全文获取类型
收费全文 | 377篇 |
免费 | 7篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 39篇 |
金属工艺 | 3篇 |
机械仪表 | 8篇 |
建筑科学 | 9篇 |
能源动力 | 6篇 |
轻工业 | 30篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 89篇 |
冶金工业 | 134篇 |
原子能技术 | 6篇 |
自动化技术 | 35篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 18篇 |
2012年 | 18篇 |
2011年 | 23篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 15篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 37篇 |
1997年 | 24篇 |
1996年 | 10篇 |
1995年 | 15篇 |
1994年 | 6篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1990年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1924年 | 1篇 |
1921年 | 1篇 |
排序方式: 共有384条查询结果,搜索用时 250 毫秒
11.
The measured photocurrents from two different p-n-junction silicon photodiodes at 170-? (73-eV) and at 8.34-? (1480-eV) light are presented. One is a standard extreme-UV photodiode fabricated on low resistivity silicon (70-100 Ω cm), and the other is fabricated on high-resistivity silicon (> 2 × 10(4) Ω cm). The photocurrents from the diode on high-resistivity silicon are at least an order of magnitude greater than the photocurrents from the diode on low-resistivity silicon when a reverse bias of 40 V is applied to each. This photocurrent enhancement is 15.4 ± 4 at 8.34 ? and 12.5 ± 2 at 170 ?. 相似文献
12.
13.
In this paper, we discuss convergence of a time window discretization method for the traveling salesman problem with time window constraints. This recently proposed discretization method leads to a lower bound to the minimization problem. Analysis shows that this method always guarantees convergence to the optimal solution. We also illustrate that the traditional method that gives feasible solutions does not always provide such a guarantee. 相似文献
14.
Driver distraction represents a significant problem in the public transport sector. Various methods exist for investigating distraction; however, the majority are difficult to apply within the context of naturalistic bus driving. This article investigates the nature of bus driver distraction at a major Australian public transport company, including the sources of distraction present, and their effects on driver performance, through the application of a novel framework of ergonomics methods. The framework represents a novel approach for assessing distraction in a real world context. The findings suggest that there are a number of sources of distraction that could potentially distract bus drivers while driving, including those that derive from the driving task itself, and those that derive from the additional requirements associated with bus operation, such as passenger and ticketing-related distractions. A taxonomy of the sources of bus driver distraction identified is presented, along with a discussion of proposed countermeasures designed to remove the sources identified or mitigate their effects on driver performance. 相似文献
15.
Modeling the efficacy of persuasive strategies for different gamer types in serious games for health
Rita Orji Julita Vassileva Regan L. Mandryk 《User Modeling and User-Adapted Interaction》2014,24(5):453-498
Persuasive games for health are designed to alter human behavior or attitude using various Persuasive Technology (PT) strategies. Recent years have witnessed an increasing number of such games, which treat players as a monolithic group by adopting a one-size-fits-all design approach. Studies of gameplay motivation have shown that this is a bad approach because a motivational approach that works for one individual may actually demotivate behavior in others. In an attempt to resolve this weakness, we conducted a large-scale study on 1,108 gamers to examine the persuasiveness of ten PT strategies that are commonly employed in persuasive game design, and the receptiveness of seven gamer personalities (gamer types identified by BrianHex) to the ten PT strategies. We developed models showing the receptiveness of the gamer types to the PT strategies and created persuasive profiles, which are lists of strategies that can be employed to motivate behavior for each gamer type. We then explored the differences between the models and, based on the results, proposed two approaches for data-driven persuasive game design. The first is the one-size-fits-all approach that will motivate a majority of gamers, while not demotivating any player. The second is the personalized approach that will best persuade a particular type of gamer. We also compiled a list of the best and the worst strategies for each gamer type. Finally, to bridge the gap between game design and PT researchers, we map common game mechanics to the persuasive system design strategies. 相似文献
16.
17.
18.
