全文获取类型
收费全文 | 258篇 |
免费 | 19篇 |
专业分类
各国政治 | 13篇 |
工人农民 | 15篇 |
世界政治 | 19篇 |
外交国际关系 | 21篇 |
法律 | 104篇 |
中国政治 | 11篇 |
政治理论 | 91篇 |
综合类 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 17篇 |
2017年 | 16篇 |
2016年 | 20篇 |
2015年 | 18篇 |
2014年 | 9篇 |
2013年 | 37篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 2篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有277条查询结果,搜索用时 15 毫秒
171.
Aaron F. Brantly 《Intelligence & National Security》2016,31(5):674-685
AbstractAppearances in cyberspace are deceptive and problematic. Deception in the cyber domain poses an immensely difficult challenge for states to differentiate between espionage activities in cyberspace and cyber attacks. The inability to distinguish between cyber activities places US cyber infrastructure in a perilous position and increases the possibility of a disproportionate or inadequate response to cyber incidents. This paper uses case analysis to examine the characteristics associated with the tools and decisions related to cyber espionage and cyber attacks to develop a framework for distinction leveraging epidemiological models for combating disease. 相似文献
172.
Michelle M. Jonika B.Sc. Carl E. Hjelmen Ph.D. Ashleigh M. Faris Ph.D. Alexander S. McGuane B.Sc. Aaron M. Tarone Ph.D. 《Journal of forensic sciences》2020,65(5):1579-1587
Blow flies (Calliphoridae) are important medically and economically and are commonly used in forensics as temporal markers in death investigations. While phenotypic traits in adult flies can be sexually dimorphic, sex identification in immatures is difficult. Consequently, little is known about how sex may result in developmental disparities among sexes even though there are indications that they may be important in some instances. Since genetic mechanisms for sex are well studied in model flies and species of agricultural and medical importance, we exploit the sex-specifically spliced genes transformer (tra) and doublesex (dsx) in the sex determination pathway to optimize a sex identification assay for immatures. Using known primer sets for tra and with a novel one for dsx, we develop PCR assays for identifying sex in four forensically relevant Calliphoridae species: Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), Cochliomyia macellaria (Fabricius), and Chrysomya rufifacies (Macquart) and evaluated their performance. Band detection rates were found to range from 71 to 100%, call rates ranged from 90 to 100%, and no error was found when bands could be called. Such information is informative for purposes of testimony and in preparation for development studies. The developed assays will assist in further differentiating sexually dimorphic differences in development of the Calliphoridae and aid in more accurately estimating insect age when age predictive markers (size, development time, molecular expression) are sexually dimorphic. 相似文献
173.
Aaron Metzger Lauren M. Alvis Benjamin Oosterhoff Elizabeth Babskie Amy Syvertsen Laura Wray-Lake 《Journal of youth and adolescence》2018,47(8):1663-1683
Civic developmental theory anticipates connections between normative developmental competencies and civic engagement, but little previous research has directly studied such links. The current study sought to contribute to civic development theory by examining associations between emotional and sociocognitive competencies (empathy, emotion regulation, prosocial moral reasoning, future-orientation) and civic engagement (volunteering, informal helping, political behaviors and beliefs, environmental behaviors, social responsibility values, civic skills). Data came from a geographically and racially diverse sample of 2467 youth (Mage?=?13.4, Range: 8–20 years, 56% female). The results indicated that empathy and future-orientation significantly predicted nearly all forms of civic engagement, whereas emotion regulation and prosocial moral reasoning were uniquely associated with specific forms of civic engagement. Exploratory multi-group models indicated that empathy and emotion regulation were more strongly associated with civic engagement among younger youth and prosocial moral reasoning and future-orientation were more strongly related to civic engagement among older youth. The findings help to advance developmental theory of youth civic engagement. 相似文献
174.
175.
176.
