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41.
Environmental and Ecological Statistics - Advances in sensor technology enable environmental monitoring programmes to record and store measurements at a high temporal resolution, enhancing the...  相似文献   
42.
Social wasps and hornets maintain their nest in the dark. The building of the combs by all Vespinae is always in the direction of the gravitational force of Earth, and in each cell's ceiling, at least one 'keystone' is embedded and fastened by saliva. The sensory mechanisms that enable both building of sizeable symmetrical combs and nursing of the brood in the darkness merit investigation, and the aim of the present study was to identify and characterize the 'keystones' that exist in the ceiling and in the walls of the social wasp comb cells. Bio-ferrography was used to isolate magnetic particles on slides. These slides, as well as original cells, were analyzed in an environmental scanning electron microscope by a variety of analytical tools. It was found that both the roof and the walls of each comb cell bear minerals, like ferrites, as well as Ti and Zr. The latter two elements are less abundant in the soil around the nest. Ti and Zr are known to reflect infrared (IR) light. IR imaging showed a thermoregulatory center in the dorsal thorax of the adult Oriental hornet. It is not known yet whether these insects can sense IR light.  相似文献   
43.
The Oriental hornet worker correlates its digging activity with solar insolation. Solar radiation passes through the epicuticle, which exhibits a grating-like structure, and continues to pass through layers of the exo-endocuticle until it is absorbed by the pigment melanin in the brown-colored cuticle or xanthopterin in the yellow-colored cuticle. The correlation between digging activity and the ability of the cuticle to absorb part of the solar radiation implies that the Oriental hornet may harvest parts of the solar radiation. In this study, we explore this intriguing possibility by analyzing the biophysical properties of the cuticle. We use rigorous coupled wave analysis simulations to show that the cuticle surfaces are structured to reduced reflectance and act as diffraction gratings to trap light and increase the amount absorbed in the cuticle. A dye-sensitized solar cell (DSSC) was constructed in order to show the ability of xanthopterin to serve as a light-harvesting molecule.  相似文献   
44.
Journal of Material Cycles and Waste Management - The products of cement–asbestos treated in air at 1100 °C were characterized by a multi-methodological approach to determine:...  相似文献   
45.
Urban sprawl and its evolution over relatively short periods of time demands that we develop statistical tools to make best use of the routinely produced land use data from satellites. An efficient smoothing framework to estimate spatial patterns in binary raster maps derived from land use datasets is developed and presented in this paper. The framework is motivated by the need to model urbanization, specifically urban sprawl, and also its temporal evolution. We frame the problem as estimation of a probability of urbanization surface and use Bayesian P-splines as the tool of choice. Once such a probability map is produced, with associated uncertainty, we develop exploratory tools to identify regions of significant change across space and time. The proposal is used to study urbanisation and its development around the city of Bologna, Emilia Romagna, Italy, using land use data from the Cartography Archive of Emilia Romagna Region for the period 1976–2008.  相似文献   
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This paper considers how differences in the structure and arrangements between the international markets for bauxite, iron ore and copper affect the bargaining strength and division of benefits between buyers and sellers. After describing the characteristic features of each market, and noting the absence of appropriate economic theory to disentangle the issue at hand, an attempt is made to clarify the problem by considering the difference between the markets in terms of five factors - degree of concentration, ability of the parties to inflict losses on each other, varying shares of the raw material in final product prices, structure of the market in which the final products are sold, and the process of trade negotiation.  相似文献   
48.
This paper discusses the development impact of mining and mineral processing on the regions in which they are located. The discussion is organized so as to be of relevance for policy formulation in resource-rich developing countries which consider the exploitation of their mineral wealth. The hypothesis is that mining technology, interpreted in a broad sense, has undergone a profound change since 1900. In consequence, experiences of mineralbased regional development in the industrialized countries around the turn of the century are of little relevance to the Third World in the 1980s. Contemporary mineral ventures have very weak regional development repercussions in the absence of forceful policies specifically directed towards the regional development goal.  相似文献   
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