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991.
The natural gas vehicle market is rapidly developing throughout the world, and the majority of such vehicles operate on compressed natural gas(CNG). However, most studies on the emission characteristics of CNG vehicles rely on laboratory chassis dynamometer measurements, which do not accurately represent actual road driving conditions. To further investigate the emission characteristics of CNG vehicles, two CNG city buses and two CNG coaches were tested on public urban roads and highway sections. Our results show that when speeds of 0–10 km/hr were increased to 10–20 km/hr, the CO_2, CO, nitrogen oxide(NO_x), and total hydrocarbon(THC) emission factors decreased by(71.6 ± 4.3)%,(65.6 ± 9.5)%,(64.9 ± 9.2)% and(67.8 ± 0.3)%, respectively. In this study, The Beijing city buses with stricter emission standards(Euro Ⅳ) did not have lower emission factors than the Chongqing coaches with Euro Ⅱ emission standards. Both the higher emission factors at 0–10 km/hr speeds and the higher percentage of driving in the low-speed regime during the entire road cycle may have contributed to the higher CO_2 and CO emission factors of these city buses. Additionally, compared with the emission factors produced in the urban road tests, the CO emission factors of the CNG buses in highway tests decreased the most(by 83.2%), followed by the THC emission factors, which decreased by 67.1%.  相似文献   
992.
生活垃圾焚烧炉渣富集了大量重金属,对环境有严重影响。对生活垃圾焚烧炉渣以( HJ/T 299-2007)硫酸硝酸法浸提,在不同的pH浸提条件下对炉渣中重金属浸出特性进行了实验研究。结果表明重金属浸出量随着浸出pH的下降有明显上升趋势,尤其在酸性条件下有明显提升。炉渣在酸雨长期浸泡下会浸出大量重金属,对周边土壤及地下水造成严重影响。  相似文献   
993.
环境监理是“三同时”制度全过程管理的体现.统一的行业收费标准对环境监理行业的健康发展至关重要.完善的收费机制有利于企业间的公平竞争,先进技术的应用与发展,高端人才的引进.通过对比发展较成熟的工程监理取费机制,分析环境监理的工作内容,收集已实施案例数据.通过matlab技术对收集的取费数据进行拟合分析,得出环境监理取费函数,并检验函数偏差.得出以投资额为基数的环境监理基价取费建议表.  相似文献   
994.
995.
This paper examines a transition of environmental governance in China that involves increased transparency and public participation. It pays close attention to the role of the mass media in this transformation. After briefly reviewing the history of environmental governance in China, the paper examines the particular transformations in the governance regime that are associated with the controversy over the sealing of the eastern lake in the Old Summer Palace, Beijing. The paper argues that the central government has increasingly enlisted the support of the public and the media in governing environmental matters and provides evidence that the traditional mass media and the Internet have become increasingly active in environmental debates in China.  相似文献   
996.
Experimental results indicated that ozone transfer in the rotating packed contactor was noticeably greater than in a traditional packed-bed contactor under similar operational conditions. Ozonation in the rotating packed contactor has been shown to be feasible for achieving nearly complete decomposition of o-cresol within 1 hour. The decomposition of o-cresol by ozonation in the rotating packed contactor increased with increasing rotor speed and decreasing the gas-liquid flowrate ratio. However, the reduction of total organic carbon during the ozonation of o-cresol was not influenced by variation of rotor speed and gas-liquid flowrate ratio. The species distribution of o-cresol under various solution conditions plays a significant role in determining the decomposition behavior. In most experiments conducted in this study, the decomposition of o-cresol by ozonation was more favorable under alkaline conditions.  相似文献   
997.
998.
党的十五大把环境保护问题作为基本国策,并强调:“正确处理经济发展同人口、资源、环境的关系”。这表明生态问题已经引起高度重视,建立和发展生态工业已成为当前一项重要任务。本文在介绍生态工业定义的基础上,说明了建立和发展生态工业的必要性及其如何建立和发展生态工业。  相似文献   
999.
安全防护鞋存不同作业场合穿用起着保护脚部、腿部免受伤害的作用。内包头鞋属于安全防护鞋的一种,是防御物体坠落伤害足趾的一种特殊功能鞋。  相似文献   
1000.
• MPs were analyzed throughout three WWTPs with mixed domestic–industrial influents. • White polyethylene granules from plastic manufacturing were the most dominant MPs. • MPs abundance in random grab-sampling was lower than that in daily dense sampling. • The production of MPs such as microbeads need to be restricted from the source. In wastewater treatment plants (WWTPs), microplastics (MPs) are complex, especially with mixed domestic–industrial influents. Conventional random grab sampling can roughly depict the distribution and characteristics of MPs but can not accurately reflect their daily fluctuations. In this study, the concentration, shape, polymer type, size, and color of MPs were analyzed by micro-Raman spectroscopy (detection limit of 0.05 mm) throughout treatment stages of three mixed domestic–industrial WWTPs (W1, W2, and W3) in Wuxi City, China, and the daily fluctuations of MPs were also obtained by dense grab sampling within 24 h. For influent samples, the average MP concentration of 392.2 items/L in W1 with 10% industrial wastewater was much higher than those in W2 (71.2 items/L with 10% industrial wastewater) and W3 (38.3 items/L with 60% industrial wastewater). White polyethylene granules with a diameter less than 0.5 mm from plastic manufacturing were the most dominant MPs in the influent of W1, proving the key role of industrial sources in MPs pollution. In addition, the daily dense sampling results showed that MP concentration in W1 influent fluctuated widely between 29.1 items/L and 4617.6 items/L within a day. Finally, few MPs (less than 4.0 items/L) in these WWTPs effluents were attributed to the effective removal of wastewater treatment processes. Thus, further attention should be paid to regulating the primary sources of MPs.  相似文献   
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