地下工程氡浓度监测与剂量评价

为了解某地下工程氡浓度水平,评估不同人群吸入氡及其子体所致年有效剂量,使用测氡仪对三个区域氡浓度进行了定期监测和连续监测。结果表明:地下工程氡浓度区域分布不均衡,高氡区浓度值约为低氡区的2倍,通风1~2 h后,高氡区氡浓度值下降约三分之一;区域氡浓度呈逐年下降趋势,连续三年剂量评估最大值分别为5.71 mSv、2.72 mSv、2.65 mSv,第一年的剂量评估最大值高于目标剂量限值3 mSv。测量结果可为环境条件改善、人员工作时间优化提供参考。

Purification of Two Antimicrobial Substances Produced by Bacillus subtilis Strain B11 and Their Properties

Two antimicrobial substances produced by Bacillus subtilis strain B 11 were purified by boiling, DEAE 52 anion exchange chromatography and aluminum oxide adsorption chromatography, These purified substances showed only one spot on silica gel thin layer chromatography （TLC）. Antimicrobial assays showed that antimicrobial substances A and B inhibited the growth of plant pathogens such as Fusarium oxysporum Schl f.sp. niveum, Rhizoctonia solani, Ralstonia solanacearum and Xanthomonas oryzae pv. oryzae. In addition, antimicrobial substance B could also inhibit the growth of Magnaporthe grisea. These two antimicrobial substances were resistant to proteolytic enzymes and temperature as high as 121℃.

基于综合判别方法的单相接地/PT断线故障自动判别及报警装置研发

在大型厂矿自备电厂的中性点不接地电力系统中,单相接地和PT断线故障时有发生,现有装置的判据较单一,经常出现判断不及时、误判或漏判。为解决上述问题,本文介绍了一种采用三相相电压幅值、差值、零序电压等信息综合判别单相接地/PT断线故障的类型、相别、故障发生具体位置的自动判别及报警装置的研发方法。

玛依河二级电站1、2号水轮机进水球阀密封油路进水问题分析

对玛依河二级水电站的1#,2#两台水轮机进水口球阀多年来一直存在球阀密封操作油路进水问题进行分析,找出其密封油路进水的原因、危害,提出了相应的处理措施及建议。