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   860篇
  免费   53篇
各国政治   74篇
工人农民   89篇
世界政治   80篇
外交国际关系   47篇
法律   442篇
中国共产党   1篇
中国政治   6篇
政治理论   172篇
综合类   2篇
  2024年   1篇
  2023年   6篇
  2022年   4篇
  2021年   9篇
  2020年   30篇
  2019年   38篇
  2018年   51篇
  2017年   56篇
  2016年   56篇
  2015年   29篇
  2014年   49篇
  2013年   148篇
  2012年   31篇
  2011年   39篇
  2010年   34篇
  2009年   31篇
  2008年   28篇
  2007年   31篇
  2006年   23篇
  2005年   35篇
  2004年   25篇
  2003年   35篇
  2002年   27篇
  2001年   8篇
  2000年   8篇
  1999年   3篇
  1998年   7篇
  1997年   7篇
  1996年   9篇
  1995年   9篇
  1994年   3篇
  1993年   5篇
  1992年   3篇
  1991年   5篇
  1990年   2篇
  1989年   3篇
  1988年   2篇
  1987年   6篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1980年   2篇
  1979年   1篇
  1978年   2篇
  1976年   1篇
  1974年   1篇
  1972年   1篇
  1969年   1篇
  1967年   1篇
排序方式: 共有913条查询结果,搜索用时 16 毫秒
21.
22.
23.
Intravascular lymphoma (IVL) is a rare subtype of extranodal lymphomas that is characterized by the selective growth of neoplastic cells within the lumen of small vessels. Authors document the case of an unexpected death caused by an undiagnosed intravascular large B-cell lymphoma with multi-organ involvement, which had initially manifested as an infection and then as an unclarified central nervous system pathology. Histological examination showed a diffuse intravascular large B-cell brain lymphoma with prominent cerebral involvement. The relevance of the case report reveals the importance of an autopsy of an extremely rare and threatening pathology that in most cases is diagnosed only postmortem. As a result, the role of the forensic pathologist becomes particularly important. When specifically performing an in-depth autopsy evaluation with a specific histologic analysis, it is possible to identify the intravascular lymphoma and declare a more accurate cause of death.  相似文献   
24.
Many studies in the literature have highlighted the utility of virtual 3D databanks as a substitute for real skeletal collections and the important application of radiological records in personal identification. However, none have investigated the accuracy of virtual material compared to skeletal remains in nonmetric variant analysis using 3D models. The present study investigates the accuracy of 20 computed tomography (CT) 3D reconstruction models compared to the real crania, focusing on the quality of the reproduction of the real crania and the possibility to detect 29 dental/cranial morphological variations in 3D images. An interobserver analysis was performed to evaluate trait identification, number, position, and shape. Results demonstrate a false bone loss in 3D models in some cranial regions, specifically the maxillary and occipital bones in 85% and 20% of the samples. Additional analyses revealed several difficulties in the detection of cranial nonmetric traits in 3D models, resulting in incorrect identification in circa 70% of the traits. In particular, pitfalls included the detection of erroneous position, error in presence/absence rates, in number, and in shape. The lowest percentages of correct evaluations were found in traits localized in the lateral side of the cranium and for the infraorbital suture, mastoid foramen, and crenulation. The present study highlights important pitfalls in CT scan when compared with the real crania for nonmetric analysis. This may have crucial consequences in cases where 3D databanks are used as a source of reference population data for nonmetric traits and pathologies and during bone-CT comparisons for identification purposes.  相似文献   
25.
26.
The article seeks to reassess the traditional stereotype of the complex Balkan family, especially in Bulgaria, on the basis of published and unpublished materials. On most measure features, such as population structure, marriage patterns, fertility and mortality rates, family and household size and structure, and inheritance patterns the Balkans show a great deal of variety and, on some measures, are more like the western and central parts of Europe than the easter-part. But all attempts to argue for the historical predominance of the zadruga in southeastern Europe (and in Bulgaria in particular) are presumptious, because the zadruga has been firmly documented only for the period from the late eighteenth to the early twentieth century, when it was not statistically predominant. Its appearance (or recurrence) and decline could be explained by different factors, and almost promising area of exploration seems to be the possible connection between a stockbreeding economy and multiple families of the zadruga type.  相似文献   
27.
Abstract

We study the degree of convergence or divergence in fiscal decentralization in the European Union over the period 1995–2015 using a club convergence approach. First, we analyze non-central expenditure and revenue as percentages of GDP, of total expenditure and of total revenue. The results for the EU-15 countries indicate some clustering, with three clubs formed when using GDP and four to five when using total revenue or expenditure. Second, we study the gap between expenditure and revenue as a proxy of fiscal responsibility. This results in three and two clubs respectively, with Denmark as the divergent country with the highest gap. Finally, we analyze potential unions of clubs and transitions. We also interpret our results taking into account variables found in the literature as determinants of fiscal decentralization. These results show how European countries are quite heterogeneous in terms of fiscal federalism and decentralization, with greater convergence in fiscal responsibility than in the other magnitudes.  相似文献   
28.
Advertisers shy away from using non-traditional (vs. traditional) male gender portrayals even though theory suggests they may be more effective cross-nationally. Two main hypotheses were tested cross-nationally for the first time. H1: ‘paternalistic’ male stereotypes (e.g. Househusband) would be more effective than ‘envious’ male stereotypes (e.g. Businessman) across countries confirming the stereotype content model (SCM). H2: the match between initial male gender role attitudes and advertisement type would increase advertisement effectiveness only in countries with relatively low egalitarian norms (i.e. Poland and South Africa). A cross-national study was conducted through the use of student samples following a 3(country: United Kingdom, Poland and South Africa) × 2(advertisement type) × (gender attitude) mixed design (N = 373). A three-way multivariate analysis of variance showed support for H1 and partial support for H2 (i.e. the second hypothesis held on purchase intent and for South Africa). The study provides evidence for the cross-national applicability of the SCM to advertising and the limited predictive value of gender attitudes for purchase intent depending on country. Thus, contrary to mainstream advertising practices, breaking male gender stereotypes does appear to pay cross-nationally. Theoretical and practical implications alongside the potential for change in practices are discussed.  相似文献   
29.
We estimate the effect of armed conflict on adolescents’ childbearing transition. Three types of models are estimated: models in origin, which determine the current effect of violence; context change models, which estimate the effect of decreased violence levels; and violence aftermath models, which indicate the groups that do not completely adapt to a peaceful context. Through multilevel logistic models, we find that the coefficient of violence depends on the municipality in where adolescents reside or resided. We conclude that violence promotes the transition to childbearing particularly among rural females. However, a reduction in violence levels reduces the probabilities of childbearing.  相似文献   
30.
Indigenous vegetables play an important role in Kenyan food security, but production is limited by poor seed quality. Traditionally, seeds have been traded through informal networks, but a new formal seed sector is emerging. This study assessed the relative potential for formal or informal seed systems to meet the need for high-quality indigenous vegetable seed. By evaluating determinants of farmers’ seed purchasing behaviour, we conclude that informal seed systems have greater potential to meet this need and should be strengthened. This study suggests that policy-makers should use context-specific data to guide decisions on seed policy.  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