Hierarchical Spatially Varying Coefficient Process Model

The spatially varying coefficient process model is a nonstationary approach to explaining spatial heterogen-eity by allowing coefficients to vary across space. In this article, we develop a methodology for generalizing this model to accommodate geographically hierarchical data. This article considers two-level hierarchical structures and allow for the coefficients of both low-level and high-level units to vary over space. We assume that the spatially varying low-level coefficients follow the multivariate Gaussian process, and the spatially varying high-level coefficients follow the multivariate simultaneous autoregressive model that we develop by extending the standard simultaneous autoregressive model to incorporate multivariate data. We apply the proposed model to transaction data of houses sold in 2014 in a part of the city of Los Angeles. The results show that the proposed model predicts housing prices and fits the data effectively.     

光面爆破在卡鲁玛尾水隧洞开挖中的改进与应用

在乌干达卡鲁玛尾水隧洞8#支洞Ⅲ类围岩开挖中,为了解决光面爆破施工中用的25mm细药卷短缺、绑扎光面爆破药串用的竹片无法买到等问题,采用了经过加工的32mm常规药卷,调整了光面爆破孔内装药结构和装药方法,并在选用常规周边光面爆破孔孔距条件下,适当减小光面爆破层厚度,将周边光面爆破孔密集系数提高到1.25~1.43。爆破实践表明:通过一系列改进,即便在只有最常见的32mm常规药卷和导爆索条件下,仍能取得良好的光面爆破效果。这一改进简化了光面爆破药串加工工序,减少了光面爆破层脱落需要克服的阻力,减轻了爆破对洞周被保留岩体的伤害。     

轴流涡轮与排气壳扩压段一维耦合设计研究

为探究轴流涡轮耦合排气壳扩压段的一维设计变量选取规律,提高排气壳扩压段的性能,参考现有NRCC叶栅导叶模型,采用自编程序,结合理论分析构建轴流涡轮与排气扩压段耦合的一维设计模型。详细分析耦合设计中影响扩压段的静压恢复系数以及总体性能的因素。研究结果表明：扩压段面积比、平均倾角、扩张角以及壁面摩擦系数等设计参数不仅影响扩压段的静压恢复系数,也影响涡轮的气动效率;本研究模型在面积比为3.5、平均倾角为30°、扩张角δ为5°时整体性能最优;涡轮出口气流的马赫数、叶顶泄漏流以及出口旋流对扩压段的性能有很大影响,出口半径比的增大会使得静压恢复系数降低,因此在耦合设计时应充分考虑涡轮以上参数的选择。     

基于流-热-固单向耦合计算的LNG船用蝶阀流动及结构改进设计

以超低温蝶阀为研究对象、LNG液化天然气（Liquefied Natural Gas,LNG）为流体工质,利用Solidworks软件对蝶板的结构尺寸进行参数化处理。基于计算流体力学数值模拟技术,利用Ansys软件对蝶阀开展流-热-固单向耦合计算分析,计算90°~10°不同蝶阀开度下蝶板的流量系数,及蝶阀开度10°下不同蝶板结构参数对蝶阀流通性能、蝶板位移及应力行为的影响。计算结果表明：减小蝶板厚度可以显著增强蝶阀的流通性能,降低蝶板所受最大应力;降低轴颈厚度对蝶阀流通性能提升效果较弱,但可以有效降低蝶板所受最大应力。     

不同地应力下的地下硐室动态特征分析

采用FLAC3D对地震动荷载作用下不同地应力状态的地下岩体硐室的动态特性进行了初步分析。分析结果表明,地震荷载作用下,硐室位移随地应力侧压系数的增加明显减小,地应力侧压系数λ<1时的硐室位移量值随侧压系数的变化幅度明显大于地应力侧压系数λ>1时的情况;当侧压系数λ<1,随剪切波入射角的变化,硐室测量点位移响应先增加后减小;而当侧压系数λ>1,随剪切波入射角的增加,硐室测点位移先减小后增加,同时随地应力侧压系数的增加有减小的趋势。     

Waves Past Porous Structures in a Two-layer Fluid

Havelock’s type of expansion theorems, for an integrable function having a single discontinuity point in the domain where it is defined, are utilized to derive analytical solutions for the radiation or scattering of oblique water waves by a fully extended porous barrier in both the cases of finite and infinite depths of water in two-layer fluid with constant densities. Also, complete analytical solutions are obtained for the boundary-value problems dealing with the generation or scattering of axi-symmetric water waves by a system of permeable and impermeable co-axial cylinders. Various results concerning the generation and reflection of the axisymmetric surface or interfacial waves are derived in terms of Bessel functions. The resonance conditions within the trapped region are obtained in various cases. Further, expansions for multipole-line-source oblique-wave potentials are derived for both the cases of finite and infinite depth depending on the existence of the source point in a two-layered fluid.     

应用锥形压边圈进行拉伸的探索研究

为探索高效能的拉伸,本文结合实际生产问题,提出了一种全新的压边模式,对其作出了详细的分析与研究,并得出了相关结论。     

基于ATR技术的有机聚合物二次电光系数的测量

二次电光效应是有机聚合物材料一种重要的电光特性,利用这种特性可以制备有机聚合物电光调制器等电光器件.有机聚合物材料的二次电光系数是衡量其二次电光效应的一个重要参数,其可以用一个6×6阶的张量来表示.利用该张量的对称特性、各个元素之间的已知关系以及折射率椭球公式,本文提出了一种基于衰减全反射(ATR)技术的测量有机聚合物二次电光系数的方法.在测量中,通过选用TM偏振光以及TE偏振光作为测量光束,可以分别获得二次电光系数张量中S11以及S12元素.利用已知关系,可以计算得到S44以及直流克尔系数.从而得到二电光系数张量中所有元素的值.     

微系统技术（连载六）─性能与测试

简要介绍了利用新型干涉仪测量微机械零件表面粗糙度的原理和方法，加载结构动摩擦系数测量，微系统器件残余应力分析和半导体器件表面电位测量。     

A computer program for internal conversion coefficients and particle parameters

Title of program: CATAR Catalogue number: ABGP Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: UNIVAC 1108; Installation: Sandoz A.G., Basel, Switzerland Operating system: EXEC 8 Programming language used: FORTRAN IV High speed store required: 26K words No. of bits in a word: 36 Overlay structure: None Number of magnetic tapes required: None Other peripherals used: Card reader, line printer Number of cards in combined program and test deck: 3136 Card punching code: BCD