无缝线路施工技术

无缝线路的推广应用是20世纪铁道工程领域最优秀的成绩之～，我国正线无缝线路已达到4万多公里。无缝线路比普通线路接缝少，是将许多根标准长度钢轨焊接成相当长的轨条并铺布在轨枕上的线路。它有助于减少列车能耗，保持列车运行平稳，冲击振动少，旅客舒适；车辆冲击轨缝的噪声减轻，有利于环境保护，是铁路现代化的主要内容之一，是轨道结构的发展方向。本文阐述了无缝线路铺设施工技术的几个要点。     

浅议轨道工程无缝线路施工技术

无缝线路是用焊接长轨条铺设的轨道,因为长轨条没有轨缝而得名。无缝线路分温度应力式及放散温度应力式两种。目前世界各国绝大多数均采用温度应力式无缝线路。本文就无缝线路的工程实践,介绍了长钢轨基地焊接、单元轨节的工地焊接;无缝线路锁定和钢轨伸缩调节器的铺设等技术,并对长钢轨焊接和无缝线路铺设中应注意的问题进行了探讨。     

一次铺设无缝线路长钢轨施工技术

轨道是铁路固定设备的重要组成部分,其高平顺性是保证开通时达到设计速度的关键。我国以往既有铁路无缝线路铺设是在路基、道床稳定的条件下,将工厂焊接的长钢轨（250m～500m）运至工地焊联成1km～2km的单元轨节,再在既有轨的基础上利用换轨小车换铺到轨道上,经过应力放散、焊联锁定成为无缝线路。     

钢筋混凝土轨枕硫磺螺栓锚固技术研究

钢筋混凝土轨枕硫磺螺栓锚固是用硫磺水泥砂浆将螺栓与混凝土枕联结的一种工艺流程,具有强度高、使用可靠、成本低、施工方便和易于维修的特点。但是,必须保证硫磺锚固的良好质量才能得到满意的使用效果和使用寿命,现结合工程实际,就如何保证高寒地区轨枕硫磺螺栓锚固质量进行了研究和总结,以期对同类项目有所借鉴。     

超限超重T梁、长轨铁路运输技术研究

本文介绍了超长及大吨位铁路T梁、长轨采用铁路运输时,对运输车辆选择,T梁加固方式,运行线路的策划。     

长钢轨运输列车偏载问题探究

摘要：长钢轨运输列车在高速运行中各种惯性力会引起钢轨在车辆中移动，从而造成车辆偏载，可能导致行车设备损坏或车辆脱线、颠覆等严重事故。文章通过一段时间内长钢轨运输列车发生偏载问题的数据统计对比，根据车辆结构特点，分析原因和安全风险源点，给出安全防控措施。     

地下管廊非标准轨距铁路轨道铺设施工关键技术分析

铺轨施工测量和轨道精调测量作业是提升轨道平整度和平顺性的重要工作。本文以苏州至南通GIL综合管廊工程为工程研究对象,详细阐述了地下管廊中非标准轨距轨道铺设施工工艺,提出了分两次浇筑道床混凝土的措施,确保了直埋式整体道床施工后可以为后续钢轨焊接提供作业空间的要求,详细阐述了焊轨过程中的质量控制要点,为今后类似工程提供参考和借鉴。     

怎样利用轨检车成果指导线路维修工作

本文阐述了轨检车检测线路时包括了哪些检测内容、评价方式以及怎样利用轨检车的检测成果来指导线路维修工作.     

无缝线路铺设

无缝线路是用标准长度的钢轨焊接而成的长钢轨线路,又称为焊接长钢轨线路。无缝线路被公认为是20世纪轨道结构最突出的改进与创新。     

缓坡长斜洞施工中溜槽技术的应用

文章介绍了开口式溜槽技术在距离长、坡度相对较缓的斜洞施工中的应用,混凝土运输由传统的泵送╲斗车运输改为溜槽运输。该项技术的成功应用,打破了常规有轨斜洞混凝土运输方式,较好地解决了长距离斜洞内钢衬安装施工和混凝土浇筑交叉施工产生的相互干扰问题,大大地提高长斜洞混凝土的运输能力,保证钢管安装、回填混凝土的浇筑质量,加快施工进度,有较好的推广使用意义和参考价值。     

Software for Learning and for Doing Statistics

The community of statisticians and statistics educators should take responsibility for the evaluation and improvement of software quality from the perspective of education. The paper will develop a perspective, an ideal system of requirements to critically evaluate existing software and to produce future software more adequate both for learning and doing statistics in introductory courses. Different kinds of tools and microworlds are needed. After discussing general requirements for such programs, a prototypical ideal software system will be presented in detail. It will be illustrated how such a system could be used to construct learning environments and to support elementary data analysis with exploratory working style.     

A model for predicting determinants factors for NEETs rates: Support for the decision-makers

The purpose of this paper is to analyze the determining factors of the high levels of NEETs both in EU member states and in partner countries, to support policy steering and increase socio-economic cohesion. The use of longitudinal data (2005–2020) from Eurostat and World Bank databases and selected and the testing of a number of 19 factors likely to influence the rate of NEETs show us that the effectiveness of public policy solutions focused on this category of population increases when complex factors and not singular elements are targeted. From a methodological point of view, we will use MARS models and fixed effects panel models. To account for countries’ heterogeneity, these models are applied to homogeneous groups of countries, identified through cluster analysis. Social cohesion and sustainability measures for policy steering have higher chances if the action of the responsible institutions targets both meso and macro levels, if it acts not only on a factor but also on the causes that favor its manifestation. Our analysis demonstrated that the measures aimed at increasing the chances of NEETs in order to facilitate their access to education, the labor market, and social inclusion must be coordinated with those of support for combating poverty and any type of exclusion, the support given to employers (subsidizing jobs, for example), the family and the community to which the young person belongs or local authorities. Also, the research results show us that there are more common elements between countries when we analyze the factors likely to increase the rate of NEETs than when we focus on their analysis by geographical criteria, based on EU membership status or EU partner status, etc.     

