超声波降解苯酚废水的研究

利用超声及超声组合技术降解含酚废水,实验中研究了苯酚初始浓度、声强及H2O2浓度等组合技术对超声降解苯酚反应的影响。结果表明在初始浓度为25 mg/L,H2O2的添加比例为1.0%、超声声强为4.97 W/cm2,催化剂添加量为1.0 g/L的条件下能有效降解苯酚,反应4 h后测得苯酚降解率为89.52%。     

对硝基氯苯生产中卧式和翅片式结晶器的应用比较

本文介绍了对硝基氯苯生产中常用卧式结晶器和翅片式结晶器的结构形式,并通过公司实际运行情况对两种结晶器的结晶周期、结晶效率、结晶电耗进行比较。运行表明,与卧式结晶器比较,采用翅片式结晶器结晶周期缩短27.8%,结晶器结晶效率提高,结晶电耗下降。     

油污染地下水回用处理工程实例

结合某油污染地下水回用处理工程实例,介绍了含油污水回用处理工艺流程和主要装置;分析了该工艺的水处理成本,指出了降低成本的主要途径;同时分析了装置的运行效果,由于进水水质高于设计值及工艺本身存在的问题,出水水质比控制指标稍差;最后结合装置的运行效果,探讨了工艺存在的问题及解决措施。     

Light assisted room-temperature NO2 sensors with enhanced performance based on black SnO1-α@ZnO1-β@SnO2-γ nanocomposite coatings deposited by solution precursor plasma spray

The development of room-temperature gas sensors with high performance for nitrogen dioxide gases is of great importance and appealing. Our previous works show that visible light illumination is an effective method to replace heating. In this paper, solution precursor plasma spray (SPPS) process is used to prepare black SnO_1-α@ZnO_1-β@SnO_2-γ sensitive coatings. Stoichiometric ZnO, SnO₂ and SnO are in white color. The introduced highly concentrated donor defects provided by SPPS process make them turn to black. The light absorption range of the black coatings was extended from ultraviolet area to yellow light region. Raman spectroscopy, photoluminescence spectroscopy and X-ray photoelectron spectroscopy were used to characterize the chemical compositions and oxidation states of SPPS coatings. Donor defects formed deep donor levels between the valence band and conduction band, which can be excited under visible light illumination. FE-SEM and HRTEM images exhibited a highly porous nanostructure, and n-n heterojunctions were formed between SnO_1-α, ZnO_1-β and SnO_2-γ. The SPPS coatings exhibited an obvious response towards 1.0 ppm NO₂ gas under visible light illumination at room temperature. The enhanced sensing performance was mainly attributed to the presence of donor defects and homogenous heterojunctions.     

一种低成本环保处理酸雾的方法

利用在酸洗池上方加装酸雾收集器,在酸雾收集器内形成一定的负压,配合缓蚀剂的抑雾作用,阻隔酸雾的扩散,回收的氯化氢水溶液用于新酸洗液的配制。本方案成本低,效果显著,可适用不同大小,形状的酸洗池。     

PTA生产现状及展望

介绍了PTA的生产工艺和仪征化纤精对苯二甲酸(PTA)的生产现状,并从PTA产业国家和行业导向、区域经济发展方向、加快原料PX建设和保障以及加大行业竞争力的建设等方面对发展前景进行了展望。     

Zinc ferrite based gas sensors: A review

Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe₂O₄) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in zinc ferrite based gas sensors. We first discuss the general gas sensing mechanism of ZnFe₂O₄ sensor. This is followed by a review of the recent progress about zinc ferrite based gas sensors from several aspects: different micro-morphology, element doping and heterostructure materials. In the end, we propose that combining ZnFe₂O₄ which provides unique microstructure (such as the multi-layer porous shells hollow structure), with the semiconductors such as graphene, which provide excellent physical properties. It is expected that the mentioned composites contribute to improving selectivity, long-term stability, and other sensing performance of sensors at room or low temperature.     

数控激光切割机传动系统的研究

目前国内绝大多数数控激光切割机的传动系统均采用齿轮齿条传动方式。文章对传动系统的惯量匹配、减速箱传动偏差、齿轮齿条运动副刚度以及横梁等环节进行了分析和研究,得到的方法和结论对数控激光切割机的设计和开发具有一定的理论参考价值。     

激光切割机升降工作台液压系统的设计

设计了一种用于激光切割机升降工作台的液压系统。该系统采用双联泵、串联液压缸、调速阀等实现了四个液压缸动作同步。     

压力机的密封

详细介绍了压力机密封的原理,密封的泄漏机理,密封的分类、应用、要求、选择以及安装,并结合压力机的特点叙述了各种密封件在压力机中的应用及其注意事项。