Search

Current research on the compatibility between plastic liners utilized in Type IV high-pressure hydrogen storage containers and hydrogen remains insufficiently comprehensive. Therefore, further exploration into how the high-pressure hydrogen storage process influences the crystalline phase transition of polymers is essential to improve the applicability and safety of plastic lining materials. This study primarily investigated the preparation of polyamide 1012 (PA1012) and polyamide 11 (PA11) through rotational molding and injection molding, denoted as Roto-PA1012/Roto-PA11 and In-PA1012/In-PA11, respectively. Considering the operational parameters of the 70 MPa Type IV hydrogen storage tank, we conducted hydrogen cycling experiment using the long carbon chain polyamide (LCPA) liner materials and comprehensively analyzed the morphology, crystal structure, grain size, mechanical properties and hydrogen barrier properties of polyamide materials before and after hydrogen cycling. The results showed that after hydrogen cycling, no significant changes were observed in Roto-PA1012/Roto-PA11, while In-PA1012/In-PA11 demonstrated severe foaming. Rotational molding of LCPA maintained stable mechanical and hydrogen barrier properties throughout the hydrogen cycle, which can be attributed to the favorable thermodynamic stability of the α' form achieved during rotational molding, leading to uniform and stable crystal sizes. In conclusion, this study provides a theoretical foundation for future investigations into the molding process and material selection of high-barrier polymer liners, as well as the actual production and utilization of Type IV hydrogen storage tanks. • This research examines the effects of hydrogen circulation on the properties of long carbon chain polyamide (LCPA). • LCPA produced through rotational molding demonstrates better hydrogen compatibility compared to injection molding. • The study explores structural changes in LCPA during hydrogen absorption and desorption. [ABSTRACT FROM AUTHOR]

Within the genus Mycena, species exhibiting brownish basidiomata present considerable challenges in identification due to similar coloration. This study underscores the significance of pileipellis types and cheilocystidia characteristics as critical in delimiting brownish Mycena species. To clarify the principal taxonomic characters and their utility in distinguishing between brownish Mycena species, a morphological taxonomy and phylogenetic analysis were performed. Five new species from China were introduced and characterized through a comprehensive morphological anatomy and phylogenetic substantiation: M. campanulatihemisphaerica sp. nov., M. digitifurcata sp. nov., M. kunyuensis sp. nov., M. limitis sp. nov., and M. oryzifluens sp. nov. Discussions of these taxa are supplemented with morphological illustrations. The phylogenetic relationships were inferred using Bayesian Inference and Maximum Likelihood methods based on sequences from the internal transcribed spacer and the large subunit regions of nuclear ribosomal RNA. With the addition of these five new species, the worldwide count of brownish Mycena increases to 94, and a key to the 29 known species of brownish Mycena from China is presented. [ABSTRACT FROM AUTHOR]

Large tow carbon fiber (LTCF) has excellent performance and low cost. However, there are still many difficulties in the application of LTCFs, among which the problem of interfacial penetration is mainly solved. Building interfaces with sizing structures of fiber composites is an effective approach to achieve high performance. In this article, a water-based epoxy sizing agent suitable for LTCF fiber thermoset composites was studied. A comparison of the five LTCFs in this study shows that the wettability and contact angle of the sized LTCFs are significantly improved. In addition, the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) increased from 52.3 to 71.0 MPa (35%) and 36.4 to 54.6 MPa (50%), respectively. Compared with other imported LTCFs, domestic large-size LTCFs have a wide variety and a large number of surface functional groups, thereby improving their wettability and covalent bonding with the resin matrix. This work has reference significance for the practical application and industrial production of LTCFRP. [ABSTRACT FROM AUTHOR]

Weak interfacial bonding properties between thermoplastic liners and carbon fiber‐reinforced composites (CFRP) can easily lead to debonding failure, which is a major challenge in development of type IV composite hydrogen storage vessels. We optimized Box–Behnken design atmospheric‐pressure plasma process parameters for maximizing interfacial bonding properties between thermoplastic liner (PA11 liner) and CFRP using Design‐Expert software. From various designs, plasma process parameters, including time (t), nozzle‐to‐specimen distance (d) and gas flow rate (r) of treatment were selected for optimization to assess the effects of their interactions on climbing drum peel (CDP), flatwise tensile (FWT) and asymmetric double cantilever beams (ADCB). The CDP strength, FWT strength and strain energy release rate (GADCB) of untreated samples were 4.2 N·mm/mm, 0.26 MPa and 87.2 J/m2, respectively. After the plasma treatment, optimum process parameters of t = 200 s, d = 12.5 mm, and r = 700 L/h were used to achieve 33.8 N·mm/mm, 2.97 MPa and 1008.4 J/m2, respectively, which were 8.0, 11.4 and 11.6 times that of untreated PA11 surface, respectively. This method has the potential for guiding thermoplastic liner surface treatment of type IV hydrogen storage vessels before winding. [ABSTRACT FROM AUTHOR]

