Linkages between measures of biodiversity and community resilience in Pacific Island agroforests

Designing agroecosystems that are compatible with the conservation of biodiversity is a top conservation priority. However, the social variables that drive native biodiversity conservation in these systems are poorly understood. We devised a new approach to identify social–ecological linkages that affect conservation outcomes in agroecosystems and in social‐ecological systems more broadly. We focused on coastal agroforests in Fiji, which, like agroforests across other small Pacific Islands, are critical to food security, contain much of the country's remaining lowland forests, and have rapidly declining levels of native biodiversity. We tested the relationships among social variables and native tree species richness in agroforests with structural equation models. The models were built with data from ecological and social surveys in 100 agroforests and associated households. The agroforests hosted 95 native tree species of which almost one‐third were endemic. Fifty‐eight percent of farms had at least one species considered threatened at the national or international level. The best‐fit structural equation model (R² = 47.8%) showed that social variables important for community resilience—local ecological knowledge, social network connectivity, and livelihood diversity—had direct and indirect positive effects on native tree species richness. Cash‐crop intensification, a driver of biodiversity loss elsewhere, did not negatively affect native tree richness within parcels. Joining efforts to build community resilience, specifically by increasing livelihood diversity, local ecological knowledge, and social network connectivity, may help conservation agencies conserve the rapidly declining biodiversity in the region.     

废弃油基钻井液资源回收与无害化处置

废弃油基钻井液是钻井作业完成后产生的固体废物,因含有矿物油和柴油等,属于国家危险废物,成为制约油田清洁生产的一个技术难题.针对废弃油基钻井液的特点,经大量室内试验和多种处理方案的筛选,开发出了废弃油基钻井液资源回收与无害化处置技术.在废弃油基钻井液中加入收油剂,回收有用的油类.在收油后的剩余泥渣和产生的废水中分别加入无害化处理剂和絮凝剂,进行回用和无害化处理.油回收率可达90%以上,回收的油品质量达到《车用柴油》(GB/T 19147—2003)规定的-10#车用柴油技术要求;无害化处理后的泥渣浸出液中石油类,COD_Cr和重金属等污染物指标均低于《污水综合排放标准》(GB 8978—1996)二级标准限值;处理后的废水达到《污水综合排放标准》(GB 8978—1996)要求.      

电子废物资源化循环转化过程与代谢规律研究

选择废印刷电路板和废CRT玻壳玻璃的资源化过程作为承载实体,进行了研究分析.建立了电子废物资源化技术过程的物质能量转化模型;分析了废印刷电路板和废CRT玻壳玻璃的资源化过程中的物质流、能量流、废物流以及污染物的释放与迁移;核算了物质、能量转化清单.分析结果表明,废印刷电路板资源化过程中的分选环节能耗较高,达100kW×h/t,而拆解和非金属材料的热压成型是控制污染物排放的重点环节;废CRT玻壳玻璃资源化过程中屏玻璃和锥玻璃的再利用环节能耗较高,利用屏玻璃制造泡沫玻璃和锥玻璃冶炼铅的能耗分别为600, 250kW×h/t,破碎、研磨、锥玻璃冶炼铅是控制污染物排放的重点环节.     

Comparison and ranking of different modelling techniques for prediction of site index in Mediterranean mountain forests

Forestry science has a long tradition of studying the relationship between stand productivity and abiotic and biotic site characteristics, such as climate, topography, soil and vegetation. Many of the early site quality modelling studies related site index to environmental variables using basic statistical methods such as linear regression. Because most ecological variables show a typical non-linear course and a non-constant variance distribution, a large fraction of the variation remained unexplained by these linear models. More recently, the development of more advanced non-parametric and machine learning methods provided opportunities to overcome these limitations. Nevertheless, these methods also have drawbacks. Due to their increasing complexity they are not only more difficult to implement and interpret, but also more vulnerable to overfitting. Especially in a context of regionalisation, this may prove to be problematic. Although many non-parametric and machine learning methods are increasingly used in applications related to forest site quality assessment, their predictive performance has only been assessed for a limited number of methods and ecosystems.In this study, five different modelling techniques are compared and evaluated, i.e. multiple linear regression (MLR), classification and regression trees (CART), boosted regression trees (BRT), generalized additive models (GAM), and artificial neural networks (ANN). Each method is used to model site index of homogeneous stands of three important tree species of the Taurus Mountains (Turkey): Pinus brutia, Pinus nigra and Cedrus libani. Site index is related to soil, vegetation and topographical variables, which are available for 167 sample plots covering all important environmental gradients in the research area. The five techniques are compared in a multi-criteria decision analysis in which different model performance measures, ecological interpretability and user-friendliness are considered as criteria.When combining these criteria, in most cases GAM is found to outperform all other techniques for modelling site index for the three species. BRT is a good alternative in case the ecological interpretability of the technique is of higher importance. When user-friendliness is more important MLR and CART are the preferred alternatives. Despite its good predictive performance, ANN is penalized for its complex, non-transparent models and big training effort.     

