Bionic Structural Coloration of Textiles Using the Synthetically Prepared Liquid Photonic Crystals.

The structural coloration of textiles with bionic photonic crystals (PCs) is expected to become a critical approach to the ecological coloration of textiles. Rapid and large-area preparation of PC structurally colored textiles can be achieved via self-assembly of high mass fractions of liquid photonic crystals (LPCs). However, the rapid and large-scale manufacturing of LPCs remains a challenge. In this work, the pH regulator is added in the process of emulsion polymerization to solve the problem of phase transformation caused by the thermal decomposition of the initiator to produce H+ , directly achieving 40 wt.% PS nanospheres in the dispersion. Then oligomers and small-molecule salts are removed from the system via dialysis, and the pre-crystallized LPC system is efficiently prepared. Adjusting the particle size and the mass fraction of nanospheres is shown to be an efficient way to control the optical properties of LPCs. The rapid and large-area preparation of PC structural color fabric and the patterned PC structural color fabric with an iridescent effect is implemented by using LPCs as the assembly intermediate. By constructing the encapsulation layer on the surface of the PC structural color fabric, the consistency of high structural stability and high color saturation of the PC is realized.

Constructing of Core-Satellite Structure Bimetallic MOFs for Synergistic Enhanced Adsorption-Photocatalytic Degradation.

Various industries generate a large amount of wastewater, which contains soluble organic compounds that can seriously jeopardize the environment and human health. Therefore, new photocatalytic materials with the function of efficiently degrading pollutants have become a research hotspot. In this research, bimetallic metal-organic frameworks (MOFs) with a core-satellite structure were prepared through a simple one-pot method in the presence of a polyvinylpyrrolidone structure-directing agent and crystal size. Also, the synergy of the adsorption-catalytic properties of the core-satellite structure bimetallic MOFs was achieved via the interaction of aluminum and iron groups. Meanwhile, the type I heterojunction structure based on MIL-53(Al@Fe)-OH realized the effective separation of the photogenerated carriers. Under the synergistic adsorption-catalytic degradation, the degradation efficiency of methylene blue (MB) was nearly 100% after adsorption (of 2 h) and photocatalysis (of 2 h), and the removal rate of MB still reached 90.43% after five cycles. This study provides a new strategy for the construction of bimetallic MOF structures for efficient adsorption-catalyzed degradation of environmental pollutants.

Collaborative Task Offloading and Service Caching Strategy for Mobile Edge Computing.

Mobile edge computing (MEC), which sinks the functions of cloud servers, has become an emerging paradigm to solve the contradiction between delay-sensitive tasks and resource-constrained terminals. Task offloading assisted by service caching in a collaborative manner can reduce delay and balance the edge load in MEC. Due to the limited storage resources of edge servers, it is a significant issue to develop a dynamical service caching strategy according to the actual variable user demands in task offloading. Therefore, this paper investigates the collaborative task offloading problem assisted by a dynamical caching strategy in MEC. Furthermore, a two-level computing strategy called joint task offloading and service caching (JTOSC) is proposed to solve the optimized problem. The outer layer in JTOSC iteratively updates the service caching decisions based on the Gibbs sampling. The inner layer in JTOSC adopts the fairness-aware allocation algorithm and the offloading revenue preference-based bilateral matching algorithm to get a great computing resource allocation and task offloading scheme. The simulation results indicate that the proposed strategy outperforms the other four comparison strategies in terms of maximum offloading delay, service cache hit rate, and edge load balance.

Structural Colored Fabric Based on Monodisperse Cu2O Microspheres.

Structural-colored fabrics have been attracting much attention due to their eco-friendliness, dyelessness, and anti-fading properties. Monodisperse microspheres of metal, metal oxide, and semiconductors are promising materials for creating photonic crystals and structural colors owing to their high refractive indices. Herein, Cu2O microspheres were prepared by a two-step reduction method at room temperature; the size of Cu2O microspheres was controlled by changing the molar ratio of citrate to Cu2+; and the size of Cu2O microspheres was tuned from 275 nm to 190 nm. The Cu2O microsphere dispersions were prepared with the monodispersity of Cu2O microspheres. Furthermore, the effect of the concentration of Cu2O microsphere and poly(butyl acrylate) on the structural color was also evaluated. Finally, the stability of the structural color against friction and bending was also tested. The results demonstrated that the different structural colors of fabrics were achieved by adjusting the size of the Cu2O microsphere, and the color fastness of the structural color was improved by using poly(butyl acrylate) as the adhesive.

