Synthesis of lanthanum hydroxide and lanthanum oxide nanoparticles by sonochemical method

In this work lanthanum hydroxide nanoparticles were synthesized by sonochemical method. La₂O₃ nanoparticles were obtained after calcination of the La(OH)₃ nanoparticles precursor in air at 600 °C for 2 h. The effect of some parameters such as concentration of precursors, pulse time of sonication, time of sonication, and addition of PEG as surfactant on the morphology and the particle size were studied. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectrum (XPS) and Fourier transform infrared (FT-IR) spectra.     

固体氧化物燃料电池电极材料研究 Ⅱ.甲烷氧化转化阳极材料的制备与表征

制备了适合固体氧化物燃料电池中甲烷氧化转化的阳极材料Ni/La(Sr)MnO_3.利用差热分析和热重分析研究了该阳极材料的合成条件.应用电子探针、X射线衍射和扫描电镜分别对材料的组成和结构进行表征.对Ni/La(Sr)MnO_3的电导性能进行了研究,并与Ni/YSZ的电导性能进行比较,分析了影响阳板材料电导性能的主要因素.     

Characterization and Stability of La0.5Sr0.5CoO2.91 Perovskite-Type Oxide

Compositely doped oxide La0.5Sr0.5CoO2.91 （LSC） was synthesized using solid state reaction and citric acid-nitrate low temperature self-propagating combustion methods. The crystal structure and the particle size micrograph of LSC powders synthesized by different methods were investigated with XRD and SEM. The experimental results show that the single perovskite phase of LSC can be synthesized by solid state reaction method, but LaSrCoO4 phase appears in LSC powder synthesized by citric acid-nitrate low temperature self-propagating combustion method. The LSC particle by citric acid-nitrate low temperature self- propagating combustion method has smaller size. To analyze the character of cathode material based on Ceo.gGdo.101.95（GDC） electrolyte, two types of cathode wafers were fabricated with the two kinds of LSC and GDC powders at the mass rate of 6：4, respectively. The electrical conductivity of the sintered samples was measured by four probe DC method from 300 to 800 ℃. The cathode with LSC particle by citric acid- nitrate low temperature self-propagating combustion method has higher electrical conductivity. In order to investigate the stability, the two samples were put into the muffle furnace to heat up in air at 800℃for 800 h. To analysis the reason for reduced electrical conductivity, the crystal structure and the particle micrograph of the cathode wafers before and after an exposure were investigated with XRD and SEM. The result shows that new crystal structure appears in both the two kinds of cathode wafers and crystal micrographs change a lot.     

La对富Ni的NiAl系合金组织与性能的影响

通过压缩和三点弯曲试验对加Ｌａ后富Ｎｉ的ＮｉＡｌ合金力学性能进行了考察。结果发现,Ｌａ的加入可以明显地细化合金的晶粒及改善ＮｉＡｌ和Ｎｉ３Ａｌ的两相分布。适量Ｌａ可提高合金的室温屈服强度和塑性,但超过一定的含量,合金的塑性反而有所下降。在合金中,引入Ｂ韧化的Ｎｉ３Ａｌ对合金的塑性有利。     

Phase Formations and Electrical Properties of Various (Bi, La)4Ti3O12 Thin Films by Chemical Solution Deposition

The phase formation and electrical properties of (Bi, La)₄Ti₃O₁₂ (BLT) thin film and V-, Sm-doped BLT thin films prepared by the chemical solution deposition method on Pt/TiO₂/SiO₂/Si substrates have been investigated. It was observed that the microstructure and electrical properties of BLT thin films dramatically varied with V- and Sm-doping. The crystallinity and grain size of BLT thin films were definitely increased by V- and Sm-doping into BLT films, which resulted in the enhancement of remanent polarization in doped BLT films. The remanent polarization (Pr) of Sm-doped BLT films annealed for 3 min by an RTA system was about 9 C/cm². The V- and Sm-doped BLT films also exhibited good fatigue characteristics under bipolar stressing to 10¹⁰ cycles.     

La2O3/TiO2纳米粒子超声光催化降解邻硝基苯酚

以钛酸丁酯为原料,用溶胶-凝胶(Sol-gel)法制备了La2O3/TiO2纳米粒子.采用X光衍射仪对粉体的粒径、物相进行了表征.研究了超声光催化协同降解水中邻硝基苯酚的效果,考察了超声波声强、反应温度和催化剂投加量对邻硝基苯酚降解速率的影响.研究结果表明,超声光催化协同降解要比单独超声波或光化学处理效果显著,证实了声光联合技术具有明显的协同效应.     

等离子喷涂纳米La2Zr2O7和纳米ZrO2涂层隔热性能比较

采用大气等离子喷涂了一种新型的纳米La2Zr2O7热障涂层,比较了纳米La2Zr2O7和纳米ZrO2涂层的隔热性能.结果表明,与纳米YPSZ涂层相比,纳米结构的La2Zr2O7具有更好的隔热性能.并讨论了涂层显微组织对涂层隔热性能的影响.     

Prevention of La^3＋ on DNA Damage Caused by Hg^2＋ from Fish Intestines

Recent studies have shown that heavy metals havebecome the most important contaminants in the environ-ment.Some heavy metals ,such as Pb, Cd, Hg, As ,Co,and Cr have genetic toxicity. They disturb DNAmetabolismand lead to aberrance of chromosome andDNA[1].…     

La2O3在低质坯料卫生瓷乳浊釉中的应用

以低质珍珠岩为主要原料,通过正交设计,研制出低温烧成卫生瓷坯料配方,针对其坯体色深、白度低的情况,成功研制出La2O3基高强乳浊釉对其有效遮盖.经生产实际运行,产品指标均达到企业标准要求,不仅实现了用低质料生产优质卫生瓷的目的,同时显著降低了坯体的烧成温度,缩短了烧成周期,经济效益显著.     

Effects of La2O3/Li2O/TiO2- Coating on Electrochemical Performance of LiCoO2 Cathode

Conventional cathode material （LiCoO2） was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode material was characterized by SEM, XRD, and Auger electron spectroscopy. The performance of the cells with the modified cathode material was examined, including the cycling stability, the diffusion coefficient under different voltages, and the C-rate discharge. The results showed that the cell composed of the coated cathode material discharged at a large current density, and possesses a stable cycle performance in the range from 3.0 to 4.4 V. It was explained that the rate of Li ion diffusion increased in the cell while using La2O3/Li2O/TiO2-coated LiCoO2 as the cathode and the coating layer may act as a faster ion conductor （La2O3/Li2O/TiO2）.