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61.
上海市郊大棚蔬菜农药污染防治对策   总被引:4,自引:0,他引:4  
在对上海市郊大棚农药污染的情况调查研究的基础上,指出了防治大棚蔬菜农药污染的必要性及其科学依据,并进而提出了具体的综合蔟上海市郊的农业生产中,使用高毒农药及具潜在“三致”作用的危险级、较危险级农药,加速引进使用高效低毒农药,特别是杀菌剂,合理控制药液浓度以降低大棚蔬菜中农药的残留量,并根据目标制定分步骤的具体实施计划。  相似文献   
62.
One of threatening buried steel pipeline in bad geological regions is collapsed rock. Buckling behavior of a buried pipeline impacted by a perilous rock with spherical shape was investigated by numerical simulation. Effects of pipeline parameters (internal pressure, wall thickness, diameter, buried depth) and perilous rock parameters (impact velocity, radius, eccentric distance) on deformation, stress and strain of the buried pipeline were discussed. Buckling behaviors of the buried pipeline under transverse and longitudinal inclined impacts also were studied. The results show that cross section shape of the buried pipeline becomes to an oval, then to a peach shape, and finally to a crescent shape or gourd shape in the process of rock’s impact. The deformation process of a buried pipeline can be divided into four stages. They are elastic deformation stage, buckling stage, elastic recovery stage and final deformation stage. Buckling mode of no-pressure pipeline is more serious than the pressure pipeline. The impact dent’s length and depth increase with the decreasing of buried depth, wall thickness and internal pressure. But they increase with the increasing of impact velocity, perilous rock’s radius and pipeline’s diameter. The maximum stress and plastic strain decrease with the increasing of buried depth and wall thickness. Under rock’s eccentric impact, impact dent trends to one side. Stress and plastic deformation decrease with the eccentric distance increases. Under rock’s transverse and longitudinal inclined impacts, cross section shape of the buried pipeline is an oval shape when the incidence angle α ≤ 45°, and there is no plastic deformation. When α > 45°, impact dent appears. Buckling is more serious with the incidence angle increases. Destructive powers of transverse and longitudinal inclined impacts are smaller than the vertical impact.  相似文献   
63.
Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, whereas glass packaging is the worst choice. The paper presents a scenario analysis varying both the method used for accounting for recycling as well as the recycling rates of the packaging materials. Changes in overall results with parameters analysis changing are calculated and highlighted throughout the paper. The impact of a reuse policy of the glass-based solution is also analysed; a model for disposable glass packaging is proposed and the obtained results are compared with the single use polypropylene and tin steel-based packaging. In order to analyse the impact of different End of Life scenarios on the present case study, collecting as well as recycling rates of some European countries have been used. The results revealed a significant fluctuation both in energy consumption and in CO2 emission as the nation changes. Summing up, a methodology for packaging environmental impact analysis is applied to a real case study, some crucial aspects of the methodology have been analysed in depth in order to give a contribution in packaging environmental impact analysis.  相似文献   
64.
包装印刷废水处理工程实践   总被引:2,自引:0,他引:2  
程凯英  刘备  邓耀杰 《环境工程》2005,23(5):32-33,36
针对包装印刷废水的水质特点,选择“预处理+A2+O”为主体的组合处理工艺。工程实践结果表明工艺合理、技术先进;出水水质达到《水污染物排放限值》(DB44/26-2001)中的一级标准。  相似文献   
65.
Fujima S  Ohura T  Amagai T 《Chemosphere》2006,65(11):1983-1989
An analytical method for the determination of gaseous and particulate chlorinated polycyclic aromatic hydrocarbons (ClPAHs) was investigated. By means of this method, concentrations and isomer profiles of the 27 target ClPAHs could be analyzed. To evaluate the usefulness of the method for analyzing ClPAH emissions, laboratory-scale scorching tests were performed on polyvinylidene chloride (PVDC) plastic wrap over a flame of the gas burner. Only seven of the target ClPAHs were detected, and all compounds detected had 2, 3, or 4 rings. The detected ClPAHs were present in both the particulate phase and the gaseous phase, but they were present at higher concentrations in the gaseous phase than in the particulate phase. Relationships between the number of chlorine substituents on the naphthalene/phenanthrene rings and the overall concentration and the percentage in the particulate phase were also investigated.  相似文献   
66.
弹药集装单元动力学试验研究   总被引:3,自引:1,他引:2       下载免费PDF全文
弹药集装单元是一种新型的弹药保障载具,没有具体的力学试验标准。通过研究弹药保障流程中的装卸与公路运输环境,分析可能出现的振动与冲击效应,参考相关弹药包装试验规程和试验方法,对弹药集装单元进行了相关动力学试验,进而评估弹药集装单元的力学性能,并证明弹药集装单元的设计可以满足弹药集装化保障的强度需求。  相似文献   
67.
