全文获取类型
收费全文 | 1152篇 |
免费 | 19篇 |
专业分类
1171篇 |
出版年
2024年 | 10篇 |
2023年 | 14篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 31篇 |
2019年 | 34篇 |
2018年 | 29篇 |
2017年 | 41篇 |
2016年 | 33篇 |
2015年 | 27篇 |
2014年 | 33篇 |
2013年 | 157篇 |
2012年 | 46篇 |
2011年 | 55篇 |
2010年 | 78篇 |
2009年 | 78篇 |
2008年 | 52篇 |
2007年 | 67篇 |
2006年 | 51篇 |
2005年 | 45篇 |
2004年 | 25篇 |
2003年 | 40篇 |
2002年 | 37篇 |
2001年 | 32篇 |
2000年 | 26篇 |
1999年 | 20篇 |
1998年 | 11篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1171条查询结果,搜索用时 0 毫秒
991.
Although the development of punctuated equilibrium theory makes broad reference to the bureaucratic procedures that regulate budgetary decision making and makes reasonable assumptions about the influence of those procedures on the dynamic of resource allocation, little is known about how the specific mechanisms work. This has led to a call to understand the processes that cause friction in greater detail. This study examines how budgetary output patterns may be influenced by governments' strategic fiscal choices. Using an approach that highlights the roles of various fiscal policy-making processes, we found significant deviations of budgetary output patterns in capital projects, restricted funds, and entitlement spending, thus signifying the influence of fiscal practices on resource allocation decisions. We further examined how fiscal influences may be realized in the political process of democratization in Hong Kong. By examining legislative filibuster cases related to capital projects, we found evidence associating democratization with greater institutional friction and consequently with larger budgetary output punctuations. 相似文献
992.
Dawei Cai Zhuowei Tang Huixin Yu Lu Han Xiaoyan Ren Xingbo Zhao Hong Zhu Hui Zhou 《Journal of archaeological science》2011,38(4):896-902
China has a long history of sheep husbandry, and has several indigenous sheep breeds. However, the exact geographic origin of Chinese domestic sheep remains unclear. To provide valuable genetic information for origin of Chinese domestic sheep, we performed an ancient DNA study on 22 sheep excavated from four Bronze Age archaeological sites in Northern China. Two lineages (A and B) were observed in ancient Chinese sheep, of which lineage A was predominant reaching a frequency of 95.5%. Furthermore, phylogenetic network showed that the most frequent haplotype in ancient sheep was the founder of lineage A. These results suggest that Lineage A may hold the key to understanding the origin of Chinese domestic sheep. Sequence sharing and principal component analysis showed that the ancient Chinese sheep had a close affinity to modern Chinese sheep. However, there was no significant breed structure among three modern Chinese sheep groups, making it difficult to determine their relationship to ancient Chinese sheep. Lastly, our results imply that ancient DNA analysis could provide a new way to investigate prehistoric East-West contact. 相似文献
993.
994.
995.
996.
民国时期钨砂走私现象探析 总被引:2,自引:0,他引:2
钨砂走私作为一种特殊而又有重要影响的非法贸易行为,是民国时期走私问题研究的重要课题。钨砂走私现象伴随世界风云的急剧变幻与国民政府钨砂政策的变化,经历了民国时期的大部分岁月。与同时期其他走私现象相比,钨砂走私具有很大的特殊性,主要表现在:钨砂走私花样繁多;私钨的来源、去向与走私路线均有一定的规律性;国民政府的钨砂统制政策造成了钨砂走私的盛行;钨砂走私对中国有百害而无一利。钨砂走私研究对于多角度认识民国社会,乃至探求百年来中国的社会特征与政治行为,有一定的意义。 相似文献
997.
998.
Broomcorn and Foxtail millets were major crops in the Yellow River Valley region, Henan, China, during the Neolithic Yangshao period. Phytoliths and macro remains have been used to understand crop choices in this period. Distinguishing between phytoliths from millet crops and panicoid non cultigens can be challenging. We examine the effect of using only one or two identification criteria compared with a more stringent five or more with phytoliths from archaeological samples to examine crop ratios. We compare our results with the results from the macro remains. This demonstrates, firstly, that using more identification markers has a very definite effect on the results and secondly, phytoliths and macro remains are complementary proxies that when used together can produce more accurate results than used alone. 相似文献
999.
With the development of China’s economy, the protection and conservation of ancient buildings were put on the agenda. However, the current understandings on Chinese traditional mortars are limited and rarely reported in the literature. In this article, the authors investigate seven ancient city wall sites built during the Ming and Qing dynasties (1368–1841 AD) in situ, and subsequently the laboratory analysis were carried out on the collected mortar samples. The characterizations of mortar samples were performed using digital microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), simultaneous thermal analysis (TG-DSC), as well as wet chemical analysis. The analytical results show that pure lime mortar was widely used in construction during the Ming and Qing dynasties, and it was also a common practice adding sticky rice soup into slaked lime to form sticky-rice lime mortar during preparations. This organic-inorganic composite material could effectively improve mechanical strength of the lime mortar. Moreover, it was first found that the sticky-rice lime mortar sample from Kaifeng ancient city wall contained very fine quartz aggregates, with an approximate binder/aggregate ratio of 1:1. The appearance of this type of mortar probably indicates a great development of Chinese traditional mortars during the mid-19th century. 相似文献
1000.
Chung Min Lee 《Australian Journal of International Affairs》2003,57(2):281-307
Changing political attitudes in South Korea, and the appearance of some divergence of view between Washington and Seoul on the nature of the threat posed by North Korea are impelling a re-examination of the US-South Korea alliance. At the same time, although still concerned with deterring an invasion from Pyongyang, the alliance must now also deal with the possible conse quences of a catastrophic collapse of the North Korean state. Changing threat perceptions, developments in military technology and doctrine associated with the 'revolution in military affairs', as well as the emergence of new issues such as terrorism, all require a redefinition of the alliance. While the changing geo-strategic environment and the wider regional role of the alliance will all be factors in the modifications made to the Washington-Seoul security relationship, the key to South Korea's future alliance choices will be the nature of the path taken to eventual Korean unification. 相似文献