The Tb Doping Effect on the Room Temperature Magnetoresistance in(La_(1-x)Tb_x)_(0.67)Sr_(0.33)MnO_3(x≤0.4)

With substitution of La by Tb in (La_(1-x)Tb_x)_(0.67)Sr_(0.33)MnO_3, the room temperature magnetoresistance △R/R_0drops at first, then undergoes an increase near x≈0.1, and finally drops again. The value of room temperaturemagnetoresistance at a field H=12 kOe for (La_(0.9)Tb_(0.1))_(0.67)Sr_(0.33)MnO_3 is -3.56%. The enhancement of the roomtemperature magnetoresistance induced by an appropriate Tb substitution in (La_(1-x)Tb_x)_(0.67)Sr_(0.33)MnO_3 is correlatedwith the shifts of the Curie temperature and metal-insulator temperature to near room temperature. The drop ofthe room temperature magnetoresistance at large Tb doping-contents may be due to its lower T_C and T_(MI) far fromthe room temperature.     

燃油泵弹性薄元件断裂原因分析

从显微组织、断口形貌、原材料状态、加工工艺和装配等方面对燃油泵弹性薄元件在生产中常见的断裂原因进行了分析；并对其进行了工艺试验的对比分析。认为其失效模式主要与氢脆、回火脆及原材料组织状态有关。提出了预防措施。     

2,4,6-三氨基嘧啶在玻碳电极上的电化学行为

用线性扫描伏安法 (LSV)、循环伏安法 (CV)和微分脉冲伏安法 (DPV)等电化学手段研究了 2 ,4,6 三氨基嘧啶 (TAP)的电化学行为。结果表明 :该化合物在玻碳电极表面存在吸附特性 ,在 0 .1 0mol·L- 1 的 pH 5 .0Britton Robinson (B R)缓冲溶液中于1 .2 0V(vs.Ag/AgCl)处有一灵敏的氧化峰。在选定的最佳条件下 ,其浓度在 8.0× 1 0 - 6～ 3.2×1 0 - 4 mol·L- 1 范围内与氧化峰电流有良好的线性关系 ,检测限为 6.5× 1 0 - 6mol·L- 1 。     

分布式存储环境下的加性Schwarz方法

引言 区域分裂方法起源于古老的schwarz交替方法[l].八十年代末期,法国数学家P.L.LionS提出了schwarz交替方法的投影解释[2一4],使得人们对schwarz交替方法有了全新的认识,为其进一步发展奠定了理论基础.由于并行计算环境的逐渐成熟以及预处理技术的兴起和大规模科学计算的需要,由严格串行的scliwarz交替方法发展了多种可完全并行的     

Physical and Electrochemical Properties of Doped LiFePO4 as Cathode Material for Lithium-Ion Batteries

LiFePO4 cathode material was synthesized by a solid-state reaction using doping several elements (Nb5 ,Zr4 ). The starting materials were mixed with a high-efficient sander and treated thermally under flowing N2. The samples were characterized by X-ray diffraction (XRD), field-emission gun electron microscopy (FEG), and their electrochemical performance was investigated in the term of cycling behavior. Room temperature discharge capacity about 140.6 mA·h·g-1 was obtained at C/5 rate.     

Fabrication of NiO Buffer Layer for YBCO Coated Conductors by Combining Sputtering and SOE Method

In research of YBCO coated conductors, the development of a oxide template for epitaxial growth of YBCO is very important. Matsumoto et al have demonstrated the potential of the surface oxidation epitaxial (SOE) route for formation a cube textured NiO layer on nickel tapes. The epitaxial NiO functions as a buffer layer of chemical reaction between YBCO and nickel, and as a template for the epitaxial growth of YBCO. However, the surface quality of NiO is difficult to control and defects such as crack, spall and deep grooves exist in SOE NiO layer. A new approach combining sputtering and SOE method to obtain crack-free and cube textured NiO layer were reported. Ni tapes prepared by the combination of rolling and recrystallization were used for this work. A coating of Ni was first deposited on the tapes via magnetron sputtering. Then on the coating tapes, continuous and textured NiO layer were achieved by SOE technology.     

高速公路交通事件检测影响因素分析

高速公路交通事件的有效检测对保证交通安全、提高运输效率具有重大的经济效益和社会效益。文章首先对高速公路交通事件进行了种类划分,分别分析了常发性交通事件和偶发性交通事件对交通流的影响。采用交通仿真软件TSIS（traffic software integration systems）获取研究所需的数据,研究和分析如何进行交通事件检测算法的参数选择。通过对仿真数据的分析,发现以车辆占有率作为交通事件的检测参数更为合理。     

技术进步在经济增长中的定量描述

本文运用二元回归余值方程对GM厂在经济增长中的技术进步进行了估算和预测。     

提高学生制图能力灼见

本文对如何提高学生制图能力,适应工作需要,提出一些看法和做法。