In order to reduce the errors caused by the idealization of the conventional analytical model in the transient planar source (TPS) method, a finite element model that more closely represents the actual heat transfer process was constructed. The average error of the established model was controlled at below 1%, which was a significantly better result than for the analytical model, which had an average error of about 5%. Based on probabilistic optimization and heuristic optimization algorithms, an optimization model of the inverse heat transfer problem with partial thermal conductivity differential equation constraints was constructed. A Bayesian optimization algorithm with an adaptive initial population (BOAAIP) was proposed by analyzing the influencing factors of the Bayesian optimization algorithm upon inversion. The improved Bayesian optimization algorithm is not affected by the range and individuals of the initial population, and thus has better adaptability and stability. To further verify its superiority, the Bayesian optimization algorithm was compared with the genetic algorithm. The results show that the inversion accuracy of the two algorithms is around 3% when the thermal conductivity of the material is below 100 Wm − 1 K − 1 , and the calculation speed of the improved Bayesian optimization algorithm is three to four times faster than that of the genetic algorithm. [ABSTRACT FROM AUTHOR]

In this research, a resin film of the MAM/EP blend curing system containing the triblock copolymer polymethyl methacrylate- b -poly-n-butyl acrylate- b -polymethyl methacrylate (MAM) was prepared. Such resin film was inserted into the interlaminar of rapid-curing composites to simultaneously improve both mode I, mode II fracture toughness and impact resistance. Both the Mode I and Mode II interlaminar fracture toughness of the composites were carefully investigated as a function of MAM content of the MAM/EP resin film (0, 20 and 40 phr@50 μm). A maximum improvement up to 109% and 70.2% on Mode I and Mode II fracture toughness, respectively was obtained with the introduction of the 40 phr@50 μm compared to the laminates with the introduction of the 0 phr@50 μm. Analysis of the fracture surfaces of the laminates elucidated that the distinctive improvement of the interlaminar fracture toughness could be attributed to the characteristic interlaminar structures of MAM in epoxy resin by self-assembly. The interleaved laminates also displayed an increase of 26.7% for the compression after impact (CAI) properties, and showed excellent impact resistance. The interlaminar shear strength (ILSS) of the composite was thereafter explored, which indicated slight enhancements to the strengths. [ABSTRACT FROM AUTHOR]

The rapid development of hydrogen fuel cells has been paralleled by increased demand for lightweight type IV hydrogen storage vessels with high hydrogen storage density, which raises the performance requirements of internal plastic liners. An appropriate manufacturing process is important to improve the quality of polymer liners. In this paper, DSC, WAXD, a universal testing machine and a differential pressure gas permeameter were used to investigate the effect of the cooling rate of the rotational molding polyamide 11 on the thermal, crystallization, mechanical and barrier properties. The cooling rate is formulated according to the cooling rate that can be achieved in actual production. The results suggest that two PA11 liner materials initially exhibited two-dimensional (circular) growth under non-isothermal crystallization conditions and shifted to one-dimensional space growth due to spherulite collision and crowding during the secondary crystallization stage. The slower the cooling process, the greater the crystallinity of the specimen. The increase in crystallinity significantly improved the barrier properties of the two PA11 liner materials, and the gas permeability coefficient was 2-3-fold higher than at low crystallinity. Moreover, the tensile strength, the tensile modulus, the flexural strength, and the flexural modulus increased, and the elongation at break decreased as the crystallinity increased. [ABSTRACT FROM AUTHOR]

Thermal expansion molding process (TEMP) is a new technology for integrated molding sandwich composites. However, the development of high‐performance expandable foam prepreg limits the scale applications of this technology. In this study, epoxy foam prepreg (M‐1) with expandable function was used to prepare foams with different expansion ratios via restricted foaming. Three suitable expansion ratios were determined to prepare foam sandwich composites by analyzing the density, bubble sizes, compressive strength, and expansion pressures of expandable foam. The maximum expansion pressure produced by four, six, and eight times of foam expansion were 251, 160, and 115 kPa, respectively. Tensile test and digital imaging computer technology confirmed that with the increase of foam expansion ratio, the strength decreased, but the plastic deformation ability increased. Failure modes such as foam matrix fracture, glass fiber mat fracture, and mutual‐slipping between the foam matrix and glass fiber mat occur during the stretching process. Finally, the PMI/M‐1 foam hybrid sandwich composites with three structures were prepared via the TEMP technology, which verified the feasibility of this technology in forming sandwich composites. [ABSTRACT FROM AUTHOR]

