Bionic design of thin-walled bilinear tubes with excellent crashworthiness inspired by glass sponge structures.

In order to enhance energy absorption, this study draws inspiration from the diagonal bilinear robust square lattice structure found in deep-sea glass sponges, proposing a design for thin-walled structures with superior folding capabilities and high strength-to-weight ratio. Firstly, the crashworthiness of bionic glass sponge tube (BGSTO) is compared with that of equal-wall-thickness equal-mass four-X tube through both experiments and simulations, and it is obtained that the specific energy absorption of BGSTO is increased by 78.64%. And the crashworthiness of BGSTO is also most significant compared to that of multicellular tubes with the similar number of crystalline cells. Additionally, we found that the double-line spacing of the glass sponge can be freely adjusted without changing the material amount. Therefore, based on BGSTO, we designed two other double-line structures, BGSTA and BGSTB. Then with equal wall thickness and mass as a prerequisite, this study proceeds to design and compare the energy absorption properties of three bilinear thin-walled tubes in both axial and lateral cases. The deformation modes and crashworthiness of the three types of tubes with variable bilinear spacing (ßO/A/B) are comparatively analysed. The improved complex proportional assessment (COPRAS) synthesis decision is used to obtain that BGSTO exhibits superior crashworthiness over the remaining two kinds of tubes. Finally, a surrogate model is established to perform multi-objective optimization on the optimal bilinear configuration BGSTO selected by the COPRAS method.

Study on the factors affecting the mechanical properties of antler under quasi-static compression.

In the natural environment, antlers have a significant mechanical structure that protects the deer head from injury. In this paper, the mechanical properties of antlers were evaluated through quasi-static compression tests and microstructural observation of samples from antlers, and the relationship between the sampling position, load direction, and microstructure and their mechanical properties were investigated. Compression experiments confirmed that the tines had the strongest mechanical properties, followed by the main beams and finally the brow tines. The mechanical properties of the test specimens subjected to axial compression were higher than those of lateral compression. The axial load test of the longitudinal sample of the tine of the antler has the best mechanical properties. Its specific energy absorption is 51.33 J/g, the peak crushing force is 1.26 kN, and the mean crushing force is 1.47 kN. There are many tubular structures in the transverse sections of antlers, and the distribution of fibers in the vertical direction is laminar with alternating rows forming a helical structure. Tubular structures were found to be prevalent in some of the better biomechanical structures by comparison. Numerical modeling simulations to describe the effect of tubular structures on the mechanical properties of antlers. The simulation results show that the increase in the size of the tubular structure improves its energy absorption within the variation of a 20% increase in the size of the long and short axis. These findings provide a theoretical and experimental basis for the design of energy-absorbing structures. RESEARCH HIGHLIGHTS: In this paper, transverse and longitudinal samples were taken from the main beam, tine, and brow tine of antlers, and axial and lateral compression were carried out, respectively. In this paper, quasi-static compression experiments were carried out on antler samples to study the effects of sampling position, loading direction, and microstructure on antler mechanical properties. By means of microstructure observation and numerical modeling, it is determined that the size of the antler Havel tube has an effect on its mechanical properties.

Photocatalytic Unsymmetrical Diamination of Styrenes, Indoles, and Benzofurans Facilitated by Benzotriazolyl and Iminyl Radicals.

Utilizing energy transfer catalysis, this research employed the bifunctional reagents benzotriazole carboxylic acid oxime esters to simultaneously generate benzotriazole and imine radicals. The synthesis of two distinct C-N bonds in a single conversion is showcased through radical addition and radical-radical cross-coupling processes between benzotriazole carboxylic acid oxime ester and olefins. This process facilitates the intermolecular two-component unsymmetrical diamination reaction of olefins. Using this approach, more than 40 benzotriazole-containing molecules were successfully synthesized using styrene, indole, and benzofuran as acceptors, with yields ranging from moderate to excellent.

The Merger of Halogen Atom Transfer (XAT) and Energy Transfer Catalysis (EnT) for the Modular 1,2-Iminylalkylation of Diazenes.

