抗菌、耐酸碱腐蚀聚丙烯的研究

题名:抗菌、耐酸碱腐蚀聚丙烯的研究
作者:陈旭
学位授予单位:河北工业大学
关键词:聚丙烯;;稀土β成核剂;;抗菌剂;;耐酸碱;;力学性能;;结晶性能
摘要:

 本论文研究了抗菌聚丙烯及耐酸碱腐蚀聚丙烯的制备。通过测试在不同类型改性剂和配比下材料的抗菌性和耐酸碱腐蚀性,确定最佳的选料配比,并对改性材料的力学性能和结晶性能作了探讨。

 抗菌材料选用无机金属离子/纳米二氧化钛抗菌剂(Ag+-TiO_2抗菌剂)和有机季铵盐抗菌剂(CTAB)作为抗菌改性剂,对稀土β晶成核剂(WBGⅡ)改性的无规共聚聚丙烯材料进行抗菌研究。结果表明,对无机抗菌剂进行适当的表面处理可以有效的提高抗菌剂与基体PPR的相容性;Ag+-TiO_2抗菌剂的抗菌能力要优于所Strong magnets选取的有机季铵盐抗菌剂,其对大肠杆菌、金黄色葡萄球菌的抗菌率分别达到93.8%～99.2%、91.7%～98.2%;而CTAB抗菌剂对大肠杆菌、金黄色葡萄球菌的最佳抗菌率分别达到91.0%、91.4%。同时发现,Ag+-TiO_2抗菌剂一定程度上降低了材料的韧性。在等温结晶过程中,抗菌剂Ag+-TiO_2的加入抑制了WBGⅡ对PPR基体β晶晶型的诱导,而有机抗菌剂CTAB的加入改变了PPR体系的结晶速率,使晶球形态发生变化。加入抗菌剂Ag+-TiO_2和CTAB均可以有效的提升改性材料的熔融和结晶温度,降低材料结晶成核时的过冷度。

 耐酸碱腐蚀性材料选用无机纳米氧化硅和纳米氧化铝复合式改性剂,对WBGⅡ改性的无规共聚聚丙烯改性材料进行耐酸碱腐蚀性研究。结果表明,Al_2O_3/SiO_2/PPR改性材料和WBGⅡ/Al_2O_3/SiO_2/PPR改性材http://www.chinamagnets.biz/料相比于纯PPR,耐酸碱性能都得到了提高。并且,加入Al_2O_3/SiO_2和WBGⅡ改善了材料的加工性能,WBGⅡ的加入细化了晶粒,但由于Al_2O_3/SiO_2在一定程度上抑制了WBGⅡ成核能力,使结晶速率减慢。得到了使改性材料获得最佳耐酸碱性能、力学性能和加工性能等综合性能的配方:WBGⅡ/Al_2O_3/SiO_2/PPR:0.3/1.4/0.6/100。
学位年度:2010

北大巴山志留系火山碎屑岩序列与成因环境研究

题名:北大巴山志留系火山碎屑岩序列与成因环境研究
作者:向忠金
学位授予单位:中国地质科学院
关键词:火山碎屑岩;;碱性玄武岩;;滔河口组;;北大巴山
摘要:

 北大巴山志留系滔河口组为一套以火山碎屑岩为主、夹碱性玄武岩和海相沉积岩的火山—沉积地层,一系列规模不一的辉绿岩脉侵入地层中。本文通过系统的1/10,000地质填图、大比例尺实测剖面和地球化学分析工作,对滔河口组的相序组合、火山—沉积序列及火山活动的岩浆源区及构造环境进行了研究。

 滔河口组火山—沉积序列包含共生相、原生火山碎屑岩相、同喷发火山碎屑岩相、含火山碎屑沉积岩相和正常沉积岩相5个相组合、22种不同岩相。自下而上由玄武岩(一般下部为粗粒/细粒玄武岩、上部为枕状或杏仁构造玄武岩)、凝灰角砾岩(局部为再沉积富辉石火山砾岩)、无结构(或叠瓦状)凝灰质粗砾岩、凝灰质rare earth magnets砂岩、生物灰岩或泥岩等岩相构成。具有下部为玄武岩,上部为火山碎屑岩(碎屑流沉积)或碳酸盐岩的“二元”结构特征,与洋岛/海山相似。区域地质填图表明,滔河口组火山活动具有西强东弱的特征,可能受断裂控制,具裂隙式喷发特征。根据火山碎屑岩组成和沉积特征,推测古火山活动以夏威夷—斯托柏林型(Hawiian-Strombolian type)喷发为主,在初始阶段可能存在舒尔特赛型(Surtseyan)喷发。

 地球化学分析表明,碱性玄武岩中辉石斑晶主要为次透—透辉石,少量为深绿辉石。普遍富集LREE,轻重稀土强烈分异。不同岩相玄武岩中辉石主量元素含量呈连续线性变化,REE和微量元素标准化配分曲线大致平行,表明它们是同一岩浆连续结晶分离的产物。滔河口组碱性玄武岩的岩浆源区为富不相容元素流体交代的,由HIMU、EMII和EMI三个端元混合而成的复杂地幔源区。

 根据单斜辉石—熔体平衡温压http://www.chinamagnets.biz/计算方程,计算获得辉石斑晶三组结晶温度和压力,分别为1246-1324℃,1.13-2.05 Gpa; 1200-1211℃,0.44-0.62 Gpa; 1159-1183℃,0.14-0.28 GPa。结晶压力差异表明岩浆在上升过程中分别在37-68 km、15-20 km和5-9 km三个深度发生了储积结晶。随着岩浆的上升演化,辉石具有镁降低、钙和铁升高,碱性玄武岩具有基性降低、逐渐富硅、碱质和挥发分的变化规律。

