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In this paper, the derivative nonlinear Schr$ \ddot{\text{o}} $dinger equations with Legendre potential $ \textbf{i} u_{t}-u_{xx}+V(x)u+ \textbf{i} |u|^2u_{x} = 0 $ subject to certain boundary conditions was considered, where the potential function $ V(x) = -\frac{1}{2}-\frac{1}{4}\tan^2{x}, \; x\in(-\frac{\pi}{2}, \frac{\pi}{2}) $, has singularity. It was proved that the above equation admits several quasi-periodic solutions with two frequencies. For the boundary problem, we established that the first eigenvalue vanishes, which means that the Hamiltonian system has some degeneracy, and the frequencies are completely resonant. In addition, the unbounded perturbation implies that we have to solve the coupled homological equations with a large variable coefficient. The proof was based on a partial Birkhoff normal form technique and a new infinite-dimensional Kolmogorov-Arnold-Moser theorem. [ABSTRACT FROM AUTHOR]

Renal involvement of primary biliary cholangitis (PBC) usually presents as distal renal tubular acidosis. Proximal tubular (PT) dysfunctions in PBC were rarely reported with unclear clinicopathological characteristics and renal prognosis. We identified 11 cases of PBC with PT dysfunctions (PBC-PT). Their medical document, kidney pathology, and follow-up data were retrospectively reviewed and analyzed. The 11 PBC-PT patients were mainly middle-aged (57.8 ± 5.2 years) females (81.8%). Most of them were asymptomatic PBC (7, 63.6%) with a high prevalence of elevated serum immunoglobulin M (IgM, 81.8%) and G (IgG, 54.5%) levels. In the kidney, they had a mean estimated glomerular filtration rate (eGFR) level of 46.54 ± 23.03 ml/min/1.73m2, and 81.8% of them had eGFR below 60 ml/min/1.73m2. They showed different degrees of PT dysfunctions, including hyperuricosuria, hypouricemia, normoglycemic glycosuria, generalized aminoaciduria, hyperphosphaturia, and hypophosphatemia. Their kidney pathology showed tubulointerstitial nephritis with lymphoplasmacytic infiltrates, brush border defects, and proximal tubulitis. After glucocorticoids treatment, the PT dysfunctions manifesting as hypophosphatemia, hypouricemia, and renal glycosuria all recovered, and the eGFR levels were improved from 43.24 ± 19.60 ml/min/1.73m2 to 55.02 ± 21.14 ml/min/1.73m2 (p = 0.028), accompanied by significant improvements of serum IgM levels (from 5.97 ± 4.55 g/L to 2.09 ± 1.48 g/L, p = 0.019). The PT dysfunctions were rare in PBC patients, and glucocorticoids treatment could benefit the improvements of eGFR and tubular functions. [ABSTRACT FROM AUTHOR]

Background The use of home enteral nutrition (HEN) has increased enormously. HEN has been shown to decrease length of stays, improve clinical outcomes, and increase quality of life. Literature on HEN epidemiology has also sprouted recently. Nevertheless, studies on Chinese HEN users are hardly seen. The objective of this study was thus to describe the epidemiological characteristics of HEN users from a Chinese tertiary hospital in 2018. Methods Data were retrospectively analyzed using the personal patient profiles we created upon each HEN initiation. In the year of 2018, 2007 patients and a cumulative total of 3375 episodes were recorded. Results The median age was 61 (IQR 46-75) years, and 63 (IQR 49-75) for males and 55 (IQR 43-72) for females. The most frequent indication for HEN implementation was oncological diseases (35.8%), followed by digestive diseases (13.4%), and neurological diseases (9.0%). Overall, 90.0% of the episodes were prescribed for oral nutrition supplement (ONS) and 9.5% for tube feeding (TF). Majority (70.8%) of the episodes comprised standard commercial formula. Conclusions Our study revealed some fundamental epidemiological characteristics of Chinese HEN patients. This preliminary single-center study has multiple limitations but still possesses revelatory and referential significance for other Chinese practitioners in the field of HEN. In future, multicenter studies and qualified HEN registries are widely needed in China., Author(s): Qian You [sup.1] , Xuemei Li [sup.1] , Ya Ma [sup.1] , Lei Shi [sup.1] , Wen Hu [sup.1] Author Affiliations: (1) Department of Clinical Nutrition, West China Hospital, [...]