“集约”创造新的空间

去年以来，党中央和国务院从民族的长远利益出发，从经济可持续发展和构建和谐社会出发，十分明确地提出了坚守18亿亩耕地的红线不能突破的目标要求，并作了一系列重大部署。     

Techniques for defining geographic boundaries for health regions

Many federal and state programs require the geographic partitioning of states into regions for health services planning, monitoring, and/or administration. A common consideration for such programs is that region boundaries should be drawn so as to maximize the proportion of the state's population that receives health care services in its region of residence. Defining region boundaries thus may be viewed as a problem of partitioning a set of N small areal units (e.g. counties) into M subsets (regions) so as to minimize interactions (patient flow) among subsets. This paper describes three algorithms for region design and compares them in terms of computer-processing efficiency and solution value based on results from a number of test cases. Application of two of the algorithms, one based on the greedy heuristic and the other incorporating a max-flow/min-cut procedure, to a problem of dividing a metropolitan region into separate service areas for clusters of hospitals is also described.     

人才战没有国界

2003年12月19日至20日,中共中央、国务院在北京召开全国人才工作会议.中共中央总书记、国家主席胡锦涛在会上发表重要讲话. 他强调,实施人才强国战略,是抓住和用好重要战略机遇期、应对日益激烈的国际竞争的必然要求,是全面建设小康社会、开创中国特色社会主义事业新局面的必然要求,是增强党的执政能力、巩固党的执政地位的必然要求.     

Going for Gold: Atlanta's Bid for Fame

This article explores the importance of image to the Atlanta Olympic Games of 1996. It suggests that the event must be seen as an example of the use of the propagation of selected images designed to boost the standing of the city in an increasingly competitive interurban environment. The intersection of major sporting spectacles, big business and vastly increased television coverage provides an important new medium through which boosterists can put their city on the world map. However, as the Atlanta case reveals, the ‘semiotics of the successful city‘ involves a highly ideological construction which often presents urban areas as conflict‐free zones. In Atlanta, potentially negative images were removed both physically and symbolically from the urban landscape, while the actual experience of the Games suggested that the city had some way to go in material terms to match its often hyperbolic self‐promotion. The article suggests that the staging of events such as the Olympics is a necessarily high‐risk venture for cities, one that, as in the case of Atlanta, may not have been ultimately worth the effort. Cet article examine l'importance de l'image dans le cadre des Jeux Olympiques d'Atlanta de 1996. Il propose de considérer l'événement comme un exemple de la diffusion d'images sélectionnées, conçues et utilisées afin de promouvoir la réputation de la ville dans un contexte interurbain de plus en plus concurrentiel. L'intersection entre des spectacles sportifs exceptionnels, de grandes entreprises et une couverture télévisuelle considérablement étendue constitue un moyen novateur grâce auquel les promoteurs de cette dynamique peuvent positionner leur ville sur la carte du monde. Cependant, comme le montre le cas d'Atlanta, la ‘sémiotique d'une ville gagnante’ implique une construction idéologique très forte qui présente souvent les zones urbaines comme des espaces non conflictuels. À Atlanta, les images à potentiel négatif ont étééliminées à la fois physiquement et symboliquement du paysage urbain, tandis que les Jeux eux‐mêmes laissaient à penser que la ville devait progresser sur le plan matériel si elle voulait correspondre à son auto‐promotion souvent hyperbolique. L'article suggère que la mise en scène d'événements tels que les Jeux Olympiques est une opération nécessairement très risquée pour des villes, opération qui, à l'instar de l'expérience d'Atlanta, peut finalement ne pas justifier les efforts réalisés.     

基于决策有用性的财务报告方式选择

决策有用性是会计信息披露的目标,而决策有用的前提是会计信息应具有可靠性和相关性。可靠性和相关性犹如鱼和熊掌一样,往往不可兼得。以信息观或计量观为基础的财务报告方式在满足可靠性和相关性的程度上存在着差异。文章从财务报告的信息观和计量观的角度,分析了财务报告方式选择的条件,并提出了提高会计信息有用性的几点建议。     

Distribution-free Approximate Methods for Constructing Confidence Intervals for Quantiles

Quantile estimation is important for a wide range of applications. While point estimates based on one or two order statistics are common, constructing confidence intervals around them, however, is a more difficult problem. This paper has two goals. First, it surveys the numerous distribution-free methods for constructing approximate confidence intervals for quantiles. These techniques can be divided roughly into four categories: using a pivotal quantity, resampling, interpolation, and empirical likelihood methods. Second, a method based on the pivotal quantity that has received limited attention in the past is extended. Comprehensive simulation studies are used to compare performance across methods. The proposed method is simple and performs similarly to linear interpolation methods and a smoothed empirical likelihood method. While the proposed method has slightly wider interval widths, it can be calculated for more extreme quantiles even when there are few observations.     

Change point test for tail index for dependent data

To test for the constancy of tail index, Quintos et al. (Rev Econ Stud 68:633–663, 2001) proposed three types of change point tests for independent and ARCH type sequences. In this paper, we demonstrate that their tests can be successfully extended to a large class of dependent stationary sequences. Further, we designate a time-reverse version of those tests since the original tests produce very low powers in case the tail of distribution gets thinner. A simulation study is implemented for illustration.