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   3022篇
  免费   41篇
  国内免费   9篇
教育   2114篇
科学研究   284篇
各国文化   52篇
体育   218篇
综合类   2篇
文化理论   24篇
信息传播   378篇
  2023年   12篇
  2022年   29篇
  2021年   52篇
  2020年   105篇
  2019年   129篇
  2018年   152篇
  2017年   158篇
  2016年   141篇
  2015年   100篇
  2014年   134篇
  2013年   759篇
  2012年   105篇
  2011年   95篇
  2010年   98篇
  2009年   86篇
  2008年   89篇
  2007年   74篇
  2006年   72篇
  2005年   38篇
  2004年   35篇
  2003年   49篇
  2002年   36篇
  2001年   37篇
  2000年   31篇
  1999年   22篇
  1998年   18篇
  1997年   22篇
  1996年   19篇
  1995年   17篇
  1994年   16篇
  1993年   23篇
  1992年   16篇
  1991年   25篇
  1990年   10篇
  1989年   17篇
  1988年   12篇
  1987年   20篇
  1986年   15篇
  1985年   23篇
  1984年   16篇
  1983年   11篇
  1982年   16篇
  1981年   14篇
  1980年   14篇
  1979年   14篇
  1978年   15篇
  1977年   7篇
  1975年   7篇
  1974年   8篇
  1973年   9篇
排序方式: 共有3072条查询结果,搜索用时 15 毫秒
101.
Self-rating bias is particularly likely in organizational behavior research as individuals tend to inflate their expertise, skills and character. This study aims to examine how two culturally diverse groups of teachers and their reporting officers respond to self-ratings of their own teaching skills and leadership skills respectively. It is posited that such response may be culturally based. To ensure validity of comparisons, analyses were done using linear Rasch measures in logits rather than the non-linear raw scores. No significant differences were found between the perceptions of Singaporean teachers and their reporting officers on teaching and leadership skills. The Bahraini data however revealed teachers’ perceptions of own teaching skills were significantly higher than that of their reporting officers. The opposite is true for the Reporting officers’ perceptions of our leadership skills. Bahraini teachers’ perceptions of their own teaching skills were also found to be significantly higher than that of their Singaporean counterparts. The findings support the notion that individuals’ thinking and behavior is influenced by how they process social and cultural information.  相似文献   
102.
Instead of the commonly accepted inverse square law, Lotka's original formulation was based on a more general inverse power law: xn·y = c. The exponent and the constant must be estimated from the given set of author productivity data. A step-by-step outline is presented for testing the applicability of Lotka's law. Steps include the computation of the values of the exponent and the constant based on Lotka's method, and the test for significance of the observed frequency distribution against the estimated theoretical distribution derived from Lotka's formula.  相似文献   
103.
104.
105.
This study investigates the relationship between cultural orientation (individualistic or collectivistic culture) and consumers' attribution styles (dispositional and situational attributions) as well as the consequences of attribution styles on brand evaluation and purchase intention. The study also examines how people perceive different types of negative celebrity information (self-oriented and other-oriented negative information) and how their identification with a celebrity endorser affects their response to negative information. The findings suggest that culture influences how consumers – having been exposed to negative celebrity information – make attributions. Dispositional attributions lead to more negative brand evaluation as well as to negative purchase intention. Other-oriented negative information leads to, among Korean consumers, more negative brand evaluation. Finally, the study found that consumers highly identified with a celebrity endorser are less likely to be influenced by negative celebrity information.  相似文献   
106.
Bioecological systems theory provides a framework to understand how factors in the child's environment contribute to parent-child differences in estimations of how often children are helped by their Internet use. A national sample survey of 456 matched parent-child pairs investigated how parents-child relational factors, parental attitudes toward the Internet, and the bio-ecology of the child, are related to differing perceptions of the frequency of using the Internet to seek help with homework assignments, to aid in identity development, and to find health information. While previous research shows that parents underestimate risky online behaviors, we investigate whether parent-child differences will emerge in regards to how often the child engages in the behaviors under investigation here. The findings show that parents overestimate these online activities, suggesting they are biased in their estimations. Parent-child relational factors emerged as predictors of parental overestimation for each of these online activities, with trust perceptions as the most consistent predictor. Parental attitudes toward the Internet predicted parent-child differences in perceptions of how frequently the child used the Internet for help with homework and identity development, while the bioecology of the child was only predictive in the case of using the Internet for help with homework.  相似文献   
107.
