首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到12条相似文献,搜索用时 31 毫秒
1.
基于不可压缩黏性流体理论VOF(VolumeofFluid)方法建立了二维数值波浪水槽模型,将模拟波形与波浪理论值进行对比,分析了模型可靠性,并利用该模型研究了5种不同前墙结构OWC气室在不同波高、周期时的出气口速度和气室内空气压强。基于模拟结果,从波能-动能转换效率和气室内空气压强角度分析了前墙结构对OWC气室的捕能效果的影响。结果表明:对于传统的直立型OWC 气室,采用合适的前墙结构可有效提高OWC气室的捕能效果;相比三角截面(20D型,30D型)和矩形(Y型)截面前墙,采用椭圆截面(20TY 型,30TY 型)的前墙结构的捕能效果更优,且在周期较大(1.6和1.8s)时其作用更显著,其波能-动能转换率相对Y 型前墙结构气室平均提升37%;5种前墙结构不同的气室中,20TY型和30TY型前墙结构气室的捕能效果最优。  相似文献   

2.
3.
    
The circular economy (CE) can bring benefits but also pitfalls to the production processes, affecting a firm's economic performance. Using data from European SMEs, we empirically investigate, from the perspective of self-determination theory, the extent to which the breadth of CE activities, that is, the number of CE activities undertaken by a firm, affects a firm's economic performance. Our study theorizes and shows that there is an inverted U-shaped effect brought about by the number of CE activities on economic performance. This research advances our scientific understanding of the CE and provides managers with suggestions on how to maximize the benefits generated by the CE in terms of economic performance by implementing the right amount of CE activities.  相似文献   

4.
The increasing awareness of environmental issues attracts more attention on environmentally friendly energy sources. This leads to increasing research on effective use of renewable energy sources. Among them, wave energy offers a high potential. The wave energy converter systems used for transforming the wave energy into electrical energy have been a main research topic for decades. However, only a few of these systems has been successfully implemented. There seems to be some technical problems one of which is on their control applications. It has been reported that by means of appropriate control implementation, the performance of the wave energy converter system could be improved considerably. In literature, many different control techniques are reported. They appear to be weak due to implementation related restrictions. The present study proposes a novel control technique that is far more practical based on quantization of control settings. Various quantization levels and their effect on system power capture performance are studied. The technique assumes use of realistic off-the-shelf components with realistic features. The proposed method utilizes time-series-analysis technique with online parameter estimation feature. This new method does not require any knowledge of previous or future states of any of the system or sea state parameters, but only the currently available and measurable ones. The approach of the new control technique sets it apart from most of the previously reported ones. Therefore, the proposed technique is not only very much practical but also very much useful in improvement of the system power performance relative to passive techniques.  相似文献   

5.
对国内第一个岛屿地形下核电厂的护岸防洪设计进行了研究,提出直立式护岸结构方案以满足核电厂防洪和避让毗邻海岛的要求。在波浪数值模拟计算结果基础上,开展了波浪整体物理模型试验、波浪局部整体物理模型试验和波浪断面物理模型试验,对护岸的越浪量和结构稳定性进行了优化验证。研究结果表明,岛屿地形下,波浪破碎和波能集中导致护岸堤身坡脚处波高增大,须加高挡浪墙和优化挡浪墙结构型式;在相同的越浪量标准下,采用直立堤结构相对斜坡堤结构对应的护岸挡浪墙的高程须明显加高;利用部分海岛地形斜坡高地作为厂区护岸一部分时,原状海岛地形斜坡高地处的波浪爬高效应明显,须加高邻近护岸挡浪墙的高程。  相似文献   

6.
反应堆重混凝土拆除解体技术概述   总被引:1,自引:0,他引:1  
反应堆生物屏蔽层重混凝土的拆除解体是反应堆退役过程中的难点之一。本文对重混凝土拆除解体技术进行了详细的调研。结果表明:金刚石串珠绳锯、空心镗削法和金刚石圆盘锯可以对反应堆重混凝土进行拆除解体。  相似文献   

7.
    