Dropwise condensation on hydrophobic surfaces, compared to filmwise condensation on hydrophilic surfaces, is considered to be an effective means to enhance heat transfer. However, the development of technologies for promoting dropwise condensation using hydrophobic coatings has remained challenging due to the potential trade-off between enhanced hydrophobicity and increased thermal resistance associated with thicker coatings. In this study, we reported the realization of enhanced condensation heat transfer with ultrathin chemical vapor deposition of hexagonal boron nitride coatings, while maintaining robust dropwise condensation with over 120 h. Our experimental results demonstrate a 4.6-fold improvement in the heat transfer coefficient compared with filmwise condensation on bare substrates. These findings suggest that hexagonal boron nitride holds promise as a surface coating for promoting dropwise condensation of water vapor, potentially impacting various fields that rely on efficient heat transfer processes. [ABSTRACT FROM AUTHOR]

In mass production, injection molding plays a vital role in manufacturing various parts with complex settings. As perfluoroalkoxy alkane (PFA) injection‐molded products are widely used in immersion system, dimensional quality needs more attention. However, there is limited research on the dimension defects of PFA injection‐molded products. This study focused on the influence of mold design and process parameters on PFA part shrinkage, using mold flow simulation and orthogonal testing separately. Several gate locations and sizes were simulated to minimize shrinkage in mold design. Displacements varied with gate locations, and shrinkage decreased with larger gate sizes. The Taguchi method analyzed process parameters' impact on shrinkage. The results indicated that the injection rate had the most significant effect on the shrinkage of tube length, while melt temperature, holding pressure, and screw speed affected the shrinkage of tubes' outside diameter. Different flow directions exhibited variance in shrinkage. Using max–min normalization, the two shrinkage values reached 0.00972, whereas the smallest value obtained in the orthogonal experiment was 0.1545 in run 3. Thus, optimizing mold design and process parameters were two effective methods to reduce shrinkage. This study reduced shrinkage and improved the quality of PFA injection molding parts for semiconductor systems. [ABSTRACT FROM AUTHOR]

Simple Summary: Ecological fishery management is one of the predominant approaches to lake ecological management in China; it involves the stocking of filter-feeding fish species to mitigate algal blooms. This strategy not only enhances water quality but also yields ecological benefits by fostering the growth of fish populations, thereby offering both ecological and economic advantages. Nonetheless, there is a scarcity of works in the literature addressing the effects on fish community dynamics and diversity in lakes subsequent to the cessation of ecological fishing practices. This study focuses on the initial changes observed in fish community composition and diversity following the cessation of an ecological fishery project in Qilu Lake, an eutrophic shallow lake situated in China. Ecological fishery projects aim to improve the water quality of eutrophication lakes by stocking filter-feeding fish species that feed on algae. The findings indicate a significant decline in the number of fish species, average individual size, and species diversity index following the cessation of fisheries-related activities (including fish stocking and fishing activities) due to the termination of the ecological fishery project in the lake. To preserve fish biodiversity and enhance water quality in Qilu Lake, it is recommended that policies be implemented to sustain the implementation of ecological fisheries projects, restore habitats for native fish species, and regulate the proliferation of small fish populations. The Qilu Lake is an eutrophic shallow lake located in Yunnan Province, China. An ecological fishery project was initiated in the lake from 2011 to 2021 to introduce filter-feeding fish species that feed on algae, with the aim of improving water quality. In January 2022, when the ecological fishery project expired, all fisheries-related activities (including fish stocking and fishing activities) ceased in the lake. To comprehensively evaluate the initial alterations in fish community structure and diversity resulting from the fishing cessation in the Qilu Lake, the present study conducted field surveys within the one year before the fishing cessation (referred to as BFC) and the one year after the fishing cessation (referred to as AFC). A total of twenty-one fish species were collected, including four native species. Four species were recorded in the lake for the first time, including Pelteobagrus fulvidraco, Pelteobagrus vachelli, Paramisgurnus dabryanus, and Hyporhamphus intermedius. The number of fish species decreased from 21 to 13 following the fishing cessation. The fishes collected in both BFC and AFC are mainly omnivorous-feeding and of bottom-dwelling habits. The mean size of the fishes in the AFC sample shows a significant decrease compared to those in BFC. After the fishing cessation, the Shannon–Wiener diversity index and Margalef richness index of the fish slightly declined. The fish community structure of the Qilu Lake exhibits a high degree of similarity to adjacent lakes in central Yunnan. Our study demonstrates a significant shift in the fish community of the Qilu Lake following the fishing cessation, one which may adversely impact the stability of the lake ecosystem. To enhance fish species diversity in the Qilu Lake, it is recommended that policies be implemented to promote the ecological fishery project and improve habitat restoration for native fish species, while also regulating fish community structure. [ABSTRACT FROM AUTHOR]

