邻二甲苯泵用机械密封的失效分析

针对国产化过程中，邻二甲苯泵用机械密封工作时产生的故障，进行了失效分析。为邻二甲苯泵用机械密封的改造提供了依据。     

Solid circulation characteristics in an internally circulating fluidized bed with orifice-type draft tube

Effects of superficial gas velocities to a draft tube, to an annulus section and particle size on the solid circulation rate (G,) have been determined in an internally circulating fluidized bed (0.28 m I.D. × 2m high) with an orifice type draft tube. The solid circulation rate from the draft tube to an annulus section increases with increasing gas velocities to the draft tube(U _d ) and annulus section (U_a) and consequent increase in pressure drop across the orifice (ΔP_or). However, the values ofG _s decrease by 7–21% with increasing particle size from 86 to 288 μm. The pressure drop across the orifice increases with increasingU _d andU _a . However, ΔP_or decreases by 5–23% with increasing particle size. To predictG _s in an internally circulating fluidized bed, a correlation is proposed as a function of ΔP_or This paper is dedicated to Professor Dong Sup Doh on the occasion of his retirement Korea University.     

Characterization of pressure signals in a bubble column by wavelet packet transform

All experiments of pressure fluctuations were carried out in a bubble column with a moderately large column of 0.376 m ID. The recently developed technique of wavelet packet transform based on localized wavelet functions is applicable to analysis of the fluctuating signals. The time series of pressure fluctuation signals have been analyzed by means of wavelet packet transform components, decomposition through best basis algorithm and timefrequency representation. By resorting to this technique, the objects in bubbly flow regime have fine scales and frequencies than ones in churn-turbulent flow regime. Thus, this wavelet packet transform method enables us to obtain the frequency content of local complex flow behaviors in a bubble column.     

炭分子筛概述

阐述了炭分子筛分离的原理，并分别从其制备原料、制备方法、产品用途等方面综述了近年来炭分子筛的新进展。     

压力容器制造中材料代用的常见问题分析

就压力容器制造过程中常常遇到的材料代用问题进行综合分析,并阐述了相应观点。     

低压片状模塑料增稠工艺研究

采用氧化镁为增稠剂、结晶树脂以粉料形式加入而降低片材热模内粘度的工艺，改进了对低压片状模塑料的增稠方法。结果表明：采用此工艺，设备不需要加热，增稠符合传统SMC增稠曲线；片材在模腔内有较低的粘度，适宜于低压成型。     

化工容器设计规范述评

分析了压力容器设计标准ＧＢ１５０－８９［１］和ＪＢ４７３２－９５［２］在设计思想和设计方法上的主要区别及按两种标准制造的容器的经济性，提出了选取ＪＢ４７３２－９５作为所遵循的设计规范的一些参考性意见。     

以实例为切入点的高职物联网应用技术专业教育第一课

物联网技术发展迅速,但高职物联网应用技术专业教育尚处于初期,因而科学、直观、紧扣实际、有效激发学生专业学习的第一课尤为重要。以物联网应用技术实例为专业教育切入点,采用阶梯式递进的方法带领学生走进物联网,感知物联网,从而充分调动学生专业学习积极性,更好地让学生了解专业人才定位,明确学习目标和就业方向,为整个物联网应用技术专业教育打下坚实基础。     

高校公共基础课程教学改革与实践

就目前高等学校公共基础课程教育的现状,以计算机基础课程为例,探讨如何调整课程内容、尝试新型教学方式,论述如何开展公共基础课程教学方法与手段改革,通过课前、课堂和课后实施教学艺术,加强、充实实训内容,增进网络资源共享课程建设,促进教学质量提高。     

自控系统在加氢反应工艺中的应用

通过对化工生产中加氢反应的危险性简要介绍,并以某药厂对加氢反应工艺自控系统改造时从自控方案选择到自控参量、主要自控设施确定及安装、校验和系统调试等主要过程实施为例,说明此种危险可行性,为药厂类加氢工艺自控系统的技术改造提供相应的参考。