检索结果-南通市图书馆

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

引用

Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.H.Zhang H.Li Z.W.Yang X.Liu Q.f.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

来源：

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

A comparative study of semi-active control strategies for base isolated buildings

引用

Earthquake Engineering and Engineering Vibration 2015年第3期14卷 487-502页

作者： oliveira f. Morais P. Suleman A. National Laboratory for Civil Engineering (LNEC) Av. do Brasil 101 1700-066 Lisbon Portugal Scholarship HolderPh D CandidateMSc National Laboratory for Civil Engineering (LNEC) Av. do Brasil 101 1700-066 Lisbon Portugal Researcher Ph D University of Victoria Dep. Mechanical Engineering PO Box 1700 Stn CSC Victoria BC V8W 2Y2 Canada Professor Ph D PEng

A comparative analytical study of several control strategies for semi-active(SA) devices installed in baseisolated buildings aiming to reduce earthquake induced vibrations is *** force tracking schemes comprising a linear controller plus a 'clipped' algorithm and a nonlinear output feedback controller(NOfC) are considered to tackle this *** controllers include the integral controller(I),the linear quadratic regulator(LQR) and the model predictive controller(MPC).A single degree-of-freedom system subjected to input accelerograms representative of the Portuguese seismic actions are first used to validate and evaluate the feasibility of these *** obtained results show that structural systems using SA devices can in general outperform those equipped with passive devices for lower fundamental frequency structural systems,namely base-isolated *** effectiveness of the proposed strategies is also evaluated on a 10 storey base-isolated dual frame-wall *** force tracking scheme with an integral controller outperforms the other three as well as the original structure and the structure equipped with passive devices.

关键词： semi-active control integral controller linear qua

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimation of monthly global solar radiation over twelve major cities of Libya

引用

Energy and Built Environment 2024年第1期5卷 46-57页

作者： Alhassan Ali Teyabeen Najeya B.Elhatmi Akram A.Essnid f.Mohamed Libyan Center for Solar Energy Research and Studies TripoliLibya Libyan Authority of Scientific Research TripoliLibya

This study aims to estimate monthly averaged daily horizontal global solar *** climatological data collected at twelve major cities located across Libya’s map were used to establish 7 different empirical *** empirical coefficients of the models were calculated using the least square *** accuracy of the models was evaluated using different statistical criteria such as Taylor diagram,mean absolute percentage error,MAPE,and root mean square error,*** results indicated that the sunshine duration-based models are more accurate than air temperature-based models,and the best performance was obtained by the quadratic regression model for all twelve Libyan ***,this regression model can be used for the prediction of monthly mean horizontal global solar radiation at a specific site across Libya’s regions with minimum ***,the results of the global solar irradiance produced by this method can be used for designing solar systems applications.

关键词： Monthly global solar radiation Clearness index Empirical models Performance evaluation Taylor diagram Libya

来源：

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

RPLP0/TBP are the most stable reference genes for human dental pulp stem cells under osteogenic differentiation

引用

World Journal of Stem Cells 2024年第6期16卷 656-669页

作者： Daniel B ferreira Leticia M Gasparoni Cristiane f Bronzeri Katiucia B S Paiva Laboratory of Extracellular Matrix Biology and Cellular Interaction Department of AnatomyInstitute of Biomedical SciencesUniversity of São PauloSão Paulo 05508-000São PauloBrazil

BACKGROUND Validation of the reference gene(RG)stability during experimental analyses is essential for correct quantitative real-time polymerase chain reaction(RT-qPCR)data ***,in an unreliable way,several studies use genes involved in essential cellular functions[glyceraldehyde-3-phosphate dehydro-genase(GAPDH),18S rRNA,andβ-actin]without paying attention to whether they are suitable for such experimental conditions or the reason for choosing such ***,such studies use only one gene when Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines recom-mend two or more *** impacts the credibility of these studies and causes dis-tortions in the gene expression *** tissue engineering,the accuracy of gene expression drives the best experimental or therapeutical *** cultivated DPSCs under two conditions:Undifferentiated and osteogenic dif-ferentiation,both for 35 *** evaluated the gene expression of 10 candidates for RGs[ribosomal protein,large,P0(RPLP0),TATA-binding protein(TBP),GAPDH,actin beta(ACTB),tubulin(TUB),aminolevulinic acid synthase 1(ALAS1),tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein,zeta(YWHAZ),eukaryotic translational elongation factor 1 alpha(Ef1a),succinate dehydrogenase complex,subunit A,flavoprotein(SDHA),and beta-2-micro-globulin(B2M)]every 7 d(1,7,14,21,28,and 35 d)by *** data were analysed by the four main algorithms,ΔCt method,geNorm,Normfinder,and BestKeeper and ranked by the Reffinder *** subdivided the samples into eight *** All of the data sets from clonogenic and osteogenic samples were analysed using the Reffinder *** final ranking showed RPLP0/TBP as the two most stable RGs and TUB/B2M as the two least stable *** theΔCt method or Normfinder analysis showed TBP/RPLP0 as the two most stable ***,geNorm analysis showed RPLP0/Ef1αin the first *** algorithms’two least stab