Heat stress (HS) causes severe economic losses in sheep industry worldwide. The objective of the present study was to investigate the effects of a herbal formula (HF) supplement on growth, digestibility, antioxidant capacity, and rumen microbes in fattening lambs under HS. The HF composed of four herbs was prepared based on the theory of compatibility of Chinese medicine "Jun-Chen-Zuo-Shi". Two-hundred forty 3-month weaned lambs (initial weight 36.61 ± 0.73 kg) were randomly allocated into four groups, supplemented 0% (Control), 0.5%, 1.0%, and 1.5% HF in diets. All lambs were exposed to HS conditions with 79.7 of average temperature–humidity index throughout an experimental period of 35 days. Growth performance, apparent digestibility, and antioxidant activities, involving antioxidant enzymes and heat shock proteins (HSPs), were measured at the end of trial, as well as microbial communities in bacteria and archaea. Results showed that 0.5% HF increased (P = 0.02) average daily gain by 13.80% and decreased feed-to-gain ratio (P = 0.03) by 14.68%, compared to control. With increasing HF doses, the digestibility of ether extract and acid detergent fiber demonstrated a cubical (P < 0.01) and quadratic (P = 0.03) relation, respectively; moreover, glutathione peroxidase and catalase activities demonstrated a quadratic increase (P < 0.01). Serum levels of HSP60, HSP70, and HSP90 for 0.5% HF were lower than that in control (P < 0.05). On the other hand, total volatile fatty acid, acetic acid, butyric acid, valeric acid, and isovaleric acid levels exhibited quadratic increases (P ≤ 0.01) with HF doses. From rumen microbes, the abundance and diversity of bacterial community were improved by HF supplements. Particularly for 0.5% HF group, the operational taxonomic units were the greatest among all groups. Compared to control, Prevotella abundance for HF supplements from 0.5 to 1.5% increased by 35.57 to 60.15%, and Succiniclasticum abundance demonstrated a quadratic pattern (P = 0.02) with doses. Additionally, Methanosphaera abundance in archaeal community raised by 0.2 to 3.3-folds when lambs were fed the HF additions of 0.5 to 1.5%. In summary, dietary HF supplements would contribute to alleviating HS in lambs, and our results suggest the optimal dose of 0.5% HF supplement in diet. [ABSTRACT FROM AUTHOR]

Music is integrated into daily life when listening to it, playing it, and singing, uniquely modulating brain activity. Functional near-infrared spectroscopy (fNIRS), celebrated for its ecological validity, has been used to elucidate this music–brain interaction. This scoping review synthesizes 22 empirical studies using fNIRS to explore the intricate relationship between music and brain function. This synthesis of existing evidence reveals that diverse musical activities, such as listening to music, singing, and playing instruments, evoke unique brain responses influenced by individual traits and musical attributes. A further analysis identifies five key themes, including the effect of passive and active music experiences on relevant human brain areas, lateralization in music perception, individual variations in neural responses, neural synchronization in musical performance, and new insights fNIRS has revealed in these lines of research. While this review highlights the limited focus on specific brain regions and the lack of comparative analyses between musicians and non-musicians, it emphasizes the need for future research to investigate the complex interplay between music and the human brain. [ABSTRACT FROM AUTHOR]

Aims: To examine whether functional connectivity (FC) of the occipital gyrus differs between patients with Parkinson's disease (PD) motor subtypes and healthy controls (HCs). Methods: We enrolled 30 PD patients exhibiting tremor dominance (TD), 43 PD patients with postural instability and gait disturbance (PIGD), and 42 HCs. The occipital gyrus was partitioned into six areas of interest, as seed points, via the Anatomical Automatic Labeling template to compare the FC of the three groups and analyze the relationship of FC with clinical scales. Results: Compared with the PIGD group, the TD group showed increased FC between the left superior occipital gyrus (SOG.L) and right median cingulate and paracingulate gyri (DCG.R)/right paracentral lobule/bilateral inferior parietal, but supramarginal and angular gyri; the left middle occipital gyrus (MOG.L) and left posterior cingulate gyrus (PCG.L); the MOG.R and SOG.L/right calcarine fissure and surrounding cortex/DCG.R/PCG.L/right cuneus; the left inferior occipital gyrus (IOG.L) and right caudate nucleus; and the IOG.R and PCG.L. Conclusion: Differentiated FC between the occipital gyrus and other brain areas within the PD motor subtypes, which may serve as neural markers to distinguish between patients with TD and PIGD PD. [ABSTRACT FROM AUTHOR]

