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   18229篇
  免费   497篇
管理学   2170篇
民族学   101篇
人才学   6篇
人口学   1727篇
丛书文集   106篇
教育普及   2篇
理论方法论   1675篇
现状及发展   1篇
综合类   234篇
社会学   9130篇
统计学   3574篇
  2023年   91篇
  2022年   77篇
  2021年   92篇
  2020年   281篇
  2019年   451篇
  2018年   454篇
  2017年   635篇
  2016年   448篇
  2015年   350篇
  2014年   428篇
  2013年   3101篇
  2012年   649篇
  2011年   567篇
  2010年   455篇
  2009年   428篇
  2008年   489篇
  2007年   491篇
  2006年   454篇
  2005年   414篇
  2004年   410篇
  2003年   382篇
  2002年   384篇
  2001年   464篇
  2000年   382篇
  1999年   375篇
  1998年   307篇
  1997年   278篇
  1996年   286篇
  1995年   272篇
  1994年   257篇
  1993年   248篇
  1992年   289篇
  1991年   287篇
  1990年   258篇
  1989年   257篇
  1988年   243篇
  1987年   226篇
  1986年   218篇
  1985年   246篇
  1984年   234篇
  1983年   233篇
  1982年   177篇
  1981年   155篇
  1980年   170篇
  1979年   169篇
  1978年   141篇
  1977年   140篇
  1976年   122篇
  1975年   115篇
  1974年   96篇
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
871.
This study examined whether prenatal reflective functioning (RF) was related to mothers’ interactive style across contexts with their 6‐month‐old infants (M age = 6.02 months, SD = 0.41, 54% boys), and to what extent quality of prenatal RF could account for the influence of accumulated risk on maternal interactive behavior. Accumulated risk was defined as the sum‐score of a selection of risk factors that have been associated with suboptimal infant development. Mother–infant dyads (N = 133) were observed during free play, two teaching tasks, and the Still‐Face Paradigm (SFP). Better prenatal RF was associated with more positive maternal behavior in all settings and less negative behavior during teaching and SFP reengagement. Accumulated risk and prenatal RF predicted shared variance in maternal interactive behavior (with unique predictive effects observed only for RF on sensitivity during teaching and SFP play, and for accumulated risk on sensitivity and positive engagement during SFP play, and internalizing‐helplessness during SFP reengagement). Accumulated risk had an indirect effect on maternal sensitivity during teaching and SFP play through prenatal RF. These findings suggest not only that RF may be targeted prenatally to improve mother–infant interactions, but also that enhancing RF skills may ameliorate some of the negative consequences from more stable perinatal risk factors that influence parent–child interactions.  相似文献   
872.
873.

Background

Real-world fall events objectively measured by body-worn sensors can improve the understanding of fall events in older people. However, these events are rare and hence challenging to capture. Therefore, the FARSEEING (FAll Repository for the design of Smart and sElf-adaptive Environments prolonging Independent livinG) consortium and associated partners started to build up a meta-database of real-world falls.

Results

Between January 2012 and December 2015 more than 300 real-world fall events have been recorded. This is currently the largest collection of real-world fall data recorded with inertial sensors. A signal processing and fall verification procedure has been developed and applied to the data. Since the end of 2015, 208 verified real-world fall events are available for analyses. The fall events have been recorded within several studies, with different methods, and in different populations. All sensor signals include at least accelerometer measurements and 58 % additionally include gyroscope and magnetometer measurements. The collection of data is ongoing and open to further partners contributing with fall signals. The FARSEEING consortium also aims to share the collected real-world falls data with other researchers on request.

