Relationships between characteristics of motorcycles and hydrocarbon emissions in Taiwan: A note

Taiwan’s inspection and maintenance (I/M) programs identifies high-emission motorcycles but, although these help reduce air pollution, they have been criticized for being cost-ineffective. This study examines the relationship between characteristics of motorcycles and hydrocarbon emissions in the Central Air Quality Basin of Taiwan. It is shown that engine size and type, age and manufacturer of a motorcycle significantly affect HC emissions. Larger-size engines emit smaller amounts of HCs; whereas older motorcycles emitted greater amounts. In addition, two-stroke-engine machines produced significantly higher HC emission levels than four-strokes. Variations in HC emissions testing are a result of various I/M testing locations and efficiency may be improved by modifying these.     

预应力混凝土连续梁桥线形控制影响因素研究

文章结合沪宁城际高速铁路某预应力连续梁桥工程实例,采用有限元计算软件,分析了混凝土弹性模量、混凝土容重、预应力、温度、混凝土收缩徐变等因素对该桥主梁线形控制的影响,并提出了相应的控制措施。     

Automated shunting of rail container wagons in ports and terminal areas

The development of intermodal container transport is hampered in part by the cost associated with the shunting of trains in marshalling yards, inland and port railway terminals. Many new technologies have been developed in the past decade, but have still not been applied because of high capital investment costs, lack of sufficient market demand and uncertain rates of return. The key for increasing the competitiveness of intermodal container transport by rail is the operation of heavy haul container trains between port and inland railway terminals more frequently with fast, flexible and automatic transhipment, shunting and coupling of container wagons. The operation of self-driven railcars equipped with automatic centre coupling on terminal tracks, which can also be train-hauled on conventional hinterland railway lines, would enable a reduction of shunting and transhipment time and costs in intermodal container terminals by more than 30%.     

高速公路互通改扩建线形布设难点及处理方法研究

互通式立交改扩建是高速公路改扩建工程的重点和难点,做好其改扩建线形布设非常关键。文章采用比较性分析与规律性总结相结合的方法,分析了高速公路互通式立交改扩建工程线形布设的主要影响因素和普遍遇到的难点与处理方法,并以呼包高速公路呼和浩特市互通改扩建工程为实例,介绍了其改扩建线形布设的难点与解决措施。     

探讨预测路外伤亡事故的方法

分析了几种预测路外伤亡事故的方法，其中加权综合预测法考虑了两种或两种以上预测结果的权重，因此可减少预测误差，提高预测的准确性，是一种值得推广的预测方法。     

On Diophantine Equation X（ X ＋ 1 ） （ X ＋ 2） （ X ＋ 3） = 14Y（Y＋1）（Y＋2）（Y＋3）

The Diophantine equation X(X+1)(X+2)(X+3)=14Y(Y+1)(Y+2)(Y+3) still remains open.Using recurrence sequence,Maple software,Pell equation and quadraric residue,this paper proved it has only two positive integer solutions,i.e.,(X,Y)=(5,2),(7,3).     

Ⅲ-Ⅴ族三结抗辐照太阳电池结构的改进初探

文章介绍了Ⅲ-Ⅴ族叠层太阳电池抗辐照设计的基本思路,提出了Ⅲ-Ⅴ族叠层抗辐照太阳电池的两种改进结构p-i-n结构和线性掺杂结构,并探讨分析了这两种结构的物理原理和在抗辐照性能上的优劣,为进一步改善其抗辐射效应作了颇有意义的基础工作。     

直线感应电机屏蔽层涡流场和开孔分析

从直线电机屏蔽层出发,研究屏蔽层涡流场的分布、不同频率对屏蔽层涡流损耗的变化情况以及屏蔽层开孔是否带来涡流集中,并将矢量电位法计算和有限元分析结果与试验数据进行对比,验证分析的正确性。     

合龙方案对多跨连续梁桥施工监控的影响分析

多跨连续梁的合龙顺序对结构成桥累计位移和内力有较大影响,以1座（48+4×80+48）m预应力混凝土连续梁桥为例,根据不同的合龙方案确定3种工况,对不同工况下的桥梁结构建立不同结构体系转换的施工阶段分析有限元模型,分析合龙顺序及合龙期间的预应力张拉阶段对施工阶段的预拱度及成桥内力的影响,对比分析多跨连续梁桥合龙口两端产生较大位移差的原因。提出多跨连续梁桥线形监控难度的主要影响因素为累计位移最大值和合龙口两端的累计位移差。结果表明,合龙顺序对梁体施工中的预拱度设置量影响较大,特别是不同结构体系下预应力张拉效应差别较大,合理的合龙顺序和分批分阶段张拉预应力可降低施工过程中线形监控的难度,根据分析结果提出合理的合龙顺序建议。     

地铁车辆直线电机气隙在线检测系统结构

气隙在线检测系统是集数据采集、分析、处理与实时通信于一体的计算机测量系统。作为直线电机地铁车辆的维护设备之一,当车辆通过系统时,其可以实现自动辨别车号、计算车速、记录轴数、测量气隙高度等功能,并通过计算机内部设备的判别模型,对超限数据进行报警。