Preparation of Patterned Photonic Crystals with High Fastness and Iridescence Effect via Resist-Screen Printing.

Patterned photonic crystals (PCs) have great application potential in the textile field owing to their attractive high-saturation iridescent effect. Herein, based on the idea of resist printing, a novel approach to constructing patterned photonic crystals via screen printing was designed and achieved. A colorless pattern with hydrophilic and hydrophobic difference was firstly prepared by screen printing using a hydrophilic polymer paste printed on a hydrophobic fabric, and then the PC structurally colored pattern was obtained through scrapping liquid photonic crystals (LPCs) on the fabric because the LPCs were spread and assembled in the hydrophilic pattern but resisted in the hydrophobic areas, so that to realize the rapid preparation of patterned PCs on the fabric surface. Once the contact angle difference (ΔCA) between the hydrophilic and hydrophobic areas exceeded 80, the "color paste" (that is, LPCs) did not stain the hydrophobic area at all after scrapping, and the assembled PCs pattern showed good contour sharpness and high-saturation iridescence effect. The complex multistructural color patterns on the fabrics were achieved by adjusting the size of nanospheres and using multistep printing and scrapping. The preparation of the protective layer on the PC surface effectively improved the structural stability of the patterned PCs while retaining the optical properties of the pattern. This patterned PCs preparation method was combined with a conventional responsive substance (rhodamine B) to obtain double anti-counterfeiting patterned PCs with the iridescence effect. The results suggested a promising future in both the highly efficient preparation of patterned PCs and the application of PCs in the anti-counterfeiting field.

Fabrication of Anatase TiO2/PVDF Composite Membrane for Oil-in-Water Emulsion Separation and Dye Photocatalytic Degradation.

At present, the types of pollutants in wastewater are more and more complicated, however, the multifunctional membrane materials are in short supply. To prepare a membrane with both high efficient oil-in-water emulsion separation performance and photocatalytic degradation performance of organic dyes, the bifunctional separation membrane was successfully prepared by electrostatic spinning technology of PVDF/PEMA and in situ deposition of anatase TiO2 nanoparticles containing Ti3+ and oxygen vacancies (Ov). The prepared composite membrane has excellent hydrophilic properties (WCA = 15.65), underwater oleophobic properties (UOCA = 156.69), and photocatalytic performance. These composite membranes have high separation efficiency and outstanding anti-fouling performance, the oil removal efficiency reaches 98.95%, and the flux recovery rate (FRR) reaches 99.19% for soybean oil-in-water emulsion. In addition, the composite membrane has outstanding photocatalytic degradation performance, with 97% and 90.2% degradation of RhB and AG-25 under UV conditions, respectively. Several oil-in-water separation and dye degradation experiments show that the PVDF composite membrane has excellent reuse performance. Based on these results, this study opens new avenues for the preparation of multifunctional reusable membranes for the water treatment field.

Fabrication of photo-Fenton self-cleaning PVDF composite membrane for highly efficient oil-in-water emulsion separation.