The 1,2-iminylalkylation of diazenes using alkyl iodides in combination with an O-benzoyl oxime is reported. In this transformation, O-benzoyl oxime acted as a radical precursor and XAT mediator. In addition to common alkyl iodides, other alkyl iodides such as iodomethane, iodomethane-d3, trifluoroiodomethane, ethyl difluoroiodoacetate, and iodoalkanes containing unprotected hydroxyl and amide groups can also serve as C-radical precursors in the 1,2-iminylalkylation with electrophilic diazenes as radical acceptors.

Photoinduced Difunctionalization of Diazenes Enabled by N-N Radical Coupling.

In this study, a metal-free difunctionalization strategy for diazenes was developed using a range of bifunctionalization reagents. This strategy involves a unique N(sp3)-N(sp2) radical coupling between the hydrazine radical and the imine radical. More than 30 triazane core motifs were constructed by installing imines and various functional groups, including alkyl, phenyl, cyanoalkyl, and sulfonyl groups, on both ends of the nitrogen-nitrogen bond of diazenes in an efficient manner.

Photocatalytic Multicomponent 1,n-Carboimination with Alkyl Iodides and O-Benzoyl Oxime through EnT and XAT Processes.

In this study, we developed a strategy using commercially available alkyl iodides and O-benzoyl oxime to efficiently introduce alkyl and iminyl groups via energy transfer and halogen-atom transfer processes. We performed three-component 1,2-carboimination of olefins and four-component 1,4-carboimination across olefins and alkynes, resulting in the synthesis of over 60 nitrogen-containing molecules. Moreover, this transformation enables the synthesis of molecules with sensitive groups that were previously difficult to achieve.

Structure and mechanical properties of ladybird elytra as biological sandwich panels.

The armour of the ladybird, elytra, protect the body from injury and are well-adapted to flight. However, experimental methods to decipher their mechanical performances had been challenging due to the small size, making it unclear how the elytra balance mass and strength. Here, we provide insights to the relationship between the microstructure and multifunctional properties of the elytra by means of structural characterization, mechanical analysis and finite element simulations. Micromorphology analysis on the elytron revealed the thickness ratio of the upper lamination, middle layer and lower lamination is approximately 51:139:7. The upper lamination had multiple cross fibre layers and the thickness of each fibre layer is not the same. In addition, the tensile strength, elastic modulus, fracture strain, bending stiffness and hardness of elytra were obtained through in-situ tensile and nanoindentation-bending under the influence of multiple loading conditions, which also serve as references for finite element models. The finite element model revealed that structural factors such as thickness of each layer, angle of fibre layer and trabeculae are key to affecting the mechanical properties, but the effect is different. When the thickness of upper, middle and lower layers is the same, the tensile strength provided by unit mass of the model is 52.78% lower than that provided by elytra. These findings broaden the relationship between the structural and mechanical properties of the ladybird elytra, and are expected to inspire the development of sandwich structures in biomedical engineering.

The potential meat flavoring generated from Maillard reaction products of wheat gluten protein hydrolysates-xylose: Impacts of different thermal treatment temperatures on flavor.

Wheat gluten protein hydrolysates were prepared by Flavourzyme, followed by xylose-induced Maillard reaction at different temperatures (80 °C, 100 °C and 120 °C). The MRPs were subjected to analysis of physicochemical characteristics, taste profile and volatile compounds. The results demonstrated that UV absorption and fluorescence intensity of MRPs significantly increased at 120 °C, suggesting formation of a large amount of Maillard reaction intermediates. Thermal degradation and cross-linking simultaneously occurred during Maillard reaction, while thermal degradation of MRPs played a more predominant role at 120 °C. MRPs exhibited high umami and low bitter taste at 120 °C, accompanied by the high content of umami amino acids and low content of bitter amino acids. Furans and furanthiols with pronounced meaty flavor served as the main volatile compounds in MRPs at 120 °C. Overall, high temperature-induced Maillard reaction of wheat gluten protein hydrolysates and xylose is a promising strategy for the generation of potential plant-based meat flavoring.

