检索结果-南通市图书馆

fragility crossover mediated by covalent-like electronic interactions in metallic liquids

在线全文

学校读者我要写书评

暂无评论

Materials Futures

Materials Futures 2024年第2期3卷 117-130页

作者： Hui-Ru Zhang Liang Gao Yu-Hao Ye Jia-Xin Zhang Tao Zhang Qing-Zhou Bu Qun Yang Zeng-Wei Zhu Shuai Wei Hai-Bin Yu Wuhan National High Magnetic Field Center and School of Physics Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China Department of Chemistry Aarhus University8000 AarhusDenmark iMAT Centre for Integrated Materials Research Aarhus University8000 AarhusDenmark

fragility is one of the central concepts in glass and liquid sciences,as it characterizes the extent of deviation of viscosity from Arrhenius behavior and is linked to a range of glass ***,the intervention of crystallization often prevents the assessment of fragility in poor glass-formers,such as supercooled metallic *** experimental data on their compositional dependence are scarce,let alone fundamentally *** this work,we use fast scanning calorimetry to overcome this obstacle and systematically study the fragility in a ternary La–Ni–Al system,over previously inaccessible composition *** observe fragility dropped in a small range with the Al alloying,indicating an alloying-induced fragility *** use x-ray photoelectron spectroscopy,resistance measurements,electronic structure calculations,and DFT-based deep-learning atomic simulations to investigate the cause of this fragility *** results show that the fragility crossover can be fundamentally ascribed to the electronic covalency associated with the unique Al–Al *** findings provide insight into the origin of fragility in metallic liquids from an electronic structure perspective and pave a new way for the design of metallic glasses.

关键词： metallic glass fragility fast scanning calorimetry density functional theory deep learning potential

Seismic performance assessment of high CFRDs based on fragility analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2019年第4期62卷 635-648页

作者： PANG Rui XU Bin ZOU DeGao KONG XianJing School of Hydraulic Engineering Faculty of Infrastructure Engineering Dalian University of Technology State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology

Due to a large number of high concrete face rockfill dams(CFRDs) being constructed, the seismic safety is crucially important and seismic performance assessment must be performed for such dams. fragility analysis is a method of great vitality for seismic performance assessment; it can intuitively forecast the structural effects of different ground motion intensities and provide an effective path for structure safety assessment. However, this method is rarely applied in the field of high earth dam risk *** paper introduces fragility analysis into the field of high CFRD safety assessment and establishes seismic performance assessment methods. PGA, Sa(T1, 5%), PGV and PGD are exploited as the earthquake intensity measure(IMs). Relative settlement ratio of dam crest, cumulative sliding displacement of dam slope stability and a new face-slab destroying index(based on DCR and COD) are regarded as the dam damage measures(DMs). The dividing standards of failure grades of high CFRDs are suggested based on each DM. fragility function is estimated according to incremental dynamic analysis(IDA) and multiple stripes analysis(MSA) methods respectively from a large number of finite element calculations of a certain CFRD, and seismic fragility curves are determined for each DM. Finally, this study analyzes the failure probabilities of the dam under different earthquake intensities and can provide references and bases for the seismic performance design and safety risk assessment of high CFRDs.

关键词： high CFRDs seismic performance fragility analysis failure grades IDA MSA

Seismic fragility of flexible pipeline connections in a base isolated medical building

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2019年第4期18卷 903-916页

作者： Shang Qingxue Wang Tao Li Jichao Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration

Flexible pipelines are often used to connect hard pipes from a foundation to a superstructure to accommodate large deformation in the base isolation layer during an earthquake. Although Chinese seismic design guidelines suggest several confi gurations, they are diff erent from the designs that have been proven in practice, e.g., Japanese styles, and extensive experimental investigation into their seismic performance is required. Three types of seals, rubber-, metal- and asbestinebased, were tested quasi-statically with infi lled pressurized water at 2.5 MPa. The asbestine-based seal leaked at a smaller deformation than the other two types of seals. Based on the test results, three damage states were defi ned and the deformation capacity was estimated. To evaluate their performance, a three-dimensional model of a base-isolated medical building was developed using OpenSees, with the fl exible pipelines simulated by a mechanical model calibrated from the experimental data. A probabilistic seismic demand model and the fragility function of the fl exible pipelines were then developed to evaluate the seismic performance.

