基于EPM计费系统的应用

主要介绍了S12交换机采用的EPM新型计费采集系统，从技术上保证了话单自动定时采集的功能，从而代替了传统的人工输入人机命令DUMP到光盘上再脱机分拣出计费信息的方法。     

石板坡长江大桥复线桥工程专用水泥对混凝土性能影响研究

针对石板坡长江大桥复线桥结构和施工特点生产的专用水泥通过对水泥矿物组成及水化热的控制,对降低混凝土温升,提高混凝土体积稳定性和耐久性起到了直接、有效的作用。采用专用水泥配制的高性能混凝土具有良好的综合技术性能。     

确定焊接反变形的数值模拟及规律分析

焊接接头附近局部的加热及冷却使被焊结构产生残余应力及角变形.目前在船厂精度控制中,通常采用构件焊接后对某些部位进行火工校正的方法来控制残余角变形.文章提供了另外一种有效控制结构残余角变形的方法:对结构焊前施加弹性的反向变形.利用热弹塑性有限元法来模拟结构的焊接过程,并对不同板厚、不同热源的结构分别进行数值模拟,最终确定焊接结构的弹性反变形规律:焊接前施加弹性反变形的结构在焊接后角变形趋于零.     

自动售检票系统通用报文的封送及解封技术

自动售检票(AFC)系统是城市轨道交通运营的核心.介绍了AFC通信报文的模式和报文格式的抽象.沈阳地铁1号线及延伸线工程的通用报文封送、解封方案采用此方案后提高了AFC系统的设备兼容能力以及通信的健壮性、软件的复用能力,降低了AFC系统研发周期,从而整体上提高了系统集成能力.     

Parametric study of the main parameters influencing the catalytic efficiency of a diesel oxidation catalyst: Parameters influencing the efficiency of a diesel catalyst

This work studies the impact of five parameters: CO and HC engine-out emissions, space velocity, average value and profile of exhaust temperature, on Diesel CO and HC tail-pipe emissions. The first part of this work is conducted on a reactor and shows that both HC and CO light-off temperature increases with CO and HC input concentration. CO and HC initial concentration influence the adsorption/desorption capacities of HC only at high temperatures. Space velocity also influences CO and HC conversion efficiency. The second part of this work studies the impact of different combinations of HC and CO engine-out emissions on CO and HC conversion and tail-pipe emissions in the case of New European Driving Cycle. This part proposes that a Diesel oxidation catalyst must be mainly studied at the Urban Part of NEDC, as the CO and HC conversions are very high at the extra-urban part of NEDC. CO and HC conversion efficiencies are also dependent on exhaust temperature and catalytic volume. In the case of two different profiles of exhaust temperature with the same average temperature, CO and HC conversion efficiency is lower in the case of the smoother profile.     

3-D numerical and experimental analysis for airflow within a passenger compartment

People use cars so frequently that they always consider the air-conditioning, and thermal comfort of the driver and passenger when buying a new car. Therefore accurate simulation of the thermal performance of automobile air conditioners to improve human comfort has become increasingly important. In order to improve the thermal comfort of passengers, 3-D flow motion and thermal behavior within vehicles must be analyzed. In this paper, a numerical simulation was used to investigate thermal behavior in a vehicle. Because air temperature at an air vent is related to the cooling capacity of the air conditioner, the cooling capacity was calculated using ɛ-NTU (effective number of transfer unit) theoretical equations. Using the air temperature relationship between inlet and outlet vents as boundary conditions, a 3-D unsteady κ-ɛ turbulent model was used to give a transient analysis simulation of the temperature field and flow conditions in a vehicle’s passenger cabin. Cooling cycle analysis and conjugate heat transfer analysis at the inside surface of the cabin’s ceiling, floor and sides were also considered. The predicted temperature distributions in the vehicles passenger cabin were in good agreement with those obtained experimentally.     

Thermal design of automobile exhaust based thermoelectric generators: Objectives and challenges

The potential for thermoelectric power generation (via waste heat recovery onboard automobiles) to displace alternators and/or provide additional charging to a vehicle battery pack has increased with recent advances in thermoelectric material processing. In gasoline fueled vehicles (GFVs), about 40% of fuel energy is wasted in exhaust heat, while a smaller amount of energy (30%) is ejected through the engine coolant. Therefore, exhaust-based thermoelectric generators (ETEG) have been a focus for GFV applications since the late 1980s. The conversion efficiency of modern thermoelectric materials has increased more than three-fold in the last two decades; however, disputes as to the thermal design of ETEG systems has kept their overall efficiency at limited and insufficient values. There are many challenges in the thermal design of ETEG systems, such as increasing the efficiency of the heat exchangers (hot box and cold plate), maintaining a sufficient temperature difference across the thermoelectric modules during different operating conditions, and reducing thermal losses through the system as a whole. This paper focuses on a review of the main aspects of thermal design of ETEG systems through various investigations performed over the past twenty years. This paper is organized as follows: first, the construction of a typical ETEG is described. The heat balance and efficiency of ETEG are then discussed. Then, the third section of this paper emphasizes the main objectives and challenges for designing efficient ETEG systems. Finally, a review of ETEG research activities over the last twenty years is presented to focus on methods used by the research community to address such challenges.     

承台大体积混凝土水化热分析与施工控制

结合援孟加拉国中孟友谊六桥主桥承台设计与施工,利用Midas/Civil有限元计算分析软件对承台大体积混凝土水化热进行仿真分析,掌握水化热变化规律及其应力影响,据此指导现场施工控制。结果表明:仿真分析很好地反映了水化热变化规律及其应力影响,混凝土质量优良,没有出现温度裂缝,可供类似大体积混凝土设计与施工借鉴。     

高速公路路面特征的数字化表征与国道衰变谱系的研究

通过分析国内外在路面衰变谱系和路面数字化特征方面的研究情况,提出采用传感器、陀螺仪、激光扫描仪和数字相机等相关设备采集路面特征的数字化表征的高效的数据采集系统,从根本上解决路面衰变的定量分析与公路养护科学施工的不确定性问题,为交通安全管理提供技术支持。     

沥青混合料搅拌设备导热油炉的选择及使用

针对施工单位在选择使用沥青混合料搅拌设备导热油炉中存在的问题,提出合理选择使用导热油炉。