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考古发现良渚古城城墙底部铺有一层块石,为了搞清良渚人铺设这层垫石的目的和作用功效,利用Geostudio软件开展有限元计算,定量分析铺设垫石对增强城墙稳定性、加快排水固结、减小沉降及水平变形量三方面的作用。计算结果表明,铺设垫石后,地基表面形成了一层强度较高,模量较大的垫层,增强了城墙的抗滑移能力,使其边坡稳定系数提高10.1%~19.0%;铺设垫石层后,100 d时间内,地基的平均固结度可提高10.8%~14.9%,允许填筑速度可从8 d提高到6 d;铺设垫石还可以起到应力扩散作用,使地基最大沉降减小47.1%,最大水平位移减小39.2%,这有利于减少填筑土方量。 相似文献
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A suitable model that enables the analysis of dynamic relationships between transport systems is important for managers to make real-time reaction strategies. This study proposes an autoregressive distributed lag modeling approach that can point a way to interpret the long- and short-term relationships between intercity transport systems. To test the applicability of the approach with regard to evaluating the dynamic competitive relationships between intercity transport systems, an empirical study sample is adopted in evaluating competition between high-speed rail (HSR) and intercity bus services. The results indicate that HSR has a long-run impact on intercity bus transport and the intercity bus transport market is positively affected by its previous operations and negatively influenced by the previous performance of HSR. However, in the short-run, the current period performance of HSR positively affects the intercity bus transport market. 相似文献
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文章分析一种新型超机动飞碟形的自主式潜水器—水下直升机的运动稳定性,以实现其在海底复杂的作业任务。采用AYASYS-CFX计算流体力学的仿真模拟技术,分析飞碟形的水下直升机在水平面的机动性和垂直面的运动稳定性等水动力关键技术问题。采用多种数值水池模拟的方法,包括直(斜)航运动和圆池旋臂运动等模拟方法,以计算水下直升机的水动力的稳定性导数、水动力(矩)、随攻角变化的压力中心和阻升比等。在设计航速1 kn的情况下,采用Routh线性水动力导数组成的运动稳定性数学模型,分析其水平及垂直面上的运动稳定性。计算结果说明,水下直升机在水平面上回转运动具有战术直径接近零的超机动能力,同时,在垂直面上具有优于传统鱼雷形潜水器的运动稳定性。 相似文献
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Pin‐Fenn Chou 《运输评论》2013,33(6):741-758
Abstract This study empirically investigated service quality, switching costs and customer loyalty from home‐delivery services' customers' perceptive. With regard to service quality attributes, findings indicated that customers were most satisfied with ‘range of delivery’, followed by ‘seldom loses parcels’, ‘invoice accuracy’, ‘prompt and reliable collection’ and ‘delivery by due time’. They were least satisfied with competitiveness of price. A structural equation modelling (SEM) approach was employed to analyse the impact of service quality and switching costs on customer loyalty from customers' perspective. Results revealed that service quality positively influenced switching costs and customer loyalty, and switching costs had a positive effect on customer loyalty. Investigation of the moderating effect of switching costs on the relationship between service quality and customer loyalty indicated that it was significantly important. Theoretical and practical implications of the findings for firms providing home‐delivery services are discussed. 相似文献
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该文研究了回收橡胶复合改性剂(简称RRCM)对沥青三大指标、沥青抗老化性能、沥青混合料路用性能的影响。结果表明:RRCM的加入使得沥青针入度降低,延度增加,软化点提高,当量软化点提高;热氧老化是沥青老化的主要原因,RRCM可提高沥青的抗老化性能,提高沥青混合料的路用性能。综合比较分析,推荐采用1~#RRCM。 相似文献
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<正>1997年底,在结束了与广汽的合作探讨后,年产量已接近10万辆的柳州微型车厂进入到了欧宝小组的视野。虽然通用对柳微的印象很好,却被告知柳微将被并入东风,无意合作。既然如此,"中中外"合资的典范——上汽通用五菱又将从何而来?合作又是如何从双方变为三方,最终实现共赢的呢?通用的中国低端市场战略1997年底,欧宝小组结束与广汽的合作探讨后,了解到柳州五菱的产量排行位列全国前十,善能便带领欧宝小组前往南宁,由广西自治区政府陪同到柳州参观 相似文献
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1 前 言IHIMARINE UNITED股份有限公司(以下简称为IHIMU) ,以“SUPERZEARTH”号( 1 995年完工)为首制船,共建造了2 0余艘双壳VLCC。特别是从1 998年完工的“TAKACHIHO II”开始,其系列船的载重吨从2 8万吨增加到30万吨,已有1 7艘船完工交船。但是,以往的VLCC包括上述系列船,从波斯湾运送原油到日本,途经马六甲海峡,装载30万吨时的吃水超出了能航行的限制,为此,都绕道走L ONBOOK等吃水较深的海峡,需额外花费航行天数和燃油消耗。因而希望建造马六甲海峡吃水下能达到更多载重量的“马六甲型VLCC”的呼声增加,加上近年来港口规则限制的放宽,同以前比,进港时可装载更多原油的港口增加了,这样要求建造满足进港限制吃水下能装载更多原油的VL CC的呼声也提高了。MHIMU为响应客户此项要求,进行了深入开发研究,以VL CC建造实绩为基础,开发了能通过马六甲海峡的浅吃水型最大型载重量的“马六甲最大型型VL CC”。本文重点介绍超肥大型船的开发研究及防振设计技术的发展。2 通过马六甲海峡的最大型VLCC的概要本船设计假定的设计条件中,主要的设计项目如下:( 1 ... 相似文献
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