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.     

Luminescence Properties of Eu^2 ＋ and Mn^2 ＋ Co-Doped CasMg（SiO4）4Cl2

The green phosphor for white LED, Ca8Mg(SiO4)4C12:Eu^2 , Mn^2 , was synthesized by high temperature solid state reaction under reducing atmosphere. During the process of the phosphor prepared, the excess CaC12 can improve the intensity of emission. The experimental results indicate that there is an effective energy transfer from Eu^2 to Mn^2 in Ca8Mg(SiO4)4Cl2 host. This kind of energy transfer may be due to resonance transfer, and this energy transfer is limited     

湿法磷酸生产过程中控制硫酸钙结晶的研究

采用河北矾山磷矿为原料在间歇实验装置中进行二水物湿法礴酸模拟生产,研究了湿法磷酸生产工艺条件及活性添加剂对硫酸钙晶体平均尺寸和结晶形态的影响.研究结果表明,较高的体系温度及低的磷酸质量分数均有利于硫酸钙晶体的长大;控制合适的SO4 2-质量分数有利于硫酸钙晶体的生长,在硫酸化学计量比为1.1时可形成易于洗涤和过滤的类球状聚晶;添加不同活性添加剂时,可得到不同形态的硫酸钙结晶.     

利用氟铝络合物溶液合成冰晶石的研究

以氟碳铈矿氧化焙烧-稀硫酸浸出-萃取洗涤得到的氟铝络合物溶液为原料,通过补充氟盐和钠盐控制一定的F/Al比、Na/Al比,并调节pH值得到冰晶石沉淀,经过滤、洗涤、烘干得冰晶石产品.重点探讨了合成冰晶石的原理,研究了溶液pH值、F/Al比、Na/Al比和合成温度等对冰晶石产品质量及回收率的影响,并对制备工艺进行了优化.研究结果表明:溶液pH值在5左右、F/Al比在5.5～6之间、Na/Al比在3.0～3.3之间,合成温度在95℃以上合成的冰晶石符合国家标准,且氟、铝的回收率均可达95%以上.     

500 kV充油海底电缆导体温度分布式光纤传感监测及应用

依据海南联网系统500 kV海底电缆捆绑特殊海底光缆的实际情况,通过分布式光纤传感技术结合经有限元仿真模型优化的IEC60287热路模型的方法可以监测海底电缆内部的温度分布。在实验室中搭建岸上模拟实验平台,利用中压电缆捆绑光纤的结构进行捆绑电缆岸上模拟实验。同时,将经验证的温度监测方法应用于海南联网系统500 kV海底电缆,以C相空气段为例监测捆绑电缆光单元的温度。采用有限元仿真计算电缆表面的温度,根据电缆表面的温度基于热路模型推导出对应的导体温度,得到电缆导体在实际运行过程中的温度变化。岸上模拟实验测量的导体温度与数值计算得到导体温度的误差低于1.77%, 验证了海底电缆导体温度监测方法的准确性。     

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.     

Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-（2-ethylhexyl） phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.     

电感耦合等离子体原子发射光谱法测定磷矿中微量稀土元素

样品经碱熔,溶液提取,沉淀富集后得到只含稀土元素的溶液,采用电感耦合等离子体原子发射光谱(ICP-AES)法测定磷矿中15种稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y。主要考察了共存元素间的干扰情况,选择无干扰或干扰量对分析结果可以忽略不计的谱线为最佳分析线,标准曲线法直接测定磷矿中稀土元素。本法测定结果与ICP-MS测定结果相符合,可满足日常分析要求。