The anti-fouling performance of membranes is an important performance in the separation of oil/water. However, the membrane with anti-fouling performance will also have surface scaling phenomenon when it runs for a long time. Therefore, there is still a great demand for stain-resistant membranes with good self-cleaning ability and high flux recovery rate. Based on this, this paper firstly prepared a hydrophilic membrane with carboxyl group and carboxyl ion by blending poly(ethylene-alt-maleic anhydride) (PEMA) and polyvinylidene fluoride (PVDF), and then prepared a self-cleaning composite membrane by in situ mineralization of ß-FeOOH particles on the surface of the membrane for efficient oil-in-water emulsion separation. A large number of -COOH/COO- and ß-FeOOH particles on the membrane surface make the composite membrane have strong hydrophilic properties (WCA = 20.34°) and underwater superoleophobicity (UOCA = 155.10°). These composite membranes have high separation efficiency (98.8%) and high flux (694.56 L m-2 h-1 bar-1) for soybean oil-in-water emulsion. Importantly, the as-prepared membrane shows excellent flux recovery rate (over 99.93%) attributed to the robust photo-Fenton catalytic activity of ß-FeOOH, and the ß-FeOOH is chemically bonded to the as-prepared membrane, which makes the as-prepared membrane have good reusability. This work provides hope for the application of self-cleaning membranes in the construction of anti-fouling membranes for wastewater remediation.

Preparation of Acrylic Yarns with Durable Structural Colors Based on Stable Photonic Crystals.

Structural coloration of photonic crystals (PCs) is considered an ecological and environmental way to achieve colorful textiles. However, constructing PCs with obvious structural colors on traditional flexible yarns is still a great challenge. As a secondary structure that forms textiles, compared with fibers and fabrics, the yarns are rougher, hindering the construction of regular PCs. In this work, the flexible acrylic yarns with vivid structural colors, named PC-based structural color yarns, were prepared by constructing regular PCs via assembling poly(styrene-butyl acrylate-methacrylate) (P(St-BA-MAA)) colloidal microspheres on yarns. Specifically, the properties of P(St-BA-MAA) colloidal microspheres were investigated. The PCs with better structural stability and obvious structural colors were prepared by presetting the acrylic adhesive layer on yarns. Moreover, the color durability and color regulation methods of prepared PC-based structural color yarns were evaluated and discussed. The results showed that the P(St-BA-MAA) colloidal microspheres exhibited even particle sizes, excellent monodispersity, and a typical hard core-soft shell structure. And the glass-transition temperature (T g) of the microspheres was tested to be about 65.6 °C. The cationic acrylate regarded as a pretreatment agent could not only improve the combination between the PC layers and the yarns by acting as a "bridge" but also enhance the structural color effect by smoothing the yarn surface. The results showed that when the mass fraction of cationic acrylate was 3 wt %, the microspheres were beneficial to access regular PCs with obvious structural colors. The PCs with bright structural colors could be constructed on black acrylic yarns, and the colors of yarns were still bright after rubbing and washing tests, indicating that the prepared PC-based structural color yarns have good color fastness. Moreover, the color hue of PC-based structural color yarns could be regulated by adjusting the particle sizes and viewing angles. This study provides strategic support for the structural coloration of flexible materials.

Modal gain characteristics of a two-section InGaAs/GaAs double quantum well passively mode-locked laser with asymmetric waveguide.

Monolithic two-section InGaAs/GaAs double quantum well (DQW) passively mode-locked lasers (MLLs) with asymmetric waveguide, consisting of the layers of p-doped AlGaAs waveguide and no-doped InGaAsP waveguide, emitting at ~ 1.06 µm, with a fundamental repetition rate at ~ 19.56 GHz have been demonstrated. Modal gain characteristics, such as a gain bandwidth and a gain peak wavelength of the MLL, as a function of the saturable absorber (SA) bias voltage (Va) as well as the injection current of gain section (Ig), were investigated by the Hakki-Paoli method. With the increase of Va, the lasing wavelength and net modal gain peak of the MLL both exhibited red-shifts to longer wavelength significantly, while the modal gain bandwidth was narrowed. Both the net modal gain bandwidth and gain peak of the MLL followed a polynomial distribution versus the reverse bias at the absorber section. In addition, for the first time, it was found that Va had an obvious effect on the modal gain characteristics of the MLL.

Nerves of the mediastinum.

Knowledge of the anatomy of the mediastinal nerves is essential for the evaluation and surgical treatment of most thoracic neoplasms. Thorough knowledge of the normal anatomy of the mediastinal nerves and of their variants cannot be overestimated because nerve trauma during nerve anatomy is also important because mediastinal or lung tumors can locally infiltrate those nerves either directly or through nodal metastases, making them generally unresectable.