一种基于有限元计算的半挂车强度分析

用有限元计算方法对某型半挂车车架的强度进行了分析计算。通过有限元仿真计算,提出在进行局部加强的同时,采用细而密的横梁结构的优化方案,解决了原来结构的应力集中现象,确保半挂车的结构强度。     

Smallholder Farmers and Collective Action: What Determines the Intensity of Participation?

Collective action through farmer groups can be an important strategy for smallholders to remain competitive in rapidly changing markets. Previous research has analysed determinants of farmer participation in groups, equating participation with group membership. However, within groups the commitment of members can vary, as marginal benefits and costs are not the same for all individuals, and opportunities to free‐ride exist. Low participation in collective activities may reduce the ability of groups to provide useful services to its members. This article investigates determinants of member participation intensity, using the example of farmer groups in Kenya. The role of individual and group characteristics is analysed with survey data and regression models. Previous benefits that members received through the group positively influence their intensity of participation in group meetings and collective marketing, suggesting that reciprocity motives play a role. Low participation can mostly be attributed to structural and institutional conditions, such as group size and the timing of payments for collective product sales. More diversified farmers are less likely to sell collectively when group marketing activities only concentrate on one particular commodity. Since smallholders are often highly diversified, the focus of farmer groups should also be broadened. Further policy implications are discussed.     

The Impact of Involvement,Perceived Moral Intensity,and Satisfaction upon Trust in Non-Profit Relational Contexts: Processes and Outcomes

ABSTRACT

This study applies the basic concepts of relationship marketing, including involvement, knowledge, moral intensity, satisfaction and trust in the non-profit environment, specifically in a university setting. These relational concepts are employed in the development of a relational model used in an exploratory investigation. Results indicate significant relationships between the constructs, emphasizing the importance of relationship management for non-profit and public sector entities. Results, managerial implications and research implications are included.     

基于物质流分析的区域循环经济发展动态研究——以山东省为例

运用物质流分析(MFA)方法,对山东省生态经济系统1996-2010期间的物质输入与输出进行系统分析,揭示了山东省经济发展与环境压力的关系.研究结果印证了区域资源综合利用效率和废弃物输出效率的提高,反映出近年来山东省大力发展循环经济,调结构、转方式效果的显著性.     

Energy benchmarking in support of low carbon hotels: Developments,challenges, and approaches in China

Achieving effective and objective energy benchmarking for hotels is integral in fostering the sustainable development of the lodging sector. In this work, we reveal the major and minor streams of hotel energy benchmarking and ascertain that the most popular approach in benchmarking is normalized energy use intensity (EUI) based on floor level. Previous efforts to establish EUI indicators using subsystem average, data envelopment analysis (DEA), and regression technique are also studied. We propose that hotel energy benchmarking based on floor area is useful from the top-down management perspective. However, on a practical perspective, energy benchmarking based on facilities should be the first priority for hotel management or owners. Compared with the general energy benchmarking in the building sector, we find that the hotel sector lags behind in the adoption of computer modeling for benchmarking.     

价格因素对我国地区能源强度的影响

本文从能源价格和劳动力价格两个方面进一步分析价格要素对于能源强度的作用机理,分析了我国能源价格体系存在的问题,并针对存在的问题提出了相关政策建议,为更有效地控制能源强度提供一定的帮助,弥补了现有能源强度影响因素理论研究的不足。     

股票回购、现金股利替代性与研发投资——基于迎合渠道的比较分析

传统观点认为,股票回购与现金股利存在替代关系,同时在资金约束以及管理层短视情形下,二者对企业中长期研发投资支出产生负向冲击。而“边分红,边研发”却是目前我国上市公司的普遍现象。基于此背景,利用2014-2017年我国A股上市公司样本数据,在迎合渠道下分析股票回购与现金分红行为对研发投资的影响及差异。研究发现：两种分配行为并非具有完全替代性,虽然二者均会通过迎合渠道对研发投资产生正向影响,但迎合渠道又存在差异。其中,现金股利多通过股权融资渠道发挥作用,而股票回购多通过理性迎合渠道发挥作用。     

最优能源强度与我国经济增长

本文通过一个内生增长模型对能源消费与经济增长的关系进行了分析,证实存在使经济增长率最大化的最优能源强度,并且最优能源强度与能源价格反方向变动.在此基础上,估计了近年来我国的最优能源强度,并测算了实际能源强度与最优值的差距.结果表明,近年来我国实际能源强度高于最优值达3万吨标准煤/亿元以上,且有不断上升的趋势.最后提出了在保持最优能源强度的前提下降低能源消耗的政策建议.     

R&D Efforts,Total Factor Productivity,and the Energy Intensity in China

ABSTRACT

This paper first measures the levels and growths of regional TFP in China using a panel dataset of China’s 30 provinces from 1978–2014. It then estimates the effects of R&D on regional TFP and its growth further explores the impact of TFP on China’s energy intensity. We find no evidence that R&D has innovation and spillover effects on TFP and its growth in China’s provinces. Nevertheless, R&D can promote growth in regional TFP by helping to absorb new technologies embodied in FDI and foreign trade. The results indicate that TFP plays a significant role in the decline of China’s energy intensity.