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排序方式: 共有1962条查询结果,搜索用时 11 毫秒
81.
龚攀  刘金兰  张婷婷 《价值工程》2011,30(35):131-132
文章以因素分析法为基础,对影响石油企业收入的总销量,流向比例,汽柴比,牌号比例,到位价格率和到位价格等因素进行深入的分析探讨,这对于石油企业指导日后的生产经营情况,具有一定的参考价值。  相似文献   
82.
中国石油企业环境保护战略规划研究   总被引:1,自引:0,他引:1  
针对石油企业环境问题的现状,采用SWOT分析法,分析了石油企业实行环境保护战略的所面临外部的机会与威胁及内部的优势与劣势,从石油企业环境保护战略的基本原则、各阶段目标及战略重点方面进行了规划,研究结果有利于国家石油资源的战略安全、油田所在地的经济振兴和城市的稳定发展及石油企业的可持续发展。  相似文献   
83.
张久新 《价值工程》2011,30(17):50-50
采油设备的安全运行,直接关系到油田的生产效率和安全,通过采油设备的科学化状态检测,对油田采油工作的运行具有重要的意义,文章在分析采油设备状态监测理论意义的基础上,对采油设备状态监测管理的内容进行探讨,在此基础上提出了加强采油设备日常监测的措施,为提高油田的安全生产,设备的使用效率和使用寿命,作出理论研究和参考。  相似文献   
84.
Good News and Bad News: Search from Unknown Wage Offer Distributions   总被引:1,自引:0,他引:1  
The largest market in national economies is the labor market. Labor market contracting is characterized by job search, often from unknown wage offer distributions. This paper reports experimental tests of finite horizon models of job search in which the wage offer distribution is unknown. Theoretically-optimal search from an unknown wage offer distribution can have the seemingly paradoxical property that some offers will be accepted that are lower than other offers that will be rejected in the same period of the search horizon. Thus the reservation wage property (or lowest acceptable wage path) may not exist. This can occur because an offer that is a priori relatively high (good news) can imply that it is highly probable that search is from a favorable distribution, and such an offer can look unattractive when it is an a posteriori relatively low offer from a favorable distribution (bad news). This paper reports results from experimental treatments for search from unknown distributions in which the reservation wage property does exist and treatments in which it does not exist. We find that the consistency of search behavior with search theory reported in earlier papers is robust to the presence or absence of the reservation wage property and to whether the draws come from known or unknown distributions.  相似文献   
85.
2009年末,大唐碧口水力发电厂3号水轮发电机组在运行的一周内出现三次推力油槽油位下降的现象,给机组的正常运行构成了极大的威胁,同时也增加了大量的维护成本。经过对可能造成推力油槽油位下降多种原因进行分析论证,最终确认导致的推力油槽油位下降的原因为推力轴承油冷却器渗漏。在秋检时对3号机10台推力轴承油冷却器进行打压试验,发现4号油冷却器存在渗漏现象,将4号冷却器进行了整体更换后回装,机组运行至今再未发生推力油槽油位下降的现象。  相似文献   
86.
In recent years, the international crude oil price has become increasingly volatile. It influences the exchange rate changes of relevant countries through economic growth, price level, international balance of payments, and other channels. Such exchange rate fluctuations have caused certain risks for the development of China’s “Belt and Road” Initiative. This article analyzes the impact of oil price changes on the exchange rates of countries. Because the fluctuation of oil prices and exchange rates has shown the characteristics of multiple time scales, this study used the empirical mode decomposition (EMD) method to obtain the long-cycle and short-cycle sequences of oil prices and the exchange rates of various countries, then analyzed the impact of oil price changes on exchange rates under different time scales. The results showed that oil price fluctuations have an impact on the exchange rate changes of countries along the “Belt and Road” under different time scales. However, this effect is asymmetric between oil-producing countries and non-oil-producing countries, and the transmission path of oil prices to exchange rates varies from cycle to cycle.  相似文献   
87.
We examine the quantile serial dependence in crude oil prices based on the Linton and Whang’s quantile-based portmanteau test which we improved by means of quantile wild bootstrapping (QWB). Through Monte Carlo simulation, we find that the quantile wild bootstrap-based portmanteau test performs better than the bound testing procedure suggested by Linton and Whang. We apply the improved test to examine the efficiency of two crude oil markets – WTI and Brent. We also examine if the dependence is stable via rolling sample tests. Our results show that both WTI and Brent are serially dependent in all, except the median quantiles. These findings suggest that it may be misleading to examine the efficiency of crude oil markets in terms of mean (or median) returns only. These crude oil markets are relatively more serially dependent in non-median ranges.  相似文献   
88.
ABSTRACT

A panel smooth transition regression model was adopted to analyse the non-linear impact of oil prices on oil demand. Data for 42 countries was obtained from the International Energy Agency for the time period spanning from January 1990 to June 2017. The results indicate that a threshold value does exist. Furthermore, when the oil price was lower than this threshold value, a positive relationship between oil price and oil demand was observed. When the price of oil was higher than the threshold value, however, a negative relationship between price and demand was found.  相似文献   
89.
As an active trader in international crude oil and petroleum product markets, Australia's human welfare is affected by oil crisis and contagion from the perspectives of economic growth, income inequality, and environmental sustainability. This paper investigates the impacts of oil price shocks upon Australia's gross domestic product (GDP) growth, Gini coefficients, and carbon dioxide emissions per capita from 1970 to 2012 with yearly frequency. Hypotheses concerning whether Australia's economic immunity against oil crisis is affected after the deregulation of oil market and whether endogenous oil price shocks account for more variations in human welfare than exogenous oil price shocks are tested. The methodologies include a theoretic model and a series of econometric tests. For the short-run dynamics, oil price is integrated into the model both linearly and non-linearly. Oil price shocks are categorized into exogenous and endogenous shocks. The conclusions are that inflated oil prices exert mainly non-linear negative impacts upon human welfare indicators and exogenous shocks induce endogenous shocks through labor price, Consumer Price Index (CPI), interest rate, and exchange rate. For the long-run equilibrium, non-linear shocks' effects decay more slowly than linear shocks and the impacts of endogenous shocks last longer than that of exogenous shocks. Finally, oil market policies are evaluated and proposed.  相似文献   
90.
李凌  殷武  张信明 《物流科技》2009,32(5):82-85
首先,介绍了DEA评价模型的基本特点和评价步骤,建立了油料供应标准效果评价指标体系,而后利用DEA法对油料供应标准效果进行评价.并分析了DEA评价法的优缺点。  相似文献   
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