浅谈基于随机模型的隧道施工引起地面沉降的小波分析

目前预测隧道施工引起的地面随时间变化的沉降过程的方法有一定的局限性，这种局限性是由于测量误差的存在而引起的。在这项研究中，研究的方法是用数据建立一个随机模型的时间序列，而测量误差被作为是一个按正态分布的随机序列。另外，按正态性检验和方差分析的方法，被用来验证沉降数据过滤部分的特性与测量数据的误差是否是一致的。这样，当采用离散小波变换时，就可以确定小波基及分解水平的最佳选择。利用一个工程实例去验证了这种假设，并证明了这种方法的可行性。     

人性在信仰与现实中升华

《少年派的奇幻漂流》是一部关于少年派在海上漂流生存的富有传奇色彩而隐藏深意的影片。这部电影的叙述风格和艺术效果与美国作家福克纳的短篇小说《纪念爱米丽的一朵玫瑰花》十分相似,都是直到最后一刻才从作者精心构造的迷宫里走了出来,真相恍然大悟,却又意犹未尽。该影片不仅仅为我们展现了梦幻的视觉效果,而且对文本本身表现出如梦般的精神内涵。从精神分析理论透过弗洛伊德等人对梦的形成及与现实的关系等层面看,影片实质上表达了一场信仰与现实的对抗。     

The Cost of Nutrient Reduction: A Case Study of Chesapeake Bay

Over $3.5 billion were spent toward nutrient controls in the Chesapeake Bay watershed between 1985 and 1996. These expenditures were based on cost-shares between federal, state, local, and private sources and should be considered conservative. A comparison of point and nonpoint nutrient control expenditures in the Bay basin showed that about 50% of the funds were directed toward agricultural best management practices and 45% were allocated for point source nutrient reductions and combined sewer overflows (20% and 25%, respectively). The remainder was spent on various other estuarine-targeted programs. Maryland was responsible for 79% of the total expenditures, 16% was expended by Virginia, and the remainder was attributable to the District of Columbia and Pennsylvania (4% and 1%, respectively). The most costly basin was the Patuxent (over $125 per kilogram of total nitrogen removed) and the least costly was the Eastern Shore of Virginia, where the cost was just under $21 per kilogram of nitrogen removed. For the control practices examined, the analysis found that nutrient management was the least costly. Animal waste control and low tillage were the second and third most economical nutrient management strategies. Significant reductions were achieved from point sources for both total nitrogen (16%) and total phosphorus (53%) by 1996. Virtually all of the large reduction in point source phosphorus was a result of the phosphorus detergent ban implemented basinwide in the late 1980s. Nonpoint source nutrient reductions were more modest. An approximate 12% reduction in phosphorus was accompanied by an 8% reduction in total nitrogen loadings. Despite these nutrient reductions, no significant improvements in bottom-dissolved oxygen levels were detected along the Bay mainstem during the warmer months, and the mouth of Chesapeake Bay showed marginally significant degradation during the 11-year period. It was determined that dissolved oxygen conditions were influenced more by nitrogen than phosphorus reductions and that nutrient controls aimed at the mid-Bay region had the greatest potential for improving low dissolved oxygen conditions in the Bay's bottom waters.     

基于SD模型的城市群—交通影响机理研究

研究了城市群交通影响预景分析及城市群交通需求分析理论,对基于系统动力学(SD)的交通影响预景分析方法、城市群交通需求分析方法进行了较为深入的探讨,建立了交通影响预景分析模型和城市群交通需求分析模型体系。通过实例验证了所提方法的有效性。     

高墩大跨铁路桥梁动力特性分析

近年来,随着我国铁路桥梁的迅速发展,桥梁的跨度越来越大,桥墩越来越高,体系越来越柔。高桥墩体自重大、柔度大、阻尼小。本文以某大跨高墩连续刚构桥为计算模型,应用通用软件Midas/Civil建立了三维动力有限元模型,对该桥进行动力特性分析,得出该桥的前十阶振型。并就加弹性阻尼器对结构的动力影响进行分析,得出加弹性阻尼器能够改变结构的动力性能。     

双加坪滑坡成因及处治措施研究

以石棉县双加坪滑坡为例,在探明滑坡地质条件的基础上,分析了滑坡形成的原因;基于极限平衡理论折线形滑动面条分法进行稳定性分析。结果表明:在天然状态下,滑坡基本稳定,在持续降雨条件下,大部分不稳定或欠稳定;在地震力作用下为不稳定滑移状态。对此,提出了合理的处治措施。     

船用空压机典型故障的事故树分析

运用FTA（事故树定性分析）的定性方法，分析船用空压机典型故障问题的事故树模型，探讨船用空压机典型故障的预防途径，为船用空压机管理过程中的安全管理、安全评价以及事故分析提供参考。     

工程定额经济属性与运用辨析

根据定额的起源与发展，详细论述工程定额的经济属性、特性及用途。通过进一步分析和探讨，阐述在当前深化经济体制改革的形势下，如何在工程建设的前期、工程招投标期、工程实施期科学合理地运用工程定额，并根据市场经济原则把握采用的定额水平。为适应新的经济环境，从经济和技术层面，提出工程定额改革与发展的思路。以此来提升施工和管理水平。     

信号楼电气火灾原因分析

在调查研究和总结实践的基础上,从设计角度阐述了铁路信号楼电气火灾发生的主要原因。     

电气化铁道接触网用棒形瓷绝缘子抗弯受力分析

分析电气化铁道用棒形瓷绝缘子的受力状况，并通过试验进行验证。根据计算和试验结果，提出对TB／T2076《电气化铁道接触网用棒形瓷绝缘子》的修改建议。