轮胎温度场有限元分析系统的设计

文章针对轮胎在行驶过程中各部位胶料受热情况不一致这一特点,深入地研究了轮胎滚动过程中的稳态热平衡状态。并通过经验数据的积累,从轮胎结构的参数化设计、断面网格划分与有限元分析、温度场计算及结果输出5个角度,设计出轮胎温度场有限元分析系统,证明了输出的温度场云图与现实中稳态轮胎温度场的温度分布情况一致。     

European farmers and participatory rural appraisal: A systematic literature review on experiences to optimize rural development

Farmers are those who daily supervise and manage rural areas, but still their collaborations with those institutions entitled to decide the transformation of these territories are not managed properly. The experiences of participatory processes with the involvement of farmers are analyzed in many agricultural studies. A systematic review has allowed us to analyse experiences related to 35 participation paths aimed at rural regions’ development. The analysis has been made on the basis of 14 variables describing the path followed and its purpose, the agricultural holding involved and the areas surveyed.The work has the objectives to identify some strengths and weaknesses in the involvement of farmers in decision-making and the strengths and weaknesses of the processes themselves. The review has shown that too often in participatory processes farmers are considered only as a source of information to be used by researchers rather than as active participants in the choices for the protection, management and transformation of the rural territory. An effective participatory rural appraisal requires greater empowerment of farmers. In general, compared to the methods and tools used, farmers are wary of paths that are too complex and prefer the use of low-tech tools. This result can be attributed to the farmers’ demand of direct contact with the researchers to build trust and also to the average age of European farmers, which is pretty high.In participation contexts, it is not possible to establish standardized methods and tools, because each process should be tailored for the community that expresses it. Nevertheless, the work has highlighted the need to establish some minimum principles to avoid considering unsuccessful some participation paths which, in reality, have been only scarcely participated. In the work, these principles have been presented through the development of key questions, to which those who design the path for an effective engagement of agricultural stakeholder must respond: representativeness, empowerment, empirical knowledge, relationships, group type, numerosity and involvement stage.     

美国财政创新与重建对我国财政政策选择的启示

本分析了克林顿政府的财政创新与重建路径和实践结果，从中得出对我国财政政策选择的启示。     

Management of petroleum hydrocarbon contaminated sites in Nigeria: Current challenges and future direction

Sites affected by petroleum hydrocarbons from oil exploitation activities have been identified as a major environmental and socio-economic problem in the Niger Delta region of Nigeria. The current Nigerian regulatory instruments to manage these contaminated sites are fragmented and the roles and responsibilities of government agencies, such as the Department for Petroleum Resources (DPR), and the National Oil Spill Detection and Response Agency (NOSDRA), are not well defined. This lack of coordination has led to ineffective land contamination policy and poor enforcement more generally. Appropriate, risk-based policy instruments are needed to improve regulatory capacity, and to enhance the regulator's ability to manage new and existing petroleum hydrocarbons contaminated sites. Lessons can be learned from countries like the United Kingdom (UK) and the United States America (USA) that have experience with the management and clean up of historically contaminated land. In this paper, we review the status of petroleum hydrocarbon contaminated sites management in Nigeria and identify the gaps in existing policy and regulation. We review the contaminated land policies and regulation from the UK and the USA, and identify lessons that could be transferred to the Nigerian system. Finally, we provide a series of recommendations (e.g. source – pathway-receptor approach, soil screening criteria, clean-up funding, liability) that could enhance contaminated land legislation in Nigeria.     

China’s megaregion policy: Performance evaluation framework,empirical findings and implications for spatial polycentric governance

Megaregion has emerged as a new dimension of global urbanization. A megaregion approach based on polycentric strategy is deemed to enhance regional economic competitiveness. Numerous studies have highlighted the economic benefits, celebrated the spill-over effects, and outlined the creative potentials of contemporary megaregion policies in different nations worldwide. However, further policy instruments require the knowledge about the achievement and failure of megaregion policies that seek for spatial, economic, social, and environmental efficiency and sustainability. This paper introduces China’s megaregion policy and proposes an analytical framework for performance evaluation from four principle domains (rational urban growth, economic development, social equity, environmental protection) at three levels (internal collaboration, integral development, and overall development). Using a case of the Megaregion around Hangzhou Bay (MAHB), we find very limited success of China’s megaregion policy. In particular, the megaregion policy only accomplishes the economic goal, and fails to achieve the goals of rational urban growth, environmental protection, and social equity. A series of mechanism based regressions are established and show that the implementation duration of megaregion policy: (1) associates positively with the economic growth; (2) relates negatively to social equity and urban rational growth; and (3) has no significant relationship with improved environmental quality. Institutional fragmentation, no unified spatial planning, and inadequate legislation at megaregional level are the underlying causes of the expected performances within the policy context of governance itself. We finally propose some possible solutions and discuss the implications for spatial polycentric governance. The demonstrated methodological framework can be applicable to other megaregions around the world. This paper is thus believed to provide some new insights for land use policy.     

