Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constanc...Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.展开更多
Purpose: The study investigated the impact of dietary habits, specifically soda, milk kefir, water kefir, almond milk, and distilled water (control) consumption, on the microhardness of gingiva-coloured composite and ...Purpose: The study investigated the impact of dietary habits, specifically soda, milk kefir, water kefir, almond milk, and distilled water (control) consumption, on the microhardness of gingiva-coloured composite and acrylic denture bases. Methods: Materials included gingiva-coloured composite (Fusion Universal G1), acrylic (Imicryl), and subdivided Procryla group. Subgroups comprised 15 and 30-minute heat polymerized (Pro15, Pro30), and 1 wt% (Pro1Z) and 3 wt% (Pro3Z) zirconium added groups. Immersed in beverages for 1, 7, and 14 days, pH and microhardness were assessed. SEM examined random samples. Statistical analysis used repeated measures ANOVA, and post hoc tests (p Results: The gingiva-coloured composites displayed noteworthy time-associated microhardness changes (p 0.05). Despite variable pH levels in beverages, no substantial group interaction effects were observed (p > 0.05). Initial microhardness rankings shifted after a 14-day immersion. Conclusions: Gingiva-coloured composite exhibited the highest microhardness pre- and post-immersion, followed by Procryla30 and Imicryl groups. .展开更多
Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionar...Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionary biology,but remains poorly understood at the genus level.Here,we used Callicarpa,a typical representative of pantropical angiosperm,to analyse whether fruit colours are correlated with biogeographic distribution,dispersal events,and diversification rate.We estimated a time-calibrated phylogeny for Callicarpa and reconstructed ancestral fruit colour.Utilizing phylogenetic methods,we estimated the major dispersal events across the phylogenetic tree and the most likely fruit colours related to each dispersal event,and tested whether the dispersal frequencies and distances of the four fruit colours between major biogeographical areas were equal.We then tested whether fruit colours are correlated with latitude,elevation,and diversification rate.Biogeographical reconstructions showed that Callicarpa originated in the East Asia and Southeast Asia during the Eocene(-35.53 Ma) and diverse species diverged mainly in the Miocene and lasted into the Pleistocene.Large-scale dispersal events were significantly associated with violet-fruited lineages.Furthermore,different fruit colours were markedly correlated with different latitudes and elevations(e.g.,violet fruits were correlated with higher latitudes and elevations;red fruits and black fruits with lower latitudes;white fruits with higher elevations).Notably,violet fruits were statistically associated with highest diversification rates,driving fruit colour variation among different regions globally.Our results contribute to further understanding why fruit colour is so variable at the genus level of angiosperms in different areas around the world.展开更多
The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afr...The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(P.afer),Grey-breasted Spurfowl(P.rufopictus) and Swainson’s Spurfowl(P.swainsonii).The rest of the species include fully feathered throated spurfowls.Throat colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s seasons.Each throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental variation.Except for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg laying.Swainson’s Spurfowl peaks during egg laying.Yellow-necked Spurfowl has the largest bare throat.Bare-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat colour.No such displays occur in feather-throated spurfowl.Males with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated throats.Male Red-necked Spurfowls have significantly larger bare throats than females.The primary function of bare throats probably assists in thermoregulation,particularly in arid regions.The bare throat may have evolved a secondary role in mating.Yellow-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding season.Unobtrusive female throat colours(unsaturated) may discourage male interlopers and predation during egg laying.Saturation appears to be carotenoid-food based.The different colours among the bare-throated species may serve as prezygotic mechanisms that inhibit cross-breeding and explain why females also have coloured throats.展开更多
Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homo...Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-injective oriented colouring problem. A dichotomy theorem is proved in each case.展开更多
