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The purpose of this study is to improve the mechanical properties of PBAT. Polybutylene adipate terephthalate (PBAT) has excellent biodegradability, which has been widely used in various fields, such as biomedical supplies, plastic packaging materials, industrial composting and daily sanitary consumables. However, the application of PBAT is limited by its high production costs and poor mechanical property. In this study, the glass fiber (GF)/PBAT composites were prepared, and the effect of GF and the modifiers on the structure, mechanical properties and shape memory properties of the composites were investigated.

In this work, GF, 3-aminopropyltriethoxysilane (KH550) and chain extender ADR 4370 were selected as reinforcement, GF and chain extender, respectively. The GF/PBAT, KH550-modified GF/PBAT and ADR-modified GF/PBAT composites were prepared by melt blending, extrusion granulation and hot pressing.

The study showed that the fracture strength and elongation at break of PBAT decreased with the increasing of GF, and the decline is controlled after addition of KH550 and ADR 3470. When the GF content was low (such as 5 wt% and 10 wt%), KH550 significantly improved the mechanical properties of the composites. When the GF content was high (such as 20 wt% and 25 wt%), the mechanical properties of the composites were obviously improved by addition of ADR 3470. In addition, the shape memory fixity ratios (R_f) and shape memory recovery ratios (R_r) of the composites increased and decreased with increase of GF content, the prestrain and tensile temperature, respectively. Furthermore, the Rf of the KH550 modified GF/PBAT composites were the lowest, the Rr were the highest than that of the ADR modified GF/PBAT composites and the untreated GF/PBAT composites.

GF/PBAT composites exhibited good mechanical properties and low production costs. The research can help promote the widespread use of PBAT and alleviate the situation of serious plastic pollution.

A novel biodegradable GF/PBAT composite was developed by chain extender ADR 4370, incorporating environmentally friendly GF with excellent mechanical properties into PBAT.

The purpose of this study is to improve the mechanical properties, thermal insulation properties and flame retardant properties of polyethylene terephthalate (PET), the organic montmorillonite (OMMT)/SiO₂ aerogel/PET composites and fibers were prepared, and the effects of the OMMT/SiO₂ aerogel on the structure, thermal conductivity and flame retardance of the OMMT/SiO₂ aerogel/PET composites and their fibers were systematically investigated.

The OMMT/SiO₂ aerogel/PET composites and fibers were prepared by in-situ polymerization and melt spinning using SiO₂ aerogel as thermal insulation filler and OMMT (DK2) as comodified filler.

The experimental results showed that OMMT improved the crystallization properties of PET. Compared with the crystallinity of SiO₂ aerogel/PET composites (34.8%), SiO₂ aerogel/PET composites and their fibers reached 45.1% and 49.2%, respectively. The breaking strength of the OMMT/SiO₂ aerogel/PET composite fibers were gradually increased with the OMMT content. When the content of OMMT was 0.8 wt.%, the fracture strength of the composite fibers reached 4.40 cN/dtex, which was 54% higher than that of the SiO₂ aerogel/PET fiber. In addition, the thermal insulation properties of the composites and their fibers were improved by addition of fillers, and at the same time reached the flame retardant level. The thermal conductivity of the 0.8 wt.% OMMT/SiO₂ aerogel/PET composites was 101.78 mW/(m·K), which was 49.3% and 58.8% lower than that of the SiO₂ aerogel/PET composites and the pure PET, respectively. The thermal conductivity of the fiber fabrics woven from the 0.8 wt.% OMMT/SiO₂ aerogel/PET composites was 28.18 mW/(m·K), which was 29.0% and 44.6% lower than that of the SiO₂ aerogel/PET composite fiber fabrics and PET fiber fabrics. The flame retardancy of the composites was improved, with an limiting oxygen index value of 29.2% for the 0.8 wt.% OMMT/SiO₂ aerogel/PET composites, which was 4.1% higher compared to the SiO₂ aerogel/PET composites, and achieved the flame retardant level.

The SiO₂ aerogel/PET composites and their fibers have good mechanical properties, flame retardant properties and thermal insulation properties, exhibited good potential for application in the field of thermal insulation, such as warm clothing. Nowadays, as the energy crisis is becoming more and more serious, it is very important to improve the thermal insulation properties of PET to reduce energy losses and mitigate the energy crisis.

In this study, PET based composites and their fibers with excellent mechanical properties, thermal insulation properties and flame retardant property were obtained by using three-dimensional network porous silica aerogel with low density and low thermal conductivity as the thermal insulation functional filler and two-dimensional layered OMMT as the synergetic modified filler.

Crystallization kinetics is a key factor that controls the crystallization process of polymers and influences the crystallinity and morphology of polymers. This study aims to explore the effects of functional filler SiO₂ aerogel and co-modified filler organic montmorillonite (OMMT) on the crystallization process of polyester polyethylene terephthalate (PET). In this study, the nonisothermal crystallization kinetics of OMMT/SiO₂ aerogel/PET composites were studied by Jeziorny method.

