全文获取类型
收费全文 | 5378篇 |
免费 | 155篇 |
出版年
2020年 | 59篇 |
2019年 | 93篇 |
2018年 | 93篇 |
2017年 | 138篇 |
2016年 | 128篇 |
2015年 | 87篇 |
2014年 | 94篇 |
2013年 | 1914篇 |
2012年 | 93篇 |
2011年 | 125篇 |
2010年 | 109篇 |
2009年 | 100篇 |
2008年 | 91篇 |
2007年 | 86篇 |
2006年 | 70篇 |
2005年 | 57篇 |
2004年 | 75篇 |
2003年 | 70篇 |
2002年 | 60篇 |
2001年 | 61篇 |
2000年 | 63篇 |
1999年 | 104篇 |
1998年 | 69篇 |
1997年 | 51篇 |
1996年 | 48篇 |
1995年 | 39篇 |
1994年 | 45篇 |
1993年 | 56篇 |
1992年 | 40篇 |
1991年 | 38篇 |
1990年 | 50篇 |
1989年 | 46篇 |
1988年 | 42篇 |
1987年 | 57篇 |
1986年 | 46篇 |
1985年 | 57篇 |
1984年 | 64篇 |
1983年 | 67篇 |
1982年 | 60篇 |
1981年 | 50篇 |
1980年 | 82篇 |
1979年 | 54篇 |
1978年 | 63篇 |
1977年 | 72篇 |
1976年 | 66篇 |
1975年 | 61篇 |
1974年 | 44篇 |
1973年 | 34篇 |
1972年 | 33篇 |
1970年 | 41篇 |
排序方式: 共有5533条查询结果,搜索用时 15 毫秒
991.
James E. Miller 《Journal of Modern Italian Studies》2013,18(1):15-20
Abstract While open to criticism on many levels, the foreign policy of Italy under Silvio Berlusconi does not deviate in many significant ways from traditional approaches, especially on its management of Italy's relations with the United States and the European Union. Italy's ‘exceptionalism’ is also similar to that of many other European states. 相似文献
992.
993.
994.
DESIRABLE STRENGTH DISTRIBUTION FOR ASYMMETRIC STRUCTURES WITH STRENGTH-STIFFNESS DEPENDENT ELEMENTS
Recent studies have shown that for many reinforced concrete lateral force-resisting elements (LFRE) stiffness is dependent on strength, and as a result strength assign-ment to these elements would affect both the strength and stiffness distributions in a structure. As a consequence, stiffness distribution cannot be considered known prior to strength assignment. This implies that in assigning strength to LFRE, the designer has the ability not only to prescribe the strength distribution, but also indirectly control the stiffness distribution in the structure. In this paper, a study is made on the seis-mic performance of a number of single-story structures to reconfirm that the “balanced CV-CR location” criterion, previously suggested by the writers, constitutes a desirable strength/stiffness distribution for minimising torsional response of asymmetric reinforced concrete structures. 相似文献
995.
The application of FT‐Raman spectroscopy and visible Raman microscopy to the non‐destructive analysis of pigment specimens excavated from Tell el Amarna by Flinders Petrie in the 1890s has provided information about the chemical composition of the materials used by XVIIIth Dynasty artists in the New Kingdom at the time of King Akhenaten, c. 1340 bc. Comparison of the Raman spectra of the samples labelled ‘red and yellow ochre’ with documented, archival material from geological collections provided a clear indication of the materials used in the iron(III) oxide/hydroxide system, including α‐hematite, goethite, maghemite, magnetite and lepidocrocite. The yellow–orange specimen labelled ‘realgar’ proved to be a mixture of realgar and pararealgar; since the specimen had been sheltered from light since its excavation, this could indicate that the ancient Egyptian artists recognized the colour variation and may have used this to effect in their decorations. A specimen of yellow ochre contained goethite, α‐FeO.OH, with particles of crystalline, highly ordered graphite; in contrast, the red ochre specimens contained amorphous carbon particles. 相似文献
996.
997.
