公共资源可持续利用的微观影响因素分析

草地被称为世界性的公共资源。以往对于草地退化的关注多侧重在技术研究和推广上。为揭示微观行为对公共资源利用的影响,以寻求有效途径保护具有重要生态战略意义的草地资源,论文利用2005年西部6省区17县231个农户数据以及2006和2007年环青海湖地区的实地调查经验,采用农户模型和计量分析方法,研究现有产权制度下牧民的草地管理行为对草地资源退化的影响。结果表明,牧民参与非农就业、扩大牧户的草场规模以及进行围栏和舍棚建设有利于减轻草场的退化。据此,提出以下政策建议:目前政府提供围栏和舍棚建设方面的相关政策扶持,同时,制定有利于牧民参与非农就业机会的政策,降低牧区的人口压力,可有效促进草地公共资源的可持续利用。     

市政垃圾焚烧飞灰中添加CaO抑制PCDD/Fs生成试验探究

采用自制装置,以CaO作为PCDD/Fs生成抑制剂,对市政垃圾焚烧飞灰做热处理。通过试验考察温度、CaO添加量等因素对飞灰中PCDD/Fs生成的影响。结果表明：质量分数为5%的CaO添加可以减少80%的PCDD/Fs生成。     

预处理方法对水葫芦厌氧发酵产沼气的影响

水葫芦可作为厌氧发酵产沼气的原料。研究发现,水葫芦自身的生物特性会制约其产气潜力的发挥,而发酵前预处理有助于解决这一问题。以采自昆明滇池的新鲜水葫芦为研究对象,分别采用物理法(切分法、压榨法),化学法(酸处理法、碱处理法和金属离子处理法)和生物法(酶处理法)对其进行预处理,以预处理后的水葫芦为原料进行发酵产沼气实验。结果表明,金属离子处理的原料产气效果最佳,在中温35℃,进样浓度7.4%(TS)时,其原料TS产气率、平均甲烷浓度和原料容积产气率分别为744.55 m3/t、59.32%和0.144 m3/(m3·d),与切分处理原料相比提高了88%、13%和87%。其余处理方法也在不同程度上优化了水葫芦的产气效果。因此,以预处理的方式来提高水葫芦的生物利用率和产气效率是可行的。     

Non-transport household energy consumption in Adelaide and Melbourne

The residential sector is the third largest sector of final energy use in Australian urban areas, accounting for about 12% of the country's total final energy consumption. What are the main determinants of energy consumption in the residential sector? This paper sheds light on this question by examining non-transport summer household energy consumption in Adelaide and Melbourne. Data were collected from a survey of 200 sample households and modelled according to a conceptual framework that not only emphasises household characteristics and housing stock characteristics but also controls the macro-environment factors. The findings reveal distinctive results in Adelaide and Melbourne. In Adelaide, household characteristics are the most important contributors in explaining non-transport household energy consumption. In Melbourne, the household characteristic as represented by income is important, but housing stock characteristics provide even more explanatory power. These findings contribute to the understanding of the factors that shape residential energy consumption and have policy implications in targeting household energy savings.     

BLR厌氧反应器处理垃圾焚烧厂渗滤液工程运行效能

采用1 100 m3BLR(biogas-lift reactor)厌氧反应器对垃圾焚烧厂渗滤液进行工程化处置,接种污泥为消化污泥,正常运行温度控制在(33±2)℃,启动负荷为1 kg COD/(m3·d),120 d后容积负荷达到10 kg/(m3·d)并稳定运行,出水COD浓度为4 500~6 500 mg/L,COD去除率为88%~92%,出水VFA含量为200~600 mg/L,p H值稳定在7.4~7.7,出水SS含量为1 000 mg/L左右,并可观察到沉降性较好的颗粒化污泥。反应器运行初期将VFA/ALK控制在1.6以内,系统并未因VFA积累而酸化崩溃,运行后期VFA/ALK值小于0.3,系统稳定运行。运行过程中进水氨氮浓度从400 mg/L升高到2 200 mg/L,未发现氨氮对厌氧生物处理的明显抑制现象。垃圾渗滤液中平均每去除1 kg COD产生沼气量为0.32 m3。     

Effect of PCM on temperature fluctuation during the door opening of a household refrigerator

