Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
5,958
result(s) for
"Color Structure."
Sort by:
Naturally brilliant colour
Reveals artworks made using the world's brightest colour - Pure Structural Colour, recently derived from the metallic-like colours of Pollia berries, hummingbirds and butterflies.
Book
Robust Template Matching Using Multiple-Layered Absent Color Indexing
Color is an essential feature in histogram-based matching. This can be extracted as statistical data during the comparison process. Although the applicability of color features in histogram-based techniques has been proven, position information is lacking during the matching process. We present a conceptually simple and effective method called multiple-layered absent color indexing (ABC-ML) for template matching. Apparent and absent color histograms are obtained from the original color histogram, where the absent colors belong to low-frequency or vacant bins. To determine the color range of compared images, we propose a total color space (TCS) that can determine the operating range of the histogram bins. Furthermore, we invert the absent colors to obtain the properties of these colors using threshold hT. Then, we compute the similarity using the intersection. A multiple-layered structure is proposed against the shift issue in histogram-based approaches. Each layer is constructed using the isotonic principle. Thus, absent color indexing and multiple-layered structure are combined to solve the precision problem. Our experiments on real-world images and open data demonstrated that they have produced state-of-the-art results. Moreover, they retained the histogram merits of robustness in cases of deformation and scaling.
Journal Article
Tetraquarks and Pentaquarks from Quark Model Perspective
According to the classification of the quark model, the hadrons going beyond three-quark baryon and quark-antiquark meson pictures are called exotic hadrons. Many new hadrons have been observed since 2003, some of which exhibit exotic behaviors. There are a lot of excellent review articles on exotic hadrons available so far; the present article tries to focus on the recent experimental and theoretical progress on the exotic states from the perspective of the quark model. Although lattice quantum chromodynamics may give the final answer of the problem, the phenomenological models are still powerful tools to explore the exotic states and to provide insight on the phenomenology of hadrons. The spatial and color structures of multiquark states and the channel coupling calculation are emphasized through reviewing some bound states, molecular and color structure resonances. Finally, the unquench effects of some exotic states are reviewed. With the accumulation of experimental data on multiquark states and inspiration of underlying theory developments, more reasonable phenomenological models incorporating multi-body interactions and high Fock components to unify the description of normal hadrons and exotic hadrons are expectable.
Journal Article
Photonic Crystal Structures with Tunable Structure Color as Colorimetric Sensors
Colorimetric sensing, which transduces environmental changes into visible color changes, provides a simple yet powerful detection mechanism that is well-suited to the development of low-cost and low-power sensors. A new approach in colorimetric sensing exploits the structural color of photonic crystals (PCs) to create environmentally-influenced color-changeable materials. PCs are composed of periodic dielectrics or metallo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) by defining the allowed and forbidden photonic bands. Simultaneously, an amazing variety of naturally occurring biological systems exhibit iridescent color due to the presence of PC structures throughout multi-dimensional space. In particular, some kinds of the structural colors in living organisms can be reversibly changed in reaction to external stimuli. Based on the lessons learned from natural photonic structures, some specific examples of PCs-based colorimetric sensors are presented in detail to demonstrate their unprecedented potential in practical applications, such as the detections of temperature, pH, ionic species, solvents, vapor, humidity, pressure and biomolecules. The combination of the nanofabrication technique, useful design methodologies inspired by biological systems and colorimetric sensing will lead to substantial developments in low-cost, miniaturized and widely deployable optical sensors.
Journal Article
Designing eco-friendly pH-responsive Azo dyes for sustainable textile fabrics
Invention of high-performance, environmentally friendly disazo acid dyes (D
1
-D
4
) intended for sustainable textile coloring and pH-responsive sensing applications is reported in this study. Sulphanilic acid and other aromatic derivatives were used in simplified diazotization-coupling procedure to create dyes. Effective integration of azo and sulfonate groups, guaranteeing superior water solubility, was verified by structural characterization. Dyes created bright, high-affinity orange and red colors with remarkable wash and light fastness (ratings: 4–5) when applied to wool and nylon. λ
max
values in UV-vis spectra varied according to substituent location, from 479 to 485 nm. Notably, protonation-deprotonation balance drives Dye D
1
’s reversible, “smart” color shift from brown to pink in response to pH changes. Among synthesized dyes, D
1
showed a clear and reversible pH-responsive color change, going from brown to pink under increasingly acidic conditions, while D
3
showed mild pH sensitivity and dyes D
2
and D
4
remained color-stable throughout tested pH range of 2–4, displaying distinct chromatic stability profiles. Compared to nylon, the K/S and fastness qualities of wool materials were higher. These results show that synthesized dyes have great promise for creation of novel, pH-sensitive smart fabrics in addition to offering excellent technical performance and high fixing, which reduces environmental leaching.
Journal Article
Structural color for wood coloring: A review
The color, texture, and natural defects of wood are important factors affecting its commercial value. Change of wood’s surface color is a primary way to improve its value. This study analyzes and summarizes the development status and existing problems of the traditional wood dyeing process and induced discoloration process. It is proposed that color improvement with photonic crystal structure color is a clean and pollution-free ecological biomimetic coloring technology. Its research status in the fields of fiber, fabric, wood, wood-based panel surface color improvement, new coatings for wood, and lignocellulose nanocrystalline structure color film are reviewed. The following aspects were studied: 1) construction and mechanistic study of the wood surface structure color film, 2) light response and interface mechanistic study of the wood surface structure color film, 3) large-scale application technology study of the wood surface biomimetic structure color film, and 4) preparation and functional development of structural color films of lignocellulose nanocrystal.