Conclusions

The FARSEEING meta-database will help to improve the understanding of falls and enable new approaches in fall risk assessment, fall prevention, and fall detection in both aging and disease.
  相似文献   
874.
Individuals who engage in risky sexual behavior face the possibility of experiencing negative consequences. One tenet of social learning theory is that individuals engage in behaviors partly based on observations or perceptions of others’ engagement in those behaviors. The present study aimed to document these norms–behavior relationships for both risky and protective sexual behaviors, including alcohol-related sexual behavior. Gender was also examined as a possible moderator of the norms–behavior relationship. Undergraduate students (n = 759; 58.0% female) completed a Web-based survey, including various measures of drinking and sexual behavior. Results indicated that students underestimate sexual health-protective behaviors (e.g., condom use and birth control use) and overestimate the risky behaviors (e.g., frequency of drinking prior to sex, typical number of drinks prior to sex, and frequency of casual sex) of their same-sex peers. All norms were positively associated with behavior, with the exception of condom use. Furthermore, no gender differences were found when examining the relationship between normative perceptions and behavior. The present study adds to the existing literature on normative misperceptions as it indicates that college students overestimate risky sexual behavior while underestimating sexual health-protective behaviors. Implications for interventions using the social norm approach and future directions are discussed.  相似文献   
875.
We examined consistency in self-reports of age at first vaginal sex among 9,399 male and female respondents who participated in Waves III and IV (separated by approximately seven years) of the National Longitudinal Study of Adolescent Health (Add Health). Respondents were coded as consistent if they reported an age at first vaginal intercourse at Wave IV that was within one year of the age they reported at Wave III. Sociodemographic, behavioral, and cognitive predictors of consistency were examined using bivariate and multivariate logistic regression. Overall, 85.43% of respondents were able to provide consistent reports. Among both males and females, consistency was associated with age, years since first vaginal intercourse, race/ethnicity, and lifetime number of other-sex partners in final multivariate models. Respondents who were older and had more recently had their first sexual experience were more likely to be consistent. For females only, those who reported a history of nonparental, physically forced sex were less likely to be consistent. Most young adults consistently report age at first vaginal intercourse, supporting the credibility of retrospective self-reports about salient sexual events such as timing of first vaginal intercourse.  相似文献   
876.
Previous research has revealed a significant bivariate relationship between anabolic-androgenic steroid (AAS) use and reduced condom use among adolescent boys. However, to date, no known studies have explored the psychological mechanisms that may explain this relationship. Thus, the current study sought to examine two possible mediators in the association between AAS and condom use: depressive symptoms and substance use. Data were extracted from a nationally representative sample of U.S. adolescents. Participants were 3,780 U.S. high school boys who responded to self-report items assessing a number of health behaviors, including symptoms of depression, substance use, AAS use, and use of condoms during their most recent act of intercourse. Both depression and substance use were significant mediators in the relationship between AAS and condom use. However, when these effects were contrasted, the indirect effect of substance use was significantly stronger in magnitude than the effect of depression. Although AAS use was associated with sexual risk behaviors among adolescent boys, significant variance in this relationship was accounted for by elevated levels of depression and substance use, with substance use demonstrating a particularly salient pathway.  相似文献   
877.
This invited commentary responds to recent criticisms of two validated and widely used sexual function questionnaires, the Female Sexual Function Index (FSFI) and the International Index of Erectile Function (IIEF) (Forbes, Baillie, &; Schniering, 2014 Forbes , M. K. , Baillie , A. J. , &; Schniering , C. A. ( 2014 ). Critical flaws in the Female Sexual Function Index and the International Index of Erectile Function . Journal of Sex Research , 51 , 485491 . doi: 10.1080/00224499.2013.876607 [Taylor &; Francis Online], [Web of Science ®] [Google Scholar]). We take issue with the conceptual arguments presented, selective review of published literature on both instruments, and conclusions drawn from methodologically flawed findings from an Internet-based study in a nonrepresentative group of Australian men and women. Alternative perspectives on the IIEF and FSFI are presented.  相似文献   
878.
Drawing on the work of Emile Durkheim ([1912] 1995) and Rodney Stark (2001 Stark, Rodney. 2001. Gods, Rituals, and the Moral Order. Journal for the Scientific Study of Religion, 40(4): 619636. [Crossref], [Web of Science ®] [Google Scholar]) as well as research on the anti-ascetic thesis and reference group theory, we formulate a series of hypotheses regarding the effects of church attendance and importance of religion on adolescents' moral beliefs about marijuana use, getting drunk, hitting, and property offenses. The results of our study suggest that moral beliefs are more consistently and strongly related to importance of religion than to church attendance. Furthermore, much of the effect of church attendance on moral beliefs is mediated by importance of religion. Finally, we find evidence that importance of religion moderates (interaction) the effect of church attendance on moral beliefs. When adolescents believe religion is important, frequent church attendance further strengthens their moral beliefs. On the other hand, when adolescents believe religion is not important, frequent church attendance may actually reduce moral beliefs.  相似文献   
879.
The cross‐national intragenerational literature has often analyzed income mobility within short time periods over which mobility might reasonably be thought of as invariant. Here, we argue that a great social transformation—German reunification—abruptly and permanently altered mobility. Using standard measures (with panel data for the western states of Germany and the United States) over the period 1984–2006, we find the conventional result that income mobility is greater in Germany. But when we cut the data into 5‐year windows, we find that income mobility declines significantly over the years immediately following reunification in Germany but not in the United States, using both measures. (JEL J1, J6)  相似文献   
880.
This grounded theory study of 16 Mexican immigrant adolescents and 20 of their parents examines how they construct relational identities within their families, at school, with friends, and in the larger society. Results focus on a core identity bind faced by the adolescents: immigration messages from parents that say, “don't be like me” and the societal message, “you're not like us.” Response to this bind was guided by two contrasting sets of identity narratives: Empowering narratives invited an intentional approach to school and life choices. Restricting narratives maintained an ambivalent approach to school and life choices. Resolution of the identity bind was a collective, ongoing process that has implications for Mexican immigrant families and the professionals who work with them.  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