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151.
Minghui Xie Li Li Qi Qiao Qihong Sun Tichang Sun 《Journal of Cleaner Production》2011,19(17-18):2100-2106
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. 相似文献
152.
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。 相似文献
153.
Land-cover change in upper Barataria Basin estuary,Louisiana, 1972-1992: increases in Wetland area 总被引:1,自引:0,他引:1
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. 相似文献
154.
虚拟现实技术在安全工程中的应用 总被引:23,自引:2,他引:21
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 相似文献
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157.
从仪表设计及工效学问题的典型事故案例分析入手,提出人因化设计的基本理念,给出人机工程学的汽车仪表系统的基本要求及仪表显示装置人因化设计的基本原则、结构体系框图,提出了实现人因化设计的基本思路;探讨了在汽车仪表系统造型设计中如何体现中国元素与特色的途径;构建了汽车仪表设计中工效学评价体系模型。 相似文献
158.
高锰酸钾强化PAC混凝处理温瑞塘河黑臭水体试验研究 总被引:1,自引:0,他引:1
以浙江省温州市温瑞塘河某河段黑臭地表水为研究对象,考察高锰酸钾强化PAC混凝工艺的除污效能,获得处理温瑞塘河黑臭水体的最佳工艺条件,为恢复河流水体生态自净功能提供基础。试验结果表明,高锰酸钾的最优投加方式为在混凝剂PAC前投加,最佳预氧化时间5 min,最佳投加量1.5 mg/L。将本实验得出的最优混凝处理条件应用于温瑞塘河实际黑臭水体的处理时发现,处理后水质明显改善,此表明高锰酸钾强化混凝应急处理温瑞塘河黑臭水体是切实可行的,可为实际的应急处理工艺提供了理论依据和技术指导。 相似文献
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