Journal Article
Structural Color of Partially Deacetylated Chitin Nanowhisker Film Inspired by Jewel Beetle
Nanochitin was developed to effectively utilize crab shells, a food waste product, and there is ongoing research into its applications. Short nanowhiskers were produced by sonicating partially deacetylated nanochitin in water, resulting in a significant decrease in viscosity due to reduced entanglement of the nanowhiskers. These nanowhiskers self-assembled into a multilayered film through an evaporation technique. The macro- and nanoscale structures within the film manipulate light, producing vibrant and durable structural colors. The dried cast film exhibited green and purple stripes extending from the center to the edge formed by interference effects from the multilayer structure and thickness variations. Preserving structural colors requires maintaining a low ionic strength in the dispersion, as a higher ionic strength reduces electrostatic repulsion between nanofibers, increasing viscosity and potentially leading to the fading of color. This material’s sensitivity to environmental changes, combined with chitin’s biocompatibility, makes it well-suited for food sensors, wherein it can visually indicate freshness or spoilage. Furthermore, chitin’s stable and non-toxic properties offer a sustainable alternative to traditional dyes in cosmetics, delivering vivid and long-lasting color.
Journal Article
Switchable and Tunable Chemical/Structure Color in a Flexible Hierarchical Surface
Cephalopod skin is capable of fast color changing enabled by tunable skin transparency as well as structure color. Under this inspiration, herein, a flexible surface with unique hierarchical structure that integrates both transparency change in chemical color (optical scattering) and structure coloration (optical interfering) is developed by harnessing wrinkling instability, thanks to the interfacial Au catalysis in soft lithography. As a result, a hierarchical structure in terms of wrinkled film overlaid by nano‐dome array is obtained in the flexile surface. Experiments find that subject to biaxial strains from 0% to 60%, the hierarchical surface first experiences a transition from nontransparent to transparent owing to the flattening of the wrinkles and then exhibits iridescence structure color shifting from blue to red. The switchable and dynamical tunable mechanochromic characteristics are demonstrated in a smart window, offering potentials for developing flexible devices with optical multiple functionality. A flexible surface with hierarchical structure that integrates both chemical color (scattering in micro‐scale) and structure color change (interfering in nanoscale) is fabricated, by a one‐step soft lithography to harness wrinkling instability. Subject to biaxial strain, the hierarchical surface first experiences a transition from blurring to transparent and then exhibits iridescence in structure color redshift, offering a dynamic and switchable optical performance.
Journal Article
Influence of liquid properties of colloidal crystals to thermal stability of colloidal crystals on different substrate surfaces through heterogeneous nucleation
The effects of liquid properties, such as pH and conductivity, on the thermal stability of electrostatically interacting colloidal silica crystals generated from heterogeneous nuclei were investigated mainly by measuring relative reflection spectra. The melting behavior of the colloidal crystals was also investigated. The melting points of both negatively and positively charged 3-aminopropyltriethoxysilane (APS)-treated substrates with different surface charges increased or decreased with increasing or decreasing pH. For both substrates, pH 5.5 was the modulation point of the crystal melting, and the melting point increased with increasing pH. For the negatively charged substrate, the melting point increased slowly as the pH decreased from pH 5.5. Meanwhile, the melting point of the APS-treated substrate increased more with decreasing pH from 5.5 than that of the negatively charged substrate. The cationisation of the substrate increased with decreasing pH, resulting in stronger electrostatic interactions with the negatively charged colloidal crystals and enhanced thermal stability. Next, we investigated the size of colloidal crystal grains in sample bottles for different liquid properties, and the results show that at the higher pH, the smaller crystal grains, indicating that pH affects both the substrates and crystals. Moreover, the binding effect of the APS-treated substrate on the crystals became stronger at lower pH, thereby enhancing the thermal stability of the crystals.
Journal Article
High‐Brightness, Wide‐Gamut, and High‐Resolution Structural Colors via Ultrafast Laser Oxidation of Ti/TiO2 Films
The scalable fabrication of high‐brightness, wide‐gamut, and high‐resolution structural colors remains challenging due to the reliance on complex nanofabrication or coating techniques. Here, we demonstrate a facile and flexible approach to generating vivid structural colors via ultrafast laser processing of Ti–TiO2–Ti sandwich‐structured thin films. The multilayer design enables controlled oxidation with oxide thicknesses exceeding 200 nm under laser irradiation. Optical characterization reveals dual absorption enhancement peaks and a reflection enhancement peak in the visible spectrum. By tuning the accumulated laser fluence, we modulate the oxidation state of Ti and the optical properties of TiO2, achieving vibrant structural colors with high reflectivity and a color gamut exceeding 80% sRGB. Peak reflectance reaches 60%, and the highest color difference (ΔE) control precision is less than 3. Moreover, a resolution up to 30 000 DPI is attained. The laser‐induced structural colors exhibit excellent durability, passing standard tests for thermal stability and corrosion. This method enables direct patterning of high‐luminance colors and holds promise for applications in art, anti‐counterfeiting, signage, and flexible photonic devices. Ultrafast laser writing on titanium (Ti)–titanium dioxide (TiO2)–Ti sandwich films triggers controllable oxidation (〉200 nm) to create vivid, durable structural colors. The colors reach 〉 80% of the standard RGB (sRGB) gamut, up to 60% peak reflectance, and 30,000 dots per inch (DPI) resolution for art and anti‐counterfeiting.
Journal Article