关键词： Dental pulp stem cells Reference gene Housekeeping gene Endogenous gene Osteogenic differentiation Reffinder

来源：

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

Modelling dynamic pantograph loads with combined numerical analysis

引用

Railway Engineering Science 2024年第1期32卷 81-94页

作者： f.f.Jackson R.Mishra J.M.Rebelo J.Santos P.Antunes J.Pombo H.Magalhaes L.Wills M.Askill School of Computing and Engineering University of HuddersfieldHuddersfieldUK School of Computing and Engineering Institute of Railway ResearchUniversity of HuddersfieldHuddersfieldUK IDMEC Instituto Superior TecnicoUniversidade de LisboaLisbonPortugal ISEL Instituto Politecnico de LisboaLisbonPortugal Hitachi Rail Newton AycliffeUK Wabtec/Brecknell Willis ChardUK

Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric *** heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational *** research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact ***,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 *** an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph *** the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph *** results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.

关键词： Pantograph-catenary interaction Pantograph aerodynamics Computational fluid dynamics Pantograph loads Current collection performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

引用

Journal of Semiconductors 2024年第9期45卷 28-35页

作者： Leonarde N.Rodrigues Wesley f.Inoch Marcos L.f.Gomes Odilon D.D.Couto Jr. Bráulio S.Archanjo Sukarno O.ferreira Physics Department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

来源：

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

MicroRNAs in hepatocellular carcinoma treatment:Charting the path forward

引用

World Journal of Gastroenterology 2024年第11期30卷 1470-1474页

作者： Hong T Lin Antonio f Alvarez Castaneda Somashekar G Krishna Khalid Mumtaz Division of Gastroenterology Hepatology and NutritionDepartment of MedicineThe Ohio State University Wexner Medical CenterColumbusOH 43210United States

MicroRNAs(miRNAs)are recognized for their involvement in the regulation of gene expression and exhibit significant potential in both the prognostic assessment and treatment of hepatocellular carcinoma(HCC).HCC,like other tumors,seldom occurs in isolation;instead,it evolves within a microenvironment featuring oncogenic and tumor-suppressive *** combined with suitable delivery vehicles,miRNA technology provides the capability to directly engage with these elements,thereby hindering tumor formation and *** research in this domain holds the promise of enabling a more efficacious and multi-modal treatment approach for HCC in the near future.

关键词： Hepatocellular carcinoma Tumor microenvironment MicroRNA Mesenchymal stem cell Exosome

来源：

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

finite element analysis and experimental validation of polymer-metal contacts in block-on-ring configuration

引用

friction 2024年第3期12卷 554-568页

作者： K.Y.Eayal AWWAD Khosro fALLAHNEZHAD B.f.YOUSIf Ahmad MOSTAfA Omar ALAJARMEH A.SHALWAN Xuesen ZENG Mechanical Engineering Department Faculty of EngineeringTafila Technical UniversityTafila 66110Jordan Medical Device Research Institute College of Science and EngineeringFlinders UniversitySouth Australia 5042Australia Centre for future Materials University of Southern QueenslandToowoomba 4350Australia Department of Manufacturing Engineering Technology Public Authority for Applied Education and TrainingKuwait 13092Kuwait

The wear profile analysis,obtained by different tribometers,is essential to characterise the wear ***,most of the available methods did not take the stress distribution over the wear profile in consideration,which causes inaccurate *** this study,the wear profile of polymer–metal contact,obtained by block-on-ring configuration under dry sliding conditions,was analysed using finite element modelling(fEM)and experimental ***’s wear equation was integrated into a developed fORTRAN-UMESHMOTION code linked with Abaqus software.A varying wear coefficient(k)values covering both running-in and steady state regions,and a range of applied loads involving both mild and severe wear regions were measured and implemented in the *** fEM was in good agreement with the *** model reproduced the stress distribution profiles under variable testing conditions,while their values were affected by the sliding direction and maximum wear depth(hmax).The largest area of the wear profile,exposed to the average contact stresses,is defined as the normal *** the critical zones were characterized by high stress concentrations reaching up to 10 times of that at the normal *** wear profile was mapped to identify the critical zone where the stress concentration is the key point in this *** surface features were examined in different regions using scanning electron microscope(SEM).Ultimately,SEM analysis showed severer damage features in the critical zone than that in the normal zone as proven by ***,the literature data presented and considered the wear features the same at any point of the wear *** this study,the normal zone was determined at a stress value of about 0.5 MPa,whereas the critical zone was at about 5.5 *** wear behaviour of these two zones showed totally different features from one another.

