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81.
乌金峡水电站灯泡贯流式机组投运初期,因设计、制造、安装等诸多原因导致机组故障率较高,经过2 a多来的消缺、技改,机组运行可靠性、稳定性逐步提高,逐步取得了一定的效果。文章针对具体问题产生原因及相关改进措施予以阐述,并进行相关优化分析探讨。 相似文献
82.
对大型抽水蓄能电站首机首次2种启动试验方式的特征水力参数和经济性评估方法等问题进行分析研究,并结合某电站工程实际,选定特征水力参数和基本试验项目,作了水力计算和经济性评估. 相似文献
83.
根据梯级水电站群远程集控调度的特点,研究了适用于梯级水电站群的优化调度算法。讨论了梯级水电站群优化调度准则,对几种典型优化算法的适应性和局限性进行了分析比较。结果表明,在流域梯级电站数量较少时可采用动态规划算法,在流域梯级电站规模较大时可采用基于遗传算法的改进型优化算法。按照流域梯级水电站的实际情况采用适应的优化算法,才能发挥梯级水电站远程集控优化调度系统的优势。 相似文献
84.
EFTHYMIOS G. PAVLIDIS IVAN PAYA DAVID A. PEEL 《Journal of Money, Credit and Banking》2018,50(5):833-856
The wide fluctuations of oil prices from 2003 to 2008 have attracted the interest of academics and policymakers. A popular view is that these fluctuations were caused by speculative bubbles due to the increased financialization of oil futures markets. This hypothesis, however, is difficult to examine since the fundamental price of oil is unobservable and, therefore, econometric evidence in favor of bubbles may actually be due to misspecified market fundamentals. In this paper, we extend two recently proposed methodologies for bubble detection that alleviate this problem by using market expectations of future prices. Both methodologies provide no evidence of speculative bubbles. 相似文献
85.
86.
芮孝芳 《水利水电科技进展》2017,37(2):1-6
凭借"大数据"可以精细刻画降雨空间分布和下垫面空间变异性的优势,提出了"大数据"背景下考虑降雨空间分布和下垫面空间变异性对流域产汇流影响的计算方法,即单元嵌套网格剖分流域的方法。通过引入"网格水滴"的概念揭示了流域瞬时单位线的物理本质,对由RodriguezIturbe和Valdes所提出R-V地貌瞬时单位线理论进行补充,分析了等流时线法和单位线法的局限性,提出的单元嵌套网格产汇理论既克服了等流时线法和单位线法的缺点,也吸取了它们的优点,为在"大数据"支撑下统一等流时线和单位线法提供了可行性。 相似文献
87.
随着国家经济的快速发展,各行各业都在不断地进步和创新以适应时代的脚步,建筑作为国之富强的一项外在体现,应该更加的加强建筑的质量,完善建筑监理体系,建设利国利民的高质量建筑,下面就关于建筑监理体系建设作出一些简单的讨论。 相似文献
88.
This article employs methodologies based on fractional integration and cointegration to analyse the time-series properties of merger and acquisitions (M&A) activity and crude oil prices in the US from 1980 to 2012. Our results indicate that an increase in the crude oil price produces a significant increase in the M&A data between 2 and 3 months after the initial shock. 相似文献
89.
This paper demonstrates that the framing of post-war Kowloon Walled City through photos has been dominated by the maps commonly used to represent this Chinese enclave in colonial Hong Kong as a place. Inspired by and extending Wylie’s (2009) argument that emptiness and presence are equally important, this paper uses basic GIS techniques and hitherto unpublished archival materials to help (a) argues that the colonial government’s mindset of clearly defining the spatial boundary of the city, which is a subtle admission of an officially and diplomatically denied otherness in ownership, created the city as a quasi-cadastral unit; and (b) explains how this shaped the framing of the landscape of the city by promoting investment and trade in high-rise housing development units. The government did not destroy its walls. When these were physically destroyed, it did not ignore the walls’ original alignments but treated the city as a planning unit, as if they still existed. 相似文献
90.
By using both macro‐ and micro‐level data, this paper investigates how wages and prices evolved during Japan's lost two decades. We find that downward nominal wage rigidity was present in Japan until the late 1990s, but disappeared after 1998 as annual wages became downwardly flexible. Moreover, nominal wage flexibility may have contributed to Japan's relatively low unemployment rates. Although macro‐level movements in nominal wages and prices seemed to be synchronized, such synchronicity is not observed at the industry level. Therefore, wage deflation does not seem to be a primary factor of Japan's prolonged deflation. 相似文献