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1.
Reading requires the orchestration of visual, attentional, language-related, and oculomotor processing constraints. This study replicates previous effects of frequency, predictability, and length of fixated words on fixation durations in natural reading and demonstrates new effects of these variables related to 144 sentences. Such evidence for distributed processing of words across fixation durations challenges psycholinguistic immediacy-of-processing and eye-mind assumptions. Most of the time the mind processes several words in parallel at different perceptual and cognitive levels. Eye movements can help to unravel these processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Sequential maximum a posteriori (SMAP) and the extraction and classification of homogeneous objects (ECHO), two spectral/spatial scene segmentation algorithms, were compared with traditional maximum likelihood (ML) estimation in a supervised classification of multispectral data. SMAP generalized better than both ECHO and ML. Significant differences were found in all mean class classification accuracies: SMAP>ECHO>ML 相似文献
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This paper describes the work done by the Autonomous Systems Lab of Ecole Polytechnique Federale de Lausanne (EPFL) on the global design of an unmanned solar airplane that can fly continuously over days and night. Part of the Sky-Sailor Project, a first prototype was designed and demonstrated to have very good flight characteristics. The prototype achieved an autonomous flight of five hours with its energy only from the sun. A lightweight control and navigation system was also designed for the aircraft. 相似文献
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Landgraf Ralf; Fischer Daniel; Eisenberg David 《Protein engineering, design & selection : PEDS》1999,12(11):943-951
Heregulins are members of the protein family of EGF-like growthand differentiation factors. The primary cell-surface targetsof heregulins are heterodimers of the EGF-receptor homolog HER2with either HER3 or HER4. We used a weighted evolutionary traceanalysis to identify structural features that distinguish theEGF-like domain (hrg) of heregulins from other members of theEGF family. In this analysis, each amino acid sequence is weightedaccording to its uniqueness and the variability in each positionis assigned by an amino acid substitution matrix. Conservedresidues in heregulin that are variable in other EGF-like domainsare considered possible specificity-conferring residues. Thisanalysis identifies two clusters of residues at the foot ofthe boot-shaped hrg domain. The residues in one cluster arerecruited from the N-terminus; those in the other are from the-loop region and show a weak sequence similarity to the N-terminalresidues at the opposite side of the boot. The remaining residueswith high conservation scores distribute themselves into thesetwo distinct surfaces on hrg. This pseudo-twofold symmetry andthe presence of two distinct interfaces may reflect the preferenceof hrg for heterodimeric versus homodimeric HER complexes. 相似文献
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Elastomer materials are used in a wide application range and subjected to different loading from which failure of the material results. Because this failure is caused by initiation and propagation of cracks, the application of fracture mechanics methods for the assessment of the material is obvious. A short summary of the methods of technical fracture mechanics including possibilities of determination of crack resistance curves is given. Vulcanizates on the basis of SBR 1500 with various sulfur and carbon black contents were investigated. For describing the crack initiation and crack propagation behavior, several fracture mechanics examination methods were applied. Tear‐analyzer results were used to assess the crack propagation behavior under fatigue‐like loading conditions. Furthermore, for the characterization of the crack resistance of the materials under impact‐like loading conditions, instrumented tensile‐impact tests were performed. To obtain information about the initiation and propagation of a stable crack, quasi‐static fracture mechanics tests were applied. The results of the several tests are discussed in dependence on sulfur and carbon black contents. We found a non‐monotonous behavior of the toughness as a function of carbon black loading. An explanation is given in connection with a percolation‐like transition in filler morphology on larger length scales.
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Ralf Dümpelmann Noel W. Cant David L. Trimm 《Applied catalysis. B, Environmental》1995,6(4):L291-L296
On-line infrared spectroscopy has been used to show that isocyanic acid, HNCO, is a substantial primary product of the reaction between NO, CO and H2 over a Pt/SiO2 catalyst. At 230°C it accounts for more than 40% of the CO converted. No isocyanic acid is seen when Al2O3 is placed downstream of Pt/SiO2, or when using a Pt/Al2O3 catalyst under the same conditions, due to rapid hydrolysis of HNCO on the alumina. Isocyanic acid may exist as a trace intermediate in automobile catalytic converters during their warm-up phase but it is unlikely to emerge from the pore system of aluminabased catalysts. 相似文献