关键词： fl exible pipeline connections isolated building quasi-static tests fragility curve probabilistic seismic demand model

Time-variant fragility analysis of the bridge system considering time-varying dependence among typical component seismic demands

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2019年第2期18卷 363-377页

作者： Song Shuai Qian Yongjiu Liu Jing Xie Xiaorui Wu Gang Department of Civil Engineering Taiyuan University of Technology Department of Bridge Engineering Southwest Jiaotong University Department of Environmental Science Baylor University Southwest Municipal Engineering Design and Research Institute of China School of Civil Engineering and Architecture East China Jiaotong University

This paper presents a copula technique to develop time-variant seismic fragility curves for corroded bridges at the system level and considers the realistic time-varying dependence among component seismic demands. Based on material deterioration mechanisms and incremental dynamic analysis, the time-evolving seismic demands of components were obtained in the form of marginal probability distributions. The time-varying dependences among bridge components were then captured with the best fitting copula function, which was selected from the commonly used copula classes by the empirical distribution based analysis method. The system time-variant fragility curves at different damage states were developed and the effects of time-varying dependences among components on the bridge system fragility were investigated. The results indicate the time-varying dependence among components significantly affects the time-variant fragility of the bridge system. The copula technique captures the nonlinear dependence among component seismic demands accurately and easily by separating the marginal distributions and the dependence among them.

关键词： system fragility chloride corrosion time-varying dependence copula function probabilistic seismic demand

Effects of Microalloying on Glass Forming Ability and Thermodynamic fragility of Cu-Pr-Based Amorphous Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2007年第5期25卷 615-618页

作者：李雪莲边秀房郭晶赵岩武玉琴孙保安 Key Laboratory of Liquid Structure and Heredity of Materials Ministry of Education Shandong University

The effects of microalloying of Ti and B on the glass formation of Cu60Pr30Ni10Al10-2xTixBx（x = 0, 0.05% （atom fraction）） amorphous alloys was investigated using differential scanning calorimetry （DSC） and X-ray diffraction （XRD）. XRD analysis showed that mieroalloying with 0.05% Ti and 0.05% B improved the glass forming ability （GFA）. The smaller difference in the Gibbs free energy between the liquid and crystalline states at the glass transition temperature （△G1-X（Tg）） and the smaller thermodynamic fragility index （△Sf/Tm, where ASf is the entropy of fusion, and Tm is the melting temperature） after mieroalloying correlated with the higher GFA.

关键词： mieroalloying glass forming ability fragility difference in Gibbs free energy rare earths

Correlation between superheated liquid fragility and potential energy landscape in Gd-and Pr-based glass-forming alloys

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 387-393页

作者： GUO Jing BIAN XiuFang LI XueLian WANG CaiDong Key Laboratory of Liquid Structure and Heredity of Materials Ministry of EducationShandong UniversityJinan 250061China

The kinetic viscosities of superheated liquids on the Gd-based bulk glass-forming alloys are measured by an oscillating viscometer in a high vacuum atmosphere. According to the viscosity data,the parameters of superheated liquid fragility,M,are calculated. Based on the values of M in Gd-and Pr-based (cited from the lit-erature) glass-forming alloys,we find that there is a linear correlation between M and the absolute value of mixing enthalpy,|ΔHmix|,in an alloy system with the same base element,and the larger M,the smaller |ΔHmix|. The alloy with larger M exhibits the larger height of energy barriers separating the minima on the potential energy landscape.

