Luminescence Properties of Eu~(2 ) and Mn~(2 ) Co-Doped Ca_8Mg(SiO_4)_4Cl_2

The green phosphor for white LED, Ca8Mg(SiO4)4Cl2∶Eu2+, Mn2+, was synthesized by high temperature solid state reaction under reducing atmosphere. During the process of the phosphor prepared, the excess CaCl2 can improve the intensity of emission. The experimental results indicate that there is an effective energy transfer from Eu2+ to Mn2+in Ca8Mg(SiO4)4Cl2 host. This kind of energy transfer may be due to resonance transfer, and this energy transfer is limited.     

500kV海底电缆油泵站远程监控系统研究

海底电缆油泵站作为海南联网工程的重要组成部分,满足3根海底电缆用油及压力需求.油泵站系统投运9年,出现多起故障,当海底电缆油泵站控制系统故障后,无法监控油泵站的运行状况,无法手动对油泵站系统进行就地操作及了解海底电缆的供油情况.研究海底电缆油泵站的工作原理,打破原有代码屏蔽,开发一套海底电缆油泵站远程监控系统,实现对油泵站的远程监控.     

Study on purification and application of novel precipitant for ceria-based polishing powder

Novel precipitant prepared through carbonation with MgCl2 wastewater generated from rare earth extraction separation process and low-price dolomite as raw materials was studied in this paper. The purification methods of novel precipitant by adding appropriate oxidizing agent were studied. It was found that optimal purification result could be achieved with sodium hypochlorite as iron removal reagent and the iron removal rate could reach up to 90% when the adding amount was 0.1 vol.%. During the preparation, the particle size and distribution of ceria-based polishing powder were affected obviously by the parameters such as concentration, reaction temperature and feeding rate. The results showed that ceria-based polishing powder with D50 =2.5-3.5 μm and the particle size distribution of 0.65-0.75 μm could be prepared when the concentration of CeCl3 was 0.6 mol/L, the reaction temperature was maintained at 50 °C and the feeding speed was controlled at 25 ml/min. Compared with commercial powder, the self-made polishing powder had roughly the same cutting amount, but the surface finish of polished glass was better than that of commercial polishing powder.     

钙钛矿催化材料La1-xCexCoO3+δ的制备、表征及甲烷燃烧催化性质

采用柠檬酸发泡法制备了钙钛矿LaCoO3催化材料;研究了Ce对La进行掺杂替代对催化材料性能的影响;通过BET、XRD、SEM等手段对催化材料进行了物性表征;以甲烷完全燃烧为目标反应,研究了钙钛矿La1-xCexCoO3 δ的催化性能.结果表明:铈掺杂对材料晶相有较大影响,当掺杂量x小于0.3时,粉体晶型基本不变,而当掺杂量达到0.5时,有明显CO3O4晶相出现,LaCoO3钙钛矿晶相完整性遭到破坏,当掺杂量大于0.7时,钙钛矿晶相大大弱化甚至消失;LaCoO3是一种性能优良的甲烷燃烧催化材料,Ce的掺杂替代对催化材料活性有明显影响,并增强了催化材料的高温稳定性能,铈最佳掺杂量为0.3;前驱体经700℃焙烧形成了较为完整的钙钛矿晶型,经800℃焙烧后,催化材料最高活性为:t10%=390℃,t90%=603℃.     

