Assessing Gray Scale Grades for Color Change of Dyed Fabrics via Image Processing Technology

Gray scale grades for color change of dyed fabrics are assessed via image processing technology.Digital images of groups of specimens are obtained,cropped,and saved as JPEG format.Relationships between gray scale grades for color change and the corresponding color differences calculated via image processing technology are investigated,compared with those obtained from high accurate computer color matching system.Results show that the new method is acceptable with an accuracy of 92.0% when the grading errors are of not more than one grade.

Pressure-induced color change arising from transformation between intra-and inter-band transitions in LuH_(2±x)N_(y)

The pressure-induced color change in the nitrogen-doped lutetium hydride has triggered extensive discussions about the underlying physics and potential applications.Here,we study the optical response of LuH_(2±x)N_(y)in a broad frequency range at ambient pressure and its evolution with pressure in the visible spectral range.The broad-band optical spectra at ambient pressure reveal a Drude component associated with intra-band electronic transitions and two Lorentz components(L1 and L2)arising from inter-band electronic transitions.The application of pressure causes a spectral weight transfer from L1 to the Drude component,leading to a blue shift of the plasma edge in the reflectivity spectrum alongside a reduction of the high-frequency reflectivity.Our results suggest that the pressure-induced color change in LuH_(2±x)N_(y)is closely related to the transformation between intra-and inter-band electronic transitions,providing new insights into the mechanism of the pressure-induced color change in LuH_(2±x)N_(y).

Pressure induced color change and evolution of metallic behavior in nitrogen-doped lutetium hydride

By applying pressures up to 42 GPa on the nitrogen-doped lutetium hydride(LuH2_(±x)N_(y)),we have found a gradual change of color from dark-blue to pink-violet in the pressure region of about 12 to 21 GPa.The temperature dependence of resistivity under pressures up to 50.5 GPa shows progressively optimized metallic behavior with pressure.Interestingly,in the pressure region for the color change,a clear decrease of resistivity is observed with the increase of pressure,which is accompanied by a clear increase of the residual resistivity ratio(RRR).Fitting to the low temperature resistivity gives exponents of about 2,suggesting a Fermi-liquid behavior in the low temperature region.The general behavior in a wide temperature region suggests that the electron-phonon scattering is still the dominant one.The magnetoresistance up to 9 T in the state under a pressure of 50.5 GPa shows an almost negligible effect,which suggests that the electric conduction in the pink-violet state is dominated by a single band.It is highly desired to have theoretical efforts in understanding the evolution of color and resistivity in this interesting system.

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus

The autotetraploid Carassius auratus(4nRR,4n=200,RRRR)is derived from whole-genome duplication of Carassius auratus red var.(RCC,2n=100,RR).In the current study,we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin(red in RCC,brownish-yellow in4nRR).To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR,we performed transcriptome profiling and molecular functional verification in RCC and 4nRR.Results revealed that scarb1,associated with carotenoid metabolism,underwent significant down-regulation in 4nRR.Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration.Subsequently,we identified four divergent scarb1 homeologs in 4nRR:two original scarb1 homeologs from RCC and two duplicated ones.Notably,three of these homeologs possessed two highly conserved alleles,exhibiting biased and allelespecific expression in the skin.Remarkably,after precise editing of both the original and duplicated scarb1homeologs and/or alleles,4nRR individuals,whether singly or multiply mutated,displayed a transition from brownishyellow skin to a cyan-gray phenotype.Concurrently,the proportional areas of the cyan-gray regions displayed a gene-dose correlation.These findings illustrate the subfunctionalization of duplicated scarb1,with all scarb1genes synergistically and equally contributing to the pigmentation of 4nRR.This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploidfish,substantiallyenrichingour understanding of coloration formation and change within this group of organisms.

