长江三峡花岗岩坡面林地土管特性及其对管流的影响

相互连通具有一定通透性的土壤大空隙称为大孔隙,亦可称其为土管。根据土管成因不同将其分为四种类型,即土壤动物流动导致的土管、植物根系形成的土管、土壤裂隙形成的土管和土壤水分运动形成的土管。在长江三峡花岗岩地区至少存在两种成因的土管,即植物死亡根系形成的（生物性）土管和由土壤裂隙形成的（地质性0土管。由降雨导致水分在土壤大孔隙中的运动过程称为管流,管流是优先流的主要形式之一。管流的产生对于降雨而言具有一定的滞后性（管流开始出现一般较开始降雨时间推迟3－4小时）,管流的产生与降雨强度、降雨量和土壤水力特性等要素有关,相同条件下管流流量和降雨强度及降雨量呈正相关,管流特性不仅与土管的成因有关,而且与土管在土壤剖面的位置也有一定关系。由于土管内部粗糙程度和分枝合流情况不同,土壤前期降雨量、本次降雨强度影响也造成管流的水文过程产生差别。     

CHANNEL CHANGES DOWNSTREAM FROM A DAM1

ABSTRACT: A flood-control dam was completed during 1979 on Bear Creek, a small tributary stream to the South Platte River in the Denver, Colorado, area. Before and after dam closure, repetitive surveys between 1977 and 1992 at five cross sections downstream of the dam documented changes in channel morphology. During this 15-year period, channel width increased slightly, but channel depth increased by more than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand in the pools and fine gravel on the rime to a median coarse gravel throughout the reach. The most striking visual change was from a sparse growth of streamside grasses to a dense growth of riparian woody vegetation.     

泥石流突发性流动和剪切稀化的相关研究：以云南蒋家沟泥石流为例

泥石流突发性流动与泥石流剪切稀化特性相关。在低速率时（γ＝２．５ｓ－１），流体粘度稀化速率（Ｂ１）比高速率时大２个数量级，并与浓度（ＣＶ）呈正相关。当γ＝７ｓ－１时，流体粘度（ηｓ）与线性浓度（λ）对剪切时间（ｔ）依赖性，表现为较强烈的剪切稀化特性，其表达式为ηｓ（ｔ）＝４２５８［（λ－１＋１）－３×ＣＶｍ］４．８５［（（λ－１＋１）－３×ＣＶｍ）１．６５－０．３７ｔ＋１］。经显著性差异检验，当α＝０．０１水平时，该项试验达极显著水平（α＝６．４８３７＊＊），９５％置信区间达０．７８１６＜ρ＜０．９５３３。故高浓度泥石流呈强烈触变性、层流和层动流流态     

板内火山喷发机制的研究

本文从地幔对流的观点出发，结合物理学中的涡旋定律及热爆炸理论，指出地幔对流涡旋中心摩擦生热导致的热爆炸导致氚，氚的热核反应炸裂涡旋中心上部地壳形成板内火山喷发，并利用美国Ｇｏｄｄａｒｄ宇航中心的卫星重力扰动位系数，反演了五大连火山地区的地幔对流图像，指出五大连池火山地区存在－地幔涡旋。     

IMPROVEMENT OF LEACHATE PREDICTION THROUGH MUNICIPAL SOLID WASTE LAYERS1

ABSTRACT: Existing leachate prediction models over- or underestimate leachate generation by up to three orders of magnitude. Practical experiments show that channeled flow in waste leads to rapid discharge of large leachate volumes and heterogeneous moisture distributions. In order to more accurately predict leachate generation, leachate models must be improved. To predict moisture movement through waste, the one-domain water balance model HELP, and two-domain PREFLO, are tested. Experimental waste and leachate flow values are compared with model predictions. When calibrated with experimental parameters, the HELP model yields reasonable predictions of cumulative leachate flow and PREFLO provides estimates of breakthrough time. In the short term, field capacity has to be reduced to 0.12 and effective storage and hydraulic conductivity of the waste must be increased to 0.2 and 2.2 cm/s respectively. In the long term, a new modeling approach must be developed to adequately describe the moisture movement mechanisms.     

RECYCLING INPUT DATA DURING ANALYTIC ELEMENT MODELING NEAR INDIANAPOLIS,INDIANA1

ABSTRACT: Overlapping and adjacent ground water investigations are common in areas where aquifers are threatened by industrial development. In the Indianapolis area in Marion County, Indiana, a patchwork of ground water flow models have been used during the past 20 years to evaluate ground water resources and to determine the effects of local contamination. In every case these ground water models were constructed from scratch. Site specific finite difference grids or finite element meshes inhibit the direct reuse of input data when the area of interest shifts. Because the aquifer is not discretized into a grid or mesh with analytic element models, there are unique opportunities for direct reuse of model input data. In two applications of this principle we illustrate how the newly emerging analytic element method allows a fairly straightforward reuse of model input data from previous models in the same general area. In analytic element models of Central Indiana, streams and their tributaries are represented in different resolutions. Input data items of several modeling studies are stored and cataloged on disk in such a manner that they can be selectively retrieved by a data management program PREPRO. In this manner, a new ground water model can be set up quickly with input data which have been previously defined and tested during model calibration.     

火灾现象的数值模拟及其应用

本文讨论了模拟火灾现象的数值方法及其应用。着重研究了火焰发热、空气流动和烟尘传播的数学模型，讨论了紊流模型中浮力项的处理和边界条件的简化，并介绍了这一课题的研究现状和发展方向。     

FLOW DURATION CURVES II: A REVIEW OF APPLICATIONS IN WATER RESOURCES PLANNING1

ABSTRACT: A streamflow duration curve illustrates the relationship between the frequency and magnitude of streamflow. Flow duration curves have a long history in the field of water-resource engineering and have been used to solve problems in water-quality management, hydropower, instream flow methodologies, water-use planning, flood control, and river and reservoir sedimentation, and for scientific comparisons of streamflow characteristics across watersheds. This paper reviews traditional applications and provides extensions to some new applications, including water allocation, wasteload allocation, river and wetland inundation mapping, and the economic selection of a water-resource project.     

A VOLUME BALANCE SOLUTION FOR WATER FLOW OVER FLAT SOIL SURFACES1

ABSTRACT: This paper presents the development of a mathematical model to compute the advance of water flowing over flat soil surfaces. The solution is of interest to the design and management of irrigation systems, and the model can also be applied to overland flow problems. The hydraulics of water flow during the advance phase is simulated by the Lewis-Milne integral equation. The general solution to this equation is obtained by using the Laplace transform theory. A particular solution was developed, based on series expansions, that uses the modified Kostiakov equation to predict infiltration. The solution is given by a double infinite series that has terms of alternate sign. Results from this model show satisfactory agreement when compared with field data collected by the author.     

水射流技术在牙轮钻头中的应用与研究进展

介绍了喷射钻井井底流场特性、喷嘴射流破岩机理、脉冲射流喷嘴、新型水力流道钻头的研究与应用情况，以及水射流技术在石油钻井用钻头上的应用前景。