工作场所空气中丙烯醛检测方法综述

丙烯醛属于高毒类化合物,严重危害人的身体健康。对目前测定工作场所中丙烯醛含量的一些主要的测定方法进行了综述,并对其优缺点进行了分析。     

Investigation on phosphorus halogen‐free flame‐retardancy systems in short glass fiber‐reinforced PC/ABS composites under rapid thermal cycle molding process condition

In this study, standard test specimens with flame‐retarded short glass fiber‐reinforced PC/ABS materials were fabricated under rapid thermal cycle injection molding condition by selecting a potassium perfluorobutane sulfonate flame retardant specially used for PC, FR2025, and two kinds of aryl phosphorus halogen‐free flame retardants, UN707 and PX‐220. The flame‐retardancy effect of the above different flame retardants on the studied systems was compared through combustion tests of the specimens. Meanwhile, the thermal and mechanical properties of flame‐retarded composites were studied by using the thermogravimetry analysis, dynamic mechanical thermal analysis (DMTA), and universal testing machine. The results show that the “candlewick effect” of fibers exacerbates the fire behavior of composites. With the increase of the aryl phosphorus halogen‐free flame retardants, the flame‐retardancy effect of composites is obviously improved, and the maximum thermal degradation rate of composites is significantly decreased. The UL94 combustion rating is improved, and the time of residual flame is substantially reduced with the increase of PC content under the same content of flame retardant. The DMTA results show that the flame retardants have a reinforcement action on PC/ABS matrix. However, the macroscopic mechanical properties are slightly decreased in the glass fiber‐reinforced composites because of the destructive effect of the flame retardants on the interface compatibility between matrix and fibers; the scanning electron microscopic micrographs of tensile fracture fully prove this action mechanism of flame retardants. In addition, the addition of toughener and antidripping additive significantly affects the flame retardancy and mechanical properties of composites. POLYM. COMPOS., 36:1653–1663, 2015. © 2014 Society of Plastics Engineers     

地方供电网可靠性评估

对鹤岗电网现存网络进行了可靠性分析,可靠性评估涉及到的节点有99个,线路60条,变压器32台。采用解析法进行可靠性分析,指出该地区供电容量分布不尽合理,应在适当位置增加变电所,通过计算看出该地区的电压水平普遍偏低,有必要实现无功就地补偿。     

纯碱包装除尘设计探讨

针对纯碱包装工序中布袋除尘器,存在的许多弊病,如:①清灰方式不当,产生粉尘的二次飞扬;②滤袋容易损坏,更换频繁;③碱尘易吸潮,容易在滤袋上结疤。为了解决这些弊病,笔者提出了解决办法。     

锂盐在铝电解中的作用

报道了锂盐在铝电解中的作用.阐述了其提高熔体的电导率,降低电解质的熔点,减少铝的溶解损失,减小极化电压,降低电解质的蒸气压及延长阴极寿命等优点.提出锂盐与其它添加剂的有机结合,可获得更大经济效益和社会效益的构想.     

稀土对Fe-17.5Mn合金阻尼性能的影响

利用倒扭摆仪对比研究了Fe-17.5Mn二元合金和Fe-17.5Mn-0.3Mm(富铈混合稀土)合金的阻尼性能,并借用Olympus显微镜观察分析了合金的微观组织.研究结果表明,在1000℃保温1h后水淬状态下,Fe-17.5Mn-0.3Mm合金的阻尼性能明显优于Fe-17.5Mn二元合金.在微量稀土元素的作用下,Fe-17.5Mn-0.3Mm合金中相对于Fe-17.5Mn二元合金其马氏体数量较多、板条较细薄,板条变薄且单位体积内界面面积增加,使振动的微观阻尼源增多,导致阻尼性能提高.     

氮化铝陶瓷浆料流变性能的研究

系统地研究了流延法制备氮化铝基片过程中影响流延浆料粘度的主要因素.分析了研磨时间、有机混合溶剂掺量、分散剂掺量及粘结剂、塑性剂对氮化铝浆料流变性能的影响,并对实验条件下测得的流变曲线采用Hershel Bulkley模型进行拟合,拟合出的Hershel Bulkley屈服应力τc较好地反映了浆料的稳定性,研究结果表明:分散剂掺量为2.5%(体积分数)时,浆料的τc较低;浆料的τc随固相体积分数的增加而增加;研磨时间为4h制备的浆料τc最低,流动性能最好;浆料的粘度随着塑性剂与粘结剂的比值R的增加而急剧减小,流变性能得到明显改善.     

TiO2电解制取Ti的热力学研究

钛作为一种重要的金属越来越为人们所重视,因此降低钛的生产成本势在必行.TiO2的直接电化学还原法是一种低能耗、无污染的绿色生产新工艺.目前国内外研究较多的制取钛的新工艺有:FFC剑桥法、EMR法和OS法等.通过TiO2电解实验得到了Ti,并进行了相关的热力学分析与计算,证明TiO2的还原是逐级进行的;同时分析了实验的主要影响因素及其控制方法,为进一步研究TiO2电解制取Ti的机理与工艺提供了一定的依据.     

Solidification Structure of Low Carbon Steel Strips with Different Phosphorus Contents Produced by Strip Casting

In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.     

表面包覆法制备高固相含量SiC悬浮液的研究

本工作试图通过有机包覆的方法改善SiC粉在水中的表面胶体特性,制备高固相体积分数的SiC粉体悬浮液。以制备的悬浮液的固相体积分数为衡量标准,分别确定了APS和PAAM包覆过程最佳条件．（1）APS包覆：时间为5h,温度90℃,APS的质量分数为5％,此条件下可以制得固相体积分数为45％的SiC悬浮液;（2）PAAM包覆：时间为5h,温度30℃,AAM的质量分数为2％,在此条件下可以制得固相体积分数为50％的SiC悬浮液．