生态环境项目建设监理的机制研究

实行生态工程建设监理制,是加强生态建设的必由之路。该文针对现行生态工程监理机制中存在的问题,提出了搞好生态工程建设监理的一些对策和建议。     

Simulation of city bus performance based on actual urban driving cycle in China

This paper establishes the simulation model of a city bus on the basis of the EQ6110 bus prototype and its experimental data. According to the actual urban driving cycle, the fuel economy and the traction performance of the EQ6110 city bus have been simulated, and factors such as the driving cycle, the loss of power to engine accessories, the gear-shifting strategy, the fuel shut-off strategy of the engine, etc., which influence on the bus’s fuel economy, are also quantitatively analyzed. Some conclusions are drawn as follows: (1) driving cycles have a great influence on the fuel economy of a city bus; (2) under the typical urban driving cycle of the public bus in China, the engine fuel shut-off strategy can save about 1 to 1.5 percent of the fuel consumption; and (3) the optimized gear-shifting rules can save 6.7 percent of the fuel consumption. Experimental results verify that the fuel economy for the EQ6110 public bus is improved by 7.2 pecent over the actual Wuhan urban driving cycle of the current public bus in China.     

多级物流配送中心选址模型及计算机求解

介绍了构建多级物流配送中心选址模型的方法以及如何运用Excel中的规划求解工具对模型进行求解。     

基于Zigbee和GPRS的无线公交考勤管理系统

目前各城市公交公司主要采用人工打卡方式作为公交车考勤的主要手段,操作起来既不方便又费时。本文提出一种基于Zigbee技术和GPRS的无线智能公交考勤系统。该系统通过Zigbee无线传输技术实现车载终端与考勤打卡机通信,由打卡机记录下公交车的车号和时间,再通过GPRS技术传输到管理中心,实现对运行中的公交车进行监控和定位,具有方便省时,简单可靠,成本低等优点。     

Bolster spring fault detection strategy for heavy haul wagons

An on-board health monitoring system is proposed for heavy haul wagons in this paper including a signal-based fault detection and isolation (FDI) method and an on-line fault diagnose strategy. Such a system, to be feasible on freight wagons, must be sufficiently cheap and robust, hence the design assumes the constraint of using only two accelerometers mounted on the front left and right rear part of each carbody in a heavy haul train. This paper focuses on the detection of bolster spring fault conditions. The problem is made more complex by the modes of failure which might be expected in bolster spring nests. Types of spring failure are firstly identified and discussed covering situations of broken (shortening springs) and softening (individual spring loss from a nest or cross-section loss through corrosion). The effects of these faults and their detectability were investigated using simulations on straight and curved track and using a fully detailed model of a typical 40?t axle-load heavy haul wagon. The simulation results were then examined and compared using cross-correlation analysis and an FDI system was proposed. The FDI system introduced five possible fault indicators. Initial results indicated that it was possible to detect changes in bolster stiffness of ±25%. An on-line fault diagnoses strategy is proposed for bolster spring faults which only requires data from wagon monitoring during travel around sharp curves to detect and the occurrence of confirm faults. The functionality envisaged needs only a ‘once per trip’ monitoring site, such as a sharper curve, and is aimed at condition monitoring rather than the provision of alarms or comprehensive monitoring of all events.     

软土深部盾构开挖地层损失率对软土土拱效应的影响分析

盾构在软土深部地层进行主动开挖时,开挖所采取的地层损失率差异,会使得深部地层土体产生不同的位移以及应力变化,从而对软土深部地层的主动土拱效应产生差异影响。通过调整计算模型中的主动开挖土体范围,设定7种不同的地层损失率,建立地层损失与软土主动土拱效应比例之间的对应关系。通过分析可得： 1）盾构在4倍直径埋深条件下进行主动开挖时,在隧道上方1~2倍直径范围内形成主动土拱作用区域; 2）主动开挖所采取的地层损失率越大,开挖后拱顶处所受到的主动土压力荷载越小,土拱效应发挥越充分,且当地层损失率到达一定值时,盾构开挖所产生的主动土拱效应比例逐渐趋近于稳定临界值。     

广本雅阁轿车空调制冷系统间歇性制冷或不制冷的故障分析与排除

汽车空调是现代汽车的基本配置之一,而制冷系统则是空调系统中至关重要的系统之一。空调系统制冷效果差或完全不制冷是汽车使用中最常见的一种故障现象,也是汽车空调系统需要进行检修的主要原因。本文以一辆在用的最近检修的03款广州本田雅阁轿车为例,介绍汽车空调制冷系统的一个典型故障的原因分析、诊断与排除方法。     

氨氮废水处理技术发展现状

结合不同浓度氨氮废水的水质特点,评述了近二三十年来国内外主要的除氮技术,包括折点氯化法、吹脱法、离子交换法、化学沉淀法等物理化学法,以及传统生物处理技术和新型生物处理技术,如厌氧氨氧化、短程硝化反硝化、同时硝化反硝化等,并指出以上处理技术的适用条件及其优缺点和氨氮废水处理技术今后的发展趋势。     

基于博弈论的供应链金融监管合同奖惩研究

将银行和物流监管公司签订的监管合同中的奖惩条款为研究对象,基于博弈论探讨了监管方和借款方的博弈行为,找到了纯粹决策和混合决策的纳什均衡。通过算例,对比计算了有无奖励和惩罚时,混合决策的纳什均衡点的差异性:当在合同中增加奖励和惩罚措施时,纳什均衡的点将离原点更远,双方将以更大的概率选择合作。以此为基础,科学设立监管合同中监管项目的评价指标体系,明确监管奖惩措施,将有效降低供应链金融风险。     

城市桥梁与公路桥梁设计荷载标准对比与思考

城市桥梁与公路桥梁两者设计规范相比具有很多不同,其设计荷载标准也存在不同。分析两者的差异性,对比变化着的城市桥梁和公路桥梁的行业标准,多方面地对它们的设计荷载标准进行对比和思考,以促进更多桥梁设计的多元化发展,并不断与国际接轨,缓解城市交通压力,提高人们出行水平。