全文获取类型
收费全文 | 3776篇 |
免费 | 154篇 |
出版年
2023年 | 32篇 |
2021年 | 17篇 |
2020年 | 59篇 |
2019年 | 60篇 |
2018年 | 405篇 |
2017年 | 321篇 |
2016年 | 362篇 |
2015年 | 90篇 |
2014年 | 94篇 |
2013年 | 710篇 |
2012年 | 117篇 |
2011年 | 249篇 |
2010年 | 253篇 |
2009年 | 110篇 |
2008年 | 134篇 |
2007年 | 135篇 |
2006年 | 56篇 |
2005年 | 57篇 |
2004年 | 34篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 24篇 |
2000年 | 19篇 |
1999年 | 28篇 |
1998年 | 15篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 11篇 |
1993年 | 20篇 |
1992年 | 17篇 |
1991年 | 21篇 |
1989年 | 10篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 24篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 19篇 |
1982年 | 24篇 |
1981年 | 19篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1975年 | 15篇 |
1973年 | 11篇 |
1969年 | 11篇 |
1967年 | 15篇 |
排序方式: 共有3930条查询结果,搜索用时 15 毫秒
22.
23.
24.
25.
"Malthusians maintain that rapid population growth aggravates poverty, while Marxists contend that social formations determine its nature and extent. Each perspective is incomplete, however, since it ignores the insights of the other. Latin American states, characterized by dependent capitalism formations and dominated by ruling elites, are generally incapable of solving the problems of population and poverty. Since population growth under dependent capitalism weakens labor's bargaining position against capital, reduced population growth is emphasized as a labor empowerment strategy the poor can implement on their own to improve their socioeconomic conditions." 相似文献
26.
Archaeometric analysis of ceramic production in Tiwanaku state (c.500–1000 ce): An exploratory study
J. P. Ogalde A. Korpisaari C. Riera‐Soto B. Arriaza C. Paipa P. Leyton M. Campos‐Vallette N. Lara J. Chacama 《Archaeometry》2021,63(1):53-67
The chemical and mineralogical characterization of seven ceramic fragments produced within Tiwanaku state (c.500–1000 ce ) is reported. The instrumental techniques used included X‐ray elemental and mineralogical chemical analysis, Raman spectroscopy, and scanning and light microscopy. The results indicate there are several clay types, although they show similarities, such as the use of a plant‐based temper. The red colour of the decoration is hematite, and manganese oxides such as jacobsite are present in the black. The white colour is a mixture of gypsum and clay, and the orange is a mixture of hematite and clay. The use of colours, the quality of the clays and the temperatures reached during pottery firing point to expertise in ceramic production and to complex decision‐making processes. The multi‐elemental archaeometric approach documented here could become an important tool to shed a light on ancient ceramic technology and the internal variance of Tiwanaku pottery. 相似文献
27.
García-Heras Manuel Agua Fernando Madiquida Hilario Fernández Víctor M. de Torres Jorge Villegas María-Ángeles Ruiz-Gálvez Marisa 《African Archaeological Review》2021,38(2):297-318
African Archaeological Review - A set of beads made of glass, gastropod mollusk shell, and fishbone from a Swahili occupation level on Ibo Island (northern Mozambique) is dated to the eleventh and... 相似文献
28.
29.
Human bones from Late Eneolithic graves and Bronze Age settlement pits in Moravia (Czech Republic) were studied to reconstruct their post-mortem histories based on the distribution of their microbial destruction. Backscattered electrons in a scanning electron microscope (BSE-SEM) were used for visual assessment of bioerosion. Visual data from the histological analysis were transformed into quantitative data using the Waikato Environment for Knowledge Analysis (WEKA) toolkit. The results show that the presence of bioerosion is different between the two groups of samples. The bones from settlement pits display extensive bioerosion whereas the bones from graves display no or arrested bioerosion. The absence of bioerosion in graves is most probably linked with tomb burials of Corded Ware Culture. Given the tombs are frequently not preserved archaeologically, the state of bone bioerosion may serve as an indicator of their existence. 相似文献
30.
Darío Alejandro Ramirez María José Herrera-Soto Josefina González Andreu Francisca Santana-Sagredo Mauricio Uribe Rodríguez Rodrigo Nores 《Archaeometry》2023,65(5):1073-1089
Faunal remains from archeological sites worldwide, especially feces and regurgitated pellets, are usually subjected to paleoparasitological examination, allowing the identification of past animal parasites. In this study, we analyzed 10 samples of South American camelid dung, which played an important role for the ancient human groups in the South-Central Andes, dated between 341 and 1635 calCE, from the Iluga Túmulos site (Pampa del Tamarugal, Tarapacá region, Atacama Desert, Chile). Microscopy examination revealed parasite remains in seven samples, in which oocysts of Eimeria macusaniensis and eggs of Lamanema chavezi/Nematodirus lamae, Trichuris sp., Moniezia sp., capillariids, strongylids, and unidentified nematodes were found. Although some of these species pose a potential health risk to camelids, most are not considered to be of major zoonotic importance, which could explain the absence of these parasites on human coprolites from this site analyzed previously. This first paleoparasitological study on camelid fecal remains from northern Chile sheds light on the occurrence of gastrointestinal parasites and its relationship with Andean ancient human populations and the environment. 相似文献