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251.
This paper examines the extent to which firms perceive different dimensions of proximity to be important for the formation of their interactions with universities. Furthermore, it investigates whether the importance of the different types of proximities varies depending on the type of interaction—be it about knowledge exploration, knowledge exploitation, competence enhancement, advice-seeking or marketing. Using data from a survey of 1,200 Norwegian firms, we find that most managers believe cognitive, institutional, social and geographical proximity were important for their decision to collaborate with university partners and that the importance of proximity types varies depending on the contents of the interaction. 相似文献
252.
253.
This paper analyses how the formation of collaboration networks affects firm-level innovation by applying the ‘Goldilocks principle’. The ‘Goldilocks principle’ of optimal distance in innovation networks postulates that the best firm-level innovation results are achieved when the partners involved in the network are located at the ‘right’ distance, i.e. ‘not too close and not too far’ from one another, across non-geographical proximity dimensions. This principle is tested on a survey of 542 Norwegian firms conducted in 2013, containing information about firm-level innovation activities and key innovation partners. The results of the ordinal logit regression analysis substantiate the Goldilocks principle, as the most innovative firms are found among those that collaborate with partners at medium levels of proximity for all non-geographical dimensions. The analysis also underscores the importance of the presence of a substitution–innovation mechanism, with geographical distance problems being compensated by proximity in other dimensions as a driver of innovation, while there is no support for a potential overlap–innovation mechanism. 相似文献
254.
Brominated flame retardants in polar bears (Ursus maritimus) from Alaska, the Canadian Arctic, East Greenland, and Svalbard 总被引:1,自引:0,他引:1
Muir DC Backus S Derocher AE Dietz R Evans TJ Gabrielsen GW Nagy J Norstrom RJ Sonne C Stirling I Taylor MK Letcher RJ 《Environmental science & technology》2006,40(2):449-455
Polybrominated diphenyl ethers (PBDEs) were determined in adipose tissue of adult and subadult female polar bears sampled between 1999 and 2002 from sub-populations in Arctic Canada, eastern Greenland, and Svalbard, and in males and females collected from 1994 to 2002 in northwestern Alaska. Only 4 congeners (BDE47, 99, 100, and 153) were consistently identified in all samples. BDE47 was the major PBDE congener representing from 65% to 82% of the sum (sigma) PBDEs. Age was not a significant covariate for individual PBDEs or sigmaPBDE. Higher proportions of BDE 99, 100, and 153 were generally found in samples from the Canadian Arctic than from Svalbard or the Bering-Chukchi Sea area of Alaska. Geometric mean sigmaPBDE concentrations were highest for female polar bear fat samples collected from Svalbard (50 ng/g lipid weight (lw)) and East Greenland (70 ng/g lw). Significantly lower sigmaPBDE concentrations were found in fat of bears from Canada and Alaska (means ranging from 7.6 to 22 ng/g lw). 相似文献
255.
Sarah Bernardis Bonna K. Newman Marisa Di Sabatino Sirine C. Fakra Mariana I. Bertoni David P. Fenning Rune B. Larsen Tonio Buonassisi 《Progress in Photovoltaics: Research and Applications》2012,20(2):217-225
Using synchrotron‐based analytical microprobe techniques, we determine micrometer‐scale elemental composition, spatial distribution, and oxidation state of impurities in raw feedstock materials used in the photovoltaic industry. Investigated Si‐bearing compounds are pegmatitic quartz, hydrothermal quartz, and quartzite. Micrometer‐scale clusters containing Fe, Ti, and/or Ca are frequently observed at structural defects in oxidized states and in bulk concentrations equivalent to inductively coupled plasma mass spectroscopy measurements. Investigated C‐bearing compounds are pine wood, pine charcoal, and eucalyptus charcoal. Clustered metals are observed only in the charcoal samples. Impurity clustering implies that industrial processing could be adapted to take advantage of this “natural gettering” phenomenon, expanding the usable range of raw feedstock materials to dirtier, cheaper, and more abundant ones, currently underexploited for solar‐grade silicon production. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献