Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration per...Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration performance in humid(such as forest)and dry(desert)environments.Herein,we combined catalytic chemical vapor deposition(CCVD)technology and a hydrothermal synthesis method to develop a FeSiB@C@NiBr_(2) atomic-scale double-shell gradient structure with rich interfaces.These nanosheet arrays favor interface polarization,impedance matching,and dipole polarization of the material,thereby optimizing the microwave absorption performance.The optimal reflection loss(RL)value of FeSiB@C@NiBr_(2) reached-59.6 dB at 9.2 GHz,and the effective absorption bandwidth(EAB)reached 7.0 GHz at a thickness of 2.5 mm.Compared with pure FeSiB(RL_(min) of-13.5 dB),the RLmin value of the absorber designed by this method increased by~3 times.The color of NiBr_(2) in the outermost nanosheet arrays changes between yellow and green in the case of water molecule harvesting and loss,respectively.This novel FeSiB@C@NiBr_(2) composite structure material is expected to provide a promising platform for wave-absorbing and smart discoloring materials.展开更多
A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discolor...A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discoloration process and the corresponding main corrosion products can be summarized as follows:silver-white(Cu+Ni)→green(NiO)→reddishbrown(NiO+Cu_(2)O)→black(NiO+Cu_(2)O+CuO).Density functional theory was employed to explain the corrosion process of copper-nickel alloys and the detrimental effect of Cl^(−).The results indicate that adsorbates preferentially bind to nickel,leading to the preferential formation of NiO,which imparts a green appearance to the surface.Furthermore,the difficulty in forming nickel cation vacancies and the higher diffusion barrier for nickel inhibit the migration of species within the oxide layer.Notably,nickel also suppresses carrier migration within the oxide layer,reducing the charge transfer rate.In contrast,the promotion of corrosion by Cl^(−)is primarily attributed to the reduction in surface work function and the formation energy of cation vacancies.展开更多
The textile industry generates large volumes of waste throughout its production process.Most of this waste is colored,therefore,discoloration is an important step toward recycling and reusing this waste.This study foc...The textile industry generates large volumes of waste throughout its production process.Most of this waste is colored,therefore,discoloration is an important step toward recycling and reusing this waste.This study focused on the chemical reductive discoloration of textile waste composed of cotton dyed with reactive dye.The experimental design demonstrated the significant influence of the concentration of reducing agent and time of reaction on the degree of whiteness of the cotton fibers.The concentration of the alkaline agent was not significant in the process.The optimization of the reaction conditions lead to Berger degree of 50.5±3.5.The discolored cotton was chemically recycled through dissolution in ionic liquid 1-ethyl-3-methylimidazolium chloride and regeneration in film form in water.The microstructure of the regenerated cellulose films was evaluated by Scanning Electron Microscopy(SEM)indicating complete dissolution and uniform regeneration.The discoloration process reduced the polymerization degree and crystallinity index of the cotton fibers but retained the cellulose I structure.The dissolution and cellulose regeneration process results in transparent films with an amorphous structure.The thermal behavior,evaluated by thermogravimetric analysis,indicated that residues and regenerated film presented a main decomposition step.The maximum decomposition rate temperature of the regenerated films was approximately 40℃lower than the cotton fibers,which correlates well with the reduction in polymerization degree and amorphous structure.In general,the study demonstrated that textile cotton waste dyed with reactive dyes can be chemically discolored to form transparent and amorphous films,contributing to the development of sustainable strategies for the textile industry.展开更多
Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions ...Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anticounterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed.展开更多
A dielectric barrier discharge （DBD） reactor with a rod-plate electrode configuration was used for the oxidative decomposition of Congo red dye in an aqueous solution. Plasma was generated in the gas space above the...A dielectric barrier discharge （DBD） reactor with a rod-plate electrode configuration was used for the oxidative decomposition of Congo red dye in an aqueous solution. Plasma was generated in the gas space above the water interface under atmospheric pressure. Discharge characteristics were analyzed by voltage-current waveforms. Effects of applied voltage, initial conductivity, and initial concentration were also analyzed. Congo red discoloration increased with increased applied voltage and decreased conductivity. The initial conductivity significantly influenced the Congo red discoloration. Under the same conditions, the highest discoloration rate was obtained at 25 mg/L. The presence of ferrous ions in the solutions had a substantial positive effect on Fenton dye degradation and flocculation. At an applied voltage of 20 kV, about 100% of dye was degraded after 4 min of Fe^2＋/DBD treatment. Results showed that adding a certain dosage of hydrogen peroxide to the wastewater could enhance the discoloration rate. Possible pathways of Congo red discoloration by DBD plasma were proposed based on GC/MS, FTIR, and UV-vis spectroscopy analyses.展开更多
