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排序方式: 共有271条查询结果,搜索用时 187 毫秒
71.
Erra Ugo Scanniello Giuseppe Colonnese Valerio 《Multimedia Tools and Applications》2018,77(19):25077-25107
Multimedia Tools and Applications - In this paper, we describe our experience with the design of an augmented reality dressing room in which 3D models of a dress are overlaid with a color image... 相似文献
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Alessio Fossati Martina Di Ferdinando Ugo Bardi Andrea Scrivani Carlo Giolli 《Journal of Thermal Spray Technology》2012,21(2):314-324
CoNiCrAlY coatings were produced by means of the vacuum plasma spraying (VPS) process onto CMSX-4 single crystal nickel superalloy
disk substrates. As-sprayed samples were annealed at high temperatures in low vacuum. Three kinds of finishing processes were
carried out, producing three types of samples: as-sprayed, mechanically smoothed by grinding, ground and PVD coated by using
aluminum targets in an oxygen atmosphere. Samples were tested under isothermal conditions, in air, at 1000 °C, and up to 5000 h.
Morphological, microstructural and compositional analyses were performed on the coated samples in order to assess the high
temperature oxidation behavior provided by the three different surface finishing processes. Several differences were observed:
grinding operations decrease the oxidation resistance, whereas the PVD process can increase the performances over longer time
with respect of the as-sprayed samples. 相似文献
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Sesana L Fumagalli M Carnevale M Polla G Facchini U Colombo A Tunesi A De Capitani L Rusconi R 《Radiation protection dosimetry》2006,118(3):337-344
Monitoring of the gamma radiation in Valle del Cervo Pluton was performed by determining U and Th contents in the main rock types cropping out over the entire area and pertaining to the granitic complex, syenitic complex and monzonitic complex. In particular, syenitic rocks were largely used as building and ornamental materials (e.g. Sienite della Balma). All the samples are fresh and do not present joints or fractures filled with U minerals. In the crushed samples the activity of uranium varies from 346 to 764 Bq/kg. Concentration of thorium varies from 202 to 478 Bq/kg. For all the analysed rocks uranium activity is higher than thorium one. The lowest value of radioactive concentration is referred to rocks of the granitic complex. The most active rocks are syenites. The data confirm the high activities of Valle del Cervo rock types, strongly connected with high K content of the source magma (geochemical signature); on the contrary, the activity seems to be not related to the location of the samples. 相似文献
77.
Fabio Borbone Ugo Caruso Rosita Diana Barbara Panunzi Antonio Roviello Marco Tingoli Angela Tuzi 《Organic Electronics》2009,10(1):53-60
Two new trifunctional thiophene based dyes suited for crosslinking were synthesised from the same structural core, i.e. 4-[[5-[(4-nitrophenyl)azo]-2-thienyl]azo]benzenamine. Crystal structure and second order nonlinear optical properties were determined on a related difunctional dye that can be considered as a representative and simplified model of the trifunctional compounds, determining on it the μβ value of 4950 × 10?48 esu (6111 × 10?80 C2 m4 V?2).The presence of three acrylic or hydroxyl functional groups in the dyes allowed to incorporate the chromophoric fragment into two different kinds of crosslinked materials possessing “frozen” long-lasting dipole order. The traditional guest-host approach used for one of them was exceeded by covalently anchoring the chromophore to a functionalised polymer in a three-dimensional unique network. In this way a promising NLO active material was obtained. The value of the d33 coefficient (determined by SHG measurement using the Maker fringe technique) was 11 pm/V for the poled/crosslinked film. Very good thermal and temporal stability of the chromophore poling-induced dipole alignment was attained. 相似文献
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Romain Fleurier Jean‐Sébastien Lauret Ugo Lopez Annick Loiseau 《Advanced functional materials》2009,19(14):2219-2223
Diameter separation of single‐walled carbon nanotubes is achieved via the density gradient ultracentrifugation process. Statistical analysis of the separated samples is performed using high‐resolution transmission electron microscopy (HRTEM). The evolution of the diameter distribution with respect to the gradient density is extracted by analyzing hundreds of HRTEM images, and the results are found to be consistent with those estimated by UV–vis–IR spectroscopy. The efficiency of the separation process can be quantitatively characterized by the standard deviation of the diameter distribution, which is determined from the TEM analyses. This particular study indicated that for electric arc nanotubes dispersed in sodium cholate, diameter sorting is more efficient in the upper part of the gradient. 相似文献
79.
We consider the basic problem of searching for an unknown m-bit number by asking the minimum possible number of yes–no questions, when up to a finite number e of the answers may be erroneous. In case the (i+1)th question is adaptively asked after receiving the answer to the ith question, the problem was posed by Ulam and Rényi and is strictly related to Berlekamp's theory of error correcting communication with noiseless feedback. Conversely, in the fully non-adaptive model when all questions are asked before knowing any answer, the problem amounts to finding a shortest e-error correcting code. Let qe(m) be the smallest integer q satisfying Berlekamp’s bound
. Then at least qe(m) questions are necessary, in the adaptive, as well as in the non-adaptive model. In the fully adaptive case, optimal searching strategies using exactly qe(m) questions always exist up to finitely many exceptional m's. At the opposite non-adaptive case, searching strategies with exactly qe(m) questions—or equivalently, e-error correcting codes with 2m codewords of length qe(m)—are rather the exception, already for e=2, and are generally not known to exist for e>2. In this paper, for each e>1 and all sufficiently large m, we exhibit searching strategies that use a first batch of m non-adaptive questions and then, only depending on the answers to these m questions, a second batch of qe(m)−m non-adaptive questions. These strategies are automatically optimal. Since even in the fully adaptive case, qe(m)−1 questions do not suffice to find the unknown number, and qe(m) questions generally do not suffice in the non-adaptive case, the results of our paper provide e fault tolerant searching strategies with minimum adaptiveness and minimum number of tests. 相似文献
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