考虑围岩蠕变特性的TBM隧道管片衬砌受力特性研究

为研究深部高地应力岩层中修建TBM隧道时管片衬砌结构的力学行为,以某深埋TBM工法隧道为研究对象,建立基于围岩蠕变和管片分块效应的衬砌-围岩复合模型,研究考虑时间效应下管片衬砌的受力特性。结果表明:考虑围岩蠕变效应下管片衬砌受力表现出明显的时间效应。随着围岩蠕变时间的延长,管片衬砌的形变、内力和接缝张开量均呈现两阶段增长,具体表现为前期呈线性增长,后期增加趋缓。洞周围岩应力经历三阶段变化,即先减小后增大直至稳定。围岩蠕变时间为100年时,管片衬砌的内力和形变量均接近极限值。研究结果可为深部高地应力且考虑围岩蠕变效应下的TBM隧道衬砌结构设计提供参考。     

应用新型涂料、促进绿色造船

推广应用有机硅低表面能防污涂料、水性涂料、厚浆型涂料、通用底漆,降低甚至消除船舶涂料中有害物质对人和环境负面影响,减少有机废料的产生,节省各种资源的消耗,促进绿色造船的发展。     

积极开展牵引电气设备的绿色设计研究

阐述了开展绿色设计的重要意义,介绍了资源最佳利用原则、环境设计原则、产品结构设计原则、社会经济效益最佳原则以及绿色设计技术和方法的研究等.     

A high order linear model for the prediction of internal lee waves at the main sill of the Strait of Gibraltar

A linear theory for the physical fields in the water column under the action of large amplitude internal lee waves at the main sill of the Strait of Gibraltar is developed. The procedure is a combination of the perturbation and normal modes methods in order to study steady resonant conditions. The lowest order linear approach of the methodology resumes the Taylor–Goldstein equation, which can reconstruct the main features of the observed fields but the high order approach gives the finest structure and sometimes the largest contributions. The role of the non-linear terms is investigated up to the second order taking into account the non-linear interactions between modes, leading to an effective reconstruction of the whole water column for the velocity field.     

现代企业内部控制环境浅析

内部控制环境是现代企业内部控制的首要要素,文章首先分析了影响现代企业内部控制环境的因素,然后提出了完善现代企业内部控制环境的建议与措施。     

2020年世界船舶市场评述与2021年展望

回顾了2020年世界经济、航运、造船市场,并对2021年船舶市场进行展望。2020年新冠肺炎疫情席卷全球,全球经济整体呈现负增长,导致航运各细分市场情况迥异,除集运市场年底火热外,其他市场均处于低迷状态。新船交付量整体大幅回落,与去年同比减少约31%,市场出现大面积撤单现象,仅海工市场基本面向好。新船建造市场受疫情影响,与2019年同期相比下跌约11%,散货船是今年交付量中唯一呈现增长的船型。2021年预计世界经济同比大幅反弹,航运市场需求将强于供给,市场形势总体将优于2020年;同时,考虑到疫情对市场的影响效应短期持续,预计世界船舶市场将逐步趋于理性,主要船型的新船订单量将朝着长期均衡方向逐步恢复增长,并且绿色和智能依旧是未来的大方向。     

铁路绿色施工节地与土地资源保护措施评价

为了更好地促进绿色铁路建设,进而促进国家实现建设资源节约型环境友好型社会的目标,必须对施工阶段铁路的节地与土地资源保护措施进行评价。通过研究相关技术标准及铁路施工特点,建立一套完善的铁路绿色施工节地与土地资源保护措施评价指标体系。然后,利用三角模糊数层次分析法确定各指标权重,应用灰色聚类法确定评价指标体系的综合绿色等级。最后,结合实例证明三角模糊数层次法与灰色聚类法结合可以对铁路绿色施工节地与土地资源保护措施进行很好的评价,并能找出铁路施工阶段节地与土地资源保护的不足之处并进行改进。     

内燃机振动动力式主动吸振器的研究

振动主动控制技术具有减振效率高，有效减振频率范围度，反应敏捷等优点，在机械振动领域具有广泛的应用前景。在一台四缸柴油机上进行振动主动控制的研究，使用主动控制技术控制动力吸振式的频率，使其能足够发动机的主动振动频率，并保持最佳状态，从而有效地抑制发动机的振动。     

车身内部布置CAD系统及其应用

介绍了自行开发的汽车车身内部布置的ＣＡＤ系统，并就系统在设计中的应用了说明。该系统是在通用图形软件基础上进行二次开发而成的，以ＳＡＥ标准，ＥＥＣ标准及为主要依据，将ＣＡＤ技术运用到车身内部布置设计中。     

Transport energy consumption in mountainous roads. A comparative case study for internal combustion engines and electric vehicles in Andorra

This paper analyses transport energy consumption of conventional and electric vehicles in mountainous roads. A standard round trip in Andorra has been modelled in order to characterise vehicle dynamics in hilly regions. Two conventional diesel vehicles and their electric-equivalent models have been simulated and their performances have been compared. Six scenarios have been simulated to study the effects of factors such as orography, traffic congestion and driving style. The European fuel consumption and emissions test and Artemis urban driving cycles, representative of European driving cycles, have also been included in the comparative analysis. The results show that road grade has a major impact on fuel economy, although it affects consumption in different levels depending on the technology analysed. Electric vehicles are less affected by this factor as opposed to conventional vehicles, increasing the potential energy savings in a hypothetical electrification of the car fleet. However, electric vehicle range in mountainous terrains is lower compared to that estimated by manufacturers, a fact that could adversely affect a massive adoption of electric cars in the short term.