Bamboo nanofibrillated cellulose（NFC） is widely existed in natural sources. Moreover, it has the dual characteristics of nano materials and biomass materials. It presents broad application prospects in the fields of degradable packaging materials and biological functional materials. However, the “natural anti degradation barrier”in bamboo fibers and the ordered crystalline structure region in cellulose supramolecules, leads to the defects of low enzymatic hydrolysis efficiency and long treatment time in the process, which limits the large-scale industrial preparation of bamboo NFC. In this study, NFC was preparated by biological enzyme and mechanical grinding, ozone pretreatment could be used to break the lignin structure in bamboo fiber and improve the accessibility of cellulase.The results showed that the size and water content of bamboo material had an important effect on the removal of bamboo lignin. Based on the ozone consumption rate and reaction time, the optimal pretreatment conditions was as follows: the particle size of bamboo 80/150 mesh and the water content 60%, respectively. After ozone pretreatment,the yield of bamboo NFC was increased from 74.2% to 84.6%. Ozone pretreatment is a green and environmentally friendly pretreatment process. It has little impact on subsequent enzymatic hydrolysis. Ozone pretreatment can effectively degrade lignin and a small amount of hemicellulose in bamboo and have little impact on cellulose. It owns a broad application prospect in the green preparation of bamboo NFC with low energy consumption.
In order to explore the influence of different kinds and shades of base colors on the color code detection in the overprinting process with the silver-free-edge laser paper used in the cigarette label gravure printing, the printing color group and printing color sequence process of gravure cigarette label products were analyzed in this study.And compared and screened from the printing ink color library, blue was selected as the baseline color block. The feasibility of taking blue as the base color block was preliminarily verified by simulation test analysis of the selected base color block. Finally, the computer experiment was carried out to verify. The results showed that selecting blue base color block can meet the requirements of normal overprint production of cigarette label. And according to 20months the statistics of paper use, compared with the laser paper with silver edge, the improvement can save 1.616%of the average amount of cigarette label paper. The study proves that the blue base color block has good feasibility in actual machine production, which successfully solves the problem that laser paper needs silver edge to realize color standard registration, and saves the raw material cost of cigarette label printing.
With the rapid development of additive manufacturing technology, 3D printed Braille has started to attract attention. In this study, a solvent-free hybrid photosensitive resin was selected and a UV light-curing printer with a light source wavelength of 405nm was used for Braille printing. In order to obtain the best Braille print quality, five printing parameters, namely layer height, basic forming time, single layer printing time, adhesion layer and filling density, were set during the printing process to comprehensively evaluate the quality of the printed Braille in terms of dimensional accuracy, friction resistance, environmental resistance, and roughness. The orthogonal test method was used to analyse the five printing parameters. The best quality of Braille was obtained with a layer height of 0.05mm,a basic forming time of 8s, a single layer printing time of 65s, 5 layers of adhesion and a filling density of 70%. The results showed that convex Braille printing can be realized by stereo lithography appearance technology, and the printed Braille has good identification, waterproof, corrosion protection and wear resistance.
In order to enhance the transfer printing effect on the surface of three-dimensional products, in this study,the preparation of three-dimensional transfer printing plate by laser plate-making technology and three-dimensional printing technology was explored, and the possibility of transfer printing plate using in the color printing on the surface of three-dimensional products through transfer printing technology was verified. Firstly, the best laser printing parameters were determined by the orthogonal test. Secondly, the pre-marking on the photosensitive resin plate and the metal plate was test. Then the three-dimensional transfer printing plate was prepared, and finally the printing effect of the printing plate transfer to the three-dimensional products was observed. The experiment results showed that the three-dimensional transfer printing plate of metal had better effect than that of photosensitive resin, and the best parameters of plate making were laser power of 50%, speed of 250mm/s, Q release time of 1μs, Q frequency of 20kHz, marking time of 1 and screening lines of 75 line/inch in gray dot matrix marking made, and the marking height was adjusted with the height of three-dimensional transfer printing plates. The three-dimensional transfer printing plates made with this study method is feasible for color printing on the surface of three-dimensional products.
In this study,the problems and user experience of intangible cultural heritage APPs were analyzed.Then,the interaction elements and levels of APP design were determined by questionnaire method,and the combination scheme was constructed by orthogonal experimental method.The design of the interactive interface of an intangible cultural heritage APP were studied by conjoint analysis method.Finally,the case of the Dunhuang culture APP was shared.This study will enable the designers to better understand the users' preferences for the interactive interface of intangible cultural heritage APPs,improve the user experience and adhesiveness,so as to achieve the purpose of spreading intangible cultural heritage,and provide design ideas for similar APPs interface design.
