A precise U-Pb baddeleyite age of 1999±2 Ma has been obtained for the NNW trending Lac Shpogan dyke swarm of the James Bay area of the eastern Superior craton.Previously the age of the swarm was only
The North Atlantic Craton(NAC)represents one of approximately three dozen preserved Archean cratonic fragments now dispersed globally,but its affinity to formerly neighboring supercontinent cratonic blocks
Pioneering U-Pb isotopic studies by a small group of workers in the mid-late 1980s demonstrated the feasibility of using rare accessory mineral chronometers in mafic(gabbroic)intrusive rocks.These examples showed that...Pioneering U-Pb isotopic studies by a small group of workers in the mid-late 1980s demonstrated the feasibility of using rare accessory mineral chronometers in mafic(gabbroic)intrusive rocks.These examples showed that mafic layered intrusions and diabase/dolerite dyke swarms alike crystallized high-temperature展开更多
Several generations of mafic dyke swarms of different ages and geochemical characteristics cut Precambrian rocks of the southern part of the Siberian craton(Irkutsk Promontory).Each generation of dykes is related to a
Since its inception,Systems Engineering(SE)has developed as a distinctive discipline,and there has been significant progress in this field in the past two decades.Compared to other engineering disciplines,SE is not af...Since its inception,Systems Engineering(SE)has developed as a distinctive discipline,and there has been significant progress in this field in the past two decades.Compared to other engineering disciplines,SE is not affirmed by a set of underlying fundamental propositions,instead it has emerged as a set of best practices to deal with intricacies stemming from the stochastic nature of engineering complex systems and addressing their problems.Since the existing methodologies and paradigms(dominant patterns of thought and concepts)of SE are very diverse and somewhat fragmented.This appears to create some confusion regarding the design,deployment,operation,and application of SE.The purpose of this paper is 1)to delineate the development of SE from 1926-2017 based on insights derived from a histogram analysis,2)to discuss the different paradigms and school of thoughts related to SE,3)to derive a set of fundamental attributes of SE using advanced coding techniques and analysis,and 4)to present a newly developed instrument that could assess the performance of systems engineers.More than Two hundred and fifty different sources have been reviewed in this research in order to demonstrate the development trajectory of the SE discipline based on the frequency of publication.展开更多
文摘A precise U-Pb baddeleyite age of 1999±2 Ma has been obtained for the NNW trending Lac Shpogan dyke swarm of the James Bay area of the eastern Superior craton.Previously the age of the swarm was only
文摘The North Atlantic Craton(NAC)represents one of approximately three dozen preserved Archean cratonic fragments now dispersed globally,but its affinity to formerly neighboring supercontinent cratonic blocks
文摘Pioneering U-Pb isotopic studies by a small group of workers in the mid-late 1980s demonstrated the feasibility of using rare accessory mineral chronometers in mafic(gabbroic)intrusive rocks.These examples showed that mafic layered intrusions and diabase/dolerite dyke swarms alike crystallized high-temperature
文摘Several generations of mafic dyke swarms of different ages and geochemical characteristics cut Precambrian rocks of the southern part of the Siberian craton(Irkutsk Promontory).Each generation of dykes is related to a
基金We would like to personally thank anonymous reviewers for raising such questions that have transformed this manuscript into a muchimproved paper.
文摘Since its inception,Systems Engineering(SE)has developed as a distinctive discipline,and there has been significant progress in this field in the past two decades.Compared to other engineering disciplines,SE is not affirmed by a set of underlying fundamental propositions,instead it has emerged as a set of best practices to deal with intricacies stemming from the stochastic nature of engineering complex systems and addressing their problems.Since the existing methodologies and paradigms(dominant patterns of thought and concepts)of SE are very diverse and somewhat fragmented.This appears to create some confusion regarding the design,deployment,operation,and application of SE.The purpose of this paper is 1)to delineate the development of SE from 1926-2017 based on insights derived from a histogram analysis,2)to discuss the different paradigms and school of thoughts related to SE,3)to derive a set of fundamental attributes of SE using advanced coding techniques and analysis,and 4)to present a newly developed instrument that could assess the performance of systems engineers.More than Two hundred and fifty different sources have been reviewed in this research in order to demonstrate the development trajectory of the SE discipline based on the frequency of publication.