Horn AS 《Journal of youth and adolescence》2012,41(7):948-968
Community service is widely regarded as a fundamental experience in preparation for good citizenship, but it remains unclear whether common variants of service are consequential for civic outcomes. This study examines changes in the relative importance assigned to prosocial and egoistic values associated with service through different types of organizations, service prompted by external contingencies, and service that spans a narrow or wide frame of time. Data were drawn from the survey responses of 16,749 secondary school students (50 percent female, 28 percent ethnic minority, modal age = 15) who participated in the National Educational Longitudinal Study during their sophomore year in 1990 and completed a follow-up survey during their senior year in 1992. Results from a propensity score analysis indicated that service through humanitarian organizations but not other types of organizations was positively associated with the adoption of a prosocial value orientation. Service prompted by an institutional mandate or social pressure was negatively associated with prosociality relative to service characterized as strictly voluntary, although all students except those with an initially egoistic value orientation benefited from mandatory service relative to no service. While short-term service during the sophomore year had no enduring effect, long-term service predicted gains in prosociality above and beyond the effect of concurrent service. The findings suggest that the relationship between community service and prosocial value development can be optimized to the extent that service through a humanitarian organization is prompted by autonomy-supportive conditions over the course of 2 years. 相似文献
177.
Children of incarcerated parents are exposed to factors that place them at risk for delinquency. Few studies have examined
the effects of having an incarcerated parent after controlling for other experiences such as contextual risk factors and family
processes. Past studies have also not examined effects of recent, but not current, parental incarceration on children. The
present study examines an archival dataset, in which children aged 10–14 years and their parents/guardians reported children’s
risk experiences (e.g., exposure to poverty, parental substance use), family processes (e.g., level of family victimization,
family conflict), and children’s delinquent behaviors at two time points. Parents also reported their recent and past incarceration
history. Hierarchical linear regression analyses show that a history of parental incarceration predicted family victimization,
delinquent behaviors of children’s older siblings, and delinquent behaviors of the child participants, over and above children’s
demographic characteristics and other risk experiences. Recent parental incarceration predicted family conflict, family victimization,
and parent-reports of children’s delinquency after also controlling for previous parental incarceration. The role of family
processes in research and intervention directions involving children of incarcerated parents is discussed. 相似文献
178.
L. Christian Elledge Anne Williford Aaron J. Boulton Kathryn J. DePaolis Todd D. Little Christina Salmivalli 《Journal of youth and adolescence》2013,42(5):698-710
Electronic social communication has provided a new context for children to bully and harass their peers and it is clear that cyberbullying is a growing public health concern in the US and abroad. The present study examined individual and contextual predictors of cyberbullying in a sample of 16, 634 students in grades 3–5 and 7–8. Data were obtained from a large cluster-randomized trial of the KiVa antibullying program that occurred in Finland between 2007 and 2009. Students completed measures at pre-intervention assessing provictim attitudes (defined as children’s beliefs that bullying is unacceptable, victims are acceptable, and defending victims is valued), perceptions of teachers’ ability to intervene in bullying, and cyberbullying behavior. Students with higher scores on provictim attitudes reported lower frequencies of cyberbullying. This relationship was true for individual provictim attitudes as well as the collective attitudes of students within classrooms. Teachers’ ability to intervene assessed at the classroom level was a unique, positive predictor of cyberbullying. Classrooms in which students collectively considered their teacher as capable of intervening to stop bullying had higher mean levels of cyberbullying frequency. Our findings suggest that cyberbullying and other indirect or covert forms of bullying may be more prevalent in classrooms where students collectively perceive their teacher’s ability to intervene in bullying as high. We found no evidence that individual or contextual effects were conditional on age or gender. Implications for research and practice are discussed. 相似文献
179.
Aaron Ansell 《The Journal of peasant studies》2015,42(6):1263-1282
This paper explores the Workers’ Party government's attempt to use anti-poverty policy to disrupt rural patronage, and the implications of this effort for theories of patronage. I argue that state officials and race-based activists implementing President Lula's flagship ‘Zero Hunger Program’ (2003–2005) turned mundane program exercises into pilgrimage rites in an effort to build lateral solidarities among Afro-Brazilians and undermine their vertical patronage alliances. The partial success of such efforts suggests that there are circumstances in which vertical and horizontal alliances are compatible, and that investigating this compatibility entails consideration of local categories of exchange. 相似文献
180.
Do citizens turnout to vote because of changes in their personal financial situation or are they influenced by the nation’s economic performance? Previous research on this question is far from united. We attempt to unify the disparate literature on the effects of pocketbook and sociotropic evaluations on voter turnout in midterm and presidential elections. Our analysis of ANES data from 1978 to 2004, based on a reference-dependent model of voter turnout, indicates that both pocketbook and sociotropic considerations affect individuals’ decision of whether to vote in midterm elections. Those who perceive that over the last year their own financial situation has improved relative to the economy are less likely to vote than those who view the economy as outperforming their own financial situation. 相似文献