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   30866篇
  免费   1451篇
  国内免费   5篇
各国政治   1310篇
工人农民   1412篇
世界政治   2138篇
外交国际关系   1038篇
法律   20260篇
中国共产党   8篇
中国政治   235篇
政治理论   5666篇
综合类   255篇
  2021年   158篇
  2020年   576篇
  2019年   633篇
  2018年   813篇
  2017年   884篇
  2016年   960篇
  2015年   709篇
  2014年   772篇
  2013年   3097篇
  2012年   843篇
  2011年   891篇
  2010年   814篇
  2009年   873篇
  2008年   917篇
  2007年   956篇
  2006年   938篇
  2005年   834篇
  2004年   813篇
  2003年   776篇
  2002年   750篇
  2001年   1160篇
  2000年   1016篇
  1999年   841篇
  1998年   446篇
  1997年   320篇
  1996年   367篇
  1995年   337篇
  1994年   341篇
  1993年   342篇
  1992年   554篇
  1991年   592篇
  1990年   567篇
  1989年   507篇
  1988年   559篇
  1987年   490篇
  1986年   577篇
  1985年   543篇
  1984年   429篇
  1983年   405篇
  1982年   332篇
  1981年   316篇
  1980年   251篇
  1979年   358篇
  1978年   221篇
  1977年   180篇
  1976年   163篇
  1975年   208篇
  1974年   233篇
  1973年   175篇
  1972年   170篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Abstract

Rural producer associations are considered a potential community-driven solution to the problems of smallholder agriculture. This article evaluates the impact of organising female farmers into producer associations in Gujarat, India. The initiative provided training, information, access to inputs, risk mitigation, and market linkages. Over 18 months, the programme weakly increased members’ non-farm income and access to output markets. It had stronger impacts on members’ awareness and utilisation of financial services. Impacts were heterogeneous, varying by pre-existing socioeconomic conditions. These findings suggest that producer associations can lower transaction costs for smallholders, but that poverty alleviation may be a longer-term prospect.  相似文献   
962.
This paper analyses a critical aspect of the internal functioning of five major Indian political parties, namely the nomination of candidates for parliamentary elections, focusing on the pattern of renomination of former candidates and incumbents. The data are analysed against the literature on the structure and functioning of Indian parties, and interview material on the process of nomination in the 2009 and 2004 elections. From the perspective of a six-fold typology of centralisation of nomination processes drawn from the comparative literature, it is found that all the parties analysed are in either the second-most centralised, or even most centralised categories, and that for the three major national parties, Congress, Bharatiya Janata Party and Communist Party of India (Marxist), past performance plays a role in nominations, the majority of incumbents being renominated in the post-1989 period.  相似文献   
963.
Abstract

We used survey and ethnographic data to study savings in a highly autarkic society of native Amazonians in Bolivia (Tsimane’). We equated savings with the amount of maize and rice in storage, area planted with plantains and manioc, and number of edible domesticated animals owned by a household or an adult. We found no large inter-annual change in savings possibly due to low income, impulsivity and a bundle of institutions and norms, such as borrowing, theft and reciprocity norms. The bundle attenuates the need for household formal savings at the periphery of markets.  相似文献   
964.
School engagement, or the extent to which students are involved in, attached and committed to the academic and social activities in school, plays a prominent role in preventing academic failure, promoting competence, and influencing a wide range of adolescent outcomes. Although the multidimensional nature of school engagement is well-recognized, how the three purported parts of the construct work together is largely unknown. By using data from the longitudinal, 4-H study of Positive Youth Development, involving a sample of 1,029 adolescents (67.7 % female; mean age at Grade 9 = 14.92 years; 74.4 % of participants were European American, 5.2 % were Latino/a, 7.3 % were African American), the current study examined the interrelationships of behavioral, emotional, and cognitive aspects of school engagement over three years in adolescence (Grades 9–11). We used autoregressive lagged effects models to assess the relationships among the three engagement constructs. Results indicated that behavioral and emotional engagement were related bidirectionally (each variable was a basis and an outcome of the other). In addition, behavioral engagement influenced cognitive engagement (but the reverse of this relation was not found). Implications for future research are discussed.  相似文献   
965.
The positive youth development perspective, a strength-based relational developmental systems model that focuses on mutually influential relationships between individuals and contexts, has been used to study thriving across the second decade of life. However, more attention has been paid empirically to identifying the features of the individual (e.g., intentional self regulation, hope, or purpose) or to enumerating the role of context-general ecological assets than to the nature of individual-context relationships linked to thriving within specific contexts. The goal of this special section is to provide initial research reports about context-specific instances of the thriving process. The research focuses on two contexts where many youth spend a considerable amount, and often the majority, of their time—school and out-of-school time sports activities.  相似文献   
966.
Identity-based conceptualizations of sexual orientation may not account adequately for variation in young women’s sexuality. Sexual minorities fare worse in psychosocial markers of wellbeing (i.e., depressive symptoms, anxiety, self esteem, social support) than heterosexual youth; however, it remains unclear whether these health disparities exclusively affect individuals who adopt a sexual minority identity or if they also may be present among heterosexually-identified youth who report same-sex attractions. We examined the relationship between sexual attraction, sexual identity, and psychosocial wellbeing in the female only subsample (weighted, n = 391) of a national sample of emerging adults (age 18–24). Women in this study rated on a scale from 1 (not at all) to 5 (extremely) their degree of sexual attraction to males and females, respectively. From these scores, women were divided into 4 groups (low female/low male attraction, low female/high male attraction, high female/low male attraction, or high female/high male attraction). We explored the relationship between experiences of attraction, reported sexual identity, and psychosocial outcomes using ordinary least squares regression. The results indicated sexual attraction to be predictive of women’s psychosocial wellbeing as much as or more than sexual identity measures. We discuss these findings in terms of the diversity found in young women’s sexuality, and how sexual minority status may be experienced by this group.  相似文献   
967.