The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to...The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to the UV-ray irradiation were determined for 18 kinds of commercial dyes. The results are as follows： 1） the adsorptive properties of dyes to cellulose sheet differed greatly, but did not depend on the dye types such as acidic, basic and so on; 2） adsorptive properties of dyes to cellulosic sheet de- pended on the concentration of dye solution and were classified into 4 types： concentration-independent, increasing or decreasing with dye concentration, and having a maximum. This classification was irrelevant to the dye types; 3） the irradiation of UV-ray did not cause significant discoloration of dye solution itself, which suggested that wood components as well as dye molecules influence the discoloration of wood.展开更多
·AIM: To study the feasibility of using the discoloration to evaluate the biomechanical properties after treating with genipin.·METHODS: Porcine cadaver eyes were treated for30 min with 1.0%(by w/v) genipin....·AIM: To study the feasibility of using the discoloration to evaluate the biomechanical properties after treating with genipin.·METHODS: Porcine cadaver eyes were treated for30 min with 1.0%(by w/v) genipin. Untreated samples were used as controls. After treatment, scleral strips of4.0 ×10.0-mm2 were cut. The denaturation temperature(Td) measurement and stress-strain test were performed after taking photograph to analyze the color.·RESULTS: Within 24 h after treating with genipin, the sclera exhibited a bluish color which became deeper with time. And the denaturation temperature also was increased gradually. Compared with untreated groups, at1, 6, 12, 24 and 36 h after treatment, the ultimate stress were increased by 56%, 153%, 173%, 225% and 211%respectively. The Young’s modulus at 10% strain also increased by 170%, 246%, 264%, 389% and 288%respectively. There were strong correlation between the discoloration and the biomechanical properties(ΔE-Ultimate stress:R2=0.892, P =0.00; ΔE-Young’s modulus:R2=0.602, P =0.00).·CONCLUSION: Genipin could be used to strengthen collagen gradually in a relatively short time span. And the biomechanical properties could be reliably evaluated via simple visible discoloration.展开更多
Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five diff...Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five different drying methods, steam treated and exposed to weathering. Their colors were measured using a spectrophotometer and comparisons made both among species and drying methods. For Japanese and Korean pines, high temperature dried and steam-dried specimens showed distinct color differences compared with the controls. Steam treatment discolored the dried specimens of Japanese and Korean pines but did not discolor those of larch. After weathering for 144 days the specimens of Japanese pine showed slight color differences among drying methods.展开更多
The effects of thickness and types of gold plating on the resistance to hightemperature discoloration of gold plating on cavity surface of ceramic package were investigated. Itwas found that the thicker gold plating, ...The effects of thickness and types of gold plating on the resistance to hightemperature discoloration of gold plating on cavity surface of ceramic package were investigated. Itwas found that the thicker gold plating, the less discoloration degree for ceramic packages.Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide goldplating. The relationship between the gold plating thickness and the amount of diffused Ni to thegold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃ for 15 minwas also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Coplating systems, respectively, no discoloration was observed on the gold plating surface of cavity,and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Coto the gold plating is 0.04%.展开更多
Objective: The aim of this study was to investigate, in vitro, the color changes of the teeth, induced by endodontic sealers. Materials and Methods: Forty-five mature maxillary and mandibular anterior teeth, extracted...Objective: The aim of this study was to investigate, in vitro, the color changes of the teeth, induced by endodontic sealers. Materials and Methods: Forty-five mature maxillary and mandibular anterior teeth, extracted for periodontal reasons, were collected. After the chemo-mechanical instrumentation of the root canal, teeth were filled with four endodontic sealers (Endomethason, AH+, Canason and Apexit). Depending on canal sealers and the CEJ (Cement Enamel Junction), teeth were divided into 8 experimental groups (n = 5) and one control group/CG (n = 5). Teeth color changes (L*a*b*/CIE Commission Internationaled’ Eclaraige) were determinated by a spectrophotometer Vita Easyshade in 4 stages (Baseline, Week 0, 4 and 12). Results: Between the EOCEJ and CG for the parameter L*, there was a statistical significance (p 0.05). The L*a*b* results were: L* (83.6 ± 4.8 → 83.6 ± 4.9);a* (﹣2.68 ± 1.02 → ﹣1.12 ± 0.72) and b* (20.2 ± 4.5 → 24.4 ± 4.2). Conclusions: All endodontic sealers may cause teeth discoloration.展开更多
