Effect of structure and texture on infiltration flow pattern during flood irrigation

Understanding the flow pattern of water and solute in subsurface soils is critically important in the fields of agricultural and environmental sciences. Dye tracer tests using a flood irrigation of Brilliant Blue FCF solution (5 g l^-1) and excavation method was performed to investigate the effect of texture and structure on the infiltration pattern at three different field soils developed from granite (GR), gneiss (GN) and limestone (LS). The GR soil showed a homogeneous matrix flow in the surface soil with weak, medium granular structure and a macropore flow along pegmatitic vein and plant root in C horizon. The surface horizon (A1) of GN soil with moderate, medium granular structure and many fine roots had matrix flow. The fingering occurred at the interfaces of sandy loam A horizon and loamy sand C horizon in GR soil and loam A1 horizon and sandy loam A2 horizon in GN soil. The LS soil with strong, coarse prismatic structure and the finest texture showed a macropore flow along cracks and had the deepest penetration of the dye tracer. The macropore (crack and vein), layer interface and plant root induced the preferential flow in the studied soils.     

结构状态智能模拟技术研究

提出了一套结构状态智能模拟技术,融结构分析方法和计算机技术为一体,主要将信息处理智能方法应用到结构状态的模拟及可视化中,并结合了混合编程技术、可视化技术、基于XML的接口技术、软构件技术及工程数据库技术等,提出了智能可视化的概念。研究了两种基于灰色系统的改进的小样本数据可视化预测模型,并以基于XML可视化接口为基础,应用智能模拟技术,建立结构状态智能模拟环境的基本骨架。     

地震作用下可分离接触面研究综述

可分离接触面在地震中起重要作用，并且是一个尚未充分研究的领域。叙述了目前国内外关于可分离接触面的研究方法(线性化方法、数值分析法、接触面层法、修正法)及研究现状，指出，应不断完善无分离接触面的研究。     

硫酸盐渍土在不同降温速率下的盐胀规律

降温速率对硫酸盐渍土的盐胀率有显著影响。随降温速率的减小，各种含盐量、密实度的硫酸渍土的盐胀率以幂函数增长，其通式为ｙ＝ＡＶＴ＾－Ｂ，但其增长规律彼此又有显著差别，主要表现在Ａ、Ｂ参数的变化上，在试验范围内，Ａ、Ｂ值随含盐量的增加而增加，随密度的增大而减小。     

Patterns of Winter Desiccation in Krummholz Forms of Abies Lasiocarpa at Treeline Sites in Glacier National Park, Montana, USA

Winter desiccation-induced foliage loss at high-elevation locations is an important determinant of positive carbon balance for trees and thus influences the location of the alpine treeline ecotone. In this study, data are presented that describe the amount of winter desiccation incurred by krummholz growth forms of subalpine fir ( Abies lasiocarpa (Hook) Nutt.) at treeline locations in Glacier National Park, Montana, USA, for the winter of 1998/1999. An average 8.68% of the krummholz canopy was lost due to desiccation.
Winter desiccation is not predictable based on any single environmental variable. When outliers are removed, winter desiccation shows a strong correlation with elevation ( r = 0.97). Patch level winter desiccation amounts are, however, highly predictable from elevation, slope, aspect and topographic context when considered together. In general, injury increases with elevation and on more southwesterly facing hillslopes. High slopes and sheltered locations decrease winter desiccation.
Within patches, most winter desiccation is located at the windward edge of the patch. This trend may be modified by the presence of leaders above the mean canopy surface of the krummholz patch, or by local microtopographic features such as dead branches or the proximity of large rocks.
The winter of 1998/1999 was a high winter desiccation year compared to the two previous winters. The winter of 1998/1999 had high snowfall, and meltout did not occur until later than the previous two winters. The extended period of snow cover is hypothesized to be one of the causes of the increased winter desiccation for the 1998/1999 winter.     

A fuzzy information processing system of seismic data

We have developed a workstation-assisted information processing system. The system has three major functions: information retrieval from seismic data, detection of earthquake precursors, and graphical display of relevant results. Fuzziness is inevitably involved in these functions, an adequate treatment of which is vital. The system accepts instructions given by a successive choice of words in hierarchal structure, which is followed by a tune-up of the corresponding membership function. The degrees of fuzziness in the outputs are recognized visually, for example, by coloring. This contrivance together with dynamic data exchange among the above functions facilitates the operation of the system. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 399–406, 1993. This study is partly supported by a project “Fuzzy systems and their applications to human and natural sciences” of Science and Technology Agency.     

深部大尺度单一密度界面重力异常迭代反演

对于深部大尺度单一密度界面的重力异常反演,需顾及球形观测面和重力铅垂线变化的影响。为此,本文通过球谐展开,得到重力异常的级数展开式,并推导出积分形式的反演迭代解。该迭代方法要求设法分离出单一密度界面的重力异常,已知界面上、下层的密度差和尽可能多的深度控制点。模型和实例显示其效果良好,可用于莫霍界面、岩石层底界面等深部密度界面重力异常的反演。     

孔隙压岩石三轴摩擦实验装置

孔隙压岩石三轴摩擦实验装置是研究孔隙压对岩石滑动面摩擦性状影响的专用设备.该设备包括孔隙压岩石三轴实验装置和岩石摩擦装置两部分.摩擦装置由上、下压头,密封套筒和具有内部滑动块体的岩石样品组成.滑动面宽20×20mm、高40mm 的长方体,滑动面宽20mm、高30mm.最大孔隙压P_(max)=100MPa,最大位移L_(max)=10mm.应用该装置将三轴条件下样品之间的斜向摩擦滑动变为轴向滑动.滑动面上的法向压力σ_n=σ_3,即σ_n 变为与轴压无关的独立变量.     

《中国冰雪冻土图》(1:400万)的编制

中国冰雪冻土图是双全张挂图,供读者了解我国冰川、季节积雪、海河湖冰、冻土及冷生现象等自然现象的分布特征、资源现状以及与人类社会活动的关系。上述自然现象的发生与变化是相互联系的,它们之间的关系又是错综复杂的。本图的设计和制图综合考虑到以寒色为主,按冰川、积雪和冻土进行分类分级综合,冷生现象设计14种象形符号表示大致分布位置。     

费氏台法岩组分析中数据的计算机采集和处理系统

本系统是显微组构要素的费氏台N.H.I三轴测定系统。它由三路角度传感器,PC-1500计算机及其费氏台数据采集装置组成。系统可完成对多种线、面要素的每一粒(次)测定过程的自动数据采集、实时成图处理。采集精度高(角度偏差≤0.5°,无累积偏差),成图精度高,速度快,工作适应性强,用户介入性好,系统性能稳定,使用方便,软件适应范围宽,是一种易于普及的岩组测定数据采集及处理系统。