全文获取类型
收费全文 | 34227篇 |
免费 | 399篇 |
国内免费 | 15篇 |
专业分类
教育 | 25015篇 |
科学研究 | 3190篇 |
各国文化 | 218篇 |
体育 | 2227篇 |
综合类 | 13篇 |
文化理论 | 559篇 |
信息传播 | 3419篇 |
出版年
2022年 | 170篇 |
2021年 | 261篇 |
2020年 | 382篇 |
2019年 | 607篇 |
2018年 | 2906篇 |
2017年 | 2810篇 |
2016年 | 2242篇 |
2015年 | 550篇 |
2014年 | 769篇 |
2013年 | 4498篇 |
2012年 | 864篇 |
2011年 | 1367篇 |
2010年 | 1313篇 |
2009年 | 901篇 |
2008年 | 1169篇 |
2007年 | 1624篇 |
2006年 | 487篇 |
2005年 | 789篇 |
2004年 | 816篇 |
2003年 | 717篇 |
2002年 | 474篇 |
2001年 | 479篇 |
2000年 | 415篇 |
1999年 | 361篇 |
1998年 | 203篇 |
1997年 | 223篇 |
1996年 | 240篇 |
1995年 | 235篇 |
1994年 | 182篇 |
1993年 | 201篇 |
1992年 | 321篇 |
1991年 | 304篇 |
1990年 | 298篇 |
1989年 | 298篇 |
1988年 | 255篇 |
1987年 | 301篇 |
1986年 | 265篇 |
1985年 | 304篇 |
1984年 | 246篇 |
1983年 | 211篇 |
1982年 | 190篇 |
1981年 | 163篇 |
1980年 | 153篇 |
1979年 | 258篇 |
1978年 | 182篇 |
1977年 | 168篇 |
1976年 | 154篇 |
1975年 | 141篇 |
1974年 | 147篇 |
1971年 | 140篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Jerry W. Gilley Anne M. Gilley Sherry Avery Jackson Heshium Lawrence 《Performance Improvement Quarterly》2015,28(3):71-93
This paper focuses on seven major managerial practices and three negative conditions that must be managed to enhance employee growth and development. These managerial practices and conditions have significant potential for human resource development practitioners and performance improvement technologists by providing new perspectives to improve employee performance through employee growth and development activities. Surveys measuring employee perceptions of manager behaviors were administered to 503 MBA and PhD students from the United States, resulting in 463 useable responses. The hypotheses were tested using linear regression and structural equation modeling. Based on the analysis, the researchers found that involving employees in decision making, motivating employees, treating employees as unique individuals, and making certain that managers are effective have the highest influence on employee growth and development. 相似文献
952.
Dong-Dong Wu Cui-Ping Yang Ming-Shan Wang Kun-Zhe Dong Da-Wei Yan Zi-Qian Hao Song-Qing Fan Shu-Zhou Chu Qiu-Shuo Shen Li-Ping Jiang Yan Li Lin Zeng He-Qun Liu Hai-Bing Xie Yun-Fei Ma Xiao-Yan Kong Shu-Li Yang Xin-Xing Dong Ali Esmailizadeh David M Irwin Xiao Xiao Ming Li Yang Dong Wen Wang Peng Shi Hai-Peng Li Yue-Hui Ma Xiao Gou Yong-Bin Chen Ya-Ping Zhang 《国家科学评论(英文版)》2020,7(6):952
Abundant and diverse domestic mammals living on the Tibetan Plateau provide useful materials for investigating adaptive evolution and genetic convergence. Here, we used 327 genomes from horses, sheep, goats, cattle, pigs and dogs living at both high and low altitudes, including 73 genomes generated for this study, to disentangle the genetic mechanisms underlying local adaptation of domestic mammals. Although molecular convergence is comparatively rare at the DNA sequence level, we found convergent signature of positive selection at the gene level, particularly the EPAS1 gene in these Tibetan domestic mammals. We also reported a potential function in response to hypoxia for the gene C10orf67, which underwent positive selection in three of the domestic mammals. Our data provide an insight into adaptive evolution of high-altitude domestic mammals, and should facilitate the search for additional novel genes involved in the hypoxia response pathway. 相似文献
953.
