Intense blue-emitting Ca₂PO₄Cl:Eu²⁺ phosphor for near-ultraviolet converting white light-emitting diodes

A blue phosphor Ca2PO4Cl:Eu2+(CAP:Eu2+) was synthesized by solid state reaction.The Ca2PO4Cl:Eu2+ exhibited high quantum efficiency and excellent thermal stability.The luminescent intensity of Ca2PO4Cl:Eu2+ was found to be 128% under excitation at 380 nm,149% under 400 nm,and 247% under 420 nm as high as that of BaMgAl10O17:Eu2+.The optimal doping concentration was observed to 11 mol.% of CAP:Eu2+.The energy transfer between Eu2+ ions in CAP were occurred via electric multipolar interaction,and the critical transfer distance was estimated to be 1.26 nm.A mixture of blue-emitting Ca2PO4Cl:Eu2+,green-emitting(Ba,Sr)2SiO4:Eu2+ and red-emitting CaAlSiN3:Eu2+ phosphors were selected in conjunction with 400 nm chip to fabricate white LED devices.The average color-rendering index Ra and correlated color temperature(Tc) of the white LEDs were found to be 93.4 and 4590 K,respectively.The results indicated that it was a promising candidate as a blue-emitting phosphor for the near-UV white light-emitting diodes.     

DMSH—支持直接操纵的用户接口管理系统

本文介绍一个用于生成直接操纵用户接口的用户管理系统(ULMS-UserInterface Management System)——直接操纵用户接口自动生成系统DMSH(Direct Manipulation SHell)的设计与实现,该系统提供图形操作对象和接口描述语言供用户使用。生成用户接口,并可随时扩充;接口描述语言具有第四代语言的特征——直观性和非过程性。     

921台湾地震近断层强地面运动的周期和幅值特性

本文以 92 1台湾地震的 30组近断层加速度时程为样本 ,研究了他们的周期(频率 )和幅值的随机特性 ,主要内容包括峰值加速度PGA、特征时刻与持时、幅值概率密度谱、幅值包线、周期频度谱以及穿零率函数。提出了二次峰点法求包线的方法 ,并建立了相应的数学模型     

The study of microstructure and phosphorus distribution in converter slag

An efficient slagging is a key process to improve the dephosphorization ability in converter operation. The microstructure analyses can provide the information of phosphorus distribution in various mineral phases to feature completely the dephosphorization process.Two kinds of converter slags were investigated in this study, including conventional slag with high basicity and dephosphorization slag with low basicity.The characteristics of high basicity converter slag have been reported widely.However,the ...     

新城市职责下的规划:1990年以来的台湾经验

进入新世纪以来，在全球城市发展环境中新的关键性问题正在逐步显现。面对城市人口在本世纪中将超过半数的预期，规划授权已经开始从发展浪潮中的精英转向社会大众，其规模和范畴已经超出我们的想象。人口超过2000万的大都市地区正在快速形成，而且可以确定未来十年中它们仍将变得更大。同时，当前对地球资源的利用方式明显是不可持续的，继续沿用此种发展方式必然会导致严重的环境和社会灾难。具有社会责任感的规划师和设计师，无论是在从事主流的专业实践还是在探索多种替代途径，     

物业管理大楼冷水主机设备的维护质量及成本分析

基于维护时收集的数据,以生存分析方法构建了冷水主机的生存曲线,识别了故障事件间隔时间的概率模型,并估计了模型参数的极大似然估计量。利用统计假设检验法比较了2台冷水主机生存率的差异显著性,藉以推断这2台冷水主机维护质量的差异。利用随机过程更新理论确立了设备故障事件发生的计数过程及累积维修成本随机过程的统计特性,并建立了期望累积维修成本与使用时间的关系。结果显示,故障事件间隔时间的概率模型近似指数分布,故障事件发生次数随时间增加的计数过程可以泊松过程模拟。     

ITO Films Prepared by Long-throw Magnetron Sputtering without Oxygen Partial Pressure

This study has investigated the influence of the radio frequency (rf) power and working pressure on the properties of indium tin oxide (ITO) thin films, which were prepared by long-throw rf magnetron sputtering technique at room temperature. For 200 nm thick ITO films grown at room temperature in pure argon pressure of 0.27 Pa and sputtering power of 40 W, sheet resistance was 26.6 ?/sq. and transmittance was higher than 88% (at wavelength 500 nm). An X-ray diffraction analysis of the samples deposited at r...     

SOLUTION FOR PRESSURE DISTRIBUTION IN SQUEEZE FILM DAMPER WITH ELECTROHYDRAULIC ACTIVE CONTROL

ＮＯＴＡＴＩＯＮＳａ———ＨａｌｆｌｅｎｇｔｈｏｆｓｔａｔｉｃｐｒｅｓｓｕｒｅｒｅｇｉｏｎＣ———Ｒａｄｉｕｓｃｌｅａｒａｎｃｅｅ———Ｅｃｅｎｔｒｉｃｄｉｓｔａｎｃｅε———Ｅｃｅｎｔｒｉｃｒａｔｉｏ,ε＝ｅ／ＣＬ———Ｂｅａｒｉｎｇｌｅｎｇｔｈθ...     

The Formation of Nano-Size SiO_2 Thin Film on an Aluminum Plate with Hexamethyldisilazane (HMDSA) and Hexamethyldisiloxane (HMDSO)

This study is using HMDSA (C6H19NSi2) or HMDSO (C6H18OSi2) vapor into C3H8/air premixed flames to form SiO2 thin film on the surface of an aluminum plate. With the addition of HMDSO or HMDSA to premixed flames, an orange secondary flame or a flame brush appeared and was contributed to the formation of Sio2 particles. Based upon the EDS, XPS and FTIR analysis, it is believed that the synthesized products consist of mainly SiO2 and a small amount of SiO. The pure SiO2 crystal structure, was proved by XRD analysis, which may form from the SiO2 amorphous structure after high temperature (1300C) thermal treatment. The nano-size SiO2 particles, which ranged from 2.5-25 nm, are proved by analysis of the BET and TEM. A 2-D CFD-RC code with 12 reduced chemical reaction mechanism, based upon the SIMPLER procedure, was successfully employed to predict the flame temperature and both of the SiO2 and SiO concentration profiles. Compared with the experimental results, the calculated temperature profiles in the post-fl     

Manufacturing of Porous Alumina Ceramic by Gel Casting

Various quantities of non-toxic monomer (2-hydroxyethyl methacrylate, HEMA) was added to form porous alumina ceramic by gel casting process. Pure water, monomer, cross-linker (N, N'-methylene-bis-acrylamide (MBAm)), and dispersant (ammonium salt of poly (methacrylic acid), PAS) were combined to form an aqueous solution, which added alumina powder and was milled to form alumina slurry with zirconia balls for 240 minutes. An initiator (ammonium persulfate, APS) was added to the alumina slurry with a vacuum mi...