合成了锌-铝-铈三元类水滑石(Zn Al Ce-CO3-LDHs),确定最佳合成条件为:p H=8、Ce/Al=0.05,反应温度及陈化温度分布为40、100℃。将Zn Al Ce-CO3-LDHs改性后测试其作为PVC稳定剂的热稳定效果,结果表明:Zn Al CeCO3-LDHs是一种高效的PVC...合成了锌-铝-铈三元类水滑石(Zn Al Ce-CO3-LDHs),确定最佳合成条件为:p H=8、Ce/Al=0.05,反应温度及陈化温度分布为40、100℃。将Zn Al Ce-CO3-LDHs改性后测试其作为PVC稳定剂的热稳定效果,结果表明:Zn Al CeCO3-LDHs是一种高效的PVC热稳定剂,改性后稳定效果更佳,在钙锌稳定剂中掺入少许Zn Al Ce-CO3-LDHs,能够大幅提高钙锌稳定剂稳定效果。展开更多
Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coat...Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coatings were investigated through energy-dispersive X-ray spectroscopy （EDS）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, electron probe micro-analysis （EPMA） and scanning electron microscopy （SEM） together with hydrogen volumetric and electrochemical tests. The results indicate that both coatings predominately contain crystalline hopeite （Zn3（PO4）2·4H2O）, Mg3（PO4）2 and Ca3（PO4）2, and traces of non-crystalline MgF2 and CaF2. The Zn-Ca-Ce-P coating is more compact than the Zn-Ca-P coating due to the formation of CePO4, and displays better corrosion resistance than the Zn-Ca-P coating. Both coatings protect the AZ31 Mg substrate only during an initial immersion period. The micro-galvanic corrosion between the coatings and their substrates leads to an increase of hydrogen evolution rate （HER） with extending the immersion time. The addition of Ce promotes the homogenous distribution of Ca and formation of hopeite. The Zn-Ca-Ce-P coating has the potential for the primer coating on magnesium alloys.展开更多
Ce-doped ZnO microspheres were solvothermally prepared, and their microstructure, morphology, photoluminescence, and gas sensing were investigated by X-ray diffractometer, field emission scanning electron microscopy, ...Ce-doped ZnO microspheres were solvothermally prepared, and their microstructure, morphology, photoluminescence, and gas sensing were investigated by X-ray diffractometer, field emission scanning electron microscopy, transmission electron microscopy, fluorescence spectrometer and gas sensing analysis system. The results showed that the Ce-doped ZnO microspheres were composed of numerous nanorods with a diameter of 70 nm and a wurtzite structure. Ce-doping could cause a morphological transition from loose nanorods assembly to a tightly assembly in the microspheres. Compared with pure ZnO, the photoluminescence of the Ce-doped microspheres showed red-shifted UV emission and an enhanced blue emission. Particularly, the Ce-doped ZnO sensors exhibited much higher sensitivity and selectivity to ethanol than that of pure ZnO sensor at 320 °C. The ZnO microspheres doped with 6% Ce (mole fraction) exhibited the highest sensitivity (about 30) with rapid response (2 s) and recovery time (16 s) to 50×10?6 ethanol gas.展开更多
The nanocomposite coating is obtained by electrochemical deposition of the zinc plating solution with ceria nanoparticles (mean diameter 30 nm). The effect of ceria nanoparticles on the electrodeposited zinc coating i...The nanocomposite coating is obtained by electrochemical deposition of the zinc plating solution with ceria nanoparticles (mean diameter 30 nm). The effect of ceria nanoparticles on the electrodeposited zinc coating is stu died by weight loss test, inductively copuled plasma quantometer (ICP), scanning electron microscopy (SEM) and X ray diffraction (XRD), respectively. It is found that under the same electrodeposition conditions, the corrosion resistance of the nanocomposite coating increases obviously while that of the micron composite coating only improves slightly; The ceria content of the nanocomposite coating is more than that of the micron composite coating. Ceria nanoparticles modify the surface morphology and crystal structure of the zinc matrix in correlation with the increase of corrosion resistance.展开更多
[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive applica...[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive application of rare earth. [Method] By using rare earth elements La3＋ and Ce3＋, and nutritional and toxic heavy metal element Zn2＋ as stress factors, the effects of these three elements on the germination of rice seeds, growth and development of seedlings were studied and compared by using tissue culture method. [Result] La3＋, Ce3＋ and Zn2＋ had no significant effect on germi- nation rate of rice seeds but significant inhibition effects on the growth of roots and shoots of rice seedlings, and the inhibition effects of rare earth elements in high concentrations were stronger than Zn2＋; the content of soluble protein in rice roots showed a rising-decreasing trend with the increasing concentrations of three metal ions, La3＋ and Ce3＋ were more sensitive than Zn2＋; the activities of CAT and POD increased with the increasing concentrations of La3. and Ce3＋, while the SOD activity had shown the tendency of decreased first and increased later; the three metal ions all could significantly stimulate the rapid accumulation of MDA in rice roots. La3＋ and Ce3＋ had stronger toxic effects at high concentrations than Zn2＋, [Conclusion] Toxic mechanism of rare earth elements La＋ and Ce3. is similar to that of heavy metal el- ement Zn2＋. Rare earth might become a new type of pollution in the long run.展开更多