 火山—沉积地层序列、辉石斑晶和碱性玄武岩的地球化学特征等综合表明,滔河口组形成于被动大陆边缘环境。
学位年度:2010

氮化硅基连续功能梯度材料的制备及其性能研究

题名:氮化硅基连续功能梯度材料的制备及其性能研究
作者:刘强
学位授予单位:哈尔滨工业大学
关键词:氮化硅基材料;;连续功能梯度材料;;放电等离子烧结;;稀土氧化物;;BaSi_2Al_2O_8(BAS)
摘要:

 功能梯度材料具有同时满足不同使用要求、提高材料的使用可靠性的优点。但采用传统制备方法获得的梯度材料在材料内部沿梯度方向上很难避免产生应力,特别是采用层叠法制备的梯度材料,不同的层之间存在成分突变Neodymium magnets的界面导致产生较大的内应力;而且一般方法较为繁琐,难以控制制备过程。本文以混合均匀的原始粉体为原料,采用放电等离子烧结技术,合理设计烧结模具放置方式,产生了连续梯度变化的温度场,烧结制备了不同组成成分的氮化硅基连续功能梯度材料,消除了梯度材料内部产生的应力。研究了所制备的连续梯度材料的相组成、力学性能和显微组织的变化;并研究了不同添加剂或材料组分对材料力学性能和显微组织的影响。

 将放电等离子烧结过程中的模具采用不对称放置,使模具上下两端与放电等离子烧结炉中电极接触面积不同,可以造成模具两端的电流密度差异较大,实现在模具中产生稳定的温度梯度场。采用混合均匀的添加20wt% BaSi_2Al_2O_8(BAS)的氮化硅复合粉末制备了BAS/Si_3N_4连续功能梯度材料,材料中β-Si_3N_4相对含量随着距离低温端的距离增大而增大。从低温端β-Si_3N_4相对含量为12%变化到高温端β-Si_3N_4相对含量为83%;材料的硬度随着离低温端距离的增大而减小,由低温端的16.7GPa降低到高温端的的12.6GPa,而断裂韧性值则从低温端的3.22 MPa·m1/2增大到高温端的5.72MPa·m1/2。制备的梯度材料由低温端中大量等轴状的细小晶粒逐渐变化到高温端中较大尺寸的长棒状晶粒。

 以不同稀土氧化物和MgO作为复合烧结助剂制备了(RE_2O_3+MgO)/Si_3N_4连续梯度材料。材料从低温端到高温端的维氏硬度从最高约为20GPa降低到最低约为15GPa,而高温端面断裂韧性最高达7.12MPa·m1/2,低http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php
温面最低断裂韧性为5.30 MPa·m1/2。在材料低温端具有大量细小的等轴状晶粒,在沿厚度方向上,随着离低温端距离的增大,等轴状晶粒逐渐减少,转变成长棒状的晶粒,并且长棒状晶粒尺寸逐渐增大;添加Lu2O3比添加Gd2O3更容易促进α-Si_3N_4→β-Si_3N_4的相转变,且获得直径较大的长棒状晶粒,而添加Gd2O3更容易获得具有较高长径比的长棒状晶粒;在β-Si_3N_4相的相对含量较少的截面上,摩擦系数和摩擦磨损率都较小。

 以均匀的原始粉体为原料,采用SPS烧结制备了SiC/Si_3N_4复合连续梯度材料。结果表明从材料的低温端到高温端存在相组成成分、维氏硬度和断裂韧性、

 以及显微组织连续梯度变化。α-SiC的存在给β-Si_3N_4相的生成提供了大量形核位置,但对已形核的β-Si_3N_4晶粒晶界推移起抑制作用,使SiC/Si_3N_4复合连续梯度材料获得许多细小的长棒状β-Si_3N_4晶粒。
学位年度:2010

晶圆清洗机无刷电机及其控制策略研究

题名:晶圆清洗机无刷电机及其控制策略研究
作者:戈小中
学位授予单位:湖北工业大学
关键词:晶圆清洗机;;无刷电机;;控制策略;;转矩脉动;;试验
摘要:

 晶圆清洗作业对无尘工作环境和清洗设备都有很高的要求。目前晶圆清洗机采用直流伺服电动机作为驱动电机,但碳刷的磨损给无尘工作环境带来了污染,增加了维护成本。稀土永磁无刷直流电动机取消了碳刷和换向器,可靠性高,免维护,高效率,是有刷直流电动机的理想替代电机。

 项目研究内容包括四个方面。首先,对集中绕组无刷电机相关理论问题进行研究,如分析表贴式无刷电机转子磁钢宽度与气隙磁密波形Neodymium magnets的关系,无刷电机无位置传感器检测位置方法—电感法,在此基础上试制出晶圆清洗机中空轴无刷电机；其次,在研究所已开发的通用无刷电机控制器基础上,设计并制作用于晶圆清洗机无刷电机控制器；再次,对晶圆清洗机无刷电机控制策略进行研究,然后进行软件开发和现场调试与试验；最后对方波无刷电机全速范围内的转矩脉动抑制进行研究,提出了低速、中速和高速的控制策略,然后软件设计和进行调试与试验。

