Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spi...Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism.展开更多
A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.T...A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.The results of experiment show that the mixtures of CTAC and PAE had higher conductivities than PAE;The mixtures of OEMD-20 had lower conductivities than PAE.展开更多
Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepa...Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepared by the sol-gel method with sintering at 1000℃. The powder is characterized by X-ray diffraction （XRD） and scanning electron micrograph （SEM）. The apatite can be obtained at relatively low temperature as compared to the conventional solid-state reaction method. The measurements of conductivity of a series of doped samples La9.33-2x/3MxSi6O26 （M=Ca, Mg, Sr） indicate that the type of dopant and the amount have a significant effect on the conductivity. The greatest decrease in conductivity is observed for Mg doping, following the Ca and the Sr doped apatites. The effect is ultimately attributed to the amount of oxygen interstitials, which is affected by the crystal lattice distortion arising from cation vacancies.展开更多
The cation—conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single—cation conduction over a wide range of plasticizer composition. The plasticiz...The cation—conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single—cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.展开更多
Two kinds of lithium methoxy oligo(oxyethylene) sulfate LiSAEO_8 and LiSAEO_(12) were synthesized. The blend complexes of the salts with P(MEO_(16)—AM) show high cationic conductivity, the transference numbers of lit...Two kinds of lithium methoxy oligo(oxyethylene) sulfate LiSAEO_8 and LiSAEO_(12) were synthesized. The blend complexes of the salts with P(MEO_(16)—AM) show high cationic conductivity, the transference numbers of lithium ion(t_+)in [P(MEO_(16)—AM)/LiSAEO_8] and [-P(MEO_(16)—AM)/LiSAEO_(12)] are 0.93 and 0.98 at 50℃, and their ambient conductivities are 1.4×10^(-5)/cm and 7.7×10^(-6)S/cm respectively.展开更多
The electrical conductivities (ECs) of suspensions containing 25 and 30 gkg^(-1) solids prepared from the electrodialyzed clay fraction (< 2μm in diameter) of latosol,yellow-brown soil, and black soil, dispersed i...The electrical conductivities (ECs) of suspensions containing 25 and 30 gkg^(-1) solids prepared from the electrodialyzed clay fraction (< 2μm in diameter) of latosol,yellow-brown soil, and black soil, dispersed in various nitrate solutions having concentrations of 1X 10^(-4)/z mol L^(-1), where z is the valence, and in distilled water, were measured at fieldstrengths ranging from 14 kV cm^(-1) to 210 kV cm^(-1). On the basis of analyses of the chargedensity and exchangeable ion composition on the surfaces of soil particles in the suspensions, andof the characters of the EC-field strength curves of the various suspensions, it was inferred thatthe increment of EC (ΔEC) and/or relative electrical conductivity (REC) can indicate the bondingstrength between cations and soil particles. The bonding strengths of various cations with the soilsdiminished in the order: K^+ > Zn^(2+) > Mg^(2+) = Ca^(2+) > Na^+ for latosol, Ca^(2+) > Zn^(2+) >Mg^(2+) = K^+ > Na^+ for yellow-brown soil, and Zn^(2+) ≥ Ca^(2+) ≥ Mg^(2+) > K^+ > Na^+ for blacksoil.展开更多
Two oxetane-derived monomers, 3-（2-cyano-ethoxy）methyl- and 3-（methoxy-（triethylenoxy））methyl-3＇- methyloxetane （COX and MTOX）, were prepared from 3-hydroxymethyl-3＇-methyloxetane. Their homo- and copolymeri...Two oxetane-derived monomers, 3-（2-cyano-ethoxy）methyl- and 3-（methoxy-（triethylenoxy））methyl-3＇- methyloxetane （COX and MTOX）, were prepared from 3-hydroxymethyl-3＇-methyloxetane. Their homo- and copolymerization in solution were carried out by the cationic ring-opening polymerization with BF3 · Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end （ACE） and activated monomer （AM） mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using ^1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10^-3.58 S/cm at 30℃ and 10^-2.73 S/cm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.展开更多