Mobile games are gaining in popularity among students, although the factors driving engagement remain poorly understood. This study, conducted among 378 students studying for a Bachelor’s degree in Computer and Digit...Mobile games are gaining in popularity among students, although the factors driving engagement remain poorly understood. This study, conducted among 378 students studying for a Bachelor’s degree in Computer and Digital Sciences at the Université Virtuelle de Côte d’Ivoire, explores the influence of game assets and colours on player engagement. Using an online questionnaire, the study identified students’ gaming preferences and their perception of colours. The results show that the key elements most favoured by students are graphics, sound design, the game system, narrative, interactivity and accessibility. What’s more, colour plays a decisive role in their preferences and commitment to educational mobile games.展开更多
An f-edge cover-colouring of a graph G = (V, E) is an assignment of colours to the edges of G such that every colour appears at each vertex v ∈ V at least f(v) times. The maximum number of colours needed to f-edge co...An f-edge cover-colouring of a graph G = (V, E) is an assignment of colours to the edges of G such that every colour appears at each vertex v ∈ V at least f(v) times. The maximum number of colours needed to f-edge cover colour G is called the f-edge cover chromatic index of G, denoted by Xfc(G). This paper gives that min[d(v)-1/f(v)]≤xfc(G)≤展开更多
This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity a...This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity are calculated by the linear approximation. The effects caused by noise self-correlation time τ1, τ2 and cross-correlated time τ3 for stochastic resonance are analysed in two ways: τ1, τ2 and τ3 are taken to be the independent variables and the parameters respectively. The effects of the gain coefficient F and loss coefficient K on the stochastic resonance are also discussed. It is found that besides the presence of the standard form and the broad sense of stochastic resonance, the number of extrema in the curve of R versus K is reduced with the increase of the gain coefficient Г.展开更多
<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that trea...<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that treats dyed cotton fabric under dry condition so as to avoid chemical pollutants. This study means to explore colour reflectance of decolourized sulfur dyed cotton texture using ozone plasma treatment. Sulfur dyed cotton textures with various colour depths (0.5%, 1.5%, 2.5%) were set up to be treated different plasma parameters, including ozone air concentrations (10%, 30%, 50%, 70%), water contents in terms of weight percentage (35%, 45%) of fabric and ozone air plasma treatment periods (10 mins, 20 mins, 30 mins). The colour fading result is assessed by the colour reflectance in percentage (R%) utilizing spectrophotometer under CIE standard illuminant D65. The valid colour fading based on high percentage of reflectance was demonstrated from plasma treatment under higher ozone air concentration (50% and 70% ozone in air) and longer time length of plasma treatment (20 mins and 30 mins). The level of water content contained in the cotton fabrics is appeared to have noteworthy relationship with the degree of decolourization. </div>展开更多
This short paper is about art and science and the human struggle to figure out the world we live in. It is also about the imagination and human progress, rationality and subjectivity, as well as the development of dev...This short paper is about art and science and the human struggle to figure out the world we live in. It is also about the imagination and human progress, rationality and subjectivity, as well as the development of devices to ascertain out accurate knowledge--and yet the imagination and forms of thought are themselves devices that are integral to mechanical inventions. At the core of the subject under discussion, the aesthetic can be found reasons for the existence of other phenomena, the rational and the sensitive, epistemology and phenomenology, fulfilling human pleasure and necessity, and moving forward a humanized cosmos. Somewhere seems to rise and grow afresh a precise image of what we actually are and it can be revealed simply by being in the world and experiencing it on the basis of the mind-body-worM or by extending human senses through technology.展开更多
In co-colouration systems of rare earth(Ⅲ) with a metal(Ⅱ), induced colouration and decolouration ef- fects between different rare earths have been discovered. A sensitive co-colouration system of 《Lead(Ⅱ)-Rare Ea...In co-colouration systems of rare earth(Ⅲ) with a metal(Ⅱ), induced colouration and decolouration ef- fects between different rare earths have been discovered. A sensitive co-colouration system of 《Lead(Ⅱ)-Rare Earth(Ⅲ)-Alizarin Violet-Sensitizer》 was chosen as a typical one to study; and neodymium, gadolinium and yttrium were used to represent light, middle and heavy rare earths respectively. Semiquantitative relationships for the induced effects between yttrium and neodymium as well as between gadolinium and neodymium have been determined and discussed. In the presence of a sensitizer, these metal ions cannot always be coloured by alizarin violet when each of them is present alone, but a very sensitive co-colouration or co-decolouration may occur during their coexistence under certain conditions. If these metals exist as foreign ions in the photometric determination of another metal, serious unperceivable interference will possibly occur. Moreover, the condi- tions leading to induced co-colouration and co-decolouration are very complicated, so that close attention must be paid to this area in the photometric determination of certain metals.展开更多
