An Oligopolistic Investment Model of the Finnish Electricity Market

The investment problem faced by producers in deregulated electricity markets contains high uncertainties about the future. It can also be seen as a game, as only a small number of large players act in the market. A dynamic stochastic oligopoly model to describe the production and investment in such a situation is developed and applied to the Finnish electricity market. The demand growth rate is modeled as a stochastic variable. The strategies of the firms consist of investments and production levels for base and peak load periods. The firms have nuclear, hydro and thermal capacities, but are only allowed to invest in new thermal capacity. Using a so-called sample-path adapted open-loop information structure, the model contributes to the understanding of the dynamics of production, investment and market power in a medium time horizon. The solution method uses recent developments in variational inequality and mixed complementarity problem formulations.     

水电施工企业创新行为市场演化博弈分析

针对水电施工企业如何选择创新战略,政府如何引导企业进行创新,运用演化博弈理论分析了创新行为与市场结构的演化规律.研究表明,市场中企业采取自主创新或模仿创新的行为战略最终演化稳定均衡,即市场中总有一定比例的企业进行自主创新,其余的企业采取模仿创新,并且企业自主创新投资的概率与企业的规模成正比,与创新风险成正比,与创新成本成反比.由此我们得出,若企业个体规模小、自主创新成本高、创新所获收益小,则可采取模仿创新战略,反之,采取自主创新战略;对于政府若想维护市场稳定,提高行业技术水平和国际竞争力,对自主创新成本高、创新所获收益小的可采取补贴、减税等优惠政策,以鼓励企业采取自主创新.     

中国城镇居民生活用能影响因素定量研究

利用面板数据对中国城镇居民生活用能影响因素进行了实证分析.结果表明,能源消费总量对人均可支配收入的弹性最大,人口对城镇居民用能具有广义的规模效应,居民用能对能源价格很敏感.此外,夏季与冬季的温差每上升一摄氏度,城镇居民生活用能总量会上升3%.如果一个地区有集体供暖,其城镇居民部门能源消费总量会比没有集体供暖时减少19%.     

Pricing in Electricity Markets: A Mean Reverting Jump Diffusion Model with Seasonality

This paper presents a mean‐reverting jump diffusion model for the electricity spot price and derives the corresponding forward price in closed‐form. Based on historical spot data and forward data from England and Wales the model is calibrated and months, quarters, and seasons–ahead forward surfaces are presented.     

Improving the performances of direct-current triboelectric nanogenerators with surface chemistry

Over the past decade, triboelectric nanogenerators (TENGs) – small and portable devices designed to harvest electricity from mechanical vibrations and friction – have matured from a niche theme of electrical engineering research into multidisciplinary research encompassing materials science, physics, and chemistry. Recent advances in both the fundamental understanding and performances of TENGs have been made possible by surface chemistry, electrochemistry, and theoretical chemistry research entering this active and promising field. This short review focuses on the recent developments of direct-current (DC) TENGs, where sliding friction or repetitive contact–separation cycles between the surface of polymers, metals, chemically modified semiconductors, and more recently even by the simple contact of surfaces with water solutions, can output DC suitable to power electronic devices without the need of additional rectification. We critically analyze the role of surface chemistry toward maximizing DC TENG outputs and device longevity. The major current hypotheses about their working mechanism(s) are also discussed.     

太阳能热电耦合合成苯甲酸

通过恒电位电解甲苯实现了苯甲酸的太阳能热电耦合合成, 考察了电极材料、 反应温度及电解电压对苯甲酸合成的影响. 采用气相色谱、 红外光谱和紫外光谱对电解产物进行分析检测, 证实了太阳能热电氧化甲苯的主要产物为苯甲酸. 实验结果表明, 以石墨作为阳极材料, 反应温度为90 ℃, 电解电压为2.0 V时, 氧化甲苯合成苯甲酸的产率可达51.6%.     

大规模风电并网的双供应源电力供应链牛鞭效应分析

中国当前的电力供应链除具有部分垄断特征外,还由于大规模风电并网使得电力供给也出现随机性,它与随机需求一起影响了供应链信息的准确传递,在电力供应链产生了牛鞭效应,但对这类问题的研究极少。本文在分析中国电力供应链特点的基础上,构建了由煤炭供应企业、发电厂(火力发电和风力发电)和用户组成的多级电力供应链模型,揭示了牛鞭效应在单/双供应源两种供应链类型下的变化。研究结果表明,大规模风电并网形成的双供应源电力供应链牛鞭效应较大且波动剧烈,尤其当下游用户需求较平稳时,供应链会出现牛鞭效应与反牛鞭效应共存现象,而预测技术的选择、风电场合理规划等有助于抑制牛鞭效应,保证电力安全并减小资源浪费。     

Active compliant wall for skin friction reduction

In order to reduce skin friction drag, an active laminarisation method is developed. Laminar-turbulent boundary layer transition caused by Tollmien–Schlichting (TS) waves is delayed by attenuation of these convective instabilities. An actively driven compliant wall is integrated as part of a wing’s surface. Different configurations of piezo-based actuators are combined with an array of sensitive surface flow sensors. Wall-normal actuation as well as inclined wall displacement are investigated. Together with a realtime-control strategy, transition onset is shifted downstream by six average TS-wave lengths. Using the example of flow velocity, the influence of variable flow conditions on TS-damping rates was investigated. Besides, the boundary layer flow downstream of the active wall area as well as required wall deflections and the global damping effect on skin friction are presented in this paper.     

利用VB模拟升降法测电子电荷实验

密立根首创的油滴实验精确地测量出基本电荷量,是一个名而有启发性的近代物理经典实验。本主要介绍利用Visual Basic模拟并对实验数据进行处理的辅助教学课件。     

指数回归-ARMA模型在我国人均生活电力消费量预测中的应用

随着我国经济快速增长、居民收入水平的显著提高,生活电力消费量快速增长。本文以1983-2006年我国人均生活电力消费量的历史数据为基础,根据趋势图拟合出与之相似的指数回归曲线,然后对其残差序列进行分析和识别,找出适合我国人均生活电力消费量的指数回归-ARMA模型,并根据此模型进行预测分析。