Transport of suspended solids from a karstic to an alluvial aquifer: the role of the karst/alluvium interface

This study focuses on the coupled transport of dissolved constituents and particulates, from their infiltration on a karst plateau to their discharge from a karst spring and their arrival at a well in an alluvial plain. Particulate markers were identified and the transport of solids was characterised in situ in porous and karstic media, based on particle size analyses, SEM, and traces. Transport from the sinkhole to the spring appeared to be dominated by flow through karst: particulate transport was apparently conservative between the two sites, and there was little difference in the overall character of the particle size distribution of the particulates infiltrating the sinkhole and of those discharging from the spring. Qualitatively, the mineralogy of the infiltrating and discharging material was similar, although at the spring an autochthonous contribution from the aquifer was noted (chalk particles eroded from the parent rock by weathering). In contrast, transport between the spring and the well appears to be affected by the overlying alluvium: particles in the water from the well, showed evidence of considerable size-sorting. Additionally, SEM images of the well samples showed the presence of particles originating from the overlying alluvial system; these particles were not found in samples from the sinkhole or the spring. The differences between the particulates discharging from the spring and the well indicate that the water pumped from the alluvial plain is coming from the karst aquifer via the very transmissive, complex geologic interface between the underlying chalk formation and the gravel at the base of the overlying alluvial system.     

数值预报MAPS模式并行化移植初探

通过武汉区域气象中心数值预报MAPS（Mesoscale Analysis and Process System)模式并行化移植的实例，介绍了如何使用共享内存，消息传递的并行方式进行数值预报模式并行化工作，对不同条件下并行MAPS模式的并行效率进行了比较。结果表明，对数值预报MAPS模式完成程序优化和共享内存方式以及消息传递方式的并行化等工作后，MAPS模式运算时间大为缩短，满足预报业务时效的要求。     

电子探针自动控制系统

该系统用新型微机２８６／３８６／４８６／５８６通过ＲＳ－２３２Ｃ异步串行口向电子探针仪的控制机发送各种控制命令，接收相应的回传数据，实现了对电子探针仪的自动控制；用Ｃ＋＋语言开发了新的电子探针分析软件，对测量和修正计算过程进行了优化，增加了自动排序、打印分析报告等功能，提高电子探针分析速度３倍。     

关于山谷冰川冰-岩界面地貌过程与冰川动力耦合模式——以中天山冰川为例

对冰川侵蚀形态的观测与分析得知：（１）冰川槽谷中冰川擦痕的大小和密度在中心较大，鲸背岩出现在冰川槽谷的中部，羊背石发育在槽谷两侧。因此，可以将槽谷分为强烈磨蚀的中部和弱磨蚀而强拔蚀的两侧。（２）冰坎的纵剖面上，迎冰面可见鲸背岩、羊背石以及倾角２０°的剪切裂隙；背冰面以拔蚀为主，见倾角４０°的张性裂隙。沿冰川槽谷纵向，剪切裂隙出现在压缩部位，张裂隙出现在伸张部位。它反映出冷底冰川的动力特性与冰床基岩的受力机制的一致性。     

Territorial justice in unified Germany: Financial equalization, the Länder and the Federal Constitutional Court

Geographers have traditionally been interested in the issue of territorial justice conceived in terms of distributional equality. The German constitution incorporates a concept of financial equalization with the objective of creating equivalent living conditions throughout the federal territory. This primarily involves the redistribution of finance, the regulation of which has been a continual source of conflict. The paper looks at the role of the Federal Constitutional Court in mediating such conflict. The Court is the ‘supreme guardian of the constitution’ and a highly influential policy-making institution within the German political system. Commentators have described a process of the judicialization of politics, with an increasing number of important political decisions being taken by the Court, rather than in Parliament. The decisions of the Court within the sphere of financial equalization are examined in this light. Further, the particular relevance of a geographical perspective in this regard is highlighted.     

Investigating Travel Behavior of Nondriving Blind and Vision Impaired People: The Role of Public Transit

Our purpose is to explore the travel behavior of blind or vision impaired people, focusing in particular on travel by bus. We differentiate the sample depending on the availability of a household car. We examine perceptions of and attitudes toward existing transit and various transit characteristics, highlighting features that seem to be frustrating or difficult. Finally, we have travelers evaluate the potential usefulness of various assistive devices, including electronic information that gives navigational assistance.     

Non-ionic surfactants adsorption: structure and thermodynamicsAdsorption des tensioactifs non ioniques : structure et thermodynamique

Adsorption of non-ionic surfactants from aqueous solutions has been studied for years because of its industrial relevance. These surfactants, made of an aliphatic part attached to a hydrophilic and polar chain, play an important role in diverse applications. Modelling of the adsorption mechanisms of surfactants has traditionally been based on the interpretation of adsorption isotherms. However, this first level of investigation is not sufficient for a complete understanding. Direct inspection of the adsorbed layer of non-ionic surfactant molecules at the solid–liquid interface is needed. This is an active field of research for almost 15 years, even if the subject is not completely settled down. The aim of this paper is to present a short review of this topic. I will restrict this paper to the case of non-ionic adsorption onto hydrophilic or polar solid interfaces. In the first part, I comment some experimental studies of non-ionic adsorption layer, including fluorescence spectroscopy, neutron scattering and atomic force microscopy. In the second part, a theoretical discussion about thermodynamics of adsorption is presented. A model involving an aggregative adsorption process is proposed. This last part will permit to raise some interesting questions concerning the role of the so-called ‘normal interaction’ (surfactant/solid interaction) to select the optimal surface aggregate curvature. To cite this article: P.E. Levitz, C. R. Geoscience 334 (2002) 665–673.     

Analytical expression for fresnel volumes and interface fresnel zones of seismic body waves. Part 1: Direct and unconverted reflected waves

Summary Fresnel volumes, plane-sectional Fresnel zones and interface Fresnel zones of direct and unconverted reflected waves are studied. Exact analytical expressions for various parameters of Fresnel volumes and Fresnel zones are derived and discussed. Among others, these expressions are related to semi-axes of Fresnel zones, to overshooting and penetration distances, and to the off-ray shifts of Fresnel zones.     

变密度界面模型重力异常反演的B样条函数法

重力异常反演是一个求解第一类非线性积分方程的问题。当三维界面起伏满足│Δｈ│〈０．４１４ｈ０和二维界面起伏满足－ｈ０〈Δｈ〈０．４１４ｈ０时，积分方程的被积函数可Δｈ的级级数形式。