Establishing car sharing services in rural areas: a simulation-based fleet operations analysis

Today, car sharing represents a generally accepted and widespread mode of individual transport. Car sharing providers operate their fleets effectively in many cities around the world. Surprisingly, rural areas don’t seem to have been considered in provider’s current expansion strategies. However, studies suggest that car sharing would have the greatest impact on improving sustainability and reducing traffic if it were offered nationwide. In this paper, we analyze the factors that prevent car sharing enterprises from developing their services in rural regions. Supported by a simulation model, we elaborate strategic implications on how to deal with potential hindrances such as lower demand or longer driving distances. For this purpose, a symbiosis of urban and rural car sharing services was analyzed. Our findings indicate a certain feasibility of rural car sharing development, while highlighting the positive effect it could have on car sharing demand in urban areas.

     

Potential of Real-Time Cylinder Pressure Analysis by Using Field Programmable Gate Arrays

In this paper, a Field Programmable Gate Array (FPGA) was used to implement a real-time cylinder pressure analysis. The goal of the project was to improve the accuracy of calculated heat release and center of combustion calculations to enhance the precision of engine control functions. Compared to today’s real-time pressure analysis systems, several additional physical effects were taken into account for this objective. The wall heat transfer was calculated based on the approach published by Hohenberg. A chemical equilibrium with six substances was assumed for the mixture composition and a real-time calculation method was developed. Furthermore, a two-zone model was adapted and implemented for this realtime analysis. The validation of the results and the rating of the improvement in precision were based on GT-SUITE simulation results as an offline reference tool. Compared to state-of-the-art analysis systems, it was possible to reduce the average error of the center of combustion position from 1.6° to 0.5° crank angle (CA) by taking the investigated effects into account. Moreover, it was possible to significantly reduce the time required for the calculation from one complete combustion cycle to 0.2°CA at an engine speed of 3,000 rpm by using a continuous calculation method on the FPGA. This led to an additional improvement of the ability to control the engine, especially under highly dynamic operation conditions.     

基于玻璃纤维锚杆微应变测试的软岩隧道松动圈测试技术及应用

为解决软弱破碎围岩地层隧道松动圈测试的难题,分析现有松动圈测试技术现状,以全长黏结型玻纤锚杆为载体,提出一种适用于破碎软岩隧道的围岩松动圈测试技术。该测试技术以锚杆微应变变化趋势为基础,结合锚杆中性点理论,可大致确定围岩松动圈范围。将该技术应用在大（理）临（沧）铁路杏子山隧道破碎炭质板岩大变形地段进行验证,结果表明： 全长黏结型玻璃纤维锚杆在松动区可与软弱破碎围岩有效协调变形,锚杆微应变变化趋势与中性点理论相符,采用锚杆微应变变化趋势表征围岩松动圈范围合理可行。同时该技术测试精度可通过调整沿锚杆长度粘贴应变片的密度来控制,有效弥补传统物探松动圈测试技术对岩体要求高的问题,在软弱破碎围岩地层中具有较好的操作性和适用性。     

Physical processes in wheel–rail contact and its implications on vehicle–track interaction

Friction within the wheel–rail contact highly influences all aspects of vehicle–track interaction. Models describing this frictional behaviour are of high relevance, for example, for reliable predictions on drive train dynamics. It has been shown by experiments, that the friction at a certain position on rail is not describable by only one number for the coefficient of friction. Beside the contact conditions (existence of liquids, solid third bodies, etc.) the vehicle speed, normal loading and contact geometry are further influencing factors. State-of-the-art models are not able to account for this sufficiently. Thus, an Extended-Creep-Force-Model was developed taking into account effects from third body layers. This model is able to describe all considered effects. In this way, a significant improvement of the prediction quality with respect to all aspects of vehicle–track interaction is expected.     

从凸缘连接到对焊接头的飞跃:应用于汽车制造业的激光器

如果将对焊接头取代于横梁、底座和管道的凸缘和搭接接头以及其他车身上结构件的焊接,能节省多少材料、重量和燃料?当粘合车门钣金件和汽车框架的密封胶水重量包含在总重量中,这个问题就非常值得一提。而这个问题取决于零部件。如果不再使用凸缘搭接,减少的重量能高达几公斤,同时也能节省每部分的安装空间,约高达8～16mm。搭接凸缘设计是两项极具现代车身制造特色的发明逐渐成熟的产物。第一项是诞生于1877年的电阻焊,它是快速、高效和实用的焊接加工方法。第二项是1 954年应     

高职院校"形势与政策"课规范化和制度化建设的初探

《形势与政策》课是高校思想政治理论课的重要组成部分，是每一位大学生的必修课。因此要以规范化制度化建设为重点，加强形势与政策课教学管理。将教学任务编入教学计划是《形势与政策》课规范化制度化建设的基础。加强和提高师资队伍水平是《形势与政策》课规范化制度化建设的关键。开展教学改革是《形势与政策》课规范化制度化建设的生命。     

水下潜器改进S面控制及控制系统仿真(英文)

S surface controllers have been proven to provide effective motion control for an autonomous underwater vehicle (AUV). However, it is difficult to adjust their control parameters manually. Choosing the optimum parameters for the controller of a particular AUV is a significant challenge. To automate the process, a modified particle swarm optimization (MPSO) algorithm was proposed. It was based on immune theory, and used a nonlinear regression strategy for inertia weight to optimize AUV control parameters. A semi-physical simulation system for the AUV was developed as a platform to verify the proposed control method, and its structure was considered. The simulation results indicated that the semi-physical simulation platform was helpful, the optimization algorithm has good local and global searching abilities, and the method can be reliably used for an AUV.     

THE EUKARYOTIC EXPRESSION OF HUMAN PERFORIN PROTEIN AND THE ESTABLISHMENT OF HYBRIDOMAS PRODUCING ANTI-HUMAN PERFORIN PROTEIN

Perforin is expressed mainly in activated cyto-toxic T lymphocytes (CTLs ) and natural killer(NK) cells. The human perforin gene has beencloned. The full length of its cDNA is l668bp, andthe mature HP protein is made up of 534 aminoacid residues with a molecular weight of 66Kd~75Kd. In CTLs and NK cells, perforin is stored incytoplasmic granules and is a major effector of cy-tolysis by these cells. Upon granules releasing,perforin monomers insert into the plasma mem-branes of target ce…     

新型含1H-吡唑的新型双杂环化合物的合成

以乙酰乙酸乙酯和芳甲酰氯为原料，合成相应的β-酮酸酯，在乙醇钠／碘的作用下实现二聚偶联反应得到1，4-二酮化合物，然后与水合肼反应，得到两个新型含1肺吡唑的双杂环化合物，其结构经’HNMR、Ms及IR证实。     

低地板轻轨车的"积木"式模块设计

以低地板轻轨车ＣＯＭＢＩＮＯ车体承载结构为实例，阐明了采用“积木”式模块设计的优点。