This research examines state support for higher education by first ascertaining the amount supplied and demanded of this service. The approach assumes that supply and demand occur simultaneously, and that each is affected by higher education spending policies among the states. We argue that enrollment is the most satisfactory proxy for both supply and demand. State policy is measured as expenditure effort. We estimate three time-series equations using two-stage least squares regression with data for the years 1986–95. In the final equation, supply/demand (enrollment) emerges as the strongest predictor of state spending effort. Commitment to higher education (effort) is also especially sensitive to variations in the number of employees (per student). Employee costs clearly are a major factor in fueling increases in state higher education spending effort. State per capita income exerts a negative effect on the final dependent variable. Poor states exert greater financial effort in support of their colleges and universities than do more affluent states. 相似文献
998.
Stephen W. Silliman 《Journal of Anthropological Archaeology》2001,20(4):379
Many recognize that labor was a central feature of colonialism, especially in the Americas, but few have considered the anthropological implications of labor for interpreting colonialism. A new theoretical perspective involves conceptualizing labor as practice and as a social, rather than simply an economic, phenomenon. Building on theories of practice, labor can be defined as a colonial imposition and attempt at social control and as a medium of agency and resistance for those laboring. Although historical documents provide solid information on the structure and implementation of labor from the top down, archaeological research is often required to access the native experience of labor from the bottom up. To develop the labor-as-practice approach, I present a case study of the 18th- and 19th-century California missions that integrates historical data on regional mission labor organization with archaeological data from the specific site of Mission San Antonio de Padua in southcentral California. The results provide new insights into the interpretation of Mission San Antonio's archaeological record, fresh perspectives on the complexity of material culture in colonial and pluralistic settings, and increased appreciation for the role of colonial labor in structuring the spatial and material aspects of culture contact, colonialism, and daily life in the past. 相似文献
999.
James Der Derian 《International affairs》2000,76(4):771-788
Strategic discourse and the use of force in the twentieth century have become increasingly virtual. Leading the way, as the dominant actor in global politics, is the United States, whose diplomatic and military policies are now based on technological and representational forms of discipline, deterrence, and compellence that could best be described as virtuous war . At the cyborg heart of virtuous war is the technical capability and ethical imperative to threaten and, if necessary, actualize violence from a distance—with no or minimal casualties. Using networked information and virtual technologies to bring 'there' here in real time and with near-verisimilitude, virtuous war exercized a comparative as well as a strategic advantage for the digitally advanced. It has already become the 'fifth dimension' of US global hegemony, with a very real gap opening between technological capability and strategic value on the one side, and theoretical understanding and ethical awareness on the other. There is a clear and present need to develop a virtual theory that can assess the perils and promises of this intimate relationship between modes of representation and violence. 相似文献
1000.
The Richards site is attributed to the Philo phase of the Fort Ancient tradition of the Ohio Valley area. Human skeletal material from the site shows evidence of peri‐ and post‐mortem taphonomic changes, including cut marks, burning and fracturing. Previous analyses have discussed explanations for these changes, including secondary burial, ritual destruction and cannibalism. Researchers have theorised that, allowing for differences in anatomy among species, humans and animals butchered for the same purpose (consumption) will show similar patterns of taphonomic changes associated with butchery. The human remains at the Richards Site were disposed in general midden pits containing mixed cultural debris and faunal remains. White‐tailed deer (Odocoileus virginianus) constitutes approximately 60% of all the faunal bone, indicating that it was a major food resource. To test a cannibalism explanation, a comparative analysis of human‐induced taphonomy in human and deer skeletal remains was performed, using chi‐square and odds ratio tests. If humans were being used as a food resource, the pattern of butchery seen would mirror that of the deer. The analysis described here compares the patterns of treatment and disposal of human and deer skeletal elements at the Richards site, to test whether both species were used as food resources. Similar types of evidence for human‐induced taphonomic changes, including cutting, chopping, burning and breakage, can be seen in both species. However, results indicate that, in general, human remains show much more evidence of perimortem treatment than do deer remains. In fact, the common odds ratio for perimortem treatment in all bones is 3.25, indicating that a human bone is 3.25 times as likely as a deer bone to be affected by burning, cutting or chopping. This probably indicates that perimortem treatment of humans was greater than that necessary simply for butchering for consumption. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献