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   3741篇
  免费   29篇
教育   2695篇
科学研究   545篇
各国文化   14篇
体育   112篇
综合类   7篇
文化理论   65篇
信息传播   332篇
  2022年   5篇
  2021年   25篇
  2020年   12篇
  2019年   33篇
  2018年   91篇
  2017年   144篇
  2016年   194篇
  2015年   133篇
  2014年   89篇
  2013年   235篇
  2012年   174篇
  2011年   189篇
  2010年   107篇
  2009年   51篇
  2008年   92篇
  2007年   80篇
  2006年   66篇
  2005年   706篇
  2004年   489篇
  2003年   326篇
  2002年   152篇
  2001年   74篇
  2000年   41篇
  1999年   35篇
  1998年   8篇
  1997年   7篇
  1996年   16篇
  1995年   9篇
  1994年   4篇
  1993年   15篇
  1992年   11篇
  1991年   9篇
  1990年   19篇
  1989年   12篇
  1988年   12篇
  1987年   10篇
  1986年   8篇
  1985年   8篇
  1983年   8篇
  1981年   8篇
  1980年   4篇
  1979年   8篇
  1978年   8篇
  1977年   6篇
  1976年   6篇
  1975年   5篇
  1973年   4篇
  1972年   3篇
  1971年   2篇
  1968年   3篇
排序方式: 共有3770条查询结果,搜索用时 15 毫秒
101.

Introduction

Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L.

Materials and methods

Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically.

Results

Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference.

Conclusion

Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.Key words: assay interference, glucose interference, preanalytical phase, creatinine, Jaffe kinetic assay, thyroid function tests  相似文献   
102.
103.
This paper aims to determine the factors affecting the decisions of both male and female secondary school pupils whether or not to pursue undergraduate studies in Computing. It is based on research conducted in Greece, on a sample of 248 pupils, 135 of whom were female. All were aged 17 and about to decide on their future undergraduate studies. Questionnaires were used, addressing issues in the following four main categories: a) the reasons pupils chose/rejected Computing, b) how family and friends, the media and the school environment contribute to their decision, c) how pupils perceived their future after studying Computing and d) how pupils perceived the profile of a computer professional in terms of gender.
Maria KordakiEmail:
  相似文献   
104.
大学和学院组织模型:历史演化的视角   总被引:4,自引:1,他引:3  
在过去五六十年里,高等教育研究者提出了多种高等教育组织模型,用它们来理解和解释美国大学和学院的组织行为。本文通过建立一个概念框架,试图解释它们的建立和发展过程。在概念框架中,“变化着的环境条件”是第一驱动力,它形成了“学校管理挑战”,影响和改变了“我们對对主要行业的概念”,从而通过它们间接地影响着大学和学院的运行机制。研究者提出的各种大学和学院组织模型就是从不同的侧面反映环境对组织的影响。  相似文献   
105.
106.
An experiment with 72 three-year-olds investigated whether encoding events while seeing iconic gestures boosts children's memory representation of these events. The events, shown in videos of actors moving in an unusual manner, were presented with either iconic gestures depicting how the actors performed these actions, interactive gestures, or no gesture. In a recognition memory task, children in the iconic gesture condition remembered actors and actions better than children in the control conditions. Iconic gestures were categorized based on how much of the actors was represented by the hands (feet, legs, or body). Only iconic hand-as-body gestures boosted actor memory. Thus, seeing iconic gestures while encoding events facilitates children's memory of those aspects of events that are schematically highlighted by gesture.  相似文献   
107.
108.
109.
    
  相似文献   
110.
The influence of sociocultural factors (ethnicity, socioeconomic status, father absence, and family size) on special education eligibility was examined for three ethnic groups. A multiple regression procedure was used to analyze the data on 300 students referred for evaluation and found to be either not eligible for services or eligible for services as mentally retarded or learning disabled. Results indicated that only socioeconomic status and ethnicity made a significant contribution to the prediction of all three groups. Individually, father absence and family size did not contribute to the prediction of special education eligibility. Results of this study suggest that legislative mandates to control for sociocultural factors in the determination of special education eligibility have been only partially successful.  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