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The author presents an approach to the analysis of labor migration that incorporates the role of market wage variability as a source of information in individual migration decisions. "The focus...is on quantifying the effects of the origin market acting through amenities and the share of market-specific wage variability as it affects forecasts of alternative wages and forecast precision. A subsample of employed males...from the [U.S.] National Longitudinal Survey of Youth (NLS) age 16 to 22 years is used for estimation. The empirical results are consistent with the theoretically predicted relationship between migration propensities and regional differences in the information content of wages. In addition, the results provide evidence that risk aversion deters migration given uncertainty, measured by forecast precision, about alternative market wage levels."  相似文献   
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Advanced data capture techniques, cost-effective data processing, and visualization technologies provide viable solutions for the documentation of archaeological heritage and material culture. Work at the UNESCO World Heritage site of Çatalhöyük has demonstrated that new digital approaches for capturing, processing, analyzing, and curating stratigraphic data in 3D are now feasible. Real-time visualization engines allow us to simulate the stratigraphy of a site, the three-dimensional surfaces of ancient buildings, as well as the ever-changing morphology of cultural landscapes. Nonetheless, more work needs to be done to address methodological questions such as follows: can three-dimensional models and stratigraphic relationships, based on 3D surfaces and volumes, be used to perform archaeological interpretation? How can a 3D virtual scenario become the interface to cultural data and metadata stored in external online databases? How can we foster a sense of presence and user embodiment in the simulation of ancient cities and archaeological sites? This article aims to provide viable solutions to the methodological challenge of designing a comprehensive digital archaeological workflow from the data acquisition and interpretation in the field to a three-dimensional digital data curation based on interactive visualization, searchable 3D data, and virtual environments. This work describes the results we achieved developing the application Dig@IT, a multi-platform, scalable virtual reality tool able to foster archaeological data analysis, interpretation, and curation in a realistic and highly interactive virtual environment.  相似文献   
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The Irish dimension of Anglo-American relations is a relatively marginalized aspect of the historiography of transatlantic studies. Historians have focused on the role of the Clinton administration in the Northern Ireland “peace process” but previous American contributions also warrant attention. As the Speaker of the United States House of Representatives, Thomas P. “Tip” O’Neill was one of the most prominent Irish-American politicians. This article demonstrates O’Neill's attempts to ensure that the American contribution to the Anglo-Irish process steadily increased, despite the transition from arguably his natural political ally in the President Jimmy Carter administration to President Ronald Reagan in 1981. O’Neill's interest in Northern Ireland and position as speaker helped ensure that Carter's promise of financial aid to Northern Ireland in 1977 following progress in the political process was fulfilled in March 1986.  相似文献   
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In this study a structural investigation on the ogival masonry domes is performed with particular attention to the significant debate between mathematicians and architects mainly of the French and Italian schools that characterized the 18th century. In this period, analytical approaches to investigate the static of dome structures were developed concurrently for the affirmation of the proportional methods, as reported in several architectural treatises in which graphical constructions for the design of masonry domes can be found. It is well known that Carlo Fontana, in 1694, was the first to show in detail the geometrical rules for the design of a masonry dome. Later, in 1760, the Italian architect Bernardo Antonio Vittone proposed some variations to the rules written by Fontana in order to increase the height of the dome and the slope of the meridian section at the intersection with the lantern. In this study, Vittone’s dome has been analyzed and compared with Fontana’s dome by means of an analytical approach that also considers the influence of the lantern at the top. The obtained results confirm that Vittone’s rules lead not only to architectural, but also structural improvements.  相似文献   
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Since 2001 when Lesotho embraced the neoliberal African Growth and Opportunities Act that offers preferential access to the US market, its garment industry has expanded dramatically to become the nation’s leading employer. Elsewhere, large-scale employment of women in low-paid factory jobs has entailed spatial restructuring of gender and age relations. Lesotho is a distinctive context, with socio-spatial relations historically adjusted to male labour migration, high levels of contemporary male unemployment and alarming AIDS prevalence. Based on semi-structured interviews with 40 female factoryworkers and 37 dependents, this article applies a relational time-space analysis to explore how financial and spatio-temporal aspects of factory employment articulate to alter women’s relationships with those for whom they have culturally determined responsibilities: their children, those suffering from ill health and their (generally rural) home communities. The analysis highlights that such employment is not merely adding to women’s responsibilities, but transforming how they are able to undertake social reproduction, as practical, social and emotional roles are converted to largely financial obligations.  相似文献   
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Ancient human migrations provide the critical genetic background to historical and contemporary human demographic patterns. However, our ability to infer past human migration events, especially those that occurred over rapid timescales, is often limited. A key example is the peopling of Polynesia, where the timing is relatively well defined, but the exact routes taken during the final stages and the source populations are not. Here, we discuss the technical limitations of current methods for inferring rapid human migration events, using the final stages of Polynesian migration as an example. We also introduce a promising new proxy method to infer human migrations—patterns of bacterial evolution within ancient dental calculus (calcified plaque). While we focus on Polynesia, this method should be applicable to other past migrations, enhancing our understanding of human prehistory and revealing the crucial events that shaped it.  相似文献   
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