裂解汽油在ZSM-5沸石上的芳构化

采用连续流动反应装置,考察了裂解汽油在HZSM-5与金属元素改性的HZSM-5上的芳构化反应,发现锌改性后提高了液体产物中芳烃的收率。为了克服裂解汽油中含硫含焦杂质的影响,提出了获取芳烃的有效工艺:蒸馏除焦-加氢预脱硫-氢气氛下芳构化反应-冷凝产物。用氨吸附的程序升温脱附法,将催化剂的酸性质与其催化芳构化作用进行关联,认为Zn改性后的HZSM-5催化剂具有较温和的酸中心,可能是其芳构化高活性与高选择性的原因。     

修订车间空气中溶剂汽油容许浓度的研究

通过对969例汽油作业工人的体格检查和对86个作业点760次车间内汽油浓度的测定结果表明,在达标的条件下,工人仍有神经衰弱,植物神经功能障碍的临床症状,说明现行车间的卫生标准应当进行修订。根据动物实验资料计算 MAC,180汽油为198.6mg/m~3,120汽油为225.0mg/m~3,二者相差不大,我们建议车间空气中溶剂汽油容许浓度可修订为200mg/m~3。     

甲基叔丁基醚无铅汽油肾脏毒性的实验研究

目的：了解甲基叔丁基醚（MTBE）无铅汽油对肾脏的毒性及毒作用机制。方法：昆明种小鼠经呼吸道静式染毒，MTBE无铅汽油22．9、11．4及2．3g/m^3每天一次，连续2h，共22d亚急性染毒。日立－7150型全自动生化仪检测血清中尿素氮（BUN）、肌酐（Cr）含量；肾组织均浆中丙二醛（MDA）和超氧化物歧化酶（SOD）含量分别用荧光法，邻苯三酚自氧化固定时间法测定；电镜观察肾皮质区超微结构的变化，结果：22.9g/m^3染毒组雌性小鼠血清中BUN含量与阴性对照组间比较差异有显著性（P＜0．05）；电镜观察到22.9g/m^3染色毒对照组雌雄性小鼠的肾小球基底膜，肾小管细胞线粒体及绒毛均未见显著异常改变。结论：MTBE无铅汽油对肾小球的滤过功能有一定的影响，雌性小鼠可能更为敏感。     

Recreational gasoline sniffing: acute gasoline intoxication and latent organolead poisoning. Case reports and literature review

Gasoline is a readily obtainable intoxicant that unfortunately lends itself to habitual abuse by sniffing, a practice found particularly among children and adolescents. The concerted effects of the multiple hydrocarbon and other constituents of gasoline result in a predictable acute toxic syndrome. Organoleads, primarily tetraethyl lead (TEL), cause a separate toxicologic symptom-sign complex that overlaps with the initial acute toxic syndrome. The different clinical symptomatology, effects on hemoglobin synthesis, and response to chelation therapy are all in keeping with the view that organolead poisoning is a separate and distinct toxicologic entity from that of classical elemental lead poisoning or "plumbism".     

汽油对作业工人神经行为的影响

目的　了解汽油对职业人群神经行为功能的影响。方法　应用ＷＨＯ 推荐的神经行为测试组合（ＮＣＴＢ） 对９２ 名汽油作业工人和８８ 名对照人员进行了神经行为功能测试,同时测定作业环境空气中汽油浓度。结果　接触组明显存在忧郁－ 沮丧的不良情绪状态,简单反应时慢于对照组,数字跨度、提转敏捷度、数字译码和目标追踪得分明显低于对照组,且行为功能得分随浓度的增高而降低。结论　提示长期接触汽油可影响工人神经行为功能。     

化工工艺设计过程中几种决策方法的应用

催化裂化汽油通过加氢处理可有效降低硫含量,是清洁汽油或清洁汽油调和油生产的重要过程。随着环保标准的日益严格,汽油加氢技术的研发和使用正日益受到重视,在技术开发、工艺设计、项目投资的过程中要面临诸多决策问题,从管理学角度对不同级别决策问题适用的决策方法和模型进行了介绍,并对定量决策方法、定性决策方法以及定量与定性相结合的决策方法使用场合提出了一些建议。     

钙改性NiO/ZnO-Al2O3-SiO2吸附剂反应吸附脱硫效果

通过浸渍沉淀法制备了钙改性NiO/ZnO-Al₂O₃-SiO₂汽油脱硫吸附剂,并与S-Zorb工业吸附剂进行比较。物理性质分析、X射线衍射和原位吡啶吸附红外光谱表征结果表明,钙改性NiO/ZnO-Al₂O₃-SiO₂吸附剂比表面积为137.7 m²/g,孔容为0.31 cm³/g,NiO及ZnO晶体分布均匀且L酸总量更多。在420℃、2.9 MPa、质量空速10.98 h^-1、氢油体积比48:1的条件下,催化裂化汽油中的硫含量从243.38 μg/g降至10 μg/g以下,汽油辛烷值仅降低0.3;新鲜和再生吸附剂穿透硫容分别可达57.12 mg/g及47.33 mg/g,经过长周期再生循环后脱硫性能保持优良。同时,物理性质分析、光电子能谱等表征结果表明失活吸附剂再生后效果明显改善,汽油中硫元素最终被ZnO吸附生成ZnS。     

由口腔手机消毒灭菌浅析维修人员的自我卫生防护

简述现今对口腔手机的消毒、灭菌的3种方式,并阐明其优缺点。以此为基点,来说明维修工程人员所面临的环境状况,讨论在实际工作中所应采取的措施。     

Methyl-tertiary-butyl-ether (MTBE) misclassified

Methyl-tertiary-butyl-ether (MTBE) was introduced into motor fuels in 1992 to reduce carbon monoxide automotive emissions in areas where the National Ambient Air Quality Standards for CO were exceeded. At a meeting of the National Toxicology Program's Board of Scientific Counselors (2-3 December 1998), data were presented showing that exposure to MTBE caused increased incidence of liver tumors, renal adenomas, carcinomas and interstitial cell adenomas of the testes in male, and lymphomas and leukemia in female CD1 mice [National Toxicology Program, 1998]. Despite this evidence, the NTP Board defeated a motion to list MTBE as "Reasonably anticipated to be a human carcinogen" by a vote of 6 to 5. This decision directly contravenes rules and procedures previously established by NTP for assessing carcinogenicity of chemical compounds. Good public health policy dictates that the NTP Board conduct another review of MTBE with proper consideration of the criteria that have been established for listing agents as carcinogens. Millions of Americans who are exposed daily to this chemical deserve an unbiased evaluation of carcinogenic agents being introduced into the environment.     

Epidemiology, toxicokinetics, and health effects of methyltert-butyl ether (MTBE)

This paper reviews the published information assessing the kinetics and potential for adverse health effects related to exposure to the fuel oxygenate, methyltert-butyl ether (MTBE). Data were obtained from previously published reports, using human data where possible. If human data were not available, animal studies were cited. The kinetic profile of MTBE in humans is similar for ingestion and inhalation. The concentrations of MTBE to which the general public is expected to be exposed are orders of magnitude below concentrations that have caused adverse health effects in animals. Controlled human studies have not replicated early epidemiology studies that suggested, but did not confirm, a possible association between MTBE exposure and nonspecific health complaints.