全文获取类型
收费全文 | 206篇 |
免费 | 19篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2021年 | 1篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 28篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 45篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有225条查询结果,搜索用时 31 毫秒
121.
V Martínez-Calzada A Rodríguez-Castellanos D Samayoa-Ochoa F.J Sánchez-Sesma M Carbajal-Romero 《Journal of Earthquake Engineering》2019,23(2):356-376
Several studies indicate that marine seismic activity is vast. Actually, about 90% of all natural earthquakes have epicenters in o_shore areas and may cause damage to subsea and floating structures. In this numerical study the indirect boundary element method is used to analyze the influence that some parameters, involved in this kind of problems, have on the dynamic response of marine waters under the incidence of theoretical seismic events. According with the results, the seismic amplifications depend on the seabed configuration and produce displacements which can be a serious concern. 相似文献
122.
This study addresses the problem of evaluation of strength of masonry walls. In-plane behavior of masonry panels has been studied under monotonic diagonal-compression and shear-compression loading in quasi-static test facility. The results of 35 laboratory and in situ tests are analyzed to show that in the case of the diagonal compression test results are lower than the strength of masonry walls evaluated trough the shear-compression test, highlighting the problem of choosing the test which best simulates to the real behavior of the masonry when stressed by lateral loads. A presentation is also given of the results of a F.E. investigation for shear strength evaluation of masonry walls. F.E. modeling non-linear procedure was used for the representation of masonry panels. The numerical simulations are compared with experimental results and the reliability of the different finite element models is discussed, thus confirming the different shear strength values measured in the experimental campaign. 相似文献
123.
In spite of ambitious modernization plans of the government, structural change in Russia is not proceeding in the direction of highly developed economies. Part of the lag in the tertiarization process can be explained by the fact that, as during the Soviet period, the role of services in the economy is still ignored, particularly regarding innovation. This paper aims to contribute to the analysis of the evolution of services in Russia since the mid-1990s and its future prospects by compiling data from the World Bank, the International Labor Organization, Rosstat, and the World Input–Output Database. Two complementary and novel perspectives are adopted: a production system perspective and a spatial perspective. Regarding services in the Russian production system, comparison of interindustry linkages reveals that, in addition to traditional relevant activities like wholesale/retail trade and transport and communications, business services are acquiring great importance as production process inputs. Concerning the spatial perspective, we observe a greater presence of non-market services in less densely populated federal districts, while strategic service activities are highly concentrated in the most dynamic ones. Analysis of major Russian cities confirmed the trend of business services concentrating in densely populated and highly innovative cities. In brief, services, and in particular business services, can be a means to boost innovation and growth in Russia, but more attention from political leaders is necessary for these activities. The modernization process should abandon its current “high-technology industry myopia” and take into consideration the innovative, and especially, the knowledge-diffuser role, that services can exert. 相似文献
124.
Jorge de Torres Rodríguez 《African Archaeological Review》2017,34(2):225-248
Although the Gondärine period of Ethiopian history is relatively well-known due to local and foreign historical texts, and the architectural remains of the Solomonic dynasty, little is known about the material culture of the communities who inhabited the core area of this kingdom between the sixteenth and eighteenth centuries. This paper deals with the historical pottery documented in the Lake Tana region, summarizing the results of a nine-year project in the area of Gondär and linking it with materials from nearby areas. A comprehensive study of the ceramic remains has been undertaken with a combination of ethnographic, written, and archaeological sources, providing a first chronological and typological framework for this pottery, and some hints about the reasons for the changes detected throughout time related to the consolidation of a centralized Ethiopian monarchy in the mid-sixteenth century. 相似文献
125.
