简介:WehavecarefullyreadDr.Yuandhiscolleagues'~1reviewonthemechanismofhamstringmusclestraininjuryinsprinting.Thereisnodoubtthattheyhavedonealotworkinthisfield.Theirviewsarebasedon3piecesofevidence.First,observationsfrominsituanimalmodelssuggestthatmusclestraininjuriesarehighlyassociatedwitheccentriccontractions.Second,themagnitudeofmusclestrain,ratherthantheforce,is
简介:判断液压设备故障要求具备相应的专业知识,通晓单体设备的工作方式及其在整个控制系统中的功能,尤其是电气和液压线路图。根据维修西马克挤压机液压系统故障的工作经验,以最具代表性的18MN西马克挤压机为研究对象,重点分析18MN西马克挤压机挤压力故障产生的原因及其处理方法。
简介:摘要随着建筑行业日益兴盛,建筑施工越来越规范化、合理化,新型材料、技术的应用在质量、安全、节能、工期等方面的优化显得尤为重要。铝合金模板,以其各方面巨大的优越性逐渐取代传统木质模板,成为建筑工程中不可缺少的施工工艺。
简介:TheeffectofMnsubstitutionforpartialFeinRFe11Tionstructureandmagneticpropertiesofcompoundswasresearched.RFe7Mn4Tisamples(R=Y,Tb,Dy,Ho,Er)werepreparedbymeansofvacuumarc-meltingandsubsequentvacuumannealing.ThestructureandmagneticpropertiesofRFe7Mn4TicompoundswereinvestigatedbyX-raypowderdiffractionandmagneticmeasurements.Thefollowingconclusionswereobtained:alltheRFe7Mn4TicompoundscrystallizeintheThMn12-typestructure.Thelatticeconstantsandtheunit-cellvolumechangedwiththeincreaseofatomicnumberforR=Y,Th,Dy,Ho,andEr.ThecompensationcharactersappearfortheDyFe7Mn4TiandHoFe7Mn4Ticompounds,andthecompensationtemperatureswereabout123Kand90K,respectively.TheCurietemperature,thesaturationmagnetization,andsaturationmomentofRFe7Mn4Ticompoundsweregiven.