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《International Journal of Hydrogen Energy》2022,47(66):28585-28604
Hydrogen transportation by pipelines gradually becomes a critical engineering route in the worldwide adaptation of hydrogen as a form of clean energy. However, due to the hydrogen embrittlement effect, the compatibility of linepipe steels and associated welds with hydrogen is a major concern when designing hydrogen-carrying pipelines. When hydrogen enters the steels, their ductility, fracture resistance, and fatigue properties can be adversely altered. This paper reviews the status of several demonstration projects for natural gas-hydrogen blending and pure hydrogen transportation, the pipeline materials used and their operating parameters. This paper also compares the current standards of materials specifications for hydrogen pipeline systems from different parts of the world. The hydrogen compatibility and tolerance of varying grades of linepipe steels and the relevant testing methods for assessing the compatibility are then discussed, and the conservatism or the inadequacies of the test conditions of the current standards are pointed out for future improvement. 相似文献
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工程总承包是国际通行的建设项目组织实施模式,在水利建设领域起步较晚,目前的水利工程总承包机制尚不健全,影响了其优势的发挥。对水利工程总承包模式下工程参建各方组织界面问题进行科学有效的管理优化,构建以信任为基础的合同关系,制定适合工程总承包集约化管理规范,树立精益建造为主的工程总承包理念,进而提高水利工程总承包管理成效,促进水利工程建设管理水平提升。 相似文献
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为解决当前我国PPP模式面临的以经济效益为主要目的,忽视社会与环境影响的问题,针对PPP项目进行系统、全面的可持续性评价迫在眉睫。基于“三重底线”理论,结合PPP项目特征从经济、社会、环境、合作及项目特征5个维度建立了可持续评价指标体系,包括14个可持续标准指标和45个关键属性指标。引入模糊逻辑思维构建评价模型,通过三重模糊数学计算得出PPP项目整体可持续性指数,采用欧几里得距离法确定PPP项目可持续水平,并识别出阻碍项目可持续水平的因素,并以说明性案例分析验证模型的可行性和合理性。 相似文献
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Responsible innovation in infrastructure projects can promote the sustainable development of infrastructure projects where the strategies of the stakeholders involved have a significant impact on this process. This paper constructs a tripartite evolutionary game model including the government, focal enterprises, and the public to simulate and analyze their behavioral strategies and the sensitivity to relevant influencing factors at different phases of infrastructure projects. The results demonstrate that the government acts as a leader in the initial phase, and gradually evolves into the role of guardian in the intermediate and operational phases. Lower supervision costs, heavier penalties, and public participation can promote responsible innovation by focal enterprises and responsible supervision by the government, while higher incentive subsidies will generate the focal enterprises' behavior of “defrauding subsidy.” A three-dimensional framework for responsible innovation in infrastructure projects is developed based on the research results, covering the project life cycle, stakeholders, and responsibility and benefits, which embody the coupling mechanism of infrastructure projects’ responsible innovation. 相似文献
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Public-private partnership (PPP) projects have been widely applied in infrastructure construction. A suitable risk distribution strategy is crucial for promoting negotiations between the government and investors. The government usually provides guarantees to investors to distribute risk. However, an excessive guarantee increases the government's financial burden, whereas an insufficient guarantee reduces the confidence of the investors participating in the project. In a minimum revenue guarantee (MRG), the government subsidizes the investors the difference between the actual revenue and the government guarantee line if there is a loss. In PPP power plant and highway projects, investors' revenues come from two sources: government guarantees and the project company's self-sale. To support project companies and to optimize the projects' benefits, the government should set a reasonable benchmark for purchase amounts. Based on the traditional principal-agent model, this paper introduces the reciprocal preference theory to analyze the risk-sharing ratio most suitable for the government. Then, an optimal incentive mechanism is established to guarantee the project's income. The results indicate that by setting a different guarantee strategy for different participants, the government can utilize reciprocal preference to incentivize investors to exert more effort during a partnership and avoid moral hazard. 相似文献
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随着我国房地产整体产业的迅速发展,越来越多的资金投入房地产市场,与此同时各种不确定因素所造成的投资风险也越来越受到人们的重视,因此,在房地产投资行为中建立一个完整的房地产项目投资风险评价体系显得尤为重要。在房地产项目投资风险的相关理论基础上,通过 AHP 和物元理论的评价方法,建立相关风险评价体系,结合尧沙房地产项目的实际情况收集相关数据,对投资风险进行分析,分析结果表明该评价方法具有可行性。 相似文献
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兰州水源地工程输水隧洞全长31.29km,沿线地质条件复杂。为准确获得该超长输水隧洞沿线的初始地应力场分布情况,分别采用多元线性回归方法(方法1)和粒子群-神经网络智能反演方法(方法2)开展了初始地应力场研究。结果表明,兰州水源地工程输水隧洞沿线地应力属中等地应力场,以水平构造应力为主,埋深较大时(380m)逐渐转变为以自重应力场为主;两种方法所得地应力值均与实测值相近,方法2的计算精度较方法1高,但计算量约大4倍,因而大范围地应力估算时方法1具有计算量小、精度足够的优点,而局部范围地应力估算时方法2精度更高、效果更好。 相似文献
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