全文获取类型
收费全文 | 357篇 |
免费 | 10篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 16篇 |
金属工艺 | 6篇 |
机械仪表 | 5篇 |
建筑科学 | 18篇 |
能源动力 | 10篇 |
轻工业 | 82篇 |
水利工程 | 7篇 |
无线电 | 54篇 |
一般工业技术 | 37篇 |
冶金工业 | 96篇 |
原子能技术 | 1篇 |
自动化技术 | 33篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 13篇 |
2009年 | 16篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 13篇 |
2005年 | 13篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 10篇 |
2001年 | 16篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 37篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 15 毫秒
1.
A case of traumatic extracranial vertebral arterial dissection leading to vertebrobasilar thrombosis and respiratory compromise requiring mechanical ventilation was managed with intraarterial thrombolysis and stenting of the vertebral intimal dissection. In contrast to similar, previously reported cases, this critically ill patient made a full recovery, returning to his job as a secondary school teacher. 相似文献
2.
ST O'Sullivan GT McGreal A Lyons L Burke JG Geoghegan MP Brady 《Canadian Metallurgical Quarterly》1994,47(9):851-852
A case of histologically confirmed Paget's disease of the breast in a 72 year old man, without underlying breast carcinoma, is reported. This report raises questions about the pathogenesis of this condition and suggests that Paget's disease is an independent, intraepidermal carcinoma rather than a direct extension of intraductal carcinoma of the breast to the nipple and areola. 相似文献
3.
This work demonstrates that for constant oxide reliability stresses in the Fowler-Nordheim regime a low initial rate of charge trapping/detrapping results in long times to breakdown. It was found for MOS gate oxides that when the initial trapping has been completed at low fields times to breakdown enhance. Depending on the stress sequence measurement results can vary significantly which is of great relevance for correct oxide lifetime predictions. 相似文献
4.
A fast sinc function gridding algorithm for fourier inversion in computer tomography 总被引:9,自引:0,他引:9
O'Sullivan JD 《IEEE transactions on medical imaging》1985,4(4):200-207
The Fourier inversion method for reconstruction of images in computerized tomography has not been widely used owing to the perceived difficulty of interpolating from polar or other measurement grids to the Cartesian grid required for fast numerical Fourier inversion. Although the Fourier inversion method is recognized as being computationally faster than the back-projection method for parallel ray projection data, the artifacts resulting from inaccurate interpolation have generally limited application of the method. This paper presents a computationally efficient gridding algorithm which can be used with direct Fourier transformation to achieve arbitrarily small artifact levels. The method has potential for application to other measurement geometries such as fan-beam projections and diffraction tomography and NMR imaging. 相似文献
5.
Leopoldina Fortunati Mauro Sarrica John O'Sullivan Aukse Balcytiene Halliki Harro-Loit Phil Macgregor Nayia Roussou Ramón Salaverría Federico de Luca 《Journal of Computer-Mediated Communication》2009,14(4):928-963
This study investigates how European journalists evaluate the changes that have occurred in their profession since the Internet has been integrated in newsrooms. How do journalists perceive the features and innovations associated with the Internet? What are the principal changes in the profession? Do practitioners believe that the quality of journalism has been raised or lowered? To answer to these research questions, we carried out a survey across 11 European countries–Cyprus, Estonia, Finland, Greece, Ireland, Italy, Lithuania, United Kingdom, Slovenia, Spain, Sweden–of 239 journalists, working for 40 of the most‐read print/online news outlets in these countries. The survey shows that the opportunity to use the Internet to reinforce the social functions of journalism has not been fully recognised. 相似文献
6.
Semantic Web computing in industry 总被引:1,自引:0,他引:1
John G. Breslin Author Vitae David O'Sullivan Author VitaeAuthor Vitae Laurentiu Vasiliu Author Vitae 《Computers in Industry》2010,61(8):729-741
The Semantic Web has attracted significant attention during the last decade. On the one hand, many research groups have changed their focus towards Semantic Web research and research funding agencies particularly in Europe have explicitly mentioned Semantic Web in their calls for proposals. On the other hand, industry has also begun to watch developments with interest and a number of large companies have started to experiment with Semantic Web technologies to ascertain if these new technologies can be leveraged to add more value for their customers or internally within the company, while there are already several offers of vendors of Semantic Web solutions on the market. The essence of the Semantic Web is to structure Web-based information to make it more interoperable, machine-readable and thereafter to provide a means to relate various information concepts more easily and in a reusable way. The Semantic Web acts as an additional layer on the top of the Web, and is built around explicit representations of information concepts and their relationships such as ontologies and taxonomies. Furthermore, Semantic Web technologies are not only valuable on an open environment like the Web, but also in closed systems such as in industrial settings. Hence, these technologies can be efficiently deployed for domains including Web Services, Enterprise Application Integration, Knowledge Management and E-Commerce, fulfilling existing gaps in current applications. This paper focuses on this synthesis between Semantic Web technologies and systems problems within industrial applications. There will be a short review of Semantic Web standards, languages and technologies followed by a more detailed review of applications of Semantic Web computing in industry. The paper covers theoretical considerations as well as use cases and experience reports on the topic, and we also present some current challenges and opportunities in the domain. 相似文献
7.
