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561.
清初“摊丁入亩”政策对清社会经济的恢复发展确实起到了促进作用,但同时对环境也构成了巨大威胁,引发了地表植被遭严重玻坏、自然灾害频繁、珍稀野生动植物大量灭绝等一系列环境问题。剖璞见玉,对今有史鉴作用。  相似文献   
562.
With increasing environmental issues and depleting resources, the effective application of green government procurement (GGP) is urgently needed and potentially can have greater impacts in the developing world rather than in the developed world. Such an approach can help promote the general goal of sustainable development and address environmental issues through purchasing and facilitating the use of environmentally friendly services and products. This paper addresses this issue by employing a case study on China. We first trace the development of the GGP concept, its spread to Asian countries, and a number of approaches used to expand GGP adoption. We then review current practices in China on GGP, and analyze and identify some of the current barriers and problems in promoting green procurement in the Chinese governmental sector. We finally seek to identify possible appropriate capacity-building solutions, in order to facilitate the application of GGP in China.  相似文献   
563.
提出了一个具有全新运转方式的新型RBC系统-回转升降生物接触工艺。通过清水充氧实验考查了实验装置的充氧能力;通过正交试验,确定了最佳运行条件;在最佳运行条件下,研究了本工艺处理有机废水的性能和效果。  相似文献   
564.
Industrial parks play a significant role in the production and use of goods and services. The proper management of solid waste is a major challenge for industrial parks due to the large quantity of wastes and the variability of waste characteristics from these types of developments. Therefore, integrated solid waste management has become very crucial to the industrial park managers. Such an approach requires industrial park managers to assess the overall use of resources, and to seek waste reduction, reuse and recycling opportunities both at the individual company level and among different tenant companies. The adoption of this method can bring both economic and environmental benefits. This paper introduces the planning efforts of a real case in China. It first presents the basic information on Tianjin Economic Development Area (TEDA), and then introduces its current practices on solid waste management. The main focus of this paper is to describe how to plan an integrated solid waste management system at TEDA. Benefits and challenges are all identified and analyzed. The experiences and methods from this case study should be applied in other industrial parks so as to improve the overall eco-efficiency of the whole industrial park.  相似文献   
565.
通过原位水质监测仪监测某石油类污染地下水的6项常规水化学指标,研究不同测量方式、不同测量深度对其产生的影响。结果表明:受石油污染的地下水水面以下0.5 m处,原、异位测量的水温、p H值、溶解氧、氧化还原电位、浊度均有不同程度的差异。在对比研究期内,可观测到这种差异最大可达:水温5~6℃,p H值0.2,溶解氧3.0 mg/L,氧化还原电位11 m V,浊度55 NTU。这种地下水环境条件的改变,必然会引起一系列水文地球化学、生物地球化学反应的变化。原位测量水深0.5~4 m范围内,水温随深度增加逐渐增大,最大变幅0.16℃;p H随深度增加变化不大;DO受温度和生化耗氧作用影响,随深度增加而降低;ORP与DO变化趋势大致相同,最大减幅达62 m V;电导率随地下水深度增加其值不变;最大浊度值113 NTU出现在水深4 m处。  相似文献   
566.
郭耕 《防灾博览》2004,(1):41-42
就目前所知,20世纪里没有哪种灵长类动物走向灭绝。这似乎是一个令人欣慰的记录,因为当今世界每天都有约100种物种在灭绝。可是,千万不要高兴太早,刚刚进入新世纪就有一种非洲疣猴灭绝了。可以说,包括人类在内的动物王国正日益面临生态环境全面退化的厄运。原因很简单,人的数量和人的欲望正在急剧增长,这使十余种人类的表亲,从  相似文献   
567.
This paper presents the findings from a study on the evaporation process of 93 RON (research octane number) unleaded gasoline. The parameters measured in the experiment included the weight, the RVP (Reid vapor pressure) and the viscosity of gasoline, the concentration of NMHC (non-methane total hydrocarbon) in the oil vapor and the concentration of the main vapor constituent. Results showed that the parameters changed significantly as evaporation processed. The weight loss reached 86.36% after 300 days and presented a logarithmic curve with time. The RVP decreased from 38 kPa to 9.6 kPa. The viscosity of gasoline increased from 8.6 × 10?4 Pa s to 1.51 × 10?3 Pa s. All the concentrations of NMHC and the main constituent of vapor decreased in varying amounts. Most of the changes might be attributed to the evaporation of volatile hydrocarbons.  相似文献   
568.
短链氯化石蜡(SCCPs)是碳链长度为10至13个碳原子的正构烷烃氯代衍生物。SCCPs具有持久性、生物累积性、长距离迁移能力、以及毒性作用。SCCPs已被《关于持久性有机污染物的斯德哥尔摩公约》增列为持久性有机污染物审查范围内,引起了全球关注。SCCPs在环境各介质及生物体内均有检出,近年来,在室内空气和灰尘中也检出了大量SCCPs,其已成为人体暴露的一个重要来源。本文就大气环境及室内空气与灰尘中氯化石蜡(CPs)的采样与分析方法、污染水平与来源,及人体暴露概况进行了综合阐释,以期为我国大气和室内环境中CPs的研究工作提供参考。  相似文献   
569.
Dielectrophoresis (DEP) process could enhance the removal the Cd2+ and Pb2+ with less absorbent. The removal rates of both Cd2+ and Pb2+ increased with the increase of voltage. The overall removal rate of Cd2+ and Pb2+ in the binary system is higher than that of Cd2+ or Pb2+ in the single system. DEP could cause considerable changes of the bentonite particles in both surface morphology and microstructure. Dielectrophoresis (DEP) was combined with adsorption (ADS) to simultaneously and effectively remove Cd2+ and Pb2+ species from aqueous solution. To implement the process, bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions. These particles were subsequently trapped and removed by DEP. The effects of the adsorbent dosage, DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes, which allowed us to determine the optimal experimental conditions. The high removal efficiency, 97.3% and 99.9% for Cd2+ and Pb2+, respectively, were achieved when the ions are coexisting in the system. The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy. Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.  相似文献   
570.
文章从现有杆管清洁设备的基本结构、工作原理、应用效果入手,分析了井下、井口、井场、车间4个环节15种杆管清洁生产技术的优缺点和适应性,同时引入技术成熟完备性指标,对每种杆管清洁生产技术作了定量评价,认为在施工中应综合考虑地层、井史、油田所处环境敏感性等影响因素,将其集成或组合使用,形成适合于不同类型油井的杆管清洁模式。建议继续加强井下泄油、油管内壁清洗、内防喷、井口防喷防溅等关键设备研发与完善,提高清洁生产技术的适应性、可靠性,以降低劳动强度,提高工作效率。  相似文献   
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