复合超声振动游离磨料抛光技术及其实验研究

本文针对超光滑表面的需求,提出了一种游离磨料振动强化抛光加工方法,该抛光方法以游离磨料作为介质,在抛光过程中加以超声空化作用的辅助,加上工件的高速振动,使流体分子或微细磨拳斗粒子能不断冲击工件表面,从而获得超光滑表面。进行了相关实验,并得出了一系列结论。     

油水井套变地层岩石力学参数反演分析

以套管变形测井资料为基础,利用APDL编制有限元优化模块反演套变围岩力学参数,即可确定套变地层缺失的力学参数,又克服目前套管变形分析多是基于弹性模型,不能进行塑性变形分析的问题。同时在岩石力学参数反演程序中引入莫尔―库伦破坏准则,确定岩层内摩擦角与黏聚力、最大水平主应力和最小水平主应力之间的关系,使反演解具有唯一性。该方法为套变围岩岩石力学参数的确定提供了新方法,并较传统反演方法更为简捷高效。     

中国利率期限结构的非线性动态调整:基于MS-VECM模型的研究途径

基于MS-VECM模型对预期理论调整作用下的中国利率期限结构非线性动态过程进行的实证研究,结果表明:预期理论在中国利率期限结构中是成立的;中国利率期限结构具有两区制的非线性动态特征,可以按预期理论的调整强度将两种区制分别描述为"强调整区制"与"弱调整区制";不同期限利率的平均变动幅度和平均风险溢价水平会随区制状态变化而发生变化,具有区制相依性,区制间的转移具有非对称性;利率期限结构与物价压力的非线性区制划分具有相似性,物价波动是利率期限结构非线性动态变化的重要原因。     

非线性定价的福利再分配效应研究——基于非对称双寡头市场的分析

较之"线性定价","非线性定价"在社会福利方面的优势被现有理论反复证明。在肯定"非线性定价"方式能够改进社会总福利的同时,指出并不是每一个市场主体的福利水平都能够通过"非线性定价"方式得到改进。通过建立模型、计算和比较分析,提出了在上述两种情况下,"非线性定价"可能会对特定的市场主体产生"福利剥夺",从而出现福利再分配效应。     

销售电价政策性调整模型及其分析

销售电价改革呼声日涨,销售电价由市场决定是改革的最终目标,考虑到我国实际情况及电力行业作为国民经济的基础,实现销售电价由政府管制状态向市场化的平稳过渡是改革成功的关键。本文从电价制定者的角度出发,考虑基础产业价格的敏感性与社会福利最大化,设计出基于非线性规划理论和最优控制理论的销售电价静、动态调整模型,使用Kuhn—Tucker定理和Hamilton方法求解模型并给出仿真算例。结果表明：本文设计的静、动态调整模型均能实现电价有效平稳过渡,而基于最优控制的动态调整策略更能有效利用电力资源和充分增加社会整体福利。     

中国省际经济增长的空间关联网络结构--基于非线性Granger因果检验方法的再考察

文章基于经济增长空间传导的非线性趋势,利用最新发展起来的非线性Granger因果检验技术,对中国省际经济增长的空间溢出关系进行了识别,并在社会网络分析框架下揭示了其网络结构特征。研究发现：（1）线性 Granger因果检验方法严重低估了中国省际经济增长的空间关联性,而采用非线性Granger因果检验方法不仅可以揭示出更多的空间关联关系,而且能够识别出更多可能的空间溢出渠道,这为提升中国经济增长的空间协同效应提供了更多的实证支持。（2）中国省际经济增长从整体上呈现出更紧密的、更稳定的网络结构形态,在中国省际经济增长的最大可能性网络（ML-Network）中没有任何一个省份能够“孤立”于整体网络。“不谋全局者,不能谋一域”,必须从全局的、整体的视角重新审视中国区域经济的协调发展,探寻并创造出更多的空间溢出渠道,发挥经济增长不同板块的不同功能,实现区域经济空间的协同发展。     

