods occur frequently in many regions of China,affecting economic development and social *** sensing is a new technique in disaster *** this study,the Sihu Basin in Hubei Province of China and the Huaibei Plain in Anhui Province of China were selected as the study *** of backscattering coefficients in the decision tree method were calculated with the histogram analysis method,and flood disaster monitoring in the two study areas was conducted with the threshold method using Sentinel-1 satellite *** satellite-based flood disaster monitoring,the flooded maps and the areas of expanded water bodies and flooded crops were *** satellite-based monitoring maps were derived by comparing the expanded area of images during a flood disaster with that before the *** difference in spatiotemporal distribution of flood disasters in these two regions was *** results showed that flood disasters in the Sihu Basin occurred frequently in June and July,and flood disasters in the Huaibei Plain mostly occurred in August,with a high interannual *** disasters in the Sihu Basin were usually widespread,and the affected area was between Changhu and Honghu *** Huaibei Plain was affected by scattered *** annual mean percentages of flooded crop area were 14.91%and 3.74% in the Sihu Basin and Huaibei Plain,*** accuracies of the extracted flooded area in the Sihu Basin in 2016 and 2017 were 96.20% and 95.19%,respectively.

关键词： Flood disaster monitoring Sentinel-1 radar image Remote sensing Threshold method Sihu Basin Huaibei Plain

Simplified SEBAL method for estimating vast areal evapotranspiration with MODIS data

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Water Science and Engineering 2011年第1期4卷 24-35页

作者： xiao-chun zhang Jing-wei WU Hua-yi WU Yong LI State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 P. R. China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430070 R R. China School of Earth Sciences and Engineering Hohai University Nanjing 210098 R R. China

The SEBAL （surface energy balance algorithm for land） model provides an efficient tool for estimating the spatial distribution of evapotranspiration, and performs a simple adjustment procedure to calculate sensible heat flux using the wind speed data set from only one weather station. This paper proposes a simplified method to modify the traditional SEBAL model for calculating the 24-hour evapotranspiration （ ETduly ） in the Haihe Basin with data from 34 weather stations. We interpolated the wind speeds using the inverse distance weighting method to establish a wind field and then used it to calculate the friction velocity directly. This process also simplifies the iterative computation process of sensible heat flux. To validate the feasibility of this simplified method, we compared the results with those obtained with an appropriate but more complex method proposed by Tasumi, which separates a vast area into several sub-areas based on the weather conditions, and runs the SEBAL model separately in each sub-area. The results show good agreement between the evapotranspiration generated by the two methods, with a coefficient of determination （r2） of 0.966, which indicates the feasibility of estimating evapotranspiration over a large region with the simplified method.

关键词： evapotranspiration SEBAL model MOD1S, remote sensing sensible heat flux Haihe Basin

Numerical simulation of stress behavior of dowel–brick structures in TMSR

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Nuclear Science and Techniques 2020年第5期31卷 77-87页

作者： Hui-Qing Fan Chao-Chao Huang xiao Wang D.K.L.Tsang xiao-chun zhang xiao-Yan Wang Shi-Feng Zhu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China

As essential elements of the graphite reflector in thorium-based molten salt reactor,dowel–brick structures are used to withstand complex working loads in the reactor core and their failure may lead to serious damage of the graphite reactor *** is crucial to investigate the stress behavior of dowel–brick structures for safe operation of the graphite *** this study,three groups of finite element analyses and a strain test were carried out to investigate how the geometric parameters of the dowels affect the stress behavior of the dowel–brick *** numerical results indicate that the stress behavior of a dowel–brick structure is significantly affected by the diameter,length,and aspect ratio of the *** maximum stress in the lower and upper bricks decreases with an increase in the dowel *** location of maximum stress on both lower and upper bricks shifts from the root of the socket to the edge of that socket beside the contact region,as the length of the dowel *** shift of the maximum stress location occurs earlier for the upper bricks than for the lower *** results of strain tests show good agreement with those of numerical analyses.

关键词： Dowel–brick structure FEA Stress behavior Strain test

Small balloon strategy associated with low pacemaker implantation rate after self-expanding transcatheter valve implantation

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World Journal of Emergency Medicine 2021年第1期12卷 48-53页

作者： Yuan zhang Wen-zhi Pan Li-hua Guan xiao-chun zhang Sha-sha Chen Li-fan Yang Lei zhang Ming-fei Li Dan-dan Chen Da-xin Zhou Jun-bo Ge Department of Cardiology Shanghai Institute of Cardiovascular DiseaseZhongshan HospitalFudan UniversityShanghai 200032China

BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty(BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valveimplantation (TAVI).METHODS: This was a retrospective analysis using data from our local TAVI database. SmallBAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as aballoon size >18 mm. The primary endpoint was the incidence of new ***: Of 99 consecutive TAVI patients, five patients were excluded due to pre-existingpermanent pacemaker. Patients in the small BAV group (n=57) had a signifi cantly lower PPMI ratecompared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aorticvalve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3%vs. 8.1%, P=0.480);likewise, the mean aortic gradient post-procedure did not differ significantly(11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Devicesuccess rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV(P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradientby echo in the basement (P=0.021) were independent predictors of ***: The small BAV strategy is associated with a low rate of permanentpacemaker implantation after transcatheter self-expanding valve implantation in this single-centerobservational study.

