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   25010篇
  免费   518篇
各国政治   931篇
工人农民   1618篇
世界政治   1630篇
外交国际关系   858篇
法律   14706篇
中国共产党   2篇
中国政治   77篇
政治理论   5531篇
综合类   175篇
  2020年   213篇
  2019年   256篇
  2018年   1542篇
  2017年   1510篇
  2016年   1377篇
  2015年   343篇
  2014年   348篇
  2013年   1731篇
  2012年   578篇
  2011年   1286篇
  2010年   1288篇
  2009年   915篇
  2008年   1130篇
  2007年   1112篇
  2006年   457篇
  2005年   452篇
  2004年   558篇
  2003年   560篇
  2002年   410篇
  2001年   680篇
  2000年   628篇
  1999年   508篇
  1998年   297篇
  1997年   254篇
  1996年   223篇
  1995年   231篇
  1994年   269篇
  1993年   222篇
  1992年   342篇
  1991年   371篇
  1990年   333篇
  1989年   349篇
  1988年   316篇
  1987年   336篇
  1986年   340篇
  1985年   344篇
  1984年   297篇
  1983年   329篇
  1982年   265篇
  1981年   242篇
  1980年   181篇
  1979年   254篇
  1978年   172篇
  1977年   157篇
  1976年   132篇
  1975年   122篇
  1974年   138篇
  1973年   124篇
  1972年   114篇
  1971年   94篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
932.
Lorraine Benson's body was found beaten and strangled at Raynes Park, Surrey, in December 1988. Considering the possibility of linked offences, a murder squad was set up to work alongside a team already investigating a rape series in the Kingston area. A man's handkerchief left at a site a quarter of a mile from the murder scene was found to be stained with blood and saliva matching that of the victim. A DNA profile was obtained from a stain of nasal mucus on this handkerchief and found to match a suspect later arrested for an attempted rape in the same locality. Also of forensic interest were dust marks made by the zips of the victim's and defendant's coats and identification of the rope used for strangulation.  相似文献   
933.
Although media exposure has been related to cognitive preoccupation with appearance, research rarely investigated adolescents’ behavioral self-sexualization. To address this gap, the present study among 12- to 16-year-olds (N?=?1527; 50.2% girls) in Austria, Belgium, Spain, and South-Korea (1) investigates whether different types of media use relate to self-sexualization, (2) explores the explanatory value of rewarded appearance ideals, and (3) considers culture and gender as moderating factors. Despite cultural variation, a general trend of increasing self-sexualization with social media use and magazine reading appeared across the countries. Moreover, women’s magazine reading and rewards were related to self-sexualization among all the girls across the countries, which suggests that girls may be more vulnerable to the examined effects. Overall, this study provides a better understanding of the unique contribution of specific media genres to youth’s self-sexualization and points at the importance of social media use in girls’ and boys’ engagement in sexualizing appearance behaviors across four countries.  相似文献   
934.
Getting along with peers becomes increasingly important to health and well-being during early adolescence (10–14 years). Young adolescents may succeed with peers when they are well-liked by and popular among the larger peer group (or at the group-level of social complexity). They might also fare well with peers when they are able to form numerous mutual and high quality friendships (at the dyadic-level of social complexity). Theory emphasizes the interrelatedness of different types of peer experiences, but few longitudinal studies have examined the interplay among and between group- and dyadic-level peer experiences in the same study. As a result, it is not known whether group-level peer experiences are predictors of dyadic-level peer experiences, and/or vice versa. To address this limitation, this study examined the prospective and reciprocal relations between four indices of peer experiences, preference (or being highly liked and not disliked by peers), popularity (or having a reputation as popular), friendship quantity (or having many mutual friends), and friendship or relationship quality, during early adolescence. Participants were 271 adolescents (49% girls; Mage?=?11.52 years) who completed peer nominations of preference and popularity, a self-report measure of friendship quality, and nominated friends at two waves (Wave 1: November, Grade 6; Wave 2: October, Grade 7). Structural equation modeling indicated that friendship quantity predicted increases in preference and popularity and that friendship quality predicted increases in friendship quantity. Initial popularity was associated with decreases in preference. The importance of these findings for future research is discussed along with study limitations.  相似文献   
935.