Arthrobotrys oligospora is a typical nematode-trapping (NT) fungus, which can secrete food cues to lure, capture, and digest nematodes by triggering the production of adhesive networks (traps). Based on genomic and proteomic analyses, multiple pathogenic genes and proteins involved in trap formation have been characterized; however, there are numerous uncharacterized genes that play important roles in trap formation. The functional studies of these unknown genes are helpful in systematically elucidating the complex interactions between A. oligospora and nematode hosts. In this study, we screened the gene AOL_s00004g24 (Ao4g24). This gene is similar to the SWI/SNF chromatin remodeling complex, which was found to play a potential role in trap formation in our previous transcriptome analysis. Here, we characterized the function of Ao4g24 by gene disruption, phenotypic analysis, and metabolomics. The deletion of Ao4g24 led to a remarkable decrease in conidia yield, trap formation, and secondary metabolites. Meanwhile, the absence of Ao4g24 influenced the mitochondrial membrane potential, ATP content, autophagy, ROS level, and stress response. These results indicate that Ao4g24 has crucial functions in sporulation, trap formation, and pathogenicity in NT fungi. Our study provides a reference for understanding the role of unidentified genes in mycelium growth and trap formation in NT fungi. [ABSTRACT FROM AUTHOR]

Diagnosing agricultural machinery faults is critical to agricultural automation, and identifying vibration signals from faulty bearings is important for agricultural machinery fault diagnosis and predictive maintenance. In recent years, data–driven methods based on deep learning have received much attention. Considering the roughness of the attention receptive fields in Vision Transformer and Swin Transformer, this paper proposes a Shift–Deformable Transformer (S–DT) network model with multi–attention fusion to achieve accurate diagnosis of composite faults. In this method, the vibration signal is first transformed into a time–frequency graph representation through continuous wavelet transform (CWT); secondly, dilated convolutional residual blocks and efficient attention for cross–spatial learning are used for low–level local feature enhancement. Then, the shift window and deformable attention are fused into S–D Attention, which has a more focused receptive field to learn global features accurately. Finally, the diagnosis result is obtained through the classifier. Experiments were conducted on self–collected datasets and public datasets. The results show that the proposed S–DT network performs excellently in all cases. With a slight decrease in the number of parameters, the validation accuracy improves by more than 2%, and the training network has a fast convergence period. This provides an effective solution for monitoring the efficient and stable operation of agricultural automation machinery and equipment. [ABSTRACT FROM AUTHOR]

Rationale: The mechanisms underlying major depressive disorder (MDD) in children and adolescents are unclear. Metabolomics has been utilized to capture metabolic signatures of various psychiatric disorders; however, urinary metabolic profile of MDD in children and adolescents has not been studied. Objectives: We analyzed urinary metabolites in children and adolescents with MDD to identify potential biomarkers and metabolic signatures. Methods: Here, liquid chromatography-mass spectrometry was used to profile metabolites in urine samples from 192 subjects, comprising 80 individuals with antidepressant-naïve MDD (AN-MDD), 37 with antidepressant-treated MDD (AT-MDD) and 75 healthy controls (HC). We performed orthogonal partial least squares discriminant analysis to identify differential metabolites and employed logistic regression and receiver operating characteristic analysis to establish a diagnostic panel. Results: In total, 143 and 71 differential metabolites were identified in AN-MDD and AT-MDD, respectively. These were primarily linked to lipid metabolism, molecular transport, and small molecule biochemistry. AN-MDD additionally exhibited dysregulated amino acid metabolism. Compared to HC, a diagnostic panel of seven metabolites displayed area under the receiver operating characteristic curves of 0.792 for AN-MDD, 0.828 for AT-MDD, and 0.799 for all MDD. Furthermore, the urinary metabolic profiles of children and adolescents with MDD significantly differed from those of adult MDD. Conclusions: Our research suggests dysregulated amino acid metabolism and lipid metabolism in the urine of children and adolescents with MDD, similar to results in plasma metabolomics studies. This contributes to the comprehension of mechanisms underlying children and adolescents with MDD. [ABSTRACT FROM AUTHOR]