The synthesis of silicate oxyapatitesLa10-x（SiO4）6O3-1.5x（x=0. 0.17, 0.33, 0.50 and 0.67） via a sol-gel method at 800 ℃ was reported. The apatite phases were characterized by X-ray diffraction （XRD） and conduct...The synthesis of silicate oxyapatitesLa10-x（SiO4）6O3-1.5x（x=0. 0.17, 0.33, 0.50 and 0.67） via a sol-gel method at 800 ℃ was reported. The apatite phases were characterized by X-ray diffraction （XRD） and conducting properties were studied by electrochemical impedance spectroscopy （EIS）. It is found that the conductivities are influenced by the amount of cation vacancies and interstitial oxygen. The conductivity of La9.33 （SiO4）6O2 with more cation vacancies is higher than that of La9.5 （SiO4）6O2.25. The conductivity of La10 （SiO4）6O3 with more interstitial oxygen is 7.98 ×10^-3 S·cm^-1, which is about 5 times higher than that of La9.33（SiO4）6O2 at 700℃. The electrical conductivity is almost independent of the oxygen partial pressure from 105 to 1 Pa, which suggests that the oxyapatites exhibit almost pure O^2- ion conduction over a wide range of oxygen partial pressure.展开更多
This contribution is not only intended to provide a fresh review for researches on static electrification, but also contains a sub- stantial amount of new material with a view of closing some gaps in the present state...This contribution is not only intended to provide a fresh review for researches on static electrification, but also contains a sub- stantial amount of new material with a view of closing some gaps in the present state of knowledge of oil streaming electrification. In this paper, the Electrostatic Charging Tendency (ECT) of fresh (unaged) and aged transformer oils were investigated in a spinning disk system. Static electrification measurement at different aging degrees was carried out under laboratory controlled conditions. Changes in static elec- trification were compared to some classical aging indexes (conductivity, dissipation factor, water content, resistivity, etc.). Fast, inexpensive and reliable laboratory testing procedures developed by American Society for Testing Materials (D 6802 and D 6181) were also used to monitor decay products as trace impurities. The obtained results show that static electrification currents increase with temperature, fluid mo- tion velocity, surface properties and the aging byproducts of the oil. The polarity, the amplitude and the time constant of the electrification currents are also affected. The results show that static electrification has relationship with thermal aging and is sensitive to turbidimetric and spectrophotometric measurements.展开更多
文摘Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism.
文摘A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.The results of experiment show that the mixtures of CTAC and PAE had higher conductivities than PAE;The mixtures of OEMD-20 had lower conductivities than PAE.
基金Supported by the Natural Science Foundation of Guangdong PrOvince （06025657） and Guangdong Provincial Green Chemicals.
文摘Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepared by the sol-gel method with sintering at 1000℃. The powder is characterized by X-ray diffraction （XRD） and scanning electron micrograph （SEM）. The apatite can be obtained at relatively low temperature as compared to the conventional solid-state reaction method. The measurements of conductivity of a series of doped samples La9.33-2x/3MxSi6O26 （M=Ca, Mg, Sr） indicate that the type of dopant and the amount have a significant effect on the conductivity. The greatest decrease in conductivity is observed for Mg doping, following the Ca and the Sr doped apatites. The effect is ultimately attributed to the amount of oxygen interstitials, which is affected by the crystal lattice distortion arising from cation vacancies.
文摘The cation—conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single—cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.
文摘Two kinds of lithium methoxy oligo(oxyethylene) sulfate LiSAEO_8 and LiSAEO_(12) were synthesized. The blend complexes of the salts with P(MEO_(16)—AM) show high cationic conductivity, the transference numbers of lithium ion(t_+)in [P(MEO_(16)—AM)/LiSAEO_8] and [-P(MEO_(16)—AM)/LiSAEO_(12)] are 0.93 and 0.98 at 50℃, and their ambient conductivities are 1.4×10^(-5)/cm and 7.7×10^(-6)S/cm respectively.
