绿色大学建设中的生态足迹

生态足迹分析法是评价绿色大学建设水平最好的指标之一.生态足迹分析法有综合法和成分法2种.本文简要介绍了生态足迹成分法的基本原理和算法,并以东北大学为例将该方法应用大学校园的研究.结果表明,东北大学2003年的生态足迹为24787hm2,即需要约25000hm²的生态生产性土地支持学校的各类消费并吸纳所产生的废弃物.其生态效率(即单位生态生产性土地可支持的学生数)为0.94人·hm^-2.生态足迹中,能源消费的足迹最大,占总足迹的2/3多;食物消费和固态垃圾次之,分别占总足迹的21.9%和5.7%.     

废旧电路板的组成与解离特性研究

废旧印刷电路板是电子废弃物的重要组成部分,含有大量金属、玻璃纤维增强树脂、塑料等有回收利用价值的组分,但处理不当会产生严重污染。在分析中,对细碎到粒度为5mm以下的废旧电路板物料中有价资源的赋存状态和解离特性进行了系统的研究,发现金属与非金属的基本解离粒度为1 2mm,解离度为55. 51%;塑料与其他金属(除铜、铁外)是0. 5mm以上废旧电路板物料中的主要组分,树脂与铜是0 .5mm以下物料中的主要组分;物料中平均金属含量为23. 80%,平均铜含量为5. 78%。     

COMPARISON OF PARAMETRIC TAIL ESTIMATORS FOR LOW‐FLOW FREQUENCY ANALYSIS1

ABSTRACT: In recent years, several approaches to hydrologic frequency analysis have been proposed that enable one to direct attention to that portion of an overall probability distribution that is of greatest interest. The majority of the studies have focused on the upper tail of a distribution for flood analyses, though the same ideas can be applied to low flows. This paper presents an evaluation of the performances of five different estimation methods that place an emphasis on fitting the lower tail of the lognormal distribution for estimation of the ten‐year low‐flow quantile. The methods compared include distributional truncation, MLE treatment of censored data, partial probability weighted moments, LL‐moments, and expected moments. It is concluded that while there are some differences among the alternative methods in terms of their biases and root mean square errors, no one method consistently performs better than the others, particularly with recognition that the underlying population distribution is unknown. Therefore, it seems perfectly legitimate to make a selection of a method on the basis other criteria, such as ease of use. It is also shown in this paper that the five alternative methods can perform about as well as, if not better than, an estimation strategy involving fitting the complete lognormal distribution using L‐moments.     

基于CiteSpace的城市空间形态与碳排放关系研究进展

城市空间形态与碳排放的关系是低碳城市建设的理论依据。基于WOS和CNKI数据库，采用CiteSpace软件对1991—2022年城市空间形态与碳排放的关系进行了综述。从发文趋势、合作网络、突现词探测、关键词分析等角度，分析了该领域的发展动态、研究热点，并通过关键词聚类对文献相关内容进行综合解析。结果表明：（1）1991—2022年该领域发文量总体呈上升趋势，在国际重要事件节点上，发文量有大幅上升。（2）中国是该领域发文最多的国家，发文量达34.03%，美国发文中心性最高，为0.48，且国家、机构合作紧密。（3）关键词共现表明探究城市形态对碳排放的影响一直是学术界关注的热点；突现词探测表明研究重心逐渐从与交通碳排放相关的城市空气质量转移到与城市形态和碳排放有关的内容上来。（4）从关键词聚类标签来看，国内外将城市碳排放测算作为重中之重，并通过指标量化城市空间形态分析城市形态对碳排放的驱动作用；通过建立模型定量探讨城市空间形态与碳排放的关系是未来的研究趋势。未来应编制规范的城市层面碳排放清单以提高测算精度、拓宽城市形态与碳排放关系的研究尺度、深入挖掘三维城市空间形态与碳排放的关系。     

能源流视角下村落尺度能源消费结构比较及环境效应研究：基于河南省邑西里村、杨家村及山东省东桥头村的调查分析

加强村落尺度能源消费活动及其环境效应研究是实现农村能源可持续转型及绿色发展精细化治理的前提。但目前该领域存在明显知识空白，其原因在于缺乏基础数据和系统化数据采集体系及集成分析方法。基于对河南省邑西里村、杨家村以及山东省东桥头村的实地调研和半结构式访谈，采用定性和定量结合的方法开展能源消费活动及环境效应比较研究。结果表明：（1）村落尺度能源消费具有显著空间分异特征。邑西里村、杨家村和东桥头村人均能源消费量分别为505 kgce、889 kgce和1139 kgce；由能源消费产生的温室气体与污染物的种类分别为CO₂、CH₄、SO₂、N₂O、NO_x和TSP，单个家庭CO₂的产生量在2000—4000 kg；CH₄、SO₂、TSP和NO_x的排放量基本在1—5 kg；N₂O的排放量均在100 g以下。（2）居民生活环境和炊事供暖是影响村域能源消费的主要因素。其在邑西里村、杨家村和东桥头村的总用能占比分别为50.10%、79.08%和77.61%。（3）能源来源及消费结构具有明显的区位属性特征。杨家村距离市区较近，天然气成为当地居民的主要来源；邑西里村和东桥头村离市区较远，则以电力和煤炭为主。未来乡村地区的发展应该与当地的地域特征相结合，构建具有地方化特征的发展策略，实现农村能源的低碳健康发展。     

