Barium ferrite micro/nano fibers were successfully prepared via the electrostatic spinning by using dimethyl formamide（DMF） as the solvent, and poly vinyl pyrrolidone（PVP） as the spinning auxiliaries. Effects of s...Barium ferrite micro/nano fibers were successfully prepared via the electrostatic spinning by using dimethyl formamide（DMF） as the solvent, and poly vinyl pyrrolidone（PVP） as the spinning auxiliaries. Effects of strontium substitution on the structure, morphology, and magnetic properties were investigated by scanning electron microscope（SEM）, X-ray diffraction analysis（XRD）, and vibration sample magnetometer（VSM）. XRD patterns of the samples confirm that pure barium ferrite fibers form, and the Sr substitution makes the main peaks（110）,（107）, and（114） move to right slightly. Also, the FE-SEM images show that the Sr substituted fibers can keep complete fibrous morphology. Moreover, the VSM results demonstrate that the saturation magnetization can reach 56.7 emu/g when the fibers are calcined at 800℃.展开更多
The magnetic properties of spinel ferrites Cu_（1-x）Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_...The magnetic properties of spinel ferrites Cu_（1-x）Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_（AA）, J_（BB） and J_（AB） are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained.展开更多
The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic pro...The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic properties with the annealing temperature and time is essentially the same. The magnetic properties of the Fe-based nanocrystalline alloys for the partial substitution of V for Nb reduce, and the crystallizing treatment temperature of the alloys increases. The optimum properties of Fe74Cu1Nb3Si13B9 nanocrystalline alloys crystallized at 550℃x60 min are μ0=9.2xl0^4, μm=54.8xl0^4, Hc=1.14 A/m and Bs=1.26 T. The best properties for Fe74Cu1Nb3Si13B9 alloys annealed at 560℃x60 min are μ0=8.79x10^4, μm=50.18xl0^4, Hc=1.26 A/m and Bs=1.24 T.展开更多
3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH...3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.展开更多
基金Funded by the Qilu Program in Shandong University and the Natural Science Foundation of Shandong Province(ZR2014EMM001)
文摘Barium ferrite micro/nano fibers were successfully prepared via the electrostatic spinning by using dimethyl formamide（DMF） as the solvent, and poly vinyl pyrrolidone（PVP） as the spinning auxiliaries. Effects of strontium substitution on the structure, morphology, and magnetic properties were investigated by scanning electron microscope（SEM）, X-ray diffraction analysis（XRD）, and vibration sample magnetometer（VSM）. XRD patterns of the samples confirm that pure barium ferrite fibers form, and the Sr substitution makes the main peaks（110）,（107）, and（114） move to right slightly. Also, the FE-SEM images show that the Sr substituted fibers can keep complete fibrous morphology. Moreover, the VSM results demonstrate that the saturation magnetization can reach 56.7 emu/g when the fibers are calcined at 800℃.
文摘The magnetic properties of spinel ferrites Cu_（1-x）Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_（AA）, J_（BB） and J_（AB） are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained.
文摘The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic properties with the annealing temperature and time is essentially the same. The magnetic properties of the Fe-based nanocrystalline alloys for the partial substitution of V for Nb reduce, and the crystallizing treatment temperature of the alloys increases. The optimum properties of Fe74Cu1Nb3Si13B9 nanocrystalline alloys crystallized at 550℃x60 min are μ0=9.2xl0^4, μm=54.8xl0^4, Hc=1.14 A/m and Bs=1.26 T. The best properties for Fe74Cu1Nb3Si13B9 alloys annealed at 560℃x60 min are μ0=8.79x10^4, μm=50.18xl0^4, Hc=1.26 A/m and Bs=1.24 T.
基金Director of the project supported by National Natural Science foundation of China.
文摘3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.
