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CrAPO_4-5的合成及对环己烷选择性氧化的研究 被引量:2
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作者 张毅 常有国 +2 位作者 王学丽 肖兵 连丕勇 《石油化工高等学校学报》 EI CAS 2005年第4期1-4,共4页
以三乙胺为模板剂,拟薄水铝石为铝源,磷酸为磷源,在55℃恒温水热合成过程中加入硝酸铬,制备出CrAPO4-5分子筛,通过粉末X射线衍射(XRD)、红外光谱(IR)、氨程序升温脱附(NH3-TPD)、魔角核磁共振(MAS NMR)等手段进行了表征,发现所合成的分... 以三乙胺为模板剂,拟薄水铝石为铝源,磷酸为磷源,在55℃恒温水热合成过程中加入硝酸铬,制备出CrAPO4-5分子筛,通过粉末X射线衍射(XRD)、红外光谱(IR)、氨程序升温脱附(NH3-TPD)、魔角核磁共振(MAS NMR)等手段进行了表征,发现所合成的分子筛具有良好的晶体结构,且证明了Cr原子进入分子筛骨架。以CrAPO4-5分子筛为催化剂,以空气为氧源,考察了反应温度、时间、引发剂等因素对环己烷选择性氧化的影响。结果表明,在环己酮为引发剂情况下,反应压力为1.6 MPa,温度为160℃,反应6 h后,环己烷转化率可达20.6%,醇酮总选择性为95.7%。说明CrAPO4-5分子筛具有良好选择性和活性,是一种温和的氧化催化剂。 展开更多
关键词 crapo4-5 分子筛 选择性氧化 环己烷
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Evaluation of Spirometry for Medical Clearance in Occupations Requiring Respirator Usage
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作者 Ushang Desai Giffe T. Johnson +1 位作者 James D. McCluskey Raymond D. Harbison 《Occupational Diseases and Environmental Medicine》 2017年第3期67-77,共11页
Medical certification of workers for respirator use is an important activity of occupational medicine health professionals. Spirometry is a diagnostic tool to evaluate respiratory distress/insufficiency that may affec... Medical certification of workers for respirator use is an important activity of occupational medicine health professionals. Spirometry is a diagnostic tool to evaluate respiratory distress/insufficiency that may affect respirator use. The pulmonary function data of 337 subjects from different occupations that required medical evaluation to wear a respirator were analyzed to determine the effect of using various spirometric equations on respirator fitness outcomes. Of 337 subjects who were cleared for respiratory use by medical questionnaires for respirator compliance, 14 (4.15%) failed to pass respirator compliance by NFPA criteria and 5 (1.48%) failed to pass respirator compliance measures by ATS criteria. We compared the use of different spirometric equations to evaluate these measures, and it was determined that the Crapo equation cleared more workers for respirator use as compared to the Knudson and NHANES III equations. As some workers were able to qualify for respirator use based on questionnaire alone but failed respirator clearance after pulmonary function testing, it is recommended that spirometry is used to evaluate clearance for all workers who will use a respirator in the workplace. As well, using different spirometric equations can affect the outcome on passing or failing clearance for respirator use, and this should be considered in a respiratory medical certification program. 展开更多
关键词 SPIROMETRY NHANES III crapo Knudson RESPIRATORY Protection PROGRAM
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