采用氧化物固相法制备(LaMn0.8Al0.2O3)1-x(Al2O3)x(0.05≤x≤0.2)系列负温度系数(Negative Temperature Coefficient,NTC)热敏陶瓷材料。利用热重-差热(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(EDS)、阻温特性以及...采用氧化物固相法制备(LaMn0.8Al0.2O3)1-x(Al2O3)x(0.05≤x≤0.2)系列负温度系数(Negative Temperature Coefficient,NTC)热敏陶瓷材料。利用热重-差热(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(EDS)、阻温特性以及老化性能测试等手段,确定了材料粉体最佳煅烧温度,表征了陶瓷体物相、形貌、元素含量、电学性能、稳定性与Al2O3含量的关系。结果表明:(LaMn0.8Al0.2O3)1-x(Al2O3)x(0.05≤x≤0.2)系列热敏陶瓷材料电阻率随着Al2O3含量增加显著增大,但材料常数B值增加平缓。当x=0.15时,该陶瓷材料呈现出低B(2816.44 K)、高阻(11893.89?·cm)的优良电学特性。热敏电阻经125℃老化500 h,阻值漂移(ΔR/R)均小于0.94%。展开更多
做 Cu 的 LaMn1-xCuxO3 (x=0.05-0.30 ) 系统的磁性小心地在 2-300 K 的温度范围被学习。可见意外落下在危险性和零地的凉下来的 dc 磁化为 dilute x 弄弯的交流被观察[?] 0.10 接近 100K，它取决于测量频率和磁场。交流危险性，磁性的...做 Cu 的 LaMn1-xCuxO3 (x=0.05-0.30 ) 系统的磁性小心地在 2-300 K 的温度范围被学习。可见意外落下在危险性和零地的凉下来的 dc 磁化为 dilute x 弄弯的交流被观察[?] 0.10 接近 100K，它取决于测量频率和磁场。交流危险性，磁性的松驰的观察，和关键字段的存在的频率依赖上的大小显示异例能被归因于卡住效果的领域墙。这被球 milled 的结果直接与体积材料相比证明缩放 nano 的粉末对应物。[从作者抽象]展开更多
A series of pre-reduced LaMn1–xCuxO3 (0≤x<1) catalysts for methanol synthesis from CO2 hydrogenation were prepared by a sol-gel method. The catalytic performances were strongly dependent on the copper content. XR...A series of pre-reduced LaMn1–xCuxO3 (0≤x<1) catalysts for methanol synthesis from CO2 hydrogenation were prepared by a sol-gel method. The catalytic performances were strongly dependent on the copper content. XRD investigation revealed that the single perovskite structure could be preserved after being reduced, when the substitution for Mn by Cu was less than 50%. The Cu-doped (x=0.5) LaMnO3 was much more active than the other catalysts for reaction, showing CO2 conversion up to 11.33% and methanol sele...展开更多
采用溶胶-凝胶法制备了钙钛矿型氧化物LaMn 1-x Co xO 3,并以其为光催化剂对模型染料酸性品红进行催化降解实验。研究了Co掺杂量、pH值、染料浓度、催化剂的投加量、以及外加氧化剂H 2O 2投加量等因素对其光催化活性的影响。研究结果表...采用溶胶-凝胶法制备了钙钛矿型氧化物LaMn 1-x Co xO 3,并以其为光催化剂对模型染料酸性品红进行催化降解实验。研究了Co掺杂量、pH值、染料浓度、催化剂的投加量、以及外加氧化剂H 2O 2投加量等因素对其光催化活性的影响。研究结果表明:Co掺杂量x=0.4时,在催化剂投加量0.2 g/L,酸性品红的浓度为10 mg/L,溶液的pH值为7时,酸性品红的降解率可达97%,H 2O 2可提高光催化降解反应的速率。展开更多
文摘采用氧化物固相法制备(LaMn0.8Al0.2O3)1-x(Al2O3)x(0.05≤x≤0.2)系列负温度系数(Negative Temperature Coefficient,NTC)热敏陶瓷材料。利用热重-差热(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(EDS)、阻温特性以及老化性能测试等手段,确定了材料粉体最佳煅烧温度,表征了陶瓷体物相、形貌、元素含量、电学性能、稳定性与Al2O3含量的关系。结果表明:(LaMn0.8Al0.2O3)1-x(Al2O3)x(0.05≤x≤0.2)系列热敏陶瓷材料电阻率随着Al2O3含量增加显著增大,但材料常数B值增加平缓。当x=0.15时,该陶瓷材料呈现出低B(2816.44 K)、高阻(11893.89?·cm)的优良电学特性。热敏电阻经125℃老化500 h,阻值漂移(ΔR/R)均小于0.94%。
基金Supported by the National Natural Science Foundation of China under Grant Nos 10674092, 10774097 and 10504019, the Specialized Research Fund for Doctoral Programme of Higher Education under Grant No 20050280004, Shanghai Nano-Technology Promotion Center and the Science and Technology Committee of Shanghai Municipality under Grant No 0652nm046, and the Shanghai Leading Academic Disciplines Project under Grant No T0104.
文摘做 Cu 的 LaMn1-xCuxO3 (x=0.05-0.30 ) 系统的磁性小心地在 2-300 K 的温度范围被学习。可见意外落下在危险性和零地的凉下来的 dc 磁化为 dilute x 弄弯的交流被观察[?] 0.10 接近 100K，它取决于测量频率和磁场。交流危险性，磁性的松驰的观察，和关键字段的存在的频率依赖上的大小显示异例能被归因于卡住效果的领域墙。这被球 milled 的结果直接与体积材料相比证明缩放 nano 的粉末对应物。[从作者抽象]
文摘A series of pre-reduced LaMn1–xCuxO3 (0≤x<1) catalysts for methanol synthesis from CO2 hydrogenation were prepared by a sol-gel method. The catalytic performances were strongly dependent on the copper content. XRD investigation revealed that the single perovskite structure could be preserved after being reduced, when the substitution for Mn by Cu was less than 50%. The Cu-doped (x=0.5) LaMnO3 was much more active than the other catalysts for reaction, showing CO2 conversion up to 11.33% and methanol sele...