 论文分为六章。第1章综述了晶圆清洗机驱动电机、无刷电机控制器以及其控制策略的发展现状,根据晶圆清洗机的生产工艺过程,介绍了对无刷电机驱动控制的要求；第2章分析了表贴式无刷电机转子磁钢宽度与气隙磁密波形的关系,研究了无刷电机无位置传感器检测位置方法—电感法,最后讨论了晶圆清洗机无刷电机的设计和工艺问题；第3章研究了基于DSP2407和三菱IPM的无刷电机控制器,介绍了整个控制器的硬件构成,详细说明了各个模块的功能及实现方法,给出了设计过程中出现的问题和解http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php决办法；第4章对晶圆清洗机的控制策略进行了研究,选择改进的双闭环控制策略,然后进行了该控制策略的软件设计,最后进行了仿真和现场试验；第5章对方波无刷电机全速范围内的转矩脉动抑制进行研究,提出低、中和高速相应控制策略,然后进行该控制策略的软件设计与现场调试与试验,给出了试验结果；第6章全文总结。
学位年度:2010

外转子混合励磁风力同步发电机研究

题名:外转子混合励磁风力同步发电机研究
作者:冯骥
学位授予单位:湖北工业大学
关键词:混合励磁;;风力同步发电机;;电磁设计;;仿真分析;;试验研究
摘要:

 风力发电已经成为世界上增长最快的新型能源。在过去的近半个世纪里,在各国政府的大力支持下,经过研究者的不懈努力,风电技术发展迅速,在技术水平、性价比以及装机容量等方面都取得了长足的进步,越来越多的大中型风电场相继建成并投入运行,为电网提供清洁能源。

 在风力发电领域,高效率的稀土永磁发电机已经引起人们关注。但是,永磁发电机也存在气隙磁场难以调节的问题,限制了它在大中型风力发电机中的应用。尽管国内外研究者提出了一些永磁发电机的调压和稳压方法,但大都技术复杂、成本高、实现难度大。近年来,混合励磁发电机令人瞩目,它可以实现宽范围Neodymium magnets的磁通调节,实时控制发电机的输出电压,扩展风力发电机发电的风速范围,提高风力发电效率。本文研究一种新型混合励磁外转风力同步发电机。这种发电机在内定子中增设了励磁绕组,通入直流电流就可以调节其气隙磁通,实现增磁或去磁；它不需要电刷或滑环,免维护,可靠性高。

 本文首先研究了不同型式的混合励磁电机,提出了外转子混合励磁风力同步发电机的拓扑结构,对这种新型发电机的运行原理和特性进行了理论研究；其次进行了三维磁场的建模与分析,并讨论了电磁设计方法；再次,建立了混合励磁风力同步发电机MATLAB仿真模型和系统仿真模型,进行了仿真分析；最后设计并试制了一台额定功率为200W、额定电压为110V、额定转速为600 r/min的风力同步发电机试验样机,构建了试验平台,对其进行一系列试验研究。试验结果表明,混合励磁风力同步http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php发电机输出电压波形好,电压调节能力强,完全能够满足高性能风力发电机的要求。在上述工作的基础上,论文还给出了一台额定电压为110V、额定功率为4kW混合励磁外转风力同步发电机设计方案。
学位年度:2010

Nd and reciprocating extrusion of Al_2O_ (3f) / AZ91D composites and high temperature creep

Title: Nd and reciprocating extrusion of Al_2O_ (3f) / AZ91D composites and high temperature creep behavior of Author: Mr Tung Chi-Joe Degree-granting units: Xi'an University of Technology Keywords: Al_2O_ (3f) / AZ91D composite materials;; microstructure;; Nd;; reciprocating extrusion;; high temperature creep Summary: In this paper, prepared by pressureless infiltration of Nd content of 0.0%, 0.2%, 0.5% and 0.8% of the Al2O3f/AZ91D composite (fiber volume fraction of 20%), and different Nd content of the composite materials were reciprocating extrusion. The use of OM (optical microscope), SEM (scanning electron microscopy), XRD (X-ray diffraction) and EDS (EDS) analysis and other detection methods, explore Nd and reciprocating extrusion of composite Neodymium Magnets microstructure, phase composition, hardness and high temperature creep properties. High temperature compression as a means to carry out Al2O3f/AZ91D high temperature creep properties of composite materials research, composite materials, creep through the curve and the creep stress index composite materials, and explore its mechanism of creep and creep process and to explore the high-temperature compression creep change the course of the evolution of microstructure and composite materials dynamic recrystallization mechanism. After the composite materials of Nd added to form a granular and rod-shaped Al-Nd phase, while Nd refine the matrix organization, and tend to make small dispersed Mg2Si phase; of Nd addition can significantly improve the hardness and high temperature composite materials creep, adding 0.8% Nd of Al2O3f/AZ91D composite hardness and resistance to high temperature creep properties of the best; added after the Mg2Si phase Nd hardness then decreased, the Nd content of 0.5% of maximum hardness. Al2O3f/AZ91D composite materials after two times of reciprocating extrusion, a significant refinement of the matrix organization, squeezed to eliminate the fiber segregation, improved fiber distribution; constant temperature (250 ℃) constant load (90MPa), the reciprocating extrusion pressure-state-cast composite materials than the high-temperature creep properties of composite materials has declined; reciprocating extrusion process reduces the hardness http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets of Mg2Si phase, but the hardness of composite materials has improved. After high temperature compression creep of fiber is more evenly distributed, and organizations to further refinement, the matrix deformation twins can be observed and cross-slip line, fiber segregation in the district the formation of recrystallized grains. Composite materials by studying Al2O3f/AZ91D 250 ℃ when the lnε-lnσ curve and fitting a straight line to get the stress exponent n is 6.6, the creep of composite materials by the lattice diffusion controlled dislocation creep model mechanism and sub-structure constant result of the role. According to the n-value mapping (εn-σ) / 1 curve, the composite material at 250 ℃ threshold stress is 1.32MPa. Degree Year: 2010

