鉴别红葡萄酒中添加人工色素或天然色素的简易方法

目的:鉴别红葡萄酒中是否添加合成人工色素以及天然色素(以葡萄皮红色素为例)。方法:对葡萄酒样品、人工色素模拟酒和天然色素模拟酒样品在碱性测试试纸上显示的颜色进行表征并对比。结果:当测试试纸显示的颜色为红色时,该红葡萄酒样品中含有人工色素;当测试试纸显示的颜色为蓝色,并在室温下暴露在空气中5min后不变色,则该红葡萄酒样品中添加天然色素,在5min内若由蓝色变为黄色,则说明该红葡萄酒样品中未添加天然色素,为全葡萄汁酿制而成。结论:该法简易快速,适合初步定性鉴别红葡萄酒中是否掺杂色素使用。     

工业粉尘云爆炸下限的实验研究

通过对主要工业粉尘爆炸压力测定，发现粉尘爆炸下限与测试用点火具压力和燃烧持续时间有关。对于不同的粉尘，通过燃烧时间来判断爆炸下限对于工业粉尘防爆设计具有实际意义。     

聚丙烯纤维接枝丙烯酸反应条件优化

The optimum conditions of grafting copolymerization reaction of acrylic acid (AA) onto polypropylene (PP) fiber was studied by using benzoyl peroxide (BPO) as initiator. The primary and secondary sequences of the grafting copolymerization reaction conditions was analysed. The results showed that grafting copolymerization reaction was greatly influenced by the temperature, reaction time, concentration of BPO and that of AA in the primary and secondary role as the above sequence. The optimum reaction conditions of gaining higher exchange capacity for the weak acidic cation-exchange fiber are as follows: the grafting temperature 80℃, the reaction time 7h, the concentration of BPO 2% and AA 80%.