叉车车架线束设计的降成本

对于车架线束的降成本设计,本文从国产化、耗材的合理应用、设计的优化、元件选型及固定方式的优化5个方面进行了详细的阐述。实践证明,通过对线束做以上5个方面的改善,线束制作的成本会明显降低。     

Measuring foregone output under industry emission reduction target in the transportation sector

Numerous countries have implemented or are considering a range of policies to lower emissions from transportation. An analysis of the impacts of environmental regulation is a crucial issue, which has not been properly highlighted in the transportation literature, particularly in terms of the foregone output by such regulation. This study develops a novel DEA model that measures the foregone output when the industry emissions target is imposed. This model reflects the real regulatory process more appropriately than other models in that the authority in charge sets the emission reduction target first, and the transport operators respond to it. In addition, the model can test the industrywide impacts over a wide range of emission target values, which can help policy makers determine the optimal emission target. Finally, the proposed model was applied to the port industry in Korea. The results suggest that Korean ports can reduce their emissions by a maximum of 239,850 tons of CO₂, which accounts for 13% of the total emissions in 2010. The 13% reduction in emission, however, would result in $ 91,109,000 of foregone cargo traffic to the Korean economy. In addition, the foregone cargo traffic increases at much faster rate than the emission reduction rate. For example, the shadow price of emission differs by 2.25 times between the most moderate and strictest emission targets. This suggests that the government needs to impose moderate emission targets at the initial stages if it decides to minimize the regulatory impacts on the industry.     

公交站点生态化建设方案及可行性研究

结合生态城市和生态交通的理念,文章提出公交站点生态化发展策略及建设方案;从技术可行性、经济可行性和节能减排与社会效益评估三方面,对建设方案进行可行性研究。研究显示:建设方案技术上可行;建造费用为现有公交站的2~2.3倍,年运营维护费为现有公交站的1.3~1.4倍;但一个生态化站点一年内能提供电量700度左右,减少CO2排放量570~610 kg,局部降噪0.42~1.97 dB、降尘5~23 g、降温0.88~1.36℃,社会效益突出。     

基于双同步坐标的无刷双馈轴带发电控制系统

航运业的碳氮排放在全球排放中占较大比例,充分利用推进主机的剩余动力进行轴带发电,既可以减少碳氮的排放,又有助于提高燃料的利用效率。无刷双馈轴带发电系统摆脱了同步发电机型轴发的全功率变换器要求和有刷双馈型轴发维护要求高、安全性差的缺点。本文在dq0模型的基础上,通过双同步模型建立了针对功率绕组的磁场定向矢量控制方法,并设计了独立和并网发电两种运行模式下的控制策略。通过仿真和物理实验证明了建模方法和控制策略的有效性和可行性。     

基于EEOI的内河船舶航速优化研究

航速优化对船舶节能减排,提高能效水平具有重要意义.运用船舶动力学理论,以内河船舶为实例,规避理论模型中的不确定参数,利用实测数据确立主机油耗与航速关系模型,该模型考虑水流速度对油耗的影响,进而建立船舶EEOI与主机转速模型,并应用Matlab软件对模型进行优化求解.研究结果表明,在预定时间内,船舶主机采用优化得到的转速运行时,油耗节省0.8t,EEOI减少1.64%,提高了船舶能效水平.      

基于粗糙集的机车牵引变流器故障诊断方法

利用粗糙集对故障特征数据库中的数据进行处理和约简,过滤冗余属性,提取出有效的故障模式规则.依据这些规则,对新加入数据进行判别并归类,识别出故障的类型,依此找到故障的原因并排除故障,从而使机车实现“状态修”成为可能.从实验结果可知,基于粗糙集的故障诊断方法非常有效,可以很大程度减少数据处理的工作量.     

三维强度折减法在边坡抗滑稳定分析中的应用

针对黄金坪水电站进水口边坡1570m高程以上潜在不稳定块体,在对强度折减法适用性进行验证的基础上,采用三维强度折减法进行了稳定性分析．研究结果表明：该块体三维效应明显,主要表现在侧边界的阻滑作用．在实际工程中,对于三维效应明显的边坡,可以适当考虑边坡的三维效应,从而保证支护措施的经济合理．     

高承压水条件下地铁深基坑减压降水研究

为降低高承压水深基坑工程的突涌风险,在某地铁深基坑换乘站建设过程中,通过现场抽水试验及沉降监测,借助数值模拟为基坑减压降水进行方案优化.获取了承压含水层的水文地质参数,分析预测了三维渗流场及周边沉降的时空分布规律,提出了合理的降水优化方案,对类似工程具有借鉴意义     

Aerodynamic simulation of evacuated tube maglev trains with different streamlined designs

Based on the Navier-Stokes (N-S) equations of incompressible viscous fluids and the standard k-ε turbulence model with assumptions of steady state and two dimensional conditions,a simulation of the aer...     

一种改进的最小属性约简算法

最小属性约简是粗糙集理论中的一个重要内容,通过对属性约简算法的研究,指出基于U/{a}划分的最小属性约简算法中的不足,并提出了一种改进的最小属性约简算法.该算法以基于等价类的方法对论域进行压缩,有效地降低了算法的空间复杂度,用基于核的方法求解最小约简,从而保证可获得最小约简.实验结果表明,该算法具有复杂性低、存储空间小和效率高的特点,是一种有效的最小属性约简算法.