Preparation and properties of rare-earth silicate phosphor research

Title: Preparation and properties of rare-earth silicate phosphor research
Author: Chen Zhenmin
Degree-granting units: Beijing Jiaotong University
Keywords: portland;; a single matrix;; dysprosium ion;; europium ion;; solid state lighting;; white LED
Summary:
Silicate matrix has good chemical stability and thermal stability, a long time people have paid attention to the silicate matrix phosphor research and development. White phosphor matrix with a single lumen for high efficiency and good color reproduction characteristics, so the significance of their research.
In this paper, high-temperature solid-phase synthesis of M2SiO4: Dy3, Eu3 (M = Mg, Ca) series LED with a phosphor, and the structural characteristics Strong magnets of the sample and the corresponding near-UV excitation of the luminescence properties are studied.
Series of samples M2SiO4: Dy3, Eu3 (M = Mg, Ca) X-ray powder diffraction data with the JCPDS standard cards are in good agreement, suggesting that our synthetic material is alkaline earth metal silicate, silicate system is working.
In the spectrum of the phosphor doped Dy3 can see, the sample absorption at 325nm, 350nm, 365nm and 386nm near, corresponding to the Dy3 ion 6H15 / 2 → 6P3 / 2,6 H15 / 2 → 6P7 / 2,6 H15 / 2 → 6P5 / 2,6 H15 / 2 → 4M21 / 2 transitions. The use of 386nm UV excitation, located in 480nm, 492nm, 575nm emission near the peak corresponding to the Dy3 ion 4F9 / 2 → 6H15 / 2 transitions, 579nm corresponding to the Dy3 ion 4F9 / 2 → 6H13 / 2 emission transition.
Prepared Dy3, Eu3 doped samples, the spectrum of its shows a marked increase in red light district in addition to the orange emission light 590nm, red light 616nm, 653nm, 704nm at the launch, more than are the 5D0 → 7FJ Eu3 (J = 1,2,3,4) transition http://www.chinamagnets.biz/ emission energy levels. Adding rare earth ions Eu3 luminescence of samples corresponding to the color coordinates and color temperature greater impact.
Synthesis and analysis of the binary system samples of alkaline earth metal cations (MgxCa1-x) 2SiO4: Dy3, Eu3 UV spectral characteristics, the proportion of the alkaline-earth ions in different spectra and color coordinates of the impact.
Figure 23 in this paper, Table 8, reference 45.
Degree Year: 2010

Based on Zn (Ⅱ)-Ln (Ⅲ) asymmetric Schiff base complexes and light-induced near-infrared light-emitting electroluminescent device research

Title: Based on Zn (Ⅱ)-Ln (Ⅲ) asymmetric Schiff base complexes and light-induced near-infrared light-emitting electroluminescent device research Author: Wei Tao Degree-granting units: Northwestern University Keywords: asymmetric Schiff base;; df mixed metal compounds;; near-infrared light;; organic light-emitting diodes Summary: Rare earth ions (4f) near infrared (NIR) light-emitting characteristics of people in recent years on Yiqi wide attention, mainly because of its sensors, lasers, fiber-optic communications, bio-imaging has significant potential applications. In order to stimulate the Nd (Ⅲ), Er (Ⅲ), Yb (Ⅲ) and other lanthanide ions in near-infrared light, to overcome the lanthanide ions rare earth magnets parity forbidden ff transitions, a variety of antennas have been designed to sensitive groups characteristics of its light. In this paper the use of Zn (Ⅱ) asymmetric Schiff base compounds as sensitizing chromophores to near-infrared luminescence of rare earth ions, synthesis of 24 new Zn-Ln two multi-core compounds, and systematic study of its light-induced luminescence properties; and use the compounds screened as a near-infrared light-emitting diode (OLED) light-emitting layer host material, a preliminary study of its electroluminescent properties. First of all, with methyl - ethylenediamine and o-vanillin Schiff base asymmetric reaction (H2L1), to H2L1 of Zn (Ⅱ) compounds [ZnL'Py] (1) as the precursor synthesized Zn-Ln Series two nuclear compound [Zn (L1) Ln (N03) 3Py] (Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4; Ln = Gd, 5), the series of compounds to determine the molecular structure of , and studied the laws of energy transfer; while the heavy atom Br has been introduced into H2L1 H2L2, synthesized on this basis, there is heavy atom effect of Zn-Ln series two nuclear compound [Zn (L2) Ln (N03) 3Py] (Ln = Nd, 7; Ln = Yb, 8; Ln = Er, 9; Ln = Gd, 10), and determine its molecular structure and photophysical properties. Second, with 3 - benzoyl-- o-phenylenediamine and o-bromo-o-vanillin or vanillin reaction has been two asymmetric Schiff base H2L3 and H2L4, respectively, Zn (Ⅱ) complexes [ZnL3Py] ( 11) and [ZnL4Py] (16) as the precursor, synthesized Zn-Ln series of complexes (compounds Ln = Nd, 12; Ln = Yb, 13; Ln = Er, 14; Ln = Gd, 15; compounds Ln = Nd, 17; Ln = Yb, 18; Ln = Er, 19; Ln = Gd, 20), means the use of spectroscopy for H2L3 and H2L4 of Zn (II)-Ln (III) complex structure analysis to determine the their structure and studied its photophysical http://www.chinamagnets.biz/ properties. Third, based on the above thinking, with 3 - hydroxy - o-phenylenediamine and get the other two ligands H3L5 and H3L6, "one-pot" direct synthesis of both zinc - pyridine compounds [ZnHL5Py] (21) and [ZnHL6Py ] (22), synthesized as a precursor to their Zn-Ln complexes [Zn2 (L5) Ln2 (N03) 4 (Py) 2 (DMF) 2] (Ln = Nd, 23; Ln = Yb, 24; Ln = Er, 25; Ln = Gd, 26) and [Zn2 (L6) Ln2 (N03) 4 (DMF) 4] (Ln = Nd, 27; Ln = Yb, 28; Ln = Er, 29; Ln = Gd , 30), and determine its molecular structure, electronic absorption spectra, emission spectra, quantum yield and fluorescence lifetime and the antenna group of the rare earth ion energy transfer rate constant, and studied the system of heavy atom and the pyridine compound infrared light-emitting properties. Fourth, the above series of compounds selected from the representative compounds [Zn (L2) Yb (NO3) 3Py] (8) light-emitting layer doped with CuPc as the main material of infrared light-emitting devices. Device structure is ITO / TPD (40 nm) / CuPc (x%, x = 0,5,10,15): 8 (30 nm) / TPBI / LiF: Al (1:150 nm), EL position λem = 980 nm, show that these compounds in the near-infrared organic light-emitting diode has potential applications. Degree Year: 2010

