Chains are typically used for tension load transfer. They are very flexible and allow easy length adjustment by hooking at the links. Steel is the traditional material for chains. Recently, synthetic link chains made ...Chains are typically used for tension load transfer. They are very flexible and allow easy length adjustment by hooking at the links. Steel is the traditional material for chains. Recently, synthetic link chains made from ultra-strong polyethylene fibers, branded as Dyneema®, are commercially available. These chains offer a highly improved strength to weight ratio. So far, one type of such chains is available, and it has a Working Load Limit of 100 kN. 50 of such chains, containing 6 links were tested to fracture. The strength of each chain and the location of the failed link were documented during testing for later interpretation. Weibull statistics was applied in order to extrapolate towards the allowable load for very low failure risks (high reliability). Two approaches were used. One extrapolation was based on all results;the other was applied after recognition that the end links failed under a slight negative influence by the connection to the testing equipment. Thus, in fact two populations are mixed, the chains with failing end links and the chains with failing central links. So considering the population without the failing end links is more representative for pure chain behavior without clamping effects. The results from this latter consideration showed a higher Weibull exponent, thus a more realistic extrapolation behavior. Both methods indicate that the reliability at the working load limit of 100 kN is very good.展开更多
目的了解重症监护病房(intensive care unit,ICU)护士职业成长的现状,探讨基本心理需求、工作动机在ICU护士结构授权与职业成长间的作用路径和中介效应,为促进ICU护士职业成长、稳定护理队伍提供参考。方法便利选取ICU的227名护士,使用...目的了解重症监护病房(intensive care unit,ICU)护士职业成长的现状,探讨基本心理需求、工作动机在ICU护士结构授权与职业成长间的作用路径和中介效应,为促进ICU护士职业成长、稳定护理队伍提供参考。方法便利选取ICU的227名护士,使用一般资料调查问卷、工作条件效能量表、基本心理需求量表、工作动机量表、职业成长量表调查研究对象一般情况、结构授权、基本心理需求、工作动机及职业成长。采用Spearman相关分析研究基本心理需求、工作动机及结构授权与ICU护士职业成长的相关性。运用AMOS 24.0软件构建结构方程模型并进行路径分析,采用Bootstrap方法进行中介效应检验。结果ICU护士结构授权总分为63.0(53.0,75.0)分,基本心理需求总分为95.0(88.0,108.0)分,工作动机总分为30.0(26.0,32.0)分,职业成长总分为50.0(45.0,59.0)分。职业成长总分与基本心理需求总分、工作动机总分、结构授权总分呈正相关(P<0.05)。结构授权对ICU护士职业成长的总间接效应值0.456,占总效应的60.64%,其中工作动机特定中介效应值为0.301,占总效应的40.03%,基本心理需求和工作动机的链式中介效应值为0.155,占总效应的20.61%。结论ICU护士职业成长处于中上水平,基本心理需求与工作动机在结构授权与职业成长间发挥链式中介效应,护理管理者应重视结构授权,满足ICU护士基本心理需求,激发其工作动机,进而促进其职业成长。展开更多
文摘Chains are typically used for tension load transfer. They are very flexible and allow easy length adjustment by hooking at the links. Steel is the traditional material for chains. Recently, synthetic link chains made from ultra-strong polyethylene fibers, branded as Dyneema®, are commercially available. These chains offer a highly improved strength to weight ratio. So far, one type of such chains is available, and it has a Working Load Limit of 100 kN. 50 of such chains, containing 6 links were tested to fracture. The strength of each chain and the location of the failed link were documented during testing for later interpretation. Weibull statistics was applied in order to extrapolate towards the allowable load for very low failure risks (high reliability). Two approaches were used. One extrapolation was based on all results;the other was applied after recognition that the end links failed under a slight negative influence by the connection to the testing equipment. Thus, in fact two populations are mixed, the chains with failing end links and the chains with failing central links. So considering the population without the failing end links is more representative for pure chain behavior without clamping effects. The results from this latter consideration showed a higher Weibull exponent, thus a more realistic extrapolation behavior. Both methods indicate that the reliability at the working load limit of 100 kN is very good.
文摘目的了解重症监护病房(intensive care unit,ICU)护士职业成长的现状,探讨基本心理需求、工作动机在ICU护士结构授权与职业成长间的作用路径和中介效应,为促进ICU护士职业成长、稳定护理队伍提供参考。方法便利选取ICU的227名护士,使用一般资料调查问卷、工作条件效能量表、基本心理需求量表、工作动机量表、职业成长量表调查研究对象一般情况、结构授权、基本心理需求、工作动机及职业成长。采用Spearman相关分析研究基本心理需求、工作动机及结构授权与ICU护士职业成长的相关性。运用AMOS 24.0软件构建结构方程模型并进行路径分析,采用Bootstrap方法进行中介效应检验。结果ICU护士结构授权总分为63.0(53.0,75.0)分,基本心理需求总分为95.0(88.0,108.0)分,工作动机总分为30.0(26.0,32.0)分,职业成长总分为50.0(45.0,59.0)分。职业成长总分与基本心理需求总分、工作动机总分、结构授权总分呈正相关(P<0.05)。结构授权对ICU护士职业成长的总间接效应值0.456,占总效应的60.64%,其中工作动机特定中介效应值为0.301,占总效应的40.03%,基本心理需求和工作动机的链式中介效应值为0.155,占总效应的20.61%。结论ICU护士职业成长处于中上水平,基本心理需求与工作动机在结构授权与职业成长间发挥链式中介效应,护理管理者应重视结构授权,满足ICU护士基本心理需求,激发其工作动机,进而促进其职业成长。