The effects of thickness and types of gold plating on the resistance to high temperature discoloration of gold plating on cavity surface of ceramic package were investigated. It was found that the thicker gold plating...The effects of thickness and types of gold plating on the resistance to high temperature discoloration of gold plating on cavity surface of ceramic package were investigated. It was found that the thicker gold plating, the less discoloration degree for ceramic packages. Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide gold plating. The relationship between the gold plating thickness and the amount of diffused Ni to the gold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃for 15 min was also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Co plating systems, respectively, no discoloration was observed on the gold plating surface of cavity, and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Co to the gold plating is 0.04%.展开更多
During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the envir...During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the environment. The use of ozone in wastewater treatment results of interest. In this work we propose to assess the discoloration rate of different synthetic wastewaters as a function of pH, dye concentration (methylene blue (MB)) and reaction time. A comparison of discoloration rate between conventional ozonation and catalytic ozonation salts of copper, zinc, silver and nickel was also performed. For the optimization of the ozonation process of colored solutions, it was used a central composite experimental design with five replicates of the center point resulting to evaluate the influence of the independent variables at different ranges of pH, [MB] and time. In the catalyst-assisted ozonation, [MB], pH and the reaction time were fixed to 100 mg/L, 5.5 and 15 min, respectively. The optimized experimental conditions to provide maximum discoloration were pH=3.3;[MB]=8.6 mg/L and time=74.3 min. Regarding the catalyst-assisted ozonation, it was found that CuSO4 catalyst gave better color reduction if compared with other catalysts assayed.展开更多
The radiative hypothesis has been revisited showing other characteristics, produced by the protons used as dyes in total disagree with the ones of the Body Image that appears on the Shroud of Turin. Our investigations...The radiative hypothesis has been revisited showing other characteristics, produced by the protons used as dyes in total disagree with the ones of the Body Image that appears on the Shroud of Turin. Our investigations highlight that for the protons to reach 3.7 cm in air, the distance that measures the range of discoloration effects, must be emitted with an energy of about 1.5 MeV using Wilson and Brobeck’s empirical formula and 1.35 MeV using Bethe’s. This last formula provides a result closer to reality. Bethe shows that the penetration depth is greater than that calculated empirically. Such a value of proton energy (1.35 MeV) makes it possible to satisfy the discoloration effects range for the Shroud but it is incompatible with a depth of penetration in linen that is only 200 nm. Moreover, using the same subatomic particles, we obtained on the colored linen a distribution of energy represented by regression but not linear. Thus, also the possible I(z) correlation, between color intensity and body-sheet distance, which should be due to the oxidizing action of protons, does not agree with that extracted from the Shroud of Turin.展开更多
Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has bee...Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has been well-documented in prior research,molecular investigations focusing on AP2/ERF remain notably lacking in Acer paxii.This research focuses on performing an extensive genome-wide investigation to identify and characterize the AP2/ERF gene family in Acer paxii.As a result,123 ApAP2/ERFs were obtained.Phylogenetic analyses categorized the ApAP2/ERF family members into 15 subfamilies.The evolutionary traits of the ApAP2/ERFs were investigated by analyzing their chromosomal locations,conserved proteinmotifs,and gene duplication events.Moreover,investigating gene promoters revealed their potential involvement in developmental regulation,physiological processes,and stress adaptationmechanisms.Measurements of anthocyanin content revealed a notable increase in red leaves during autumn.Utilizing transcriptome data,transcriptomic profiling revealed that the majority of AP2/ERF genes in Acer paxii displayed significant differential expression between red and green leaves during the color-changing period.Furthermore,through qRT-PCR analysis,it was found that the gene expression levels of ApERF006,ApERF014,ApERF048,ApERF097,and ApERF107 were significantly elevated in red leaves.This indicates their potential participation in leaf pigmentation processes.These findings offer significant insights into the biological significance of ApAP2/ERF transcription factors and lay the groundwork for subsequent investigations into their regulatorymechanisms underlying leaf pigmentation in Acer paxii.展开更多
