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   22907篇
  免费   732篇
  国内免费   1篇
管理学   3125篇
民族学   127篇
人才学   1篇
人口学   1970篇
丛书文集   101篇
教育普及   1篇
理论方法论   2232篇
综合类   222篇
社会学   11548篇
统计学   4313篇
  2023年   149篇
  2022年   84篇
  2021年   153篇
  2020年   397篇
  2019年   604篇
  2018年   696篇
  2017年   908篇
  2016年   731篇
  2015年   493篇
  2014年   653篇
  2013年   4010篇
  2012年   865篇
  2011年   799篇
  2010年   602篇
  2009年   510篇
  2008年   641篇
  2007年   612篇
  2006年   630篇
  2005年   512篇
  2004年   527篇
  2003年   445篇
  2002年   470篇
  2001年   559篇
  2000年   499篇
  1999年   466篇
  1998年   360篇
  1997年   327篇
  1996年   341篇
  1995年   330篇
  1994年   297篇
  1993年   305篇
  1992年   341篇
  1991年   327篇
  1990年   332篇
  1989年   285篇
  1988年   271篇
  1987年   233篇
  1986年   250篇
  1985年   283篇
  1984年   250篇
  1983年   219篇
  1982年   191篇
  1981年   159篇
  1980年   178篇
  1979年   199篇
  1978年   151篇
  1977年   125篇
  1976年   114篇
  1975年   107篇
  1974年   111篇
排序方式: 共有10000条查询结果,搜索用时 479 毫秒
811.
ABSTRACT

Despite both scholarly and popular claims that citizen journalism (CJ) represents a growing democratizing force in the journalistic field, recent scholarship in the area has noted the decline of the organizational population of CJ. In this paper, we investigate how individual characteristics of sites and the dynamics of larger organizational population affect a CJ site’s risk of experiencing a mortality. Drawing on the largest sample to date of US-based English-language CJ sites, this study examines the risk of site mortality through an event history framework. Findings indicate that the strongest predictor of a site’s mortality is the age of the site, consistent with organizational population theory’s ‘liability of newness.’ We also find that for-profit and community-based sites have lower rates of site mortality, indicating that adopting legitimate conventions of journalism may serve as a protective buffer to site death. The results offer mixed evidence on whether CJ has become more professionalized via attrition.  相似文献   
812.
Scholars, educators, regulators, pundits, and other observers are advocating for regulation and oversight of direct-to-consumer (DTC) genomic testing. As a result, the technology has been subject of highly visible public and regulatory controversy. In this article, we explore the nature and the shape of the sentiment of public discourse about the DTC company, 23andMe. We conduct a quantitative content analysis and qualitative framing analysis on Tweets. We find that the discourse surrounding DTC genomics and 23andMe is largely positive. We also identify a number of frames users deploy to debate, discuss, and share their experiences with DTC genomics and 23andMe. We argue that these frames create meaning around this emerging technology for its users.  相似文献   
813.
Harm-minimization strategies reduce the experience of gambling-related harms for individuals and those close to them. Most policies and particularly discussions of tool design and implementation fail to involve end users and consider their concerns and needs. This study aimed to investigate the best way to introduce a harm-minimization tool for electronic gaming machines (EGMs) that will maximize the perceived value and subsequent uptake by the intended audience of gamblers. Focus groups were conducted with 31 Australian regular EGM gamblers experiencing a range of gambling problems. Participants were asked their perspectives of a pre-commitment system (features including accessing activity statements, setting limits, viewing dynamic messages, taking breaks), including concerns, and how to enhance perceived value and usefulness. Positive attitudes about the system were expressed; however, many gamblers saw the tool as relevant only for problem gamblers. Participants indicated that value could be enhanced by making the system flexible and customizable, but still easy to use. Design and implementation strategies such as incorporating flexibility in features, ease of use, appropriate terminology, and educational efforts may address gamblers’ concerns, particularly regarding privacy and potential stigma. This would enhance user perception of harm-minimization tools as relevant and may subsequently enhance effectiveness.  相似文献   
814.
Ongoing political changes, diasporic mobilities and new communication modalities present anthropologists with novel challenges for conducting ethnographic field work. As both configurations of and expectations for varied forms of social identity change, so too has the notion of the native, what Arjun Appadurai once called the technical preserve of anthropologists. Through reflection on contemporary field work experiences in Kazakhstan, the Philippines and South Korea, this set of papers considers how changing political and cultural regimes, diasporic mobilities and social media also tag the native anthropologist, a concept which can be to the advantage of the researcher, but also can create new problems and complexities for research.  相似文献   
815.
816.
