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51.
Characterization of a Historical Cannonball from the Fortress of San Juan De Ulúa Exposed to a Marine Environment 下载免费PDF全文
M. Hernandez M. Hernandez‐Escampa C. Abreu J. Uruchurtu M. Bethencourt A. Covelo 《Archaeometry》2016,58(4):610-623
Metallurgical analyses and chemical characterizations were carried out on historical cannonballs from the Fortress of San Juan de Ulúa, Veracruz, México. Cannonballs dating from the 18th and 19th centuries share metallurgical characteristics similar to those of material coming from a shipment of ammunition found in the wreck of a sunken French ship from the battle of Trafalgar. The analyses show that the base material is grey cast iron with a carbon equivalent of 4.94 and a ferritic–perlitic matrix, in which the high phosphorus content has led to the formation of iron phosphide compounds in conjunction with a homogeneous distribution of carbon graphite flakes of Type C. In addition, corrosion products from samples revealed the presence of various crystalline iron compounds (X‐ray diffraction), mostly highly chlorinated iron compounds identified as akaganeite. X‐ray fluorescence identified various characteristics of the corrosion products as a function of the sampling depth. FT–IR spectroscopy revealed that the main difference between the corrosion products (internal and external) is determined by the number of organic species. Differential scanning calorimetry corroborated that these corrosion products are thermally stable compounds at elevated temperatures. 相似文献
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A Box Containing Carpenter's Accessories from The Akko 1 Shipwreck,Israel: Archaeometallurgical Analysis of Surviving Ironwork 下载免费PDF全文
The Akko 1 shipwreck was an Egyptian armed vessel, built at the beginning of the 19th century. A wooden saw handle and a box containing iron nails and two split pins were discovered towards the stern. Given their function, location and context, these were part of the ship's carpenter's tools and accessories. A methodology was developed for conducting systematic metallurgical analysis in order to understand the manufacturing process of the surviving ironwork items, as well as to enlarge our knowledge regarding ironworking technologies during the early 19th century. Such methodology may assist in the future understanding of the technological evolution of similar wrought‐iron objects. The results demonstrated that the artefacts have a wrought‐iron heterogeneous microstructure and were manufactured by hot‐working prior to surface hardening by pack carburization. 相似文献
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LOCALIZATION AND INDUSTRY CLUSTERING ECONOMETRICS: AN ASSESSMENT OF GIBBS MODELS FOR SPATIAL POINT PROCESSES 下载免费PDF全文
The objective of this paper is to assess an approach to statistical modeling of point referenced establishment data that permit inclusion of “environmental” or establishment‐specific covariates and specific forms of interestablishment interaction. Gibbs models are used to decompose the conditional intensity of the spatial point process into trend and interaction components. The trend is composed of access measures (primarily different classes of roads) and three different interaction processes are tested: Geyer, area interaction, and Strauss hard core. While the models used have proved to be useful in ecology, we are unaware of any applications to establishment or firm data. In empirical application, the models yield intuitively appealing results for the trend component, and the ability to specify the interaction component gives deeper insights into interestablishment spatial dynamics than any previously published methods. 相似文献
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We examine the relationship between individual commuting behavior and household responsibilities, with a focus on gender differences in that relationship. Using the Dutch Time Use Survey for the years 2000 and 2005, we analyze the relationship between commuting time, home production, and childcare. To deal with reverse causality, we use Propenstity Score Matching techniques to obtain imputed data for individuals. We find that the effect of home production on commuting time for women is more than double that for men, while childcare time has an effect on women's commuting behavior only. Our results shedding light on the Household Responsibility Hypothesis. 相似文献
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This paper develops a new methodology to predict the interregional and interindustry impacts of disruptive events. We model the reactions of economic agents by minimizing the information gain between the pre‐ and postevent pattern of economic transactions. The resulting nonlinear program reproduces, as it should, the pre‐event market equilibrium. The methodology is tested further by means of a comparison of this base scenario with two regional production shock scenarios and two interregional trade shock scenarios. The outcomes show a plausible combination of partially compensating demand, supply, and spatial substitution effects, which justifies the further development, testing, and application of this new approach. 相似文献
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Jan Stöckmann 《国际历史评论》2016,38(5):1055-1080
This paper examines the dynamics of internationalist and nationalist political thought in the formation of International Relations (IR) scholarship in Germany during the early twentieth century. It argues that while liberal internationalism played a significant role in shaping the discipline, IR scholars were often devout nationalists and worked for their government rather than for international peace. German institutions for the study of IR, like their Anglo-American counterparts, were founded in the aftermath of the First World War. Celebrated during the 1920s as ‘bulwarks of democracy’, they were nationalised by the Nazi government, lost their academic profile and since then have been largely forgotten. This paper explains the origins of IR research at the Institut für Auswärtige Politik, based in Hamburg and directed by Albrecht Mendelssohn Bartholdy, as well as at the Deutsche Hochschule für Politik, led by Ernst Jäckh in Berlin. Formally inaugurated in 1923 and 1920 respectively, both institutions drew on pre-war intellectual traditions as well as wartime networks. In light of recent re-appraisals of inter-war IR scholarship in other countries, the German case offers new and important insights into the complex intellectual traditions of what has traditionally been oversimplified as a first ‘great debate’ between ‘idealists’ and ‘realists’. 相似文献