Biochemical regulation of pigment motility in vertebrate chromatophores： a review of physiological color change mechanisms

The fundamental unit of rapid, physiological color change in vertebrates is the dermal chromato- phore unit. This unit, comprised of cellular associations between different chromatophore types, is relatively conserved across the fish, amphibian, and reptilian species capable of physiological color change and numerous attempts have been made to understand the nature of the four major chro- matophore types （melanophores, erythrophores, xanthophores, and iridophores） and their bio- chemical regulation. In this review, we attempt to describe the current state of knowledge regard- ing what classifies a pigment cell as a dynamic chromatophore, the unique characteristics of each chromatophore type, and how different hormones, neurotransmitters, or other signals direct pig- ment reorganization in a variety of vertebrate taxa.

Color change in a marine isopod is adaptive in reducing predation

Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].

Integrated sensing from the synergetic color change of the center/brush of cholesteric liquid crystal particles

Cholesteric liquid crystal(CLC)particles can adaptively respond to constant changes in external stimuli and thus are widely used in solvent-sensing,pattern fabrication,and anti-counterfeiting.Previous studies discussed the color change at the center of the particles for various applications.However,few studies analyzed the color change of the brush structure of particles in response to various applications because of the complicated birefringence effect.In this paper,we present a novel integrated sensing system based on the synergetic color change from the center and the brush structure of CLC particles.This system provides abundant and additional sensing information relative to the traditional system.CLC particles are prepared by mixing reactive mesogens,a reactive chiral dopant,a non-reactive LC molecule,and a photoinitiator by using a microfluidic device and subsequent photopolymerization.The CLC particles exhibit gorgeous color at the center and brush structure upon various solvent stimuli because of the Bragg reflection and the birefringence effect,which is explained by the possible color-changing mechanism introduced in this paper.For proof-of-concept applications,such color-changing polymer particles are demonstrated in multi-solvent-sensing detection and pattern display.This study provides new insights into the development of stimuli-responsive advanced functional materials with tailorable nanostructures toward technological applications ranging from sensing to display.

Hormonal control of seasonal color change in female spiny-footed lizards:an observational and experimental approach

Breeding coloration of females often signals aspects of their reproductive status,suggesting a link between color and sex steroid hormones.In this study,we examined the relationships between 2 sex steroid hormones(progesterone and p-estradiol)and reproductive coloration in female spinyfooted lizards Acanthodactylus erythrurus.We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle,p-estradiol was negatively related to brightness and positively related to red saturation,whereas progesterone was not significantly related to coloration.After identifying key relationships,plasma hormone concentrations were manipulated by creating 3 experimental female groups(p-estradiol-treated,progesterone-treated,and control),and the effects on coloration were monitored,p-estradiol-treated females,in which there was a rise in both p-estradiol and progesterone levels,lost their red coloration earlier than females in the other 2 experimental groups,whereas progesterone treatment had no significant effect on female coloration.Our results suggest that high levels of either p-estradiol alone or(3-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards,and that progesterone alone does not affect coloration.We hypothesize that changes in female breeding color might be regulated by(3-estradiol in species in which conspicuous coloration is displayed before ovulation,and by progesterone in species in which this color is displayed during gravidity.

Change Color Effect and Spectral Properties of Gold Nanoparticle-cationic Surfactants System

The change color effect of gold nanoparticle solutions was studied by means of resonance scattering and absorption spectrometry and scan electron microscopy. The red Au nanoparticles with a size of 10 nm exhibit a resonance absorption peak and a resonance scattering peak all at 525 nm. After some inorganic electrolyte was added to a red Au nanoparticles solution, the color of the solution became blue and the absorbance at (600_700) nm was significantly increased. The ratio of the concentration of monovalent cations, at which the resonance scattering of the system at 525 nm is maximal to that of divalent cations, is in the range of 100∶1_100∶1.8. It is in good agreement with the Schulze-Hardy rule of the coagulation value of electrolyte. After adding some cationic surfactants to the above solution, the color of the solution is in deep blue, with two resonance absorption peaks at 550 and 680 nm, and a greatly enhanced resonance scattering peak at 525 nm. The experiments demonstrate that the stronger the hydrophobicity of the cationic surfactant is, the stronger the change color effect of the Au nanoparticle solution promoted by cationic surfactant is. The change color effect of Au nanoparticle solution is resulted from the increased diameter of Au nanoparticles, and the changes of resonance absorption peak and resonance scattering.

