Orthogonal experiments for controlling the formation of DBPs during preozonation of bromide-containing raw water

Orthogonal method was adopted to optimize the preozonation process and to minimize the bromate formation. Factors such as contact time, pH and ammonia concentration were investigated by orthogonal experiments to understand the interaction of various operation conditions on the formation of bromate and other disinfection byproducts （DBPs）. Results showed that pH had the most significant influence on the minimization of bromate formation. The factors influencing the formation ofbromate were in order ofpH 〉 contact time 〉 ammonia concentration. For the formation of trihalomethanes （THMs） and haloacetic acids （HAAs）, however, contact time significantly influenced their formation potential. In the practical preozonation process of waterworks, it is appropriate to set preozonation contact time to be 20 min. In order to minimize the formation of bromate, pH value of the raw water should be adjusted to 6.0, and a certain concentration of ammonia could be added into the water to strengthen the minimization effect when the concentration of bromide in the raw water is higher than that in the experimental water.     

基于句法分析的实体关系抽取

针对领域本体构建中实体关系种类不明确,以及中文文本中多出现复杂句式,复杂句子中实体关系的获取比较难的问题,提出基于句子语法分析的实体关系获取方法,通过对句法结构的分析,加入句法特征。以旅游领域的实体关系获取为模型分别进行二组实验。实验表明,基于SVM关系抽取实验中,加入了句法特征的那组实验结果的F值提高了15个百分点,证明句法特征对基于SVM的实体关系获取的有效性。