首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   308篇
  免费   16篇
  324篇
  2024年   1篇
  2023年   7篇
  2022年   1篇
  2021年   1篇
  2020年   12篇
  2019年   8篇
  2018年   21篇
  2017年   37篇
  2016年   14篇
  2015年   15篇
  2014年   24篇
  2013年   74篇
  2012年   16篇
  2011年   12篇
  2010年   5篇
  2009年   14篇
  2008年   14篇
  2007年   8篇
  2006年   2篇
  2005年   5篇
  2004年   7篇
  2003年   3篇
  2002年   1篇
  2000年   1篇
  1999年   4篇
  1998年   1篇
  1997年   3篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1987年   3篇
  1986年   1篇
  1982年   1篇
  1981年   1篇
  1971年   1篇
  1970年   1篇
排序方式: 共有324条查询结果,搜索用时 15 毫秒
91.
Iran's scientific impact has suffered hard from decades of imposed and self‐elected isolation from Western influences and international collaboration. Lately, however, the world has witnessed a remarkable increase in scientific publications from Iranian scientists in fields like nanotechnology; material science; and, perhaps most pronounced, chemistry. In this article, the factors behind this “publication boom” are discussed and examined together with an analysis of the coherence between the country's long‐term research strategies and short‐term needs in relation to present organic chemical research conducted at various Iranian universities and institutes. Organic chemistry is a keystone in important Iranian industrial sectors like the petroleum and agricultural industries, and also in the growing field of life science and pharmacology. The development of the petroleum industry and further refinement of raw oil into value‐added fine chemicals holds a key position in the reinforcement of the Iranian economy and labor market, thus motivating a governmental investment in chemical science and research. Taking an approach to find a reasonable balance with the impact from Western and Far Eastern scientific communities, Iran's own scientific roots and Islamic ideology could well be the success factor in becoming a worthy player on the international scientific arena.  相似文献   
92.
Abstract. This research was conducted in 1993–4 in several peripheral kolkhoz villages in the north-west Belarus Grodno province, a religious (Catholic/Orthodox) and linguistic (Belarussian/RussiadPolish/Lithuanian)borderland. The members of the folk communities of this region conceive and categorise social reality differently than it is done by the members of a nationalised and urbanised society, according to religious, and not nation-state, criteria. People are divided by these criteria into natsyas, i.e. religious groups. There are two main natsyas: the Catholics (also called Poles) and the Orthodox (called Rus' or Belarussians). The distinctive criterion for several natsyus is the language of a prayer: the Catholics pray in Polish and/or Lithuanian, the Orthodox in Old Church Slavonic and Russian. The terms Catholic natsya and Polish natsya (and similarly Orthodox natsya or Rus' natsya) are synonymous. The language of everyday speech does not differentiate the natsyas; all the villagers speak Belarussian dialect or so called ‘plain language’. The natsya, a concept specific of traditional folk societies, should not be confused with a ‘nation’, a political term of the modem world. None the less, the kolkhoz peasants of the region under study are confronted with a concept of ‘nation’. It results in a turmoil in their worldview and in confusion about their identity; what we see in the Belarussian villages is a process of change. The borderland where the material was collected seems an excellent field for the study of the process of the emergence of nations.  相似文献   
93.
94.
Explaining the emergence of status inequality in human societies is an important priority for many anthropological archaeologists, particularly those whose research includes intermediate scale societies (complex hunter–gatherers and early agriculturalists). Yet, fine grained records of emergent inequality are still exceedingly rare. This paper outlines a fine-grained record of cultural change from the Keatley Creek site, a complex hunter–gatherer village in British Columbia, in which it is possible to recognize the emergence of inequality and its demographic and economic correlates. Results of the study suggest that status inequality emerged abruptly after an extended period of socio-economic stability in the village under conditions of adversely altered resource conditions, demographic packing, and subsistence resource diversification and extensification.  相似文献   
95.
