交通运输投入占用产出模型研究

交通运输业是国民经济的基础支撑产业,他对国民经济的其他产业存在着广泛、多层次的直接和间接影响.目前,交通运输发展面临着巨大的环境压力和资源约束,编制交通运输投入占用产出表并对其应用进行研究有助于国民经济快速、平稳、协调发展.文中设计了交通运输投入占用产出表,并对该表如何进行编制做了说明.在模型构造原理的基础上,对模型的主要特征做了解析说明,如模型的行向分析和列向分析,并对模型的实用性及部分用法做了说明.     

我国客车工业发展的有利条件及现状和建议

介绍了我国客车工业发展的有利条件和发展现状,并对车身焊接、涂装质量控制提出了建议。     

全球价值链下的中国汽车产业升级研究

利用全球价值链理论介绍了全球汽车产业的发展,接着对合资模式和自主创新模式在中国汽车产业升级中的利弊进行了分析,并从全球价值链的角度对中国汽车产业的升级提出了建议。     

地铁盾构长距离下穿对既有铁路框架桥影响的数值与实测分析

地铁盾构近接施工产生的地层扰动与变形会对既有敏感构筑物使用安全造成威胁。为分析盾构下穿施工对既有铁路建构筑物变形的影响,以长沙地铁6号线盾构长距离下穿京广铁路客货运框架桥为工程背景,建立盾构下穿施工的三维数值模型。研究不同注浆压力、土仓压力及地层加固情况下框架桥和轨道的变形受力特性,并结合现场实测数据分析盾构掘进参数的变化特征及既有结构的变形规律。模拟结果表明：盾构左线先行施工对框架桥和轨道变形的影响大于右线;注浆压力和土仓压力的提高,以及地层加固措施的采取,能有效控制框架桥和轨道的沉降变形;轨道结构变形随注浆压力和土仓压力的提高而减小,分别达到0.30 MPa和0.16 MPa后继续提升时对沉降控制效果逐渐减弱。实测数据表明：右线盾构掘进参数相比左线较小且更稳定,总推力和刀盘扭矩控制在13 000 kN和3 500 kN·m以下可确保安全快速掘进;框架桥和轨道变形随盾构掘进变化明显,下穿前变形较小,下穿时变形开始增大,下穿后变形逐渐稳定;框架桥整体变形在-1.75～1.37 mm之间,轨道变形在-3～2 mm之间,轨道高低偏差和变形速率均小于控制标准。在施工过程中应重点关注先行隧道的...     

基于零件库的应用服务平台研究

主要以汽车行业为背景,提出了基于零件库的应用服务平台的内容和目的,以及其分布式系统架构及分布式自组织管理模式。介绍了开发的基于零件库的应用服务平台的2个案例:CAD图形数据转换的应用服务和产品配置的应用服务。     

政府干预卫生行业的原因、措施及效果比较——以英、美、德、新为例

卫生行业有很大的特殊性,国外政府大都对卫生行业进行不同程度的干预,运用了不同的干预措施并产生了不同的效果。本文首先总结分析了国外政府干预卫生行业的六个主要原因,接着从医疗服务融资方面、医疗服务提供方面和监管方面比较分析了英国、美国、德国和新加坡政府的具体干预措施及其效果,以期对我国政府更好地干预卫生行业提供有益的决策参考依据。     

Modeling the impacts of alternative emission trading schemes on international shipping

Various market-based measures have been proposed to reduce CO₂ emissions from international shipping. One promising mechanism under consideration is the Emission Trading Scheme (ETS). This study analyzes and benchmarks the economic implications of two alternative ETS mechanisms, namely, an open ETS compared to a Maritime only ETS (METS). The analytical solutions and model calibration results allow us to quantify the impacts of alternative ETS schemes on the container shipping sector and the dry bulk shipping sector. It is found that an ETS, whether open or maritime only, will decrease shipping speed, carrier outputs and fuel consumption for both the container and dry bulk sectors, even in the presence of a “wind-fall” profit to shipping companies. Under an open ETS, the dry bulk sector will suffer from a higher proportional reduction in output than the container sector, and will thus sell more emission permits or purchase fewer permits. Under an METS, container carriers will buy emission permits from the dry bulk side. In addition, under an METS the degree of competition within one sector will have spill-over effects on the other sector. Specifically, when the sector that sells (buys) permits is more collusive (competitive), the equilibrium permit price will rise. This study provides a framework for identifying the moderating effects of market structure and competition between firms on emission reduction schemes, and emphasizes the importance of understanding the differential impacts of ETS schemes on individual sectors within an industry when considering alternative policies.     

China’s electric car frustrations

By 2020, the vehicle population in China will likely exceed 280 million—exacerbating national energy security, urban air pollution, and traffic congestion. In response, many local and regional governments in China are pursuing an expanding array of measures to restrain growth in personal vehicle ownership and, along with the central government, reducing emissions and energy use of vehicles. One prominent strategy is the promotion of new energy vehicles, especially plug-in electric vehicles (PEVs). Large subsidies were offered—up to $27,600 (171,000 RMB) per vehicle in some regions, including almost $9200 (57,000 RMB) from the central government—which suggests that China is making a major commitment to PEVs. But sales have been meager. In 2013, only 17,600 PEVs, mostly buses and utility trucks, were sold, less than 0.1% of total civilian vehicle sales. Several factors explain the failure of PEV sales to take off: (1) protectionism by local governments; (2) uncertainty over which electric-drive vehicle technologies to promote and what consumers are willing to pay, (3) lagging investments in charging infrastructure, and (4) conservative investment behavior by automakers and battery manufacturers. The central government issued directives to local governments in late 2013 to reduce barriers to out-of-town companies, resulting in modest sales increases in early 2014, but a more coherent, broader, and effective set of policies, incentives, and strategies are needed to overcome consumer and industry resistance and the lack of charging infrastructure.     

电子诊断在现代汽车维修新技术中的实践探析

交通部数据显示,2019年全国机动车保有量达到3.4亿辆,机动车数量的增长,进一步激发了汽车制造行业的发展.由于机动车运行环境比较复杂,在运行过程中,受到路况、汽车工艺性能等方面的影响,汽车可能出现故障.随着我国汽车制造业的发展,传统的汽车维修技术已经无法满足现代汽车工业的发展需求,推动了电子诊断技术在现代汽车维修技术...     

大断面越江电力管廊隧道管片接头力学行为研究

为了探究盾构隧道管片接头力学性能,基于苏通GIL综合管廊隧道工程,采用有限元软件ANSYS建立用三维精细化数值模型对其接头力学参数和破坏过程进行计算和分析,并采用试验方法对接头力学行为进行分析,将试验结果与数值计算结果进行对比分析。结果表明:接头竖向位移、接头转角和接头抗弯刚度与接头内力关系曲线具有明显的分段线性或非线性特征,其中接头竖向位移和接头抗弯刚度与弯矩的关系曲线可以分为两段,接头转角与弯矩的关系曲线可以分为3段;轴力对管片接头的各项力学参数均有不同程度的影响;正弯矩接头的破坏始于外弧面混凝土压溃;试验得到的接头力学参数和数值计算结果均呈现出相同的变化规律,验证了数值计算的可信度。