全文获取类型
收费全文 | 2032篇 |
免费 | 224篇 |
国内免费 | 221篇 |
学科分类
工业技术 | 2477篇 |
出版年
2024年 | 7篇 |
2023年 | 34篇 |
2022年 | 50篇 |
2021年 | 69篇 |
2020年 | 101篇 |
2019年 | 72篇 |
2018年 | 79篇 |
2017年 | 83篇 |
2016年 | 74篇 |
2015年 | 117篇 |
2014年 | 180篇 |
2013年 | 161篇 |
2012年 | 187篇 |
2011年 | 172篇 |
2010年 | 138篇 |
2009年 | 137篇 |
2008年 | 120篇 |
2007年 | 136篇 |
2006年 | 95篇 |
2005年 | 77篇 |
2004年 | 64篇 |
2003年 | 60篇 |
2002年 | 45篇 |
2001年 | 44篇 |
2000年 | 27篇 |
1999年 | 30篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 4篇 |
1995年 | 10篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1987年 | 4篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 5篇 |
1964年 | 4篇 |
1963年 | 3篇 |
1962年 | 1篇 |
1961年 | 2篇 |
1960年 | 7篇 |
1958年 | 3篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1955年 | 3篇 |
1954年 | 3篇 |
排序方式: 共有2477条查询结果,搜索用时 31 毫秒
1.
Kalai Selvan Ramalingam Karmegam Karuppiah Shiamala Devi Ramaiya Vivien How Enoch Kumar Perimal Hassan Sadeghi Naeini Sivasankar Sambasivam Kulanthayan KC Mani 《人机工程学与制造业中的人性因素》2019,29(5):426-434
Many occupations require workers to stand for long periods of time without proper interventions, which causes discomfort in the back and lower limbs. Therefore, this study aims to assess the effectiveness in alleviating body muscle discomfort during prolonged standing through the use of a calf massager. This study was conducted among male workers at a manufacturer with production line workers and the list was obtained from the HR Department and simple random sampling was done by number categorization. A total of 100 respondents (50 respondents for both the control and the experimental groups) participated in this study. The experiment took place in a room with a similar setup for the production line. Each respondent was requested to perform the simulated task for 2 hr. For the experimental group, the calf massager was turned on every 15 min. At every 15‐min interval after turning on the calf massager, respondents from both groups were required to evaluate their discomfort level on a Borg's scale CR‐10 questionnaire. The results showed that the level of body discomfort among respondents in the experimental group reduced (20–30%) compared with that of the control group. Multivariate analysis results revealed that the discomfort rating for the lower back, knees, thighs, calves, and feet was significantly lower (p < .05) among the experimental group compared with the control group. For lower body parts, the lower back region was statistically significant (p < .05) at the 90th, 105th, and 120th min; the thigh region was statistically significant (p < .05) at the 120th min; the knee region was statistically significant (p < .05) at the 105th and 120th min; the calf region was statistically significant (p < .05) at all minute intervals except the 15th and 45th min, while the feet region, was statistically significant at the 105th and 120th min. Therefore, this study indicates that calf massage treatment is capable of reducing body muscle discomfort during prolonged standing and highlights the significance of calf massage. 相似文献
2.
The network reconfiguration is an important stage of restoring a power system after a complete blackout or a local outage. Reasonable planning of the network reconfiguration procedure is essential for rapidly restoring the power system concerned. An approach for evaluating the importance of a line is first proposed based on the line contraction concept. Then, the interpretative structural modeling (ISM) is employed to analyze the relationship among the factors having impacts on the network reconfiguration. The security and speediness of restoring generating units are considered with priority, and a method is next proposed to select the generating unit to be restored by maximizing the restoration benefit with both the generation capacity of the restored generating unit and the importance of the line in the restoration path considered. Both the start-up sequence of generating units and the related restoration paths are optimized together in the proposed method, and in this way the shortcomings of separately solving these two issues in the existing methods are avoided. Finally, the New England 10-unit 39-bus power system and the Guangdong power system in South China are employed to demonstrate the basic features of the proposed method. 相似文献
3.
van Dick Rolf; Wagner Ulrich; Pettigrew Thomas F.; Christ Oliver; Wolf Carina; Petzel Thomas; Castro Vanessa Smith; Jackson James S. 《Canadian Metallurgical Quarterly》2004,87(2):211
Furthering G. W. Allport's (1954) contentions for optimal contact, the authors introduce a new construct: the perceived importance of contact. They propose that perceived importance is the best proximal predictor of contact's reduction of prejudice. If individuals have opportunities for contact at work or in the neighborhood, their chances to have intergroup acquaintances and friends increase. Intergroup contact among acquaintances and friends can be perceived as more or less important, which in turn determines intergroup evaluations. A 1st study shows that the new measure of perceived importance is indeed distinct from established quantity and quality indicators. The results are cross-validated in a 2nd study that also sheds light on the meaning of importance. In 3rd and 4th studies, structural equation analyses and a meta-analysis support the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
5.
螺旋埋弧焊管管端X射线拍片探伤重要性的分析 总被引:1,自引:1,他引:0
简要分析了螺旋埋弧焊管中自动超声波探伤、手动超声波探伤、工业电视X射线探伤、X射线拍片探伤四种方法在管端探伤的特点.强调了X射线拍片探伤在螺旋管焊缝探伤中的重要地位,指出X射线拍片探伤对确保输送油、燃气等危险介质的螺旋埋弧焊管的焊缝质量有重要作用. 相似文献
6.
通过一起由二次回路接线错误引发的事故分析,阐述二次回路的重要性。从设计、安装、调试和管理上对二次回路进行探讨,提出反事故措施和对策,以防止类似事故的发生。 相似文献
7.
自动传输收视率调查系统 总被引:1,自引:1,他引:0
综述了当前收视率调查的主要方法 ,提出一种自动传输的收视率调查系统 ,详细介绍了该系统的组成、原理和设计思想 ,并分析了不同实现方法的优点与不足。应用表明 ,该系统在同类产品中具有明显优势 相似文献
8.
9.
Burns G. Leonard; Gomez Rapson; Walsh James A.; de Moura Marcela Alves 《Canadian Metallurgical Quarterly》2003,15(1):118
G. J. DuPaul (see record 2003-02033-012) offered two suggestions for additional research to understand the strong source effects reported by R. Gomez, G. L Burns, J. A. Walsh, and M. A. de Moura (see record 2003-02033-001) in attention-deficit/ hyperactivity disorder (ADHD) rating scales. The first suggestion was to determine whether the source effects represent mostly bias or accuracy. The second suggestion was to minimize source effects through the development of better ADHD rating scales. Because source effects can represent bias or accuracy, it is important to minimize the bias aspect through content validation procedures prior to attempts to determine whether source effects better reflect bias or accuracy. This comment offers various suggestions to reduce the bias in ADHD rating scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
结构安全性综合评估方法的研究 总被引:1,自引:0,他引:1
已有结构的安全性的评估是关系到社会经济、安全的重大问题。本文作者从临界结构入手,以构件失效影响面积为参考,得到了计算构件重要性系数的简便方法,结合构件的可靠度提出了定性与定量结合的结构安全性综合评估方法。从工程实例来看,本文提出的方法简单实用,与现行的鉴定标准符合得比较好。 相似文献