38MnVS6钢中硫元素扩散对激光熔覆涂层形貌和组织的影响

利用激光熔覆技术在38MnVS6钢基体上熔覆了CoCrW粉末,研究了不同扫描速度下基体中活性元素对涂层形貌和组织的影响。结果表明,当送粉速率为5.60g·min~(-1),扫描速度小于5mm·s~(-1)时,涂层的熔深较大,涂层与基体的结合线向下凹陷;当扫描速度大于6mm·s~(-1)时,涂层的熔深较小,涂层与基体的结合平整光滑。送粉率的增大使得涂层的形貌发生变化。基体中硫元素的含量决定了涂层表面张力温度系数,改变了熔池中马兰戈尼对流方向,并最终影响涂层的成分和组织。     

放射形土壤杆菌Q9415发酵生产胞外多糖的研究

本文对放射形土壤杆菌Q9415发酵生产胞外多糖的工艺条件进行了研究。研究表明,种龄为20h的种子液按8％—10％接种量对发酵产糖更为有利。分步法流加碳源和添加表面活性剂能明显提高产糖量。     

Luminescence Properties of (Y, Gd)Al_3(BO_3)_4∶Eu ~(3 ) under VUV excitation

Thephosphorsasanimportantpartofplasmadis playpanel (PDP)deviceemitvisiblelightundervac uumultraviolet (VUV)excitationof 14 7nmand/or172nmfromXe/Hegasplasma[1] .Untilrecently ,Y2 O3∶Eu3 and (Y ,Gd)BO3∶Eu3 havebeenusedascommercialred emittingphosphorsforPDP[2 - 3] .Butthesematerialsstillhaveshortcomingstobeim proved :lowlightoutputofY2 O3∶Eu3 uponVUVex citationandbadcolorpurityof (Y ,Gd )BO3∶Eu3 [4～ 5] .AluminoborateshavestrongabsorptionintheVUVregion ,andexhibitexcellentma…     

超临界流体萃取在食品工业中的应用

本文简要介绍了超临界二氧化碳萃取技术,概括了近十年来它在食品工业中的应用和最新研究动态,并对超临界二氧化碳萃取技术作了展望。关键词 超临界流体 萃取 食品工业     

高凝胶性能沙菜卡拉胶碱处理工艺的研究

采用 KOH溶液对沙菜进行高温稀碱法处理 ,通过正交实验方法得出了生产高凝胶性能卡拉胶的最佳碱处理工艺 ,所得卡拉胶的凝胶强度达到 80 0 g/cm2 ,产率超过 2 5%。该碱处理工艺具有工艺条件简单、生产周期短、环境污染少、碱液可循环利用等优点。     

Preparation and Luminescence Properties of the New Long Phosphorescent Phosphors Ba1-xCaxAl2O4∶Eu2+,Dy3+

New long phosphorescent phosphors Ba1-xCaxAl2O4∶Eu2 , Dy3 with tunable color emission were prepared and studied. The emission spectra show that the tuning range of the color emission of the phosphors is between 498 and 440 nm, which is dependent on x, under the excitation of UV. The wavelength of the afterglow increases with the increasing of x until x equals 0.6. The XRD patterns show that the single phase limit in the phosphors is below x value of 0.4. The Thermoluminescence spectra were measured to investigate the traps created by the doping of Dy3 .     

Luminescence Properties of(Y,Gd)Al3(BO3)4∶Eu3+ under VUV excitation

(Y, Gd)Al3(BO3)4∶Eu3 samples were prepared by the conventional solid state reaction. The XRD results indicate that the crystal symmetry is low. The excitation spectrum is composed of two broad bands centered at about 170 and 250 nm respectively. In the emission spectra, the peak wavelength is about 616 nm under 147 nm VUV excitation. The luminescent chromaticity coordinate and the relative intensity change along with Gd3 mole concentration in the range of 0.15 to 0.85 mol(and Eu3 mole concentration, 0.02 to 0.1 mol). The correlative data show that the concentration quenching occurs when the Eu3 mole concentration ranges from 0.02 to 0.1 mol, and the Gd3 →Gd3 , Gd3 →Eu3 and host→Eu3 , Gd3 energy transfers exist, and Gd3 mole concentration influences Eu3 emission.     

浅谈建筑电气设计与施工技巧

随着科技的发展,时代的进步,现代建筑的功能逐渐迈向多样化,建筑电气的重要性也日益明显。现代电子产业的发展和大规模智能化建筑的兴起,建筑电气设计中所涉及的各类管线将越来越多,对防雷、防电磁脉冲等保护措施的要求也越来越高,因此作为设备设计中的一部分,建筑电气设计与其他专业特别是与结构专业之间的协调、配合应该得到相应的重视。本文介绍了如何使建筑电气和建筑结构二者相协调,提出了一些针对其特点的设计和施工方法。