Cong Liu Feng An Paria S M Gharavi Qinwen Lu Junkun Zha Chao Chen Liming Wang Xiaozhi Zhan Zedong Xu Yuan Zhang Ke Qu Junxiang Yao Yun Ou Zhiming Zhao Xiangli Zhong Dongwen Zhang Nagarajan Valanoor Lang Chen Tao Zhu Deyang Chen Xiaofang Zhai Peng Gao Tingting Jia Shuhong Xie Gaokuo Zhong Jiangyu Li 《国家科学评论(英文版)》2020,7(1):84
Complex oxides with tunable structures have many fascinating properties, though high-quality complex oxide epitaxy with precisely controlled composition is still out of reach. Here we have successfully developed solution-based single-crystalline epitaxy for multiferroic (1-x)BiTi(1-y)/2FeyMg(1-y)/2O3–(x)CaTiO3 (BTFM–CTO) solid solution in large area, confirming its ferroelectricity at the atomic scale with strong spontaneous polarization. Careful compositional tuning leads to a bulk magnetization of 0.07 ± 0.035 μB/Fe at room temperature, enabling magnetically induced polarization switching exhibiting a large magnetoelectric coefficient of 2.7–3.0 × 10−7 s/m. This work demonstrates the great potential of solution processing in large-scale complex oxide epitaxy and establishes novel room-temperature magnetoelectric coupling in epitaxial BTFM–CTO film, making it possible to explore a much wider space of composition, phase, and structure that can be easily scaled up for industrial applications. 相似文献
954.
Living birds are unique among vertebrates in the formation of a female-specific bone tissue called medullary bone (MB) that is strictly associated with reproductive activity. MB is a rapidly mobilized source of calcium and phosphorus for the production of eggshell. Among living taxa, its skeletal distribution can be highly extensive such that it even exists in the ribs of some species. Due to its ephemeral nature, MB is rarely fossilized and so little is understood with regard to the origin of MB and its skeletal distribution in early taxa. Here we describe a new Early Cretaceous enantiornithine bird, Mirusavis parvus, gen. et. sp. nov., indicating that skeleton-wide distribution of MB appeared early in avian evolution. We suggest that this represents the plesiomorphic condition for the Aves and that the distribution of MB observed among extant neornithines is a product of increased pneumatization in this lineage and natural selection for more efficient distribution of MB. 相似文献
955.
A survey was conducted of 231 psychologists from a midwestern state. Investigators surveyed perceptions of job satisfaction, job stability, and quality of professional life. Responses of rural and urban professionals were compared. While resembling urban colleagues in most regards, rural psychologists appear more satisfied with working environments and job policies. Discussion is presented on differences between the two groups on a number of variables influencing perceptions. 相似文献
956.
The Slosson Intelligence Test (revised norms) (SIT) and the WISC-R were compared in two samples of children. In the first sample, there were 34 black and 27 white rural Southeastern Alabama children being considered for special education classes. In the second sample, there were 4 black and 81 white suburban Alabama children being considered for classes for the talented and gifted. In both samples, correlations between the SIT IQ and WISC-R Full Scale IQ were significant (rs of .70 and .48, respectively). However, in the special education sample, SIT IQs were significantly higher than WISC-R Full Scale IQs by about 7 points. The results from both samples provide a moderate degree of support for the concurrent validity of the revised SIT norms, using the WISC-R as the criterion. However, the IQs on the two tests may not be interchangeable. 相似文献
957.
A sample of 63 gifted elementary-school students was administered the Bender Visual-Motor Gestalt Test and the Developmental Test of Visual-Motor Integration for comparative purposes and to test Koppitz hypothesis that gifted students have advanced visual-motor development. Group results revealed no significant differences between the two tests, that they did correlate significantly, and that younger students in particular had advanced visual-motor development when tested using these two tools. 相似文献
958.
959.
A group of 95 black and 52 white low socioeconimic children assigned to special education calsses were initially given the Stanford-Binet (1972 norms) and three years later the WISC-R. Correlations between the Stanford-Binet and WISC-R Full Scale IQs were significant in both ethnic groups, with r=.60 for the total group. Correlations between the Stanford-Binet and WISC-R subtests also were generally signiificant (rs between .29 and .52 for the total group). Stanford-Binet and WISC-R Full Scale IQs did not differ significantly. For this sample of special education children, the Stanford-Binet was found to have satisfactory predictive validity. 相似文献
960.
Howard M. Knoff 《Psychology in the schools》1985,22(4):410-418
Four hundred regular and special educators from New York (a categorical labeling state) and Massachusetts (a noncategorical labeling state) were surveyed on their mainstreaming attitudes and perceptions of handicapped exceptional children. Among the topics investigated were educators' attitudes toward the effects on these children of different educational placements, their reactions to integrating these children into regular classrooms, their knowledge of their special education responsibilities, and their inclusions in their building-level special education processes. Results, implications, and future research directions are discussed, so that services to handicapped exceptional children can be improved and implemented. 相似文献