全文获取类型
收费全文 | 5604篇 |
免费 | 254篇 |
出版年
2020年 | 62篇 |
2019年 | 96篇 |
2018年 | 158篇 |
2017年 | 139篇 |
2016年 | 187篇 |
2015年 | 112篇 |
2014年 | 124篇 |
2013年 | 1660篇 |
2012年 | 145篇 |
2011年 | 170篇 |
2010年 | 149篇 |
2009年 | 155篇 |
2008年 | 121篇 |
2007年 | 126篇 |
2006年 | 124篇 |
2005年 | 66篇 |
2004年 | 83篇 |
2003年 | 86篇 |
2002年 | 58篇 |
2001年 | 86篇 |
2000年 | 67篇 |
1999年 | 78篇 |
1998年 | 65篇 |
1997年 | 61篇 |
1996年 | 53篇 |
1995年 | 53篇 |
1994年 | 44篇 |
1993年 | 61篇 |
1992年 | 55篇 |
1990年 | 46篇 |
1989年 | 57篇 |
1988年 | 45篇 |
1987年 | 52篇 |
1986年 | 48篇 |
1985年 | 54篇 |
1984年 | 53篇 |
1983年 | 77篇 |
1982年 | 58篇 |
1981年 | 54篇 |
1980年 | 57篇 |
1979年 | 54篇 |
1978年 | 61篇 |
1977年 | 64篇 |
1976年 | 51篇 |
1975年 | 52篇 |
1974年 | 43篇 |
1973年 | 47篇 |
1972年 | 42篇 |
1971年 | 42篇 |
1969年 | 40篇 |
排序方式: 共有5858条查询结果,搜索用时 15 毫秒
121.
122.
123.
Pedro Pérez Herrero 《Colonial Latin American Review》1995,4(1):217-232
Tráfico de Indias y política oceánica. By Fernando Bordejé Y Morencos. Madrid: MAPFRE, 1992. Pp. 341.
Relaciones económicas entre España y América hasta la independencia. By John R. Fisher. Madrid: MAPFRE, 1992. Pp. 280.
Las comunicaciones en América. By Secundino‐José Gutiérrez Alvarez. Madrid: MAPFRE, 1993. Pp. 424.
Piratas, bucaneros, filibusteros y corsarios en América. Perros, mendigos y otros malditos del mar. By Manuel Lucena Salmoral. Madrid: MAPFRE, 1992. Pp. 306.
El dinero americano y la política del imperio. By María Emelina Martín Acosta. Madrid: MAPFRE, 1992. Pp. 333.
Cargadores a Indias. By Julian B. Ruiz Rivera and Manuela Cristina García Bernal. Madrid: Mapfre, 1992. Pp. 395. 相似文献
124.
Morphological Impacts and Implications of a Trial Release on the Wingecarribee River,New South Wales
A trial, monitored release on the Wingecarribee River over 27 days had a peak discharge below the Wingecarribee Dam of 1090 ML/d, which had a flow duration of 0.95 per cent. Morphological impacts on 29 km of channel below the dam included bank erosion, concentrated neck overflow, bed degradation and channel widening at recent cutoffs, sedimentation in weir pools and overbank flow, particularly at discharges greater than 800 ML/d. Prolonged operational releases at bankfull discharge (400–800 ML/d) will have the greatest morphologic impacts and should be avoided. Pulses which dissipate stream power over a broad, well-vegetated floodplain should be incorporated in the operational release policy, provided such pulses are phased to facilitate channel and vegetation recovery. 相似文献
125.
There is increasing concern about environmental impacts of acidic drainage from acid sulphate soils on Holocene estuarine flood plains. Acidity derives from oxidation of iron pyrite in the sediments. Natural factors determine concentrations and distributions of pyrite accumulations, but human activities have reduced pyrite accumulation in the Pearl River Delta with land use practices increasing terrestrial sediment discharge. Large freshwater discharges and management techniques have enabled sustainable use of these soils. High concentrations of pyrite occur in many estuarine flood plains of Australia because of relatively greater marine inputs. Drainage of these soils enhances pyrite oxidation and estuarine acidification, which is associated with fish-kills. For sustainable development, the problems of acid sulphate soil drainage must be recognised and overcome. 相似文献
126.
127.
128.
C. F. W. Higham 《International Journal of Historical Archaeology》1998,2(3):235-260
The Early Historic Period in the Mun Valley occupies a critical three centuries, from A.D. 500 to A.D. 800, a period often known as that of Zhenla, a name derived from early Chinese accounts. This article first describes early findings of fieldwork designed to illuminate the prehistory of the upper Mun Valley, a period which covers approximately two millennia, with initial settlement now dated between 1500 and 1000 B.C. It then considers the nature of the transition to the complex polities of Zhenla. This involves a combination of archaeological and documentary evidence. Sources for the latter are rare for the Mun Valley, but by broadening the area considered, it is possible to integrate archaeological and historical sources in order to portray the intensifying social changes which characterize the Early Historic Period. It is suggested that most of the Mun Valley was occupied by Khmer speakers during the Iron Age, people responsible for the transition to increasingly centralized polities of the Early Historic Period. In the upper reaches of the Mun catchment, and in the Chi Valley to the north, the late prehistoric inhabitants spoke Mon. They had close affinities with the Dvaravati polities of Central Thailand. If confirmed, this hypothesis would indicate a series of local trends towards increasing social complexity which we can recognize in the early epigraphic record. 相似文献
129.
130.
Cultural resource management (CRM) work accounts for most of the archaeology conducted in the United States. A diverse and
somewhat fragmented field, CRM has nonetheless achieved a degree of institutional and organizational maturity. CRM archaeology
has produced important contributions to archaeological methodology and has established and refined knowledge of regional cultural-historical
sequences and settlement and subsistence patterns. The current florescence of historical archaeology is attributable to CRM.
Yet the maintenance of high quality in CRM is a pervasive and enduring problem. Academic institutions need to reestablish
alliances with the CRM community. The future viability of CRM archaeology depends on factors both internal and external to
the discipline: regulatory and statutory “reform,” agency funding levels, looting and other destructive forces, and Native
American and other public involvement. 相似文献