水泥混凝土路面碎石化层应力强度因子有限元分析

为比较是否碎石化对加铺后沥青路面结构应力的影响,本文从断裂力学入手,借助有限元软件,按等参八节点二维平面应变单元分析了两者在沥青加铺层情况相同时层底的应力强度因子。经对比分析,两者的Ⅰ型应力强度因子差别很大,而Ⅱ型应力强度因子基本相同,表明碎石化后沥青加铺层层底具有更好的受力特性,与不破碎直接加铺相比,能显著降低沥青加铺层底反射裂缝的可能性。这表明碎石化工艺对旧水泥混凝土路面的处治能满足加铺要求,达到了工艺处理的目的。     

新的改性沥青设备与加工技术

通过对沥青改性方法的研究 ,基于提高改性沥青单位小时产量的目的 ,探索出利用高速剪切和二次泵技术实施沥青改性。这种加工技术突破了以往沥青改性采用的“胶体磨”技术 ,适用范围广 ,可加工不同种类的改性沥青 ;采用该种加工技术提高了生产效率 ,产品的技术指标满足甚至超过规范要求。通过研制出的改性沥青生产设备制备出 PE、SBS、化学网构改性沥青等 ,而且将这几种改性沥青已应用于实体工程。     

柴油机管理系统开发与设计方法的研究

根据国内外柴油机电控技术开发与设计的经验，阐述了开发与设计柴油机管理系统所采用的最新技术与方法。通过新技术与新方法的运用，提高整个系统功能控制和以数管理的性能，最终达到改善柴油机经济性，动力性及排放等的目的。     

发动机缸盖内部冷却水腔的设计与流动数值模拟

讨论了发动机缸盖内部冷却水腔设计的发展趋势及要求 ,应用自行开发的三维流动数值模拟计算软件对冷却水腔内的流动情况进行了数值模拟。     

大跨度钢管桁架无柱雨棚施工技术

重庆江北火车站大跨度钢管桁架无柱式雨棚,高14m,长540m,建筑面积达56230m2。结构工程跨度大,场地条件复杂,施工制约因素多,质量要求高。对主桁架等大型构件首次采用加工厂下料、现场加工制作、现场拼装、整体吊装的方案。详述了主桁架的吊装、焊接等工艺和施工控制措施。通过合理选择施工方案,严格按照工艺要求,合理安排施工程序,保证了工程如期保质保量的完成。     

A regional railroad network optimization model for coal transportation

A regional railroad network is presented to evaluate the system's response to increased coal traffic. An optimal, multimodal, coal-shipping pattern is developed for the study region to minimize total costs and to efficiently use the existing network. A two-stage, general model allocates resources among demands and then assigns flows to the network according to efficiency criteria. The model is sufficiently general to permit modification for specific needs, assumptions and data. Government agencies and industries can apply the model in resource allocation decisions and transportation policy analysis.     

堆场和道路智能照明的节能与推广

阐述高压钠灯功率、亮度和寿命与电压的关系,分析能对电网电压波动快速响应,闭环自动稳压、可控平缓调压的智能装置的工作原理和节能模式,应用它在软启动和运行时,灯具电流几乎恒等于额定电流,因而,不仅可以大量节约电能,还可以延长灯具的使用寿命,并探讨它在集装箱堆场应用集中远程控制的方案。     

离焦对光测影响的初步研究

分析离焦产生机理,并通过实验的方法,定量地分析离焦对光测的影响.有助于解决在进行大视场测量时,特别是对大视场内的运动目标位置进行测昔时,在什么位置标定既方便又不影响测量精度的难题.     

Computer Simulation of Thermal-Mechanical Processing

AlterationIntroductionThereisastrongini6ractionamongtemPetalrefield,strCssfield,andmicrosttuctutulaltOrationinm8terialsduringtheirhotworking[l'2].Especiallyduringthecoolingprocess,inwhichtemPeratorechangnsgreatly,intendionsbecomemorecomplexbecauseoftransformationoccurmnce.Duringthehotdeformation,thingswillaPpearsuchas:a.hotdeformation,relatedtostressfieId,changesessentiallytheshaPeofmaterialsandcausesthevariationofthecontactstatebetWeenthedieandsample,resultinginchangeofthethermalboundnyco…     

The use of polycyclic aromatic hydrocarbons as a particulate tracer in the water column of Gaoping (Kaoping) Submarine Canyon

Time-series samples of settling particles were collected in the water column of Gaoping (formerly spelled Kaoping) Submarine Canyon (KPSC) with two sediment traps on taut-line moorings deployed at two different depths (60 and 280 m) between May 26 and June 27, 2004. Average total polycyclic aromatic hydrocarbon (PAH) concentrations of upper and lower trap array samples were 310 ± 61 ng g^− 1 dw (range: 200–440) and 240 ± 36 ng g^− 1 dw (range: 180–290), respectively. Principal component analysis results suggest that PAH sources in the trap-collected particles included diesel vehicle/coal burning, diagenetic sources, and petroleum release. PAH downward fluxes based on settling particles were estimated to be 12–44 μg m^− 2 d^− 1. These values are higher than those reported in the literature for most coastal areas. During the sampling period, both traps were significantly tilted by tidal current and fluctuated vertically. The upper traps experienced greater vertical movements, thus their particle characteristics (e.g., POC, particle mass, and fine particle fraction) varied more than those of the lower traps. Hourly depth variations of the tilted sediment trap array were echoed by the corresponding total PAH concentrations. Moreover, the PAH composition of the collected particles was related to the flow direction and speed. These observations suggest that PAHs can be used as an effective chemical tracer for the transport of terrestrial and marine particulates in a complex aquatic environment like Gaoping (Kaoping) Submarine Canyon.