As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fento...As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B (RhB), in an aqueous solution. Through a number of batch discoloration experiments under various conditions, it was found that the reactivity of the system increased by, respectively, increasing schorl dosage, temperature, hydrogen peroxide starting concentration and by decreasing the pH. Over 90% of discoloration ratio could be gained in less than 30 min, and nearly 70% of total organic carbon (TOC) could be removed in less than 200 min. And, the schorl catalyst could be repeatedly used at least ten times, still with high catalytic activity. Comparative studies indicated that the RhB discoloration ratios were much higher in presence of schorl and H2O2 than those in presence of schorl or H2O2 only, which suggested that the schorl-catalyzed Fenton-like reaction governed the RhB discoloration process. The content of Fe ion leaching in the solution was also measured using inductively coupling plasma-atomic emission spectra (ICP-AES). A mechanism proposed herein suggested that adsorption and Fenton-like reaction (heterogeneous and homogeneous) were responsible for the discoloration of RhB.展开更多
The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butt...The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.展开更多
The study illustrates differences between colors of poplar I-214 veneers dyed by reactive blue KN-R and 4 kinds of chemical reagents, and those of treated veneer exposed to UV-ray for 3 days. The results show there ar...The study illustrates differences between colors of poplar I-214 veneers dyed by reactive blue KN-R and 4 kinds of chemical reagents, and those of treated veneer exposed to UV-ray for 3 days. The results show there are some laws in poplar I-214 dyeing and UV-ray attenuation of each chemically treated veneer color. The chemical reaction carded out between cellulose or lignin on veneer surface and dye molecules when they met with. The capability of dyeing and discoloration of veneer is improved by control of dyeing technology, especially chemical treatments; being treated by acetylation and maleic anhydride protects dyed wood discoloration.展开更多
Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing ...Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing schorl dosage, temperature, initial H2O2 concentration, and by decreasing solution pH. When the raw schorl and the schorl samples sintered at 750°C, 850°C, 950°C and 1050°C were used as catalyst in Fenton-like system, the MO discoloration ratios obtained were 82%, 31%, 30%, 31% and 7%, respectively. XRD results showed that samples sintered at 750°C, 850°C and 950°C had no change in structure and still held the crystal structure of schorl and quartz, but, the content of schorl crystal decreased. Whereas, schorl crystal completely disappeared in the sample sintered at 1050°C and two new crystal phases of hematite and spinel were formed, which resulted in disappearance of the spontaneous ‘electrostatic poles’. Hence, it was inferred that the electrostatic field of schorl crystal could enhance the MO discoloration by schorl-catalyzed Fenton-like reaction.展开更多
This paper reviews the mechanisms, types, compositions, affecting factors, prevention and remediable treatments of wood discoloration, and especially puts forward the biological control against wood stain and wood ind...This paper reviews the mechanisms, types, compositions, affecting factors, prevention and remediable treatments of wood discoloration, and especially puts forward the biological control against wood stain and wood induced coloration. The authors think the followings are important: 1) Developing the low poisonous ornon-toxic, high-efficient and multi-functional anti-stain chemicalsis still an important research direction to control wood discoloration. 2) It is still very necessary to remove wood stain and restore wood original color and commercial value. 3) The biological control has little environmental pollution and its cost is low. Researches on its theories and application should be strengthened. 4) Wood color can be induced and turned to be the needed through heat treatment or ultraviolet irradiation without coloring materials, i.e. induced coloration, is agood idea to modulatewood, bamboo or rattan cane color. It is becoming a new study field.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51972045 and 52202368)the Fundamental Research Funds for the Chinese Central Universities,China(No.ZYGX2019J025)Sichuan Science and Technology Program(No.2021YFG0373).