3D printing (3DP) has been heralded as a revolutionary technology that can alter the way production is organized across time and space – with important redistributive effects on geography and size of production activities. In this article, we examine the impacts that a widespread adoption of 3DP could have on restructuring, upgrading and distributing value added along manufacturing global value chains (GVC) – with brief examples from the aerospace and automotive industries. We highlight two possible scenarios for GVCs – a complementarity scenario of 3DP and traditional manufacturing overlapping, which would reproduce power relations in GVCs and the current distribution of value added in a ‘smiling curve’; and a substitution scenario of 3DP partly or fully superseding traditional manufacturing, which would have more transformational effects in terms of ‘rebundling’ activities, regionalizing or localizing GVCs, and flattening the smiling curve into a ‘smirk’.  相似文献   
817.
Infant negative affectivity predicts child anxiety. Coparenting might influence the development of anxiety by weakening this association in the case of supportive coparenting, or by strengthening this association in the case of undermining coparenting. Parents can display coparenting behaviors simultaneously (both parents being supportive or undermining), or divergently (only one parent being supportive or undermining). In our longitudinal study, we investigated whether coparenting moderated the relation between infant negative affectivity at 4 months and child anxiety symptoms 2 years later. Hundred‐sixteen couples dressed up their firstborn infants in a clothes‐changing task. We coded cooperative, mutual, neutral, and competitive coparenting behaviors. Both parents rated infant negative affectivity and child anxiety symptoms. Infant negative affectivity significantly predicted child anxiety. This association was moderated by parents' divergent cooperative coparenting: It was stronger when mothers were cooperative while fathers were neutral, and weaker when fathers were cooperative while mothers were neutral. When fathers step forward (i.e., being cooperative) and mothers step back (i.e., leaving space), they may protect their at‐risk child from developing anxiety.  相似文献   
818.
What drives infants’ attention in complex visual scenes? Early models of infant attention suggested that the degree to which different visual features were detectable determines their attentional priority. Here, we tested this by asking whether two targets—defined by different features, but each equally salient when evaluated independently—would drive attention equally when pitted head‐to‐head. In Experiment 1, we presented 6‐month‐old infants with an array of Gabor patches in which a target region varied either in color or spatial frequency from the background. Using a forced‐choice preferential‐looking method, we measured how readily infants fixated the target as its featural difference from the background was parametrically increased. Then, in Experiment 2, we used these psychometric preference functions to choose values for color and spatial frequency targets that were equally salient (preferred), and pitted them against each other within the same display. We reasoned that if salience is transitive, then the stimuli should be iso‐salient and infants should therefore show no systematic preference for either stimulus. On the contrary, we found that infants consistently preferred the color‐defined stimulus. This suggests that computing visual salience in more complex scenes needs to include factors above and beyond local salience values.  相似文献   
819.
Temperament by parenting interactions may reflect that individuals with greater risk are more likely to experience negative outcomes in adverse contexts (diathesis‐stress) or that these individuals are more susceptible to contextual influences in a “for better or for worse” pattern (differential susceptibility). Although such interactions have been identified for a variety of child outcomes, prior research has not examined approach characteristics—excitement and approach toward pleasurable activities—in the first year of life. Therefore, this study investigated whether 6‐month maternal reported infant negative affect—a phenotypic marker of risk/susceptibility—interacted with 8‐month observed parenting behaviors (positive parenting, negative parenting) to predict 12‐month infant behavioral approach. Based on a sample of mothers and their infants (= 150), results indicated that negative parenting was inversely associated with subsequent approach for infants with high, but not low, levels of negative affect. Similar results did not occur regarding positive parenting. These findings better fit a diathesis‐stress model rather than a differential susceptibility model. Implications and limitations of these findings are discussed.  相似文献   
820.
Abstract

The current study compared older children’s (11/12-year-olds) and adolescents’ (14/15-year-olds) vulnerability to false memory creation using two different methods (i.e., the Deese/Roediger-McDermott [DRM] and memory conformity paradigms) involving neutral and negative stimuli. In line with previous research, a developmental reversal effect was found for the DRM paradigm, which means that when employing this method children displayed lower false memory levels than adolescents. However, when using the memory conformity paradigm, the opposite pattern was found, with adolescents forming fewer false memories than children. This indicates that in a co-witness context, adolescents are less prone to memory errors than children. The emotional valence of the stimuli used in both paradigms did not notably affect the production of false memories. There was no statistically significant correlation between false memories as measured by the DRM and the memory conformity paradigms. Altogether, the current study indicates that there is no single type of false memory as different experimental paradigms evoke different types of erroneous recollections. Additionally, our study corroborates past findings in the literature concerning the issue of developmental reversal, strengthening the idea that under certain circumstances children might indeed be better witnesses than adolescents.  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