我国煤炭输送方式经济性方面的研究工作

煤炭运输方式的经济性问题是制定能源产业政策的基本理论问题之一,为此回顾了我国五十年代以来的部分有关研究工作,对不同时期的部分研究实例从研究方法、技术方案和研究结论三个方面进行了对比分析,揭示了不同研究工作在基本原理方面的一致性和技术方案方面的差异性,以及由此造成的研究结论的异同。     

石油储量价值评价中运销成本级差模型的设计与检验

对石油资源价值评价中的4个成本因素之一——运销成本级差因素进行了讨论。文中分析了运销成本级差因素的组成因子之后．建立对之进行测算的数学模型，并就两个油田的实测数据给出了计算结果。     

Accelerators as start-up infrastructure for entrepreneurial clusters

ABSTRACT

Infrastructure is commonly conceptualized as a set of facilities that play a critical role in facilitating activities by individuals and organizations. Conventionally, infrastructure is tightly linked to publicly funded projects that facilitate access to key resources and enable diverse activities. Within entrepreneurial clusters research, infrastructure includes universities, research institutions and telecommunication technologies that facilitate entrepreneurial activities. These capital-intensive investments seek to facilitate start-ups emergence by aiding access to markets and development of ideas. Accelerators facilitate the same activities and have only recently been conceptualized as start-up infrastructure. This study builds upon this research stream by elaborating on how accelerators can play this meaningful role at the cluster level. Specifically, and by relying on the analysis of empirical evidence from three distinct studies, we uncover how accelerators provide tangible and intangible dimensions of start-up infrastructure to form a positively reinforcing cycle of entrepreneurial activities. Additionally, our findings allow us to push further the idea that start-up infrastructure development can be an endogenous process involving multiple actors within the cluster. Our empirical findings and the theoretical insights derived from them have meaningful implications for the aforementioned literature, as well as start-up practitioners and policymakers linked to the funding of entrepreneurial clusters.     

Analysing job creation effects of scaling up infrastructure spending in South Africa

In a first for South Africa, this article draws on literature on infrastructure productivity to model dynamic economy-wide employment impacts of infrastructure investment funded with different fiscal tools. Using a dynamic computable general equilibrium model, the South African investment plan is modelled, given the infrastructure externality. Alternative fiscal scenarios to finance the policy are modelled in the article. In the long run, unemployment decreases for all types of workers under one of the scenarios. In the short run, only elementary occupation workers benefit from a decrease in unemployment; for the rest, unemployment rises.     

Economic contribution of essential air service flights on small and remote communities

The Essential Air Service Program (EAS) has attracted considerable criticism and has been a target for either modification or complete termination almost since its inception through the Airline Deregulation Act in 1978. Although its opponents emphasize the program's inefficiency, its supporters claim that the program is crucial to accessing small and remote communities, which helps them develop economically and socially. This paper demonstrates the economic contributions of EAS flights to small and remote communities. Using a two-stage least squares estimation, the major findings indicate that a 1% increase in air passenger traffic in EAS airports with a minimum annual air passenger traffic of 1000 likely leads to a 0.12% increase in per capita income of the community served by that airport. Our results also suggest that EAS communities that are able to sustain their subsidized flights experienced higher per capita income growth in the 1999–2011 period than did ex-EAS communities that lost their flights as a result of non-eligibility.     

Pre-positioning of relief items in humanitarian logistics considering lateral transhipment opportunities

The main objective of this study is to investigate the inclusion of lateral transhipment opportunities into the humanitarian relief chain and to examine the effect of different parameters on minimizing the average distance travelled per item while serving the beneficiaries. Direct shipment model (DT), lateral transhipment model (LTSP) and maritime lateral transhipment model (MLTSP) are developed and compared between each other by using a real life earthquake scenario prepared for the city of Istanbul by JICA (Japanese International Cooperation Agency). Developed mathematical models decide on the locations and number of disaster relief facilities, quantity of relief items to hold at those facilities, and quantity of lateral transhipment between the facilities. Vulnerability of the roads and heterogeneous capacitated facilities are also considered. It can be concluded that both LTSP and MLTSP models gave better results than DT model and lateral transhipment option helps beneficiaries to obtain relief items faster and with higher service level.     

浅谈对电厂基建和技改工程竣工图管理的想法

工程档案,建设工程档案是由工程文件经鉴定、整理、归档后形成的。项目工程档案主要包括工程前期文件、工程施工文件、工程竣工验收文件、竣工图及设备厂家资料图纸等。     

目前我国城镇基础设施投融资模式分析

在我国经济建设步伐加快,各级地方财政普遍吃紧的情况下,直接财政投资、土地储备制度等传统融资模式已不能满足城市基础设施融资的需求。继之出现的BOT、TOT、PFI、ABS和市政债券的投融资模式市场程度依次提高,共同的特点在于引入SPC作为桥梁将政府与市场在公共物品领域连接起来,这些融资模式合作形式各异,以公私合营和资本市场的力量为城建资金寻找到了更广泛的投资者。本文介绍了我国现行的城镇基础设施投融资模式,如土地储备制度和市政债券等,依市场化程度的高低对这些融资进行了分类分析和比较,指出未来我国城建融资模式的发展方向。     

ZY5000/15/32掩护式液压支架的优化设计

当支架工作一定时间后出井维护时,需要将前梁与顶梁之间的销轴拿掉后改为运输销轴连接,由于井底空间、设备有限,操作极为不便;另外,由于前梁千斤顶是靠销轴受力,因为支架工作时间比较长且井下环境恶劣,导致销轴出现变形、生锈等现象,以致销轴不易拆卸。     

加强基础设施建设,提升中心城区的辐射带动能力

在新型城镇化进程中,加强中心城区的基础设施建设、提升中心城区的承载能力、发挥中心城区的辐射带动作用十分重要。本文在分析了黄河三角洲地区中心城市基础设施建设存在不足的基础上,提出了加强中心城区基础设施建设的看法与建议,旨在为全面提升该区域的城镇化水平提供参考。