Temperature fluctuation inside the cabinet of a household refrigerator significantly affects the quality of preserved food. Phase change material (PCM) is a latent heat storage system that can store and release the heat energy by changing its phase from liquid to solid and solid to liquid respectively. Therefore, use of PCM inside the refrigerator cabinet has the potential for minimizing the temperature fluctuation during the door opening and the power failure. However, very few studies in the literature were dedicated to investigating the role of PCM to reduce the temperature fluctuation. The aim of this work is to experimentally investigate the effects of PCM on temperature fluctuation inside the cabinet of a household refrigerator during the door opening and power failure. The results found that a significantly lower temperature fluctuation can be obtained using PCM. It was found that during the door opening condition the air temperature in the cabinet rose rapidly. However, when a PCM container was used, temperature variation was reduced to 3–5°C. During the power failure, the system with PCM maintained a lower temperature inside the storage chamber for a long period of time (about 2 hours). Moreover, the test results indicate that PCM maintains more stable temperature in the foodstuffs inside the refrigerator. This reduction of temperature fluctuation ultimately improves the quality of preserved food.     

Connecting environmental management and farm household livelihoods: The Rural Environment Protection Scheme in Ireland

This paper presents the relationship between an environmental protection scheme, established in Ireland in 1994 under EU Regulation No. 2078/92, and the livelihoods of Irish farm households. It explores this relationship within the framework of the new policy environment for EU agriculture and rural areas as set out in Agenda 2000. At the centre of this new policy environment is the European model for agriculture, embodying the concept of multifunctionality, which recognizes the pivotal position of an evolving agricultural sector in enhancing the viability of rural areas through broadening the assets of farm families. Research undertaken with farm households in the west of Ireland indicates a positive relationship between the Rural Environmental Protection Scheme and the economic and natural assets upon which they build their livelihoods. The case of a small-scale dairy farm household is presented, showing clearly the positive impact of the scheme, while also highlighting the vulnerability of these improvements. A major challenge facing policy-makers is the extent to which acceptable levels of income and an enhanced natural environment on such farms can be sustained. The position of advisory and research institutions in strengthening human capacities on farms is highlighted and their enhanced role is suggested in order to give meaning to multifunctional and sustainable agriculture within the context of rural area viability. Copyright © 2001 John Wiley & Sons, Ltd.     

北京市废旧家电产生量预测及回收体系规范化研究

随着技术水平提升及生活水平的提高,家电产品的更新换代也越来越快,废旧家电的末端治理问题亟待优化。以北京市为例,运用等维灰数递补动态预测方法研究4类主要家电的销量,发现自2010年起,北京市的家电销售量迅猛增长,并在此基础上预测了2013--2016年废旧家电的产生量,并就规范当前回收体系提出可行一性建议。     

农户经营行为对农村生态环境影响研究

农户生产经营行为关系到生产资源的合理利用与配置,影响到农村生态系统保护及其可持续发展。本研究以武汉城市圈及长株潭城市群内的650个农户为有效样本,分析了农户经营行为对农村生态环境及其五种表现形式的影响。结果表明:①劳动力投入行为中收入来源、家庭人均收入对农业面源污染有显著负面影响,家庭常住人口、家庭人均年收入对生活垃圾污染分别有显著正、负面影响;②农户文化程度越高,越能认识到农村生态环境污染问题;③经营规模越大,农业面源污染越严重,而对其它四类表现形式影响不显著;④农业投资力度越大,为提高产量而会造成越严重的农业面源污染及水质污染;⑤农户经营组织行为中,有机肥施用行为会造成农业面源污染,这些未施用的有机肥又会加剧生活垃圾污染,而且有机肥使用越多,农业面源污染及水质污染也就变弱。另外,参加技术培训会降低农业面源污染和水质污染。可见,农户经营行为更多地是在影响农村生态环境中的农业面源污染、水质污染及生活垃圾污染,对空气噪音污染及工业转嫁污染的影响并不明显。     

粮食补贴政策与农户非农就业行为研究

粮食补贴政策旨在提高农民种粮积极性,促进粮食增产和农民增收,随着国家粮食补贴资金投入力度的逐年加大,农民种粮积极性不断提高,家庭劳动时间分配很可能因此而产生调整。本文首先通过构建嵌入粮食补贴政策的农户劳动分配决策行为模型,理论分析粮食补贴政策对农户非农就业行为的影响,然后基于粮食主产区安徽省农户的实地调查数据,采用Tobit模型分析方法,实证分析粮食补贴政策对农户非农劳动时间供给的影响。研究结果显示:粮食补贴政策对农户非农劳动时间供给具有显著的负面影响,一定程度上有助于调动农民从事农业和粮食生产的积极性;然而,在农业内部工资率低于非农均衡工资率的情况下,这种由粮食补贴政策诱发的农户劳动就业行为变化对家庭经济收入的负面影响将超过当前的转移支付水平;若粮食补贴政策旨在稳定或增加农民收入,那么当前的补贴政策需要进行根本性调整。