Pier Francesco Cassoli Antonio Tagliacozzo 《International Journal of Osteoarchaeology》1997,7(4):303-320
Grotta Romanelli is one of the most important sites of the Italian palaeolithic. It contains a lithic industry from the Final Epigravettian, examples of rock and mobiliary art and numerous bone remains, among which were abundant remains of birds. Approximately 32 000 bird bones from over 3650 individuals and 109 species were identified. The most common species were bustards, Otis tetrax and O. tarda, and three species of goose, Anser fabalis, A. albifrons and Branta bernicla. Traces of butchering and burning were evident on numerous bones. The nature and location of the cut marks and burning is described here. The analysis has involved mostly the hind limbs and the shoulder girdle where traces are most numerous. The cut marks reflect a codified sequence of actions of disarticulation and dismemberment. © 1997 John Wiley & Sons, Ltd. 相似文献
126.
127.
The children of Kaminaljuyu: Isotopic insight into diet and long distance interaction in Mesoamerica
Lori E. Wright Juan Antonio Valdés James H. Burton T. Douglas Price Henry P. Schwarcz 《Journal of Anthropological Archaeology》2010
Known for its spectacular tombs and adobe talud–tablero architecture, the highland Guatemalan city of Kaminaljuyu is key to models of long distance interaction in Mesoamerica. We use stable isotopic data from human bone, dentine and tooth enamel to reconstruct Kaminaljuyu’s dietary history. Stable carbon isotope ratios and alkaline earth ratios of enamel carbonate indicate a decline in maize consumption from Preclassic to Classic periods, perhaps due to the desiccation of Lake Miraflores, which was used to irrigate Late Preclassic fields. Stable oxygen and strontium isotope ratios in enamel shed light on the geographic origin of Early Classic skeletons, and show that the central skeletons in the tombs were local children. However, four decapitated skulls and two peripheral skeletons show enriched oxygen ratios, similar to Lowland Maya sites. Strontium isotope ratios indicate that most of these are from an area underlain by Cretaceous limestones; one is from a metamorphic region. Two individuals may have traveled to or from Central Mexico. The greater evidence for lowland individuals among the tomb skeletons implies that political connections with the Maya area were more significant to elites at Kaminaljuyu than was direct contact with Central Mexico. 相似文献
128.
Being competitive requires continuously performing product and process innovations nowadays. Because of this reason, the absorption of externally generated R&D is increasingly important for companies. It is well known that companies differ regarding their aptitude for knowledge absorption. This paper aims at the identification of different firm profiles by means of the identification and valuation of drivers that support the absorption of external R&D. For this, we have carried out an empirical work that is based on a random sample of companies located in the northern Spanish county of Biscay. We identify four company conglomerates according to their attitude to absorb externally generated R&D. 相似文献
129.
José Antonio Belso-Martínez 《European Planning Studies》2006,14(6):791-810
This paper seeks to enhance the understanding of the role of the industrial districts in the internationalization process of small and medium-sized enterprises (SMEs). The study focuses essentially upon the following issue: Can the location inside industrial districts influence the export performance and export intensity of the Spanish SMEs? To address this question, this study draws upon a sample of 285 manufacturing firms located in the Valencian community (a Spanish region) surveyed during the period January 2000 to March 2000. It is shown that industrial district location, marketing differentiation, institutional networks, clients' networks, competitors' networks and global orientation of sector and company have a clear influence on firms export performance and export intensity. The results are basically consistent with the limited previous research. 相似文献
130.
ABSTRACT This paper provides an empirical study of the determinants of income inequality across regions of the EU. Using the European Community Household Panel dataset for 102 regions over the period 1995–2000, it analyses how microeconomic changes in human capital distribution affect income inequality for the population as a whole and for normally working people. The different static and dynamic panel data analyses conducted reveal that the relationship between income per capita and income inequality, as well as between a good human capital endowment and income inequality is positive. High levels of inequality in educational attainment are also associated with higher income inequality. The above results are robust to changes in the definition of income distribution and may be interpreted as a sign of the responsiveness of the EU labor market to differences in qualifications and skills. Other results indicate that population ageing, female participation in the labor force, urbanization, agriculture, and industry are negatively associated to income inequality, while unemployment and the presence of a strong financial sector positively affect inequality. Finally, income inequality is lower in social‐democratic welfare states, in Protestant areas, and in regions with Nordic family structures. 相似文献