关键词： polymer-to-metal contact block-on-ring wear profile wear model

来源：

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

The assessment of climatic,environmental,and socioeconomic aspects of the Brazilian Cerrado

引用

Ecological Processes 2023年第1期12卷 274-285页

作者： Washington Luiz félix Correia filho Joséfrancisco de oliveira-Júnior Dimas de Barros Santiago Hazem Ghassan Abdo Hussein Almohamad Ahmed Abdullah Al Dughairi Carlos Antonio da Silva Junior Postgraduate Program in Environmentrics(PPGAmb) Institute of MathematicsStatisticsand Physics(IMEF)Federal University of Rio Grande(FURG)Rio GrandeRio Grande do Sul 96203-900Brazil Institute of Atmospheric Sciences(ICAT) Federal University of Alagoas(UFAL)MaceióAlagoas 57072-260Brazil Postgraduate Program in Biosystems Engineering(PGEB) Federal Fluminense University(UFF)NiteróiRio de Janeiro 24220-900Brazil Postgraduate Program in Meteorology Unidade Acadêmica de Ciências Atmosféricas(UACA)Federal University of Campina Grande(UFCG)Campina GrandeParaíba 58429-140Brazil Geography Department Faculty of Arts and HumanitiesTartous UniversityTartousSyria Geography Department Faculty of Arts and HumanitiesDamascus UniversityDamascusSyria Geography Department Faculty of Arts and HumanitiesTishreen UniversityLat-takiaSyria Department of Geography College of Arabic Language and Social StudiesQassim UniversityBuraydah 51452Saudi Arabia Departamento de Geografia State University of Mato Grosso(UNEMAT)SinopMato Grosso 78555-000Brazil

Background The Cerrado is the most biodiverse savanna and maintains other *** of its significance,this paper evaluated the Brazilian Cerrado’s climatic,environmental,and socioeconomic aspects using remote sensing data and spatial statistics(correlation analysis and principal components analysis—PCA).following the measures of sample adequacy(MSA)and Kaiser–Meyer–Olkin(KMO)tests,seventeen variables were *** The MSA revealed that the dataset had a good quality(0.76),and nine variables were selected:elevation,evapotranspiration,active fires,Human Development Index(HDI),land use and land cover(LULC;shrubland and cropland/rainfed),rainfall(spring and autumn),and *** correlation matrix indicated a positive(negative)association between HDI and autumn rainfall(HDI and active fires)with a value of 0.77(-0.55).The PCA results determined which three principal components(PC)were adequate for extracting spatial patterns,accounting for 68.02%of the total variance with respective values of 38.59%,16.89%,and 12.5%.Due to economic development and agribusiness,Cerrado’s northern(central,western,and southern)areas had negative(positive)score HDI values,as shown in ***(rainfall—spring and fall)and environmental(cropland/rainfed and shrubland)aspects dominated the PC2,with negative scores in northern and western portions due to the transition zone between Amazon and Cerrado biomes caused by rainfall *** the other hand,environmental aspects(LULC-shrubland and elevation)influenced the PC3;areas with high altitudes(>500 m)received a higher *** Agricultural expansion substantially affected LULC,leading to deforestation-caused suppression of native vegetation.

关键词： Environment Agribusiness Active fire Human Development Index Land use and land cover

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sex differences in the risk of retinopathy of prematurity:a systematic review,frequentist and Bayesian meta‑analysis,and meta‑regression

引用

World Journal of Pediatrics 2024年第4期20卷 340-352页

作者： Tamara M.Hundscheid Silvia Gulden Mohamad f.Almutairi františek Bartoš Giacomo Cavallaro Eduardo Villamor Division of Neonatology Department of PediatricsMosaKids Children’s HospitalMaastricht University Medical Center(MUMC+)School for Oncology and Reproduction(GROW)Maastricht UniversityP.Debyelaan 25.P.O.Box 58006202 AZ MaastrichtThe Netherlands Neonatal Intensive Care Unit Sant’Anna HospitalComoItaly Department of Psychology University of Amsterdam1001 NK AmsterdamThe Netherlands Neonatal Intensive Care Unit Fondazione IRCCS Ca’Granda Ospedale Maggiore PoliclinicoMilanItaly

Background Retinopathy of prematurity(ROP)is generally considered to be more frequent in males than in ***,it is not known whether sex differences in ROP affect all degrees of the condition,are global and have changed as neonatology has *** aimed to conduct a systematic review and meta-analysis of studies addressing sex differences in the risk of developing *** PubMed/MEDLINE and Embase databases were *** frequentist,random-effects risk ratio(RR)and 95%confidence interval(CI)were *** model averaged(BMA)meta-analysis was used to calculate the Bayes factors(Bfs).The Bf10 is the ratio of the probability of the data under the alternative hypothesis(H1)over the probability of the data under the null hypothesis(H0).Results We included 205 studies(867,252 infants).frequentist meta-analysis showed a positive association between male sex and severe ROP(113 studies,RR=1.14,95%CI=1.07–1.22)but no association with any ROP(144 studies,RR=1.00,95%CI=0.96–1.03).BMA showed extreme evidence in favor of H1 for severe ROP(Bf10=71,174)and strong evidence in favor of H0 for any ROP(Bf10=0.05).The association between male sex and severe ROP remained stable over time and was present only in cohorts from countries with a high or high-middle sociodemographic *** Our study confirms the presence of a male disadvantage in severe ROP but not in less severe forms of the *** are variations in the sex differences in ROP,depending on geographical location and sociodemographic level of the countries.

关键词： Oxidative stress Retinopathy of prematurity Sex characteristics

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：