基于CAN总线的污水加药控制系统设计

针对当前污水处理过程中加药控制效率低、絮凝效果不稳定的缺点,开发了一种具有CAN总线通讯功能的加药自动控制系统。并介绍了污水处理过程中加药系统的工作原理和基本结构,对控制系统的硬件电路和软件流程进行了详细说明。在实际运行中取得良好的应用效果。     

浅谈风电场工程风机安装施工工艺

本文主要介绍了风机安装施工工艺过程,重点说明了塔筒、机舱、风叶的组装及吊装过程并配备了详细的图片。希望大家对风电的安装过程有所了解。     

Photoluminescence Characteristics of Gd2Mo3O9 ： Eu Phosphor Particles by Solid State Reaction Method

Eu^3＋-doped Gd2Mo3O9 was prepared by solid-state reaction method using Na2CO3 as flux and characterized by powder X-ray diffractometry. According to X-ray diffraction, this material belonged to a tetragonal system with space group I41/α. The effects of flux content and sintering temperature on the luminescent properties were investigated with the emission and excitation spectra. The results showed that flux content and sintering temperature had effects on the luminescent properties, the optimized flux content and the best temperature was 3 % and 800 ℃ respectively. The excitation and emission spectra also showed that this phosphor could be effectively excited by C-T band （280 nm）, ultraviolet light 395 nm and blue light 465 nm. The wavelengths at 395 and 465 nm were nicely fitting in with the widely applied output wavelengths of ultraviolet or blue LED chips. Integrated emission intensity of Gd2Mo3O9 ： Eu was twice higher than that of Y2O2S ： Eu^3 ＋ under 395 nm excitation. The Eu^3＋ doped Gd2Mo309 phosphor may be a better candidate in solid-state lighting applications.     

KCaM（PO4）2:Dy3+（M=La,Y,Lu）荧光粉的制备与发光性质

采用传统高温固相法制备了KCaM(PO4)2:Dy3+(M=La,Y,Lu)荧光粉。X射线衍射表明,KCaM(PO4)2:Dy3+(M=La,Y,Lu)荧光粉属于六方晶系,P6222空间点群;随着金属阳离子M离子半径的增大,衍射峰向小角度方向移动。低温下的KCaM(PO4)2:Dy3+(M=La,Y,Lu)荧光光谱表明:同一基质中Dy3+在不同波长光激发下,发射峰发生了改变。金属阳离子M在晶体中存在2种格位(发光中心),在不同金属阳离子M的基质中,用相同光激发时,发射光谱明显不同。金属阳离子M的改变引起周围晶体场的改变,从而改变2种格位在不同基质中所占有的比例。因此,可以把Dy3+作为探针来研究晶体结构的变化。     

Sr_5Si_2O_7Cl_4:Eu~(2+)材料的发光特性

采用高温固相法合成Sr5Si2O7Cl4:Eu2+材料。在370nm激发下,Sr5Si2O7Cl4:Eu2+材料呈现峰值位于490nm的非对称发射,对其进行Gaussian曲线拟合,得到峰值位于485nm和520nm两个明显的发射峰。利用van Uitert公式讨论Eu2+在基质中的晶格环境和发光特性,确定晶体中有蓝和黄绿两种发光中心:485nm发射来源于七配位的Eu2+中心发射;520nm长波发射与杂质束缚激子有关。进一步研究Sr5-xCaxSi2O7Cl4:Eu2+材料的发光性质,当0x0.5,Ca2+固溶于Sr5Si2O7Cl4基质晶格,Eu2+占据七配位Sr2+格位,晶体主要产生蓝色中心的蓝绿色发射;当0.5x2,Ca2+掺量增加使晶胞参数变小,晶格中的杂质束缚激子态的束缚增强,Eu2+处于杂质束缚激子中心所形成的激发态能量进一步降低,发射位于长波段,Sr5-xCaxSi2O7Cl4:Eu2+主要产生黄绿色中心的黄绿色发射。     

Luminescence characteristics of LiCaBO_3:Tb~(3+) phosphor for white LEDs

A novel green phosphor,LiCaBO3:Tb3+,was synthesized by solid state reaction method,its luminescence characteristics were investigated,and the formation of phosphors were confirmed by X-ray powder diffraction(XRD).Its excitation band extended from 220 to 400 nm,which was coupled well with the emission of UV LED(350-410 nm).It exhibited a strong green emission located at 544 nm with chromatic coordination(0.25,0.58).The emission intensities of LiCaBO3:Tb3+ phosphor were influenced by varying Tb3+ concentratio...     

Ca_2SiO_3Cl_2∶Eu~(3+)材料的发光特性

采用高温固相法合成了Ca2SiO3Cl2∶Eu3+红色发光材料。利用X射线分析了材料的晶体结构,其为四方晶系;在400nm近紫外光激发下,材料呈红色发射,主发射峰位于582、599、623、655和691nm,分别对应Eu3+的5D0→7F0、7F1、7F2、7F3和7F4特征跃迁;监测599nm最强发射峰,激发光谱覆盖200～450nm,主激发峰位于400nm。研究了Eu3+摩尔浓度对Ca2SiO3Cl2∶Eu3+材料发射强度的影响,结果显示,随Eu3+浓度的增大,强度先增大、后减小,Eu3+浓度为1%时,强度最大。引入Li+后,材料的发射强度进一步增大。     

Investigation of Modification Effect of B2O3 Component on Optical Spectroscopy of Er^3＋ Doped Tellurite Glasses

To investigate the modification effect of the B2O3 component on tellurite glass, a series of glasses with a composition of xB2O3-（80-x）TeO2-10ZnO-10Na20 （x = 0, 10, 20, 30, 40, 50, 60, 70, 80） and an additional amount of 0.5% Er2Os（in molar） were prepared. The refractive index, the absorption edge of the host, the J-O parameters of Er^3＋ , the fluorescent decay time, the bandwidth, and the quantum efficiency for the 4Ⅰ13/2→4Ⅰ15/2 transition were obtained theoretically and experimentally. These results indicated that the introduction of B2O3 modified the performance of the tellurite glass. For example, with increasing content of B2O3, the refractive index of the host decreases from 1.9 to 1.5, the absorption edge of the host shifted toward the blue regime, the intensity parameter Ω6 changed from 1.08 × 10^-20（for the pure tellurite glass） to 1.98 ×10^-20 cm^2（for the pure borate glass）, the bandwidth of the 4Ⅰ13/2→4Ⅰ15/2 transition increased, and the quantum efficiency of the 4Ⅰ13/2→4Ⅰ15/2 transition decreased.     

基于Modbus协议的CAN总线转换器设计

针对CAN现场总线和Modbus协议的特点，给出一种应用单片机技术设计CAN现场总线与Modbus总线的转换器的方法。实现了将Modbus设备连接到CAN现场总线网络中，并具体的介绍了转换器硬件结构和相应的软件程序流程，实际应用效果良好。     

基于CAN总线的污水溶氧量监控系统设计

曝气控制是污水处理过程中的关键环节，文中分析了曝气控制的基本原理，提出了以溶氧量为控制参数，设计了一套污水溶氧量监控系统。将CAN现场总线和变频器应用在监控系统中，给出了具体的设计思想与实现方法。在实际应用中该方法取得了良好的效果。