β-diketone ligand and its Synthesis, Structure and Properties of

Title: β-diketone ligand and its Synthesis, Structure and Properties ofAuthor: Hui YuanyuanDegree-granting units: Northwestern UniversityKeywords: β-dione;; different metal complexes;; magnetic properties;; UV - visible spectrumSummary:In recent years, with the special nature of the new molecular materials research is very active, such as molecules and molecular materials, optical materials, superconductivity, and some have even entered the application phase. β-diketone compounds in magnetic materials, optics, catalysis, gas storage, fluorescent materials, the device has potential applications. In addition, the design and synthesis of such compounds, structure and properties in coordination chemistry, rare earth magnets crystal engineering and materials science research in the field has gradually become a research hotspot. Therefore, this article contains a β-diketone-based synthesis of symmetric and asymmetric bipolar base ligand idea, successful synthesis of three β-diketone ligand and its thirteen complexes, and structural characteristics of complexes , the nature of the study.This paper consists of the following three parts:First, this synthetic ligand symmetric and asymmetric bipolar idea as the guiding ideology, the one kind of asymmetric synthesis of β-diketone ligand: 2 - (3 - phenyl-1 ,3 - dione C base) - 6-- pyridinecarboxylic acid (H2L1), 2 种 symmetrical β-diketone ligand: 2,6 - bis (3 - phenyl-1 ,3 - dione C) pyridine (H2L2) and 2,6 - bis (3- - thienyl-1 ,3 - dione C) pyridine (H2L3). By IR, UV-vis, 1HNMR ligand compounds were characterized.Second, the use of crystal engineering method, the ligand H2L1 and transition metal and rare earth, and build the four metal-organic complexes. Three complexes 1: [Ni3 (Ll) 2 (OAc) 2 (DMF) 2 (H2O) 2] · DMF · H2O (1), four complexes 2: [Ni4 (L1) 4 (DMF ) (H2O) 3] · 2.5DMF · 3H2O (2) and [Ni4 (L1) 4 (H2O) 4] · 10 (H2O) (3). Binuclear lanthanide complexes 1: [Yb2 (Ll) 2 (NO3) 2 (H2O) 2] 2-2 (C2H5OH) · 2 (H2O) (4). Complexes also studied the http://www.chinamagnets.biz/ magnetic properties of 1 and 2, to discuss the magnetic properties and the relationship between the compounds.Three diffusion method using ether to ligand H2L2, H2L3 and metal out of the three different synthetic metal complexes: transition - alkaline earth complexes [Co2Ca (L2) 2 (OAc) 2 (H2O) 4] · 2DMF (5) , [Co2Ca (L2) 2 (OAc) 2 (CH3OH) 4] (6) and [Ni2Ba (L2) 2 (DMF) 2 (H2O) 2Cl2]-2DMF (7); transition - transition complexes [Co2Pb ( L2) 2 (OAc) 2 (CH3OH) 4] (8) and [Ni2Pb (L2) 2 (OAc) 2 (CH3OH) 4] (9). Transition - rare earth complexes [Co2Ln (L3) 2 (OAc) 3 (CH3OH) 2] [Ln = Eu (10), Pr (11), Nd (12), La (13)]. Also the major complexes 10 and 13 of the magnetic properties were studied, in addition to the complexes 5-13 do UV - visible spectral properties.Degree Year: 2010

Rare earth luminescent materials, nano-structured SiO_2 Preparation and Properties

