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   58964篇
  免费   2362篇
  国内免费   31篇
  61357篇
  2020年   666篇
  2019年   849篇
  2018年   1191篇
  2017年   1205篇
  2016年   1292篇
  2015年   868篇
  2014年   1077篇
  2013年   5293篇
  2012年   1908篇
  2011年   2034篇
  2010年   1226篇
  2009年   1237篇
  2008年   1869篇
  2007年   1833篇
  2006年   1638篇
  2005年   1498篇
  2004年   1479篇
  2003年   1343篇
  2002年   1421篇
  2001年   1837篇
  2000年   1735篇
  1999年   1371篇
  1998年   777篇
  1997年   675篇
  1996年   612篇
  1995年   626篇
  1994年   585篇
  1993年   601篇
  1992年   1095篇
  1991年   1034篇
  1990年   1012篇
  1989年   917篇
  1988年   858篇
  1987年   852篇
  1986年   865篇
  1985年   929篇
  1984年   759篇
  1983年   676篇
  1982年   564篇
  1981年   551篇
  1980年   522篇
  1979年   765篇
  1978年   598篇
  1976年   534篇
  1975年   675篇
  1974年   715篇
  1973年   651篇
  1972年   598篇
  1968年   582篇
  1967年   573篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Animal Cognition - The limited evidence of complex culture in non-human primates contrasts strikingly with human behaviour. This may be because non-human primates fail to use information acquired...  相似文献   
982.
The aim of this study is to gain empirical knowledge about how the Bible functions in the context of Protestant Christian primary schools in the Netherlands. It presents the results of an empirical explorative and qualitative study on the perceptions of teachers and school administrators (directors and internal supervisors) on the goals of Bible use in Protestant primary education, as well as the roles of teachers and pupils, and how these can be understood in terms of religious pedagogical models and theories. Five small focus group interviews with teachers and six interviews with school administrators revealed a variety of goals teachers hold regarding Bible use in education and a variety of divisions of teacher–learner roles in this regard. The findings also show some particular characteristics when compared with secondary schools.  相似文献   
983.
The social and environmental impacts of the global fashion industry face increasing scrutiny. As such, consumers and brands look towards ‘sustainable fashion’ for low-impact alternatives. Simultaneously, visual social media platforms such as Instagram have become prevalent places for fashion advertising and discourse. To investigate this under-researched area, the current study utilises visual content and social network analysis to explore how sustainable fashion is presented on Instagram, specifically: (a) what visual characteristics are present within sustainable fashion content, and (b) in what broader contexts and communities is discussion of sustainable fashion taking place? Posts included under the hashtag #sustainablefashion (N = 650) were inspected for visual characteristics, including type of clothing, presence of person, post setting, presence of nature, and post format. Most posts were photographs located indoors with no person and no nature-based elements. The hashtags used alongside #sustainablefashion were analysed with Gephi software to establish a social network and community groups of related topics. Network analysis revealed four key community groups: online-promotional, artisan-traditional, eco-ethical, and Malay-online-selling. Secondhand fashion also appeared to be the most prominent sustainable fashion alternative on Instagram. This study is one of the first to investigate the characteristics of user-generated #sustainablefashion content on Instagram. Whilst social media is a burgeoning avenue for research, existing studies primarily investigate how these platforms can be harnessed for advertising, rather than what users themselves are already posting. Implications for brands who use this platform and opportunities for future research are discussed.  相似文献   
984.
The COVID-19 pandemic necessitated abrupt and substantial changes in daily life, and public health strategies intended to protect physical health can negatively affect mental health and well-being, especially for individuals with pre-existing mental health challenges. For this study, we surveyed a sample of clients (N = 94) in the summer of 2020 from a community mental health clinic in the northeast United States. A mixed-methods, concurrent triangulation design was used to (a) identify client subgroups on indicators of mental health (i.e. anxious and depressive symptoms) and emotional, psychological, and social well-being using latent profile analysis (LPA), and (b) within these subgroups, examine qualitative, thematic patterns in self-described challenges, benefits and learning related to the pandemic. The LPA revealed five distinct subgroups with various levels of symptoms and well-being, including Stagnant (moderate symptoms/moderate well-being), Languishing (high symptoms/low well-being), Flourishing (low symptoms, high well-being), Fortitudinous (high symptoms, moderate well-being) and Mobilized (moderate symptoms, high well-being). These divergent subgroups support the need to conceptualise mental health symptoms apart from well-being and assess for heterogeneous constellations of such constructs among psychotherapy clients. Thematic analysis offered additional insight into pandemic experiences within each subgroup, including attention to psychological, emotional, behavioural/lifestyle, relational, physical and ecological/contextual dimensions of self-experience, as well as the ways clients had adjusted to the pandemic's circumstances. Findings support nuanced conceptualisations of positive mental health and offer insight into coping and adaptation during this public health crisis.  相似文献   
985.
