纳米稀土复合固体超强酸催化合成乙酸苄酯

采用共沉淀法制备了纳米稀土复合固体超强酸SO4^2-／ZrO2-2％Nd2O3催化剂，电镜分析表明，催化剂颗粒直径在25nm左右，比表面积测定：71．03m^2／g。酸强度-12．70〈Ho〈-11．99。并对合成乙酸苄酯的最佳反应条件进行了研究。研究表明：当苯甲醇与乙酸的物质的量比为1：2，反应时间为5h，反应温度为120℃，催化剂用量为6％苯甲醇的质量时，酯化率可达92．04％。研究发现，该催化剂可重复使用并可活化再生。     

Electrocatalytic activity of oxidation products of guanine and 5′-GMP towards the oxidation of NADH

We have studied the potential electrocatalytic activity towards the oxidation of NADH of several oxidation products of guanine and its derivative guanosine-5′-monophosphate (5′-GMP) on pyrolytic graphite electrodes (PGE). The distribution of products generated strongly depends on the experimental conditions. Our investigations focused on the oxidation products that are adsorbed on the electrode surface, are redox active and, exhibited electrocatalytic activity toward the oxidation of NADH. These compounds were electrochemically and kinetically characterized in terms of dependence of the formal potential on pH and electron transfer rate constant (k_s). The voltammetric and catalytic behavior of both guanine and 5′-GMP oxidation products was compared with that of other guanine derivatives we have previously studied. Some mechanistic aspects concerning the generation of the catalysts are also discussed.     

MC(Mid-Century)催化氧化过程的研究进展

介绍了MC催化氧化过程规律；从催化荆体系的改进、新型溶剂体系的开发、反应器构型和配套设施的改进、富氧氧化技术的开发等方面综述了近年来MC技术的发展；探讨了MC液相催化氧化技术应用范围的拓展以及MC液相催化氧化过程的发展方向。     

陶瓷原料中二氧化硅分析方法的对比与选择

本文综合各种文献 ,对陶瓷原料中SiO2 的各种分析方法的优缺点 ,使用条件 ,应用侧重点进行了比较与评述     

2-（4-氯苯氨基）甲基苯酚降解的动力学研究

采用高效液相色谱技术,开展了Fenton试剂对2-（4-氯苯氨基）甲基苯酚（CMP）的氧化降解动力学的研究。考察了初始双氧水摩尔浓度、亚铁离子摩尔浓度和温度等因素对CMP降解速率的影响,结果表明,当双氧水摩尔浓度、亚铁离子摩尔浓度增大和温度升高时,CMP的氧化速率明显加快。在30~45℃的温度范围内,其氧化降解符合假一级反应动力学模型,反应的表观活化能Ea为102.90kJ/mol。     

视觉检测系统中亮度不均匀背景的一种去除方法

刀具形状视觉检测系统中，照明不均匀对测量结果影响很大。针对这种情况，提出了基于二维二阶多项式拟合并去除不均匀背景的方法。遵循最小均方程差原理，给出了二维二阶拟合的矩阵表达式。在编制的程序中，拟合点以人机交互形式由鼠标点击选出，程序自动记录所选点的图象人材与亮度值信息，然后拟合出背景曲面，并以二值图象形式给出去除背景后的目标图象。对一幅光照模型未知的网络图象进行了背景去除，实验结果良好。     

非平稳时序循环平稳趋势提取与机械故障诊断

在简单介绍非平稳时序模型周期趋势项提取方法的基础上，提出了机械故障诊断和分析方法，该方法利用旋转机械出现故障以后所呈现的循环平稳特性，使用循环平稳分析方法剔除非平稳时间序列模型中的趋势项，然后建立平稳时序模型，用该模型进行机械故障诊断分析。并运用仿真和实例对方法的正确性进行了验证。     

Effects of coating thickness and residual stresses on the bond strength of ASTM C633-79 thermal spray coating test specimens

Wire-arc-sprayed nickel-aluminum is widely used in the aircraft industry for dimensional restoration of worn parts and as a bond coat for thermal barrier coatings and other top coats. Some repair applications require thick coatings, which often result in lower bond strength. A mechanism being investigated to ex-plain this decrease in bond strength is the free edge effect, which includes both coating residual stresses and coating thickness. The layer-removal method was used to determine experimentally the residual stresses in wire-arc-sprayed nickel-aluminum coatings of different thicknesses. Bond strength evalu-ations were performed using an improved ASTM C 633-79 test specimen. Finite-element analysis and fracture mechanics were used to investigate the effects of coating thickness and residual stress state on coating bond strength.     

数控机床的可靠性分析

从不同侧面分析了数控机床的可靠性,阐述了提高数控机床可靠性的方法。     

大型精密机械设备的验收与管理

对学院使用的大型精密机械设备——五轴加工中心和数控铣床等设备的安装条件、验收指标、技术管理和日常维护进行了阐述,确保设备到位后及时安装和有效使用。