故障预测及健康管理(prognostics and health management,PHM)对于增强系统的可靠性以及提高系统的可维护性具有重要意义。随着电力电子装置在各领域的广泛应用,研究电力电子装置的PHM技术势在必行。由于具有非侵入性的特点,基于混杂模...故障预测及健康管理(prognostics and health management,PHM)对于增强系统的可靠性以及提高系统的可维护性具有重要意义。随着电力电子装置在各领域的广泛应用,研究电力电子装置的PHM技术势在必行。由于具有非侵入性的特点,基于混杂模型的LC参数辨识方法是一种先进的PHM技术实现方式。然而,由于忽略了开关瞬态的二极管电流的突变,现有的混杂模型并不适用于Boost型电路。为了解决这一问题,对现有模型进行了修正,并提出一种基于小波去噪以及最小二乘算法的参数辨识方法。通过Matlab/Simulink仿真分析和实验验证,结果表明,该方法的参数辨识精度可达95%以上,验证了该修正模型的有效性。展开更多
Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which th...Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.展开更多
Fabric-based composites with superior mechanical properties and excellent perceptive function are highly desirable.However,it remains a huge challenge to attain structure-function integration,especially for hybrid fab...Fabric-based composites with superior mechanical properties and excellent perceptive function are highly desirable.However,it remains a huge challenge to attain structure-function integration,especially for hybrid fabric composites.Herein,a skin-inspired interface modification strategy is proposed toward this target by constructing a hybrid smart fabric system consisting of two types of smart fabrics:carbon nanotube(CNT)/MXene-modified aramid fabrics and zinc oxide nanorod(ZnO NR)-modified carbon fabrics.Based on that,flexible piezoelectric pressure sensors with skin-like hierarchical perception interfaces are fabricated,which demonstrate superb sensitivity of 2.39 V·kPa^(-1)and are capable of various wearable monitoring tasks.Besides,the interface-modified hybrid fabric reinforced plastics can also be fabricated,which are proven to possess 13.6%higher tensile strength,10.1%elastic modulus.More impressively,their average energy absorption can be improved by 111.9%,accompanied with inherent damage alert capability.This offers a paradigm to fabricate structure-function integrated hybrid smart fabric composites for the smart clothing and intelligent aerial vehicles.展开更多
文摘故障预测及健康管理(prognostics and health management,PHM)对于增强系统的可靠性以及提高系统的可维护性具有重要意义。随着电力电子装置在各领域的广泛应用,研究电力电子装置的PHM技术势在必行。由于具有非侵入性的特点,基于混杂模型的LC参数辨识方法是一种先进的PHM技术实现方式。然而,由于忽略了开关瞬态的二极管电流的突变,现有的混杂模型并不适用于Boost型电路。为了解决这一问题,对现有模型进行了修正,并提出一种基于小波去噪以及最小二乘算法的参数辨识方法。通过Matlab/Simulink仿真分析和实验验证,结果表明,该方法的参数辨识精度可达95%以上,验证了该修正模型的有效性。
基金Supported by Hunan Provincial Natural Science Foundation of China (Grant No. 06JJ20036)
文摘Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.
基金supported by the National Natural Science Foundation of China(Nos.52205298,52375280 and 51775022)Project funded by China Postdoctoral Science Foundation(Nos.2022M710302 and 2022TQ0023)the Fundamental Research Funds for the Central Universities.
文摘Fabric-based composites with superior mechanical properties and excellent perceptive function are highly desirable.However,it remains a huge challenge to attain structure-function integration,especially for hybrid fabric composites.Herein,a skin-inspired interface modification strategy is proposed toward this target by constructing a hybrid smart fabric system consisting of two types of smart fabrics:carbon nanotube(CNT)/MXene-modified aramid fabrics and zinc oxide nanorod(ZnO NR)-modified carbon fabrics.Based on that,flexible piezoelectric pressure sensors with skin-like hierarchical perception interfaces are fabricated,which demonstrate superb sensitivity of 2.39 V·kPa^(-1)and are capable of various wearable monitoring tasks.Besides,the interface-modified hybrid fabric reinforced plastics can also be fabricated,which are proven to possess 13.6%higher tensile strength,10.1%elastic modulus.More impressively,their average energy absorption can be improved by 111.9%,accompanied with inherent damage alert capability.This offers a paradigm to fabricate structure-function integrated hybrid smart fabric composites for the smart clothing and intelligent aerial vehicles.