Temitope K. Egbelakin Suzanne Wilkinson Regan Potangaroa Jason Ingham 《Building Research & Information》2013,41(3):286-300
Seismic retrofit implementation has been a major challenge in many earthquake-prone cities. This paper examines why building owners are reluctant to adopt measures to reduce earthquake losses despite advancement in seismic design methods and the enactment of intervening legislative frameworks. A case study approach revealed the socio-behavioural barriers affecting seismic retrofit implementation. Significant barriers identified included the perception of earthquake risks, a lack of trust in seismic strengthening techniques and a lack of support for pro-social mitigation behaviours from public authorities. The findings suggest that a reappraisal of the policy implementation approach used by government agencies is required, and that greater attention should be given to seismic designs recommended by professionals and approved by regulatory authorities in order to earn building owners' trust regarding the efficacy of earthquake risk-reduction measures. La mise aux normes parasismiques des constructions existantes est un défi majeur dans de nombreuses villes sujettes aux tremblements de terre. Le présent article examine pourquoi les propriétaires d'immeubles sont peu disposés à adopter des mesures permettant de réduire les sinistres dus aux tremblements de terre en dépit des progrès réalisés dans les méthodes de conception parasismique et malgré la promulgation de cadres législatifs d'intervention. Une approche par étude de cas a mis en évidence les barrières sociocomportementales affectant la mise en ?uvre des normes parasismiques dans les immeubles existants. Ont été identifiés parmi ces obstacles importants la perception des risques de tremblements de terre, un manque de confiance dans les techniques de renforcement parasismique et un manque de soutien de la part des autorités publiques en faveur de comportements pro-sociaux permettant d'adoucir ces politiques. Les résultats obtenus suggèrent qu'il est nécessaire d'opérer une réévaluation de l'approche utilisée par les organismes publics pour mettre en ?uvre ces politiques, et qu'il devrait être porté une plus grande attention aux conceptions parasismiques recommandées par les professionnels et homologuées par les organismes de réglementation de façon à gagner la confiance des propriétaires d'immeubles, s'agissant de l'efficacité des mesures de réduction des risques liés aux tremblements de terre. Mots clés: propriétaires d'immeubles, prise de décision, immeubles sujets aux tremblements de terre, politique publique, perception des risques, mise aux normes parasismiques, comportement des parties prenantes 相似文献
19.
20.
Mary-Keara Boss Remy Watts Lauren G. Harrison Sophie Hopkins Lyndah Chow Erin Trageser Carina Easton Susan M. LaRue Daniel Regan Mark W. Dewhirst Steven Dow 《International journal of molecular sciences》2022,23(2)
Stereotactic body radiotherapy (SBRT) is known to induce important immunologic changes within the tumor microenvironment (TME). However, little is known regarding the early immune responses within the TME in the first few weeks following SBRT. Therefore, we used the canine spontaneous tumor model to investigate TME responses to SBRT, and how local injection of immune modulatory antibodies to OX40 and TLR 3/9 agonists might modify those responses. Pet dogs with spontaneous cancers (melanoma, carcinoma, sarcoma, n = 6 per group) were randomized to treatment with either SBRT or SBRT combined with local immunotherapy. Serial tumor biopsies and serum samples were analyzed for immunologic responses. SBRT alone resulted at two weeks after treatment in increased tumor densities of CD3+ T cells, FoxP3+ Tregs, and CD204+ macrophages, and increased expression of genes associated with immunosuppression. The addition of OX40/TLR3/9 immunotherapy to SBRT resulted in local depletion of Tregs and tumor macrophages and reduced Treg-associated gene expression (FoxP3), suppressed macrophage-associated gene expression (IL-8), and suppressed exhausted T cell-associated gene expression (CTLA4). Increased concentrations of IL-7, IL-15, and IL-18 were observed in serum of animals treated with SBRT and immunotherapy, compared to animals treated with SBRT. A paradoxical decrease in the density of effector CD3+ T cells was observed in tumor tissues that received combined SBRT and immunotherapy as compared to animals treated with SBRT only. In summary, these results obtained in a spontaneous large animal cancer model indicate that addition of OX40/TLR immunotherapy to SBRT modifies important immunological effects both locally and systemically. 相似文献