全文获取类型
收费全文 | 919篇 |
免费 | 88篇 |
国内免费 | 94篇 |
专业分类
电工技术 | 114篇 |
综合类 | 72篇 |
化学工业 | 39篇 |
金属工艺 | 14篇 |
机械仪表 | 44篇 |
建筑科学 | 193篇 |
矿业工程 | 19篇 |
能源动力 | 39篇 |
轻工业 | 53篇 |
水利工程 | 36篇 |
石油天然气 | 16篇 |
武器工业 | 3篇 |
无线电 | 70篇 |
一般工业技术 | 43篇 |
冶金工业 | 128篇 |
原子能技术 | 2篇 |
自动化技术 | 216篇 |
出版年
2024年 | 4篇 |
2023年 | 14篇 |
2022年 | 14篇 |
2021年 | 34篇 |
2020年 | 41篇 |
2019年 | 28篇 |
2018年 | 37篇 |
2017年 | 39篇 |
2016年 | 29篇 |
2015年 | 52篇 |
2014年 | 65篇 |
2013年 | 61篇 |
2012年 | 67篇 |
2011年 | 79篇 |
2010年 | 62篇 |
2009年 | 65篇 |
2008年 | 57篇 |
2007年 | 62篇 |
2006年 | 51篇 |
2005年 | 33篇 |
2004年 | 24篇 |
2003年 | 34篇 |
2002年 | 21篇 |
2001年 | 28篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1987年 | 4篇 |
1977年 | 1篇 |
1972年 | 1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 | 2篇 |
排序方式: 共有1101条查询结果,搜索用时 10 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.
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
3.
4.
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
5.
6.
网络信息分级是保障网络信息内容安全的重要手段。主要构建了网络信息资源分级体系框架六元组模型,分析了相关组成元素的内容,以适应不同行业应用。 相似文献
7.
《Expert systems with applications》2014,41(16):7235-7247
Deciding whether borrowers can fulfill their obligations is a major issue for financial institutions, and while various credit rating models have been developed to help achieve this, they cannot reflect the domain knowledge of human experts. This paper proposes a new rating model based on a support vector machine with monotonicity constraints derived from the prior knowledge of financial experts. Experiments conducted on real-world data sets show that the proposed method, not only data driven but also domain knowledge oriented, can help correct the loss of monotonicity in data occurring during the collecting process, and performs better than the conventional counterpart. 相似文献
8.
Morten Hertzum Rolf Molich Niels Ebbe Jacobsen 《Behaviour & Information Technology》2014,33(2):144-162
Usability evaluation is essential to user-centred design; yet, evaluators who analyse the same usability test sessions have been found to identify substantially different sets of usability problems. We revisit this evaluator effect by having 19 experienced usability professionals analyse video-recorded test sessions with five users. Nine participants analysed moderated sessions; 10 participants analysed unmoderated sessions. For the moderated sessions, participants reported an average of 33% of the problems reported by all nine of these participants and 50% of the subset of problems reported as critical or serious by at least one participant. For the unmoderated sessions, the percentages were 32% and 40%. Thus, the evaluator effect was similar for moderated and unmoderated sessions, and it was substantial for the full set of problems and still present for the most severe problems. In addition, participants disagreed in their severity ratings. As much as 24% (moderated) and 30% (unmoderated) of the problems reported by multiple participants were rated as critical by one participant and minor by another. The majority of the participants perceived an evaluator effect when merging their individual findings into group evaluations. We discuss reasons for the evaluator effect and recommend ways of managing it. 相似文献
9.
10.
可持续发展战略得在世界各国的认可,以低排放、低消耗、低污染为特征的经济发展模式,节能减排是其重要的组成部分和内在要求。从我国实行节能减排的必要性出发,结合银行支持节能减排的具体措施,在银行信用评级体系中加入节能减排指标,进而建立一个新型绿色中小型企业信用评级体系。 相似文献