火灾环境下钢结构力学响应行为研究回溯与前瞻

火灾环境下高温对结构钢材的力学性能具有显著的不利影响.通常钢材在200～400℃的温度下力学性能开始下降,在800℃以上几乎丧失所有的强度.火灾环境下的钢结构力学响应行为是钢结构抗火设计的前提.为了展示火灾环境下钢结构的力学响应研究的清晰脉络,首先综述了火灾环境工况加载、钢结构升温规律的研究文献,然后从钢的耐火性能分析开始,评述了钢结构形式对耐火性能的影响和热作用下的结构变形研究.研究表明:若采用ISO 834标准升温曲线作为热加载方式,钢结构的升温规律和力学响应行为与真实火灾场景下相比差异显著,在标准火下钢的抗火时间更长;钢结构在火灾环境下的热应变随温度升高而增大,最终导致屈曲和过度挠度;当温度超过400℃时,高温蠕变会加速结构的失效;试验和数值模拟方法能很好地预测钢结构在真实火灾环境下的温升规律;较为真实地表征钢结构的不均匀力学响应行为,首先需要加载真实的火灾工况,同时要充分考虑钢结构形式,并耦合运用工程热物理、力学相关工具和方法;钢附着可燃材料燃烧的热反馈及相应的力学响应行为是钢结构抗火研究的新问题,针对该问题需要建立科学的热-力耦合工程定量测试方法.     

油田修井作业井场安全照明灯

油田修井作业井场传统的照明灯,一般是交流220 V大功率白炽灯泡或普通探照灯,这种传统的照明灯,为油田的修井作业井场照明发挥了作用,但其存在着亮度差、照射方位及角度有限、移动不便、安全性能差和耗电大的缺陷.     

小白菜对猪粪中高Cu和Zn的富集与转运

近年来,规模化养猪中Cu和Zn广泛应用于饲料添加剂,导致猪粪含大量的cu和Zn.猪粪土地利用中高Cu和Zn导致的环境污染和植物效应已引起了人们的高度关注.研究高Cu和Zn的猪粪施入土壤后典型蔬菜对Cu和Zn的富集和转运,可为有机蔬菜安全生产和品质提高提供科学依据,对粪便中重金属的健康风险评价具有重要的参考价值.本研究以...     

Evaluation of the infectivity, gene and antigenicity persistence of rotaviruses by free chlorine disinfection

The effects of free chlorine disinfection of tap water and wastewater effluents on the infectivity, gene integrity and surface antigens of rotaviruses were evaluated by a bench-scale chlorine disinfection experiments. Plaque assays, integrated cell culture-quantitative RT-PCR (ICC-RT-qPCR), RT-qPCR, and enzyme-linked immunosorbent assays (ELISA), respectively, were used to assess the influence of the disinfectant on virus infectivity as well as genetic and antigenic integrity of simian rotavirus SA11 as a surrogate for human rotaviruses. The ICC-RT-qPCR was able to detect rotaviruses survival from chlorine disinfection at chlorine dose up to 20 mg/L (60 min contact), which suggested a required chlorine dose of 5 folds (from 1 to 5 mg/L) higher than that indicated by the plaque assay to achieve 1.8 log₁₀ reductions in tap water with 60 min exposing. The VP7 gene was more resistant than the infectivity and existed at chlorine dose up to 20 mg/L (60 min contact), while the antigencity was undetectable with chlorine dose more than 5 mg/L (60 min contact). The water quality also impacted the inactivation efficiencies, and rotaviruses have a relatively higher resistant in secondary effluents than in the tap water under the same chlorine disinfection treatments. This study indicated that rotaviruses have a higher infectivity, gene and antigencity resistance to chlorine than that previously indicated by plaque assay only, which seemed to underestimate the resistance of rotaviruses to chlorine and the risk of rotaviruses in environments. Present results also suggested that re-evaluation of resistance of other waterborne viruses after disinfections by more sensitive infectivity detection method (such as ICC-RT-qPCR) may be necessary, to determine the adequate disinfectant doses required for the inactivation of waterborne viruses.     

Seedling growth and metal accumulation of selected woody species in copper and lead/zinc mine tailings

A greenhouse pot experiment was conducted to evaluate the potential of selected woody plants for revegetation in copper (Cu) and lead/zinc (Pb/Zn) mine tailing areas. Five woody species (Amorpha fruticosa Linn, Vitex trifolia Linn: var. simplicifolia Cham, Glochidion puberum (Linn.) Hutch, Broussonetia papyrifera, and Styrax tonkinensis) and one herbaceous species (Sesbania cannabina Pers) were planted in Cu and Pb/Zn tailings to assess their growth, root morphology, nutrition uptake, metal accumulation, and translocation in plants. Amorpha fruticosa maintained normal growth, while the other species demonstrated stress related growth and root development. Sesbania cannabina showed the highest biomass among the plants, although it decreased by 30% in Cu tailings and 40% in Pb/Zn tailings. Calculated tolerance index (TI) values suggested that A. fruticosa, an N-fixing shrub, was the most tolerant species to both tailings (TI values 0.92–1.01), while S. cannabina had a moderate TI of 0.65–0.81 and B. papyrifera was the most sensitive species, especially to Pb/Zn tailings (TI values 0.15–0.19). Despite the high concentrations of heavy metals in the mine tailings and plants roots, only a small transfer of these elements to the aboveground parts of the woody plants was evident from the low translocation factor (TF) values. Among the woody plants, V. trifolia var. simplicifolia had the highest TF values for Zn (1.32), Cu (0.78), and Pb/Zn (0.78). The results suggested that A. fruticosa and S. cannabina, which have the highest tolerance and biomass production, respectively, demonstrated the potential for tailings revegetation in southern China.     

上海市土地利用与生态服务价值变化研究

基于Costanza对生态系统服务价值理论的研究成果,结合谢高地等对中国陆地生态系统单位面积生态服务价值表,计算了2003—2007年间上海市生态系统服务价值变化情况和敏感性指数,03年-07年,生态服务价值减少了1．1亿元,各种土地利用方式的生态系统服务价值的敏感性指数均小于1,表明生态系统服务价值对价值系数的变化是缺乏弹性的。     

抚顺市分段降水化学研究

本文采用分段监测的方式研究了抚顺市分段降水化学组成及其变化特征。结果表明：抚顺市降水中阴离子以SO42-、NO3-为主,阳离子以Ca2＋、NH4＋为主。分段降水中,pH值和各离子浓度随着降水时间的持续呈下降趋势。通过分析同一场降水中不同离子之间的相关性可以推断,抚顺市酸雨有可能受局地污染而成。     

广西南宁发展燃料乙醇与节能减排的关系

摘要：根据生命周期评价,对燃料乙醇的节能和减排效果进行分析,依据发展规划,得出广西南宁发展燃料乙醇对节能减排的影响。结果表明,发展燃料乙醇将在节能和减排方面均产生积极作用,应加大在南宁乃至广西发展非粮燃料乙醇产业的力度。     

中国石化HSE管理系统建设及应用

结合中国石化HSE管理系统的建设情况,介绍了中国石化HSE管理系统建设的背景、系统总体架构、试点建设范围、系统功能及在试点企业的应用成效。     

CLP法规对我国实施GHS的启示

介绍了目前国内实施GHS的现状及面临的问题,通过分析《欧盟物质和混合物的分类、标签和包装法规》（CLP法规）的特点及其与GHS的异同,为我国实施GHS提出建议。