Synthesis of Spherical （Y, Gd） BO3 ： Eu^3＋ Phosphor Using W/O Emulsion System

Spherical （Y, Gd）BO3：Eu^3＋ phosphor particles with a narrow size distribution（2 -4 μm） was obtained by firing the Y-Gd-Eu-BO3 precursor prepared in a W/O style emulsion system. In the W/O emulsion system, kerosene, used as oil phase, was mixed with Span 80 and Tween 80 compounds which were employed as the emulsifier with an HLB （hydrophile-lipophile balance） value of 5.2- 5.3. Both rare earths （Y, Gd and Eu） nitrate and boric acid solution or ammonia solution were used as aqueous phase. The synthesis conditions, such as emulsion composition, emulsifying style, precipitation reaction process, reaction temperature, morphology control, and so on, were investigated, and the optimum synthesis conditions for preparing spherical （Y, Gd）BO3：Eu^3＋ phosphor was obtained. The phosphor was characterized by XRD, SEM, laser particle size analysis, emission and excitation spectrum under vacuum ultraviolet （VUV）, and so on. The phosphor synthesized using the water-in-oil emulsion method with median diameter （D50） of 2 - 4 μm shows agreeable photoluminescence （PL） property and sphericity. The main emission peak appears at about 593 nm, which corresponds to ^5D0→^7F1 transition （magnetic-dipole transition） of the Eu^3＋ ion. The cell parameters and powder diffraction data were indexed. The structure of the phosphor belongs to the hexagonal system with space group P63/m.     

磷矿中微量稀土提取技术研究进展

磷矿中伴生的微量稀土作为一种潜在的稀土资源,开展综合回收稀土的研究具有重要意义.简单介绍了磷矿中稀土含量及分布状况,综述了磷化工过程中回收稀土的最新研究进展,分别介绍了回收稀土的方法及现状,对未来磷矿中微量稀土提取技术研究方向进行了探讨.     

Study on Effect of Flux on CeMgAl11O19：Tb^3＋ Phosphor

High calcination temperature is an important factor in the preparation process of CeMgAl11O19:Tb^3 . To decrease the temperature, different fluxes (H3BO3, MgF2 and AlF3) were tested in order to compare their influence on the luminescence property and particle size distribution of CeMgAl11O19: Tb^3 . The result shows that when the content of MgF2 is 0.1 mol/mol, the intensity of luminescence can attain a maximum. Furthermore, MgF2 can improve the particle size quality of the phosphor. So MgF2 can take the place of the conventional flux H3BO3 to prepare high quality CeMgAl11O19:Tb^3 phosphor. In addition, the relation between phosphor property and content of AlF3 was also studied. The crystal structure of the phosphor was analyzed by XRD method. The phase composition analysis shows that the reason of decrease of the brightness of CeMgAl11O19:Tb^3 phosphor is the emergence of TbAlO3 and α-Al2O3 during the preparation process.     

Co-Precipitation Preparation and Luminescent Behavior of (Y,Gd)BO3∶ Eu Phosphor

(Y,Gd)BO3∶ Eu phosphors were prepared by co-precipitation precursors, and luminescent properties were investigated. The precursors were synthesized by introducing hydroxyl ion to mixed solution of rare earth nitrates and boric acid, either through adding ammonia(precursor 1)or through controlled release of hydroxyl ion of urea(precursor 2). The precursors were fired in air at 1000 ℃ for 2 h. Resulted phosphor synthesized with precursor 1 has non-uniformed particle with mean diameter of about 3 μm, while that with precursor 2 exhibits uniformed near spherical-like morphology with mean diameter of about 300 nm. Phosphors with the two methods exhibit same crystal structure as that of commercial one. Emission spectra of the samples indicate that the sample prepared with precursor 2 shows relative higher intensity(exited by 172 nm VUV)than that prepared with the other precursor.     

油泵站加油工具车液压系统及故障排除

本文首先介绍了液压系统的分类和故障类型,以液压系统油的清洁度为切入点,介绍作者设计的油泵站加油工具车的液压系统设计原理并介绍其在海南联网工程500kV充油海底电缆油泵站中的应用,最后从多角度介绍了该液压系统的常见故障分析与故障处理方法。     

近缆抛锚技术在海南联网二回路由勘察中的应用

介绍了近缆抛锚技术在海南联网二回路由勘察中的应用方法、实施过程,在确保海南联网一回海底电缆安全稳定运行的前提下,完成了海南联网二回路由勘察施工作业,极大地降低了因抛锚施工给运行中的海底电缆带来的安全风险。