论《格尔尼卡》中的现代元素

毕加索的《格尔尼卡》是20世纪最伟大的艺术作品之一。这件具有大众意义的作品展现出绘画艺术与现代社会、思想和科技等相关领域的互动精神,从中可领略到《格尔尼卡》跨越绘画艺术而成为祈望人类永久和平的标志性的公共艺术作品之缘由。几何图形概念、摄影技术等作为现代元素对于《格尔尼卡》的视觉建构和意义的生成有着不可忽略的重要作用。     

先秦时代黄河流域洪灾与农田环境治理

先秦时代,黄河流域频发的洪水恶化了农业生产的环境,严重的内涝和土地的盐卤化影响了平原农业的发展。为促进农业生产环境的改善,田间沟洫系统的发展及引浑淤灌等土壤改良的措施成为当时农田生产环境治理的基本内容。     

关角隧道大变形处理技术

关角隧道全长32.645 km,为目前国内在建的最长的单线铁路隧道。隧道通过区岩性极其复杂,沉积岩、岩浆岩、变质岩三大岩类均有出露,断裂构造极为发育,通过大小不等断层共17条,其中二郎洞断层束长达2 355 m,且具有一定的高地应力。受复杂地质的影响,关角隧道施工中发生了不同程度的大变形,最大变形达到了505 mm,现场对发生变形段采取了横撑、长锚杆、径向注浆、二次支护等措施进行加强,对未开段采取了加强初期支护、双层初期支护、调整初期支护曲率等措施来抑制变形并取得了成功。     

三点渐进式无模成形分析与数值模拟

渐进成形是一种金属板材快速无模成形方法。工具头挤压板材产生连续的局部变形,通过累积局部变形以达到整体成形。然而每一局部变形必然影响整体变形,所以对局部变形的控制就成为成形精度的关键。文章提出一种3点渐进式无模成形方法,可以很好的控制的局部变形。通过LS-DYNA模拟整个成形过程,并通过分析节点在成形过程中的位移变化,可以看出此方法对局部变形的控制效果,提高了成形精度。     

铁路隧道下穿施工引起既有铁路线路变形规律研究

近年来,随着我国铁路交通的大规模建设,新建铁路以隧道的方式下穿既有铁路越来越多的出现且在大量的工程当中且影响越来越严重。结合京石高铁下穿既有石德铁路工程,对下穿隧道暗挖段进行了数值模拟计算,分析研究了隧道下穿施工时对既有铁路路基沉降、轨道沉降、轨道水平偏差及轨向偏差的变形规律,得出了隧道下穿施工对既有铁路线路的影响,对工程的设计和施工具有一定的指导意义。     

气门落座有限元分析方法的研究

本文分析了气门动态落座时作用载荷分布处理方式及约束条件的确定对气门落座时变形及应力有限元分析计算精度的影响,提出了合理的载荷分布及约束条件确定方法。     

Norm-preserving constraint in the Fisher–Rao registration and its application in signal estimation

Registration of temporal observations is a fundamental problem in functional data analysis. Various frameworks have been developed over the past two decades where registrations are conducted based on optimal time warping between functions. Comparison of functions solely based on time warping, however, may have limited application, in particular when certain constraints are desired in the registration. In this paper, we study registration with norm-preserving constraint. A closely related problem is on signal estimation, where the goal is to estimate the ground-truth template given random observations with both compositional and additive noises. We propose to adopt the Fisher–Rao framework to compute the underlying template, and mathematically prove that such framework leads to a consistent estimator. We then illustrate the constrained Fisher–Rao registration using simulations as well as two real data sets. It is found that the constrained method is robust with respect to additive noise and has superior alignment and classification performance to conventional, unconstrained registration methods.     

论汉魏六朝音乐赋的新变

汉魏六朝音乐赋中乐器赋占绝大多数,始于两汉,盛于两晋,在发展过程中题材不断拓展,呈现出骚体趋于俳体,骈偶化增强的趋势。其发展兴盛、题材拓展、体制变化的过程与当时的社会生活内容的拓展、人们的喜好和文学体制的变化息息相关,成为了解和考证当时社会生活的一面镜子。     

Euler(p,q) Processes and Their Application to Non Stationary Time Series with Time Varying Frequencies

We introduce Euler(p, q) processes as an extension of the Euler(p) processes for purposes of obtaining more parsimonious models for non stationary processes whose periodic behavior changes approximately linearly in time. The discrete Euler(p, q) models are a class of multiplicative stationary (M-stationary) processes and basic properties are derived. The relationship between continuous and discrete mixed Euler processes is shown. Fundamental to the theory and application of Euler(p, q) processes is a dual relationship between discrete Euler(p, q) processes and ARMA processes, which is established. The usefulness of Euler(p, q) processes is examined by comparing spectral estimation with that obtained by existing methods using both simulated and real data.     

大断面黄土隧道洞口段施工数值模拟分析

依托平阳高速某黄土公路隧道，采用三维数值模型对隧道洞口段不同施工工法施工过程中围岩变形和支护结构的受力规律进行研究。研究结果表明：(1)各工法下施工阶段最不利状态：台阶法为上台阶施工，CRD法为先行洞上导坑施工，双侧壁导坑法为中上导坑施工，当进行到上述工序时应加强监控量测，开挖后及时施作初期支护。(2)黄土隧道洞口段优先采用双侧壁导坑工法以防止围岩产生过大变形。