线路板粉末风选过程气固两相流模拟及实验

针对线路板破碎粉末的特点,提出了一种通过风力分选实现废旧线路板中金属和非金属分离的方法.分别采用RNG k-ε模型、颗粒轨道模型模拟气流场和固体颗粒,模拟结果显示风选器腔体处于旋风状态,风压随着风选器半径和高度的增加而升高,至风选器高度为1.2m附近达到峰值.开展线路板粉末风选实验,通过模拟分析和实验分别得到不同粒径、不同叶轮转速下的优化工艺参数,结果表明粒级对实验结果的影响最大,当线路板粉末粒径为0.125~0.212mm、叶轮转速为200r/min时,金属回收率最高达到96.5%.最后进行分选效果的实验-模拟对比分析,验证了模拟的有效性及分选方案的可行性.     

高密度澄清池除氟中试研究

以聚合氯化铝为混凝剂,采用高密度回流絮凝澄清池进行饮用水除氟试验。考察了原水水量、氟初始浓度、原水浊度、絮体回流比等因素对除氟效果的影响。结果表明:高密度澄清池具有良好的除氟效果,可使滤后水中氟浓度低于1 mg/L。当絮体回流点位于快速混合处时,回流比为50%时,能提高氟的去除率。     

Practices,attitudes and motives for domestic waste recycling

SUMMARY

Solid household waste management in Malaysia has reached a critical stage. Increasing population, urbanization and changing patterns of lifestyle have instigated the phenomenon. The 15 000 tonnes of garbage produced daily are thrown into 230 landfills nationwide, where 80% of them have only two years of life span left. Although recycling programmes were launched as early as 1990, only 5% of the wastes are recycled. The purpose of the present research was to ascertain the current management of household solid waste, attitude and motivational factors towards recycling. Data were collected using interview survey on 150 households in an urban residential area. The findings demonstrated that the respondents had very low awareness and knowledge regarding local domestic waste management. Separation of organic and non-organic wastes was rarely practised by 76% of the respondents. Most waste was thrown away, except for newspaper and aluminium cans which were regularly recycled, while furniture, and electrical items were reused by giving away or trading-in. The attitude of the respondents towards recycling was modest. Of the five motivational factors, intrinsic satisfaction and individual commitment were more important reasons for recycling than convenience, economic motivation and societal commitment. The results of the study indicated that, in order to overcome the solid waste crisis, the conscience of the individual needs to be raised through environmental awareness and concern, inculcation of sustainable consumption practices and education on waste management.     

Sustaining recycling: identification and application of limiting factors in kerbside recycling areas

SUMMARY

Levels of recycling in the UK are substantially poorer than other European countries and American states. One explanation for low participation rates, has been the failure by some local authorities to bridge the gap between people's attitudes and behaviour. Research has shown that a gap exists between people's environmental attitudes and action. Previous experiments have employed antecedent and consequence conditions to influence the factors that limit environmental action, in an attempt to close the gap between attitudes and behaviour. This paper reports on the research carried out by Cardiff University and De Montfort University, which has attempted to identify and manipulate the factors that influence whether or not someone recycles in the Cities of Cardiff and Leicester. Different experiments were applied to different socio-demographic groups. Questionnaires were used to assess attitudes and behaviour before and after the implementation of a series of experiments. The research indicated that the interventions were more effective at increasing levels of recycling among existing recyclers rather than prompting non-recyclers to start recycling. The interventions differed in terms of their effect upon participation in particular sociodemographic groups. Key factors identified from the research could be equally applicable to other contexts of individual environmental action.     

Foreignness as a constraint on learning: The impact of migrants on disaster resilience in small islands

Knowledge about natural hazard management has increased significantly since Gilbert White's seminal research in 1945, yet people are still badly affected by natural hazards. A key question remains in natural hazards research: why, when all the conditions for effective disaster risk reduction are in place, do some people not take action to reduce their risk of harm? Through a questionnaire-based study we investigated the motivating factors that led residents of the Cayman Islands to prepare for annual tropical cyclones (hurricanes). Factors that increase the likelihood of individuals preparing for hurricanes are: previous experience of major storms, having linking networks and ties, having a child under the age of 15 in the home, and residency status—expatriate residents are less likely to prepare. Factors that appear to prevent adaptive behaviour include: living close to or adjacent to the coast, recent migration to the islands, and living in rented accommodation. The findings of the survey confirm that even within societies that are well prepared for tropical cyclones, there are still sub-groups who do not engage with the preparedness process. In the case of the Cayman Islands, new migrants are the most vulnerable to tropical cyclones as they tend to fall into the demographic groups least likely to prepare for cyclones, live in locations with high levels of exposure to cyclone impacts, and interact mostly with other expatriates with no previous experience of cyclone impacts. As climate change promises to bring an increasing intensity of tropical cyclones, these findings have relevance for all islands which draw on migrant workers to support economic growth.     

废线路板非金属物料再生利用新型工艺研究

以加热改性处理前后的废线路板非金属物料为对象,对其再生利用工艺进行了研究.通过添加硅烷偶联剂、润滑剂、抗氧化剂和改性剂等助剂改性共混,基于挤出注塑成型工艺过程,可制备废线路板非金属物料填充增强聚丙烯复合板材,该工艺同时可适合一定温度条件下加热改性处理后的非金属物料,其主要力学性能符合相关制品产品质量标准.确定的优化参数为:非金属物料添加质量分数30%,添加助剂包括硅烷偶联剂(1%)、润滑剂(1%)、抗氧化剂(1%)和改性剂(5%).