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
The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a che...The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a chemically and photochemically stable material in which a synergistic effect between the metal-organic cluster and the polyoxometalate allows marked enhancement of the photochemical activity of the single ionic components toward the photooxidation of dyes.展开更多
NaGdF_(4) is a well-known up-conversion material with potential applications in lasers and biolabels and used to be known as a thermally stable material bearing harsh natural conditions.In this work,a TEM electron bea...NaGdF_(4) is a well-known up-conversion material with potential applications in lasers and biolabels and used to be known as a thermally stable material bearing harsh natural conditions.In this work,a TEM electron beam was found to be able to manipulate the morphology of cubic-NaGdF_(4),changing it from solid nanoparticles to porous materials with nano-sized vacancies by electron beam irradiation.Electron beams also induce a structure change from cubic-NaGdF_(4) to GdF_(3).By controlling the current density of the TEM electron beam,the in situ epitaxial growth behavior of GdF_(3)(020)was observed at the NaGdF_(4)(111)interface.Structural correlations between two compounds were discussed to understand the epitaxial growth with a large lattice mismatch.These findings suggest a TEM electron beam can be used not only as an imaging tool,but also as an alternative paradigm for manipulating matter.展开更多
Exploitation of stable proton conducting materials with high stability and excellent conductivity is becom-ing more important but challenging.Herein,two novel porous transition metal-organic frameworks(MOFs),formulate...Exploitation of stable proton conducting materials with high stability and excellent conductivity is becom-ing more important but challenging.Herein,two novel porous transition metal-organic frameworks(MOFs),formulated as[Zn(btzip)(H_(2)O)]·H_(2)O(LCUH-107)and[Ni(btzip)(H_(2)btzip)]·4H_(2)O(LCUH-108),are successfully synthesized.LCUH-107 and LCUH-108 exhibit excellent thermal and chemical stabilities.LCUH-108 has a suitable pore size(8.36Å×5.74Å)to load trifluoroacetic acid(TFA,5.72Å×5.65Å×5.06Å),which is larger than that of LCUH-107(3.50Å×2.04Å).Therefore,TFA molecules can be loaded into the pores of LCUH-108 while they were only loaded onto the surface of LCUH-107.Both TFA/LCUH-107(2.95×10^(-2)S cm^(−1))and TFA@LCUH-108(2.05×10^(-1)S cm^(−1))exhibit excellent proton con-duction at 80℃and 100%relative humidity(RH);in particular,the proton conductivity value of TFA@LCUH-108 can be as high as 10-1 S cm^(−1),which might be due to the fact that TFA molecules can be confined into their suitable pores and finally form strong continuous and stable hydrogen-bonding networks.The TFA molecules loaded into the suitable pores of LCUH-108 play a key role in improving greatly the proton conductivity of LCUH-108,while TFA molecules loaded onto the surface of LCUH-107 can only slightly improve the proton conductivity of LCUH-107,which can be confirmed by various con-trast tests and simulated calculations.This work gives a novel strategy to design efficient artificial crystal-line catalysts for proton conduction.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financial support from the Basque Government(IT1291-19)from the University of the Basque Country(predoctoral fellowships for J.P.C.and M.P.I.:PIF17/51 and PIF18/175)+1 种基金from the Spanish Ministry of Science and Innovation(PID2019-108028GB-C21)Technical and human support provided by SGIker(UPV/EHU,MICINN,GV/EJ,and ESF)is also acknowledged.
文摘The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a chemically and photochemically stable material in which a synergistic effect between the metal-organic cluster and the polyoxometalate allows marked enhancement of the photochemical activity of the single ionic components toward the photooxidation of dyes.
基金supported by the National Natural Science Foundation of China(Grant No.21271139 and 21201012).
文摘NaGdF_(4) is a well-known up-conversion material with potential applications in lasers and biolabels and used to be known as a thermally stable material bearing harsh natural conditions.In this work,a TEM electron beam was found to be able to manipulate the morphology of cubic-NaGdF_(4),changing it from solid nanoparticles to porous materials with nano-sized vacancies by electron beam irradiation.Electron beams also induce a structure change from cubic-NaGdF_(4) to GdF_(3).By controlling the current density of the TEM electron beam,the in situ epitaxial growth behavior of GdF_(3)(020)was observed at the NaGdF_(4)(111)interface.Structural correlations between two compounds were discussed to understand the epitaxial growth with a large lattice mismatch.These findings suggest a TEM electron beam can be used not only as an imaging tool,but also as an alternative paradigm for manipulating matter.
基金supported by the National Natural Science Foundation of China(21401095,21801107,22178157)the Natural Science Foundation of Shandong Province(ZR2022MB010,ZR2019MB068,ZR2021QB123)+5 种基金the Project of Shandong Province Higher Educational Science and Technology Program(KJ2018BZC043 and J18KA113)the Liaocheng University Start-up Fund for Doctoral Scientific Research(318050104 and 318052017)the Scientific Research Fund of Liaocheng University(318011913)the Youth Innovation Team of Shandong Colleges and Universities(2019KJC027 and 2020KJC012)the Open Fund of Liaocheng University(2020CESNCTKL02)the Shandong Students Innovation and Entrepreneurship Training Program(319260210).
文摘Exploitation of stable proton conducting materials with high stability and excellent conductivity is becom-ing more important but challenging.Herein,two novel porous transition metal-organic frameworks(MOFs),formulated as[Zn(btzip)(H_(2)O)]·H_(2)O(LCUH-107)and[Ni(btzip)(H_(2)btzip)]·4H_(2)O(LCUH-108),are successfully synthesized.LCUH-107 and LCUH-108 exhibit excellent thermal and chemical stabilities.LCUH-108 has a suitable pore size(8.36Å×5.74Å)to load trifluoroacetic acid(TFA,5.72Å×5.65Å×5.06Å),which is larger than that of LCUH-107(3.50Å×2.04Å).Therefore,TFA molecules can be loaded into the pores of LCUH-108 while they were only loaded onto the surface of LCUH-107.Both TFA/LCUH-107(2.95×10^(-2)S cm^(−1))and TFA@LCUH-108(2.05×10^(-1)S cm^(−1))exhibit excellent proton con-duction at 80℃and 100%relative humidity(RH);in particular,the proton conductivity value of TFA@LCUH-108 can be as high as 10-1 S cm^(−1),which might be due to the fact that TFA molecules can be confined into their suitable pores and finally form strong continuous and stable hydrogen-bonding networks.The TFA molecules loaded into the suitable pores of LCUH-108 play a key role in improving greatly the proton conductivity of LCUH-108,while TFA molecules loaded onto the surface of LCUH-107 can only slightly improve the proton conductivity of LCUH-107,which can be confirmed by various con-trast tests and simulated calculations.This work gives a novel strategy to design efficient artificial crystal-line catalysts for proton conduction.
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.