An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS<...An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS</strong> is proposed. Base on <strong>Pauli Exclusion Principle</strong>, every quark is assigned to different flavour marks in STS. Every flavour quark possesses <em>its own colour spectral line array</em> specially appointed. The collection of colour spectral line arrays of the six flavour quarks constructs together the <strong>CSDF</strong>, Colour Spectrum Diagram of Flavour, further baryons and mesons could be constructed from <strong>CSDF</strong>. STS, Spin Topological Space is a math frame with infinite dimensional matrix representation for spin angular momentum. Flavours is an isospin angular momentum coupling phenomena of the three-colour-quarks.展开更多
The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on ra...The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD\5h -1\5A -1\5m -2 and energy consumption 20.61 kWh\5kg -1 of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD\5h -1\5A -1\5m -2 to 0.144 kWh\5kg -1 of COD while decrease the energy consumption from 20.61 kWh\5kg -1 of COD to 12.86 kWh\5kg -1 of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.展开更多
The effect of heat treatment on the surface colour and hygro- scopic properties of pine wood were investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal treatment at 20...The effect of heat treatment on the surface colour and hygro- scopic properties of pine wood were investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal treatment at 200℃, for 4, 6, and 8 h. The change of equilibrium moisture content and density values of the specimens in order to facilitate the understand- ing of the treated material behavior. The colour parameters L* a* and b*, used to depict the total colour change (dE) of wood surface, were shown to change proportionally to the treatment intensity. Moreover, swelling in the tangential and radial directions and absorption of the specimens ap- peared to be enhanced in great extent by the thermal treatment process. The mean value of swelling percentage in the tangential direction de- creased 10.26%, 17.22%, and 19.60% for specimens treated for 4, 6, and 8 h, respectively, referring to the final measurement after 72 h of immer- sion. In radial direction, mean value of swelling percentage decreased 19.56%, 32.75%, and 34.65% for treated for 4, 6 and 8 h, respectively, after 72 h immersion, which attests the decrease in swelling and im- provement in the hygroscopic behavior of Scots pine wood.展开更多
The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacture...The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes (△E*) were calculated on the basis of the Commission Internationale de I'Eclairage L*a*b* colour system (CIE L*a*b*), and the results were then converted into National Bureau of Standards (NBS) units. Fourier transformation infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher AE* values (ranging from 0.30 to 27.81) than those of the Angelalign and Smartee aligners (AE* values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P〈O.05). IFT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.展开更多
This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase-B (LDH-B) on the colour stability of mutton. From 60 sheep (Bayannur mutton sheep...This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase-B (LDH-B) on the colour stability of mutton. From 60 sheep (Bayannur mutton sheep), 15 Iongissimus dorsi (LD) muscles were selected on the basis of colour stability (R630/580 and a* value) during the storage and classified into three groups (5 for each group) as high colour stability (HCS), intermediate colour stability (ICS) and low colour stability (LCS). The activities of GAPDH and LDH-B, muscle colour attributes, nicotinamide adenine dinucleuotide (NADH) concen- tration and lactate concentration were measured. The samples in HCS had higher activities of GAPDH and LDH-B than the samples in the LCS, and the samples in the HCS group also possessed higher NADH and lower lactate concentration. The higher activity of dehydrogenase enzyme may result in higher NADH concentrations and colour stability in muscle tissue. The results suggest that the activity of GAPDH and LDH-B may also play a role in maintaining colour stability.展开更多
基金funded by the West Light Foundation of The Chinese Academy of Sciencesnational youth talent support programYunnan youth talents plan(YNWR-QNBJ-2018-183 to Y.N.)。
文摘Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.