There is an ever-greater popular attachment to the commemoration of Anzac Day in Australia, with growing commercial, popular and institutional support around the country. This resurgence has also generated significant disagreement among historians, shaping the historiography of Anzac in recent years and raising important questions about Australia’s current obsession with Anzac: is it a reflection of increasing popular historical engagement, or an ideologically driven ‘mobilisation’ of the past? While various scholars have sought to unpack and understand this potent phenomenon of national sentiment, this article, based on a series of oral interviews with ordinary Australians in selected communities, reveals an uncertainty and complexity in many vernacular responses to Anzac that need to be included if that commemorative sentiment is to be properly understood.  相似文献   
96.
Il Politecnico (1945–47) is the most relevant Italian cultural journal in the immediate aftermath of WWII. It is also the most anomalous; the systematic integration in its graphic layout of textual and visual elements made it more similar to the illustrated magazines of the time than to other cultural journals. The choice to present highbrow contents in a graphic layout associated with popular mass media served to complicate the already tricky relationship between the editor – the writer Elio Vittorini – and the intellectuals working in the cultural agencies planning the journal: the Italian Communist Party and the publishing house Einaudi. A reconstruction of the intellectual network surrounding Il Politecnico and of how it began shrinking during the months of its lifespan shows how this conflict developed and finally led to its closure.  相似文献   
97.
Las Vegas experienced improvements in math and reading performance between 2006 and 2011. This study evaluates the benefits of these nonmarginal improvements to Las Vegas area homeowners, using a residential sorting model. We estimate households’ preferences for multiple characteristics including the proportion of proficient students in their assigned elementary school. The estimation accounts for the endogeneity of school quality using school boundary fixed effects. The welfare estimates suggest that the school quality improvements provided substantial benefits to the area's households. We find that benefit measures derived from a hedonic price model are substantially larger than our sorting model benefit measures.  相似文献   
98.
James Mill's History of British India’ (1817) played a major role in re-shaping the English policy and attitudes in India throughout the nineteenth century. This article questions the widely held view that the ‘HBI’ heralded the utilitarian justification of colonisation found for instance in John Stuart Mill's writings. It suggests that James Mill's role as a proponent of ‘utilitarian imperialism’ has been overstated, and argues that much of Mill's criticism of Indian society arose from the continuing influence of his religious education as well as from his links with a network of Presbyterian and Evangelical thinkers. It is only after his death that the colonialist views put forward in the History of British India were re-interpreted in light of his later attachment to utilitarianism.  相似文献   
99.
How did traditional farming transform the natural environment in the Hawaiian Islands? This question is one that has largely been addressed for rainfed farming of crops like sweet potato (Ipomoea batatas), but evidence is lacking for irrigated farming of the critical staple crop taro (Colocasia esculenta). We describe the results of soil nutrient and sedimentological analyses of deeply-stratified pondfield deposits representing a 600-year-long record of irrigated taro farming in the North Kohala District, Hawai‘i Island. Soil is categorized by particle size to determine modes of transport and deposition, and concurrent soil nutrient analyses were conducted to infer shifts in the source of sediments and changes associated with taro harvesting. The advent of farming is clearly detectable in sedimentology, the presence of charcoal found within sediments, and soil chemistry. However, diminished nutrient concentrations can be attributed largely to deposition of a mixture of upstream sediments. Overall, there is no clear evidence for nutrient draw-down by taro harvesting, but we cannot yet rule it out as a factor. This study demonstrates the inherent difficulty of correlating changes in soil nutrients evident in irrigated pondfields with the long term history of soil nutrient cycling.  相似文献   
100.
This study explores the interrelationship between the genus Canis and hunter–gatherers through a case study of prehistoric Native Americans in the San Francisco Bay-Sacramento Delta area. A distinctive aspect of the region's prehistoric record is the interment of canids, variously classified as coyotes, dogs, and wolves. Since these species are difficult to distinguish based solely on morphology, ancient DNA analysis was employed to distinguish species. The DNA study results, the first on canids from archaeological sites in California, are entirely represented by domesticated dogs (including both interments and disarticulated samples from midden deposits). These results, buttressed by stable isotope analyses, provide new insight into the complex interrelationship between humans and canids in both ritual and prosaic contexts, and reveal a more prominent role for dogs than previously envisioned.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号