广东博贺澙湖潮滩的冲淤变化及其动力作用分析

基于遥感技术,对反映17 a来博贺澙湖的5景遥感影像定量反演潮滩水边线,在此基础上推算澙湖潮滩的沉积与冲刷速率,同时对引起潮滩变化的动力作用进行探讨,结果表明博贺澙湖的潮滩以淤展为主,其中处于开敞地段的澙湖潮滩出现冲刷,遮蔽岸段的澙湖潮滩淤积,控制澙湖潮滩变化的主要因子是包括圈围潮滩成盐田、虾池以及鱼塘等的人类活动.     

国外深水钢悬链线立管研究发展现状

介绍国外在新型深水立管系统--钢悬链线立管关键技术方面的研究发展现状,论述浮体一、二阶运动对钢悬链线立管疲劳寿命的影响、浮体升沉运动对钢悬链线立管触地点疲劳寿命的影响;钢悬链线立管与海底相互作用机制的实验研究及结果;钢悬链线立管涡致振动与疲劳的研究现状.并简要论述钢悬链线立管触地点问题的研究结论.     

Ancient and modern cold-climate aeolian sand deposition: A review

Although partly active aeolian sand sheets and dunes cover large areas in the zones of (dis)continuous permafrost, little precise information is available about the influence of cold-climate conditions on modern aeolian processes. This means that palaeoenvironmental reconstructions in the stabilised, mainly Late Pleistocene dune fields and cover sand regions in the ‘sand belts’ of the European Lowlands and the Northern Great Plains of the USA and Canada, are necessarily still based on ancient evidence. Cold-climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains, glacial outwash plains, till plains and lake shores. The common parabolic and transverse dune forms resemble those observed in temperate regions. Although a variety of periglacial features has been identified in Late Pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity. Specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces, the nature of annual sedimentation cycles and the processes by which strata were deposited and/or contorted. But surprisingly little is known about the role of vegetation in the process of sand accumulation. Dunes are most informative with respect to reconstructions of past wind regimes, which offer important data for verification of palaeoclimatic simulations.     

冀中拗陷古潜山油田水化学研究

冀中拗陷油气田87%的储量产于海相碳酸盐岩古潜山中,在油气生成、运移、集聚和散失的过程中地下水起了重要作用。本文根据50个试样的水化学分析资料,运用对应分析方法对冀中拗陷古潜山油田水进行了分类并初步探讨了水化学成分演化与油气藏形成的关系。     

Rayleigh 阻尼作用下斜拉桥扭转振动

在侧向风力或侧向水平地源力作用下,斜拉桥容易发生扭转振动。本文采用非线性Rayleigh阴尼,它能反映在低速振动时有激发而加速振动,至一定高速后又衰减的完整振动过程。对非线性的统辖方程及定解条件,先使之无量纲化,再按非线性项的系数这个小参数展开未知函数,得到线性化的各级近似方程。把待求函数展成梁轴坐标的Fourier级数,其系数为待定的时间函数,应用Fourier级数的正交性,得到求解未知时间函数的二阶常微分方程,完全类似单自由度质点在线性粘滞性阻尼作用下的统辖方程,其解为已知。     

台风成因与地壳运动关系初探

本文从台风和世界上大多数热带气旋的密集生成区与板块相互作用的地壳剧烈活动区相吻合这一现象出发,认为当今台风成因的研究之所以遇到困难的原因之一,就是忽略了剧烈的地壳运动所产生的热流通过海洋这一特殊水解质对其上方大气所产生的影响。     

Conservation laws of wave action and potential enstrophy for rossby waves in a stratified atmosphere

The purpose of this article is to discuss the evolution of wave energy, enstrophy and action for atmospheric Rossby waves in a variable mean flow. The presentation is theoretical, but does not represent original research; rather, it is pedagogic in nature. The work of a number of people has been drawn together into a unified account, with much of the algebra implicit in previous work made explicit here. The central results are that wave energy is conserved only when there are no spatial variations in the mean flow, and wave action is conserved even in the presence of such variations as long as they are not in the longitudinal direction. Finally, wave enstrophy is conserved in the presence of arbitrary (slow) mean flow variations.     

Wind erosion of blanket peat during a short period of surface desiccation (North Pennines,Northern England)

Strong winds are a characteristic feature of UK upland areas. Despite this, understanding of aeolian processes in upland environments of the UK is limited. This paper presents direct measurements and observations of blanket peat erosion by wind action during a two week period of desiccation in the North Pennines, Northern England. A circular configuration of mass flux sediment samplers was used to collect peat eroded by wind action from 16 cardinal compass directions. Meteorological conditions (wind speed, wind direction, precipitation and temperature) were recorded by an automatic weather station set up adjacent to the site. Surface desiccation led to peat crust erosion and dust deflation. During short (≤1 hour) periods of precipitation, wind‐driven rainfall also caused erosion. Typically, dust flux rates were up to two orders of magnitude lower than recorded during periods of sustained wet weather. Measurements demonstrate the hitherto unreported rapid switch in process regime between wind‐driven rainfall and dry blow deflation in blanket peat environments. Dry blow processes of blanket peat erosion may become more important in UK upland areas if climate change promotes more frequent surface desiccation. Copyright © 2006 John Wiley & Sons, Ltd.     

浅述次生孔隙的成因

生油岩生成的油气，必须运移到储集层中贮存起来，这样油气才可成藏，而岩层的孔隙度是其储集性好坏的重要标志，次生孔隙在此更是有极重要的意义(因为随着岩层的埋深，成岩作用不断在进行，原生孔隙将减少，次生孔隙将在储油方面扮演重要角色)，因此，笔者着重论述次生孔隙的成因及其相关问题。     

岩石变形所反映的地震作用过程--第13届国际变形机理、流变学和构造学学术会议概述

简要介绍了第13届国际变形机理、流变学和构造学学术会议的概况和特点，综述了地震变形作用的研究现状。