The catalyst (Sb₂O₃), OMMT and SiO₂ aerogel were uniformly dispersed in ethylene glycol (EG). Then, the mixture and terephthalic acid (PTA) were put into a semicontinuous polyester synthesis reactor, and the SiO₂ aerogel/PET composites were prepared by esterification and polycondensation.

Non-isothermal kinetic results showed that the high cooling rate hindered the movement of the molecular chain of the composites and made the crystallization peak move toward the low-temperature direction. With the increase of crystallization temperature (T_c), the melt crystallization rate decreases, but the cold crystallization rate increases. The introduction of OMMT and SiO₂ aerogel condensation affected the nucleation and growth mode of crystals, lengthened the time with a relative crystallinity of 50% (t_1/2) and decreased the crystallization rate. OMMT improved the crystallinity and Avrami index of the composites.

Effects of thermal insulation functional filler SiO₂ aerogel and co-modified filler OMMT on the crystallization process of PET were studied by non-isothermal crystallization kinetics, and the effects of SiO₂ aerogel and OMMT on the nucleation mechanism of PET were clarified, which provided a theoretical reference for the preparation and performance optimization of PET matrix composites.

In this study, the OMMT/SiO₂ aerogel/PET composites were prepared by in-situ polymerization, the crystallinity of PET matrix composites was improved, and the effects of OMMT and SiO₂ aerogel on the crystallization process of PET were clarified.

In light of the burgeoning interest in the Metaverse within educational contexts, this study provides a comprehensive review to address the knowledge gap prevalent among K-12 and higher education teachers and educators. The increasing integration of the Metaverse into classroom settings necessitates a systematic exploration of its impact on subject-specific pedagogy, assessment methods, research methodologies and overall learning outcomes.

The research design involves a systematic review of 34 selected studies published between 2009 and 2023. The inclusion criteria prioritize investigations into Metaverse applications in classroom teaching, with a focus on subject disciplines, pedagogical approaches, measurement metrics and research methodologies. The selected studies undergo a detailed analysis and synthesis to extract meaningful patterns and trends.

The analysis reveals a predominant concentration on higher education, encompassing both science, technology, engineering, and mathematics (STEM) and non-STEM disciplines. However, few studies adopt comprehensive experimental designs. This suggests a gap in the methodological rigor of current research on Metaverse integration in education. While the Metaverse's impact on higher education is evident, the study underscores the need for more robust experimental designs and comprehensive research methodologies.

The limited exploration of students' experiences with the Metaverse in educational settings highlights a nascent research area that warrants further investigation. Future research should prioritize measuring students' perceptions and performance through indicators such as test grades to enhance our understanding of the Metaverse's efficacy in educational contexts.

The study aims to offer insights into the current state of Metaverse integration in education and identify areas for further research and development.

This paper aims to prepare an oil-impregnated porous polytetrafluoroethylene (PTFE) composite with advanced tribological properties using citric acid as a novel pore-forming agent.

Citric acid (CA) was used to form pores in PTFE, and then oil-impregnated PTFE composites were prepared. The pore-forming efficiency of CA was evaluated. The possible mechanism of lubrication was proposed according to the tribological properties.

The results show CA is an efficient pore-forming agent and completely removed, and the porosity of the PTFE increases with the increase of the CA content. The oil-impregnated porous PTFE exhibits an excellent tribological performance, an increased wear resistance of 77.29% was realized in comparison with neat PTFE.

This study enhances understanding of the lubrication mechanism of oil-impregnated porous polymers and guides for their tribological applications.

Accurately judging the quality of marine economic development is the premise of grasping the level and status of marine economic development. In order to scientifically evaluate the development quality of regional marine economy, the purpose of this paper is to select the marine area of Qingdao as the research object, and construct a marine economic development quality evaluation index system with 16 indicators.

The raw data is normalized by the range conversion method, and the weight of the index is determined by the information entropy model. Further, the grey relational analysis (GRA) method is used to evaluate the quality of marine economic development of Qingdao from 2012 to 2017.

The results show that the marine economic development capacity of Qingdao is with the generally increasing trend, the total marine economy is with on the rising trend, the marine storage and transportation capacity, and marine ecological environment are first decreased, and then increased. The utilization of marine resources is generally decreasing, and the comprehensive management of oceans varies with the changes of environment and economy. Therefore, in view of the development capacity of marine economy, the coordinated development of economy and environment should be carried out.

This paper uses the GRA to evaluate the quality of marine economic development and provides a reference for the development of marine economy in Qingdao.