986.
Ordinal data occur frequently in the social sciences. When applying principal component analysis (PCA), however, those data are often treated as numeric, implying linear relationships between the variables at hand; alternatively, non-linear PCA is applied where the obtained quantifications are sometimes hard to interpret. Non-linear PCA for categorical data, also called optimal scoring/scaling, constructs new variables by assigning numerical values to categories such that the proportion of variance in those new variables that is explained by a predefined number of principal components (PCs) is maximized. We propose a penalized version of non-linear PCA for ordinal variables that is a smoothed intermediate between standard PCA on category labels and non-linear PCA as used so far. The new approach is by no means limited to monotonic effects and offers both better interpretability of the non-linear transformation of the category labels and better performance on validation data than unpenalized non-linear PCA and/or standard linear PCA. In particular, an application of penalized optimal scaling to ordinal data as given with the International Classification of Functioning, Disability and Health (ICF) is provided.  相似文献   
987.
Curmudgeon personality, which is assessed by having participants evaluate a heterogeneous set of attitude objects, provides an applied value beyond that of more established personality traits. Recent research, for instance, suggests that curmudgeon personality is distinct from the Five Factor Model personality traits and that it predicts unique variance in important criteria, such as job attitudes and well-being. In the current paper we contribute to this literature by testing an explanation of how curmudgeon personality is distinct from other traits—their potential resistance to response distortion. We estimated response distortion for scales of curmudgeon personality and FFM traits across two quasi-experimental studies. As expected, the score shifts between nonapplicant and applicant conditions were smaller for scales of curmudgeon personality compared to scales of emotional stability and conscientiousness. We argue that curmudgeon personality scales may be more resistant to response distortion than are measures of other traits because curmudgeon personality items are semi-implicit and lack an obvious desirable response. The resistance to response distortion should serve as a call to future researchers to test the criterion validity of curmudgeon personality in regard to performance criteria.  相似文献   
988.
989.
The COVID-19 pandemic has highlighted the need for further research evaluating the validity of conducting a battery of neuropsychological assessments virtually compared with face-to-face administration. Previous research has suggested that some neuropsychological assessments yield valid results when administered virtually, however, much of the previous research focused on older adults. To determine the validity of virtually administered neuropsychological tests, 28 healthy participants were assessed using a within-subjects, counter-balanced design. Participants completed a neuropsychological assessment battery covering tests of general intellectual functioning, memory and attention, executive functioning, language and information processing speed, as well as effort. There was no significant difference between face-to-face administration of the neuropsychological battery compared with virtual administration for the majority of the tests used. However, there were significant differences in the Colour Naming Task, with participants making fewer errors on the colour naming task and inhibition/switching task when administered virtually compared with face-to-face administration. There was also a significant age cohort effect in the inhibition/switching task. There was also a trending significant difference in mode of administration for the Verbal Fluency Task. Virtually administered neuropsychological assessments largely provide a valid alternative to face-to-face assessments; however, consideration must be given to test selection as well as the population of participants that are being assessed. Other important considerations must focus on preserving the security and integrity of test materials, as well as administration in a medico-legal setting. Future research should focus on validating assessments with specific patient populations and developing a neuropsychological assessment battery using information technology.  相似文献   
990.
We investigated the role of implicit and explicit associations between harm and COVID-19 vaccines using a large sample (N = 4668) of online volunteers. The participants completed a brief implicit association test and explicit measures to evaluate the extent to which they associated COVID-19 vaccines with concepts of harmfulness or helpfulness. We examined the relationship between these harmfulness/helpfulness COVID-19 vaccine associations and vaccination status, intentions, beliefs, and behavior. We found that stronger implicit and explicit associations that COVID-19 vaccines are helpful relate to vaccination status and beliefs about the COVID-19 vaccine. That is, stronger pro-helpful COVID-19 vaccine associations, both implicitly and explicitly, related to greater intentions to be vaccinated, more positive beliefs about the vaccine, and greater vaccine uptake.  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