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Wagn Y.-P.,Xiangtan University | Wang X.-Y.,Xiangtan University | Kui X.-S.,Hunan Petrochemical Vocational Technology College | Wei Q.-L.,Xiangtan University | And 5 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2012

LiMn 2O 4 with high-performance for the application of lithium-ion batteries was successfully synthesized by a modified solid phase reaction route. First, the precursor Mn 3O 4 was prepared by a hydrolyzation-oxidation method using cheap MnSO 4 as Mn source. Then, the as-prepared precursor Mn 3O 4 and Li 2CO 3 were mixed homogeneously and calcined at 750°C for 20 h to obtain spinel LiMn 2O 4. The properties of samples were characterized by XRD and SEM, charge-discharge tests and cyclic voltammetry. The results show that the as-prepared LiMn 2O 4 has spine structure and exhibits uniform particle size distribution. The initial discharge capacities of the as-prepared LiMn 2O 4 are as high as 130.9 mA·h/g at 0.2C and 127.1 mA·h/g at 0.5C in the voltage range of 3.0-4.4 V at 25°C, especially, the discharge capacity at 30th cycle still keep to be 109.5 mA·h/g at 0.5C. Besides, the as-prepared LiMn 2O 4 presents good high temperature performance. Source


Rao W.,JiShou University | Rao W.,Hunan Petrochemical Vocational Technology College | Yin Y.,JiShou University | Long F.,JiShou University | And 2 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2015

A kind of magnetic molecularly imprinted polymers (mag-MIPs) was synthesized by heated polymerization technique using bisphenol A (BPA) as template, β-cyclodextrin (β-CD) and 4-vinylpyridine (4-VP) as the binary functional monomers. The mag-MIPs were characterized by means of transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). Adsorption experiments indicated that the mag-MIPs prepared with β-CD and 4-VP exhibited high selectivity toward BPA. The performance of the mag-MIPs used as magnetic solid-phase extraction (M-SPE) sorbent was evaluated, and the results showed that it could selectively extract BPA from water samples. The imprinted magnetic solid-phase extraction method has been applied for preconcentration and purification of BPA from water samples with the recoveries range of 90.51%-98.21%. ©, 2015, Higher Education Press. All right reserved. Source


Guo Y.,Hunan University | Guo Y.,Hunan Petrochemical Vocational Technology College | He D.,Hunan University | Xia S.,Hunan University | And 3 more authors.
Journal of Nanomaterials | Year: 2012

Polyaniline core decorated with TiO 2 (PANI- TiO 2) nanocomposite particles was successfully synthesized in ionic liquid/water (IL/water) microemulsion in the presence of anatase TiO 2 nanoparticles. The TiO 2 nanoparticles had been dispersed beforehand in OP-10 and n-butanol to weaken the strong particles agglomeration of TiO 2. The PANI- TiO 2 nanocomposites were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), and transmission electron microscope (TEM), and their electrochemical behavior was estimated by the electrochemical workstation. SEM micrographs showed that the nanocomposites exhibited spherical morphology with particle sizes about 70nm. The TEM result showed that the PANI- TiO 2 nanocomposites had a novel structure and that nanocrystalline TiO 2 deposited onto the surface of PANI, which was different from the reported structure of TiO 2-PANI nanocomposites. Both FTIR and UV-Vis spectra indicate that polyaniline and nano- TiO 2 particles are not simply blended or mixed up. A possible reaction mechanism for this nanocomposite preparation is suggested and analyzed. Copyright © 2012 Yanni Guo et al. Source


Hong B.,Xiangtan University | Chen Y.,Hunan Petrochemical Vocational Technology College | Li X.,Xiangtan University | Zhu Y.,Xiangtan University
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2015

To solve the problems of the instability seam-tracking signal and poor welding formability of the magnetic-control sensor in submerged arc welding, a Box-Behnken design (BBD) test method was proposed. The mathematical models of automatic submerged arc welding seam-tracking of magnetic-control sensor parameters such as excitation frequency, excitation current, magnetic pole height were built and response seam-tracking and weld width values were built based on the response surface method. By examining the fitting situation of the mathematical model on the test points, the sensor parameters were optimized according to the requirement of the quality of the seam-tracking signal and weld forming. Through the optimization of the sensor parameters, the quality of the seam-tracking signal and weld fusion width were predicted in submerged arc welding. The best combination between the seam-tracking signal and weld forming was realized, so as to the seam-tracking precision of the magnetic-control submerged arc welding and the welding quality were improved. ©, 2015, Hanjie Xuebao/Transactions of the China Welding Institution. All right reserved. Source


Peng L.,Hunan Agricultural University | Qin P.,Hunan Agricultural University | Zeng Q.,Hunan Agricultural University | Song H.,Hunan Petrochemical Vocational Technology College | And 4 more authors.
Sensors and Actuators, B: Chemical | Year: 2011

The ZnO nanorods (diameter of 40 nm and 100 nm) were modified with Ru(dcbpy)2(NCS)2 (RuN3), and their responses to formaldehyde were measured at room temperature. All the results showed that the responses to formaldehyde of modified ZnO were higher than that of bare ZnO; especially the responses of modified ZnO nanorods with diameter of 40 nm-5 ppm formaldehyde was about 200% higher than that of bare ZnO. The UV-vis absorption spectrum and transient photovoltage analysis showed that the high responses of modified ZnO mainly arose from the strong photocatalytic oxidizing effect induced by the increasing of the absorption and photo-generated electron-hole separation. Our results demonstrate that the modification of RuN3 is a promising approach on improving the formaldehyde responses of ZnO nanorods. © 2011 Published by Elsevier B.V. All rights reserved. Source

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