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81.
We examined whether the perception of the colorfulness of an image is influenced by the adaptation of the visual system to natural and shuffled images with different degrees of saturation. In the experiment, observers first became adapted to several images with different levels of saturation and then their colorfulness perception of a test image was measured. The results show that their perception of colorfulness was influenced by their adaptation to the saturation of images. The effect was stronger following adaptation to natural images than to images consisting of a shuffled collage of randomized color blocks, which suggests that the naturalness of the spatial structure of an image affects the strength of the effect.  相似文献   
82.
Fe-substituted Li2MnO3 including a monoclinic layered rock-salt structure (C2/m), (Li1+x(FeyMn1−y)1−xO2, 0 < x < 1/3, 0.1 ≤ y ≤ 0.5) was prepared by coprecipitation-hydrothermal-calcination method. The sample was assigned as two-phase composite structure consisting of the cubic rock-salt () and monoclinic ones at high Fe content above 30% (y ≥ 0.3), while the sample was assigned as a monoclinic phase (C2/m) at low Fe content less than 20%. In the monoclinic Li2MnO3-type structure, the Fe ion tends to substitute a Li (2b) site, which corresponds to a center position of Mn4+ hexagonal network in Mn-Li layer. The electrochemical properties including discharge characteristics under high current density (<3600 mA g−1 at 30 °C) and low temperature (<−20 °C at 40 mA g−1) were severely affected by chemical composition (Fe content and Li/(Fe + Mn) ratio), crystal structure (monoclinic phase content) and powder property (specific surface area). Under the optimized Fe content (0.2 < y < 0.4), the Li/sample cells showed high initial discharge capacity (240-300 mAh g−1) and energy density (700-950 mWh g−1) between 1.5 and 4.8 V under moderate current density, 40 mA g−1 at 30 °C. Results suggest that Fe-substituted Li2MnO3 would be a non-excludable 3 V positive electrode material.  相似文献   
83.
The developing views of the purposes of school learning (PSLs) and related achievement among immigrant Chinese preschoolers and their European American (EA) age-mates were examined. Both culture and socioeconomic status (SES) were considered simultaneously, an often neglected research approach to studying Asian children. One hundred and fifty 4-year-olds—50 each of middle-class Chinese (CHM), low-income Chinese (CHL), and EA children—completed 2 story beginnings about school and were also tested for their language and math achievement. Results showed that 4-year-olds held sophisticated PSLs, ranging from intellectual to social and affect benefits. Large cultural and SES differences also emerged. CHM children mentioned more adult expectation and seriousness of learning than EA children who expressed more positive affect for self and compliance with adults. CHL children mentioned fewest PSLs. Achievement scores for oral expression of both immigrant groups were significantly lower than those of EA children despite similar reading and math achievement. Controlling for culture and SES, the authors found that children's articulated intellectual, but not other purposes, uniquely predicted their achievement in all tested domains. Cultural and SES influences on immigrant children are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
84.
Silica (SiO2)‐crosslinked polystyrene (PS) particles possessing photofunctional N,N‐diethyldithiocarbamate (DC) groups on their surface were prepared by the free‐radical emulsion copolymerization of a mixture of SiO2 (diameter = 20 nm), styrene, divinyl benzene, 4‐vinylbenzyl N,N‐diethyldithiocarbamate (VBDC), and 2‐hydroxyethyl methacrylate with a radical initiator under UV irradiation. In this copolymerization, the inimer VBDC had the formation of a hyperbranched structure by a living radical mechanism. The particle sizes of such core–shell structures [number‐average particle diameter (Dn) = 35–40 nm] were controlled by the variation of the feed amounts of the monomers and surfactant, or emulsion system. The size distributions were relatively narrow (weight‐average particle diameter/Dn ≈ 1.05). These particles had DC groups on their surface. Subsequently, poly(methyl methacrylate) brush encapsulated SiO2 particles were synthesized by the grafting from a photoinduced atom transfer radical polymerization approach of methyl methacrylate initiated by SiO2‐crosslinked PS particles as a macroinitiator. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   
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A large volume injection head-space GC method was established for measuring low levels of residual methanol and ethanol in licorice extract used a food additive. A vial was kept at 50 degrees C in the oven of the head-space sampler. Injection of the head-space gas for 0.75 min into a Poraplot Q GC column with a initial oven temperature of 35 degrees C, enabled the determination of low levels (5 micrograms/g) of methanol and ethanol. The standard deviations for five rounds of analysis of methanol and ethanol in licorice extracts were between 0.82 and 2.97. Methanol was found in 6 samples out of 9 collected in 1999, at concentrations exceeding 50 micrograms/g, the limit set by the Japanese Government, established in 1999 and coming into force on April 1, 2000. The highest concentration reached 10,000 micrograms/g. Methanol at a concentration exceeding 50 micrograms/g was found in 2 out of 9 samples collected in 2000. The highest concentration was 270 micrograms/g.  相似文献   
90.
Antimicrobial activity of nutmeg against Escherichia coli O157   总被引:2,自引:0,他引:2  
We examined the difference between Escherichia coli O157 and non-pathogenic E. coli in their tolerance to spices. Various spices (5 g each) were homogenized at 25 degrees C for 10 min with 5 ml of 70% ethyl alcohol, and the supernatant solutions obtained by centrifugation were used as spice extracts. When the E. coli strains were incubated with each spice extract at concentrations of 0.01% and 0.1%, a noteworthy difference was observed between the O157 and non-pathogenic strains in their tolerance to nutmeg. The populations of the non-pathogenic strains could not be reduced, but those of the O157 strains were remarkably reduced. Antibacterial activity by the nutmeg extract was also found against the enteropathogenic E. coli O111, but not against enterotoxigenic (O6 and O148) and enteroinvasive (O29 and O124) E. coli. When we examined the antibacterial effect of volatile oils in nutmeg on the O157 and non-pathogenic E. coli strains, all O157 strains tested were found to be more sensitive to beta-pinene than non-pathogenic E. coli strains.  相似文献   
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