Airlines' negative impacts are rising due to the growth of the industry, and therefore new and more sustainable alternative business models are being developed and implemented. In this context, this paper analyses how airlines are incorporating Circular Economy (CE) into their service model and proposes a framework to identify the main practices of CE that support waste management. After a detailed review of the corporate social responsibility (CSR) reports of a worldwide sample of companies, this paper builds on waste and material management, where airline activities have more impacts on edible and inedible waste. Results show that companies are adopting measures such as recycling in-cabin waste, incorporating new materials, and defining new systems to make the feeding services more efficient. Nevertheless, CE adoption is still low, and the CE strategies do not seem to follow specific patterns.  相似文献   

8.
介绍了山东省蓬莱市发展低碳经济和循环经济的具体情况,总结了蓬莱市发展"两种经济模式",引领全市经济健康持续发展的几点启示。  相似文献   

9.
我国合同能源管理制度创新机制研究   总被引:1,自引:0,他引:1  
节能减排是建设\"环境友好型、资源节约型\"社会进程中的核心问题之一。相对于\"控制、命令\"型的政府主导的节能模式,运用市场化机制促进节能的合同能源管理模式具有其独特的资源配置优势。我国合同能源管理近年来虽有较大的发展,但在信用体系建设、融资平台建设、能效评估体制和政府采购制度等诸多方面存在改进空间。  相似文献   

10.
This article critically examines the nature and quality of governance in community representation and civil society engagement in the context of trans-national large-scale mining, drawing on experiences in the Anosy Region of south-east Madagascar. An exploration of functional relationships between government, mining business and civil society stakeholders reveals an equivocal legitimacy of certain civil society representatives, created by state manipulation, which contributes to community disempowerment. The appointment of local government officials, rather than election, creates a hierarchy of upward dependencies and a culture where the majority of officials express similar views and political alliances. As a consequence, community resistance is suppressed.  相似文献   

11.
    
In nature, fish have gained wonderful swimming ability over the thousands of years of evolution. As the fish swims, its body, namely, it’s dorsal or tail fin undulates and then alternating waves are sent down the body towards the tip of the tail. These waves generate a jet in the wake and hence a forward force, namely thrust. Scientific studies have already shown that undulatory swimming is a highly effective means of continuous locomotion and has been successfully adopted in many kinds of robotic fishes currently being developed. However, our latest research found that if wave velocity that defines the undulatory motion of the body or the ‘fin’ is less than a specific value, the fishlike body with undulatory motion also has the capability to harvest kinetic energy from flowing fluid. This finding proposes a new energy-harvesting concept which could offer a new and promising solution to support the long-distance voyage of a biomimetic robotic fish.  相似文献   

12.
    
Energy is an essential asset for the existence of industrial activities, however, the absence of energy use management may lead to numerous environmental, economic, and social impacts. Thus, industries, which are major consumers of energy, play an essential role in seeking to preserve the energy system. This study aimed at analyzing the practices of energy use management and their relation to sustainable performance in the industries within the Brazilian mineral sector. The practices of energy use management were measured using the model proposed by Liu et al. (2012, Journal of Cleaner Production, 26, 79–89). After that, evidence of sustainable performance was identified based on performance indicators developed by the Global Reporting Initiative (2006, 2010, 2014). The study is characterized as quantitative, and it was conducted through a survey of industries linked to the Brazilian Mining Association. Through our results, we verified that the practices related to energy use management existent in the companies that we studied are subjected to periodic verification of the impacts caused by company activities on the environment, and that attention to energy use provides an incentive to daily practices of energy saving. On the other hand, the practices of energy use management are still little disseminated among these companies, as is certification to the International Organisation for Standardization's (ISO) Energy Management Systems framework, ISO 50001. In general, through the analyses that we performed, we can verify the existence of positive associations between the factors related to the practices of energy use management and to corporate sustainable performance.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号