Catalytic, three‐component, cross‐electrophile reactions have recently emerged as a promising tool for molecular diversification, but studies have focused mainly on the alkyl‐carbonations of alkenes. Herein, the scope of this method has been extended to conjugated dienes and silicon chemistry through silylative difunctionalization of 1,3‐dienes with chlorosilanes and aryl bromides. The reaction proceeds under mild conditions to afford 1,2‐linear‐silylated products, a selectivity that is different to those obtained from conventional methods via an intermediary of H(C)‐η3‐π‐allylmetal species. Preliminary mechanistic studies reveal that chlorosilane reacts with 1,3‐diene first and then couples with aryl bromide. [ABSTRACT FROM AUTHOR]

This study optimized the laminate structure of a composite cylinder under the constraint of minimum layup thickness. Based on the progressive damage theory, a finite element model of the cylinder was established, and the NOL ring tensile test was used to verify the accuracy of the damage theory. The winding angle, the number of layers, and the helical/hoop ratio (the stacking sequence) were selected as the optimization factors, and the burst pressure value was used to evaluate the quality of the laminate structure. Then the orthogonal experiments were designed by RSM. Combined with FEA, the function model of the burst pressure of the gas cylinder and each optimization factor was established to obtain the optimal layering scheme, satisfying the minimum burst pressure. In addition, finite element analysis was used to verify the optimal scheme, demonstrating that the error of the burst pressure predicted by the quadratic model established by the response surface design was not more than 5%. This study provides a faster and more efficient optimization method for the optimization design of composite gas cylinder layers. [ABSTRACT FROM AUTHOR]

The cross‐electrophile coupling has become a powerful tool for C−C bond formation, but its potential for forging the C−Si bond remains unexplored. Here we report a cross‐electrophile Csp2‐Si coupling reaction of vinyl/aryl electrophiles with vinyl chlorosilanes. This new protocol offers an approach for facile and precise synthesis of organosilanes with high molecular diversity and complexity from readily available materials. The reaction proceeds under mild and non‐basic conditions, demonstrating a high step economy, broad substrate scope, wide functionality tolerance, and easy scalability. The synthetic utility of the method is shown by its efficient accessing of silicon bioisosteres, the design of new BCB‐monomers, and studies on the Hiyama cross‐coupling of vinylsilane products. [ABSTRACT FROM AUTHOR]

Poly vinyl acetate grafted calcium alginate hydrogel microspheres were prepared with bovine serum albumin (BSA) as molecular template. The microspheres exhibited homogeneous and core-shell structure according to different preparation strategy. The rebinding and swelling property of microspheres showed responsiveness toward ionic strength, temperature, and pH. It was found the highest separation factor of 1.85 and imprinting efficiency of 1.75 when the Ca2+ ionic strength was 1.25 and 0.34 mol/kg, respectively. The separation factor was found decreased as temperature grew from 29 to 45°C while the imprinting efficiency reached a peak value at about 37°C. Separation factor of BSA imprinted microspheres at different pH was also recorded and two peaks were found, which were considered to be caused by the similar swollen state due to ionic and covalent crosslinking structure of modified microspheres. The recognition responsiveness is suggested to be influenced by environmental effects due to the changing in imprints' configuration at different swollen states. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Simple Summary: Selenium Auricularia cornea culture (SAC) is a dried product via full fermentation, containing organic-Se, Auricularia cornea (AC) mycelium, and various metabolites of AC. The objective of this study was to evaluate whether SAC could effectively improve the health, growth, meat quality, and oxidative stability of meat in growing-finishing pigs. Currently, dietary SAC supplementation positively impacts growth performance and oxidative stability of fresh meat. Selenium Auricularia cornea culture (SAC) is a new source of organic selenium. Two experiments were conducted to determine the available energy of SAC fed to pigs and to evaluate the effects of dietary SAC supplementation on growth performance, serum biochemical profiles, fecal short chain fatty acids (SCFA), meat quality, tissue selenium concentration, and oxidative stability of fresh meat in growing-finishing pigs. In Experiment (Exp.) 1, 12 barrows with average body weight (BW) of 42.40 ± 5.30 kg were randomly allotted to two groups and fed the basal diet and SAC-supplemented diet, individually. In Exp. 2, 96 growing-finishing pigs (BW: 91.96 ± 7.55 kg) were grouped into four dietary treatments; each treatment contained six replicates with four pigs per replicate. The four treatments fed a control diet and three experimental diets supplemented with 0.6%, 1.2%, and 2.4% SAC, respectively. The trial lasted for 45 days. The results revealed that digestible energy (DE) of SAC was 11.21 MJ/kg. The average daily gain (ADG) was improved in pigs fed 1.2% and 2.4% SAC during day 24 to 45 and the overall period. Dietary 1.2% and 2.4% SAC supplementation had a lower F/G (p < 0.05) than the control diet during different stages. Dietary SAC supplementation increased fecal butyrate contents (p < 0.05), and pigs fed 1.2% and 2.4% SAC diets had a higher MCT1 mRNA expression (p = 0.04) in the colon. Pigs fed 2.4% SAC had higher GSH-Px contents (p < 0.05) in serum, liver, and longissimus dorsi muscle (LDM) than those in the control group. The 2.4% SAC-supplemented group revealed a higher Se content (p < 0.05) in LDM and a lower MDA concentration (p < 0.05) in fresh meat during the simulated retail display on day six. In conclusion, this study suggested that SAC was more effective in improving growth, enhancing the antioxidant status, depositing Se in muscle, and increasing meat oxidative stability of pigs. [ABSTRACT FROM AUTHOR]

