A fragment constant QSAR model for evaluating the EC50 values of organic chemicals to Daphnia magna.

The quantitative relationship between the median effective concentration (EC50) of organic chemicals to Daphnia magna and the number of molecular fragments was investigated based on experimental EC50 values for 217 chemicals derived from the literature. A fragment constant model was developed based on a multivariate linear regression between the number of fragments and the logarithmically transformed reciprocal values of EC50. Functional correction factors were introduced into the model. The model was verified using an independent set of randomly selected data. The mean residual of the final model was 0.4 log-units. The robustness of the model was discussed based on the results of three jackknife tests.     

某铀矿工人头发中总α,总β,铀,钍放射性水平的调查

本文对某铀矿职业工人和非职业工人头发中的总β、总α放射性水平和铀、钍含量进行了分析测定.结果表明,该矿工人体内铀和钍的蓄积量均在正常放射性本底水平范围内,从头发中检验未观察到工人体内铀、钍放射性水平有明显的升高.     

“华夏古陆”考异

自葛利普创名“华夏古陆”以来,经过半个多世纪的论辩与考订,对其地质构造属性,至今仍然否定与肯定交迭起伏,莫衷一是,本文从推覆构造,陆地漂移等实际资料着手,加以论证,认为它是经历深刻改造和发生巨大位移的变质岩断片体,地质构造属性已非“华夏古陆”原义。     

Concurrency: a system design approach to environmental management and sustainability

The lessons of history indicate that mismanagement of natural resources and the environment often leads to potentially adverse consequences.The increasing interest in economic development,particularly in the developing countries of the world coupled with increasing population pressures and the globalization of economic activity is placing noticeable stresses on the ultimate sustainability of both human and environmental systems.Sustainable development is not a new concept.It has been an area of concern for different elements of society for some time.Yet efforts to understand the implications of sustainable development have not,until recently,been formalized.We have focused singularly on economic development and environmental quality as if they were mutually exclusive.This paper focuses on the concept of concurrency as both a conceptual framework and practicable method of understanding and implementing the ecology and economy of sustainability.     

Microwave digestion method in environmental analysis

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效益型资源化啤酒废水处理技术应用及效果

本项处理技术屏弃了以往环境处理技术沿用的生产末端处理路线.根据啤酒生产工艺特点,在全面分析,平衡工艺废水的特性,数量及排放规律的基础上提出综合治理方案,着重于从废水中提取有用物质和能源,治理过程中把废水当做资源加以利用,而且具有明显低投入高增益的经济效益.装置2年来运行结果证明:核心技术——UASB 高效,实用,易操作,运行稳定居国内领先水平,其主要技术指标达到国内外同类研究的先进水平.该项技术可在啤酒行业及以粮食为原料的其它酿造行业和食品加工业中推广应用,并已被国家科委列为《国家级科技成果重点推广计划》及国家环保局最佳实用技术.     

电子设计竞赛与大学生创新能力培养

本文探讨了大学生电子设计竞赛对促进实践教学的重要作用，电子设计竞赛对大学生创新能力培养的作用，论述了高校深化实践教学改革与培养学生创新精神、创新能力的必要性。     

张恒东

原油管道储运行业地域辽阔、点多线长、易燃易爆，职业危害因素种类繁多，人员接触广泛，职业卫生 工作难度较大。笔者结合工作实际，就原油管道储运企业职业健康监护谈谈工作体会，     

Evaluation of inorganic pyrophosphate in amniotic fluid as a mode of prenatal diagnosis of osteogenesis imperfecta

Using a modified procedure by Solomons and Styner (1969), an evaluation of inorganic pyrophosphate (PPi) was performed on the amniotic fluid of two fetuses at risk for osteogenesis imperfecta (OI) at 14½ weeks gestation. The parents of both cases had a previous child with OI, Type II. The normal control group at 14–16 weeks gestation had PPi values ranging from 22.0–59.2 ug/100 ml, with a mean of 38.6±9.51 ug/100 ml. In each at-risk fetus, the amniotic fluid PPi value was within normal range. The first baby was born phenotypically normal at term. Intrauterine radiographic and fetal sonograms were done on the second fetus at approximately 19 weeks gestation. Both showed evidence of OI, Type II. The pregnancy was terminated at 21 weeks. Radiologic studies of the aborted fetus were consistent with OI, Type II. Our results indicate that the evaluation of PPi levels in amniotic fluid is not the method of choice for prenatal diagnosis of IO.