Title: Rare earth luminescent materials, nano-structured SiO_2 Preparation and Properties Author: Jing Pan Degree-granting units: Northwestern University Keywords: sol-gel method;; rare-earth-doped SiO_2;; emission spectra;; metal ions;; core-shell structure Summary: In this paper, the sol - gel method and hydrothermal method with different types and different structures of doped nano-Si02-emitting material by fluorescence (PL) spectra, infrared absorption spectroscopy (IR), atomic force microscopy (AFM), transmission electron microscopy (TEM ) and other modern means of analysis of samples were characterized, and its luminescence mechanism is analyzed. By studying the different water content, annealing temperature on the fluorescence intensity, luminescence intensity and phosphorescence lifetime and other properties, that either powder or film form for Tb3 +-doped SiO2-emitting materials, these factors also affect the luminescence of Tb3 + performance, and the luminous intensity of the impact of the formation rare earth magnets of a competitive mechanism. The sample annealed at 750 ℃ ​​luminous intensity, with the water content increases, the first increase and later decrease after decrease. By analyzing samples of the phosphorescence properties, that the water content of the phosphorescence and fluorescence intensity of the same trend, and luminescence decay time of significant impact. Finally, to determine TEOS, ethanol and distilled water, the optimal molar ratio of 1:4:4, aging time of the day, there is an optimal annealing at 650-800 ℃ temperature makes the sample SiO2: Re3 + light most . Using sol-gel method were prepared by Zn2 +, Sn2 + and Al3 + and other metal ions doped SiO2: Re3 + light dry gel and film, films were deposited on glass and silicon. Full use of F-7000 fluorescence spectrometer analysis of different metal ions doped SiO2: Re3 + luminescence properties of samples. By changing the rare earth ion doped metal ions makes the micro-environment samples SiO2: Re3 +, Mn + luminous efficiency increases. Under the same conditions, the most luminous powder, glass-plated luminous intensity of the film, followed by plating on silicon thin-film light-emitting weakest. As the local field enhancement or energy transfer effects, the metal ion-doped SiO2: Re3 +-doped sample is less strong light; metal ion-doped samples required for optimal annealing temperature than non-doped sample is reduced; different types of metal ion-doped SiO2: Re3 + samples corresponding to the strongest light the optimum concentration of different, such as when Re is the time Tb, Zn2 + doping of the best concentration of 0.4%, while the Sn2 + 0.2%. In addition, comparing the use of hydrothermal and sol-gel method has been SiO2: Tb3 +, Zn2 + luminescence properties of samples, the http://www.chinamagnets.biz/ samples found to be using the former as the latter's strong light, mainly due to the formation of the matrix network structure is different. Sol-gel method using core-shell structures were prepared SiO2: Tb3 + coated SiO2 particles (Si @ Si-Tb) and SiO2-coated SiO2: Tb3 + particles (Si-Tb @ Si) two structures, nano-materials by changing structure makes the luminous efficiency of the sample increases. Under certain conditions, core-shell structure of the luminous intensity than the Powder SiO2: Tb3 + strong, and come to 0.8 Si @ Si-Tb-z sample highest luminous efficiency, nuclear mass 0.8g of SiO2 particles dispersed in 25ml of SiO2: Tb3 + solution, the sample obtained without aging high luminous efficiency. With the nuclear mass increases, the light also increased the number of ions, luminescence enhancement, but to a certain value, the light diminished. By analyzing the clear solution obtained after filtration and precipitation of light-emitting properties of the samples and found that the supernatant from the lower precipitation than the product of luminous intensity, and has nothing to do with the nuclear mass or structure. Degree Year: 2010

Er on the A356 alloy semi-solid cast

Title: Er on the A356 alloy semi-solid cast and the metamorphism of Author: Zheng Xuebin Degree-granting units: Beijing University Keywords: Er;; A356 alloy;; semi-solid;; deterioration Summary: Semi-solid forming (SSM) is superior to conventional liquid-solid metal forming and metal forming of near net shape technology. Hypoeutectic Al-Si alloy in the primary α-Al phase and the eutectic silicon phase determines the size and morphology of semi-solid forming parts of the final performance. In this paper, optical microscope, quantitative metallographic analysis, X-ray diffraction, thermal analysis, scanning electron microscopy and transmission electron microscopy and other analytical tools for study of rare earth Er A356 hypoeutectic Al-Si alloy semi-solid cast and metamorphism, the results show that: Er-cast A356 alloy can reduce the secondary Neodymium magnets dendrite arm spacing (DAS), grain refinement of cast, so that tends to equiaxed dendrite oriented. Increase of Er added heterogeneous nucleation, the semi-solid structure of primary α-Al phase percentage increases, increasing the α-Al phase solidification range, broadening the temperature range of two-phase region, lower semi-solid slurry preparation the temperature requirements, saving the cost of process control. Morphology of eutectic silicon phase change can improve the mobility of semi-solid slurry. Er eutectic silicon phase of a significant modification effect, add 0.3% of Er can make the eutectic silicon sheet by the thick needle into a small fibrous. Deterioration of Er has a critical cooling rate, the modification effect of cooling rate increases with the increase. As the Er can significantly reduce the total crystal nucleation and growth of the temperature, increase the eutectic recalescence temperature, nucleation difficult to make silicon eutectic Al grains prior to the nucleation of eutectic silicon, silicon eutectic phase Al was forced to only between grain nucleation, and thus the formation of fibrous forms. Control by adding rare earth Er grain nucleation and growth, can be prepared with a small, round ball of semi-solid slurry particles, slurry solid fraction in between 0 to 0.45. Semi-solid roundness of primary phase content increases with increasing Er, Er content increases to 0.5% of the roundness of the primary phase reaches its maximum value. Er solidification of the remaining liquid produced by the second primary α2-Al phase also has a great influence, to make http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php primary α2-Al phase from the dendrites into small spherical crystal. Add 0.3% of the tensile properties of Er significantly improved, but continue to increase the content of Er, Er-rich alloy phase appears mainly to needle-like morphology and the massive presence of the alloys have an adverse effect. Therefore, the optimal dosage of 0.3% rare-earth Er. ALLOY system for the study found that in 180oC time 6h alloy for maximum hardness. Alloy in the aging process of strengthening the role of the still from the strengthening phase Mg2Si, Al-Er intermetallic compounds in the process increase the strength of the alloy is not. Degree Year: 2010

New Nd ~ (3 +) doped inorganic near-infrared light-emitting materials, preparation and luminescent properties

