输电线路在覆冰荷载的作用下,容易引发倒塔、断线等安全事故,为了对输电线路覆冰进行提前预警,需要对线路上的覆冰厚度进行预测。本文基于数据驱动的方式,融合性能各异的覆冰预测模型,构建由初级层与次级层组成的输电线路覆冰厚度预测的...输电线路在覆冰荷载的作用下,容易引发倒塔、断线等安全事故,为了对输电线路覆冰进行提前预警,需要对线路上的覆冰厚度进行预测。本文基于数据驱动的方式,融合性能各异的覆冰预测模型,构建由初级层与次级层组成的输电线路覆冰厚度预测的Stacking集成模型。根据覆冰在线监测系统采集的气象数据与等值覆冰厚度,提取关联特征参数,训练Stacking覆冰预测模型的初级层(随机森林、最小二乘支持向量机、XGBoost、LSTM模型);通过初级层输出值对次级层的学习器进行训练,预测最终的覆冰厚度。结果表明,Stacking覆冰预测模型的MSE降低为0.5897 mm, R^(2)值达到0.9894。Stacking覆冰预测模型能够预测输电线路上的覆冰厚度,达到输电线路覆冰的安全预警作用,可以有效指导电网的抗冰工作。展开更多
Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work ...Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.e.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.Thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation.展开更多
文摘输电线路在覆冰荷载的作用下,容易引发倒塔、断线等安全事故,为了对输电线路覆冰进行提前预警,需要对线路上的覆冰厚度进行预测。本文基于数据驱动的方式,融合性能各异的覆冰预测模型,构建由初级层与次级层组成的输电线路覆冰厚度预测的Stacking集成模型。根据覆冰在线监测系统采集的气象数据与等值覆冰厚度,提取关联特征参数,训练Stacking覆冰预测模型的初级层(随机森林、最小二乘支持向量机、XGBoost、LSTM模型);通过初级层输出值对次级层的学习器进行训练,预测最终的覆冰厚度。结果表明,Stacking覆冰预测模型的MSE降低为0.5897 mm, R^(2)值达到0.9894。Stacking覆冰预测模型能够预测输电线路上的覆冰厚度,达到输电线路覆冰的安全预警作用,可以有效指导电网的抗冰工作。
基金financial support for this work provided by Eski sehir Technical University Scientific Research Projects Unit with Grant Number 20DRP059support provided by the Turkish Ministry of Science,Industry and Technology under the SANTEZ Project 0286.STZ.2013±2。
文摘Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.e.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.Thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation.