文摘Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration performance in humid(such as forest)and dry(desert)environments.Herein,we combined catalytic chemical vapor deposition(CCVD)technology and a hydrothermal synthesis method to develop a FeSiB@C@NiBr_(2) atomic-scale double-shell gradient structure with rich interfaces.These nanosheet arrays favor interface polarization,impedance matching,and dipole polarization of the material,thereby optimizing the microwave absorption performance.The optimal reflection loss(RL)value of FeSiB@C@NiBr_(2) reached-59.6 dB at 9.2 GHz,and the effective absorption bandwidth(EAB)reached 7.0 GHz at a thickness of 2.5 mm.Compared with pure FeSiB(RL_(min) of-13.5 dB),the RLmin value of the absorber designed by this method increased by~3 times.The color of NiBr_(2) in the outermost nanosheet arrays changes between yellow and green in the case of water molecule harvesting and loss,respectively.This novel FeSiB@C@NiBr_(2) composite structure material is expected to provide a promising platform for wave-absorbing and smart discoloring materials.
基金supported by the Key Program of the National Natural Science Foundation of China(Grant No.51131007)the National Key Research and Development Program of China(Grant No.2021YFC2803102).
文摘A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discoloration process and the corresponding main corrosion products can be summarized as follows:silver-white(Cu+Ni)→green(NiO)→reddishbrown(NiO+Cu_(2)O)→black(NiO+Cu_(2)O+CuO).Density functional theory was employed to explain the corrosion process of copper-nickel alloys and the detrimental effect of Cl^(−).The results indicate that adsorbates preferentially bind to nickel,leading to the preferential formation of NiO,which imparts a green appearance to the surface.Furthermore,the difficulty in forming nickel cation vacancies and the higher diffusion barrier for nickel inhibit the migration of species within the oxide layer.Notably,nickel also suppresses carrier migration within the oxide layer,reducing the charge transfer rate.In contrast,the promotion of corrosion by Cl^(−)is primarily attributed to the reduction in surface work function and the formation energy of cation vacancies.
基金supportad by Fundação de AmparoàPesquisa e Inovação do Estado de Santa Caturina(FAPESC)(Grant Number 2021TR000327)by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES)-Finance Code 001.
文摘The textile industry generates large volumes of waste throughout its production process.Most of this waste is colored,therefore,discoloration is an important step toward recycling and reusing this waste.This study focused on the chemical reductive discoloration of textile waste composed of cotton dyed with reactive dye.The experimental design demonstrated the significant influence of the concentration of reducing agent and time of reaction on the degree of whiteness of the cotton fibers.The concentration of the alkaline agent was not significant in the process.The optimization of the reaction conditions lead to Berger degree of 50.5±3.5.The discolored cotton was chemically recycled through dissolution in ionic liquid 1-ethyl-3-methylimidazolium chloride and regeneration in film form in water.The microstructure of the regenerated cellulose films was evaluated by Scanning Electron Microscopy(SEM)indicating complete dissolution and uniform regeneration.The discoloration process reduced the polymerization degree and crystallinity index of the cotton fibers but retained the cellulose I structure.The dissolution and cellulose regeneration process results in transparent films with an amorphous structure.The thermal behavior,evaluated by thermogravimetric analysis,indicated that residues and regenerated film presented a main decomposition step.The maximum decomposition rate temperature of the regenerated films was approximately 40℃lower than the cotton fibers,which correlates well with the reduction in polymerization degree and amorphous structure.In general,the study demonstrated that textile cotton waste dyed with reactive dyes can be chemically discolored to form transparent and amorphous films,contributing to the development of sustainable strategies for the textile industry.
基金the National Natural Science Foundation of China(Grant Nos.51372200 and 51772243)the Foundation of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP201753)+2 种基金Scientific Research Plan Projects of Shaanxi Education Department(Grant No.16JK1551)Technology Innovation Programme of Xi’an University of Technology(Grant No.2016CX030)China Postdoctoral Science Foundation(Grant No.2016M592824)
文摘Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anticounterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed.
