北极海冰运移和消退的数值模拟(英)

A sea ice model which contains Hibler's (1979, 1980) dynamics and Parkinson & Washington's (1979) thermodynamics is used to simulate the seasonal cycle of sea ice motion, thickness,compactness and growth rate in the Arctic Ocean under mean annual climatological forcing. Furthermore, it is used to investigate the air-sea heat flux and mean annual heat state over the entire Arctic Ocean.     

Comparison of requirements for modeling snowdrift in the case of outdoor and wind tunnel experiments

This paper reports on modeling of drifting snow phenomena. It comprises a review of the conditions for a correct simulation of snowdrifting in wind-tunnel or outdoor comparing requirements proposed by four scientists (Kind, 1975, 1985; Iversen, 1979, 1980, 1981, 1982, 1984; Anno, 1984, Tabler, 1980). Comparisons of these requirements were based on full-scale measurements, wind tunnel simulation, outdoor modeling with snow or sand.     

清代方测雨器、方蒸发器由来考

本文前半部介绍我国清乾隆年间戴源所记方测雨器、方蒸发器的构造和作用,并对比介绍欧美方测雨器及方蒸发器的沿革。后半部主要探讨这些仪器外形方圆变化的原因。并对戴源仪器本身及《测圆图解》进行分析,进而证明这种仪器并非我国自创,却系耶稣会传教士由巴黎传入中国。但在我国气象仪器史中有着重要意义。     

围岩弱化原理及其分析

本文根据岩体改造中的弱化原理及地下洞室围岩变形失稳机理,深入研究了围岩弱化法。对围岩弱化原理进行了定性分析,用边界单元方法和相似材料模型实验研究了切缝这种围岩弱化技术对硬岩和软岩洞室稳定维护的效果。     

岩巷掘进中的瓦斯灾害特征及对策初探

煤矿生产中的瓦斯灾害,以往是指煤层掘进或回采工作面的瓦斯突出或涌出,以及煤系地层中砂岩掘进时的二氧化碳突出。而非煤系地层岩巷掘进中的煤岩突出及大量瓦斯的快速涌出,则是随着煤矿生产的发展而新出现的一大灾害,不容忽视。井巷掘进中,瓦斯不断涌出,其型式分缓变、突变、突增渐缓三种。以瓦斯地质的观点,对松藻矿务局岩巷掘进中瓦斯灾害特征及预防对策进行了讨论。     

新疆托里县老风口风雪灾害及其生物治理

本文根据老风口林场和公路雪害防治实验站资料，综合分析风区的自然地理条件，风区植树造林防治风雪灾害的成功经验和失败教训，并总结出一套行之有效的生物治理措施，即营造多带小网格蜂窝结构的防网阻雪林网。其效果明显，可促进生态环境良性循环，改善了公路冬季交通条件。     

软弱围岩隧洞施工性态的力学模拟与分析

本文着重对软弱围岩隧洞施工中的力学性态进行了计算机模拟和分析。文中除提出了考虑隧洞开挖面时空效应的三维分析模型外，还计入岩体流变时效，进行了弹－粘塑性数值计算。其中，研讨了开挖面推进过程中洞室围岩与错喷支护的相互作用以及设置整筑式二次内衬的影响。用所建议的力学模型和编制的程序软件，结合某实际工程，分别就洞室上下台阶法分部开挖、全断面法一次开挖和侧壁导坑法扩大开挖等三种最常见的隧洞施工作业方式进行了模拟分析，并将计算成果与现场实测数据作了比较验证。     

水电站进水口快速闸门水力学分析

主要分析水电站进水口快速闸门在动水关闭过程中流量、临界开度和闸门受水流作用力(闸顶水压力、闸底水压力和闸门水平压力)等问题。根据模型试验所观测的水力现象和非恒定流计算理沦,提出了计算电站闸门、引水管道的水力参数(流量、水头和通气孔水位等)的数学模型。实例计算结果和模型试验结果基本吻合。     

流-风-波共存下溢油漂移的实验室模拟

在实验室中测定了流速0～34m·s－1，风速0～13m·s－1、正弦波高0～0．13m范围内，流、风、波单独存在及共存时，胜利油田原油在水面上的漂移速度，建立了包括流速和风速矢量及波高三个参数的胜利油田原油漂移速度的经验公式。     

A practical method to estimate crack openings in concrete structures

Numerical modelling of concrete cracking requires robust models able to describe opening and propagation of cracks. Structural concrete codes provide practical relations to describe crack openings. However, these empirical methods were developed for specific structures and cannot be used for general applications. Here, a continuous modelling approach based on damage mechanics is used to compute crack openings in a tie‐beam concrete structure. We propose a post‐processing method to extract crack openings from a continuum damage finite element computation. This method can be applied to all continuum damage/plasticity models. The tie‐beam concrete is characterized by a weak stress gradient; this aspect complicates predictions of crack positions and number. A stochastic method is used to take into account the spatial variability in concrete properties and create a spatially correlated random property field. Copyright © 2010 John Wiley & Sons, Ltd.