全文获取类型
收费全文 | 3865篇 |
免费 | 79篇 |
专业分类
各国政治 | 178篇 |
工人农民 | 114篇 |
世界政治 | 194篇 |
外交国际关系 | 128篇 |
法律 | 2876篇 |
中国政治 | 19篇 |
政治理论 | 397篇 |
综合类 | 38篇 |
出版年
2021年 | 24篇 |
2020年 | 56篇 |
2019年 | 58篇 |
2018年 | 88篇 |
2017年 | 79篇 |
2016年 | 102篇 |
2015年 | 48篇 |
2014年 | 68篇 |
2013年 | 297篇 |
2012年 | 104篇 |
2011年 | 142篇 |
2010年 | 87篇 |
2009年 | 75篇 |
2008年 | 121篇 |
2007年 | 136篇 |
2006年 | 121篇 |
2005年 | 98篇 |
2004年 | 134篇 |
2003年 | 129篇 |
2002年 | 125篇 |
2001年 | 158篇 |
2000年 | 136篇 |
1999年 | 108篇 |
1998年 | 21篇 |
1993年 | 28篇 |
1992年 | 62篇 |
1991年 | 83篇 |
1990年 | 85篇 |
1989年 | 91篇 |
1988年 | 95篇 |
1987年 | 89篇 |
1986年 | 75篇 |
1985年 | 77篇 |
1984年 | 68篇 |
1983年 | 60篇 |
1982年 | 24篇 |
1981年 | 22篇 |
1979年 | 34篇 |
1978年 | 33篇 |
1977年 | 24篇 |
1976年 | 27篇 |
1975年 | 28篇 |
1974年 | 41篇 |
1973年 | 37篇 |
1972年 | 36篇 |
1971年 | 36篇 |
1970年 | 38篇 |
1969年 | 32篇 |
1968年 | 27篇 |
1967年 | 18篇 |
排序方式: 共有3944条查询结果,搜索用时 9 毫秒
101.
102.
103.
Document examiners sometimes eliminate writers on the basis of differences which are given too much weight. This article is an attempt to explain some conditions whereby differences in the writing of one individual are misinterpreted as significant differences, when they are actually caused by conditions which are unknown to the examiner. 相似文献
104.
A method for the routine profiling of illicit heroin samples received in casework has been developed which depends on simple and straightforward sample pretreatment, followed by gas chromatography on a capillary column using flame-ionization detection. The factors affecting the choice of each aspect of the procedure are discussed, as are the statistical data for sampling and the chromatography. Components of illicit heroin derived from opium and other adulterants have been identified. The significance of data from samples examined in 1986 is discussed. 相似文献
105.
Jason M. Newcomer Patti J. Clark Dixie K. Button Linda V. Weiland 《Journal of Gender Studies》2018,27(5):509-521
Certified aircraft mechanics represent the largest gender-based demographic disparity in aviation with a 49-to-1 male-to-female ratio. Recent research into women’s perspective on the aircraft mechanic career field revealed that a large majority of women felt unsure or negatively about their potential promotion opportunities and social acceptance. The purpose of this follow-on mixed-methods concurrent triangulation study was to explore the perspectives of men regarding the aforementioned topics to see if they differ from previously published research on women perceptions. A total of 587 men and 431 women completed an eight-question survey containing 5-point Likert-type and open-ended questions. The quantitative comparison consisted of the total 1018 responses, while only the survey responses from the 587 men were analysed for correlations and qualitative codes. Results indicated that there was a significant difference between the perceptions of men from those of the women regarding work environment safety and social acceptance. Additional correlation analysis revealed social acceptance to be a key variable when predicting career appropriateness, advancement opportunity and work environment safety. The 587 qualitative responses yielded results that differed from those of women, citing an assumption that women have the same advancement opportunities or be as socially accepted as men entering the field. 相似文献
106.
