划水板流体动力特征的风洞实验研究

本文介绍了自行研制的三种划水板和国外两种划水板及其在风洞内进行的测力实验,以了解分析其不同的流体动力特征;对板面开孔与无孔吹风测力、板面有或无稳流板条及板条分布的测试结果,为新型划水板的设计提供了理论依据。研究发现,螺旋曲面扭转结构的自制板对运动员手掌最佳对水倾斜角有诱导修正作用,能帮助运动员建立良好的技术,提高“水感”,获得理想的划水效果。实验结果表明以上观点是可以肯定的。     

Valuation struggles over pricing – determining the worth of wind power

Public policies such as feed-in tariffs have been widely introduced to stimulate the development of renewable energies, and sustain a decarbonisation of the electricity sector. Proponents argue that these governance instruments safeguard public goods such as the climate – yet they are accused of creating political markets, and political prices, here understood as market distortion. This paper studies the ‘politics’ of pricing by following the adoption of the first feed-in tariff in France. Pricing as a way of achieving non-economic ends, such as climate mitigation, brings the values of several public goods into play, all the while prompting a translation of these values into a single price. Following the struggles over the pricing of wind power in the early 2000s, the study illustrates that rather than a pollution of the market sphere by that of politics, a politics of pricing can be observed in four distinct struggles: namely the framing of the public interest; valuation as the articulation of the future; the possible agencies of governance; and role of valuation methods and calculations.     

Study on effect of segments erection tolerance and wedge-shaped segment on segment ring in shield tunnel

INTRODUCTION Shield tunnel method has become the most pre- ferred method in city tunnel construction because of its excellent attributes: little effect on surrounding environment, fast and safe construction, outstanding performance in earthquake resistance, etc. (Zhang et al., 2004). In different shield tunnels, the arrangement and number of segments are different, but the whole assembling process is generally the same. The as- sembling process begins with A2P, then A1P, A3P, BP, CP, …     

龙宫水溶洞的成因分析

文章分析了龙宫水溶洞的形成机制,认为龙宫水溶洞是在地层地貌基础、水动力条件和断裂构造等因素的影响下形成的一个地下伏流系统。在新构造运动的影响下,喀斯特作用的向深性不断增强,水溶洞的局部顶板崩塌,使完整的伏流系统分解为五段地下水溶洞,称为"五进龙宫"。龙宫的龙门瀑布与黄果树瀑布在形成机理上有一定的相似性。     

对土地的依恋与渴望永远不会随风而去

《飘》是在中国最受欢迎的美国小说之一。自1940年中文版首次问世以来,一直受到广大中国读者的青睐,并享有很高的声望。小说对主人公进行的细腻刻画,从一个侧面反映了人类对其赖以生存的土地的依恋与渴望。     

人生失路行将何之——阮籍《咏怀诗》八十与屈原《悲回风》之比较

阮籍《咏怀诗》第八十首和《悲回风》一样,是诗人的绝命诗。其从诗歌营造的肃杀悲凉的意境氛围、诗人对时间意识的自觉和生命价值的探寻及卓而不群、风神潇洒的“佳人”形象三个方面袭取屈原《悲回风》旨意,表达诗人人生失路、不知行将何之的惶惧和对个体生命价值的重新审视。     

关于泄洪洞水力设计中空蚀问题的探讨

首先介绍了空蚀破坏的原理以及发生空蚀破坏的条件，并分析了龙抬头式泄洪洞发生空蚀破坏的原因和易发生空蚀破坏的部位。最后，结合工程实例的实验结果，说明了发生空蚀破坏的主要原因是不平整度以及体型的不合理。     

公路隧道洞口段地震动力分析

根据以往的受震破坏经验,在公路隧道的高烈度地震带,地下工程可能会遭受严重震害,尤其洞口段为抗震薄弱区,本文采用FLAC3D软件,从土—结构相互作用模型出发,运用数值分析方法对隧道洞口段进行了三维弹性和弹塑性分析,得出了相应结论,并对结果进行分析,指出隧道抗减震设计中应注意的事项,并提出相应解决措施。     

锚杆支护在沿空掘巷中的应用

本文介绍了采用高强度螺纹钢树脂锚杆支护技术在复合顶板沿空掘巷现场的使用及效果,与架棚支护比较,支护成本明显降低,巷道顶板支护实现了安全可靠。     

高速铁路超大断面隧道施工方法数值模拟研究

针对高速铁路软弱、浅埋超大断面隧道,采用双侧壁导坑法、三台阶七步法两种施工方法分别进行三维数值模拟和开挖方法的科学性进行对比分析,结果表明:在施作大管棚超前支护的前提下,三台阶七步法比较合理.研究结论为同类工程的设计和施工提供理论参考.