Nanocrystallized tetragonal metastable ZrO2 thin films deposited by metal-organic chemical vapor deposition for 3D capacitors

ZrO₂ is a potential candidate for the realization of 3D capacitors on silicon for future Systems-on-Chip. This paper reports on the deposition of ZrO₂ thin films by metal-organic chemical vapor deposition on planar and 3D structures. Physico-chemical as well as electrical properties of the films are investigated. It is shown that the change of phase and microstructure of the film due to annealing at 900 °C under O₂ impacts directly on the electrical performance of the capacitors. Capacitance densities are 2 nF/mm² for planar capacitors and reach 8 nF/mm² for capacitors with pores etched in silicon with a 4:1 aspect ratio.     

单U和双U换热器地热井热响应测试与分析

对埋深分别为88 m和89 m的单U和双U型换热器地热井进行热响应测试,应用线源模型理论计算出两口测试井的土壤导热系数及钻孔热阻值,在保证测试仪向地热井输入恒定热流量的基础上,实测两地热井单位井深换热量分别为56 W/m和62 W/m,证明采用双U换热器的地热井传热特性要优于单U换热器地热井。     

室内恒温泳池综合节能方案研究

基于广州某会所室内恒温泳池的温湿度设计参数,计算了该泳池全年制冷、除湿、泳池加热和采暖负荷动态需求。通过分析动态冷热负荷曲线提出冷凝热回收应作为泳池综合节能方案的基本出发点,进一步比较了泳池专用热泵系统与全热回收风冷热泵系统两种方案的运行特点和全年能耗特性,并建议采用小型热回收型热泵系统与普通风冷热泵的组合方案。     

等加速等减速凸轮机构CAD/CAM的研究

基于CAXA制造工程师计算机软件平台,根据凸轮机构的工作原理,分析了凸轮机构从动件的等加速等减速运动规律,实现了凸轮轮廓线的设计,并通过计算机完成了凸轮的三维精确造型,该方法为凸轮设计、运动分析及加工制造提供了依据。     

An experimental study of relative humidity effect on VOCs’ effective diffusion coefficient and partition coefficient in a porous medium

Most building materials are porous media. As a critical environmental factor, the influence of relative humidity on VOCs diffusion is still not well understood. In this study, VOC transport and sorption in a porous medium in the building materials (calcium silicate) were measured under three levels of relative humidity (25%, 50% and 80%) by using a dynamic dual chamber method. Tests were conducted for water-soluble compound (formaldehyde) and non-soluble compound (toluene). In addition, the transport of acetaldehyde, hexanal, benzaldehyde, butanol and decane through the calcium silicate were also tested at 50%RH to study the relationship between the effective diffusion coefficient (D_e), partition coefficient (K_ma) and the VOCs’ physical properties (molecular weight, vapor pressure and Henry’s law constant). Experimental results showed that: relative humidity in the 80%RH led to a higher partition coefficient for formaldehyde compared to 50%RH. However, between 25% and 50%RH, there was no significant difference in partition coefficient. Partition coefficient of toluene decreased with the increase of humidity due to competition of water molecules for pore surface area and the non-solubility nature of toluene. Relative humidity had no significant influence on the effective diffusion coefficient on both formaldehyde and toluene for the range of moisture conditions tested. The solubility of VOCs was found to correlate with the partition coefficient of VOCs. The partition coefficient of VOCs was not simply inversely proportional to the vapor pressure of the compound, but also increased with the increase of Henry’s law constant.     

浅谈PLC控制的变频器恒压供水系统

阐述了采用变频器和PLC联合控制车间恒压供水系统,重点介绍了该系统的控制思路、系统硬件软件、恒压供水系统特点等内容。采用变频调速及PLC控制技术后,使系统具有节能、工作可靠、自动控制程度高等优点,大幅提高了供水的可靠性、稳定性等。     

浅谈无负压变频恒压供水

介绍了无负压变频恒压供水设备的结构组成及工作原理,通过将无负压变频恒压供水与传统二次加压供水设备进行比较,指出了无负压变频恒压供水设备的优点,并结合具体应用实例指出了该设备的缺陷和不足,以指导实践。     

变频调速系统在恒压供水中的应用

分别介绍了变频调速的节能原理和恒压供水内部PID调节原理,着重阐述了ATV61变频器的多种特殊功能,并结合实例介绍了变频调速系统在恒压供水中的具体应用,指出变频调速系统在多方面具有无可比拟的优势,并具有显著节能效果,值得推广。     

基于模糊控制理论的空压机组节能方法研究

空压机组节能恒压供气系统可简化为电机变频调速系统,变频系统通常具有非线性、上升时间长、滞后性大等特点,难以建立其具体数学模型。针对目前空压机组在节能效果上的不足之处,分析了变频调速实现节能恒压供气的优点及原理,采用PID模糊控制器对3个参数进行在线自整定,实现空压机数目及电机转速的自动调节,最终达到节约能耗的目的。对比仿真试验表明,系统的延迟时间短、超调量小,具有优良的调节性能。     

不同温度条件下煤对瓦斯的等温吸附实验研究

 为探索Langmuir方程吸附常数与温度之间的变化规律,利用HCA型高压容量法吸附装置,针对重庆能源投资集团松藻煤电公司8#煤层煤样,分别在温度为30℃、40℃、50℃、60℃、70℃条件下进行了煤对瓦斯的等温吸附实验。结果表明,当温度一定时,吸附量随瓦斯压力的升高逐渐增加并趋于一稳定值;压力一定时,随着温度的升高,煤的瓦斯吸附量呈下降趋势;而且,随着温度的升高,吸附常数a值有逐渐降低趋势,而b值明显呈线性关系显著下降;吸附常数a、b与温度T的分别符合二次函数和线性方程关系。