关键词： Transcatheter aortic valve implantation Balloon aortic valvuloplasty Balloon size Permanent pacemaker implantation

Calculation of response of Chinese hamster cells to ions based on track structure theory

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Nuclear Science and Techniques 1997年第4期 51-53页

作者： Liu xiao Wei, zhang chun Xiang ( Department of Physics, Zhongshan University, Guangzhou 510275 )

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关键词： Chinese hamster cells Track theory Ions Dose response

Long-term outcome of patients with atrial myxoma after surgical intervention: analysis of 403 cases

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Journal of Geriatric Cardiology 2019年第4期16卷 338-343页

作者： Chen-Xi JIANG Jian-Gang WANG Rui-Dong QI Wei WANG Li-Jian GAO Jing-Hua ZHAO chun-xiao zhang Meng-Chen ZHOU Xin TU Mei-Sheng SHANG Yan YAO Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina Department of Cardiovascular Surgery Beijing Anzhen HospitalCapital Medical UniversityBeijingChina Center for Coronary Heart Disease Department of CardiologyCardiovascular Institute & Fuwai HospitalCAMS & PUMCNational Center for Heart DiseaseBeijingChina College of Life Science and Technology Huazhong University of Science and TechnologyWuhanChina

Objective To assess long-term survival and late cardiovascular events in patients with atrial myxoma after surgical intervention. Methods Retrospective analysis of 403 patients undergoing resection of atrial myxoma from January 2002 to December 2016 was conducted with a median follow-up period of 4.5 (range: 0.5?15) years. Results The cross-clamp time and cardiopulmonary bypass times were 41.1 ± 21.4 and 65.2 ± 27.3 min,respectively. A diagnosis of myxoma was histopathologically confirmed in all cases. The early in-hospital mortality rate was 0.7%(n = 3). During the follow-up period,tumor recurrence occurred in six patients and cerebral infarction in nine. There were 48 (11.9%) patients with late onset atrial fibrillation (AF). By multivariate analysis,age (HR = 1.05,95% CI: 1.02–1.09,P < 0.001),left atrial diameter (HR = 1.23,95% CI: 1.08–1.36,P = 0.012),and mitral valve surgery (HR = 1.17,95% CI: 1.05–1.29,P = 0.027) were independent predictors of late onset AF. Twenty-one (5.2%) patients died during the follow-up period. Advanced age (HR = 1.07,95% CI: 1.04–1.10,P = 0.003) and multiple surgical procedures (HR = 1.18,95% CI: 1.06–1.29,P = 0.012) were significantly associated with overall mortality. Conclusions Atrial myxoma can be resected with good long-term survival. Late onset AF is common after surgery in patients with atrial myxoma. Advanced age,left atrial diameter,and mitral valve surgery were independent predictors of outcomes.

关键词： Atrial fibrillation Atrial myxoma Embolism Survival

Updating the diagnostic criteria of COVID-19 “suspected case” and “confirmed case” is necessary

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Military Medical Research 2020年第4期7卷 507-509页

作者： Yun-Yun Wang Ying-Hui Jin Xue-Qun Ren Yi-Rong Li xiao-chun zhang Xian-Tao Zeng Xing-Huan Wang the Zhongnan Hospital of Wuhan University Novel Coronavirus Management and Research Team Center for Evidence-Based and Translational Medicine Zhongnan Hospital of Wuhan UniversityWuhan 430071HubeiChina Institute of Evidence-Based Medicine and Knowledge Translation Henan UniversityKaifeng 475000HenanChina Department of Clinical Laboratory Zhongnan Hospital of Wuhan UniversityWuhan 430071HubeiChina Leishenshan Hospital of Wuhan Wuhan 430200HubeiChina Department of Radiology Zhongnan Hospital of Wuhan UniversityWuhan 430071HubeiChina 不详

On 6 February 2020,our team had published a rapid advice guideline for diagnosis and treatment of 2019 novel coronavirus(2019-nCoV)infection,and this guideline provided our experience and make well reference for fighting against this pandemic ***,the coronavirus disease 2019(COVID-19)is a new disease,our awareness and knowledge are gradually increasing based on the ongoing research findings and clinical practice experience;hence,the strategies of diagnosis and treatment are also continually *** this letter,we answered one comment on our guideline and provided the newest diagnostic criteria of"suspected case"and"confirmed case"according to the latest Diagnosis and Treatment Guidelines for COVID-19(seventh version)that issued by the National Health Committee of the People’s Republic of China.

关键词： COVID-19 SARS-CoV-2 2019-nCoV Guideline Prevention Diagnosis Treatment Novel coronavirus

Protective effect of resveratrol against cyclophosphamide-induced testis injury in mice

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Protective effect of resveratrol against cyclophosphamide-in...