金属有机物分解法制备钛酸铅薄膜

用金属有机物分解法制备了钛酸铅薄膜。研究了成膜的技术条件。一次甩胶可以获得厚约0.1μm均匀、无开裂、无针孔的薄膜,较厚的膜可通过多次甩胶得到。X射线衍射证实,经700℃热处理后,膜呈现四方钙钛矿的单相结构。Rutherford背散射表明,即使在多次甩胶制得的膜中,组份的厚度分布也是均匀的。     

膨润土负载纳米零价铁去除水中铅的研究

将纳米零价铁通过液态还原法负载于膨润土上,目的是为了比较负载对提高纳米零价铁去除重金属铅的能力的影响。从负载后扫描电镜图像中可以看出,负载后的纳米零价铁分散度更好。在相同投加量下,负载了纳米零价铁的膨润土对重金属铅的去除能力要远高于膨润土和纳米零价铁。铅的起始浓度为200mg／L,膨润土＋纳米零价铁的复合材料在0．4g／L的投加量下,去除率就达到90％以上。对材料的动力学研究结果则表明：纳米零价铁的反应速度较快,大部分的铅的去除都在1h以内完成。将吸附动力学实验结果进行一级和二级动力学反应拟合。二级拟和的线性相关系数明显高于一级。说明纳米零价铁和膨润土＋纳米零价铁复合材料与铅的反应更符合二级动力学反应假设。另外,纳米零价铁对铅的去除受到起始浓度的影响较大,而膨润土＋纳米零价铁则基本不受起始浓度的影响。     

我国居民膳食中铅摄入量调查与分析

采用统计学原理,对2005～2007年全国31个省市26大类食品中铅含量的抽样检测数据,进行了分析与评估.通过对数据的纵向和横向比较,得出：我国居民的铅摄入状况不容乐观,特定人群存在较大风险,我国城市居民的铅摄入风险要远高于农村居民.膳食中含铅量较高的是主食.     

Generation of sodium hypochlorite (NaOCl) from sodium chloride solution using C/PbO_2 and Pb/PbO_2 electrodes

Two modified electrodes (Pb/PbO2 and C/PbO2) were prepared by electrodepositing a lead oxide layer on lead and carbon sub-strates. These modified electrodes were used as anodes for the generation of sodium hypochlorite (NaOCl) from sodium chloride solution. Different operating conditions and factors affecting the treatment process of NaOCl generation, including current density, pH values, con-ductive electrolytes, and electrolysis time, were studied and optimized. By comparison the C/PbO2 electrode shows a higher efficiency than the Pb/PbO2 electrode for the generation of NaOCl.     

Two-echelon inventory model with service level constraint and controllable lead time sensitive to order quantity

The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity. First, the basic model of this problem was established and based on relevant analysis, the original model could be transformed by minimax method. Then, the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given. According to this boundary, the effective method and tactics were put forward to solve the transformed model. In case analysis, the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory. The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.     

基于MRD与LRB混合控制的隔震连续梁桥地震响应

为了研究磁流变阻尼器(MRD)与铅芯橡胶支座(LRB)混合控制对桥梁结构地震响应及隔震效果的影响,以典型三跨连续梁桥为背景,采用平行板模型模拟MRD的本构关系,采用Bouc-Wen模型模拟LRB的力-位移非线性行为,通过对结构的离散建立无控制、LRB单独控制、MRD与LRB混合控制的多种控制工况有限元计算模型,运用有限单元方法建立系统的动力特性矩阵,并采用瞬时最优控制算法对其进行了非线性时程对比分析.分析结果表明:采用MRD与LRB混合控制工况与LRB单独控制工况相比,前者的结构地震响应明显降低,隔震效果得到明显提高;在桥墩、桥台处均安装MRD与仅在桥墩或桥台处安装MRD的LRB隔震桥梁相比,前者对结构地震响应的控制效果更好.     

铌铁酸铅PFN的结构无序及介电相变特性

运用高分辨透射电镜显微技术观察到ＰＦＮ中Ｂ位离子呈无序排列，不易形成有序结构，在性能上，ＰＦＮ的介电常数ε和介电损耗ｔｇδ均很大，相变扩散度小；相应时的介电行为，热容和热膨胀的变化比较特殊。     

PbTiO3超微粉的介电性质

对于平均粒径２０～２００ｎｍ的ＰｂＴｉＯ３超微粉，首次通过它们的压块研究了介电性质。在粒径为３５ｎｍ左右时介电常数旦现峰值。     

红辉沸石对重金属铅离子的吸附性能

研究了红辉沸石对重金属铅离子的吸附性能:当pH值在4~5时,红辉沸石具有较好的吸附能力,其对铅的饱和吸附容量达0.831 mg/g.同时使用氯化钠和氯化铵对沸石进行改性,并用红外光谱法进行表征,证明处理后的红辉沸石结构上产生了明显的变化,有利于提高其吸附性能,其对铅的饱和吸附容量可达1.091 mg/g.