绿色阻垢剂聚天冬氨酸的制备与性能研究

采用马来酸酐与氨水进行溶液聚合的方法制备聚天冬氨酸,利用静态阻垢法评价了聚天冬氨酸的阻垢性能。结果表明:聚天冬氨酸对ρ(Ca2+)=300mg/L,ρ(HCO3-)=300mg/L的水样阻垢率可以达到90%以上;在ρ(HCO3-)低于400mg/L时,药剂的阻垢率可达到100%;当ρ(HCO3-)大于400mg/L后,药剂阻垢性能降低明显。聚天冬氨酸具有良好的生物降解性,生物降解率可以达到70%。     

利用缺氧反硝化处理难降解有机物的探讨

本文研究了厌氧、缺氧实验夺件下难降解苯、甲苯、乙苯、二甲苯的同分异构体（BTEX）的生物降解性能。得出了不同底物的厌氧降解变化情况和缺氧降解条件下不同底物适宜的C／N比。通过对实验结果的分析，初步确定了不同底物具有各不相同的C／N比的原因，同时得出了缺氧反硝化与厌氧生物降解过程有可能同时发生的结论。     

基于交通量的平面信号控制交叉口交通冲突模拟研究

针对我国交通冲突技术发展尚处于起步阶段 ,交通冲突数据统计尚不充分的现状 ,笔者研究了交通量和交通事故、交通冲突的密切关系 ,尝试建立以交通量为基础的交通冲突数学模型 ,力求更加准确地对平面交叉口进行安全评价 ,克服传统的基于事故统计的安全评价方法的不足。     

Asbestos exposure among Seoul metropolitan subway workers during renovation of subway air-conditioning systems

Air quality in underground spaces has seldom been evaluated in Korea. Accordingly, the current study recently evaluated asbestos exposure among Seoul metropolitan subway workers during the renovation of the subway's air-conditioning system. To identify possible routes of asbestos exposure, suspected sources, including gaskets, ceiling boards, ceiling materials, and dust settled inside ducts, were all sampled. Personal air samples were also taken to evaluate any asbestos exposure during the renovation. The asbestos fibers found in the samples were analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer (EDX). Twelve out of eighteen bulk samples contained asbestos, the majority of which was chrysotile fibers. Asbestos was detected in 9 out of 72 personal air samples and the level ranged from 0.003 to 0.02 fibers/cm(3). While asbestos levels were below Korean occupational limit of 2 fibers/cm(3), they were still detectable and therefore further monitoring would be appropriate.     

Potential source of asbestos in non-asbestos textile manufacturing company

Recently, a worker with lung carcinoma and a metastatic brain tumor was diagnosed as having a work-related disease. He had been employed in a non-asbestos textile company for 25 years. Consequently, to identify and explore possible causative agents for lung cancer in a non-asbestos textile manufacturing company and establish a causal relationship between exposure and lung cancer, an epidemiological investigative study was conducted and the work processes the worker was engaged in were examined. Air samples were taken from the workplace and during the drilling processes, and a suspected causative material was analyzed. The study revealed that the subject had been employed in the non-asbestos textile manufacturing company for 25 years from 1973 and his responsibilities included repairing spinning machines. In particular, the subject was involved in drilling B-bushings that were used to protect against gear abrasion in the spinning machines. An analysis of the B-bushings using a transmission electron microscope equipped with an energy dispersive X-ray analyzer indicated that they contained crocidolite asbestos fibers. Air samples obtained when drilling the B-bushings clearly indicated that the subject had most likely been exposed to crocidolite fibers when installing the B-bushings in the spinning machines. The frequency and duration of the work suggested that there would be a sufficient degree of exposure to crocidolite fibers to cause lung cancer. Except for smoking and asbestos exposure, no other chemical exposure was suspected for developing lung cancer in the workplace. Smoking appeared to be more of a potentiating risk factor in conjunction with the asbestos exposure. Accordingly, this case may provide significant evidence in identifying the cause of the mesothelioma or lung carcinoma found among workers in non-asbestos textile manufacturing companies elsewhere.     

Biologically induced Po emission from fresh water

Behavior of Po in fresh waters was examined in laboratory culture experiments using fresh water collected from a small pool, Xi river and Xiqing lake, showing formation of volatile Po compounds followed by emission to air. Addition of tryptone to the fresh water cultures increased the emission of Po considerably along with a growth of microorganisms, suggesting a connection of chemoheterotrophs to Po emission. Participation of photoautotrophs was also considered because Po emission was increased when NaHCO3 was added to the fresh water cultures. The emission behavior of Po and S in these experiments appeared in different ways. The quantity of Po emitted was comparable to the previous culture experiments (Momoshima, Song, Osaki & Maeda, Environ. Sci. Technol., 35, 2956-2960, 2001) in which artificial culture medium containing 3% NaCl was used and inoculated with sea sediment extract. The biological support for Po emission, thus, would be a general phenomenon in fresh water as well as a seawater environment and is possibly a source for atmospheric Po.     

区域可持续发展生态评估的能值分析研究进展与展望

可持续发展的生态评估是当前国际生态经济学与可持续发展研究的前沿问题之一，能值分析以能量为单位定量评估人类生态经济系统中各种生态流的可持续性，是一个重要的研究方向。尽管能值分析定量评价了自然环境资源对人类生态经济系统的贡献．克服了传统能量与经济分析方法的诸多缺憾，但在理论方法上仍存在不足之处。综合国内外区域能值分析的最新进展。能值转换率的确定、能值分析与空阃格局分析的整合、能值成本价值论与市场（使用）价值论的整合、可持续性阈值等问题将是下一步的研究重点。     

西湖底泥对水中苯胺、苯酚的吸附性能及机理

研究了杭州西湖５ 个不同采样点底泥对水中苯胺、苯酚的吸附性能及机理,初步探讨了ｐＨ和振荡时间对吸附的影响．结果表明,西湖底泥中有机碳含量较高（５．６６％ ～１１．９０％ ）,对水中苯胺的吸附作用及其去除率与底泥的有机碳含量成正相关（ｒ＝ ０．９９８）;对苯酚的吸附作用及其去除率与底泥的比表面积成正相关（ｒ＝ ０．９４２）．     

悲剧何时了?

爆竹声中悲剧频发 1999年6月30日,河北省黄骅市齐家务乡高庄子村宋殿俊雇人偷运烟花爆竹原料藏匿到一土坯房内,在搬运过程中发生爆炸,造成5名雇工死亡;8月12日广西百色广西建华厂烟花一分厂因工人违章操作引发爆炸事故,造成2人死亡,7人受伤;9月12日,内蒙古自治区赤峰市喀喇沁旗马蹄营子乡山嘴子村村民张柏军雇 佣村民在家中非法生产烟花爆竹时,违反操作规程引发爆炸,造成2人死亡,5人受伤;10月24日,河南省叶县仙台镇辛楼村村民辛国领非法开办的烟花爆竹作坊发生爆炸,造成8人死亡,7人受伤,8间房屋被炸毁,30余间房屋被损坏;10月24日,福建省仙游县象岭村村民傅细华在家中非法生产引火线,引发爆炸,傅等4人死亡。     

废高磁合金钢中钴、镍的分离和利用

用硫酸、盐酸和硝酸溶解废高磁合金钢、并将Fe^2 氧化为Fe^3 。先用黄铁矾法除去大部分铁,用尿素除去少量的铁及铝、钛、铜;最后在NH3－NH4Cl体系中分离钴、镍,并制成相应的盐。钴、镍的回收率分别国81．5％、89．7％。