中国天然气分类及互换性标准探讨

随着我国天然气产业和市场的日趋管网化和互联互通,多种气源接入混输的跨区域大型管网成为发展的必然趋势。在上游多气源天然气供气的大前提下,下游不同用户对不同气质规格的天然气是否能够安全、环保的利用是我们必须面对和研究的重大问题。面对中国多气源和多用户的环境,以什么样的原则建立中国天然气的应用分类和互换性技术规范或准则,是本论文探讨的重点。通过借鉴国际上各国这方面研究经验,以及国际上在天然气分类及互换性标准问题方面研究的进展和成果,重点结合我国天然气气质的实际状况,基本掌握了我国天然气的气质现状,对我国天然气分类及互换性标准的建立原则和基本内容提出了建议。     

Conditions influencing the adoption of a soda tax for public health: Analysis of the French case (2005–2012)

Although over 40 jurisdictions have adopted a tax on sugar-sweetened beverages (SSBs) for public health worldwide, it is still debated in many places. Policy processes can influence the prospect of an SSB tax, its design and its public health benefits. To get an insight into such processes, we undertook a case study of the soda tax enacted in France on the 1^st of January 2012. Newspaper articles (2003–2013) and institutional documents (2007–2012) were identified using keywords and search engines. Qualitative data extraction and analyses were performed on a thematic and chronological basis, with guidance from Kingdon’s multiple streams theory (MST). Triangulation was enhanced by using complementary sources. This study shows that in August 2011, the French government surprisingly announced a €3.58 cent/L excise tax on SSBs, excluding juices with no added sugars and non-calorically sweetened beverages (NCSBs). As part of a large budgetary plan, the proposal aimed to reduce SSB consumption and raise revenue that was earmarked for health care. Several conditions contributed to opening a policy window: The announcement occurred in the context of severe budgetary deficits; soda tax scenarios had already been discussed at a high level; and the bill was supported by convinced political leaders. Subsequently, the tax successfully passed through the legislative process due to a series of unexpected events, but its public health rationale and design were weakened. The first event was the disorganised reaction by the food industry, despite their sharp opposition to the tax. The next event was the support of the soda tax that came from a majority of Deputies, provided that the revenues would serve another purpose: relieving wage costs in the farming sector. Finally, policy entrepreneurs favoured a compromise to make the tax politically acceptable and legally viable: The tax rate doubled, the scope was extended to NCSBs and revenues were split between health care and agriculture. This study sheds light on influence factors that could be taken into account by public health actors willing to influence soda tax policy processes.     

Investigating menu kilojoule labelling policy adoption from a political science perspective

Implementation of internationally recommended policy options for obesity prevention has generally been slow and inadequate globally, and, as such, it is important to understand barriers and enablers to policy action in the area. This study aimed to apply political science theories to understand influences on the adoption of Menu Kilojoule Labelling Legislation in Victoria, Australia over the period 2009–2017. Data collection included 13 in-depth semi-structured interviews with participants of the policy development and decision-making processes, analysis of 68 policy documents, and field note observations. Data were analysed using established political science theories: the Advocacy Coalition Framework (ACF) and the Multiple Streams Theory (MST). There were numerous and interrelating factors that influenced the Menu Kilojoule Labelling Legislative policy processes. Barriers to policy reform included electoral turnover, a dominance of neoliberal ideology, and policy maker concerns regarding potential food industry backlash. Key enablers to eventual policy change included the accumulation of evidence on policy effectiveness and feasibility of implementation, increased recognition of the importance of tackling the issue, as well as reductions in political risks achieved, in part, through relatively long consultation and negotiation processes. Findings highlight several tactics that can be used to secure similar policy change in future, including generation, dissemination and translation of implementation evidence, effective mobilisation of supporters, and negotiation and consultation processes that can reduce the degree of opposition to proposed policies.     

