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   1409篇
  免费   22篇
教育   1003篇
科学研究   93篇
各国文化   19篇
体育   151篇
文化理论   9篇
信息传播   156篇
  2023年   14篇
  2022年   9篇
  2021年   12篇
  2020年   32篇
  2019年   51篇
  2018年   47篇
  2017年   62篇
  2016年   52篇
  2015年   36篇
  2014年   42篇
  2013年   348篇
  2012年   37篇
  2011年   34篇
  2010年   35篇
  2009年   28篇
  2008年   34篇
  2007年   35篇
  2006年   31篇
  2005年   21篇
  2004年   24篇
  2003年   25篇
  2002年   17篇
  2001年   15篇
  2000年   20篇
  1999年   19篇
  1998年   14篇
  1997年   13篇
  1996年   15篇
  1995年   8篇
  1994年   12篇
  1993年   13篇
  1992年   18篇
  1991年   12篇
  1990年   19篇
  1989年   13篇
  1988年   9篇
  1987年   6篇
  1986年   13篇
  1985年   16篇
  1984年   11篇
  1983年   8篇
  1982年   12篇
  1980年   12篇
  1979年   12篇
  1978年   13篇
  1976年   8篇
  1975年   7篇
  1974年   7篇
  1973年   11篇
  1972年   8篇
排序方式: 共有1431条查询结果,搜索用时 15 毫秒
1.
Abstract

Carnosine was originally discovered in skeletal muscle, where it exists in larger amounts than in other tissues. The majority of research into the physiological roles of carnosine have been conducted on skeletal muscle. Given this and the potential for muscle carnosine content to be increased with supplementation, there is now a large body of research examining the ergogenic effects (or otherwise) of carnosine. More recent research, however, points towards a potential for carnosine to exert a wider range of physiological effects in other tissues, including the brain, heart, pancreas, kidney and cancer cells. Taken together, this is suggestive of a potential for carnosine to have therapeutic benefits in health and disease, although this is by no means without complication. Herein, we will provide a review of the current literature relating to the potential therapeutic effects of carnosine in health and disease.  相似文献   
2.
3.
Cain  Frank 《Minerva》2002,40(3):315-325
  相似文献   
4.
5.
The author, a professor at the University of Toronto, touches briefly on the extensive and rich archival literature that supports the teaching of macroappraisal, but notes that this is not the only educational material she offers her students when teaching appraisal theory. She discusses the usefulness to archivists of literature from the fields of ethnography, organizational knowing, records in history, personal documentary behaviour, memory, and communications, noting that the use of texts from these fields can encourage students to reflect on their own presumptions and to develop a taste for the wide reading and research that must support appraisal.  相似文献   
6.
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   
7.
8.
Abstract

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340?kcal?d?1 and 452?kcal?d?1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300?kcal?d?1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500?kcal?d?1 and obese women an increase of 0, 450 and 350?kcal?day?1. The recommendations for carbohydrate and protein intake are 175?g?d?1 and 0.88–1.1?g?kgBM?d?1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8–11.3?kg and obese women 5.0–9.1?kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5–16.0?kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.  相似文献   
9.
ABSTRACT

Increased global communication is adjusting traditional models of cross-cultural communication. Specifically, changes in international communication processes have caused increased scrutiny of cross-culture adaptation theory. This is especially true when focusing on the difference between cultural adaptation and functional fitness. The purpose of this research is to address changes in global communications by testing to see if there is a difference between two important theoretical concepts within cross-cultural adaptation theory – linear and non-linear adaptation. Findings indicate that cultural sojourners do not equate cross-cultural adaptation with linear models of functional fitness. Models that equate the two should be revisited.  相似文献   
10.
Myths are ill‐founded beliefs held uncritically by persons or groups about other persons or groups. Such myths hinder the communication process and lead to negative feelings or attitudes toward older persons with hearing loss. Hudson, Dancer, Patterson, Reynolds, and Tillery (1990) highlighted five common myths of hearing loss and aging. This article explores whether older persons themselves accept these and other myths presented by the DanPat, a 30‐item questionnaire with “Agree‐Disagree” statements such as the following: “Hearing Aids are Best Left to younger Persons Who Can Learn to Use Them,” or “Persons with Hearing Loss are Paranoid and Suspicious.”

Twenty older persons attending a Senior Companions and Foster Grandparents Health Fair filled out the DanPat with the following results to the 30 statements: informed about 14 of the statements; misinformed about 2 statements; and didn ‘t know the correct answer to 14 statements. Of the five prevalent myths presented by Hudson et al., this group of older adults still believes only one, that persons with hearing loss are excellent lipreaders. They don't know what to believe about two others, and they have discarded the remaining two. This article highlights the DanPat and provides correct answers to the questionnaire.  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