全文获取类型
收费全文 | 264篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
教育 | 151篇 |
科学研究 | 90篇 |
体育 | 8篇 |
综合类 | 11篇 |
文化理论 | 1篇 |
信息传播 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 18篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 14篇 |
2012年 | 25篇 |
2011年 | 30篇 |
2010年 | 16篇 |
2009年 | 9篇 |
2008年 | 17篇 |
2007年 | 26篇 |
2006年 | 14篇 |
2005年 | 20篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有266条查询结果,搜索用时 15 毫秒
1.
零件从设计到生产过程中,加工环节对零件精度影响最大,而零件在机械加工过程中受到许多因素的影响。因此,严格控制零件的精度成为成品加工的一道重要工序。本文从人、机、料、法、环、测等几个因素分析影响机械加工工件精度的原因,以期能进一步提高零件的加工精度。 相似文献
2.
Toshiaki Miyamoto Hiroyuki Kamada Akira Tamaki Toshio Moritani 《European Journal of Sport Science》2016,16(8):1104-1110
The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?.05). Also, oxygen uptake at ventilator threshold and peak oxygen uptake during incremental exercise test significantly increased in the intervention group when compared with control group (p?.05). This study showed that prolonged low-intensity B-SES training resulted in significant increases in muscle strength and cardiorespiratory fitness in healthy subjects. Our present work suggested that B-SES training could assist patients who might have difficulty performing adequate voluntary exercise because of excessive obesity, orthopaedic problems and chronic diseases such as cardiovascular disease and type 2 diabetes. An intervention study conducted for such patients is strongly recommended. 相似文献
3.
4.
李敏涛 《温州职业技术学院学报》2007,7(3):23-26
利用工控组态软件创建电气控制线路的原理图,模拟动态演示教案,不但可以直观地表述控制原理,还可以利用工控组态中的编程功能设置故障,使学生能尽快地理解控制线路原理,掌握故障分析和排除的能力。 相似文献
5.
工程材料与成形加工基础实验是机械类专业必修的重要实践性教学环节.由于客观条件的限制,按传统方式进行实验严重影响了实验教学的效率。另外,接受远程教育的学生.无法到学校实验室做具体的实验已经成为影响远程教育教学质量的一个重要因素。而采用本项目研发的远程教育系统,不仅为解决上述问题提供了解决方案,而且对于贫困地区的教学和培训尤具优势。本文结合该系统的开发研制.论述了系统应遵循的开发流程和远程教育系统的开发技术。 相似文献
6.
7.
Professorial entrepreneurship has recently attracted much attention. This paper draws upon historical research, a survey of faculty, and an Internet-based methodology for identifying professorial affiliations with entrepreneurial firms at two of the premier electrical engineering and computer science departments in the US, The University of California, Berkeley and Stanford. We employ the concept of “nested embeddedness” to explain why the faculty members in these two institutions have different levels of entrepreneurship and corporate involvement. EE&CS faculty at both universities were found to be socially embedded in departments and disciplines that supported and placed value on entrepreneurial activities. However, while being embedded in a university environment with a history of success and high level of support for entrepreneurship, EE&CS faculty at Stanford had a significantly greater level of corporate involvement, including the founding of start-ups. Although significantly less than Stanford, the level of corporate involvement among EE&CS faculty at Berkeley was also substantial. This suggests that being embedded in an academic department and disciplines with cultures that are supportive of entrepreneurial activity can help counteract the disincentives created by a university environment that is not strongly supportive of these activities. 相似文献
8.
9.
本文简要介绍了目前高压电能计量装置所存在的缺陷,提出了如何采用技术手段和管理手段来提高高压电能计量装置的防窃电能力。 相似文献
10.
刘〓敏 《广州体育学院学报》2015,(5):81-87
目的:采用低强度电刺激治疗腓肠肌拉伤,观察其对于肌肉损伤部位成肌调节因子MyoD与Myogenin蛋白表达的影响。方法:雄性SD大鼠32只,随机分为对照组、模型组、D14组和D14-40Hz组。除对照组外其余各组建立腓肠肌拉伤动物模型。于造模后第5天D14-40Hz组开始予以电刺激,其余组继续喂养。正常对照组在实验开始当天,模型组在造模当天,D14组和D14-40Hz组在第14天进行在体力矩测试,测试结束后处死动物,分离腓肠肌采用免疫印迹法(Western blotting)测定MyoD与Myogenin蛋白表达。结果:对照组关节最大等长力矩值为0236±0045(Nm),模型组肌肉拉伤后即刻关节最大等长力矩下降为0176±0034(Nm),两者比较存在显著性差异(P<005);第14天D14-40Hz组最大等长力矩值为0247±0038(Nm),与D14组比较存在显著性差异(P<005)。MyoD与Myogenin蛋白表达测定结果:肌肉拉伤后第14天MyoD蛋白表达D14组与对照组比较无差异(P>005),但是MyoD蛋白表达D14-40Hz组比D14组增强明显(P<005);肌肉拉伤后第14天,D14-40Hz组Myogenin蛋白表达明显强于D14组(P<005)。结论:腓肠肌急性拉伤后,早期采用低强度电刺激治疗可以明显提高关节力矩,并促进了MyoD与Myogenin的表达,对组织修复起到了积极地作用。 相似文献