Sugar reduction in beverages: Current trends and new perspectives from sensory and health viewpoints.

Sugar, as an essential component of beverages, not only provides sweetness in beverages but also plays a significant role in their flavor, texture, and preservation. In recent years, global sugar consumption has continued to increase, causing a variety of health concerns. Currently, there is growing awareness of the adverse effects of high-sugar consumption. Since beverages are the primary source of daily sugar intake, sugar reduction in beverages is imperative. In this work, the necessity of sugar reduction in beverages was first introduced. Furthermore, four primary sugar reduction strategies (direct sugar reduction, multi-sensory integration, sweeteners, and sweetness enhancers) employed in the beverage industry were systematically summarized. Each sugar reduction strategy was critically compared, while the current research progresses as well as challenges were discussed. The application of sweeteners is the most effective and widely used strategy for sugar reduction in spite of flavor and health concerns of sweeteners. Meanwhile, multi-sensory integration is also a promising strategy for sugar reduction. In addition, different evaluation methods (chemical, cell-based and sensory methods) for sweetness were overviewed. Given the current challenges of sugar reduction, the prospects of sugar reduction in beverages were also discussed. The present work can provide the current progress for sugar reduction in the beverage industry.

Interfacial Self-assembly of Organics/MXene Hybrid Cathodes Toward High-Rate-Performance Sodium Ion Batteries.

Conjugated quinones are promising cathode materials for sodium-ion batteries. However, the contemporary primary conjugated quinones cathodes still hold to limited capacity, poor rate performance and low cyclability, due to the poor electronic and ionic conductivity. Herein, a series of high-performance conjugated-quinones@MXene hybrid cathodes is constructed by an in situ polymerization-assembly strategy based on the hydrogen bond and S-Ti interaction. The PAQS@Ti3C2Tx MXene hybrid, as a typical example, exhibits sandwiched structure with intimate PAQS@MXene contact, resulting in efficient interfacial mass transfer. The assembled MXene is able to build interconnected conductive channels in the hybrid cathodes for continuous and fast electrons/ions transport, which is verified by both the experimental results and density functional theory (DFT) calculations. As a result, the optimal PAQS@MXene hybrid electrode delivers excellent electrochemical performances with high capacity (∼242 mA h g-1 at 100 mA g-1), superior fast-charge/discharge ability (∼148 and 121 mA h g-1 at 5 and 10 A g-1, respectively), and ultralong cycle life (capacity as high as 57 mA h g-1 after 9000 cycles at 5 A g-1), which are more superior to that of the pure PAQS electrodes. Besides, the analogous PPTS@Ti3C2Tx MXene hybrid cathode also shows better performances compared to the pure materials.

Iodine enrichment and the underlying mechanism in deep groundwater in the Cangzhou Region, North China.

The lack of information on the origin and behavior of iodine in deep groundwater restricts the development and use of groundwater resources. To address this issue, the Cangzhou region in the eastern North China Plain (NCP) was selected for a case study. In total, 296 deep groundwater samples were collected, their iodine concentrations were determined, and the distribution characteristics of iodine concentrations were analyzed. Iodine concentrations ranged from < 0.002 to 1.22 mg/L, with a mean of 0.19 mg/L; 42% of the samples had high iodine concentrations. The levels were higher in the east than in the west, and most of the samples with high iodine concentrations were obtained from sites east of the boundary between the Cangxian uplift and the Huanghua depression. The weathering and dissolution of iodine-bearing minerals and the leaching of marine sediments can facilitate iodine enrichment. In the Cangxian uplift, iodine was mainly a result of the conversion of organic iodine, while in the Huanghua depression, iodine enrichment was a factor of the conversion of IO3-. Overall, the main factors for the enrichment of iodine are the sedimentary environmental and the hydrodynamic conditions. Our results provide a theoretical basis to understand the occurrence of high iodine concentrations in deep groundwater.