全文获取类型
收费全文 | 3598篇 |
免费 | 10篇 |
专业分类
教育 | 2500篇 |
科学研究 | 573篇 |
各国文化 | 6篇 |
体育 | 136篇 |
综合类 | 7篇 |
文化理论 | 65篇 |
信息传播 | 321篇 |
出版年
2022年 | 6篇 |
2021年 | 23篇 |
2020年 | 13篇 |
2019年 | 24篇 |
2018年 | 80篇 |
2017年 | 121篇 |
2016年 | 205篇 |
2015年 | 128篇 |
2014年 | 80篇 |
2013年 | 213篇 |
2012年 | 163篇 |
2011年 | 185篇 |
2010年 | 96篇 |
2009年 | 56篇 |
2008年 | 103篇 |
2007年 | 82篇 |
2006年 | 75篇 |
2005年 | 709篇 |
2004年 | 483篇 |
2003年 | 312篇 |
2002年 | 148篇 |
2001年 | 80篇 |
2000年 | 42篇 |
1999年 | 38篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有3608条查询结果,搜索用时 9 毫秒
141.
142.
143.
石敏俊 《浙江大学学报(A卷英文版)》2004,5(12):1533-1542
Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion. 相似文献
144.
It is the argument of this paper that the literature on mid-century racial discrimination in sport is incomplete in that it ignores the experiences of a small, but relatively significant, group of African-American football players who actually chose to leave their own country – and correspondingly leave the racially-charged environment of mid-twentieth-century USA – to head north to play professional football in the Canadian Football League (CFL). Beginning in 1946, a steady flow of African-Americans began to migrate to the CFL which, at the time, was a legitimate competitor league to the NFL. This paper attempts to test a perception seemingly held by some that, by moving to Canada, African-American football players were able to escape the racial injustices they often suffered in the US. This view appears to have its roots in the notion that Canada is a ‘gentler’, more tolerant society, without the divisive socio-political history that characterizes much of the race relations in the US. This paper tests these notions using a variety of empirical approaches. The results indicate that, while African-Americans were better represented in the CFL relative to the NFL, African-Americans still faced some level of entry discrimination in the CFL. In particular, African-American players in the CFL outperformed their white counterparts on numerous performance dimensions, indicating the overall talent level in the CFL could have been further improved by employing an even greater number of African-Americans. Additionally, the paper finds that those CFL teams that employed the highest percentage of African-Americans were those teams that had the most on-field success. Finally, the paper analyses prices of player trading cards from that era, and finds that cards of African-Americans were undervalued, relative to white CFL players of equal talent. 相似文献
145.
146.
Wolfgang Wahlster J?rg Baus Christian Kray und Antonio Krüger 《Informatik - Forschung und Entwicklung》2001,16(4):233-241
Zusammenfassung. Die intelligente Ressourcenadaption ist eine der gro?en Herausforderungen für die n?chste Generation mobiler Navigationssysteme.
Da man typischerweise mehrere Fortbewegungsarten oder Verkehrsmittel kombinieren muss, um an einen Zielort zu gelangen, muss
sichergestellt werden, dass mobile, allgegenw?rtige Navigationshilfen dies über eine jeweils situationsangepasste Benutzerschnittstelle
unterstützen. Der notwendige Wechsel zwischen verschiedenen Positionierungstechnologien soll für den Endbenutzer m?glichst
unbemerkt bleiben. Im folgenden wird ein hybrides Personennavigationssystem vorgestellt, das die in bestimmten Fortbewegungssituationen
verfügbaren Positionierungstechnologien und deren Genauigkeit optimal nutzt, um die Pr?sentation der Wegbeschreibung auf verschiedene
Endger?te und Ausgabemodalit?ten sowie die kognitive Ressourcenlage des Benutzers zu adaptieren.
Eingegangen am 28. Februar 2001 / Angenommen am 8. August 2001 相似文献
147.
G?khan ?zsoy 《Asia Pacific Education Review》2011,12(2):227-235
The aim of this study is to determine fifth-grade students’ metacognitive knowledge and skills and its relationship with mathematics
achievements. A total of 242 primary school students from six different schools were participated in the study. Turkish version
of Metacognitive Knowledge and Skills Assessment (MSA-TR) was used to measure metacognitive knowledge and skills. The results
demonstrated a significant and positive relationship (r = .648, p < .01) between metacognition and mathematics achievement. Furthermore, research results showed that 42% of total variance
of mathematics achievement could be explained with metacognitive knowledge and skills. 相似文献
148.
Mengwen?Liu Yi?FangEmail author Alexander?G.?Choulos Dae?Hoon?Park Xiaohua?Hu 《Information Retrieval》2017,20(6):575-605
Product reviews have become an important resource for customers before they make purchase decisions. However, the abundance of reviews makes it difficult for customers to digest them and make informed choices. In our study, we aim to help customers who want to quickly capture the main idea of a lengthy product review before they read the details. In contrast with existing work on review analysis and document summarization, we aim to retrieve a set of real-world user questions to summarize a review. In this way, users would know what questions a given review can address and they may further read the review only if they have similar questions about the product. Specifically, we design a two-stage approach which consists of question selection and question diversification. For question selection phase, we first employ probabilistic retrieval models to locate candidate questions that are relevant to a given review. A Recurrent Neural Network Encoder–Decoder is utilized to measure the “answerability” of questions to a review. We then design a set function to re-rank the questions with the goal of rewarding diversity in the final question set. The set function satisfies submodularity and monotonicity, which results in an efficient greedy algorithm of submodular optimization. Evaluation on product reviews from two categories shows that the proposed approach is effective for discovering meaningful questions that are representative of individual reviews. 相似文献
149.
This article presents an analysis of the concept of disability in Amartya Sen’s capabilities and functionings approach in the context of Information and Communication Technologies (ICT). Following a critical review of the concept of
disability—from its traditional interpretation as an essentially medical concept to its later interpretation as a socially
constructed category—we will introduce the concept of functional diversity. The importance of human diversity in the capabilities and functionings approach calls for incorporating this concept into
the analysis of well-being and quality of life in persons with disability—aspects in which ICT currently plays a major role.
When one contemplates these technologies, it becomes clear that factors such as accessibility, design for all, and user participation
in development and implementation processes are key strategies in promoting equal rights and equal opportunity for persons
with disability in the different environments of the information society. 相似文献
150.
试论“网球肘”的成因、诊断、预防与治疗 总被引:2,自引:0,他引:2
“网球肘”是网球运动中常见的一种伤病。通过研究“网球肘”的成因、诊断、预防与治疗,预防伤病的发生。 相似文献