Disordered eating is highly prevalent during adolescence and has a detrimental effect on further development. Effective prevention programs are needed to prevent unhealthy developmental trajectories. This study evaluated the efficacy of the POPS-program (POtsdam Prevention at Schools), a universal school-based eating disorder prevention program for adolescents. In a cluster-randomized design, we compared the intervention group receiving the prevention program to a waiting control group. Outcomes included indicators of disordered eating and relevant risk factors for eating disorders (body dissatisfaction, internalization of the thin ideal, perceived media pressure, perfectionism, emotional element of exercise, social comparison, and perceived teasing). Questionnaires were administered at the start of the intervention, 3 and 12 months post intervention. At baseline, 1112 adolescents aged 10 to 16 years participated (49% girls; 51% intervention group). Intention-to-treat analyses with the complete data set and per-protocol analyses as a completer analysis were performed. The intervention group showed a more favorable course compared to the control group regarding all observed risk factors for eating disorders except for perceived teasing. Effect sizes were small but comparable to other primary prevention programs. At 1-year follow-up, a small but significant effect on disordered eating was observed. Results of the per-protocol analyses were mostly confirmed by the intention-to-treat analyses. Results were promising for both genders although girls benefited more regarding disordered eating and internalization of the thin ideal. Further studies are warranted examining successful program elements and whether gender-specific programs are needed.  相似文献   
936.
937.
Adolescent romantic relationships have the potential to affect psychological functioning well into adulthood. This study assessed adolescent romantic relationship qualities as long-term predictors of psychological functioning utilizing a longitudinal multi-method, multi-informant study of 80 participants (59% female; 54% Caucasian, 35% African American, 11% mixed or other race) assessed at age 17 along with their romantic partners and at ages 25–27. Controlling for gender, family income, and baseline mental health, partner-reported hostile conflict at age 17 predicted relative increases in internalizing behaviors from age 17 to 27. In contrast, observed teen support with their partner during a help-seeking task at age 17 predicted relative decreases in externalizing behaviors over time. The results are interpreted as suggesting qualities that may help determine whether adolescent romances have positive vs. negative long-term psychological health implications.  相似文献   
938.
Adolescence and emerging adulthood are periods in life when individuals both question and define their place in society and form their identity. Meanwhile, active youth civic engagement represents a challenge for each democracy. The purpose of this study was to analyze the different forms of civic engagement among late adolescents and emerging adults and how they are related to personal identity and social identity, while adopting an integrative perspective through the lens of a person-oriented approach. The participants were 1217 (62.3% female) 16–24 year-old French students (M age ?=?19.17; SD age ?=?1.83). First, derived from cluster analyses, the findings emphasized diversity in civic engagement, from strong civic participation (in different formal and informal ways) to various forms of passivity. Diversity was also highlighted for personal identity and social identity profiles. Second, a Configural Frequency Analysis revealed a typical pattern associating passivity in civic engagement, personal carefree diffusion and rejection of social identity. Overall, these findings highlight an absence of general youth disaffection and provide a meaningful specific pattern for the understanding of passivity in political and civic matters in late adolescence and emerging adulthood.  相似文献   
939.
Research examining factors that predict youth’s involvement in organized activities is very limited, despite associations with positive outcomes. Using data from 1043 youth (49% female; 46.4% Hispanic, 35.4% African American, 14.0% Caucasian, and 4.2% other) from the Project on Human Development in Chicago Neighborhoods, this study examined how characteristics of parents (supervision, warmth) and neighborhoods (perceived neighborhood safety and collective efficacy) predict patterns of adolescents’ involvement in organized activities concurrently (i.e., intensity) and longitudinally (i.e., type and breadth). Parental supervision predicted adolescents’ participation in organized activities across multiple waves. Neighborhood violence was positively associated with concurrent participation in organized activities after controlling for socioeconomic status (SES), whereas higher neighborhood collective efficacy predicted greater breadth in organized activity participation across time. These findings have important implications regarding how to attract and sustain organized activity participation for low-income, urban youth.  相似文献   
940.
Sleep problems and emotion dysregulation are associated with depressive symptoms and alcohol use but little research has examined the long-term associations and the direction of effects between these factors. We examined these relationships with 1132 undergraduates (70.5% female) over 5 years. Sleep problems and emotion dysregulation, sleep problems and depressive symptoms, and emotion dysregulation and depressive symptoms were all related bidirectionally. Tests of indirect effects indicated that sleep problems predicted depressive symptoms over time (and vice versa) via emotion dysregulation and emotion dysregulation predicted depressive symptoms over time (and vice versa) via sleep problems. The results highlight the need to assess direction of effects, given that many factors that are typically seen as “predictors” also can be framed as “outcomes”.  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