Study on Flow Field Around Vertical Breakwater Under Different Overtopping Conditions Based on Numerical Simulation

A numerical wave flume is constructed based on the Reynolds Averaged Navier-Stokes (RANS) equations with turbulence closure by a modified k-ε model to study the viscous interactions of waves with vertical breakwaters for different overtopping cases. The governing equations,the turbulence model,boundary conditions,and solution method for the numerical wave flume are introduced briefly. The reliability of the numerical wave flume is examined by comparing the numerical results with the experimental measurement...     

Mosaic desert pavement influences water infiltration and vegetation distribution on fluvial fan surfaces

Desert pavements (DPs) are critical for maintaining ecological stability and promoting near-surface hydrological cycling in arid regions. However, few studies have focused on eco-hydrological processes of DPs in the ecological systems of fluvial fans. Although DP surfaces appear to be barren and flat, we found that the surfaces are characterized by surface mosaic patterns of desert pavement (mosaic DP) and bare ground (mosaic BG). We investigated the effects of mosaic DP on water infiltration and vegetation distribution at six sites in fluvial fans (one on a hillside and five within the sectors of fans) along a southwest belt transect in northern Linze County, in the central Hexi Corridor (China). We found significant differences in mosaic DP between the hillside and sector sites in terms of pavement thickness and vesicular horizon thickness (Av thickness), particle composition, and bulk density, although significant differences were absent for mass soil water content, gravel coverage, and surface gravel size. The mosaic DP inhibited water infiltration by the pavement layer, where the sorptivity (S), initial infiltration rate (i_int), steady-state infiltration rate (i_sat) and infiltration time (T) averaged 1.19 cm/min^-0.5, 0.64 cm/min, 0.13 cm/min and 12.76 min, respectively. Where the pavement layer was scalped, the S, i_int, and i_sat increased by 0.27 cm/min^-0.5, 0.52 cm/min, and 0.40 cm/min, respectively, and the T reduced by 7.42 min. Water infiltration was mainly controlled by the pavement layer thickness (+), Av thickness (−), surface gravel coverage (−), fine earth (+) and fine gravel (−) in the pavement layer. The DP surfaces only had a sparse covering of shrubs, but an abundance of herbs. Few shrubs were present on the mosaic DP, but a greater number of shrubs and herbs grew on the mosaic BG. It can be concluded that DPs can maintain vegetation stability for different surface mosaic patterns. This study deepens our understanding of the eco-hydrological cycle of DP landscapes in arid regions.     

解梁与块单元衔接问题的新方法—单点约束法

本文通过单点约束方程,提出了解梁与块单元衔接问题的新方法。该方法比其它方法具有更大的灵活性和精确性,可推广到解其它不同维数的单元之间的衔接问题。     

The rule of release of carbon and heavy metals during weathering of rocks—A preliminary study

Release of carbon from rocks during their weathering is closely linked to its global circulation. The contents and chemical forms of inorganic carbon in limestone, mudstone, granite and basalt as well as in their weathering and pedogenic products have been examined. The results show that a geochemical process of carbon release from the rocks in the early stage of weathering is followed by its accumulation in the subsequent weathering products. The environmental geochemical behavior of some heavy metals related to inorganic carbon release and its accumulation are also studied in this paper. Experimental results show that the capacity of manganese to associate with carbonates increases with increasing concentrations of the latter, but the behavior of copper is opposite to that of manganese. Translated by Chen Mingzhong, Chengdu Library, Academia Sinica.     

The Analysis of Three Dimensional FEM for Interaction of the Gravity-arch Dam and Complex Ground at Geheyan,Qingjiang River

This paper introduces the analysis of three dimensional finite element method for the gravity-arch dam building on the complex ground. The foundation rock of dip and strain-slip, three faults, two weak intercalations and etc. arc considered in this calculation model. Water static pressure, gravity of dam, uplift, temperature stress and so on are computed, including three dimensional osmotic and temperature fields in the foundation. The range of calculation model is about 1400×900×600m2 . There are 1845 elements of all kinds, 3280 nodes in the network of finite element. The superlax iterative method is used to solve, and three dimensional perspective and software of after treatment are applied in analyses. The dimension of this computation is large, various results of treating complex problems are reasonable. The important basis has applied to designing unit. The computation is important practical significance for Geheyan Dam which is being built.     

滇中郝家河砂岩铜矿的地球化学及其成因意义

本文论术字滇中生代地层与矿区及春外围马头山组中铜的时空分布与迁移富集规律，揭示了矿床的沉积－后期叠加改造成因。成矿作用经历了同生沉积形成矿源层，后期叠加改造形成矿体的过程。后期改造中铜元素发生了大量迁移，矿质主要来自矿体之下伏紫色矿源层。     

内蒙古中部二叠纪碱性花岗岩及其地球动力学意义

西伯利亚板块南缘白音乌拉－东乌珠穆沁旗带的碱性花岗岩（Ｒｂ－Ｓｒ年龄２７６－２８６Ｍａ）生成于张性的构造环境，较西伯亚板块同中朝板块之间晚泥盆世－早石炭世的碰撞事件晚约６０Ｍａ，属于造山后的Ａ型花岗岩，可作为造山作用结束的标志。但在中朝板块北缘晚石炭世－二叠纪只发育钙碱性的晚造山花岗岩，直到三叠纪才出现碱性正长岩。相邻两大板块边缘之间岩浆活动的非对称性可能是受板块间面积和质量差别的制约。     

面向对象的空间数据采集

本文主要介绍在Turbo C++支撑下,用面向对象的方法,对地图的空间数据进行采集、分类、编辑、净化。该系统利用C++中面向对象的概念及类的继承与地图数据的层次关系相吻合的特点,使得数据的输出能满足更多的要求,并且针对地图数据量大的特点,引入了多态和动态覆盖相结合的方法,以满足内存和速度两方面的要求。     

一种新的水面蒸发计算方法

本文应用相似理论,提出一个考虑自由对流和强迫对流相结合的水面蒸发模式,并用实测资料对蒸发模式作了检验。     

铅在灰钙土土壤—植物系统与环境中的迁移和环境容量

本文通过作物盆栽试验、区域调查、农田径流和淋溶试验以及土壤生化活性和微生物试验,研究了铅在土壤、植物、水体中的迁移和累积,并通过迁移模式的计算得出了铅的土壤临界浓度和环境容量。