瞄准世界一流水平提升自主创新能力为实现铁路机车车辆装备现代化作贡献

中国南车集团四方机车车辆股份有限公司通过构建创新体系、加快工业化改造、大力提高人员素质,为引进消化吸收再创新奠定了坚实基础。为加快推进机车车辆装备现代化,采取系统实施技术转化、构建工艺设计体系、开展工艺平推、建立质量保证体系、严格进行试验调试等措施,以关键技术引进为核心,以系统集成技术和制造技术消化吸收为主线,全面开展引进消化吸收再创新工作,系统掌握了时速200km及以上动车组的核心技术,建立了一流的研发平台、制造平台和产学研联合开发平台,具备了高速动车组自主研发和国产化批量生产能力。     

Scale-Free Behavior in Weighted Stock Network

A weighted stock network model of stock market is presented based on the complex network theory. The model is a weighted random network, in which each vertex denotes a stock, and the weight assigned to each edge is the cross-correlation coefficient of returns. Analysis of A shares listed at Shanghai Stock Exchange finds that the influence-strength (IS) follows a power-law distribution with the exponent of 2.58. The empirical analysis results show that there are a few stocks whose price fluctuations can powerfully influence the price dynamics of other stocks in the same market. Further econometric analysis reveals that there are significant differences between the positive IS and the negative IS.     

对IEC 61373中模拟长寿命试验量级的分析

从疲劳损伤模型的选择上,对比分析IEC 61373《轨道交通机车车辆设备冲击和振动试验》2010版和1999版中模拟长寿命试验量级的差异性,对IEC 61373:1999中试验量级高于IEC 61373:2010的原因给出理论依据和解释。认为IEC 61373:2010更加符合机车车辆实际运行环境,试验检测时可避免过度试验对设备造成的损坏。据此提出对机车车辆设备模拟长寿命试验量级的选择建议和对标准的修订建议。     

股份制、合作制、与股份合作制

本文通过对股份制、合作制的分析，总结出股份合作制的制度特机     

Ludwig?s Ratchet and the Collapse of New England Groundfish Stocks

The stocks of principal groundfish species off New England have collapsed, creating economic hardship and dislocation in fishing communities from Rhode Island to Maine. In this article we analyze the causes of this collapse using the ?ratchet effect? described by Ludwig, Hilborn, and Walters (1993) as a framework. According to Ludwig, Hilborn, and Walters, powerful economic and political interests drive fisheries to overcapitalize and overexploit despite scientific evidence that stocks are declining. When the fishery is no longer economically viable, governments provide financial assistance to minimize economic hardship. When stocks increase there is another rush to invest, and the cycle repeats itself. The history of groundfish management in New England conforms well to this model. Optimism among fishers and government over U.S. control of this fishery in 1977 stimulated successive rounds of investment that built up excessive fishing capacity despite warnings from scientists that stocks were becoming weaker. Management regimes designed by the New England Fishery Management Council were ineffective in constraining fishing effort. Collapse of the stocks has led to severe restrictions on fishing and to government assistance. We suggest that the integration of science, management, and harvesting sectors through ecosystem-based management offers the best means of avoiding similar situations in the future.     

车辆结构建模中的几个难点及对策

针对车辆结构的具体特点及建模中的难点，总结了一些有普遍指导意义的建模对策。这些对策在一个典型敞车的有限元分析中取得了令人满意的结果，计算值与实验值十分接近。     

Developing a Sustainable Community-Based Aquaculture Plan for the Lagoon of CuyutlÀn through a Public Awareness and Involvement Process

This study presents evidence from the Cuyutlàn lagoon, which demonstrates that aquaculture can be socially acceptable, economically viable and environmentally friendly when consideration is first taken of the local circumstances and environment. This evidence was obtained through a user survey, which asked key questions of the local fishing community. These questions aimed to determine the desires and needs of the local community in the context of the local environment. The results from this survey of 56% of the fishing community were presented. The wishes of the fishing community are discussed and a compromise suggested for a sustainable aquaculture for the Cuyutlàn lagoon.     

解析铁道行业标准《机车车辆用材料阻燃技术要求》

介绍TB/T 3138—2018《机车车辆用材料阻燃技术要求》的修订背景、修订原则,重点分析取样要求、保温材料、通用橡胶材料、烟密度试验和45°角燃烧试验等主要修订内容。根据我国机车车辆防火标准体系规划,提出TB/T 3138—2018标准实施建议,以便标准使用者更好地理解和实施TB/T 3138—2018。     

对欧洲标准油压减振器测试规定的理解

根据对欧洲标准对测试机车车辆油压减振器的规定的理解,调查我国现有的减振器测试现状与检测各种试验台正弦激振精度后,找出差距,提出减振器测试中需试验台具备自测驱动精度、多点测试的发展目标。     

优化排样中顶点算法在圆弧轮廓上的完善

类多边形顶点算法是目前解决二维不规则图形排样的一种主流方法,应用较广泛。本文在基于顶点算法的理论基础之上,对于该方法在解决含有曲线轮廓的工件排样的不足的问题上,借鉴碰撞算法中碰撞点的提取理论,提出一种可行的完善方案。