Title: New Nd ~ (3 +) doped inorganic near-infrared light-emitting materials, preparation and luminescent properties Author: Wan Chui Ming Degree-granting unit: Jinan University Keywords: near-infrared light;; energy transfer;; phosphor;; Ca_2BO_3Cl;; alkaline earth chloride silicate;; compound phosphate Summary: Nd3 +-doped rare-earth near-infrared light with a large penetration depth, line width, background and other characteristics, such as markers in biological analysis has important application prospect. The major bottleneck in the application of its relatively weak near-infrared light intensity. By sensitized Nd3 + ions and energy transfer between near-infrared light to Neodymium magnets increase its strength in important ways. Eu2 + has the 4f → 5d electric dipole allowed transitions, can efficiently absorb the excitation light energy, and may transfer energy to the Nd3 + ion and sensitized luminescence. This commitment to research Eu2 + sensitization of new and efficient near-infrared Nd3 +-doped Eu2 + luminescent materials and to explore the near-infrared luminescence of Nd3 + energy transfer mechanism. Specific experiments are: High temperature solid phase prepared Ca2BO3Cl: Eu2 +, Nd3 + near-infrared light-emitting materials, the results show, Eu2 + incorporation can improve the Nd3 + near-infrared light intensity, Eu2 +, Nd3 + doping amount were 0.03,0.05, the near-infrared light the strongest. Proof of Eu2 + by non-radiation energy transfer to Nd3 + to effectively transfer the energy of the near-infrared Nd3 + have a good sensitization. High temperature solid phase prepared Ca3SiO4Cl2: Eu2 +, Nd3 +, Ca8Mg (SiO4) 4Cl2: Eu2 +, Nd3 + luminescence materials found Eu2 + on the near-infrared light-emitting Nd3 + exists sensitization. Studied the Eu2 +, Nd3 + doping concentration on the near-infrared luminescence properties and the variation of relative intensity. Examined the calcination temperature, calcination time on the near-infrared light-emitting properties. In Ca8Mg (SiO4) 4Cl2: Eu2 +, Nd3 + system, the sample of near-infrared emission intensity of Eu2 + doped with increasing concentration of the first enhanced and then decreased, Eu2 + doping amount of 0.08, the strongest near-infrared light; Nd3 + doping concentration of 0.10, the strongest near-infrared light. Sample calcination temperature of 1100 ℃ in the calcined 3h, the strongest near-infrared light. Analysis of the Eu2 + and Nd3 + between the energy transfer mechanism: Eu2 + with 4f → 5d transition track, can effectively absorb the energy, and http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php energy transfer to Nd3 + energy levels, the occurrence of energy transfer, enhanced Nd3 + near-infrared light. High temperature solid phase prepared Sr4Si3O8Cl4: 0.08Eu2 +, 0.08Nd3 + light-emitting materials and found that the system of Eu2 + to the Nd3 + near-infrared light exists sensitization, near-infrared luminescence intensity increased by 10 times, Eu2 + to Nd3 + energy transfer efficiency of 19.7%. Studied the Ca, Mg-doped Sr4Si3O8Cl4: 0.08Eu2 +, 0.08Nd3 + series light-emitting materials, with the Ca content increases, the sample of near-infrared light show a gradual increase trend. Samples of near-infrared luminescence intensity increased with the Mg content showed a gradual weakening of the trend. Prepared by solid-phase LiSrPO4: Eu2 +, LiCaPO4: Eu2 +, KCaPO4: Eu2 +, NaCaPO4: Eu2 + series of highly efficient blue, green phosphor, the phosphor to optimize the preparation conditions. Among them, studies have shown that LiSrPO4: Eu2 + doping amount of change as there are different luminescence centers; LiCaPO4: Eu2 + is a new and efficient blue phosphor; a small amount of Y3 + doping can improve KCaPO4: Eu2 + phosphor luminescence intensity. Further study of the LiSrPO4: Eu2 +, Nd3 +, LiCaPO4: Eu2 +, Nd3 +, KCaPO4: Eu2 +, Nd3 +, NaCaPO4: Eu2 +, Nd3 + near-infrared light-emitting materials, influences of different Eu2 + emission wavelength of the Nd3 + near-infrared light-sensitized effect; systematic study the calcination temperature, calcination time, doping and other factors on the NaCaP04: Eu2 +, Nd3 + system, the impact of near-infrared light-emitting materials, analysis of the ABP04 system Eu2 +-Nd3 + energy transfer mechanism between. Degree Year: 2010

Tm ~ (3) / Yb ~ (3) co-doped calcium fluoride films and microspheres and optical properties of

Title: Tm ~ (3) / Yb ~ (3) co-doped calcium fluoride films and microspheres and optical properties of
Author: Jiang Tao
Degree-granting units: Jilin University
Key words: rare earth doped;; ultraviolet light;; conversion;; morphology
Summary:
In recent years, synthesis and structure to determine the shape of micro-nano size particles on the film or converted light-emitting materials has become a research hotspot. People can be infrared light into visible light, ultraviolet light and even convert inorganic materials on a lot of research work carried out, a variety of different synthetic and rare-earth-doped luminescent materials with specific morphology. As the fluoride material has a low phonon energy and a wide range of light wavelengths, making the non-radiative relaxation to reduce the likelihood of the process, upconversion efficiency is improved, therefore, become widely used fluoride conversion matrix one of the materials. At present, the preparation of efficient upconversion materials and upconversion mechanisms of its becoming a serious problem around this problem, this paper mainly carried out the following work:
(1) the use of sol-gel method with hydrothermal secondary growth under the conditions of preparation of the Yb ~ (3), Tm ~ (3) co-doped CaF2 film, get the surface of nano-size uniform thickness CaF_2: Yb ~ (3) / Tm ~ (3) film, its up-conversion emission spectra were measured, observed ultraviolet upconversion luminescence phenomenon.
(2) by hydrothermal method and were prepared by annealing a large number of nanoparticles composed of Tm ~ (3) / Yb ~ (3) co-doped CaF_2 micron particle conversion on the ball. Samples under 980 nm laser diode light glows bright blue and ultraviolet upconversion fluorescence. Experiment by changing the hydrothermal reaction conditions, adding a mineralizing agent and surface active agent prepared samples with different morphologies. We studied the formation mechanism of the product that the nucleation process of the sample in line with Oswald ripening process, while, on the observed UV up-conversion emission phenomena are discussed.
Degree Year: 2010