Polyethylene terephthalate (PET) has become the most favourable packaging material world-wide for beverages. The reason for this development is the excellent material properties of the PET material, especially its unbreakability and the very low weight of the bottles compared to glass bottles of the same filling volume. Nowadays, PET bottles are used for softdrinks, mineral water, energy drinks, ice teas as well as for more sensitive beverages like beer, wine and juices. For a long time, however, a bottle-to-bottle recycling of post-consumer PET packaging materials was not possible, because of the lack of knowledge about contamination of packaging polymers during first use or recollection. In addition, the decontamination efficiencies of recycling processes were in most cases unknown. During the last 20 years, PET recollection as well as recycling processes made a huge progress. Today, sophisticated decontamination processes, so-called super-clean recycling processes, are available for PET, which are able to decontaminate post-consumer contaminants to concentration levels of virgin PET materials. In the 1991, the first food contact approval of post-consumer PET in direct food contact applications has been given for post-consumer recycled PET in the USA. Now, 20 years after the first food approval of a PET super-clean recycling process, this article gives an overview over the world-wide progress of the bottle-to-bottle recycling of PET beverage bottles, e.g. the recollection amount of post-consumer PET bottles and the super-clean recycling technologies.  相似文献   
68.
The impact of the management of packaging waste on the environment, economic growth and job creation is analyzed in this paper. This integrated assessment intends to cover a gap in the literature for this type of studies, using the specific case study of the Portuguese packaging waste management system (SIGRE).The net environmental benefits associated with the management of packaging waste, are calculated using the Life Cycle Assessment methodology. The results show that, for the categories studied, the impacts associated to SIGRE's various activities are surpassed by the benefits associated to material and energy recovery, with special focus on recycling. For example, in 2011 SIGRE avoided the emission of 116 kt CO2 equiv. – the equivalent carbon emission of the electricity consumption of 124.000 households in Portugal.The economic impact of SIGRE is evaluated through Input–Output Analysis. It was found that SIGRE's activities also have a significant economic impact. For example, their added value are ranked amongst the upper third of the economic activities with highest multiplier effect at national level: this means that for each Euro of value added generated within SIGRE, 1.25 additional € are added to the rest of the economy (multiplier effect of 2.25).Regarding the social impacts of SIGRE, the number of direct jobs associated with the system is estimated to be more than two thousand and three hundred workers. Out of these, 83% are connected to the management of municipal waste packaging (selective collection and sorting), 15% are connected to the management of non-municipal packaging waste and only 2% are connected to the Sociedade Ponto Verde (SPV, green dot society in English) – the management entity responsible for SIGRE.In general terms, the results obtained provide quantitative support to the EEA (2011) suggestion that moving up the waste hierarchy – from landfilling to recycling – creates jobs and boosts the economy.  相似文献   
69.
Plastic packaging wastes increased considerably in recent decades, raising a major and serious public concern on political, economical and environmental levels. Dealing with this kind of problems is generally done by landfilling and energy recovery. However, these two methods are becoming more and more expensive, hazardous to the public health and the environment. Therefore, recycling is gaining worldwide consideration as a solution to decrease the growing volume of plastic packaging wastes and simultaneously reduce the consumption of oil required to produce virgin resin. Nevertheless, a major shortage is encountered in recycling which is related to the sorting of plastic wastes. In this paper, a feasibility study was performed in order to test the potential of an innovative approach combining mid infrared (MIR) spectroscopy with independent components analysis (ICA), as a simple and fast approach which could achieve high separation rates. This approach (MIR-ICA) gave 100% discrimination rates in the separation of all studied plastics: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) and polylactide (PLA). In addition, some more specific discriminations were obtained separating plastic materials belonging to the same polymer family e.g. high density polyethylene (HDPE) from low density polyethylene (LDPE). High discrimination rates were obtained despite the heterogeneity among samples especially differences in colors, thicknesses and surface textures. The reproducibility of the proposed approach was also tested using two spectrometers with considerable differences in their sensitivities. Discrimination rates were not affected proving that the developed approach could be extrapolated to different spectrometers. MIR combined with ICA is a promising tool for plastic waste separation that can help improve performance in this field; however further technological improvements and developments are required before it can be applied at an industrial level given that all tests presented here were performed under laboratory conditions.  相似文献   
70.
The management of solid waste is changing. The traditional approach based on landfilling of mixed refuses is shifting toward a system based on the at-source sorting of waste into specific fractions. The biological treatment of the organic fraction is considered to be an appropriate form of disposal not only for the “traditional≓ feedstock such as food scraps and vegetable and garden waste, but also for biodegradable packaging, when not recyclable in other ways. Any change from a complex system to another is difficult since many factors are to be organized and optimized. Industry must develop and manufacture compostable products, municipalities must build composting plants and organize source-separated collection, and regulatory bodies must define widely acceptable criteria of compostability. In Europe, the European Union has assigned the last task to the CEN, to provide common criteria and avoid hindrance to commercial exchanges. In Italy the UNI, the national standardization organization, has produced a working document to contribute to the discussion on the European level. In this paper the UNI scheme is described. A condensed version of this paper was presented by one of the authors (F.D.I.) at the 5th annual meeting of the BEDP Society, held in Nashville, September 22–26, 1996, during a session covering International Standards for Biodegradation Testing.  相似文献   
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