Gamma induced changes in Makrofol/CdSe nanocomposite films

We applied an ex-situ casting procedure to prepare a nanocomposite(NCP)from Makrofol polycarbonate(PC)and CdSe nanoparticles.The CdSe nanoparticles were prepared by a thermolysis procedure in the presence of N_(2) gas flow.Rietveld refinement of x-ray data illustrated that the CdSe adopts a cubic zinc blend structure of 6.057 A lattice parameter and 2 nm typical grain size.Samples from the prepared NCP were exposed to γ dosages(20 kGy-250 kGy).The modifications induced in the NCP films owing to γ dosages have been studied.Theγirradiation(50 kGy-250 kGy)causes crosslinks that reduce the optical bandgap from 4.15 eV to 3.81 eV,associated with an increase in dielectric parameters and refractive index.This is attributed to an increase in the mass fraction of the disordered regions as specified by x-ray diffraction.The PC-CdSe NCP was found to have a reaction to color modification which makes it suitable for saleable reproduction on a printing press.

Variation in phenolic composition and color features of red wine during vinification

The compositions and contents of phenolic components during the three periods(alcoholic fermentation,malolactic fermentation and aging process)of wine making by Cabernet Sauvignon were analyzed by high performance liquid chromatography.The color parameters of the wine were also determined by CIELab method.Correlation analysis and principal component analysis were adopted to analyze the correlation between phenolic content and color parameters.In fermentation and aging periods,anthocyanins and other phenolic components in wine increased at first,and before the end of malolactic fermentation,the contents reached the highest,and later experienced a downward trend,then contents change showed a stable trend in the later stage of storage.During the whole wine-making,anthocyanins had significant correlation with CIELab parameter a*and anthocyanin malvidin-3-O-glucoside was mainly observed to present a large impact on a*in aging period,causing the red color change of wine.Other phenolic components affected the CIELab parameters a*,b*and L*differently.Statistical analysis about the color parameters and 15 phenolic components revealed correlations between the color properties and detectable phenolic contents.

Effect of Aluminum Oxide on the Alteration Perceived Color ofDark Dental Substrates

The objective of the present research was to determine the degree of masking which occurs when 0.2 mm densely sintered aluminum oxide is placed over substrates of various colors. 20 lighter and 20 darker substrates were made from a mixture of dental amalgam and resin in an aluminum mold. The thin (0.2 mm) disks of densely sintered aluminum oxide were placed on the various substrates. The color changes after masking by these disks were recorded using a Minolta Chroma Meter Ⅱ. The results showed that the color (L *, a *, b *) changes after placing the disks over the substrates were obvious and lead to statistical significant differences (P<0.000 1) in ΔE, ΔL *, Δa *, Δb *. The masking ability was more pronounced with the aluminum oxide over the dark substrates than the light substrates.

Development,Characterization and Application of a Three-Layer Intelligent pH-Sensing Indicator Based on Bromocresol Green(BCG)for Monitoring Fish Freshness

