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 46 毫秒
211.
This article explores the changing experiences and representation of Ireland's unmarried mothers from 1880 to 1973. It focuses on the stigma of illegitimacy in political and cultural discourse and the representation of unmarried mothers as immoral and their children as a drain on resources. These remained constant themes within the discourse of unmarried motherhood in Ireland throughout the nineteenth and twentieth centuries. The article uses the records of philanthropic, government and religious organisations to chart the rising interest in the moral reformation of unmarried mothers at the end of the nineteenth century and rising tolerance towards them by the end of the twentieth century.  相似文献   
212.
This article presents a systematic review and meta-analysis of the effectiveness of anti-bullying programs in schools. Studies were included if they evaluated the effects of an anti-bullying program by comparing an intervention group who received the program with a control group who did not. Four types of research design were included: a) randomized experiments, b) intervention-control comparisons with before-and-after measures of bullying, c) other intervention-control comparisons, and d) age-cohort designs. Both published and unpublished reports were included. All volumes of 35 journals from 1983 up to the end of May 2009 were hand-searched, as were 18 electronic databases. Reports in languages other than English were also included. A total of 622 reports concerned with bullying prevention were found, and 89 of these reports (describing 53 different program evaluations) were included in our review. Of the 53 different program evaluations, 44 provided data that permitted the calculation of an effect size for bullying or victimization. The meta-analysis of these 44 evaluations showed that, overall, school-based anti-bullying programs are effective: on average, bullying decreased by 20–23% and victimization decreased by 17–20%. Program elements and intervention components that were associated with a decrease in bullying and victimization were identified, based on feedback from researchers about the coding of 40 out of 44 programs. More intensive programs were more effective, as were programs including parent meetings, firm disciplinary methods, and improved playground supervision. Work with peers was associated with an increase in victimization. It is concluded that the time is ripe to mount a new program of research on the effectiveness of anti-bullying programs based on these findings.  相似文献   
213.
214.
Spectral analysis and ARMA models have been the most common weapons of choice for the detection of cycles in political time series. Controversies about cycles, however, tend to revolve around an issue that both techniques are badly equipped to address: the possibility of irregular cycles without fixed periodicity throughout the entire time series. This has led to two main consequences. On the one hand, proponents of cyclical theories have often dismissed established statistical techniques. On the other hand, proponents of established techniques have dismissed the possibility of cycles without fixed periodicity. Wavelets allow the detection of transient and coexisting cycles and structural breaks in periodicity. In this article, we present the tools of wavelet analysis and apply them to the study of two lingering puzzles in the political science literature: the existence of cycles in election returns in the United States and in the severity of major power wars.  相似文献   
215.
Using desorption/ionization techniques such as easy ambient sonic-spray ionization mass spectrometry (EASI-MS), it is possible to analyze documents of Brazilian vehicles for authenticity, providing a chemical profile directly from the surface of each document. A method for the detection of counterfeit documents is described, and the falsification procedure is elucidated. Forty authentic and counterfeit documents were analyzed by both positive and negative ion modes, EASI(±)-MS. EASI(+)-MS results identified the presence of (bis(2-ethylhexyl)phthalate plasticizer and of dihexadecyldimethylammonium biocide in both types of documents. For EASI(-)-MS results, the 4-octyloxybenzoic acid additive ([M + H](+): m/z 249) is present only in counterfeit documents. It was also found that counterfeit vehicle documents are produced via Laserjet printers. Desorption/ionization techniques, such as EASI-MS, offer therefore, an intelligent way to characterize the counterfeiting method.  相似文献   
216.
In developed countries, sudden infant death syndrome (SIDS) represents the most prevalent cause of death in children between 1 month and 1 year of age. SIDS is a diagnosis of exclusion, a negative autopsy which requires the absence of structural organ disease. Although investigators have confirmed that a significant percentage of SIDS cases are actually channelopathies, no data have been made available as to whether other sudden cardiac death-associated diseases, such as hypertrophic cardiomyopathy (HCM), could be responsible for some cases of SIDS. The presence of a genetic mutation in the sarcomeric protein usually affects the force of contraction of the myocyte, whose weakness is compensated with progressive hypertrophy and disarray. However, it is unclear whether in the most incipient forms, that is, first years of life, the lack of these phenotypes still confers a risk of arrhythmogenesis. The main goal of the present study is to wonder whether genetic defects in the sarcomeric proteins, previously associated with HCM, could be responsible for SIDS. We have analysed 286 SIDS cases for the most common genes implicated in HCM in adults. A total of 680 mutations localised in 16 genes were analysed by semi-automated matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF-MS) using the Sequenom MassARRAY(?) System. Ten subjects with completely normal hearts showed mutated alleles at nine of the genetic variants analysed, and one additional novel mutation was detected by conventional sequencing. Therefore, a genetic mutation associated with HCM may cause sudden cardiac death in the absence of an identifiable phenotype.  相似文献   
217.
Using co-citation analysis, the present study attempts to rationalize and organize the combined alliance and innovation literature in order to determine its intellectual structure (i.e. its shared attributes such as models, theories, methods, findings, and implications), as well as to gain a deeper understanding of the most important research trends. More specifically, our goals are: (1) to delineate the intellectual structure of research on alliance and innovation, as represented in the academic literature; (2) to determine the subfields that constitute the intellectual structure and the relationships, if any, between these subfields; (3) to identify contributions that play a pivotal role in bridging two or more conceptual domains of research; and finally, (4) to map the intellectual structure in a two-dimensional space in order to visualize spatial distances between intellectual themes. Implications for future studies are then drawn.  相似文献   
218.
219.

