A comparative study on milk packaging using life cycle assessment: from PA-PE-Al laminate and polyethylene in China

A Life Cycle Assessment (LCA) approach was used to compare the environmental impacts in the life cycle of two milk packaging systems, PA-PE-Al laminate—a laminated foil made from paper, polyethylene and aluminum foil—and polyethylene. The data for the mass, energy fluxes and environmental emissions were obtained from published literature and from site investigations, for the two systems being analyzed for environmental impacts. The application of LCA using Eco-Indicator 99 has made the comparison of the environmental impacts of the two milk packages possible. The results of this LCA study are discussed and the results reveal that the composite packaging has a slightly higher environmental impact than the plastic one. In addition, the environmental impact of raw material extraction is the highest in all of the life cycle stages except for disposal. The environmental impact of composite packaging mainly comes from the fossil fuels, land use and respiratory inorganics categories, while the plastic packaging mainly comes from the fossil fuels category. However, the composite packaging has a greater environmental impact because it has not been well recycled and reused. This environmental impact could be decreased by developing the technology to separate out polyethylene and aluminum from the packaging.     

化工事故应急救援仿真演练系统的实施探讨

阐述了化工事故应急救援仿真的必要性及其国内外研究进展;提出整个系统的框架并设计系统开发过程的模型;分析了基于高层体系结构(HIA)的仿真系统的开发要点,给出参考开发工具,从而为整个系统开发提供思路.     

三叶鬼针草生物量分配与化感作用对大气温度升高的响应

全球气候变暖已经成为不容置疑的事实,同时外来入侵植物对入侵地的生态环境造成严重的危害,外来入侵植物可能对温度升高做出积极地响应。文章研究了不同温度(22、26和30℃)处理对入侵植物三叶鬼针草(Bidens pilosa L.)种子萌发、幼苗生物量分配及化感作用的影响,探讨三叶鬼针草对全球气候变暖的响应策略。结果表明;温度为22和26℃比30℃有利于三叶鬼针草种子的萌发。温度升高显著增加三叶鬼针草的株高、生物量和叶面积,三叶鬼针草幼苗增加对茎和叶的生物量投资。同时相同浓度的三叶鬼针草水浸提液对马唐(Digitaria sanguinalis(L.)Scop)和牛筋草(Eleusine indica(L.)Gaertn)的化感作用随着温度升高而增强。研究表明:温度升高促进了三叶鬼针草的生长,改变生物量分配模式同时增强了对受体植物的化感作用。温度升高可能是促进三叶鬼针草入侵的生态环境因子之一,未来全球气温变暖可能使其入侵加剧。     

GIS网络服务区分析在重庆市主城区夜间施工噪声投诉处置中应用

通过对重庆市主城区夜间施工噪声投诉处置现状分析,以主城区道路交通网络、环境监察机构分布等数据专题建模,采用G IS的网络服务区功能的分析结果,提出车辆调度合理化建议方案,为环境监察部门的夜间施工噪声投诉处置车辆部署调度提供辅助技术支持。     

贵州省野生生物资源开发利用与保护

本文论述了贵州省的野生生物资源概况，揭示了资源开发利用存在的问题，并对资源的开发利用与保护提出了建议。     

Land-cover change in upper Barataria Basin estuary,Louisiana, 1972-1992: increases in Wetland area

The Barataria Basin, Louisiana, USA, is an extensive wetland and coastal estuary system of great economic and intrinsic value. Although high rates of wetland loss along the coastal margin of the Barataria Basin have been well documented, little information exists on whether freshwater wetlands in the upper basin have changed. Our objectives were to quantify land-cover change in the upper basin over 20 years from 1972–1992 and to determine land-cover transition rates among land-cover types. Using 80-m resolution Landsat MSS data from the North American Landscape Characterization (NALC) data archive, we classified images from three time steps (1972, 1985, 1992) into six land-cover types: agriculture, urban, bottomland hardwood forest, swamp forest, freshwater marsh, and open water. Significant changes in land cover occurred within the upper Barataria Basin over the study period. Urban land increased from 8% to 17% of the total upper basin area, primarily due to conversions from agricultural land, and to a lesser degree, bottomland forest. Swamp forest increased from 30% to 41%, associated with conversions from bottomland hardwood forest and freshwater marsh. Overall, bottomland forest decreased 38% and total wetland area increased 21%. Within the upper Barataria, increases in total wetland area may be due to land subsidence. Based on our results, if present trends in the reduction of bottomland forest land cover were to continue, the upper Barataria Basin may have no bottomland hardwood forests left by the year 2025, as it is subjected to multiple stressors both in the higher elevations (from urbanization) and lower elevations (most likely from land subsidence). These results suggest that changes in the upper freshwater portions of coastal estuaries can be large and quite different from patterns observed in the more saline coastal margins.     

广东省火电厂烟气脱硫装置的经济技术分析

简要介绍了广东省7个火电厂现有的5种烟气脱硫技术装置：海水脱硫、荷电干式烟气脱硫、湿式石灰石／石膏法烟气脱硫、DCL燃煤固硫剂脱硫及烟气循环流化床脱硫技术，对它们的经济、技术性进行了分析比较。     

城市污水厂污泥浓缩新技术的应用

分析了新型污泥浓缩设备的技术经济优点,现行污泥浓缩池的缺点、城市污水处理新工艺对浓缩的要求,介绍了2类污泥浓缩机在城市污水厂的选用和运行实例.     

基于小波包分析的爆破振动危害评价初探

结合振动主频的质点振速判据是对单一质点振速判据的补充和完善.但该判据的振动主频是通过FFT变换的频谱分析的方法获得的,不能体现爆破振动波形的多主振频带特征,而且由于方法本身的局限性使得主振频率发生的时间段不能确定.小波包分析法则克服了FFT频谱分析的局限,有效地分解和重构原始信号中的细节信号,并将其作为评价不同频率细节信号的爆破振动危害效果的基础.本文针对爆破振动的小波包分析法进行了研究,对各小波包细节信号加载条件下的不同危害效果进行了讨论,得到了相应的质点振速判据,并将该方法所得到的判据与FFT变换的频谱分析方法所得到的判据进行了对比.结果表明,基于小波包分析法的质点振速判据更加符合爆破振动危害的真实情况.     

虚拟现实技术在安全工程中的应用

论述了虚拟现实技术（ＶｉｒｔｕａｌＲｅａｌｉｔｙ）的基本原理、应用范围。结合大空间公用建筑火灾虚拟现实系统,提出了安全工程中应用虚拟现实技术的基本结构及程序设计关键技术,给出了大空间公用建筑火灾虚拟现实系统编制实例