文摘Purpose: The study investigated the impact of dietary habits, specifically soda, milk kefir, water kefir, almond milk, and distilled water (control) consumption, on the microhardness of gingiva-coloured composite and acrylic denture bases. Methods: Materials included gingiva-coloured composite (Fusion Universal G1), acrylic (Imicryl), and subdivided Procryla group. Subgroups comprised 15 and 30-minute heat polymerized (Pro15, Pro30), and 1 wt% (Pro1Z) and 3 wt% (Pro3Z) zirconium added groups. Immersed in beverages for 1, 7, and 14 days, pH and microhardness were assessed. SEM examined random samples. Statistical analysis used repeated measures ANOVA, and post hoc tests (p Results: The gingiva-coloured composites displayed noteworthy time-associated microhardness changes (p 0.05). Despite variable pH levels in beverages, no substantial group interaction effects were observed (p > 0.05). Initial microhardness rankings shifted after a 14-day immersion. Conclusions: Gingiva-coloured composite exhibited the highest microhardness pre- and post-immersion, followed by Procryla30 and Imicryl groups. .
基金funded by National Natural Science Foundation of China under Grant [31760045 and 31970220]Natural Science Foundation of Guangxi Province under Grant[2018GXNSFAA281132]。
文摘Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionary biology,but remains poorly understood at the genus level.Here,we used Callicarpa,a typical representative of pantropical angiosperm,to analyse whether fruit colours are correlated with biogeographic distribution,dispersal events,and diversification rate.We estimated a time-calibrated phylogeny for Callicarpa and reconstructed ancestral fruit colour.Utilizing phylogenetic methods,we estimated the major dispersal events across the phylogenetic tree and the most likely fruit colours related to each dispersal event,and tested whether the dispersal frequencies and distances of the four fruit colours between major biogeographical areas were equal.We then tested whether fruit colours are correlated with latitude,elevation,and diversification rate.Biogeographical reconstructions showed that Callicarpa originated in the East Asia and Southeast Asia during the Eocene(-35.53 Ma) and diverse species diverged mainly in the Miocene and lasted into the Pleistocene.Large-scale dispersal events were significantly associated with violet-fruited lineages.Furthermore,different fruit colours were markedly correlated with different latitudes and elevations(e.g.,violet fruits were correlated with higher latitudes and elevations;red fruits and black fruits with lower latitudes;white fruits with higher elevations).Notably,violet fruits were statistically associated with highest diversification rates,driving fruit colour variation among different regions globally.Our results contribute to further understanding why fruit colour is so variable at the genus level of angiosperms in different areas around the world.
文摘The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(P.afer),Grey-breasted Spurfowl(P.rufopictus) and Swainson’s Spurfowl(P.swainsonii).The rest of the species include fully feathered throated spurfowls.Throat colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s seasons.Each throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental variation.Except for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg laying.Swainson’s Spurfowl peaks during egg laying.Yellow-necked Spurfowl has the largest bare throat.Bare-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat colour.No such displays occur in feather-throated spurfowl.Males with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated throats.Male Red-necked Spurfowls have significantly larger bare throats than females.The primary function of bare throats probably assists in thermoregulation,particularly in arid regions.The bare throat may have evolved a secondary role in mating.Yellow-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding season.Unobtrusive female throat colours(unsaturated) may discourage male interlopers and predation during egg laying.Saturation appears to be carotenoid-food based.The different colours among the bare-throated species may serve as prezygotic mechanisms that inhibit cross-breeding and explain why females also have coloured throats.