Filament-wound composite tubular structures are frequently used in transmission systems, pressure vessels, and sports equipment. In this study, the failure mechanism of composite tubes reinforced with different fibres under low-velocity impact (LVI) and the radial residual compression performance of the impacted composite tubes were investigated. Four fibres, including carbon fiber-T800, carbon fiber-T700, basalt fibre, and glass fibre, were used to fabricate the composite tubes by the winding process. The internal matrix/fibre interface of the composite tubes before the LVI and their failure mechanism after the LVI were investigated by scanning electric microscopy and X-ray micro-computed tomography, respectively. The results showed that the composite tubes mainly fractured through the delamination and fibre breakage damage under the impact of 15 J energy. Delamination and localized fibre breakage occur in the glass fibre-reinforced composite (GFRP) and basalt fibre-reinforced composite (BFRP) tubes when subjected to LVI. While fibre breakage damage occurs globally in the carbon fibre-reinforced composite (CFRP) tubes. The GFRP tube showed the best impact resistance among all the tubes investigated. The basalt fibre-reinforced composite (BFRP) tube exhibited the lowest structural impact resistance. The impact resistance of the CFRP-T700 and CFRP-T800 tube differed slightly. The radial residual compression strength (R-RCS) of the BFRP tube is not sensitive to the impact, while that of the GFRP tube is shown to be highly sensitive to the impact. [ABSTRACT FROM AUTHOR]

To estimate postgrouting rock mass strength growth is important for engineering design. In this paper, using self-developed indoor pressure-grouting devices, 19 groups of test cubic blocks were made of the different water cement ratio grouting into the broken rock of three kinds of particle sizes. The shear strength parameters of each group under different conditions were tested. Then this paper presents a quantitative calculation method for predicting the strength growth of grouted broken rock. Relational equations were developed to investigate the relationship between the growth rates of uniaxial compressive strength (UCS), absolute value of uniaxial tensile strength (AUTS), internal friction angle, and cohesion for post- to pregrouting broken rock based on Mohr-Coulomb strength criterion. From previous test data, the empirical equation between the growth rate of UCS and the ratio of the initial rock mass UCS to the grout concretion UCS has been determined. The equations of the growth rates of the internal friction coefficient and UCS for grouting broken rock with rock mass rating (RMR) and its increment have been established. The calculated results are consistent with the experimental results. These observations are important for engineered design of grouting reinforcement for broken rock mass. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel catalytic oxidative desulfurization method was developed. [•] DBD air plasma was used to oxidize sulfur compounds in model fuel. [•] [BMIM]CH3COO was used as extracting agent. [•] MnO2 catalysts could effectively improve the desulfurization performance. [•] The sulfur removal of TS, BT, DBT and 4,6-DMDBT could reach above 90.0%. [Copyright &y& Elsevier]

