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排序方式: 共有1261条查询结果,搜索用时 15 毫秒
61.
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Dultsev FN Speight RE Fiorini MT Blackburn JM Abell C Ostanin VP Klenerman D 《Analytical chemistry》2001,73(16):3935-3939
We show that it is possible to detect specifically adsorbed bacteriophage directly by breaking the interactions between proteins displayed on the phage coat and ligands immobilized on the surface of a quartz crystal microbalance (QCM). This is achieved through increasing the amplitude of oscillation of the QCM surface and sensitively detecting the acoustic emission produced when the bacteriophage detaches from the surface. There is no interference from nonspecifically adsorbed phage. The detection is quantitative over at least 5 orders of magnitude and is sensitive enough to detect as few as 20 phage. The method has potential as a sensitive and low-cost method for virus detection. 相似文献
63.
Hao Zhang T.R. Blackburn B.T. Phung D. Sen 《Dielectrics and Electrical Insulation, IEEE Transactions on》2007,14(1):3-14
Medium and high voltage power cables are widely used in the electrical industry with substantial growth over the last 20-30 years ago, particular in the use of XLPE insulated systems. Ageing of the cable insulation is becoming an increasing problem that requires development of reliable methods for on-line condition assessment. For insulation condition assessment of MV and HV cables, partial discharge (PD) monitoring is one of the most effective techniques. However on-site and on-line PD measurements are affected by electromagnetic interference (EMI) that makes sensitive PD detection very difficult, if not impossible. This paper describes implementation of wavelet transform techniques to reject noise from on-line partial discharge measurements on cables. A new wavelet threshold determination method is proposed with the technique. With implementation of this novel de-noising method, PD measurement sensitivity has been greatly improved. In addition, a full AC cycle data recovery can be achieved instead of focusing only on recovering individual PD pulses. Other wavelet threshold de-noising methods are discussed and examined under a noisy environment to compare their performance with the new method proposed here. The method described here has been found to be superior to the other wavelet-based methods 相似文献
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Bracken presents a serious environmental problem in many regions of the world and remote sensing offers the potential of monitoring the invasion and management of this plant. This study evaluates this potential by reporting the results of an investigation of the relationships between the biophysical properties of a bracken canopy and its spectral reflectance and how such relationships are effected by view angle. An experiment was carried out through the bracken growing season at sites in West Sussex, UK. In the principal plane of the Sun, red reflectance becomes lower and relatively less variable with view angle as the canopy develops, while near-infrared reflectance increases and becomes relatively more variable with view angle. As Leaf Area Index (LAI) increases, the variability of the Normalized Difference Vegetation Index (NDVI) with view angle decreases, while the simple ratio vegetation index (SR) behaves in almost the opposite manner. Polar plots, illustrating full directional reflectance distributions, reveal that as the canopy develops the hot spot in red reflectance at the retro-solar angle diminishes, to be replaced by enhanced red reflectance at high zenith angles in the forward-scatter direction. Near-infrared reflectance behaves very differently, as a hot spot at the retro-solar angle becomes more pronounced as the canopy grows. The angular distribution of NDVI and SR varies markedly over the growing season, however both indices are well correlated with canopy biophysical properties for most view angles sampled, apart from the extreme off-nadir. Red edge position was largely insensitive to view angle, but had a good correlation with LAI, as did percenage reflectance at the red edge position. 相似文献
66.
Yuqian Zhang Stephen Westland Vien Cheung Stephen M Burkinshaw Richard S Blackburn 《Coloration Technology》2009,125(6):357-365
A low‐cost and environmental‐friendly direct dye‐based ink‐jet printing system was developed. A novel ink‐jet pretreatment method was employed, in which the cationic fixing agent, Matexil FC‐ER, was applied as the colourless fixing ink and applied only on image areas of the fabric by ink‐jet printer. It was found that this new pretreatment method could more effectively enhance the colour strength and improve the wash fastness (greyscale ≥ 3) when compared with traditional exhaust application. The cross‐staining of non‐image areas of fabric was also apparently decreased using this new method. The light fastness of ink‐jet pretreated samples was slightly reduced as the presence of Matexil FC‐ER made dyes more sensitive to light. 相似文献
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PURPOSE: Organized interscholastic athletics are an integral part of the educational program at almost every school level. With this growing popularity of sports and their inclusion in more public school programs, it becomes increasingly apparent that additional consideration must be given to the injury problem associated with sport. The North Carolina High School Athletic Injury Study (NCHSAIS) was undertaken to identify patterns of injury among male and female athletes in North Carolina high schools participating in any of 12 sports. Specific aims are to measure the incidence, severity and etiology of injuries; to determine the relationship of demographic factors and protective equipment, exposure to play, and school characteristics to injuries; to study the relationship of coaches' training and experience to injury occurrence; and to compare the incidence and severity of injury among female and male athletes in the same or comparable sports. METHODS: A two-stage cluster sample of 100 high schools in North Carolina was selected for this 4-yr prospective study. RESULTS: Participation by the initial sample or a random replacement was achieved for 91 of the 100 schools. Nonresponse occurred at multiple levels of the sample for this study, and the weekly participation form posed the greatest respondent burden. CONCLUSIONS: The NCHSIAS offers a successful methodology for addressing sports injuries. In this paper we describe the design, methodology, and implementation issues that emerge in conducting a large scale epidemiological study in a population of high school athletes. 相似文献
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Patrick L Jacobs Erica R Goldstein Will Blackburn Ihsan Orem John J Hughes 《Journal of the International Society of Sports Nutrition》2009,6(1):9-11