吹扫捕集GC/MS测定水中VOCs的方法优化

针对传统吹扫捕集方法测定高沸点挥发性有机污染物回收率偏低问题,设计二次正交实验进行方法优化.结果表明,吹扫时间、吹扫速率及冷阱温度分别为19min、70ml/min和-130℃时高沸点化合物的平均回收率明显提高,检出限完全满足EPA方法要求.采用优化后的方法测定了官厅水库中VOCs的含量,VOCs的浓度范围为O.05～5.6ppb.     

用ICS-90型离子色谱仪测定水中钙离子的不确定度分析

对离子色谱法测定水中钙离子的不确定度进行评定,并分析了其影响因素主要有来自重复测量引入的A类不确定度和来自工作曲线的不确定度以及来自标准溶液的不确定度。     

舟山市海洋贝类生物体内的细菌学研究

对浙江省舟山市各区县海洋贝类体内细菌数量及优势细菌种类进行了初步研究。根据2004年8月的采样和实验室分析,结果表明,贝类生物体内的优势种为少动鞘氨醇单胞菌、温和气单胞菌、欧文氏菌属等,一些能够诱发疾病的如杀鲑气单胞菌、溶藻弧菌、腐败假单胞菌等的出现应当引起重视。对生物体内的细菌数量检测发现,弧菌和粪大肠菌群数量都比较高,弧菌的测值范围为50个/克~1.8×104个/克,几何平均为9.3×102个/克;粪大肠菌群的测值范围为2.0~23个/克,几何平均为12.0个/克,超国家海洋生物体内粪大肠菌群二类标准,超标率为91.7%。     

夏季上海城区大气中二氧化碳浓度特征及相关因素分析

利用连续自动监测仪器,获得CO2源区上海城区2010年夏季高时间分辨率的CO2连续监测数据.监测期间CO2平均浓度为414±16ppm,高于同期全球本底观测站约6%,与中国其他城市化地区的浓度水平基本相当或略低.CO2浓度日变化呈显著早晚双峰特征;周变化呈显著的波浪形,高值集中出现在工作日.除O3外,与其他污染物呈显著...     

Safety performance measurement in collectivized oil companies in China: Contribution of leading indicators to lagging indicators

With the collectivization of the Chinese oil industry, oil companies have been expanding in size. However, the intensified differences in the safety performance of subsidiaries have severely hindered the collaborative management of the headquarters. Understanding the safety status of each member is urgent for parent companies and their subsidiaries to identify gaps and make improvements. A unified set of safety performance indicators and a practical measurement tool are essential for the Chinese oil industry. Hence, this study identified a set of safety performance indicators encompassing both leading and lagging indicators using data envelopment analysis (DEA) and entropy weight method (EWM) to reveal the critical factors affecting the safety performance of the oil industry. A total of 300 front-line workers from eight subsidiaries of an oil company participated in the survey. The identified indicators were preliminarily weighted using EWM. Then, DEA was employed to measure the safety performance of the eight subsidiaries, demonstrating that management commitment was the most crucial factor in distinguishing safety performance; safety culture was more differentiated than risk management. Safety performance was not entirely positively correlated with safety investments, but the reasonable allocation of safety resources played a vital role. In addition, the weaknesses in each subsidiary's safety management were identified, and the quantitative effects of each leading indicator on safety performance were obtained.