New rare earth terbium complex synthesis and application of fluorescent probes

Title: New rare earth terbium complex synthesis and application of fluorescent probes
Author: Chen Jin snow
Degree-granting unit: Dalian University of Technology
Key words: terbium complex;; fluorescent probe;; time-resolved fluorescence analysis;; biological imaging
Summary:
Long-life fluorescent probes based on rare-earth fluorescence properties of the developed high-sensitivity chemical and biological analysis of time-resolved fluorescence detection technology has been in clinical and biological technologies have been widely used. Magnetic lifter In this paper the study, design, synthesis and characterization of three respectively for the detection of Zn2, hydroxyl radical (-OH), H_2O_2 the terbium complex fluorescent probe; N, N, N1, N1-{2, 6-- bis (3'-aminopropyl-methyl-1 '- pyrazolate) -4 - [N, N-bis (2 - pyridylmethyl) aminomethyl pyridine]} tetra-acetic acid-Tb3 (BBATA-Tb3), N, N, N1, N1-[2,6 - bis (3'-aminopropyl-methyl-1 '- pyrazol-yl) -4 - (4'-aminophenoxy) methyl pyridine] tetra-acetic acid-Tb3 (BMPTA-Tb3) and N, N, N1, N1-[2,6 - bis (3'-aminopropyl-methyl-1 '- pyrazol-yl) -4 - (3', 4'-aminophenoxy ) methyl pyridine] tetra-acetic acid-Tb3 (BMTA-Tb3). Using NMR, elemental analysis and mass spectrometry by means of synthetic intermediates and final products were characterized by the establishment of terbium complexes based on the detection of Zn2, · OH, H202 of the time-resolved fluorescence measurement techniques and time-resolved fluorescence imaging technique.
Three kinds of fluorescent probe itself is very weak, when the target substance detecting fluorescence quantum yield of reaction was significantly enhanced, as strong fluorescent complexes in aqueous solution can be achieved Zn2, · OH, H202 high-sensitivity detection. Which, BMTA-Tb3 detection of H2O2 in the horseradish peroxidase (HRP)-catalyzed achieve. Probes with long fluorescence lifetime, good water solubility, good stability, high sensitivity, http://www.999magnet.com/products/131-magnetic-lifter suitable for use under physiological conditions. After the probe is esterified through thin 'membrane into the cell, combined with time-resolved fluorescence microscopy imaging techniques, can effectively eliminate the short-lived background fluorescence from the scattered light and interference to achieve a living HeLa cells Zn2, · OH, H202 determination. Established a target in living cells highly sensitive detection method.
Degree Year: 2010

nano-micron composite structure based on fluorescence properties of control and catalyst design

Title: nano-micron composite structure based on fluorescence properties of control and catalyst designAuthor: Huang HuiDegree-granting units: Northeast Normal UniversityKeywords: micro-composite structure is satisfied;; rare earth oxides;; spectral properties;; photocatalystSummary:

Functional nano-composite materials with special optical, electrical, acoustic, thermal, magnetic and other properties in the nano-composite materials occupy an important position. Composite materials in the nano-micron degradation of organic pollutants, cleaning up the environment, development of new energy has an important significance, preparation of new Strong magnets functional nano-composite photocatalytic materials is a theoretical value and broad application prospects of an important issue. Around the new functional nano-composite photocatalytic materials research, we mainly conducted the following research areas:

(1) using sol - gel prepared by different oxide core-shell structure nanocomposites. Fluorescence properties of rare earth metals in particular, better use of europium, manganese magnetic better, as the shell, polystyrene? Zinc oxide? Such as yttrium oxide core, its morphology were characterized by testing its fluorescence properties, and found that its structure changes on the fluorescent properties of very weak.

(2) using sol - gel prepared by different metal-doped silica microspheres, and their morphology were characterized by testing its fluorescence properties. The product was a near-infrared excitation occurs near-infrared emission of the phenomenon, but still maintain the main features of silica microspheres. And the volume fraction of different kinds of metal with the nature and intensity of the fluorescence does not change.

(3) using the typical method of preparation of yttrium oxide, characterized by their morphology, the changing nature of the fluorescence test and found a very good red and blue fluorescence, but the photocatalytic effect is not very good.

(4) design an efficient light metals and metal salts compound catalyst. At room temperature using a simple solid-phase synthesis of metallic silver and silver nano-particles with the formation of photocatalyst. Characterize their morphology, to test their http://www.chinamagnets.biz/ photocatalytic ability, and discuss the strength of the photocatalytic mechanism.

Scanning electron microscopy (SEM), fluorescence spectroscopy (PL), UV - visible spectroscopy (UV-VIS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy and other means of testing the product's shape, structure, range of fluorescent light , UV absorption properties of a series of characterization.Degree Year: 2010