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400型工业光度计使用中的几点经验
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作者 王辅国 《分析仪器》 CAS 1992年第2期73-74,65,共3页
目前我国硝酸生产对于硝酸浓度主要仍是人工测量,大多数化验室采用中和法和比重法.我们曾经用自制电导仪测量,效果也不令人满意. 为了实现自动分析,我们引进了美国杜邦公司生产的400型工业光度计,利用硝酸能够选择性吸收特定波长紫外线... 目前我国硝酸生产对于硝酸浓度主要仍是人工测量,大多数化验室采用中和法和比重法.我们曾经用自制电导仪测量,效果也不令人满意. 为了实现自动分析,我们引进了美国杜邦公司生产的400型工业光度计,利用硝酸能够选择性吸收特定波长紫外线的特点,自动连续检测流程中的硝酸浓度,监控产品质量. 但是在应用工业光度计的过程中也遇到许多问题,经过多次改进,才逐渐运转正常. 展开更多
关键词 工业光度计 使用 光度计
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Low Blood Lead Concentrations and Cognitive Development of Primary School Children from Three Areas in Malaysia
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作者 H. Zailina R. Junidah +2 位作者 M.E. Saliza B.S. Shamsul H.H. Jamal 《Journal of Environmental Science and Engineering》 2011年第4期493-499,共7页
A study on to identify the relationship between blood lead and cognitive development was conducted on primary school children in Malaysia. About 413 children aged 62^/1 - 82^/1 years from urban (236), rural (80) a... A study on to identify the relationship between blood lead and cognitive development was conducted on primary school children in Malaysia. About 413 children aged 62^/1 - 82^/1 years from urban (236), rural (80) and industrial areas (97) were studied. Blood lead was analyzed using the Atomic Absorption Spectrophotometer (GFAAS). Cognitive development was measured by the 'McCarthy Scales of Children's Abilities Test' (MSCA). Significant differences found in the mean cognitive scores between the urban (94.40), industrial (102.90) and suburban children (101.24) (p 〈 0.001), with the blood lead between the urban (3.66 p.g/dL), industrial (3.54 μg/dL) and suburban children (3.04μg/dL) (p = 0.022). Significant inverse correlations between blood lead and cognitive scores found for all groups (p 〈 0.001), urban (p 〈 0.001) and suburban children (p 〈 0.001). Low blood lead significantly influenced the cognitive development for all children after adjusting for confounders (p _〈 0.001). The urban children's cognitive scores were significantly influenced by blood lead levels and household income (p 〈 0.001). However, for the suburban children, the cognitive score were significantly influenced by the blood lead levels, the mothers' education, number of siblings, sequence in the family and the household income (p 〈 0.001 ). Blood lead below 10μg/dL influenced the cognitive development. Urban children had higher blood lead but suburban children with lower blood lead were also vulnerable to the effect of lead on their cognitive development. 展开更多
关键词 Low blood lead school children cognitive development.
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