Christopher C. Weiss Brian V. Carolan E. Christine Baker-Smith 《Journal of youth and adolescence》2010,39(2):163-176
In an effort to increase both adolescents’ engagement with school and academic achievement, school districts across the United
States have created small high schools. However, despite the widespread adoption of size reduction reforms, relatively little
is known about the relationship between size, engagement and outcomes in high school. In response, this article employs a
composite measure of engagement that combines organizational, sociological, and psychological theories. We use this composite
measure with the most recent nationally-representative dataset of tenth graders, Educational Longitudinal Study: 2002, (N = 10,946, 46% female) to better assess a generalizable relationship among school engagement, mathematics achievement and
school size with specific focus on cohort size. Findings confirm these measures to be highly related to student engagement.
Furthermore, results derived from multilevel regression analysis indicate that, as with school size, moderately sized cohorts
or grade-level groups provide the greatest engagement advantage for all students and that there are potentially harmful changes
when cohorts grow beyond 400 students. However, it is important to note that each group size affects different students differently,
eliminating the ability to prescribe an ideal cohort or school size. 相似文献
107.
108.
Edmond P. Bowers Yibing Li Megan K. Kiely Aerika Brittian Jacqueline V. Lerner Richard M. Lerner 《Journal of youth and adolescence》2010,39(7):720-735
The understanding of positive development across adolescence rests on having a valid and equivalent measure of this construct across the breadth of this period of life. Does the Positive Youth Development (PYD) construct based on the Five Cs model have satisfactory psychometric properties for such longitudinal measurement invariance? Using longitudinal data derived from the 4-H Study of PYD, we assessed 920 youth (61.6% female) from a racially and ethically diverse sample (67.3% European American) who participated in three waves (Grades 8–10) of data collection. Building on prior findings that the Five Cs (i.e., Competence, Confidence, Connection, Character, and Caring) model of PYD was a robust measure that could be assessed comparably during early adolescence, we tested a hierarchy of second-order confirmatory factor analysis models to assess the extent to which PYD can be measured equivalently across middle adolescence. Evidence was found for strict measurement invariance across three measurement occasions, including equivalence of first-order and second-order factor loadings, equality of intercepts of observed variables, and equality of item uniqueness and disturbances of the first-order factors. These results suggest that PYD can be measured in the same way across measurement occasions, a prerequisite for the study of development. Implications for research and application of being able to measure PYD equivalently across adolescence are discussed. 相似文献
109.
Ellen H. O’Donnell Melissa Moreau Esteban V. Cardemil Alisha Pollastri 《Journal of youth and adolescence》2010,39(1):12-22
Research on the mechanisms by which interparental conflict (IPC) affects child depression suggests that both parenting and
children’s conflict appraisals play important roles, but few studies have explored the role of general cognitive style or
included both parenting and cognitions in the same design. Moreover, the effects of IPC on minority children are not well
understood. In this longitudinal study, parenting was examined as a mediator of the relation between increasing IPC and change
in depression. General cognitive style was included as a moderator. The combined influence of parenting and cognitions was
also explored. A racially and ethnically diverse sample of 88 fifth and sixth graders from two urban schools reported their
cognitive style, depressive symptoms, and perceptions of conflict and parenting at two time points separated by one year.
Parental warmth/rejection mediated the relation between IPC and depression, and general cognitive style acted as a moderator.
Parenting, cognitive style, and IPC did not significantly interact to predict change in depression over time. Findings indicate
that both parenting and children’s general cognitive style play a role in understanding the impact of increasing IPC on children’s
well-being. 相似文献
110.
This paper examines the federal government's success in implementing and providing high-quality service through e-government, something that has received very little attention. We define quality from the perspective of the end users of federal agency Web sites, as measured through customer survey data. Using data from the American Customer Satisfaction Index, we compare the performance of federal agency Web sites across a range of relevant variables with a private sector equivalent, e-business Web sites. Our findings suggest that federal e-government Web sites are not yet, in the aggregate, providing the same level of quality as their e-business counterparts. We also find significant variability among federal agencies. We discuss the implications of these findings for e-government performance measurement, performance benchmarking, and the market-centered theories of administrative reform that are driving e-government and similar transformations of government practice. 相似文献