关键词： glass-forming alloy superheated liquid fragility potential energy landscape

Seismic fragility Analysis of Long-Span Bridge System with Durability Degradation

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2019年第10期121卷 177-214页

作者： Yan Liang Jialei Yan Zhanqi Cheng Huai Chen Ruimin Mao College of Civil Engineering Zhengzhou UniversityZhengzhouChina

An offshore long-span continuous rigid-frame bridge is taken as an example to study the effect of degradation of bond-slip behavior on the seismic performance of bridges in an offshore environment during a service *** the basis of a numerical simulation analysis using the OpenSeeS platform,the influence of durability degradation of concrete carbonization,steel corrosion,and degradation of bond-slip performance is considered collectively using incremental dynamic analysis method to examine the time-varying seismic fragility of the offshore *** show that when bond slip is considered,the exceedance probability of the bridge components and the system increases significantly,and the durability degradation caused by concrete carbonization and chloride ion erosion in the whole life cycle increases the seismic response of the bridge *** results of the proposed time-varying seismic fragility analysis indicate that,considering the degradation of bond-slip behavior of reinforced concrete after the durability degradation of materials,the exceedance probability of the pier,bearing,abutment,and system increases with the extension of service period and the increase in seismic strength under earthquake *** addition,with the extension of service time,the effect of bond slip on the seismic fragility of components and system gradually decreases.

关键词： Bridge durability degradation bond slip seismic fragility

Unusual presentation of congenital radioulnar synostosis with osteoporosis,fragility fracture and nonunion:A case report and review of literature

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第8期8卷 1538-1546页

作者： Zhan-Yu Yang Jiang-Dong Ni Ze Long Le-Tian Kuang Shi-Bin Tao Department of Orthopedics The Second Xiangya HospitalCentral South UniversityChangsha 410000Hunan ProvinceChina

BACKGROUND Congenital radioulnar synostosis(CRUS)is a rare deformity of the upper *** is characterized by loss of rotation of the involved forearm and functional limitations in daily *** studies on CRUS with osteoporosis have been reported to date,and osteoporosis is usually recognized as an important dimension of genetic disorder in *** discuss the possible relationship among this disorder,osteoporosis and fracture nonunion,investigate the strict surgical indications and recommended *** SUMMARY A 14-year-old male patient with bilateral CRUS with osteoporosis,fragility fracture and nonunion of fractures in ulna and radius presented our institution for further treatment,complaining of limitation in *** bone mineral density of the hip and lumbar spine was 0.687 g/cm2 and 0.705 g/cm2,respectively,and the Z-score for both was-2.1,which revealed osteoporosis and a high risk of *** serum bone turnover markers indicated an imbalance of bone *** for ulna fracture with autogenous bone grafting and a postoperative physiotherapy program were adopted rather than the separation of pathological *** examination,observational posture assessment and limb function scale were evaluated before and 1 year after *** 1 year,the fracture nonunion had almost recovered,forearm movement function on the fracture side was restored,and function on the healthy side was significantly improved compared with that before *** Surgical indications for CRUS vary from person to *** should not be the first choice of treatment,and physiotherapy is not inferior to surgical treatment.

关键词： Congenital radioulnar synostosis Surgical indication Osteoporosis fragility fracture Nonunion Case report

fragility of disconnect switch subjected to random earthquake ground motions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai University(English Edition) 2011年第3期15卷 180-184页

作者：吕宝龙陈玲俐叶志明 Department of Civil Engineering Shanghai University

A fragility calculation scheme is estabtished in this paper for porcelain-type equipments subjected to random earthquake ground motions. All steps of the method are illustrated by the seismic damage analysis of GW4-110 disconnect switch. The model of the equipment is built applying the finite element method with flexible joints, and the seismic response of the equipment is analyzed using elastic time history method. On the base, according to the strength damage index and Monte-Carlo Method, the seismic damage ratios are counted and the seismic fragility curves are presented. Then the seismic damage of GW4-110 disconnect switch can be predicted.

关键词： disconnect switch fragility random earthquake ground motion strength damage index