铝硅镀层22 MnB5高强钢高温拉伸性能及本构模型

为了分析和表征热成形用的铝硅镀层22MnB5高强钢的热变形行为,采用Gleeble-3800热模拟试验机,在成形温度750～900℃、应变速率0.1～10 s~(-1)试验条件下实施了铝硅镀层22MnB5高强钢的板材等温拉伸试验,采用双曲正弦型Arrhenius本构模型描述铝硅镀层22MnB5高强钢的高温流变行为,并考虑应变影响构建了模型。结果表明:1)铝硅镀层22MnB5高强钢的真应力随成形温度的升高而降低,随应变速率的增大而升高,在高温低应变速率条件下(900℃,0.1 s~(-1)),峰值应力为134.24 MPa;在低温高应变速率条件下(750℃,10 s~(-1)),峰值应力为381.25 MPa; 2)本构模型预测值与等温拉伸试验值线性拟合的相关系数R~2为0.978,表明构建的本构模型在整个应变范围具有良好的预测精度。研究成果能够准确表征铝硅镀层22MnB5高强钢的热变形行为,为其数值模拟提供材料模型数据支持,并为其热加工工艺研究提供了参考。     

Nonlinearities in the real exchange rates: new evidence from developed and developing countries

This paper investigates nonlinearities in the dynamics of real exchange rates. We use Monte Carlo simulations to establish the size properties of the Teräsvirta-Anderson test, when the dynamics of the real exchange rate is influenced by an exogenous process. In addition, we show that a modified nonlinearity test, which includes additional right-hand-side variables, performs much better than the original in both Monte Carlo exercises and in the actual data on 1431 bilateral real exchange rate series. Finally, we investigate the dynamics of the real exchange rate for both developed and developing countries using the modified test for the recent floating period. In general, the results find a greater incidence of nonlinear dynamics for developing country real exchange rates.     

Are they telling the truth? Revealing hidden traits of satisfaction with a public bike-sharing service

Public bike-sharing systems (BSSs) are an emerging mode of transportation introduced by municipalities to solve congestion problems in metropolitan areas, especially when integrated with other types of transportation. In the last years, the number of public bike-sharing services has been constantly on the rise all over the world, and generally the overall satisfaction with them is high. However, satisfaction with public services is driven by mechanisms that can differ from those in the private sector. It is important to establish to what extent a high satisfaction is genuine or simply ephemeral. Even “old” public services (like public transportation) become “gold” when accompanied by the introduction of new technologies. In this paper we analyze this phenomenon using data from a satisfaction web-survey conducted among customers of the public BSS “BikeMi” in Milan, Italy, in a period when mobile technologies have been introduced to speed up the service. On analyzing the responses to satisfaction questions using simple summary statistics, the level of satisfaction resulted very high. However, our aim was to look for potential “darker” sides of the service by detecting possible hidden satisfaction components. For this purpose, we used the Nonlinear Principal Components Analysis, which is particularly powerful in this context. A simple textual analysis was also performed as a validating test. Results from our analysis indicated that satisfaction is flawed by a set of factors like the mechanics of the bikes, the picking and dropping system, and the apps used to organize the service. Less concern was detected for more general aspects of the service.     

Asymmetric effects of exchange rate movements on traditional and modern services exports: Evidence from a large emerging economy

The service sector in India has emerged as the ‘new engine of growth’ with an increasing share in output and exports. In this paper we analyse the effect of real exchange rate movements on service exports of India, incorporating goods exports, financial development, FDI inflows, world demand and the role of globalization as drivers. We find that while traditional service exports are negatively and significantly affected by the real exchange rate movements, the modern service exports are negatively but not significantly affected. By applying the asymmetric cointegration approach, the results also confirm the non-existence of any asymmetric relationship between the real exchange rate and service exports in India. Further, the results also show that the supply augmenting and demand-side factors are more dominant than the exchange rate to affect service exports from India.