Enzymatic extraction and functional properties of phosphatidylcholine from chicken liver.

An environmentally sustainable method to extract phosphatidylcholine (PC) from chicken liver (PCCL) and its functional properties were studied. The extraction times, enzymatic hydrolysis time, the solid-liquid ratio as well as types of enzymes (protamex proteinase and neutral proteinase) were investigated. Furthermore, the content of PCCL, emulsifying properties and solubilities of PCCL were also determined. The optimum conditions of extracting PCCL were found to be: reaction time of 3.75 h, enzymatic hydrolysis time of 85.22 min, 1: 3.15 (w/v) of solid-liquid ratio, using protamex proteinase, and the yield and concentration of PCCL was 88.92% and 0.89 mg/mL, respectively. Solubility and emulsifying properties of PCCL showed that the HLB value of PCCL was 10, and in ethanol and glycerol, the solubility of PCCL was 0.5850 g/mL and 0.0965 g/mL, respectively, which was shown to have good ethanol solubility and lipophilicity. From the perspective of green production and high-value utilization of by-products, PCCL could be used as a potential new lecithin source, providing ideas for the development and application of PC of animal origin.

General synthesis of 2D rare-earth oxide single crystals with tailorable facets.

Two-dimensional (2D) rare-earth oxides (REOs) are a large family of materials with various intriguing applications and precise facet control is essential for investigating new properties in the 2D limit. However, a bottleneck remains with regard to obtaining their 2D single crystals with specific facets because of the intrinsic non-layered structure and disparate thermodynamic stability of different facets. Herein, for the first time, we achieve the synthesis of a wide variety of high-quality 2D REO single crystals with tailorable facets via designing a hard-soft-acid-base couple for controlling the 2D nucleation of the predetermined facets and adjusting the growth mode and direction of crystals. Also, the facet-related magnetic properties of 2D REO single crystals were revealed. Our approach provides a foundation for further exploring other facet-dependent properties and various applications of 2D REO, as well as inspiration for the precise growth of other non-layered 2D materials.

Infinite possibilities of ultrathin III-V semiconductors: Starting from synthesis.

Ultrathin III-V semiconductors have been receiving tremendous research interest over the past few years. Owing to their exotic structures, excellent physical and chemical properties, ultrathin III-V semiconductors are widely applied in the field of electronics, optoelectronics, and solar energy. However, the strong chemical bonds in layers are the bottleneck of the two-dimensionalization preparation process, which hinders the further development of ultrathin III-V semiconductors. Some effective methods to synthesize ultrathin III-V semiconductors have been reported recently. In this perspective, we briefly introduce the structures and properties of ultrathin III-V semiconductors firstly. Then, we comprehensively summarize the synthetic strategies of ultrathin III-V semiconductors, mainly focusing on space confinement, atomic substitution, adhesion energy regulation, and epitaxial growth. Finally, we summarize the current challenges and propose the development directions of ultrathin III-V semiconductors in the future.

Effect of ultrasound assisted konjac glucomannan treatment on properties of chicken plasma protein gelation.

The effect of ultrasound assisted konjac glucomannan treatment on the properties of chicken plasma protein gelation was investigated in this study. There were four gelation groups as follows: untreated plasma protein gelation (Control), gelation added konjac glucomannan (KGG), gelation by ultrasound treatment alone (UG) and gelation added konjac glucomannan combined with ultrasound treatment (KGUG). The data showed that the gelation strength and water-holding capacity of the treated groups were significantly increased compared with those of Control. The strongest bonding water was present in KGUG, followed by KGG and UG in low-field nuclear magnetic resonance. The storage energy (G') and loss energy modulus (G″) of KGUG showed the largest rheological properties, and the G' value was higher than that of G″. Furthermore, the elastic and gelatinous properties of UG, KGG and KGUG played a dominant role in viscoelasticity. After konjac glucomannan addition, the particle size of KGG increased significantly. Compared with that of the Control and KGG, the average particle size of UG and KGUG decreased significantly after ultrasound treatment. The hydrophobicity and disulfide bonds mainly affected the formation of heat-induced gelation in these four groups. Furthermore, KGUG with the highest hydrophobicity and disulfide bonds revealed the best stability. Therefore, the gelation of chicken plasma protein by ultrasound assisted konjac glucomannan treatment had excellent gelling properties.

Theoretical Analysis of Blast Protection of Graded Metal Foam-Cored Sandwich Cylinders/Rings.

