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   26547篇
  免费   253篇
  国内免费   21篇
教育   19319篇
科学研究   2812篇
各国文化   152篇
体育   1589篇
综合类   7篇
文化理论   489篇
信息传播   2453篇
  2021年   177篇
  2020年   254篇
  2019年   367篇
  2018年   2610篇
  2017年   2546篇
  2016年   2022篇
  2015年   444篇
  2014年   487篇
  2013年   2701篇
  2012年   576篇
  2011年   1121篇
  2010年   1190篇
  2009年   686篇
  2008年   969篇
  2007年   1436篇
  2006年   331篇
  2005年   624篇
  2004年   713篇
  2003年   590篇
  2002年   326篇
  2001年   460篇
  2000年   320篇
  1999年   259篇
  1998年   129篇
  1997年   182篇
  1996年   138篇
  1995年   131篇
  1994年   151篇
  1993年   116篇
  1992年   185篇
  1991年   203篇
  1990年   196篇
  1989年   199篇
  1988年   167篇
  1987年   162篇
  1986年   172篇
  1985年   210篇
  1984年   169篇
  1983年   153篇
  1982年   132篇
  1981年   123篇
  1980年   116篇
  1979年   165篇
  1978年   133篇
  1977年   117篇
  1976年   93篇
  1975年   112篇
  1974年   101篇
  1973年   107篇
  1971年   98篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Oh and LaRose (2016) contended that problem severity and channel publicness shape support seekers’ goals, time spent composing messages, and the sophistication of those messages. The current study seeks to replicate and extend Oh and LaRose’s study to produce a more accurate understanding of the factors that influence the sophistication of support-seeking messages online. Support seekers’ goals varied according to the severity of a stressor and the publicness of a channel, and the amount of time people spent composing a message influenced its sophistication. We extend the original study by examining associations that were not initially tested. Time spent composing messages mediated the influence of problem severity on the quality of people’s messages, and this effect was moderated by channel publicness.  相似文献   
132.
There are a number of challenges unique to the children’s book sector faced by publishers in today’s digitally-dominant business market, making it more crucial than ever for children’s book marketers to create multifaceted marketing plans that include differing but complementary approaches. Among the common marketing challenges specific to children’s books are overabundance of content, competition, access to the library market, the digital versus print dichotomy, difficulty of marketing directly to young readers on the Internet, and the dual (child and adult) target audience. While some marketing tactics must effectively attract the attention of the child reader, it is of fundamental importance (with some exceptions) for publishers, authors, and marketers of children’s books to also ensure their marketing techniques target the adult gatekeepers who are likely to purchase those books. Depending upon various factors, including age range of the reader and subject matter, marketers of children’s books are most successful when applying a mix of traditional and digital marketing techniques.  相似文献   
133.
134.
135.
The purpose of this study is to investigate the elements of Islamic children’s books that are written in English by focusing on books that are available in the Malaysian market and published in Malaysia. This study applies the content analysis method, by examining the selected books of their subject matter as well as the language. The results of the study reveal that Islamic books written for children in English are distinctive in terms of the content and language features.  相似文献   
136.
Although prior studies investigating immigration news typically documented a dominant focus on negativity and threats, only limited empirical research is available, which scrutinizes the way real-world developments affect these patterns in immigration news. This study aims to fill this void. First, we report results of a large-scale and longitudinal content analysis (N = 4,340,757) of trends in immigration news coverage in two Western European cases, Flanders (the northern, Dutch-speaking, largest region of Belgium) and the Netherlands, from 1999 to 2015. Both the salience of immigration as a news topic on itself and its linkages with three prominent issues (i.e., crime, terrorism, and socioeconomic issues) are explored. Second, this study builds on previous insights by comparing dynamics in immigration news to real-world events and developments. Overall, the results show that the linkage of immigration to issues of crime, terrorism, and the economy in Flemish and Dutch newspapers was considerable throughout the 17-year period under study. Yet there is limited evidence for a close relationship between news and real-life developments; hence, trends in immigration news seem largely unaffected by trends in society.  相似文献   
137.
