Should Women Count? A Context for the Debate*

Much recent feminist geographical scholarship emphasizes the utility of qualitative research methods; yet, a significant proportion of feminist research in geography is quantitative. Geographers' engagement with the ideas of feminist theorists has shed new light on the relationship between epistemology, methodology, and objectivity, which in turn has facilitated a reexamination of feminist uses of quantification. In providing a context for the debate over quantitative and qualitative methods, we argue that each has a place in feminist geographical research.     

石油物探技术的进展

概括地论述了石油物探技术在80年代的新进展.与70年代相比,80年代石油地球物理勘探技术取得了前所未有的成就;同时,也存在不少亟待解决的问题,且难度相当大.这些问题正是90年代所面临的研究课题.     

Simple analytical Green's functions for ray perturbations in layered media

The total Green's function for two-point boundary-value problems can be related to the propagator for initial-value problems. A very simple expression for the Green's function is obtained when the unperturbed medium may be described by material with a constant gradient in quadratic slowness. The derivation requires a correct understanding of assumptions made in the propagator solution. Expressions are also obtained for Green's function in multilayered media.     

Personal Narratives as Interactive Texts: Collecting and Interpreting Migrant Life-Histories*

Life-history or personal narrative techniques have considerable potential as a way of recovering hidden histories, contesting academic androcentrism, and reinstating the marginalized and dispossessed as makers of their own past. Drawing on a large methodological literature on life-history collection, and applications of these techniques in Africa, we argue that geographers might explore these methodologies as a means of recovering lost geographies and venting alternative voices in academic texts. Drawing on our own project on Swazi migrant women, we suggest that life-histories cannot, however, be seen purely as vehicles for the delivery of uncontaminated fact about the past. Rather personal narratives should be viewed and interpreted as interactive texts. This leads us to a consideration of a number of methodological and interpretive issues surrounding life-history collection: the positional advantages of insider status, the “terrible assymetries” of the interview process, and the power (and pitfalls) of narrative forms of representation.     

A laser-photolysis fragment-fluorescence (LPFF) method for the detection of gaseous nitric acid in ambient air

The development and first tests of a novel method for the direct, sensitive, selective, and fast detection of gaseous nitric acid in air are described. The detection method is based on the laser-photolysis fragment-fluorescence (LPFF) method using 193 nm (ArF) laser light. The photolysis process yielding OH fluorescence has been thoroughly investigated. Up to now, the method has been found to be practically free of interferences. The mixing ratio for nitric acid is measured on-line with a detection limit of about 0.1 ppbv for an accumulation time of the signal of 10–15 min. A number of tests and field measurements were performed to demonstrate the feasibility and limits of the described detection method.     

Reliability level III method in design of square pillar resting on weak floor stratum

Summary Current methods of design of pillars resting on weak floor strata involve only a deterministic, conventional safety factor calculation, based on material parameters treated as the mean values taken from observations. In a case where high parameters variability occurs, these methods may lead to fatal design errors resulting in excessive pillar settlement and roof falls. Therefore, to include the influence of parameters quality, the new approach based on reliability level III method was developed. Consideration was given to the identification of the system parameters importance, and to density function for the safety factor treated as a random variable. Design procedure involving floor probability of failure was illustrated by numerical examples.     

用油田压裂资料估算应力值

本文比较了从油田压裂资料获得的应力值与专门的水压致裂应力测量结果。研究结果表明,前者的最小水平主应力可以和后者的精度相当,最大水平主应力的精度略低。以长庆油田岭261—2井1985年11月15日实际压裂记录结果和吉林油田东33—35井的压裂记录为例,提出了处理油田资料的方法,给出了相应的处理结果     

The application of cellular automata to the erosion of landforms

Two approaches to modelling surface erosion are described which can be used to explain the development of geomorphological features. The first approach uses non-linear wave theory and shows how surface gradient discontinuities can arise as the erosion of an initially smooth surface proceeds. For isotropic erosion, surface shapes may be predicted by a simple application of the Huyghens wavefront construction and Snell's law at media boundaries. A second approach uses a computational cellular method. The general shapes predicted by the computer simulations are shown to agree with those determined from the wave approach. The application of the cellular method to problems of geomorphological interest are discussed.     

自记水位仪的数字化改造

本文详细叙述了采用光电编码和微机技术对自记水位仪进行数字化改造的方案选择、理论计算和改造实践。