Mass transport in porous materials is universal in nature, and its worth attracts great attention in many engineering applications. Plant leaves, which work as natural hydraulic pumps for water uptake, have evolved to have the morphological structure for fast water transport to compensate large water loss by leaf transpiration. In this study, we tried to deduce the advantageous structural features of plant leaves for practical applications. Inspired by the tissue organization of the hydraulic pathways in plant leaves, analogous double-layered porous models were fabricated using agarose hydrogel. Solute transport through the hydrogel models with different thickness ratios of the two layers was experimentally observed. In addition, numerical simulation and theoretical analysis were carried out with varying porosity and thickness ratio to investigate the effect of structural factors on mass transport ability. A simple parametric study was also conducted to examine unveiled relations between structural factors. As a result, the porosity and thickness ratio of the two layers are found to govern the mass transport ability in double-layered porous materials. The hydrogel models with widely dispersed pores at a fixed porosity, i.e., close to a homogeneously porous structure, are mostly turned out to exhibit fast mass transport. The present results would provide a new framework for fundamental design of various porous structures for effective mass transport.  相似文献   
108.
We employed a microfluidic device to study the effects of hydraulic pressure on cardiomyoblast H9c2. The 170 mm Hg pressure increased the cellular area and the expression of atrial natriuretic peptide. With the same device, we demonstrated that the effects of hydraulic pressure on the cardiomyoblast could be reduced by the inhibitor of focal adhesion kinase. This mechanical–chemical antagonism could lead to a potential therapeutic strategy of hypertension-induced cardiac hypertrophy.  相似文献   
109.
Affinity reagents recognizing biomarkers specifically are essential components of clinical diagnostics and target therapeutics. However, conventional methods for screening of these reagents often have drawbacks such as large reagent consumption, the labor-intensive or time-consuming procedures, and the involvement of bulky or expensive equipment. Alternatively, microfluidic platforms could potentially automate the screening process within a shorter period of time and reduce reagent and sample consumption dramatically. It has been demonstrated recently that a subpopulation of tumor cells known as cancer stem cells possess high drug resistance and proliferation potential and are regarded as the main cause of metastasis. Therefore, a peptide that recognizes cancer stem cells and differentiates them from other cancer cells will be extremely useful in early diagnosis and target therapy. This study utilized M13 phage display technology to identify peptides that bind, respectively, to colon cancer cells and colon cancer stem cells using an integrated microfluidic system. In addition to positive selection, a negative selection process was integrated on the chip to achieve the selection of peptides of high affinity and specificity. We successfully screened three peptides specific to colon cancer cells and colon cancer stem cells, namely, HOLC-1, HOLC-2, and COLC-1, respectively, and their specificity was measured by the capture rate between target, control, and other cell lines. The capture rates are 43.40 ± 7.23%, 45.16 ± 7.12%, and 49.79 ± 5.34% for colon cancer cells and colon cancer stem cells, respectively, showing a higher specificity on target cells than on control and other cell lines. The developed technique may be promising for early diagnosis of cancer cells and target therapeutics.  相似文献   
110.
One of the bedrock of Sustainable Development Goals (SDGs) is eradication of poverty and hunger. In an attempt to actualize this goal, the role of public libraries in information provision to agricultural extension agents in Nigeria becomes paramount. This paper discusses provision of information to agricultural extension agents in a developing country. It starts with the concept of extension agents and the essence of information provision to them. It further discusses types, sources and challenges of public libraries in information provision to agricultural extension workers in a developing country. Some of the challenges are as follows: poor funding of public libraries, demotivated staff, and so on. Based on these discussions, the paper recommended adequate training and retraining of staff, adequate funding of public libraries by the federal, state and local government, the revitalization of the abandoned mobile library services among others. The paper therefore concludes that information provision to agricultural extension agents by public library is very crucial for national development. The current state of poverty, hunger and lack in Nigeria and some other African countries could be reduced to a great extent if current, relevant and up-to-date information are provided by libraries to the concerned agencies.  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