Word embeddings and convolutional neural networks (CNN) have attracted extensive attention in various classification tasks for Twitter, e.g. sentiment classification. However, the effect of the configuration used to generate the word embeddings on the classification performance has not been studied in the existing literature. In this paper, using a Twitter election classification task that aims to detect election-related tweets, we investigate the impact of the background dataset used to train the embedding models, as well as the parameters of the word embedding training process, namely the context window size, the dimensionality and the number of negative samples, on the attained classification performance. By comparing the classification results of word embedding models that have been trained using different background corpora (e.g. Wikipedia articles and Twitter microposts), we show that the background data should align with the Twitter classification dataset both in data type and time period to achieve significantly better performance compared to baselines such as SVM with TF-IDF. Moreover, by evaluating the results of word embedding models trained using various context window sizes and dimensionalities, we find that large context window and dimension sizes are preferable to improve the performance. However, the number of negative samples parameter does not significantly affect the performance of the CNN classifiers. Our experimental results also show that choosing the correct word embedding model for use with CNN leads to statistically significant improvements over various baselines such as random, SVM with TF-IDF and SVM with word embeddings. Finally, for out-of-vocabulary (OOV) words that are not available in the learned word embedding models, we show that a simple OOV strategy to randomly initialise the OOV words without any prior knowledge is sufficient to attain a good classification performance among the current OOV strategies (e.g. a random initialisation using statistics of the pre-trained word embedding models).  相似文献   
138.
The need to cluster small text corpora composed of a few hundreds of short texts rises in various applications; e.g., clustering top-retrieved documents based on their snippets. This clustering task is challenging due to the vocabulary mismatch between short texts and the insufficient corpus-based statistics (e.g., term co-occurrence statistics) due to the corpus size. We address this clustering challenge using a framework that utilizes a set of external knowledge resources that provide information about term relations. Specifically, we use information induced from the resources to estimate similarity between terms and produce term clusters. We also utilize the resources to expand the vocabulary used in the given corpus and thus enhance term clustering. We then project the texts in the corpus onto the term clusters to cluster the texts. We evaluate various instantiations of the proposed framework by varying the term clustering method used, the approach of projecting the texts onto the term clusters, and the way of applying external knowledge resources. Extensive empirical evaluation demonstrates the merits of our approach with respect to applying clustering algorithms directly on the text corpus, and using state-of-the-art co-clustering and topic modeling methods.  相似文献   
139.
Although much has been written about formal archival spaces, little scholarship has addressed the physical spaces of community archives. This paper asks: How do community members imagine the physical spaces that steward identity-based community archives? Based on focus groups with more than 54 community archives users at five different community archives sites across Southern California, this paper examines how members of marginalized communities conceive of the physical space inhabited by community archives representing their communities. The sites explored range from a prominent location on a university campus, to storefronts, strip malls, and small cinderblock buildings. Yet across sites, users spoke about community archives spaces as symbolic and affectively moving locations. Many users described their community archives site as a “home-away-from-home,” marked by intergenerational dialog and a profound sense of belonging. For other users, community archives sites were described as “politically generative spaces” which foster dialog and debate about identity, representation, and activism and enable the community to envision its future. And yet, while the very existence of community archives is political, many participants felt that the full political potential of these sites is not yet realized. By listening to the voices of the communities represented and served by community archives, our research both indicates that a shift is warranted in archival metaphors of space and reveals how community archives are personally and politically transformative spaces for the communities they represent and serve.  相似文献   
140.
The growth of archival studies programs has prompted archival scholars to establish an international network for supporting collaborative research, curriculum development, and pedagogy. Doctoral education is key to the sustainability of such programs and the continuation of the network over time. We carried out longitudinal research to survey the population of doctoral students attending one or more Archival Education and Research Institutes (AERI), an annual meeting first held in 2009. Building on prior research on graduate archival education, we gathered demographic and qualitative data about doctoral students specializing in archival studies who are based in several countries including the USA. We sought to assess attendee motivations, guide conference planning, and help advance overall AERI objectives. Our study provides a baseline understanding of the disciplinary backgrounds, research directions, and specific professional development activities that doctoral students in archival studies pursued around the globe from 2013 to 2015. This paper argues that doctoral education should continue to be a particular subject of archival research and indicates how archival students’ range of academic interests is diversifying and strengthening the scholarly community.  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