文摘合成了锌-铝-铈三元类水滑石(Zn Al Ce-CO3-LDHs),确定最佳合成条件为:p H=8、Ce/Al=0.05,反应温度及陈化温度分布为40、100℃。将Zn Al Ce-CO3-LDHs改性后测试其作为PVC稳定剂的热稳定效果,结果表明:Zn Al CeCO3-LDHs是一种高效的PVC热稳定剂,改性后稳定效果更佳,在钙锌稳定剂中掺入少许Zn Al Ce-CO3-LDHs,能够大幅提高钙锌稳定剂稳定效果。
基金Project(51571134)supported by the National Natural Science Foundation of ChinaProject(2014TDJH104)supported by the SDUST Research Fund+1 种基金the Joint Innovative Centre for Safe and Effective Mining Technology and Equipment of Coal Resources,Shandong Province,ChinaProject(cstc2012jj A50034)supported by the Natural Science Foundation of Chongqing,China
文摘Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coatings were investigated through energy-dispersive X-ray spectroscopy （EDS）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, electron probe micro-analysis （EPMA） and scanning electron microscopy （SEM） together with hydrogen volumetric and electrochemical tests. The results indicate that both coatings predominately contain crystalline hopeite （Zn3（PO4）2·4H2O）, Mg3（PO4）2 and Ca3（PO4）2, and traces of non-crystalline MgF2 and CaF2. The Zn-Ca-Ce-P coating is more compact than the Zn-Ca-P coating due to the formation of CePO4, and displays better corrosion resistance than the Zn-Ca-P coating. Both coatings protect the AZ31 Mg substrate only during an initial immersion period. The micro-galvanic corrosion between the coatings and their substrates leads to an increase of hydrogen evolution rate （HER） with extending the immersion time. The addition of Ce promotes the homogenous distribution of Ca and formation of hopeite. The Zn-Ca-Ce-P coating has the potential for the primer coating on magnesium alloys.
基金Project(61079010)supported by the National Natural Science Foundation of China and the Civil Aviation Administration of ChinaProject(3122013P001)supported by the Significant Pre-research Funds of Civil Aviation University of ChinaProject(MHRD20140209)supported by the Science and Technology Innovation Guide Funds of Civil Aviation Administration of China
文摘Ce-doped ZnO microspheres were solvothermally prepared, and their microstructure, morphology, photoluminescence, and gas sensing were investigated by X-ray diffractometer, field emission scanning electron microscopy, transmission electron microscopy, fluorescence spectrometer and gas sensing analysis system. The results showed that the Ce-doped ZnO microspheres were composed of numerous nanorods with a diameter of 70 nm and a wurtzite structure. Ce-doping could cause a morphological transition from loose nanorods assembly to a tightly assembly in the microspheres. Compared with pure ZnO, the photoluminescence of the Ce-doped microspheres showed red-shifted UV emission and an enhanced blue emission. Particularly, the Ce-doped ZnO sensors exhibited much higher sensitivity and selectivity to ethanol than that of pure ZnO sensor at 320 °C. The ZnO microspheres doped with 6% Ce (mole fraction) exhibited the highest sensitivity (about 30) with rapid response (2 s) and recovery time (16 s) to 50×10?6 ethanol gas.
文摘The nanocomposite coating is obtained by electrochemical deposition of the zinc plating solution with ceria nanoparticles (mean diameter 30 nm). The effect of ceria nanoparticles on the electrodeposited zinc coating is stu died by weight loss test, inductively copuled plasma quantometer (ICP), scanning electron microscopy (SEM) and X ray diffraction (XRD), respectively. It is found that under the same electrodeposition conditions, the corrosion resistance of the nanocomposite coating increases obviously while that of the micron composite coating only improves slightly; The ceria content of the nanocomposite coating is more than that of the micron composite coating. Ceria nanoparticles modify the surface morphology and crystal structure of the zinc matrix in correlation with the increase of corrosion resistance.
基金Supported by National Natural Science Foundation of China (30900071)PhD Research Start-up Fund of Shandong University of Technology (4041-406027)~~
文摘[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive application of rare earth. [Method] By using rare earth elements La3＋ and Ce3＋, and nutritional and toxic heavy metal element Zn2＋ as stress factors, the effects of these three elements on the germination of rice seeds, growth and development of seedlings were studied and compared by using tissue culture method. [Result] La3＋, Ce3＋ and Zn2＋ had no significant effect on germi- nation rate of rice seeds but significant inhibition effects on the growth of roots and shoots of rice seedlings, and the inhibition effects of rare earth elements in high concentrations were stronger than Zn2＋; the content of soluble protein in rice roots showed a rising-decreasing trend with the increasing concentrations of three metal ions, La3＋ and Ce3＋ were more sensitive than Zn2＋; the activities of CAT and POD increased with the increasing concentrations of La3. and Ce3＋, while the SOD activity had shown the tendency of decreased first and increased later; the three metal ions all could significantly stimulate the rapid accumulation of MDA in rice roots. La3＋ and Ce3＋ had stronger toxic effects at high concentrations than Zn2＋, [Conclusion] Toxic mechanism of rare earth elements La＋ and Ce3. is similar to that of heavy metal el- ement Zn2＋. Rare earth might become a new type of pollution in the long run.