As a novel food quality monitoring technology,intelligent freshness indicator has received wide attention in recent years.However,its poor safety and stability are the main problems hindering its practical application.Hence a new pH-sensing indicator based on bromocresol green(BCG)was developed in this study for nondestructive and real-time monitoring the freshness of marine fishes.The indicator was designed with a three-layer structure,using the polytetrafluoroethylene(PTFE)membrane with high hydrophobicity and air permeability as the inner layer to isolate the moisture in the package,BCG-coated filter paper as the colorchanging layer to indicate the freshness of fish,and a transparent unidirectional permeable(TUP)membrane with moisture resistance as the out layer to isolate the moisture in the environment.This contributed to weaken the influence of humidity and prevent dye migration,so as to improve the accuracy and safety of the indicator.Therefore,a highly sensitive and distinguished color variation response to trimethylamine(TMA)standard solution with different concentrations was observed on the indicator.Additionally,the indicator showed a high color stability at different storage temperatures up to 14 days with total color differences(ΔE)less than 5.0.The indicator presented visible color variations from yellow to green then eventually to blue when applied to monitor the freshness of sea bass and salmon stored at 4℃,implying that fish was spoiled.Meanwhile,indicatorsΔE value was significantly positively correlated with total volatile basic nitrogen(TVB-N)and total viable count(TVC)in sea bass and salmon samples.Thus,the pH-sensing indicator can be applied as a cost-effective and promising intelligent indicator for monitoring fish freshness.

Changes in color and rheological behavior of pineapple concentrate through various evaporation methods

The objective of this study was to investigate the effect of various concentration methods namely microwave vacuum evaporation(MVE),microwave heating evaporation(MHE),and rotary vacuum evaporation(RVE)on the concentrate change,the kinetic of color degradation,and the rheological behavior of pineapple juice.The concentrated behavior of pineapple juice from the experimental data of concentration rate was fitted with three types of exponential models for evaluating a suitable prediction.The four-parameter exponential model was found to agreeably explain the concentrated change of pineapple juice during each concentration methods.The Kinetics of color change during concentration processes was evaluated.The color changing from three different evaporations was measured by lightness values(L*),redness values(a*)and yellowness(b*)values,total color difference(TCD)and brown pigment formation index(A420).The result indicated that the change in Hunter parameters,L*and b*,fitted well with the first-order kinetic model while a*,TCD,and Browning index followed the zero-order kinetic model.The observed apparent viscosities(μa)of pineapple concentrate at 55-85℃through the three different evaporation methods were also measured.In relation to temperature and shear rate,the viscosity decreased as these two parameters increased,for all concentrated pineapple juice.On comparing the values ofμa of pineapple concentrate from different concentration methods,pineapple concentrate from MHE has higher values than those from MVE and RVE.The Duncan test,applied to the experimental results,indicates no significant difference in theμa of pineapple juice concentrate by MVE and by RVE.

Bioinspired multichannel colorful encryption through kirigami activating grating

Optical encryption,exploiting degrees of freedom of light as parameters to encode and decode information,plays an indispensable role in our daily life.Responsive structural color materials can give real-time visible feedback to external stimuli and provide ideal candidates for optical encryption.However,the development of existing responsive structural color materials is hindered by poor repeatability and long feedback time.Meanwhile,there are only few strategies to exploit structural colors in multichannel information encryption.Herein,bioinspired by the structural color variation due to a change in angle arising from the movement of animal’s scales or feathers,we developed a general multichannel information encryption strategy using a two-dimensional deformable kirigami arranging orientations of the grating arrays by design.The kirigami grating sheet shows rapid,repeatable,and programmable color change.This strategy utilizes the topological space deformation to guide the change of optical property,which suggests new possibilities for spatial and spectral encryption as well as mechano-sensing and camouflage.

Research on Relationships between the Pigment of Dunhuang Mogao Grottoes Frescoes and Ecological Microorganism

Dunhuang Mogao Grottoes is one of the largest art treasures in the world.She has a large number of murals,sculptures,beautiful and vivid;There are precious Buddhist scriptures,documents,noble and elegant.Spanning more than 1,600 years,the Mogao Grottoes show the world the extensive and profound Chinese culture with a long history.But over time,the murals in the Mogao Grottoes have also changed a lot.Thousands of years of wind and rain erosion,changes in the surrounding environment,and the influence of various biological communities have caused serious color changes and fading of murals in Mogao Grottoes.To slow down the color change of Dunhuang frescoes,protection measures should be taken from the perspective of ecological microorganisms.At present,Cladosporium,Planococcus,Phoma,Chaetomium,and other strains have caused serious discoloration or discoloration of murals to a certain extent.This paper studies the main color of Dunhuang frescoes,red,and summarizes the discoloration factors and mechanism of red lead.On this level,one should try to keep the murals and control the indoor temperature.Humidity,people,and other factors slow the fading of the murals.But these are often insufficient to protect the integrity of the murals,so we have conducted a review of the literature to provide an updated overview of the available evidence on the subject.