企业碳信息披露质量评价及影响因素研究

科学有效地评价企业的碳信息披露质量并探寻影响碳信息披露的主要因素，有助于进一步提升企业的碳信息披露质量水平、发挥企业在我国如期实现碳达峰及碳中和进程中的积极作用。基于碳信息披露的四个维度构建制造业企业碳信息披露质量的评价体系，综合主成分分析法和熵权法测度我国制造业企业2018—2020年真实的碳信息披露质量水平及变化趋势，有效降低评价指标的维数，避免单一熵权法权重失真情况，并通过随机森林回归识别各个指标对企业碳信息披露质量的重要性。研究发现：（1）主成分和熵权法组合可有效降低信息量少的“干扰”维度对企业碳信息披露的影响，能客观真实地评价我国制造业企业的碳信息披露质量，从而获得比传统单独采用单一方法更有效的评价结果。（2）2018—2020年，我国制造业企业的碳信息披露质量整体呈现上升趋势且2020年的碳信息披露质量水平提升最大。（3）我国制造业企业的碳信息披露质量整体偏低，不同企业间的碳信息披露质量存在较大差异。（4）企业的研发投入、总资产、总负债等因素对企业碳信息披露质量有较大影响。     

Factors Affecting Take-up of and Drop-out from Home Composting Schemes

This paper reports survey results from Scotland and north-west England into home composting attitudes and behaviours. The results concentrate on: the take-up of home composting through promotional campaigns; and the reasons for drop-out. Motivations for take-up were balanced between environmental and gardening reasons, although capital cost was an important issue for some. Drop-outs occurred mainly through participants moving house or because of lack of success in producing compost. Few of those experiencing problems sought help. Those that did favoured official or professional sources. Neighbourhood social pressures to compost were relatively weak. The results are discussed in terms of the sustainability of home composting behaviour and the manage ment interventions that might be required in sustaining that behaviour.     

Renal tubular dysfunction caused by dietary hexachlorocyclohexane (HCH) isomers

Abstract

Dietary administration of β‐ and α‐hexachlorocyclohexane (HCH) to albino rats caused an abnormal excessive excretion of glucose in the urine, blood glucose level being nearly normal. Occurrence of glucosuria was also accompanied by increased excretions of the two low‐threshold compounds ‐ creatinine and urea, their levels in blood being normal. The interference of HCH isomers with renal function as evidenced by biochemical data was also indicated by histopathological lesions observed in the kidney sections, viz., hypertrophy and degeneration of the renal tubular epithelia.     

Performance studies of a low heat rejection engine operated on non-volatile vegetable oils with exhaust gas recirculation

During recent decades, considerable effort has been expended world-wide to reduce dependency on petroleum fuels for power generation and transportation through the search for suitable alternative fuels that are environmentally friendly. In this respect, vegetable oils are a promising alternative to diesel fuel. However, the high viscosity, poor volatility and cold flow characteristics of vegetable oils can cause some problems such as injector coking, severe engine deposits, filter gumming and piston ring sticking and thickening of lubrication from long-term use in diesel engines. These problems can be eliminated or minimised by transesterification of the vegetable oils to form monoesters. Although transesterification improves the fuel properties of vegetable oil, the viscosity and volatility of biodiesel are still worse than those of petroleum diesel fuel. The performance of a diesel engine with such biodiesel operation can be improved further with the concept of the low heat rejection (LHR) engine. In the LHR engine, combustion surfaces on the pistons, cylinder walls and valves can be coated with ceramic materials. The objective of this study was to apply the LHR engine concept for improving engine performance when either honge biodiesel, known as honge oil methyl ester (HOME), or neem biodiesel, known as neem oil methyl ester (NOME) oils was used as an alternative fuel. For this purpose, experiments were conducted on a single cylinder, four-stroke, direct injection, water-cooled compression ignition engine using diesel, HOME and NOME oils at different injection timings of 19, 23 and 27° before top dead centre (BTDC) with and without the induction of exhaust gas recirculation (EGR). The percentage of EGR was varied from 5 to 20% in steps of 5%. The results showed that specific fuel consumption and brake thermal efficiency were improved for both of the biodiesel fuels in the LHR engine. An EGR of 10% resulted in better performance with trade-off between oxides of nitrogen and hydrocarbons/carbon monoxide emissions and hence 10% EGR is taken as the best of the range from 5 to 20%. However, readings with other EGR ratios are not reported.     

低透突出煤层深孔水力致裂增透与浅孔抽采联合消突技术应用

为提高低透突出煤层的瓦斯抽采效果,在薛湖煤矿2303风巷进行了深孔水力致裂与潜孔抽采联合消突技术的试验应用.首先结合现场实际情况,从注水压力、钻孔布置和现场施工等方面研究了施工技术工艺,然后从应力分布、瓦斯解吸速度、钻屑瓦斯解吸指标、瓦斯抽采浓度等方面考察了水力致裂增透效果和联合消突技术的消突效果.应用表明,深孔水力致裂增透与浅孔抽采联合消突技术,工作面前方支承压力、瓦斯解吸速度、钻屑瓦斯解吸指标均大幅降低,瓦斯抽采浓度明显提高,抽采效果明显,为同类矿井的防突工作提供了可借鉴的技术和经验.