Assessment of regulation of legal relations of territorial planning: A case study in Lithuania

Land management is inevitably linked to the regulation of activities of its proprietor or operator stipulated by legislation and documents of territorial planning. In Lithuania, as in many European countries, territorial planning is a key measure for the formation of landscape and the alteration of its elements. With the help of territorial planning documents, governing authorities has the opportunity to orderly regulate the layout of long-term stable elements of landscape and the sustainable territorial development. However, in comparison with other European Union (hereinafter – EU) countries, territorial planning system valid in Lithuania until January 1, 2014 is still “young” and having specific features with former countries of the Soviet bloc legal regulation. The system did not provided a consistent and sustainable territorial development mechanism: there was the lack of measures allowing to manage the development processes of residential areas and implementation of territorial planning documents (especially the municipal master plans) solutions for the creation of a harmonious functional spatial system. The aim of the present paper is to assess the regulation of legal relations of territorial planning in Lithuania and the EU member states. The assessment summarizes processes of the formation of a landscape during the territorial planning, introduces new opportunities to more accurately predict the results of the current process of landscape planning, and highlights legal and sustainable elements of territorial planning system optimization. As can be seen from the assessment carried out, one of the most important territorial planning objectives was and still remains the balance of mutual relations (hierarchy of plans) of territorial planning documents in shaping the cultural landscape to ensure the rational distribution of the land fund, combining a variety of activities as well as often different land users’ and public interests. Therefore, the implementation of the territorial planning reform of Lithuania capacitates for the transition to an integrated territorial planning, ensuring sustainable development.     

Addressing the social landscape dimensions: The need for reconciling cross scale assessments for capturing Cultural Ecosystem Services (CES)

This special issue integrates eleven papers focussing on indicators able to convey the multiple expectations that society has concerning agricultural land. As scale issues have been so far overlooked within this research topic, a particular focus of this themed issue is to highlight the need for reconciling assessments across scales. The shared purpose of the contributions is to examine how the multiple societal expectations concerning agrarian landscapes might be incorporated into land use policy at different governance levels.A core set of these papers were presented in the symposium “Linking social indicators across scales”, to the European Congress of the International Association of Landscape Ecology (IALE) in September 2013 in Manchester, UK. This symposium was organized to create the time and space for a discussion on the issues of scale when capturing societal preferences concerning agrarian landscapes. While the landscape scale was specifically addressed by four papers, seven papers examined broader geographic units in addition to up-scaling and downscaling issues.     

Nondiscretionary residential water use: the impact of habits and water‐efficient technologies

Several studies published in the last few decades have demonstrated a low price‐elasticity for residential water use. In particular, it has been shown that there is a quantity of water demanded that remains constant regardless of prices and other economic factors. In this research, we characterise residential water demand based on a Stone‐Geary utility function. This specification is not only theory‐compatible but can also explicitly model a minimum level of consumption not dependent on prices or income. This is described as minimum threshold or nondiscretionary water use. Additionally, the Stone‐Geary framework is used to model the subsistence level of water consumption that is dependent on the temporal evolution of consumer habits and stock of physical capital. The main aim of this study is to analyse the impact of water‐saving habits and water‐efficient technologies on residential water demand, while additionally focusing attention on nondiscretionary uses. This is informed by an empirical application using data from a survey conducted among residents of Brisbane City Council, Australia. The results will be especially useful in the design of water tariffs and other water‐saving policies.     

Is forest carbon sequestration at the expense of bioenergy and forest products cost-efficient in EU climate policy to 2050?

Forest management affects the quantity of CO₂ emissions in the atmosphere through carbon sequestration in standing biomass, carbon storage in forest products and production of bioenergy. The main question studied in this paper is whether forest carbon sequestration is worth increasing at the expense of bioenergy and forest products to achieve the EU emissions reduction target for 2050 in a cost-efficient manner. A dynamic cost minimisation model is used to find the optimal combination of carbon abatement strategies to meet annual emissions targets between 2010 and 2050. The results indicate that forest carbon sequestration is a low-cost abatement method. With sequestration, the net present costs of meeting EU carbon targets can be reduced by 23%.     

Opportunity cost of water allocation to afforestation rather than conservation of natural vegetation in China

Estimation of ecosystem service values is a hot area of research in ecological conservation and economics. However, the costs of these outputs are largely unknown. In this paper, we estimated the opportunity cost of water allocated to afforestation projects through mathematical modeling based on statistical data for all of China to provide support for restoration planning based on a fuller consideration of the true costs. To guide future ecological conservation and environmental policy development, we illustrate a neglected concept (ecosystem service costs) and use this concept to compare the ecological services provided by ecological restoration based on afforestation with those of restoration based on the conservation of natural vegetation using data obtained since 1949 in China. The results showed that afforestation and natural vegetation create annual costs related to use of the available water resources equal to 4800 and 3700 RMB ha⁻¹, respectively, representing a water opportunity cost of 1100 RMB ha⁻¹ for afforestation. This illustrates the rule that “there is no free lunch” for any service, including ecosystem services. Therefore, to support the development of more effective and sustainable environmental restoration policy, it will be necessary to evaluate the associated opportunity costs.