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991.
A combination of analytical techniques, including thin-section observations, scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis, was applied to study the nature and origin of an adhesive used for mounting flint sickle blades to a wooden handle, recovered from early Eighteenth Dynasty culture layers of the multi-layer settlement at Tell el Dab'a, Lower Eygpt. The results obtained from these investigations led to the conclusion that the adhesive is a pure lime plaster, thus providing the oldest evidence for the use of this material as a binding agent so far known in ancient Egypt. 相似文献
992.
Some 630 Roman silver coins excavated at Augusta Raurica (Switzerland) have been analysed by non-destructive X-ray fluorescence and X-ray diffraction. Furthermore, the density and the weight have been determined. The measured average density of plated and massive depletion-silvered coins is lower than the density calculated from the chemical composition, whereas massive coins display equal values for both of the densities. Based on experimental X-ray investigations of modern silver (tempering, acid treatment, production of corrosion layers), the nature of corrosion products on silver, their impact on surface analysis, and aspects of wearing-off by circulation are briefly discussed. 相似文献
993.
M. H. Suryanarayana 《Development and change》1997,28(4):771-789
Although assessments by conventional macro measures show considerable improvement in food security in India, the levels of cereal consumption and calorie intake of even the general population are still below the normative threshold limits. This article brings out the dynamics of changes in institutional and production conditions and their implications for consumption patterns and food security at the micro level. The article uses empirical evidence to raise a number of issues, and calls for emphasis on investment in human capital by way of improvements in food and calorie intake for efficiency and economic growth. 相似文献
994.
SPATIAL DEPENDENCY OF SEGREGATION INDICES 总被引:3,自引:0,他引:3
David W.S. Wong 《The Canadian geographer》1997,41(2):128-136
A few researchers have mentioned the scale sensitivity of segregation index, D. In this paper, I discuss analytically and empirically why using large enumeration areal units usually results in low segregation measures, and using small areal units produces relatively high segregation measures. The discussion is also applicable to the multi-group variant of D. A major finding is that if people of the same ethnic groups are positively spatially auto-correlated, increasing the size of areal units of analysis may not lower D initially, because only people of the same group are added. But enlarging the areal units subsequently may include population of other ethnic groups, and therefore could lower D. However, if the boundaries of the larger enumeration units are drawn to include only population of the same group, then D will not change significantly. Both the spatial autocorrelation of ethnic group population and zonal pattern are critical factors in determining the scale sensitivity of D. 相似文献
995.
996.
997.
Norman R. Cloutier 《Journal of regional science》1997,37(3):459-478
The empirical analysis in this paper explores the interurban variation in family income distribution. The results point to increasing urban development, rising female-headship, a widening educational distribution, and changes in the industrial and occupational mix as major contributing factors to rising inequality. However, the increase in the relative number of multiple worker families was a significant mitigating force to rising inequality. A decomposition of 1979 and 1989 cross-sectional models revealed that while changes in urban family and industrial characteristics have been sources of rising inequality, there has been significant structural change in the urban models acting to decrease inequality. 相似文献
998.
Jean-Marc Drouin Patrick Gautier Dalché Fabien Chareix Charles Lenay Monique Cottret Bernard Vandewalle François Laplanche Françoise Waquet Agnès Spiquel Ariane Poulantzas Olivier Martin Sophie Roux Ilana Löwy Françoise Waquet Isabelle Brian Michel Cassan Jean-Marc Rohrbasser Jean-Michel Vienne Marc Renneville Bernard Lahire Mikhaäl Xifaras Bertrand Binoche Stéphane Haber Jean-François Pradeau Noël Bonneuil Marie Jaisson 《Revue de synthèse / Centre international de synthèse》1997,118(4):551-613
999.
Philip R. Israilevich Geoffrey J. D. Hewings Michael Sonis & Graham R. Schindler 《Journal of regional science》1997,37(4):565-590
The sophistication of regional economic models has been demonstrated in numerous ways, most recently in the form of linking several modeling systems or in the expansion in the number of equations that can be manipulated successfully to produce impact analyses or forecasts. In this paper, an alternative perspective is employed. What do regional macro-level forecasts indicate about the process of structural change? A new methodology is illustrated that enables analysts to make forecasts of detailed structural change in the interindustry relations in an economy. Using a regional econometric input-output model developed for the Chicago metropolitan region, derived input-output tables are extracted for the period 1975–2016. These tables are then analyzed to determine the forecasted direction of structural changes for the region. The innovation illustrated here is based on a model that exploits the general equilibrium spirit of computable general equilibrium models through the adjustment of input coefficients to clear markets. 相似文献
1000.
In Part I of this paper (Smith and Hsieh, 1997) a programming formulation of steady states was developed for gravity-type interactive Markov chains in terms of their associated spatial-flow chains. These results are here applied to analyze the stability properties of interactive Markov chains. In particular, the objective function for this programming formulation is shown to constitute a Lyapunov function for an appropriately defined continuous-time version of spatial-flow chains. The Lyapunov stability properties of these spatial flows are then shown to yield corresponding stability properties for the continuous-time versions of interactive Markov chains. In particular, these processes always exhibit global convergence to steady states. Finally, it is shown that when steady states are unique, these convergence results are inherited by those interactive Markov chains that are 'sufficiently close' to their continuous-time versions. 相似文献