The blast resistance of a sandwich-walled cylinder/ring comprising two metal face-sheets and a graded metal foam core, subjected to internal air blast loading, is investigated. Analytical models are developed for the deformation of the sandwich cylinder with positive and negative gradient cores under internal blast loading. The deformation process is divided into three distinct phases, namely the fluid-structure interaction phase, core-crushing phase, and outer face-sheet deformation phase. Finite element modeling is performed using the Voronoi material model. The proposed analytical models are verified through finite element analysis, and reasonable agreement is observed between the analytical predictions and finite element results. The sandwich structures with high energy absorption capacity or low maximum radial deflection are satisfied for the protecting purpose of impact/blast resistance requirements. Typical deformation processes are classified and analyzed; the effects of explosive charge, face-sheet thickness, and core gradient on the structural response are also examined. The results indicate that both the deformation modes and the structural response of the cylinders are sensitive to the blast charge and core configuration. It is concluded that energy absorption capacity and maximum radial deflection are two conflicting goals for achieving high impact/blast resistance capability. An in-depth understanding of the behavior in sandwich-walled cylinders under blast impulse and the influence of the core configuration helps realize the advantages and disadvantages of using graded foam materials in sandwich structures and can provide a guideline for structural design.

Universal growth of ultra-thin III-V semiconductor single crystals.

Ultra-thin III-V semiconductors, which exhibit intriguing characteristics, such as two-dimensional (2D) electron gas, enhanced electron-hole interaction strength, and strongly polarized light emission, have always been anticipated in future electronics. However, their inherent strong covalent bonding in three dimensions hinders the layer-by-layer exfoliation, and even worse, impedes the 2D anisotropic growth. The synthesis of desirable ultra-thin III-V semiconductors is hence still in its infancy. Here we report the growth of a majority of ultra-thin III-V single crystals, ranging from ultra-narrow to wide bandgap semiconductors, through enhancing the interfacial interaction between the III-V crystals and the growth substrates to proceed the 2D layer-by-layer growth mode. The resultant ultra-thin single crystals exhibit fascinating properties of phonon frequency variation, bandgap shift, and giant second harmonic generation. Our strategy can provide an inspiration for synthesizing unexpected ultra-thin non-layered systems and also drive exploration of III-V semiconductor-based electronics.

Numerical Simulation on In-plane Deformation Characteristics of Lightweight Aluminum Honeycomb under Direct and Indirect Explosion.

Lightweight aluminum honeycomb is a buffering and energy-absorbed structure against dynamic impact and explosion. Direct and indirect explosions with different equivalent explosive masses are applied to investigate the in-plane deformation characteristics and energy-absorbing distribution of aluminum honeycombs. Two finite element models of honeycombs, i.e., rigid plate-honeycomb-rigid plate (RP-H-RP) and honeycomb-rigid plate (H-RP) are created. The models indicate that there are three deformation modes in the X1 direction for the RP-H-RP, which are the overall response mode at low equivalent explosive masses, transitional response mode at medium equivalent explosive masses, and local response mode at large equivalent explosive masses, respectively. Meanwhile, the honeycombs exhibit two deformation modes in the X2 direction, i.e., the expansion mode at low equivalent explosive masses and local inner concave mode at large equivalent explosive masses, respectively. Interestingly, a counter-intuitive phenomenon is observed on the loaded boundary of the H-RP. Besides, the energy distribution and buffering capacity of different parts on the honeycomb models are discussed. In a unit cell, most of the energy is absorbed by the edges with an edge thickness of 0.04 mm while little energy is absorbed by the other bilateral edges. For the buffering capacity, the honeycomb in the X1 direction behaves better than that in the X2 direction.

Dynamic Compressive Behaviors of Two-Layer Graded Aluminum Foams under Blast Loading.

Experimental and numerical analyses were carried out to reveal the behaviors of two-layer graded aluminum foam materials for their dynamic compaction under blast loading. Blast experiments were conducted to investigate the deformation and densification wave formation of two-layer graded foams with positive and negative gradients. The shape of the stress waveform changed during the propagation process, and the time of edge rising was extended. Finite element models of two-layer graded aluminum foam were developed using the periodic Voronoi technique. Numerical analysis was performed to simulate deformation, energy absorption, and transmitted impulse of the two-layer graded aluminum foams by the software ABAQUS/Explicit. The deformation patterns were presented to provide insights into the influences of the foam gradient on compaction wave mechanisms. Results showed that the densification wave occurred at the blast end and then gradually propagated to the distal end for the positive gradient; however, compaction waves simultaneously formed in both layers and propagated to the distal end in the same direction for the negative gradient. The energy absorption and impulse transfer were examined to capture the effect of the blast pressure and the material gradient. The greater the foam gradient, the more energy dissipated and the more impulse transmitted. The absorbed energy and transferred impulse are conflicting objectives for the blast resistance capability of aluminum foam materials with different gradient distributions. The results could help in understanding the performance and mechanisms of two-layer graded aluminum foam materials under blast loading and provide a guideline for effective design of energy-absorbing materials and structures.