基金supported by National Natural Science Foundation of China(No.51377075)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20131412,BK20150951)
文摘A dielectric barrier discharge （DBD） reactor with a rod-plate electrode configuration was used for the oxidative decomposition of Congo red dye in an aqueous solution. Plasma was generated in the gas space above the water interface under atmospheric pressure. Discharge characteristics were analyzed by voltage-current waveforms. Effects of applied voltage, initial conductivity, and initial concentration were also analyzed. Congo red discoloration increased with increased applied voltage and decreased conductivity. The initial conductivity significantly influenced the Congo red discoloration. Under the same conditions, the highest discoloration rate was obtained at 25 mg/L. The presence of ferrous ions in the solutions had a substantial positive effect on Fenton dye degradation and flocculation. At an applied voltage of 20 kV, about 100% of dye was degraded after 4 min of Fe^2＋/DBD treatment. Results showed that adding a certain dosage of hydrogen peroxide to the wastewater could enhance the discoloration rate. Possible pathways of Congo red discoloration by DBD plasma were proposed based on GC/MS, FTIR, and UV-vis spectroscopy analyses.
基金Supported by the Research Planning of Japan-China Cooperation Project (The Research Project on Timber from Man-made Forests in China: JICA Project)
文摘The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to the UV-ray irradiation were determined for 18 kinds of commercial dyes. The results are as follows： 1） the adsorptive properties of dyes to cellulose sheet differed greatly, but did not depend on the dye types such as acidic, basic and so on; 2） adsorptive properties of dyes to cellulosic sheet de- pended on the concentration of dye solution and were classified into 4 types： concentration-independent, increasing or decreasing with dye concentration, and having a maximum. This classification was irrelevant to the dye types; 3） the irradiation of UV-ray did not cause significant discoloration of dye solution itself, which suggested that wood components as well as dye molecules influence the discoloration of wood.
基金Supported by Science and Technology Projects of Guangdong Province,China(No.2007B031002001,No.2008B030301086)
文摘·AIM: To study the feasibility of using the discoloration to evaluate the biomechanical properties after treating with genipin.·METHODS: Porcine cadaver eyes were treated for30 min with 1.0%(by w/v) genipin. Untreated samples were used as controls. After treatment, scleral strips of4.0 ×10.0-mm2 were cut. The denaturation temperature(Td) measurement and stress-strain test were performed after taking photograph to analyze the color.·RESULTS: Within 24 h after treating with genipin, the sclera exhibited a bluish color which became deeper with time. And the denaturation temperature also was increased gradually. Compared with untreated groups, at1, 6, 12, 24 and 36 h after treatment, the ultimate stress were increased by 56%, 153%, 173%, 225% and 211%respectively. The Young’s modulus at 10% strain also increased by 170%, 246%, 264%, 389% and 288%respectively. There were strong correlation between the discoloration and the biomechanical properties(ΔE-Ultimate stress:R2=0.892, P =0.00; ΔE-Young’s modulus:R2=0.602, P =0.00).·CONCLUSION: Genipin could be used to strengthen collagen gradually in a relatively short time span. And the biomechanical properties could be reliably evaluated via simple visible discoloration.
文摘Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five different drying methods, steam treated and exposed to weathering. Their colors were measured using a spectrophotometer and comparisons made both among species and drying methods. For Japanese and Korean pines, high temperature dried and steam-dried specimens showed distinct color differences compared with the controls. Steam treatment discolored the dried specimens of Japanese and Korean pines but did not discolor those of larch. After weathering for 144 days the specimens of Japanese pine showed slight color differences among drying methods.
文摘The effects of thickness and types of gold plating on the resistance to hightemperature discoloration of gold plating on cavity surface of ceramic package were investigated. Itwas found that the thicker gold plating, the less discoloration degree for ceramic packages.Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide goldplating. The relationship between the gold plating thickness and the amount of diffused Ni to thegold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃ for 15 minwas also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Coplating systems, respectively, no discoloration was observed on the gold plating surface of cavity,and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Coto the gold plating is 0.04%.