Detection of NO_2 Based on 4-Carboxyl-4′-hydroxy Azobenzene and Its Cu(II) Complex

An organic ligand and its Cu（II） complex formulated as （C13HloN203）·5H2O （H2L·5H2O, 1） and Cu（HL）2（phen）·0.125H2O （2, H2L = 4-carboxyl-4′-hydroxy azobenzene, phen = 1,10-phenanthroline） have been synthesized and structurally characterized by single-crystal X-ray diffraction. In the two compounds, H2L and HL exhibit a trans-conformation. Complex 2 shows a mononuclear Cu（Ⅱ） structure with the hydroxyl group of HL uncoordinated. Complex 2 is assembled into a three-dimensional （3D） supramolecular architecture by hydrogen bonds and π-π stacking interactions. H2L and compound 2 can detect NO2 via reversible and irreversible color changes, respectively. The mechanism for the color changes is investigated.

Observation on Culture Characteristics of Mycoplasma bovis with Four Different Antigen Quantification Methods

[Objective] The paper was to explore the antigen harvest time of Mycoplasrna bovis and the antigen quantification alternative method. [Method] M. bovis 08M strain was inoculated in the Thiaueourt＇s medium containing 10% horse serum. Four growth curves were plotted by simultaneously measuring color change units （CCU）, colony forming units （CFU）, protein concentration and nucleic acid levels within 110 h. [ Result] The growth of M. bovis was divided into four phases： the longarithmie phase appeared after being cultured for 10 h; the stationary phase appeared at 30 h with the highest number of viable cells up to 1. 0× 108 CCU/mL and 7.7 × 107 CCU/mL, respectively; and the decline phase started at 75 h. The protein concentration afM. bov/s increased rapidly from 15 to 35 h, reached 72.06 μg/mL at 35 h, then maintained at 53.38 - 70.65 μg/mL. The nucleic acid levels of M. bov/s increased rapidly from 15 h, and the cycle threshold （Ct） values were maintained between 15, 32 and 17.84 after 25 h. [ Conclusion] There was a good correlation between the protein concentration and variable count of M. bov/s at the early stationary phase, which was the best time period to harvest antigen. The protein concentration determination could be an alternative method to quantify antigen content of M. bovis when preparing inactivated M. boviz vaccine. Key words Mycoplasma boyis; Antigen quantification; Color change units; Colony forming units; Protein concentration; Nucleic acid content

Study on Weathering Behavior of Jack Pine Heat-Treated under Different Conditions

It is of considerable importance to investigate the influence of weathering on the degradation processes of heat-treated wood. Kiln-dried （untreated）jack pine （Pinus banksiana） and jack pine heat-treated at three different temperatures （190 ℃, 200 ℃, and 210 ℃） were exposed to artificial weathering for different periods in order to understand the degradation processes due to weathering. Before and after exposure, their color and wettability by water were determined. Structural changes and chemical modifications at exposed surfaces were also investigated using SEM （scanning electron spectroscopy）, FTIR （Fourier transforms infrared spectroscopy）, and XPS （X-ray photoelectron spectroscopy）. The results revealed that the photo-degradation of lignin and the presence of extractives play important roles in color change and wetting behavior of heat-treated wood surfaces during weathering. The structural changes also influence the wettability. The effects of weathering for woods heat-treated under different conditions were similar, but different from those for untreated wood.

Refractive Index Change and Color Center Formation in LiYF_4 Crystal Induced by a Femtosecond Laser

The refractive index change and color centers formation in LiYF4 crystal at room temperature are induced by a femtosecond laser irradiation. A mechanism for refractive index change and color centers formation is proposed.