低温色谱分离装置的升级与优化

在总结过去多年低温色谱发展的基础上,针对现有的分离装置提出了升级与优化的方案,包括控制系统的升级、低温流路的改造、低温尾气处理系统的研制和在线监测分析系统的优化.通过该方案的实施,将提高装置的自动化水平,实现装置的闭环运行和尾气中氢氦的有效分离,加快色谱柱之间的液氮转移,大幅度降低装置的运行成本.     

案例教学实例在化工原理教学中的应用

我们结合教学实践环节和教学体会,用工程实例探讨了案例教学在化工原理教学中的应用,将课堂的理论教学与工程实际问题有机结合,能够使学生更好地掌握化工单元操作的基本内容,学会如何将书本知识运用于工程实际问题,收到了很好的课堂教学效果。     

电容式触摸按键扫描灵敏度及防水性研究

作为新一代按键输入方式的触摸式按键已经在众多领域得到广泛应用,由于触摸输入方式采用非接触式的按键技术,因此其寿命远远超过机械按键,其可靠性也不会随着时间的延长而降低.但目前使用最普遍的电容式触摸按键也正处于发展和完善阶段,而电容式触摸按键扫描的灵敏性及防水性能一直是该技术所面临的最大难题.本文通过分析与按键扫描灵敏度相关的硬件参数,同时运用所设计的算法来区分和调控按键在无水及带水操作下的扫描处理方式,以实现电容式触摸按键扫描的灵敏性及防水功能.研究结果表明,所设计的电容式触摸按键反应灵敏、检测精准、具有一定的防水效果,较好地解决了该技术所面临的难题,并具有良好的市场前景.     

市政工程项目管理要点分析

从目前市政工程的开展来看,项目管理已经成为了保障工程建设有效开展的重要手段。所以,我们要对市政工程项目管理有足够的认识,并对市政工程项目管理要点进行认真分析,解决市政工程项目管理存在的问题,提高项目管理的实际效果。     

宽带无线IP实验系统

给出了一个宽带无线IP实验系统。该系统由4－6个移动终端、2个无线接入点和2个无线接入服务器组成，可提供2－11Mbps的高速无线传输，支持IEEE802．11b协议和移动IP协议，具有可靠的信息安全机制，可支持在移动环境下的WWW浏览、FTP、VOD等业务。提出了高效的UMPA的多址协议，该协议利用自组织算法来确定网络中的用户数，从而可以无冲突地安排各节点的传输。     

NUMERICAL STUDY OF RADIATIVE TRANSPORT HYDRODYNAMICS,AND CHEMICAL KINETICS IN A PHOTODISSOCIATION ATOMIC IODINE AMPLIFIER

Index-of-refraction changes induced by hydrodynamic activity have been blamed for poor beam quality in photodissociation lasers. Until recently, the pump field, hydrodynamics, chemical kinetics, and the losing field have been decoupled in theoretical models because of the wide range of time scales on which they act. Although these mechanisms occur at varying time scales ranging over seven orders of magnitude (subnanosecond to milliseconds), each mechanism strongly affects the others. In this paper we present a model that first couples the pump field, chemical kinetics, and hydrodynamics in the form of implicit and explicit finite-difference equations. We then couple in the laser field to show that index-of-refraction changes induced by radiative transfer degrade peak beam intensity     

Thermal performance of caprylic acid/1-dodecanol eutectic mixture as phase change material (PCM)

Differential scanning calorimetry (DSC) is used to investigate the thermal properties of caprylic acid, 1-dodecanol and their binary system. The experimental results show that the caprylic acid/1-dodecanol binary system presents eutectic point. The eutectic melting temperature (T_em) is 6.52 °C, and the latent heat of melting of eutectic mixture (ΔH_em) is 171.06 J g⁻¹. The corresponding mass fraction of 1-dodecanol in eutectic mixture is 30%. The eutectic melting temperature and the latent heat of phase change of eutectic mixture have not obvious variations after 60 and 120 thermal cycles, which proves that the eutectic mixture has good thermal stability.     

On Effective Design and Operating Conditions of Desiccant Dehumidification System

The present study investigates the effect of air flowrate on the adsorption systems both numerically and experimentally. Tests are performed with Zeolite 4A adsorbent. The size of test desiccant channel section is 10 cm × 10 cm × 10 cm, and three test sections in series connections are used as the test section during adsorption and desorption. During adsorption, the inlet pressure is kept at 9 bar while it is reduced to 1.16 bar during desorption. The simulation is first validated with the experimental data. The simulation indicates though a higher airflow during adsorption can produce dry air quickly but may not be able to attain a prescribed very low dew point temperature. Yet lower airflow can dehumidify more moisture and attain much lower dew point but requires substantial time. For the required energy to generate the same dry air flow volume in cyclic operation, it was obvious that a lower flowrate like 150 standard liter per minutes (SLPM) is about 4% lower than that of a higher flowrate of 400 SLPM. For effective regeneration during desorption, a non-uniform heating provided at the first section is proved to be much effective than the uniform heating. It is found that the desiccant loading for only heating at the first section outperforms other arrangements, giving 10% lower desiccant loading than the uniform heating.