文摘Objective: The aim of this study was to investigate, in vitro, the color changes of the teeth, induced by endodontic sealers. Materials and Methods: Forty-five mature maxillary and mandibular anterior teeth, extracted for periodontal reasons, were collected. After the chemo-mechanical instrumentation of the root canal, teeth were filled with four endodontic sealers (Endomethason, AH+, Canason and Apexit). Depending on canal sealers and the CEJ (Cement Enamel Junction), teeth were divided into 8 experimental groups (n = 5) and one control group/CG (n = 5). Teeth color changes (L*a*b*/CIE Commission Internationaled’ Eclaraige) were determinated by a spectrophotometer Vita Easyshade in 4 stages (Baseline, Week 0, 4 and 12). Results: Between the EOCEJ and CG for the parameter L*, there was a statistical significance (p 0.05). The L*a*b* results were: L* (83.6 ± 4.8 → 83.6 ± 4.9);a* (﹣2.68 ± 1.02 → ﹣1.12 ± 0.72) and b* (20.2 ± 4.5 → 24.4 ± 4.2). Conclusions: All endodontic sealers may cause teeth discoloration.
文摘The effects of thickness and types of gold plating on the resistance to high temperature discoloration of gold plating on cavity surface of ceramic package were investigated. It was found that the thicker gold plating, the less discoloration degree for ceramic packages. Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide gold plating. The relationship between the gold plating thickness and the amount of diffused Ni to the gold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃for 15 min was also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Co plating systems, respectively, no discoloration was observed on the gold plating surface of cavity, and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Co to the gold plating is 0.04%.
文摘During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the environment. The use of ozone in wastewater treatment results of interest. In this work we propose to assess the discoloration rate of different synthetic wastewaters as a function of pH, dye concentration (methylene blue (MB)) and reaction time. A comparison of discoloration rate between conventional ozonation and catalytic ozonation salts of copper, zinc, silver and nickel was also performed. For the optimization of the ozonation process of colored solutions, it was used a central composite experimental design with five replicates of the center point resulting to evaluate the influence of the independent variables at different ranges of pH, [MB] and time. In the catalyst-assisted ozonation, [MB], pH and the reaction time were fixed to 100 mg/L, 5.5 and 15 min, respectively. The optimized experimental conditions to provide maximum discoloration were pH=3.3;[MB]=8.6 mg/L and time=74.3 min. Regarding the catalyst-assisted ozonation, it was found that CuSO4 catalyst gave better color reduction if compared with other catalysts assayed.
文摘The radiative hypothesis has been revisited showing other characteristics, produced by the protons used as dyes in total disagree with the ones of the Body Image that appears on the Shroud of Turin. Our investigations highlight that for the protons to reach 3.7 cm in air, the distance that measures the range of discoloration effects, must be emitted with an energy of about 1.5 MeV using Wilson and Brobeck’s empirical formula and 1.35 MeV using Bethe’s. This last formula provides a result closer to reality. Bethe shows that the penetration depth is greater than that calculated empirically. Such a value of proton energy (1.35 MeV) makes it possible to satisfy the discoloration effects range for the Shroud but it is incompatible with a depth of penetration in linen that is only 200 nm. Moreover, using the same subatomic particles, we obtained on the colored linen a distribution of energy represented by regression but not linear. Thus, also the possible I(z) correlation, between color intensity and body-sheet distance, which should be due to the oxidizing action of protons, does not agree with that extracted from the Shroud of Turin.
基金supported by the National Natural Science Foundation of China[grant numbers 32271914 and 32301660]the Quality Engineering Project of Anhui Provincial Department of Education[grant number 2023zygzts007].
文摘Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has been well-documented in prior research,molecular investigations focusing on AP2/ERF remain notably lacking in Acer paxii.This research focuses on performing an extensive genome-wide investigation to identify and characterize the AP2/ERF gene family in Acer paxii.As a result,123 ApAP2/ERFs were obtained.Phylogenetic analyses categorized the ApAP2/ERF family members into 15 subfamilies.The evolutionary traits of the ApAP2/ERFs were investigated by analyzing their chromosomal locations,conserved proteinmotifs,and gene duplication events.Moreover,investigating gene promoters revealed their potential involvement in developmental regulation,physiological processes,and stress adaptationmechanisms.Measurements of anthocyanin content revealed a notable increase in red leaves during autumn.Utilizing transcriptome data,transcriptomic profiling revealed that the majority of AP2/ERF genes in Acer paxii displayed significant differential expression between red and green leaves during the color-changing period.Furthermore,through qRT-PCR analysis,it was found that the gene expression levels of ApERF006,ApERF014,ApERF048,ApERF097,and ApERF107 were significantly elevated in red leaves.This indicates their potential participation in leaf pigmentation processes.These findings offer significant insights into the biological significance of ApAP2/ERF transcription factors and lay the groundwork for subsequent investigations into their regulatorymechanisms underlying leaf pigmentation in Acer paxii.