The aim of the study was to examine the pattern of the change in discomfort for combined wrist deviation and forearm rotation as joint angles increased away from neutral in a repetitive task. There were five levels of wrist deviation (neutral, 35% and 55% of the range of motion (ROM) in radial and ulnar deviation) and five levels of forearm rotation (neutral, 30% and 60% of the ROM in pronation and supination). Twenty-five participants performed a repetitive flexion task with a force of 10 N +/- 1 N at a frequency of 15 exertions per min, with replication after 1 week for six of the participants. A visual analogue scale was used for recording the discomfort scores. Repeated measures analysis of covariance with the Greenhouse-Geisser correction, where necessary, was used on transformed values of the discomfort scores. Grip test endurance time at 50% of maximum voluntary contraction was included as a covariate. Wrist deviation (p = 0.007) and forearm rotation (p = 0.001) were found to have significant effects. Interactions of the main factors were not significant and nor was the covariate. Quadratic regression equations were derived and were used to generate iso-discomfort contours, which show a useful area of low discomfort around the central neutral zone of wrist postures, but with steep increases in discomfort at the extreme combinations of wrist ulnar/radial deviation with forearm pronation/supination. Discomfort equations and contours, showing wrist and forearm postures, which are either acceptable or potentially injurious, are useful for the design of industrial tools, machine controls and workspaces. Reference to these can help to reduce the risk of musculoskeletal injury associated with the tasks or tools by avoiding poor postures with unacceptable deviations from neutral posture. 相似文献
8.
Lumbar posture is commonly assessed in non-specific chronic low back pain (NSCLBP), although quantitative measures have mostly been limited to laboratory environments. The BodyGuard? is a spinal position monitoring device that can monitor posture in real time, both inside and outside the laboratory. The reliability of this wireless device was examined in 18 healthy participants during usual sitting and forward bending, two tasks that are commonly provocative in NSCLBP. Reliability was determined using intraclass correlation coefficients (ICC), the standard error of measurement (SEM), the mean difference and the minimal detectable change (MDC90). Between-day ICC values ranged from 0.84 to 0.87, with small SEM (5%), mean difference (<9%) and MDC90 (<14%) values. Inter-rater ICC values ranged from 0.91 to 0.94, with small SEM (4%), mean difference (6%) and MDC90 (9%) values. Between-day and inter-rater reliability are essential requirements for clinical utility and were excellent in this study. Further studies into the validity of this device and its application in clinical trials in occupational settings are required. STATEMENT OF RELEVANCE: A novel device that can analyse spinal posture exposure in occupational settings in a minimally invasive manner has been developed. This study established that the device has excellent between-day and inter-rater reliability in healthy pain-free subjects. Further studies in people with low back pain are planned. 相似文献
9.
O'Sullivan F 《IEEE transactions on medical imaging》1993,12(3):399-412
Two methodologies for fitting radiotracer models on a pixel-wise basis to PET data are considered. The first method does parameter optimization for each pixel considered as a separate region of interest. The second method also does pixel-wise analysis but incorporates an additive mixture representation to account for heterogeneity effects induced by instrumental and biological blurring. Several numerical and statistical techniques including cluster analysis, constrained nonlinear optimization, subsampling, and spatial filtering are used to implement the methods. A computer simulation experiment, modeling a standard F-18 deoxyglucose (FDG) imaging protocol using the UW-PET scanner, is conducted to evaluate the statistical performance of the parametric images obtained by the two methods. The results obtained by mixture analysis are found to have substantially improved mean square error performance characteristics. The total computation time for mixture analysis is on the order of 0.7 s/pixel on a 16 MIPS workstation. This results in a total computation time of about 1 h per slice for a typical FDG brain study. 相似文献
10.
The purpose of this study was to develop and test a physical ergonomics assessment approach for medical device handles. The method assesses wrist posture and force of exertion simultaneously by task element. Electrogoniometers and EMG sensors were connected through a data acquisition module for synchronization with video recordings of trials. Task analysis of video recordings were performed offline with Observer XT software. Average posture and force data across several repetitions of individual task elements were calculated and presented in a format suitable for informing product designers of specific issues during a test trial. A handle comfort questionnaire is proposed to survey subjective responses. The evaluation approach was applied to an endoscope needle in sampling a biopsy from the stomach wall using a gastrointestinal track simulator with ten physician surrogates. The results showed that for all task elements the wrist was in extension (33(°)-45(°)). Peak muscle forces ranged from 28% to 68% MVC across the three muscles studied. Muscle peak forces were above ACGIH HAL maximum threshold limits for four of the seven task elements, and above the action limit for all seven task elements for two muscles. The handle comfort questionnaire data also supported the high muscle force findings, and also on force distribution on the handle due to contact stresses. This combined approach could be used to collect and report detailed early stage ergonomics data from user trials on patient care simulators. The approach is proposed for use by medical device designers at the design stage of new products using prototypes, but it could also be used on existing products with real patients. 相似文献