文摘Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-injective oriented colouring problem. A dichotomy theorem is proved in each case.
文摘Mobile games are gaining in popularity among students, although the factors driving engagement remain poorly understood. This study, conducted among 378 students studying for a Bachelor’s degree in Computer and Digital Sciences at the Université Virtuelle de Côte d’Ivoire, explores the influence of game assets and colours on player engagement. Using an online questionnaire, the study identified students’ gaming preferences and their perception of colours. The results show that the key elements most favoured by students are graphics, sound design, the game system, narrative, interactivity and accessibility. What’s more, colour plays a decisive role in their preferences and commitment to educational mobile games.
文摘An f-edge cover-colouring of a graph G = (V, E) is an assignment of colours to the edges of G such that every colour appears at each vertex v ∈ V at least f(v) times. The maximum number of colours needed to f-edge cover colour G is called the f-edge cover chromatic index of G, denoted by Xfc(G). This paper gives that min[d(v)-1/f(v)]≤xfc(G)≤
文摘This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity are calculated by the linear approximation. The effects caused by noise self-correlation time τ1, τ2 and cross-correlated time τ3 for stochastic resonance are analysed in two ways: τ1, τ2 and τ3 are taken to be the independent variables and the parameters respectively. The effects of the gain coefficient F and loss coefficient K on the stochastic resonance are also discussed. It is found that besides the presence of the standard form and the broad sense of stochastic resonance, the number of extrema in the curve of R versus K is reduced with the increase of the gain coefficient Г.
文摘<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that treats dyed cotton fabric under dry condition so as to avoid chemical pollutants. This study means to explore colour reflectance of decolourized sulfur dyed cotton texture using ozone plasma treatment. Sulfur dyed cotton textures with various colour depths (0.5%, 1.5%, 2.5%) were set up to be treated different plasma parameters, including ozone air concentrations (10%, 30%, 50%, 70%), water contents in terms of weight percentage (35%, 45%) of fabric and ozone air plasma treatment periods (10 mins, 20 mins, 30 mins). The colour fading result is assessed by the colour reflectance in percentage (R%) utilizing spectrophotometer under CIE standard illuminant D65. The valid colour fading based on high percentage of reflectance was demonstrated from plasma treatment under higher ozone air concentration (50% and 70% ozone in air) and longer time length of plasma treatment (20 mins and 30 mins). The level of water content contained in the cotton fabrics is appeared to have noteworthy relationship with the degree of decolourization. </div>
文摘This short paper is about art and science and the human struggle to figure out the world we live in. It is also about the imagination and human progress, rationality and subjectivity, as well as the development of devices to ascertain out accurate knowledge--and yet the imagination and forms of thought are themselves devices that are integral to mechanical inventions. At the core of the subject under discussion, the aesthetic can be found reasons for the existence of other phenomena, the rational and the sensitive, epistemology and phenomenology, fulfilling human pleasure and necessity, and moving forward a humanized cosmos. Somewhere seems to rise and grow afresh a precise image of what we actually are and it can be revealed simply by being in the world and experiencing it on the basis of the mind-body-worM or by extending human senses through technology.
文摘In co-colouration systems of rare earth(Ⅲ) with a metal(Ⅱ), induced colouration and decolouration ef- fects between different rare earths have been discovered. A sensitive co-colouration system of 《Lead(Ⅱ)-Rare Earth(Ⅲ)-Alizarin Violet-Sensitizer》 was chosen as a typical one to study; and neodymium, gadolinium and yttrium were used to represent light, middle and heavy rare earths respectively. Semiquantitative relationships for the induced effects between yttrium and neodymium as well as between gadolinium and neodymium have been determined and discussed. In the presence of a sensitizer, these metal ions cannot always be coloured by alizarin violet when each of them is present alone, but a very sensitive co-colouration or co-decolouration may occur during their coexistence under certain conditions. If these metals exist as foreign ions in the photometric determination of another metal, serious unperceivable interference will possibly occur. Moreover, the condi- tions leading to induced co-colouration and co-decolouration are very complicated, so that close attention must be paid to this area in the photometric determination of certain metals.