The long overhang of bad decisions in agro-industrial development: Sugar and tomato paste in Ghana

In theory, learning from past mistakes should result in adapted and improved development policy. However policy learning can be difficult to achieve, and the link between learning and policy change is neither direct nor immediate. In this study we look at learning in agro-industrial policy in Ghana, by tracing the interest in sugar production and tomato processing over six decades. Specifically we ask why four failed factories established in the early 1960s have continued to play central roles in both policy and public discourse. Using policy documents, academic material, and the popular press, we show that Ghana’s policy focus on sugar production and tomato processing has endured, despite the fact that the factories were misconceived, poorly sited, ill-equipped and poorly managed. Indeed, the political ideas that underpinned the establishment of these factories in the early days of independence can be seen in the current One District, One Factory policy. We suggest that it is their symbolic and political value, not their economic value, which keeps the discussion around these factories alive. Even when shut down, they are a physical manifestation of historic commitments by the state, and as such they guarantee the attention of politicians, and hold out hope of a next re-launch. Unfortunately as long as the factories continue to be incorporated into each new generation of agro-industrial policy, it is difficult for any alternatives to gain traction. This analysis highlights the very long overhang of bad decisions, particularly when they are associated with physical infrastructure. Learning from past mistakes will only happen if the short-term political cost of turning policy learning into policy action can be overcome.     

基于天然气放空系统的水力计算软件开发

高压天然气放空系统由放空干线管段气体、放空管线及外界大气组成。放空管路属于非稳定流动,其水力计算不能采用一般站场管路的达西公式。以Fano方程为基础,运用流体力学及输气管路流动基础理论进行程序编写,计算软件可实现对各时刻放空所对应的瞬时放空量、累计放空时间、截面压力及温度、储气量的求解。计算结果与图解法进行对比,误差控制在2%以内,弥补了图解法仅可求得瞬时放空量而无法得到其他参数的缺陷,并利用东河伴生气管线下沉工程现场放空数据与本计算软件对比,计算结果吻合度高,符合现场工程实际。     

超声流量计自诊断技术在天然气计量中的应用

随着超声流量计在天然气计量领域的广泛应用,其自诊断技术也不断得到改进,为流量计现场计量的准确、可靠提供了保障。详细阐述了超声流量计的主要技术指标,以及波形图、增益值、信号质量、信噪比、流速特性等主要自诊断方法,还对声速核查法进行了介绍。有效利用超声流量计的自诊断与维护技术,不仅能确保流量计处于良好的运行状态、准确计量,也可核查计量系统中压力、温度和组分变化。     

基于过程挖掘的物流运作风险发现研究

为了探究物流运作过程中存在的风险,提高物流运作效率,增强物流企业管理能力,以真实的事件日志为基础,运用过程挖掘方法发现物流企业运作过程中的风险。首先以Petri网理论为基础,构建了理想的工作模型,然后使用过程挖掘工具ProM,运用模糊挖掘算法和启发式挖掘算法,对物流运作过程中产生的真实事件日志进行挖掘,获得实际的客观视图,最后利用ProM工具的一致性检查发现物流运作过程中的异常行为模式,并分析物流运作过程中的偏差以及存在的风险。结果表明,过程挖掘能客观地揭示事件日志中活动之间的依赖关系,并发现物流企业自身运作过程中的偏差和风险。研究结果为全面、系统地分析物流企业潜在风险提供了新思路,有助于物流企业发现运作过程中的问题,对物流企业优化运作过程和提高管理效率具有重要的借鉴意义。     

化工工艺设计安装的重要性

随着中国科技领域不断发展,化工行业在科技进步的带动下取得前所未有的发展成果。对于化工企业而言,化工工艺设计与安装属于自身发展的关键所在,需要受到高度重视。文章针对上述内容展开研究,分析化工工艺安装具有的重要作用,总结相关工作经验。     

油气管道环焊缝新型修复技术研究

为了寻求适应高钢级油气管道环焊缝缺陷的新型修复方法,克服传统修复技术的局限性,提出了电弧增材制造技术用于油气管道环焊缝修复的可行性。首先,对激光熔覆、冷喷涂、电弧增材制造3种新型修复技术进行对比分析后,采用电弧增材制造技术进行实验研究;其次,在X80管道环焊缝处沿轴线截取22 mm厚的试样,并在环焊缝处设计坡口角度为60°,坡口深度为11 mm的缺陷,采用电弧增材制造冷金属过渡工艺、ER50-6焊丝进行修复实验;最后,对修复试样进行力学实验测试,并对实验数据和断口形貌进行分析。实验结果表明,电弧增材制造修复后试件抗拉强度最高达639 MPa,强度与管体基材匹配。研究结果表明,电弧增材制造技术用于X80油气管道环焊缝缺陷的修复是可行的,具有沉积效率高、成本低、力学性能能满足修复要求的特点,对于高钢油气管道环焊缝缺陷修复的可行性和经济性具有重要的现实意义。