A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary...A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.展开更多
Developing a stable insulation material stands as a crucial challenge for high-voltage direct current(HVDC)cable insulation.This work proposes an alloying strategy to significantly enhance the breakdown strength and h...Developing a stable insulation material stands as a crucial challenge for high-voltage direct current(HVDC)cable insulation.This work proposes an alloying strategy to significantly enhance the breakdown strength and high-temperature resistivity of cross-linked polyethylene(XLPE).The strategy involves blending low-density polyethylene(LDPE)with polystyrene(PS),resulting in a polymeric alloy.Confirmation of PS alloying within XLPE is supported by observed shifts in polyethylene miller indices(110)and(200)planes.The dicumyl peroxide used as a crosslinking agent demonstrates an ideal 1.41% enhancement in LDPE-PS crosslinking.The integration of aromatic ethers in the cross-linked network enhances temperature stability.Alloying PS at 220℃ in XLPE leads to improved inter-molecular interactions and increased interfacial area,creating a sea-island morphology that resolves voids and limits defect or crack propagation by form-ing additional trapping sites.The enhanced breakdown strength and reduced conductivity of XLPE-PS are attributed to increased deep trapping sites and reduced carrier mobility resulting from alloying.The reduced conductivity at 70℃ and 90℃ demonstrates stability under electric fields.Remarkable breakdown strength improvements of 27.5%and 23.6% are observed at 30℃ and 50℃.The proposed alloying strategy suggests replacing XLPE with advanced XLPE-PS,offering promising prospects for HVDC insulation.展开更多
The recently published article“A stable zeolite with atomically ordered and interconnected mesopore channels”by P.Lu,et al.[1]will likely spur increased interest in zeolites as many barriers have now been opened by ...The recently published article“A stable zeolite with atomically ordered and interconnected mesopore channels”by P.Lu,et al.[1]will likely spur increased interest in zeolites as many barriers have now been opened by this seminal work.In a nutshell,the ordered micro-/meso-porous barrier of zeolites is broken as the synthesis of a stable material with native interconnected micro-and meso-porosities opens the door to more similar accomplishments and potentially significant applications.展开更多
基金Funded by the Open Project Program of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(No.KLIFMD201606)the Open Fund of National Innovation Platform(No.2017YJ163)+1 种基金the National Natural Science Foundation of China(Nos.51502220,51521001,and 51672197)the Open Foundation of Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics(Wuhan University of Technology)(No.TAM201802)。
文摘A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.
基金State Grid Corporation of China,Grant/Award Number:5500-202258104A-1-1-ZN。
文摘Developing a stable insulation material stands as a crucial challenge for high-voltage direct current(HVDC)cable insulation.This work proposes an alloying strategy to significantly enhance the breakdown strength and high-temperature resistivity of cross-linked polyethylene(XLPE).The strategy involves blending low-density polyethylene(LDPE)with polystyrene(PS),resulting in a polymeric alloy.Confirmation of PS alloying within XLPE is supported by observed shifts in polyethylene miller indices(110)and(200)planes.The dicumyl peroxide used as a crosslinking agent demonstrates an ideal 1.41% enhancement in LDPE-PS crosslinking.The integration of aromatic ethers in the cross-linked network enhances temperature stability.Alloying PS at 220℃ in XLPE leads to improved inter-molecular interactions and increased interfacial area,creating a sea-island morphology that resolves voids and limits defect or crack propagation by form-ing additional trapping sites.The enhanced breakdown strength and reduced conductivity of XLPE-PS are attributed to increased deep trapping sites and reduced carrier mobility resulting from alloying.The reduced conductivity at 70℃ and 90℃ demonstrates stability under electric fields.Remarkable breakdown strength improvements of 27.5%and 23.6% are observed at 30℃ and 50℃.The proposed alloying strategy suggests replacing XLPE with advanced XLPE-PS,offering promising prospects for HVDC insulation.
文摘The recently published article“A stable zeolite with atomically ordered and interconnected mesopore channels”by P.Lu,et al.[1]will likely spur increased interest in zeolites as many barriers have now been opened by this seminal work.In a nutshell,the ordered micro-/meso-porous barrier of zeolites is broken as the synthesis of a stable material with native interconnected micro-and meso-porosities opens the door to more similar accomplishments and potentially significant applications.