基金Project(Nos.49771046 and 49831005)supported by the National Natural Science Foundation of China and the Center for International Cooperation,Ministry of Foreign Affairs,State of Israel.
文摘The electrical conductivities (ECs) of suspensions containing 25 and 30 gkg^(-1) solids prepared from the electrodialyzed clay fraction (< 2μm in diameter) of latosol,yellow-brown soil, and black soil, dispersed in various nitrate solutions having concentrations of 1X 10^(-4)/z mol L^(-1), where z is the valence, and in distilled water, were measured at fieldstrengths ranging from 14 kV cm^(-1) to 210 kV cm^(-1). On the basis of analyses of the chargedensity and exchangeable ion composition on the surfaces of soil particles in the suspensions, andof the characters of the EC-field strength curves of the various suspensions, it was inferred thatthe increment of EC (ΔEC) and/or relative electrical conductivity (REC) can indicate the bondingstrength between cations and soil particles. The bonding strengths of various cations with the soilsdiminished in the order: K^+ > Zn^(2+) > Mg^(2+) = Ca^(2+) > Na^+ for latosol, Ca^(2+) > Zn^(2+) >Mg^(2+) = K^+ > Na^+ for yellow-brown soil, and Zn^(2+) ≥ Ca^(2+) ≥ Mg^(2+) > K^+ > Na^+ for blacksoil.
基金This research work was funded by National Key Projects on Basic Research and Development (The "973" Project, No. 2002CB211800).
文摘Two oxetane-derived monomers, 3-（2-cyano-ethoxy）methyl- and 3-（methoxy-（triethylenoxy））methyl-3＇- methyloxetane （COX and MTOX）, were prepared from 3-hydroxymethyl-3＇-methyloxetane. Their homo- and copolymerization in solution were carried out by the cationic ring-opening polymerization with BF3 · Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end （ACE） and activated monomer （AM） mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using ^1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10^-3.58 S/cm at 30℃ and 10^-2.73 S/cm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.
文摘The synthesis of silicate oxyapatitesLa10-x（SiO4）6O3-1.5x（x=0. 0.17, 0.33, 0.50 and 0.67） via a sol-gel method at 800 ℃ was reported. The apatite phases were characterized by X-ray diffraction （XRD） and conducting properties were studied by electrochemical impedance spectroscopy （EIS）. It is found that the conductivities are influenced by the amount of cation vacancies and interstitial oxygen. The conductivity of La9.33 （SiO4）6O2 with more cation vacancies is higher than that of La9.5 （SiO4）6O2.25. The conductivity of La10 （SiO4）6O3 with more interstitial oxygen is 7.98 ×10^-3 S·cm^-1, which is about 5 times higher than that of La9.33（SiO4）6O2 at 700℃. The electrical conductivity is almost independent of the oxygen partial pressure from 105 to 1 Pa, which suggests that the oxyapatites exhibit almost pure O^2- ion conduction over a wide range of oxygen partial pressure.
文摘This contribution is not only intended to provide a fresh review for researches on static electrification, but also contains a sub- stantial amount of new material with a view of closing some gaps in the present state of knowledge of oil streaming electrification. In this paper, the Electrostatic Charging Tendency (ECT) of fresh (unaged) and aged transformer oils were investigated in a spinning disk system. Static electrification measurement at different aging degrees was carried out under laboratory controlled conditions. Changes in static elec- trification were compared to some classical aging indexes (conductivity, dissipation factor, water content, resistivity, etc.). Fast, inexpensive and reliable laboratory testing procedures developed by American Society for Testing Materials (D 6802 and D 6181) were also used to monitor decay products as trace impurities. The obtained results show that static electrification currents increase with temperature, fluid mo- tion velocity, surface properties and the aging byproducts of the oil. The polarity, the amplitude and the time constant of the electrification currents are also affected. The results show that static electrification has relationship with thermal aging and is sensitive to turbidimetric and spectrophotometric measurements.
