开设实验室废液处理综合设计实验

将实验室废液回收列为综合性设计性实验课题,通过学生综合设计实验对各类无机废液进行简单有效的处理和回收。总结了实验室废液处理综合设计实验教学的组织和运行模式及各类无机废液的回收处理方法,最大限度降低了实验室废液对环境的污染。     

用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜

Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and poly-vinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SA-PVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of differentsodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance wereinvestigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranesfor ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SAconcentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 C, SA-PVA/PSF hollow fibercomposite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2.h). Besides, SA-PVA/PSF hollow fibercomposite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solutionon pervaporation performance.     

用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜

Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and polyvinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SAPVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of different sodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance were investigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranes for ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SA concentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 ℃, SA-PVA/PSF hollow fiber composite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2·h). Besides, SA-PVA/PSF hollow fiber composite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solution on pervaporation performance.     

涉及家电耗能的几则试题

随着人们生活水平的不断提高,越来越多的家电产品进入寻常百姓家,家用电器工作时每时每刻都在消耗电能,虽然短时间内消耗电能较小,但从长时间内考虑,它们消耗电能的数量相当大,降低耗电能量就成了人们普遍关心的问题。这类题一般计算量并不很大,计算过程也不很复杂,重点考查学生灵活运用物理知识巧妙解决实际问题的能力,但得分率并不很高,以下是从今年全国各地中考物理试题中精选的几例典型试题,供同学们学习参考。     

如何用数学方法解决物理问题

问题1一只刻度均匀但标度不准的温度计,把它的玻璃泡浸没在纯净的冰水混合物中,温度计的示数为4℃,在把它放在一标准大气压下纯净的沸水中,他的示数是84℃.如果他在空气中的示数为24℃,则当时的实际气温是多少?若把它放在实际温度为-10℃的冰箱中,则温度计的示数为多少?     

“物态变化”复习指导

一、温度和温度计温度是表示物体冷热程度的物理量.摄氏温度是这样规定的:把冰水混合物的温度规定为0℃,把标准大气压下沸水的温度规定为100℃.液体温度计是根据液体热胀冷缩的性质制作的.使用温度计前一定要观察它的零刻线、量程、分度值,会用正确的方法测物体的温度.     

浅议现代教育技术的应用

1．感性呈现 小学生认识世界主要是通过感性方式实现,动画因其逼真性、情节的趣味性和色彩的生动性极易激发学生的兴趣,使学生疆直观地获得感性认识。比如学习小学兰年级上册《地球上的水》一课时,上课开始我就借助多媒体播放一幅优美的山水图,屏幕上美丽如丽的景色配上动听的诗歌朗诵：“因为有你,小草变得嫩绿;因为有你,鱼儿游得欢畅……因为有你,     

观察水的沸腾典型题析

"观察水的沸腾"是第一个观察一种现象的全过程的学生实验,需要将眼、耳、口、手、脑全面协调配合,是培养学生操作、观察、作图、分析、交流与评价能力的开始.例1 在"观察水的沸腾"实验中:     

以电池为载体的中考题

电池是日常生活中的常见物质,引起人们对它关注的原因是污染问题,有资料显示一节电池能污染一平方米的土壤,污染的水量更是达到了一个人一生所需的饮水量.所以我们应该从现在做起,从我做起,注意做好废旧电池的回收、利用工作,真正做到保护     

让学生自己选择乃睿智之举

接连几周,集中听了校内不少教师上的课。感到受益匪浅的同时,仔细回想一下,有一些疑问觉得有必要弄明白,可又不知道该怎么解决为好。如在课堂教学中,如何解决学生水平之间的层次性?