Background: Many personnel respond to natural disasters like earthquakes and tsunamis and frequent public health events like Ebola and COVID-19. However, research on emergency assistance personnel remains limited. This study aims to describe the perceived well-being among responders deployed in isolated or emergency international missions while providing practical references to intervene in developing similar missions. Methods: For this qualitative phenomenological study, purposive sampling was used following the principle of maximum differentiation to select personnel deployed on an emergency mission for over a year. Data collection continued until data saturation. Phenomenologically semi-structured interviews helped explore the physical and psychological status of the participants with Colaizzi's method. Results: Eleven personnel were interviewed after the mission, with four major themes being identified: 'perceived somatic change,' 'perceived emotional change,' 'behavioral change,' and 'coping with perceived change.' Conclusions: The mental health status of the emergency assistance personnel was affected by multiple factors from external and internal environments. The current study explored the physical and psychological feelings and emotions of emergency assistance personnel during an emergency mission. The study provided a practical reference for health management under similar missions. Registrations: Not registered. [ABSTRACT FROM AUTHOR]

Background: GATA1-related cytopenia (GRC) is characterized by thrombocytopaenia and/or anaemia ranging from mild to severe. Haematopoietic stem cell transplantation (HSCT) is a healing therapeutic choice for GRC patients. We identified a novel pathogenic variant (GATA1: c.1019delG) in a boy with GATA1-related cytopenia. Then we performed preimplantation genetic testing (PGT) in this GRC family. After a mosaic embryo transfered, a healthy and HLA-compatible with the proband baby was delivered. Case presentation: The proband is a 6-year-old boy who was diagnosed to have transfusion-dependent anaemia since 3 year old. Whole-exome sequencing (WES) showed that the proband has a hemizygous variant c.1019delG in GATA1, which is inherited from his mother. His parents decided to undergo PGT to have a health and HLA-compatible offspring. After whole genome amplification (WGA) of biopsied trophectoderm (TE) cells, next generation sequencing (NGS)-based PGT was preformed to analyse embryos on chromosomal aneuploidy, target mutation and HLA typing. There were 3 embryos HLA-matched to the proband. The genotypes of the 3 embryos were heterozygous variant, hemizygous variant, normal respectively. After a heterozygous, mosaic partial trisomy (chr)16, and HLA-matched embryo transfer, a healthy baby was delivered and whose HSCT is compatible with the proband. Conclusions: NGS-based PGT-HLA is a valuable procedure for the treatment of GATA1-related cytopenia caused by GATA1 variants, or other haematological disorders, oncological and immunological diseases. Furthermore, our study reconfirms that mosaic embryos transfer would bring healthy offspring. [ABSTRACT FROM AUTHOR]

Key message: BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance in Arabidopsis roots. The formative divisions of cortex/endodermis initials (CEIs) and CEI daughter cells (CEIDs) in Arabidopsis roots are coordinately controlled by the longitudinal auxin gradient and the radial SHORT ROOT (SHR) abundance. However, the mechanism underlying this coordination remains poorly understood. In this study, we demonstrate that BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance. Mutations in BIG gene repressed cell cycle progression, delaying the formative divisions within the ground tissues and impairing the establishment of endodermal and cortical identities. In addition, we uncovered auxin’s suppressive effect on BIG expression, triggering CYCLIND6;1 (CYCD6;1) activation in an SHR-dependent fashion. Moreover, the degradation of RETINOBLASTOMA-RELATED (RBR) is jointly regulated by BIG and CYCD6;1. The loss of BIG function led to RBR protein accumulation, detrimentally impacting the SHR/SCARECROW (SCR) protein complex and the CEI/CEID formative divisions. Collectively, these findings shed light on a fundamental mechanism wherein BIG intricately coordinates the interplay between SHR/SCR and auxin, steering ground tissue patterning within Arabidopsis root tissue. [ABSTRACT FROM AUTHOR]

In this paper, the non-autonomous fractional evolution inclusions of Clarke subdifferential type in a separable reflexive Banach space are investigated. The mild solution of the non-autonomous fractional evolution inclusions of Clarke subdifferential type is defined by introducing the operators ψ (t , τ) and ϕ (t , τ) and V(t), which are generated by the operator - A (t) and probability density function. Combined the measure of non-compactness, some properties of the Clarke subdifferential with fixed point theorem of κ - condensing multi-valued maps, a new existence result of mild solution is established. Moreover, an existence result of optimal control pair for the Lagrange problem is also derived. The results obtained in this paper extend the study of fractional autonomous evolution equations to the non-autonomous fractional evolution inclusions. Finally, a fractional partial differential inclusion with control is provided to illustrate the applications of the obtained main results. [ABSTRACT FROM AUTHOR]