Polymethyl methacrylate（PMMA） microcapsules were fabricated by a solvent evaporation method as the carrier of cholesteric liquid crystal（CLC）. Three types of structural colors, red, green and blue, were obtained by controlling the content of chiral dopant in CLC. The influences of core/wall material mass ratio, emulsifying and stirring speed on the morphology, size, structural color and other properties were investigated in this study.Moreover, by doping organic dye molecules of triplet-triplet annihilation upconversion（TTA-UC） system,including the sensitizer Platinum octaethylporphyrin（PtOEP） and the annihilator 9,10-diphenylanthracene（DPA）,the microcapsules could achieve blue UC emission under the excitation of a 532nm continuous wave laser, and blue fluorescence could also be achieved under the excitation of ultraviolet（UV） light by doping DPA only. The microcapsules could be patterned through a spray coating method and applied for multimode anticounterfeiting by the combination of CLC structural color, UV excited fluorescent emission and green laser excited UC emission, which could display three different types of colored or luminescent patterns. This multi-function microcapsule technology shows a promising prospect in the field of anticounterfeiting packaging.
In this study, a color image watermarking algorithm based on NSCT-DWT-SVD composite QR code chaotic encryption was proposed. Firstly, the watermark image composed of the four characters “Flight Academy” was QR coded by the encoder to generate the QR code watermark information. The watermark was encrypted with Logistic chaotic map. The original carrier image in RGB color space was converted into YUV color space. The component Y of the converted model was extracted. The component Y was performed the NSCT to generate the low frequency components. Then, the wavelet transform and SVD singular value decomposition were performed to obtain singular values. Finally, the encrypted QR code was superimposed on the decomposed singular value through the additive principle. The experiments showed that the peak PSNR obtained by the algorithm is 52.15dB, which guarantees the amount of information and concealment of the embedded watermark. The salt, pepper noise and the JPEG compression attack have an NC value of 1. Especially since the addition of NSCT ensures the translation invariance of the image, SVD improves the algorithm’s ability to resist rotation attacks.
Dispersion is a key index to determine the performance of pigments, which not only determines the wettability of the initial pigment particles, but also determines the coloring intensity of ink. In this study, a self-dispersed pigment particle which can be used for ink was prepared by chemical grafting reaction. Hydrophilic groups have been introduced into the surface of the pigment to stabilize the pigment, and the effects of the reaction temperature, reaction time and p-aminobenzoic acid mass fraction on the particle size and Zeta potential of the pigment were studied and the optimal reaction procedure was determined. The results showed that the prepared modified pigment particles had the best performance, when the reaction temperature was 25℃, the reaction time was 1.5h, and the p-aminobenzoic acid mass fraction was 15%. The average particle size of the modified particles was about 85nm, and the Zeta potential was about-34mV. The modified pigment has excellent self-dispersion, and can be stable without adding any dispersant in the preparation of ink.
For the phenomenon of image target tracking loss caused by adverse environmental factors in the continuous shooting of video images, a single target tracking algorithm for video images based on the combination of SDAE model and preference learning model was peoposed in this study. In SDAE model, the processing rules of convolutional neural network model were adopted, and the internal arrangement structure of SDAE stack de-noising self-coder was adjusted. The constructed preference learning model transforms the target tracking problem into the region size sorting problem of the overlapping part of the target image block, and completed the design of the sorting function, the preference relationship between samples, the tracking constraints and the support vector machine classifier. Compared with the four target tracking algorithms selected in the experiment, the results showed that this algorithm has certain advantages in the tracking the target success rate, the target tracking accuracy, and the system running time, and the target success rate and target tracking accuracy were about 89%.
With the development of semiconductor lighting technology and the popularity of human-oriented lighting concept, color preference and color discrimination of lighting have become the forefront of color quality research. In recent years, many scholars have carried out visual experiments and tried to construct models to accurately quantify the color quality of lighting. However, case studies in psychophysical research have inherent defects that cannot be applied to multiple scenes, so the two dimensions of color quality of lighting have not been quantified effectively for a long time in the past. In terms of solving this problem, a meta-analysis approach is adopted in the construction of color quality models of lighting. The main idea of this work is to reveal the maximum amount of visual perception patterns of lighting with more scientific analysis based on much larger dataset, and consequently to develop universal color quality models. In this paper, the research process of color preference of lighting and color discrimination of lighting was mainly reviewed, the latest research progress of the two dimensions of color preference of lighting and color discrimination of lighting at the present stage was introduced, and the prospects for future research were made,in order to provide references for the later research in this field.
