21世纪中国城市环境地质问题

从全球环境的角度对中国城市的环境地质问题进行了研究.文中分析了当今全球主要环境问题,探讨了全球环境变异对中国城市地质环境的影响,详细研究了现代城市工程经济建设中引起的环境工程地质问题.     

Evaluation of Caging Designs and a Fingernail Clam for Use in an In Situ Bioassay

Two cage designs and fingernail clams(Sphaerium fabale) were evaluated for theirsuitability for use in in situ bioassays toassess the ecological condition of a stream andpredict ecological recovery potential. One design(referred to as tray design) was a modified plastictray about one-fourth full of small gravels andcovered with 1 mm fiberglass mesh. The second design(referred to as tube-plates) consisted of shortplexiglass tubes about one-third full of small gravelsand attached horizontally to a plexiglass plate. Oneend of each tube faced into the current; both endswere covered with mesh. Cages containing clams weredeployed at reference and impacted (test) sites forperiods of 70 to 135 d. Growth and survival were theprimary endpoints evaluated, but the tube-platesallowed isolation of individual clams so that natalityalso could be evaluated as an endpoint. Results ofbenthic macroinvertebrate surveys, performed foranother study, were included to help validate bioassayresults. Both cage designs yielded good quantitative,site-specific results for clam survival and growth;results for natality, though, were less conclusive. Clam survival and growth results were in good generalagreement with the results for the benthicmacroinvertebrate community surveys. At a site wherethe macroinvertebrate community was the mostdepauperate, clam mortality was always rapid. At asite where the condition of the macroinvertebratecommunity was only slightly less impacted than themost impacted site, clam growth was almost alwayssignificantly lower than at reference sites. Survivalof clams was significantly reduced in <25 d at thissite in some trials, but in other trials there waslittle mortality. At a minimally impacted site, clamsurvival was similar to that found at reference sites,and differences in clam growth were not detectableuntil after 40 to 50 d of exposure. The tube-platedesign was easier to use, allowed more flexibility inselection of response parameters, and required lesshandling time of test animals, thus, this was thepreferred design. Our results demonstrated thateither in situ bioassay design can be used toaugment monitoring and assessment programs. Their useas a predictor of ecological recovery, however,requires further evaluation.     

空气中总悬浮颗粒物的X射线衍射定性分析研究

以天津市环境监测中心采集的空气中总悬浮颗粒物（ＴＳＰ）膜（９７１０１２号）为样品,使用日本理学Ｄ／ｍａｘＲＡＸ射线衍射仪对其进行化合物定性分析,并介绍样品的采集与制样方法、仪器测试条件。最后通过ＪＣＰＤＳＩＣＤＤ（国际粉末衍射数据中心）标准数据库检索出该样品所含的全部化合物     

The in situ treatment of TCE and PFAS in groundwater within a silty sand aquifer

Chlorinated ethenes such as trichloroethene (TCE), cis‐1,2‐dichloroethene (cis‐1,2‐DCE), and vinyl chloride along with per‐ and polyfluoroalkyl substances (PFAS) have been identified as chemicals of concern in groundwater; with many of the compounds being confirmed as being carcinogens or suspected carcinogens. While there are a variety of demonstrated in‐situ technologies for the treatment of chlorinated ethenes, there are limited technologies available to treat PFAS in groundwater. At a former industrial site shallow groundwater was impacted with TCE, cis‐1,2‐DCE, and vinyl chloride at concentrations up to 985, 258, and 54 µg/L, respectively. The groundwater also contained maximum concentrations of the following PFAS: 12,800 ng/L of perfluoropentanoic acid, 3,240 ng/L of perfluorohexanoic acid, 795 ng/L of perfluorobutanoic acid, 950 ng/L of perfluorooctanoic acid, and 2,140 ng/L of perfluorooctanesulfonic acid. Using a combination of adsorption, biotic, and abiotic degradation in situ remedial approaches, the chemicals of concern were targeted for removal from the groundwater with adsorption being utilized for PFAS whereas adsorption, chemical reduction, and anaerobic biodegradation were used for the chlorinated ethenes. Sampling of the groundwater over a 24‐month period indicated that the detected PFAS were treated to either their detection, or below the analytical detection limit over the monitoring period. Postinjection results for TCE, cis‐1,2‐DCE, and vinyl chloride indicated that the concentrations of the three compounds decreased by an order of magnitude within 4 months of injection, with TCE decreasing to below the analytical detection limit over the 24‐month monitoring period. Cis‐1,2‐DCE, and vinyl chloride concentrations decreased by over 99% within 8 months of injections, remaining at or below these concentrations during the 24‐month monitoring period. Analyses of Dehalococcoides, ethene, and acetylene over time suggest that microbiological and reductive dechlorination were occurring in conjunction with adsorption to attenuate the chlorinated ethenes and PFAS within the aquifer. Analysis of soil cores collected pre‐ and post‐injection, indicated that the distribution of the colloidal activated carbon was influenced by small scale heterogeneities within the aquifer. However, all aquifer samples collected within the targeted injection zone contained total organic carbon at concentrations at least one order of magnitude greater than the preinjection total organic carbon concentrations.     

煤矿自燃火灾治理关键技术的研究与应用

介绍了使用同位素测氡法探测煤矿自燃火源位置的原理及应用效果。实践证明,该方法是解决煤矿自燃火灾治理难题的关键技术,由于投资少,精度高,软件处理直观可靠,它有重要推广价值     

雷管空中爆炸压力分布的理论计算

在对８＃ 雷管装药进行简化处理的基础上,其空中爆炸一定范围内的压力场分布可通过理论计算求得。近场参数可用自相似方法求解,而非近场参数又可用ＭａｃＣｏｒｍ ａｃｋ 两步格式对偏微分方程进行数值求解。将获得的压力场与实测结果进行比较,两者基本一致     

计算机辅助确定外因火灾位置方法

系统介绍用计算机辅助确定矿井外因火灾位置方法的原理,给出该方法的具体步骤,剖析其定性分析、定量分析和定量分析结果评价三大步骤中的各技术关键,并借助一个实例验证了该方法实用的可行性     

一种控制粮食工厂溜管噪声的简易措施

溜管噪声产生的原因是物料颗粒与溜管壁及物料颗粒之间相互撞击的结果,提出了降低噪声的简单措施,在溜管中安装缓冲箱和降速板可取得较好的降噪效果。     

化学纤维栅湿式过滤除尘的实验研究

化学纤维栅湿式除尘是一种复合机理的新型湿式过滤除尘技术,其过滤风速为2～10m/s,阻力仅为200～500Pa,除尘效率达到99.62％,能很好解决矿山溜井卸矿产生的粉尘,使溜井含尘气流经净化后达到新鲜风流卫生标准。     

促进企业安全文化系统化发展的思路

为了实现企业安全文化由低级向高级不断发展的目的 ,笔者提出 :应该在我国大力开展“企业安全文化促进计划 (ESCPP)”的研究和推广应用。ESCPP是一种有效促进企业安全文化持续发展而建立的系统化方法和工作体系。完整的ESCPP至少应该包括 :①建立科学合理的企业安全文化的评价指标体系 ;②利用评价指标体系对企业的安全文化现状进行评估 ;③确定企业安全文化发展的目标 ;④制定企业安全文化改进方案 ;⑤进行员工培训 ;⑥实施已制定好的企业安全文化改进方案 ;⑦评估改进方案实施效果 ,持续改进。笔者对ESCPP的这 7个方面进行了论述。