Cu catalysts with different compositions and different Cu and promoter contents were prepared by precipitation‐gel method and studied for the selective hydrogenation of syngas or biomass‐based diethyl malonate (DEM) to valuable 1,3‐propanediol (1,3‐PDO). The Ga‐promoted 70Cu6Ga/SiO2 catalyst was found to exhibit the highest catalytic performance, achieving 100 % DEM conversion and 76.6 % 1,3‐PDO selectivity under reaction conditions of 160 °C and 8 MPa H2. The 70Cu6Ga/SiO2 bimetallic catalyst also presented obviously better stability than that of the monometallic 70Cu/SiO2 catalyst in a continuous flow reactor over 180 h time‐on stream. Characterization results showed that the incorporation of Ga increased the interaction between Cu and Ga species, hindered the full reduction of Cu2+ species, and thus increased the proportion of Cu+ and the number of Lewis acidic sites on the catalyst surface. The synergistic effect between Cu0 and Cu+ enhanced the adsorption and activation of ester carbonyl groups and their subsequent hydrogenation, eventually contributed to the outstanding performances of the CuGa/SiO2 bimetallic catalysts. [ABSTRACT FROM AUTHOR]

SUMMARY: The increased soil salinity is becoming a major challenge to produce more crops and feed the growing population of the world. In this study, we demonstrated that overexpression of OsDIR55 gene enhances rice salt tolerance by altering the root diffusion barrier. OsDIR55 is broadly expressed in all examined tissues and organs with the maximum expression levels at lignified regions in rice roots. Salt stress upregulates the expression of OsDIR55 gene in an abscisic acid (ABA)‐dependent manner. Loss‐function and overexpression of OsDIR55 compromised and improved the development of CS and root diffusion barrier, manifested with the decreased and increased width of CS, respectively, and ultimately affected the permeability of the apoplastic diffusion barrier in roots. OsDIR55 deficiency resulted in Na+ accumulation, ionic imbalance, and growth arrest, whereas overexpression of OsDIR55 enhances salinity tolerance and provides an overall benefit to plant growth and yield potential. Collectively, we propose that OsDIR55 is crucial for ions balance control and salt stress tolerance through regulating lignification‐mediated root barrier modifications in rice. Significance Statement: Collectively, we propose that OsDIR55 is crucial for ions balance control and salt stress tolerance through regulating lignification‐mediated root barrier modifications in rice. [ABSTRACT FROM AUTHOR]

The structures, mechanical properties and electronic structures of M metals (M=Ti, V, Cr, Mn and Fe) doped β-Si3N4 were investigated by First-principles calculations within CASTEP. The calculated lattice parameters of β-Si3N4 were consistent with previous date. The cohesive energy and formation enthalpy show that initial β-Si3N4 has the highest structural stability. The calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli of β-Si3N4 are slightly reduced by M doping. Based on Poisson's and Pugh's ratio, β-Si3N4 is a ductile material and the toughness of β-Si3N4 increases with M doping, and Fe doping exhibited the best toughness. The results of density of states, charge distributions and overlapping populations indicate that β-Si3N4 has the strong covalent and ionic bond strength between N and Si. [ABSTRACT FROM AUTHOR]

Traditional epoxy resins are made from non‐renewable fossil resources, which are difficult to reprocess and recycle, and their flammability makes them unsafe during use. In this experiment, an epoxy resin containing Schiff base (TA‐VAN‐EP) was synthesized successfully with biomass‐derived raw materials. This new material not only had favorable mechanical properties but also had good flame retardancy and degradation properties. The chemical structure of TA‐VAN‐EP was characterized by Fourier transform infrared (FTIR) spectroscopy and 1H nuclear magnetic resonance (NMR) spectroscopy. Its mechanical properties, thermal stability, flame‐retardant properties, and other properties were tested. The results showed that, compared with the pure epoxy resin (EP), the mechanical properties of TA‐VAN‐EP were significantly improved, and the glass transition temperature (Tg) was increased from 152°C to 190°C. Additionally, TA‐VAN‐EP reached a V‐1 rating during the UL‐94 test, and the limited oxygen index (LOI) value increased from 24.7% to 28.4%. Also, the total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) decreased extremely. Moreover, TA‐VAN‐EP demonstrated good degradation performance under acidic conditions. In conclusion, this work provided a new idea for the production of bio‐based flame‐retardant epoxy resin with promising degradable abilities and mechanical properties. [ABSTRACT FROM AUTHOR]