Learning shape and texture progression for young child face aging

Face aging (FA) for young faces refers to rendering the aging faces at target age for an individual, generally under 20s, which is an important topic of facial age analysis. Unlike traditional FA for adults, it is challenging to age children with one deep learning-based FA network, since there are deformations of facial shapes and variations of textural details. To alleviate the deficiency, a unified FA framework for young faces is proposed, which consists of two decoupled networks to apply aging image translation. It explicitly models transformations of geometry and appearance using two components: GD-GAN, which simulates the Geometric Deformation using Generative Adversarial Network; TV-GAN, which simulates the Textural Variations guided by the age-related saliency map. Extensive experiments demonstrate that our method has advantages over the state-of-the-art methods in terms of synthesizing visually plausible images for young faces, as well as preserving the personalized features.     

Stable Radicals with Protective Umbrellas Integrated on the Surface of 2D Layered Materials

Radicals are closely related to human life and health and have been widely used in biology, chemistry, functional materials, etc. However, the high reactivity, disorder, and short half-lives limit their wide applications. Therefore, it remains a great challenge to prepare stable and ordered radicals. Herein, radicals are prepared with protective umbrellas (diethylmethyleneamine, DEMA) that are integrated on the surface of 2D layered materials to isolate water and oxygen and enhance the stability of radicals. Taking 2D black phosphorus (BP) as an example: triethylamine reacts with dichloromethane to form quaternary ammonium salts with further Hoffmann elimination to produce DEMA radicals that could react with one electron of a lone pair electrons in P on the surface of BP to produce P radicals, which shows a prolonged half-life of 21 days at room temperature. First-principle calculations and electron paramagnetic resonance fitting confirm that the steric hindrance constructed by dense DEMA passivation layer acts as a protective umbrella and the 2D coupling of P radicals and other P atoms in 2D BP plane to enhance the stability and strong superexchange interaction of P radicals. Furthermore, it is a general strategy to produce stable radicals integrated on the 2D plane.     

A columnar regular-porous stainless steel reaction support with high superficial area for hydrogen production

To improve hydrogen production (HP) performance of regular-porous structure (RPS), a columnar RPS with small specific surface area and high superficial area is developed. A numerical simulation model of regular-porous stainless steel structure (RPSSS) is established. Subsequently, heat transfer performance, pressure loss, temperature, methanol concentration, H₂ concentration distributions and HP performance of the columnar RPSSS with small specific surface area and high superficial area and the body-centered cubic RPSSS with high specific surface area and small superficial area are compared. Then, temperature, methanol concentration, H₂ concentration distributions and HP performance of axial and longitudinal size-enlarged columnar RPSSSs are studied. The results show that compared to the body-centered cubic RPSSS, the columnar RPSSS has higher methanol conversion, larger H₂ flow rate and higher CO selectivity. Especially in the condition of 300 °C wall temperature and 12 mL/h methanol-water mixture injection rate (MWMIR), the methanol conversion, H₂ flow rate and CO selectivity of the columnar RPSSS are increased by 12.3%, 9.24% and 30%, respectively, indicating that the superficial area of RPSSS is more important for its HP performance compared to its specific surface area. Compared to the longitudinal size-enlarged columnar RPSSS, the axial size-enlarged columnar RPSSS has higher methanol conversion, larger H₂ flow rate and higher CO selectivity. This research work provides a new method for the optimization of hydrogen production reaction support (HPRS).     

Multi-color Q-switched of neodymium-doped all-fiber laser based on tungsten disulfide saturable absorber

Journal of Materials Science: Materials in Electronics - In this paper, a Q-switched and three-color operation of Neodymium-doped silica all-fiber laser is realized, in which, a few-layer...     

Exploring the activation mechanism of alcalase activity with pulsed electric field treatment: Effects on enzyme activity,spatial conformation,molecular dynamics simulation and molecular docking parameters

This study used alcalase derived from Bacillus licheniformis as the research object. We revealed the mechanism by which pulsed electric field (PEF) treatment increases alcalase activity. Alcalase is widely used in the food and brewing industries. The results showed that alcalase activity was increased by 11.26%, α-helix structure was reduced by 18.80%, and the number of hydrogen bonds in the molecule also was decreased from 309 to 305 at 10 kV/cm, which showed that the partial unfolding of the secondary structure was an important factor leading to an increase in alcalase activity. In contrast, fluorescence intensity and ζ-potential were reduced by 61.28% and 17.99%, respectively, and the binding energy between alcalase and casein in molecular docking increased by 15.07%, indicating that the tertiary structure was also a key factor in improving activity. Furthermore, molecular docking technology intuitively reflects that PEF treatment increased alcalase activity.     