Objectives

The aim of this paper is to respond to the commentary of Peter K. Smith, Christina Salmivalli, and Helen Cowie (Journal of Experimental Criminology, 2012), who raise concerns regarding some of the findings of our systematic review and meta-analyses on the effectiveness of bullying prevention programs. They target three findings in particular: (1) the significant association of ??Work with Peers?? with greater victimization; (2) the significant association of ??Disciplinary Methods?? with less bullying perpetration and victimization; and (3) the age variations in effectiveness, suggesting larger effect sizes for older age students.

Methods

We provide explicit information and further detailed analyses on the relationship between these features and effect sizes, including heterogeneity tests and results from weighted regression analyses. For one element in particular (work with peers), we present further research findings from evaluations conducted by Smith, Salmivalli, and Cowie (and also findings from other independent researchers) which support our previous findings. New within-program analyses to examine variations in effect sizes with the age of the students are also presented.

Results

Evaluations conducted by Smith, Salmivalli and Cowie (and by other independent researchers) indicate the same research conclusions: although peer support schemes appear effective based on attitudinal surveys, these schemes are not related to actual levels of bullying or victimization and, in fact, are quite often related to an increase in bullying and victimization. Our definition of ??disciplinary methods?? did not include the zero-tolerance approach or any type of harsh discipline as suggested in the commentary. In all relevant cases, ??disciplinary methods?? included sanctions within a warm and loving framework, following the Olweus bullying prevention guidelines. While most programs that utilized firm disciplinary methods were inspired by Olweus, the relationship between disciplinary methods and less victimization was not driven by the Olweus program (which was not related to the victimization effect size). Larger effect sizes (i.e. reductions in bullying and victimization) for programs implemented with older students is a robust result also found in a more recent systematic review regarding the effects of anti-bullying programs on bystander intervention. In within-program analyses, most results suggested that effect sizes were greater for younger students, but these results were driven by the less controlled evaluations. The most controlled evaluation (randomized experiment) provided the opposite result.

Conclusions

More research is clearly needed on the effectiveness of bullying prevention programs with students of different ages, and we also recommend randomized experiments to assess the importance of different intervention components.  相似文献   
220.
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