可持续发展视野下的资源税

针对我国自然资源价格由于未包含环境成本,不利于资源的可持续开发利用进行分析,提出完善现行资源税使其符合可持续发展思想,为解决经济发展中自然资源稀缺的瓶颈问题提供参考。     

均质缸内直喷汽油机混合气形成过程的数值分析

针对某缸内直喷汽油机进行了喷油器喷嘴内部流场的多相流仿真分析,并将其结果作为初始条件输入到喷射模型中.将校定后喷射模型集成到缸内混合气动态分析模型,进而对发动机的缸内燃油与空气混合过程进行了欧拉--拉格朗日仿真分析.通过比较两款不同喷束的喷油器发现:缸内混合气的均匀度对于喷束布置较为敏感,比较宽广的喷束布置方案易于得到更加均匀的混合气.     

汽油机进气系统噪声仿真技术研究

基于非线性平面波理论和流阻分析技术,建立了汽油机进气系统噪声仿真平台,并进行了某汽油机匹配原进气系统管口噪声和流阻计算,计算结果与试验结果的对比表明该进气系统噪声仿真方法可行.针对某微型车更换动力总成后车内噪声没有达到目标样车水平的问题,提出了2种空气滤清器改进方案,并分别进行了2种方案的进气系统管口噪声仿真计算.结果表明,方案2最优,其不仅能降低某些转速的峰值噪声,还能保证车辆的动力性.     

基于层次分析法区间估计的我国燃油税定价影响因素筛选

在分析我国燃油税征收的目的和原则的基础上,提出层次分析区间估计方法并分析该方法较传统层次分析法的优越性.结合国外燃油税价格制定的成功经验,考虑我国燃油税征收条件,确定我国燃油税定价应考虑的影响因素.利用层次分析区间估计方法对燃油税定价影响因素的各因素进行分析和筛选,提出针对我国燃油税定价制定过程中应考虑的合理因素,为我国燃油税价格制定提出合理建议.     

The development of a policy for road tax in Turkey, using a genetic algorithm approach for demand estimation

This study deals, first, with estimation of transport demand based on Genetic Algorithm (GA) approach, and then deals with the evaluation of the road tax system in Turkey. It proposes an alternative road tax policy. The total transport demand is estimated based on population, Gross Domestic Product per Capita (GDPPC), and vehicle-number. Three forms of the Genetic Algorithm Transport Demand Estimation for Tax Revenues (GATDETR) are developed, of which one is linear, and the second and third are exponential forms of the mathematical expressions. The best-fit GATDETR model in terms of total minimum relative average errors between observed and estimated values are selected for future demand estimation. The evaluation of the road tax system and policy proposal is made based on estimated demand. The Distance-Based-Taxation (DBT) system is proposed in order to control highway transport. With the DBT system, some road users may wish to use railway. Thus, we re-organize the railways in order to meet the demand, but this requires new fund. The DBT system may help to create to this fund. It may also help to develop fair-taxation for the road users. Results show that the GA can be used to model transport demand and hence income tax in future transports planning. This study also suggests that planning the taxation in highway transport may help to ease funding problem of railway system.     

基于多维模型的电喷汽油机MAP图的数值生成

将DPIK点火模型和单步燃烧模型集成在K IVA-3V中,构建汽油机MAP研究的多维模型。对汽油机工作过程进行数值模拟,并以动力性、经济性和指示功为控制条件,结合试验数据对点火提前角和喷油脉宽进行优化。研究表明:用多维模型模拟的方法生成的MAP可以作为电喷汽油机的初始MAP。     

汽油车进排气系统降低噪声研究

提出了一种汽油车进、排气系统降低噪声方法,并基于Helmholtz共振原理,利用三维CAD软件Pro/E设计了进气谐振消声器。利用GT-power软件建立了整车、发动机、进气谐振器、排气消声器的联合模型。根据发动机工作过程,对排气消声器进行了改进设计。试验结果表明,采用进气谐振器和改进后的排气消声器,能够降低汽车加速行驶车外噪声以满足要求,且基本保持汽车输出功率不变。     

The asymmetric effects of gasoline prices on public transportation use in Taiwan

This study investigates the asymmetric effects of gasoline prices on public transportation use in Taiwan. The empirical results obtained are as follows. First, we verify that gasoline price is an important determinant of transit demand. Gasoline prices have significantly positive effects on bus and mass rapid transit (MRT) use. Second, MRT ridership is more sensitive than bus and railway ridership to gasoline price and income. In the face of oil prices escalation and economic growth, the MRT system should have higher priority in public transportation planning. Third, the effects of gasoline prices on bus and MRT use are asymmetric. Bus and MRT use increases faster when gasoline prices rise than it decreases when gasoline prices fall. The transit agencies should adjust operating strategies faster in the rising of oil prices than in the falling of oil prices. It is important for transit planning to use oil prices as signals and increase the flexibility of operation in dealing with the changes in ridership. Some strategies, such as enhancing the availability of transfer information and updating transit information timely, are helpful to move passengers efficiently.     

切诺基I—4汽油机燃烧系统的改进

针对美国切诺基I－4汽油机在我国使用较低辛烷值汽油的特定情况下出现爆震、排气温度高等问题，用天津大学发明的射流燃烧系统取代原机斜楔型燃烧系统。结果，改用新燃烧系统的I－4S汽油机，在使用较低辛烷值汽油时，动力、经济性能优于用同样汽油机的I－4，排气温度也显著降低，大大改善了发动机的使用条件。     

如何读取故障码

电子控制汽油喷射发动机控制系统的电脑内部，都装有一个故障自诊断系统，系统能在发动机运行过程中不断监测控制系统各部分的工作情况，并能检测出控制系统中大部分故障，将故障以代码的形式储存在电脑内。