Revealing the role of Ni2+ ions in inducing the synthesis of porous carbon balls: A novel substrate to enhance the Pt catalytic activity towards methanol-oxidation

Carbon-based materials have been often employed as electrocatalytic substrates because of their large surface area/highly porous structure. Similar to carbon substrates, the non-carbon related materials such as transition metals also play an important role in improving catalytic performance. However, the simultaneous synthesis and metallic functionalization of carbon substrates is a highly challenging issue. Herein, a hydrothermal method has been used for the preparation of Ni-functionalized porous carbon balls. The significant role of Ni²⁺ ions in the synthesis of porous carbon balls has been confirmed. The results of transmission electron microscopy indicate that, the as-prepared porous carbon balls were suitable for the dispersion of Pt nanoparticles with small particle size (less than 4 nm). In addition to providing the OH_ads species, the Ni can also modify the surface electronic structure of Pt. Electrochemical measurements results reveal that, under the strong interactions between Ni and Pt, the as-prepared porous carbon balls supported Pt nanoparticles (Pt/Ni-CB) catalyst possesses excellent electrocatalytic activity, stability and CO anti-poisoning capability towards methanol electrooxidation reaction (MOR). This work opens a novel idea for the construction of the metal functionalization of carbon substrates and their subsequent applications in other electrocatalytic reactions.     

Self-construction of pea-like Cu/Cu2S Mott-Schottky electrocatalyst for the oxygen evolution reaction

The speed of the oxygen evolution reaction seriously affects the hydrogen production efficiency of water electrolysis. Hence it is crucial to develop efficient and durable OER electrocatalysts. Construction of heterojunction catalysts is also one of the strategies to develop efficient catalysts. In this paper, a pea-like Cu/Cu₂S–C3 Mott?Schottky electrocatalyst was self-constructed by vapor deposition, while CF (copper foam) was used as substrate material and copper source, and thiourea was served as sulfur source. The built-in electric field is formed at the metal-semiconductor interface, which endows it with promising electrocatalytic performance. As the working electrode, the overpotentials of Cu/Cu₂S–C3 required to reach the current density of 10 and 50 mA cm^?2 were about 170 and 335 mV. The impact of the Mott-Schottky structure on the catalyst was also reflected in stability. The i-t tests of the sample Cu/Cu₂S–C3 were carried out under 10 and 60 mA cm^?2 and performed well.     

Reversible formation-melting of nano-crystals in supercooled oxyfluoride germanate liquids

The nanocrystals play a critical role in generating and affecting functionalities of glass materials. Therefore, scientists have made considerable efforts in clarifying microscopic mechanisms of nanocrystal formation in glass to obtain the desired type of nanocrystals. However, the phase transitions of nanocrystals during heating have not been well understood. Here we report on a discovery of the reversible melting-formation of nanocrystals in an oxyfluoride germanate glass during heating-cooling circles. Using a differential scanning calorimetry (DSC), we detected a striking endothermic event at 925 K during heating, after the glass underwent a DSC upscan to a temperature between 925–986 K and subsequent cooling. Based on Raman spectroscopy, X-ray diffraction and transmission electron microscopy, the endotherm is attributed to the melting of nano-crystal BaGeF₆ (˜20 nm). An exothermal response was observed at 890 K during the DSC downscan, implying the re-formation of BaGeF₆ nano-crystals. This suggests that the melting-formation of BaGeF₆ nano-crystals is a typical first-order transition.     

High-temperature electrical properties of polymer-derived ceramic SiBCN thin films fabricated by direct writing

The in situ temperature monitoring of hot components in harsh environments remains a challenging task. In this study, SiBCN thin-film resistance grids with thicknesses of 1.8 μm were fabricated on alumina substrates via direct writing. Owing to their dense microscopic morphology and extremely high graphitisation level, the produced SiBCN films exhibited large high-temperature oxidation resistance and electrical conductivity. The resistance–temperature, stability, and repeatability characteristics of these films were examined in an aerobic environment at temperatures up to 800 °C. The obtained results revealed that the thermistor resistance decreased monotonously with increasing temperature from room temperature to 800 °C. The SiBCN film resistance variations observed during repeated temperature cycling in the regions of 505–620 °C and 610–720 °C were 0.09% and 1.7%, respectively. The high cyclability and stability of the SiBCN thin film thermistor suggested its potential applicability for the in situ temperature monitoring of hot components in harsh environments.