全文获取类型
收费全文 | 1809篇 |
免费 | 17篇 |
国内免费 | 11篇 |
专业分类
教育 | 1118篇 |
科学研究 | 135篇 |
各国文化 | 11篇 |
体育 | 416篇 |
综合类 | 1篇 |
文化理论 | 29篇 |
信息传播 | 127篇 |
出版年
2023年 | 12篇 |
2022年 | 32篇 |
2021年 | 46篇 |
2020年 | 45篇 |
2019年 | 73篇 |
2018年 | 102篇 |
2017年 | 96篇 |
2016年 | 99篇 |
2015年 | 50篇 |
2014年 | 66篇 |
2013年 | 220篇 |
2012年 | 82篇 |
2011年 | 79篇 |
2010年 | 79篇 |
2009年 | 62篇 |
2008年 | 63篇 |
2007年 | 59篇 |
2006年 | 68篇 |
2005年 | 54篇 |
2004年 | 42篇 |
2003年 | 38篇 |
2002年 | 39篇 |
2001年 | 33篇 |
2000年 | 23篇 |
1999年 | 23篇 |
1998年 | 25篇 |
1997年 | 17篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 11篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1975年 | 12篇 |
1974年 | 6篇 |
1968年 | 3篇 |
排序方式: 共有1837条查询结果,搜索用时 0 毫秒
91.
92.
Peer-feedback content is a core component of peer assessment, but the impact of various contents of feedback is hardly studied. Participants in the study were 89 graduate students who were assigned to four experimental and a control group. Experimental groups received a scenario with concise general (CGF) or elaborated specific (ESF) feedback by a high or low competent peer. ESF by a high competent peer was perceived as more adequate, but led to more negative affect. Students in CGF groups outperformed ESF groups during treatment. Groups with a low competent peer outperformed groups with a high competent peer during the posttest. Feedback perceptions and performance were uncorrelated. 相似文献
93.
94.
95.
96.
97.
Michael C. Motal Daniel A. Klaus Diana Lebherz-Eichinger Bianca Tudor Thomas Hamp Marion Wiegele Rudolf Seemann Claus G. Krenn Georg A. Roth 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2015,25(1):90-96
Introduction
Vaspin (visceral adipose tissue-derived serpin) was first described as an insulin-sensitizing adipose tissue hormone. Recently its anti-inflammatory function has been demonstrated. Since no appropriate data is available yet, we sought to investigate the plasma concentrations of vaspin in sepsis.Materials and methods
57 patients in intensive care, fulfilling the ACCP/SCCM criteria for sepsis, were prospectively included in our exploratory study. The control group consisted of 48 critically ill patients, receiving intensive care after trauma or major surgery. Patients were matched by age, sex, weight and existence of diabetes before statistical analysis. Blood samples were collected on the day of diagnosis. Vaspin plasma concentrations were measured using a commercially available enzyme-linked immunosorbent assay.Results
Vaspin concentrations were significantly higher in septic patients compared to the control group (0.3 (0.1-0.4) ng/mL vs. 0.1 (0.0-0.3) ng/mL, respectively; P < 0.001). Vaspin concentration showed weak positive correlation with concentration of C-reactive protein (CRP) (r = 0.31, P = 0.002) as well as with SAPS II (r = 0.34, P = 0.002) and maximum of SOFA (r = 0.39, P < 0.001) scoring systems, as tested for the overall study population.Conclusion
In the sepsis group, vaspin plasma concentration was about three-fold as high as in the median surgical control group. We demonstrated a weak positive correlation between vaspin and CRP concentration, as well as with two scoring systems commonly used in intensive care settings. Although there seems to be some connection between vaspin and inflammation, its role in human sepsis needs to be evaluated further.Key words: adipocytokine, inflammation, vaspin, CRP, intensive care 相似文献98.
基于显微图像的金标试纸条测试线线宽参数的测量方法具备操作方便、测量速度快、分辨率高等优点,然而图像采集系统采集到的金标试纸条的显微图像不可避免地会发生倾斜,这为后续的图像分割和参数测量带来了困难,因此需要对倾斜的金标试纸条显微图像进行校正。根据霍夫变换法和最小二乘法在直线检测中的优点和适用条件,拟采用一种结合霍夫变换法和最小二乘法的直线检测算法来求得金标试纸条图像的边缘线和边缘线的倾斜角度参数,并采用图像旋转变换算法实现对原图像的倾斜校正。实验表明,所采用的倾斜校正算法具备计算量小、占用内存小、校正精度高的优点,通过倾斜校正可以准确测量倾斜金标试纸图像的线宽参数。 相似文献
99.
The aim of the present study is to conduct a systematic review research which focuses on research studies into the school practicum. In order to identify the main issues and also to provide a contemporary picture of practicum, 114 studies published on the topic are reviewed and analysed in terms of: (i) aims, (ii) main participants, (iii) methodology used and (iv) the main outcomes emerging. Many of the reviewed studies take pre-service teachers as their main participants. The review also shows that many practicum studies are relatively small-scale studies since they are mainly qualitative focused and findings derived from a relatively small sample. This suggests that more large-scale studies are needed in the field in order to provide greater insight into teaching practicum. Finally, this systematic review provides some food for thought in the area of practicum research and promotes further studies in this complex field. 相似文献
100.