As a time of notably increased stress and a marked rise in depressive symptoms, adolescence is a key period in which to examine how stress is related to mental health outcomes. Many studies examine stress as a unitary construct; however, research suggests that how adolescents respond to stress within different domains may differentially predict depression. The current study used an 8-week weekly diary design to assess how adolescents’ cognitive appraisals, rumination, and co-rumination in response to dependent, independent, social, and nonsocial stressors differentially predicted depressive symptoms. Participants were 111 high school students (72 % female) ages 14–19 years (mean age 16.4). Results indicated that rumination and co-rumination about dependent and social events, rather than independent or nonsocial events, prospectively predicted depressive symptoms. Negative cognitive appraisals prospectively predicted depressive symptoms regardless of domain. This study provides support for the hypothesis that adolescents’ responses to stress in different domains differentially predict depressive symptoms.  相似文献   
968.
This article identifies the arrest trajectories of youth from ages 12 through 24 years old and tests hypotheses derived from Moffitt’s developmental taxonomic theory of crime concerning the impact of various emotional disturbances on the specific trajectories of the youth involved. The study uses exclusively administrative data sets and includes a gender and racially diverse sample of 10,360 youth (30.7 % females) who were arrested at least once between ages 12 and 24 in the early 2000s. Latent class growth analysis was employed in order to identify distinct arrest trajectories of youth in the sample. Multinomial logistic regression was used to identify diagnostic and other characteristics associated with membership in the specific trajectories predicted by Moffitt’s theory. Five trajectory classes were identified, 3 of which were consistent with taxonomic theory including high and classic adolescence limited trajectory classes and a “snared adolescence limited class” described more recently by Moffitt. The distribution of youth among the 5 classes was very different for those with and without emotional disturbances. Youth with emotional disturbances in their late adolescent years were more likely to fall into the high arrest trajectory class and much less likely to fall into the low arrest trajectory class. Compared to youth without an emotional disturbance, youth with psychotic disorders were more than twice as likely to fall into the high as into the low arrest trajectory class. Youth with disruptive behavior disorders were more than twice as likely to fall into the high and intermediate classes as into the low trajectory class. Anxiety and depressive disorders were not associated with significantly greater likelihood of falling into any one of the trajectory classes. Youth in the snared adolescence limited class were more likely than those in the classic adolescence limited class to be male, black versus white and in the foster care enrollment category lending some support to Moffitt’s conceptualization of this class as an adolescence limited class composed of youth who are snared by involvement in the criminal justice and or social services systems. Implications of these results for public policy and the study of adolescence are discussed.  相似文献   
969.
Having an adult mentor during adolescence has been found to predict academic success. Building on previous work, the present study examined interactions between the type of mentor (i.e., kin, teacher, friend, or community), the time that mentor became important (i.e., before, during, or after high school), and the ethnicity of the protégé in predicting educational attainment in young adulthood. Analyses used Waves III and IV of the National Longitudinal Study of Adolescent Health (N = 2,409). Participants’ ages ranged from 18 to 27 (M = 21.75, SD = 1.79). The sample was 56.7 % female and nationally representative of ethnic diversity. Analyses showed that having a teacher-mentor was more predictive of educational attainment than having other types of mentors and that overall, having a mentor after high school predicts the most educational attainment. Kin- and community-mentors appeared to be more important to educational attainment during and before high school, respectively. Findings were consistent across ethnic groups. Overall, results highlight the value of teacher-mentors throughout childhood, adolescence, and early adulthood and our study further suggests that different types of mentors may be particularly useful at specific points in development.  相似文献   
970.
Positive relationships with parents and nonparental adults have the potential to bolster Black adolescents’ socio-emotional well-being. Though each type of intergenerational relationship has been linked to more positive youth outcomes, few studies have examined the interactive influences of parenting and natural mentoring relationships on the socio-emotional development of Black youth. In the current study, we examined associations between involved-vigilant parenting and the psychological well-being and social skills of Black early adolescents (n = 259; 58 % female; mean age = 13.56, SD = .96) across types of natural mentoring relationships. Using K-means cluster analysis, we identified two types of mentoring relationships (less connected and more connected) based on relationship length, involvement, closeness, and frequency of contact. Youth with more connected mentoring relationships (n = 123) had higher psychological well-being and social skills than youth with no mentor (n = 64) or less connected mentors (n = 72). Youth without a natural mentor and youth with less connected mentors did not differ in their levels of social skills or psychological well-being. Structural equation modeling was conducted to determine if associations between involved-vigilant parenting and youths’ psychological well-being and social skills varied among youth with a more connected mentoring relationship in comparison to youth without a mentor or with a less connected mentor, controlling for participants’ gender, age, school, and parental education. The positive associations between involved-vigilant parenting and adolescents’ psychological well-being and social skills were weaker among adolescents with a more connected mentoring relationship in comparison to their peers without or with a less connected mentoring relationship. These results suggest that youth may be more strongly influenced by involved-vigilant parenting in the absence of a strongly connected natural mentoring relationship.  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