The state space method (SSM) is good at analyzing the interfacial physical quantities in laminated materials, while it has difficulty in calculating the mechanical quantities of interior points, which can be easily evaluated by the boundary element method (BEM). However, the material has to be divided into many subdomains when the traditional BEM is applied to analyze the functionally graded material (FGM), so that the computational amount will be increased enormously. This study aims to couple these two methods to strengthen their advantages and overcome their disadvantages.

Herein, a state space BEM in which the SSM is coupled by the BEM is proposed to analyze the elasticity of FGMs, where one BEM domain is set and the others belong to SSM domains. The discretized elements occur only on the boundary of the BEM domain and at the interfaces between different SSM domains. In SSM domains, the horizontal interfaces of FGMs are discretized by linear elements and the variables along the vertical direction are yielded by the precise integration method.

The accuracy of the proposed method is verified by comparing the present results with the ones from the finite element method (FEM). It is found that the present method can provide accurate displacements and stresses in the FGMs by fewer freedom degrees in comparison with the FEM. In addition, the present method can provide continuous interfacial stresses at the interfaces between different material domains, while the interfacial stresses by the FEM are discontinuous.

The system equations of the state space BEM are built by combining the boundary integral equation with the state equations according to the continuity conditions at the interfaces. The mechanical parameters of any inner point can be evaluated by the boundary integral equation after the unknowns on the boundaries and interfaces are determined by the system equation.

China has a new rural revitalization strategy to stimulate rural transformation through modernizing rural areas and resolving their social contradictions. While social capital is recognized as an important element to rural revitalization and entrepreneurship, research into the role of psychological capital is less developed. Therefore, this paper assesses the impact of both social and psychological capital on entrepreneurial performance of Chinese new-generation rural migrant entrepreneurs (NGRMEs) who have returned to their homes to develop businesses as part of the rural revitalization revolution.

Based on a survey, data were collected from 525 NGRMEs in Shaanxi province. This paper uses factor analysis to determine variables for a multiple linear regression model to investigate the impacts of dimensions of both social capital and psychological capital on NGRMEs’ entrepreneurial performance.

Through the factor analysis, social capital of these entrepreneurs consists of five dimensions (reputation, participation, networks, trust and support), psychological capital has three dimensions (innovation and risk-taking, self-efficacy and entrepreneurial happiness) and entrepreneurial performance contains four dimensions (financial, customer, learning and growth, and internal business process). Furthermore, the multiple linear regression model empirically verifies that both social capital and psychological capital significantly influence and positively correlate with NGRMEs' entrepreneurial performance.

This study shows the importance of how a mixture of interrelated social and psychological dimensions influence entrepreneurial performance that may contribute to the success of the Chinese rural revitalization strategy. This has serious implications when attempting to improve the lives of over 100 million rural Chinese citizens.

This paper aims to first analyze the reasons of a brick-wooden building tilts in Yunnan province in China. Then, a jacking method which combines the stress release methods and the excavation of stress release trench were put forward.

This method uses the anchor static pile to guarantee the safety of the building in the process of rectifying.

The practice showed that the inclination rate of the building was stable in the process of jacking, which proved the efficiency of the proposed method.

It has a great value for similar rectification projects, and for the protection of cultural heritage and ancient buildings have a positive effect.

There is a pressing need for research on the difference in entrepreneurial performance influenced by the integration of migrant workers’ psychological capital and entrepreneurial opportunity identification. In addition, there is limited research on the association of entrepreneurial performance with different dimensions of psychological capital and how these dimensions affect the entrepreneurial performance of migrant workers. This research will partially address this gap in knowledge by assessing the influence of psychological capital and entrepreneurial opportunity identification on the entrepreneurial performance of migrant workers in China.

This paper conducts a theoretical analysis of psychological capital, entrepreneurial opportunity identification and entrepreneurial performance and proposes a theoretical model of entrepreneurial opportunity identification acting as the intermediary role between psychological capital and the entrepreneurial performance of migrant workers. Based on the data collected from 899 rural households in Shaanxi Province, a structural equation model and a bootstrap method are used to verify the association between psychological capital, entrepreneurial opportunity identification and entrepreneurial performance.

Both entrepreneurial opportunity identification and psychological capital are conducive to the improvement of entrepreneurial performance. However, the entrepreneurial opportunity identification is found to exert a more significant impact on the entrepreneurial performance of migrant workers than psychological capital does. Findings have also revealed that the intermediary role of entrepreneurial opportunity identification is more prominent in the relationship between adventure and innovation and the entrepreneurial performance of migrant workers than that of self-confidence and optimism and entrepreneurial performance of migrant workers.

Based on the results of empirical analysis, the paper proposes corresponding policy recommendations for guiding migrant workers to capitalize on their psychological capital, identify entrepreneurial opportunities, weigh up entrepreneurial risks and ultimately improve their entrepreneurial performance.