全文获取类型
收费全文 | 4566篇 |
免费 | 138篇 |
国内免费 | 181篇 |
专业分类
教育 | 3182篇 |
科学研究 | 705篇 |
各国文化 | 46篇 |
体育 | 220篇 |
综合类 | 296篇 |
文化理论 | 12篇 |
信息传播 | 424篇 |
出版年
2024年 | 3篇 |
2023年 | 27篇 |
2022年 | 46篇 |
2021年 | 114篇 |
2020年 | 125篇 |
2019年 | 102篇 |
2018年 | 92篇 |
2017年 | 83篇 |
2016年 | 109篇 |
2015年 | 133篇 |
2014年 | 159篇 |
2013年 | 278篇 |
2012年 | 355篇 |
2011年 | 245篇 |
2010年 | 171篇 |
2009年 | 247篇 |
2008年 | 331篇 |
2007年 | 376篇 |
2006年 | 414篇 |
2005年 | 305篇 |
2004年 | 298篇 |
2003年 | 198篇 |
2002年 | 155篇 |
2001年 | 119篇 |
2000年 | 95篇 |
1999年 | 72篇 |
1998年 | 45篇 |
1997年 | 42篇 |
1996年 | 42篇 |
1995年 | 20篇 |
1994年 | 16篇 |
1993年 | 22篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有4885条查询结果,搜索用时 15 毫秒
111.
采用X射线荧光光谱仪对体表为古铜色并有金属光泽的短跗星花金龟进行了体表(背、腹面)无损多元素定性检测。样品灰化后,对其灰又进行了多元素定性检测。结果发现,此种金龟子体表所呈现的金属光泽与虫体含有较多的Cu、Zn有关。 相似文献
112.
113.
Matthew Bernstein Linda Roney Meredith Kazer Elizabeth H. Boquet 《Health information and libraries journal》2020,37(3):240-244
This study explores how a three‐way collaboration between a University library, writing centre and faculty created avenues of training and support for students within a Doctor of Nursing Practice (DNP) program in an American University. The role of each partner involved in the collaboration is discussed alongside the profile of the DNP students. Lesson planning and classroom techniques for DNP information literacy classes are described and feedback from the partners and the students are discussed. The study confirms that collaboration is effective in improving research and writing skills. D.I. 相似文献
114.
2018年3月22日,美国总统特朗普正式签署美国政府对华贸易备忘录,这标志着“中美贸易战摩擦”的序幕正式拉开。本文以《人民日报》英文版(People’s Daily)为研究对象,用抽样选取的方式将该报纸上从2018年3月22日(星期四)到2019年3月28日(星期四)有关中美贸易摩擦的相关报道全部摘录下来,根据每篇报道的话语特点将其分成三个阶段,以内容分析和基于语料库的批判性话语分析为研究方法,分析得出中美贸易摩擦不同阶段的话语特点,进而得出相应的研究结论,同时提出一些富有实操价值的改进建议,为我国主流报纸更好地向世界传播中国思想、讲好中国故事献计献策。 相似文献
115.
Liu GF Zhou HK Hu H Zhu ZH Hayat Y Xu HM Yang J 《Journal of Zhejiang University. Science. B》2007,8(12):860-866
Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, including stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A),dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%~85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW. 相似文献
116.
Effect of a distal protection device on epicardial blood flow and myocardial perfusion in primary percutaneous coronary intervention 总被引:2,自引:0,他引:2
Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an adverse prognostic factor in primary PCI. In the present study the effect of a distal protection device (PercuSurge GuardWire; GW) on epicardial blood flow and myocardial perfusion was evaluated. Methods and Results: Patients with AMI were randomly divided into 2 groups, the GW and the control groups. The GW group included 52 patients with AMI who underwent primary PCI with GW protection and the control group included 60 patients who underwent primary PCI without GW protection. Epicardial blood flow in the infarct-related artery (IRA) and myocardial perfusion were evaluated according to the thrombolysis in myocardial infarction (TIMI) flow grade and the myocardial blush grade (MBG). We found TIMI score of 3 was obtained significantly more frequently in the GW group (96%) than in the control group (80%). The MBG score of 3 was obtained also significantly greater in the GW group (65%) than in the control group (33%). Conclusion: Primary PCI with GW protection can significantly improve epicardial blood flow and myocardial perfusion. 相似文献
117.
高速铁路无线通信系统半实物仿真试验平台 总被引:1,自引:0,他引:1
介绍了高速铁路无线通信系统半实物仿真试验平台的结构、工作原理。该半实物仿真平台可以对不同移动速度,在干扰条件下接收信号电平,高速铁路无线电波传播环境进行准确的模拟,配合QoS测试系统与接口监测系统,实现了在实验室环境下对高速铁路无线通信系统的性能进行评估与异常情况分析。与当前广泛采用的现场测试相比,该平台上进行半实物仿真具有实施成本低、周期短,测试环境透明、可控、可重复,不受现场环境的限制,测试完备性有保障。 相似文献
118.
Lisa Thurlow Peter Ford Grahame Hudson 《The International Journal of Art & Design Education》2019,38(2):478-491
Sketch inhibition is regularly alluded to by educators within design higher education and one with increasingly marked effects on industry. Over the past thirty years, students have been observed to engage less with the manual processes of design development process in favour of other activities perceived as more attractive, to the detriment of their development as effective designers. This article offers an evaluation of literature which supports the importance of sketching to the design process across a variety of disciplines, its anatomy and functions and demonstrates its role in cognitive support, as a language, a means of reflection, communication and storage of information and the micro‐processes it embodies. Initial findings regarding the symptoms of sketch inhibition are presented: from avoidance of studio sessions and minimal design development, to an overreliance on digital tools. It considers causes, ranging from lacking skill‐sets, psycho‐social, to technological, and although further investigation is recommended to establish depth and enable development of an appropriate pedagogical framework for its management within HE, various methods are offered at this stage for use by educators: these include fine art exercises, a rigorous pursuit of quantity and even paper type. 相似文献
119.
胡海琼 《广东技术师范学院学报》2011,(5):97-99,140
以母在上古的音韵行为非常复杂,可以跟很多声母谐声、通假,如何解释这一现象,不同学者从不同角度进行了研究,结论不一。本文从音类、音值、演变过程等几个方面对上古以母的研究情况进行综述,并指出随着研究的深入,新出现的一些问题。 相似文献
120.