杭州湾跨海大桥南岸滩涂引桥上部结构设计

介绍杭州湾跨海大桥南岸滩涂引桥50 m箱梁,采用整体预制、梁上运输、整孔架设的施工方案,以及施工设计阶段中遇到的困难与采取的措施。     

关于C50结构砼的适用配比研究

对C50混凝土配合比设计中的设计方法、注意事项及施工中的控制重点提出一些看法.     

Viewpoints of adults with and without Autism Spectrum Disorders on public transport

BackgroundPublic transport is low cost, allows for independence, and facilitates engagement and participation for non-drivers. However, the viewpoints of individuals with cognitive disabilities are rarely considered. In Australia, the prevalence of Autism Spectrum Disorders (ASD) is approximately 1% and increasing. Many individuals with ASD do not possess a driver’s licence, indicating that access to public transport is crucial for their independence. However, at present, there is no research on the opinions of adults with ASD on public transport.AimTo identify the viewpoints of adults with ASD regarding the barriers and facilitators of public transport usage and their transportation preferences, and to contrast these against the viewpoints of neurotypical adults.MethodsQ method was used to identify the viewpoints of both participant groups on public transport. Participants consisted of 55 adults with a diagnosis of ASD and a contrast group of 57 neurotypical adults. Both groups completed a Q sort task which took place in either Perth or Melbourne, Australia.ResultsThe most prominent viewpoint indicated that both groups preferred to use public transport over driving and believed that it supported their independence. This viewpoint also indicated that both groups preferred to use electronic ticketing when using public transport. Interestingly, the second most prominent viewpoint indicated that both groups preferred to drive themselves by private car rather than use public transport.DiscussionIt appears that the viewpoints of adults with and without ASD regarding public transportation were largely similar. However, questions arose about whether the preference for public transport in the ASD group may be more a result of difficulties obtaining a driving licence than a deliberate choice. The only barrier specified by adults with ASD related to crowding on public transport. Safety and convenience in relation to location and timing of services were barriers reported by neurotypical adults.     

Changes in the external costs of freight surface transport In Spain

This paper studies the external costs of surface freight transport in Spain and finds that a reduction occurred over the past15 years. The analysis yields two conclusions: trucks have experienced a reduction in external costs, and rail has lower externalities. The external costs of road freight transport decrease between 1993 and 2007 (44%). The external costs of rail freight increase by 12%. During this period, the external costs of road freight related to climate increase by 16%, oppositely than those from air pollution and accidents (51 and 44%). The external costs of rail related to pollutant emissions and climate increase by 4% and 43%. Oppositely, the external costs related to accidents decrease by 27%. Road freight generates eight times the external costs of rail, 2.35 Euro cents per tonne kilometre in 2005 (5.6% accidents, 74.7% air pollution and 19.7% climate) vs. 0.28 (13.4% accidents, 53.9% air pollution and 32.7% climate).     

Q235钢焊接熔合区在混合菌共同作用下的腐蚀行为

通过观察腐蚀形貌,测量极化曲线和阻抗谱,研究了Q235钢熔合区在SRB和V.natriegens共同作用下的腐蚀行为。研究表明,熔合区的腐蚀程度,单一菌溶液中,SRB大于V.natriegens,混合菌溶液大于单一菌;混合菌溶液中SRB和V.natriegens表现出协同作用,加速试样的腐蚀;试样的耐腐蚀性能,熔合区小于焊缝区小于母材区。     

中国公路隧道围岩分级法和挪威Q值法及南非RMR法对应关系探讨

该文以德黑兰北部高速公路项目的工程实践为基础,总结了中国公路隧道围岩分级法和挪威Q法及南非RMR法对应关系,为隧道围岩分级的中外技术交流建立共同的平台。     

C50混凝土配合比设计注意事项探析

C50及以上强度的混凝土对桥梁施工有着至关重要的作用。原材料选择主要包括集料、水泥和外加剂的选择。C50混凝土配合比设计需计算C50混凝土比配合比并确定试拌混凝土基准配合比。     

Productive efficiency of public and private solid waste logistics and its implications for waste management policy

This paper measures the productive efficiency of municipal solid waste (MSW) logistics by applying data envelopment analysis (DEA) to cross-sectional data of prefectures in Japan. Either through public operations or by outsourcing to private waste collection operators, prefectural governments possess the fundamental authority over waste processing operations in Japan. Therefore, we estimate a multi-input multi-output production efficiency at the prefectural level via DEA, employing several different model settings. Our data classify the MSW into household solid waste (HSW) and business solid waste (BSW) collected by both private and public operators as separate outputs, while the numbers of trucks and workers used by private and public operators are used as inputs. The results consistently show that geographical characteristics, such as the number of inhabited remote islands, are relatively more dominant factors for determining inefficiency. While the implication that a minimum efficient scale is not achieved in these small islands is in line with the literature suggesting that waste logistics has increasing returns at the municipal level, our results indicate that waste collection efficiency in Japan is well described by CRS technology at the prefectural level. The results also show that prefectures with higher private-sector participation, measured in terms of HSW collection, are more efficient, whereas a higher private–labor ratio negatively affects efficiency. We also provide evidence that prefectures with inefficient MSW logistics have a higher tendency of suffering from the illegal dumping of industrial waste.     

机车信号50Hz干扰问题分析与探讨

在高速铁路中,机车信号起着指示高速列车运行的重要作用,但有时会受到干扰的影响。根据轨道电路机车入口电流和机车牵引电流传输特点,分析机车信号中出现50Hz干扰的原因,总结出查找此类问题的方法,确保铁路运输安全。     

海洋钻井平台桩腿齿条板与半圆板焊接工艺试验

针对400ft钻井平台桩腿齿条板与半圆板焊接全熔透的新要求,笔者通过试验和不同施焊方法相结合的方式分析了组对间隙和清根与否等因素对Q690E试板接头根部熔深的影响。结果表明,无论采用何种焊接方法,反面清根后施焊,接头熔合状况均良好,且采用实芯焊丝比药芯焊丝接头熔深大。正面气保焊打底,反面不清根采用气保焊施焊,接头熔合不良;而反面采用埋弧焊施焊,接头可实现熔透,但工艺还有待优化,以避免结晶裂纹的产生。