中文摘要：

氯乙烯是易燃易爆物质，一旦发生泄漏，就容易发生火灾、爆炸和中毒事故，从而造成财产损失和人员伤亡。本文采用单元危险性快速排序法对氯乙烯球罐进行了安全评价，确定了相应的危险等级，为企业的事故预防和风险管理提供了科学依据，最后提出了几点措施和建议。

英文摘要：

In this paper,by analyzing the curve characteristics of the electromagnet,a digital control constant current source design scheme which aim to make a novel magneto-optical modulator,was proposed.It works at a special zone,so that it avoids the magnetic stranded and saturation effects,and improves the speed to modulate the Stokes parametes.In the optimum range of drive current,it can ensure a linear relationship between the modulation current and the magnetic induction intensity.Compared with the traditional driver circuits,constant current source driver circuit’s modulation speed can be increased by more than 3 times,the system can be applied to a continuous variable coherent optical communication.