Structural and opto-electrical properties of pyrolized ZnO-CdO crystalline thin films

A series of ZnO-CdO thin films of different molar ratios of Zn and Cd have been deposited on glass substrate at substrate temperature ~ 360 ℃ by the spray pyrolysis technique at an ambient atmosphere. X-ray diffraction (XRD) studies confirmed the polycrystalline nature of the film and modulated crystal structures of wurtzite (ZnO) and cubic (CdO) are formed. The evaluated lattice parameters, and crystallite size are consistent with literature. Dislocation density and strain increased in the film as the grain sizes of ZnO and CdO are decreased. The band gap energy varies from 3.20 to 2.21 eV depending on the Zn/Cd ratios in the film. An incident photon intensity dependent I-V study confirmed that the films are highly photosensitive. Current increased with the increase of the intensity of the light beam. The optical conductivity and the optical constants, such as extinction coefficient, refractive index and complex dielectric constants are evaluated from transmittance and reflectance spectra of the films and these parameters are found to be sensitive to photon energy and displayed intermediate optical properties between ZnO and CdO, making it preferable for applications as the buffer and window layers in solar cells.     

台达PLC在污泥干化控制系统中的应用

为提高污泥干化系统自动化控制能力,采用DVP-60ES系列PLc和德力西CDI9200系列变频器,工控机,组织了一个基于工控机(I Pc-610MB)、PLc、变频器、电动执行器的无害化污泥干化自动控制系统。该控制系统分为3个部分:电气控制部分、PLc程序的开发、人机界面的开发。分析了系统工作的基本原理和主要过程,介绍了系统的硬、软件构成及其特性。通过一年多生产表明,该系统设备运行效果良好。     

柳树河油页岩微波干燥孔隙及内部水分扩散特性*

以柳树河油页岩为原料在微波功率为300W、400W、550W 条件下进行干燥试验,结果表明:对干燥处理后样品进行脱附/ 吸附、孔径和比表面积及孔特性测定得出,微波干燥有利于中孔的形成;运用Fick 第二定律对水分有效扩散系数进行分析可知,由于较高微波功率会在原料中心和表面产生很大的蒸汽压差,导致水分的有效扩散速率在加速干燥段与微波功率成反比;降速干燥段与微波功率变化成正比,但总体上还是随着微波功率的增加而增加。     

沥青温拌定量喷洒装置的设计

介绍了沥青温拌定量喷洒装置的结构,采用PLC对沥青温拌定量喷洒装置的电气系统进行控制,同时依靠触摸屏完成系统状态监视和过程控制,通过PLC及组态软件MCGS实现温拌添加剂无人工操作、完全自动化的定量喷洒,具有控制精度高、自动,手动灵活切换的优点。     

NiZn铁氧体粉料生产中喷雾造粒用料浆的研究

通过控制料浆中粉料的粒度及料浆固含量,制成喷雾颗粒料。研究了在此条件下制成的喷雾颗粒料特性。结果表明:当粉料的粒度(D50,下同)控制在1.5μm时,颗粒料中聚乙烯醇的质量分数可从0.73%增加到1.33%,从而使喷雾颗粒料的粘结性得到加强;当料浆固含量(质量分数)由64.52%增加到68.97%时,喷雾颗粒料的表观密度由1.30g/cm3提高到1.40g/cm3以上。     

衬底温度对ZnO纳米结构的影响

利用超声喷雾热解(USP)技术,以普通玻璃为衬底,制备了不同衬底温度下的系列ZnO薄膜.用扫描电镜(SEM)和X射线衍射(XRD)研究了衬底温度对ZnO结构的影响.结果表明,薄膜的微观结构随衬底温度变化显著.在410℃获得了ZnO纳米棒,纳米棒直径在50 nm左右,沿c轴择优生长,结晶质量较好.     

小型直喷式柴油机喷雾特性的试验研究

为了掌握喷雾的结构物特性,利用高速摄像装置和高压容器拍摄了喷雾的逆光图像,并研究了喷雾周围介质压力对喷雾贯穿距离、喷雾锥角以及蒸发等喷雾特性的影响。在液滴数密度较大的条件下,燃料液滴的蒸发速率传热过程和雾化质量的影响;喷射妆期喷雾的贯穿距离和贯穿速度几乎不受介质物影响;喷雾的贯穿跨离受喷油压力的影响不大,但随着喷油压力的提高,喷雾锥角增大,喷雾质量得到改善。     

Determination of pistachio drying behaviour and conditions in a solar drying system

The main object of this study is to determine the drying behaviour and conditions of shelled and unshelled pistachio samples using both solar assisted and open sun drying. For each drying experiment, 100 g each of unshelled and shelled pistachio were used. The least‐squares method was applied to find the drying curve equation of pistachio. During the experiments, shelf temperatures, weight loss of pistachio, moisture content of air, and distribution of solar radiation were measured; and presented depending on the drying time. Also, the mass shrinkage ratios of shelled and unshelled pistachio samples were determined, and the experimental uncertainty ratio was calculated as 15–16.5 per cent based on the experimental results. It was deduced that the shelled and unshelled pistachio samples in the solar assisted forced convection dryer were perfectly dried at temperatures of 50±10°C in the time period of 6 h. Whereas, the samples in the open sun drying were not sufficiently dried at temperatures of 28±4°C in the same time period. Hence, it is suggested that the pistachio samples with approximately 29.0 per cent of moisture are dried in the solar assisted convection dryer at 50±10°C of temperature in the time period of approximately 6 h in order to protect from the negative climatic and environmental effects. However, it is not desirable to dry the pistachio samples in the open sun because of greater drying time, dirt, dust and harmful insects. Copyright © 2001 John Wiley & Sons, Ltd.     

喷射成形技术的应用及产业化发展趋势

对喷射成形技术的特点及发展趋势进行了综合评述,分析了如何选择合适的应用对象来确定具体的产品形式及合金体系,并探讨了将其产业化的典型对象.     

无源自动水喷淋系统

文章通过对民爆行业消防系统功能现状分析,指出了某些现实存在的问题,肯定了无源自动水喷淋系统是一种能自动监测温度异常或险情发生后立即自动采取灭火动作的本质安全消防技术。