文摘An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS</strong> is proposed. Base on <strong>Pauli Exclusion Principle</strong>, every quark is assigned to different flavour marks in STS. Every flavour quark possesses <em>its own colour spectral line array</em> specially appointed. The collection of colour spectral line arrays of the six flavour quarks constructs together the <strong>CSDF</strong>, Colour Spectrum Diagram of Flavour, further baryons and mesons could be constructed from <strong>CSDF</strong>. STS, Spin Topological Space is a math frame with infinite dimensional matrix representation for spin angular momentum. Flavours is an isospin angular momentum coupling phenomena of the three-colour-quarks.
文摘The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD\5h -1\5A -1\5m -2 and energy consumption 20.61 kWh\5kg -1 of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD\5h -1\5A -1\5m -2 to 0.144 kWh\5kg -1 of COD while decrease the energy consumption from 20.61 kWh\5kg -1 of COD to 12.86 kWh\5kg -1 of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.
文摘The effect of heat treatment on the surface colour and hygro- scopic properties of pine wood were investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal treatment at 200℃, for 4, 6, and 8 h. The change of equilibrium moisture content and density values of the specimens in order to facilitate the understand- ing of the treated material behavior. The colour parameters L* a* and b*, used to depict the total colour change (dE) of wood surface, were shown to change proportionally to the treatment intensity. Moreover, swelling in the tangential and radial directions and absorption of the specimens ap- peared to be enhanced in great extent by the thermal treatment process. The mean value of swelling percentage in the tangential direction de- creased 10.26%, 17.22%, and 19.60% for specimens treated for 4, 6, and 8 h, respectively, referring to the final measurement after 72 h of immer- sion. In radial direction, mean value of swelling percentage decreased 19.56%, 32.75%, and 34.65% for treated for 4, 6 and 8 h, respectively, after 72 h immersion, which attests the decrease in swelling and im- provement in the hygroscopic behavior of Scots pine wood.
基金funded by the Orthodontic National Key Clinical Specialty Construction Program of Chinathe West China Hospital of Stomatology Sichuan Universitysupported by grants from the National Natural Science Foundation of China (Grant No. 31470904 and 81470722)
文摘The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes (△E*) were calculated on the basis of the Commission Internationale de I'Eclairage L*a*b* colour system (CIE L*a*b*), and the results were then converted into National Bureau of Standards (NBS) units. Fourier transformation infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher AE* values (ranging from 0.30 to 27.81) than those of the Angelalign and Smartee aligners (AE* values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P〈O.05). IFT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.
基金financial support from the National Agricultural Science and Technology Innovation Program,Chinathe Special Fund for Agro-scientific Research in the Public Interest in China(201303083)the earmarked fund for China Agriculture Research System(CARS-39)
文摘This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase-B (LDH-B) on the colour stability of mutton. From 60 sheep (Bayannur mutton sheep), 15 Iongissimus dorsi (LD) muscles were selected on the basis of colour stability (R630/580 and a* value) during the storage and classified into three groups (5 for each group) as high colour stability (HCS), intermediate colour stability (ICS) and low colour stability (LCS). The activities of GAPDH and LDH-B, muscle colour attributes, nicotinamide adenine dinucleuotide (NADH) concen- tration and lactate concentration were measured. The samples in HCS had higher activities of GAPDH and LDH-B than the samples in the LCS, and the samples in the HCS group also possessed higher NADH and lower lactate concentration. The higher activity of dehydrogenase enzyme may result in higher NADH concentrations and colour stability in muscle tissue. The results suggest that the activity of GAPDH and LDH-B may also play a role in maintaining colour stability.