Obesity is an unhealthy condition associated with various diseases characterized by excess fat accumulation. However, in China, the prevalence of obesity is 14.1%, and it remains challenging to achieve weight loss or resolve this issue through clinical interventions. Sanghuangpours vaninii (SPV) is a nutritional fungus with multiple pharmacological activities and serves as an ideal dietary intervention for combating obesity. In this study, a long-term high-fat diet (HFD) was administered to induce obesity in mice. Different doses of SPV and the positive drug simvastatin (SV) were administered to mice to explore their potential anti-obesity effects. SPV regulated weight, serum lipids, and adipocyte size while inhibiting inflammation and hepatic steatosis. Compared with the vehicle-treated HFD-fed mice, the lowest decreases in total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were 9.72%, 9.29%, and 12.29%, respectively, and the lowest increase in high-density lipoprotein cholesterol (HDL-C) was 5.88% after treatment with different doses of SPV. With SPV treatment, the analysis of gut microbiota and serum lipids revealed a significant association between lipids and inflammation-related factors, specifically sphingomyelin. Moreover, Western blotting results showed that SPV regulated the toll-like receptor (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway in HFD-diet mice, which is related to inflammation and lipid metabolism. This research presents empirical proof of the impact of SPV therapy on obesity conditions.

Cross-electrophile C-Si coupling has emerged as a promising tool for the construction of organosilanes, but the potential of this method remains largely unexplored. Herein, we report a C(sp 3 )-Si coupling of unactivated alkyl bromides with vinyl chlorosilanes. The reaction proceeds under mild conditions, and it offers a new approach to alkylsilanes. Functionalities such as Grignard-sensitive groups (e.g., acid, amide, alcohol, ketone, and ester), acid-sensitive groups (e.g., ketal and THP protection), alkyl fluoride and chloride, aryl bromide, alkyl tosylate and mesylate, silyl ether, and amine were tolerated. Incorporation of the -Si(vinyl)R 2 moiety into complex molecules and the immobilization of a glass surface by formed organosilanes were demonstrated.

Selenium Auricularia cornea culture (SAC) is a new source of organic selenium. Two experiments were conducted to determine the available energy of SAC fed to pigs and to evaluate the effects of dietary SAC supplementation on growth performance, serum biochemical profiles, fecal short chain fatty acids (SCFA), meat quality, tissue selenium concentration, and oxidative stability of fresh meat in growing-finishing pigs. In Experiment (Exp.) 1, 12 barrows with average body weight (BW) of 42.40 ± 5.30 kg were randomly allotted to two groups and fed the basal diet and SAC-supplemented diet, individually. In Exp. 2, 96 growing-finishing pigs (BW: 91.96 ± 7.55 kg) were grouped into four dietary treatments; each treatment contained six replicates with four pigs per replicate. The four treatments fed a control diet and three experimental diets supplemented with 0.6%, 1.2%, and 2.4% SAC, respectively. The trial lasted for 45 days. The results revealed that digestible energy (DE) of SAC was 11.21 MJ/kg. The average daily gain (ADG) was improved in pigs fed 1.2% and 2.4% SAC during day 24 to 45 and the overall period. Dietary 1.2% and 2.4% SAC supplementation had a lower F/G ( p < 0.05) than the control diet during different stages. Dietary SAC supplementation increased fecal butyrate contents ( p < 0.05), and pigs fed 1.2% and 2.4% SAC diets had a higher MCT1 mRNA expression ( p = 0.04) in the colon. Pigs fed 2.4% SAC had higher GSH-Px contents ( p < 0.05) in serum, liver, and longissimus dorsi muscle (LDM) than those in the control group. The 2.4% SAC-supplemented group revealed a higher Se content ( p < 0.05) in LDM and a lower MDA concentration ( p < 0.05) in fresh meat during the simulated retail display on day six. In conclusion, this study suggested that SAC was more effective in improving growth, enhancing the antioxidant status, depositing Se in muscle, and increasing meat oxidative stability of pigs.

The cross-electrophile coupling has become a powerful tool for C-C bond formation, but its potential for forging the C-Si bond remains unexplored. Here we report a cross-electrophile Csp 2 -Si coupling reaction of vinyl/aryl electrophiles with vinyl chlorosilanes. This new protocol offers an approach for facile and precise synthesis of organosilanes with high molecular diversity and complexity from readily available materials. The reaction proceeds under mild and non-basic conditions, demonstrating a high step economy, broad substrate scope, wide functionality tolerance, and easy scalability. The synthetic utility of the method is shown by its efficient accessing of silicon bioisosteres, the design of new BCB-monomers, and studies on the Hiyama cross-coupling of vinylsilane products., (© 2020 Wiley-VCH GmbH.)

The N-heterocyclic carbene-catalyzed asymmetric Michael/aldol/lactamization cascade reaction of enals and indole-derived enones for the synthesis of functionalized cyclopenta[3,4]pyrroloindolones with four consecutive stereogenic centers has been achieved. The products were obtained in good yield with high diastereoselectivity and excellent enantioselectivity.