基金Supported by Heilongjiang Science Fundation for Young Scholars (Grant No. QC07C02)Scientific Foundation of Heilongjiang Education Department, China (Grant No. 11531035)
文摘As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B (RhB), in an aqueous solution. Through a number of batch discoloration experiments under various conditions, it was found that the reactivity of the system increased by, respectively, increasing schorl dosage, temperature, hydrogen peroxide starting concentration and by decreasing the pH. Over 90% of discoloration ratio could be gained in less than 30 min, and nearly 70% of total organic carbon (TOC) could be removed in less than 200 min. And, the schorl catalyst could be repeatedly used at least ten times, still with high catalytic activity. Comparative studies indicated that the RhB discoloration ratios were much higher in presence of schorl and H2O2 than those in presence of schorl or H2O2 only, which suggested that the schorl-catalyzed Fenton-like reaction governed the RhB discoloration process. The content of Fe ion leaching in the solution was also measured using inductively coupling plasma-atomic emission spectra (ICP-AES). A mechanism proposed herein suggested that adsorption and Fenton-like reaction (heterogeneous and homogeneous) were responsible for the discoloration of RhB.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325501,51505183&51290292)China Postdoctoral Science Foundation Funded Project(Project No.2015 M571360)
文摘The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.
基金This research was conducted in Japan under the Research Planning of Japan-China Cooperation Project (the Research Project onTimber from Plantion Forests in China: JICA Project).
文摘The study illustrates differences between colors of poplar I-214 veneers dyed by reactive blue KN-R and 4 kinds of chemical reagents, and those of treated veneer exposed to UV-ray for 3 days. The results show there are some laws in poplar I-214 dyeing and UV-ray attenuation of each chemically treated veneer color. The chemical reaction carded out between cellulose or lignin on veneer surface and dye molecules when they met with. The capability of dyeing and discoloration of veneer is improved by control of dyeing technology, especially chemical treatments; being treated by acetylation and maleic anhydride protects dyed wood discoloration.
基金supported by the Natural Science Foundation of Heilongjiang Province, China (Grant No E200906)Scientific Foundation of Heilongjiang Office of Education (Grant No 11531035)the Young Founds of the National Natural Science Foundation of China (Grant No 51002040)
文摘Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing schorl dosage, temperature, initial H2O2 concentration, and by decreasing solution pH. When the raw schorl and the schorl samples sintered at 750°C, 850°C, 950°C and 1050°C were used as catalyst in Fenton-like system, the MO discoloration ratios obtained were 82%, 31%, 30%, 31% and 7%, respectively. XRD results showed that samples sintered at 750°C, 850°C and 950°C had no change in structure and still held the crystal structure of schorl and quartz, but, the content of schorl crystal decreased. Whereas, schorl crystal completely disappeared in the sample sintered at 1050°C and two new crystal phases of hematite and spinel were formed, which resulted in disappearance of the spontaneous ‘electrostatic poles’. Hence, it was inferred that the electrostatic field of schorl crystal could enhance the MO discoloration by schorl-catalyzed Fenton-like reaction.
基金Chinese National Key Technologies R & D Item (2001BA506B04-04).
文摘This paper reviews the mechanisms, types, compositions, affecting factors, prevention and remediable treatments of wood discoloration, and especially puts forward the biological control against wood stain and wood induced coloration. The authors think the followings are important: 1) Developing the low poisonous ornon-toxic, high-efficient and multi-functional anti-stain chemicalsis still an important research direction to control wood discoloration. 2) It is still very necessary to remove wood stain and restore wood original color and commercial value. 3) The biological control has little environmental pollution and its cost is low. Researches on its theories and application should be strengthened. 4) Wood color can be induced and turned to be the needed through heat treatment or ultraviolet irradiation without coloring materials, i.e. induced coloration, is agood idea to modulatewood, bamboo or rattan cane color. It is becoming a new study field.
