Guidance For Design Research Articles

Influence of surface chemistry on Li nucleation energetics on graphene-based surfaces.

Lithium metal is a promising high-capacity anode material for solid-state batteries, but it typically suffers from poor cyclability. Carbon scaffold hosts have the potential to improve this performance due to their high electronic conductivity and large surface area, which facilitates lithium-ion adsorption and desorption. Scaffold surface chemistry is known to significantly influence performance outcomes, but the details of these interactions are not fully understood. This study employs first-principles simulations to explore lithium transport and nucleation on graphene anodes with various surface chemistries. Using enhanced sampling techniques, abinitio molecular dynamics, and density functional theory calculations, we find that although surface chemistry has a minimal impact on lithium interfacial transport, it influences surface nucleation significantly. Both heteroatom dopants and intrinsic defects lower the nucleation barrier, creating a more favorable environment for lithium nucleation compared to pristine graphene. In addition, our results reveal a complex interplay between surface lithium concentration, lithium transport, and nucleation kinetics. These findings highlight the potential of surface modifications to precisely control nucleation processes on carbon-based anodes and provide design guidance for reducing dendrite formation and improving the cycle life of solid-state batteries.

A Study on the Relationship Between the Pore Characteristics of High-Performance Self-Compacting Concrete (HPSCC) Based on Fractal Theory and the Function of the Water–Binder Ratio (W/C)

The mechanical properties of High-Performance Self-Compacting Concrete (HPSCC) are strongly influenced by its pore structure, but the impact of varying water–binder ratios (W/C) on this relationship remains unclear. To address this, the present study investigates HPSCC with W/C ratios ranging from 0.19 to 0.23, aiming to elucidate the connection between pore structure, fractal characteristics, and mechanical performance. Through a combination of compressive strength testing, low-temperature nitrogen adsorption, and Scanning Electron Microscopy (SEM) observations, this study reveals key insights. First, compressive strength initially increases with a decreasing W/C ratio but plateaus beyond W/C = 0.21, identifying an optimal range for balancing strength and workability. Second, the pore structure of HPSCC is characterized by cylindrical, ink-bottle, and planar interstitial pores, with significant fractal characteristics. Notably, the fractal dimension decreases as the W/C ratio increases, indicating reduced pore complexity and improved homogeneity. Finally, a strong linear correlation (R2 > 0.9) between the W/C ratio, fractal dimension, and compressive strength provides a predictive tool for assessing HPSCC performance. This study concludes that the internal pore structure is a critical determinant of HPSCC strength, and the identified optimal W/C ratio range offers guidance for mixture designs. Additionally, fractal dimension analysis emerges as a novel method to evaluate HPSCC’s microstructural quality, enabling predictions of long-term performance and durability. These findings contribute to the scientific basis for designing high-performance concrete materials with improved mechanical properties and durability.

Enhancing Long-Term Viability of Energy Pile with Heat Sink Systems in Tropical Monsoon Climates: Implementation Strategies and Performance Analysis

Energy piles, a form of ground-source heat pump system integrated into building foundations, show great potential for reducing building energy consumption associated with fossil fuels. While it excels in climates where cooling demand matches heating, its effectiveness faces challenges in tropical monsoon regions characterized by hot summers and cool winters. In such climates, cooling demand dominates, leading to significant thermal accumulation over time, which diminishes the long-term viability of energy pile systems. This study focuses on the long-term thermal behavior analysis of an energy pile system installed in a representative office building. Our approach begins with an examination of short-term behavior, followed by the creation of a simplified model. Using this model, we analyze the long-term behavior of different systems, including the standard energy pile and combinations with various solutions: natural groundwater flow and synthetic heat sink systems. Key outcomes are evaluated based on entering water temperature (EWT), soil temperature, and energy efficiency ratio (EER), while also comparing energy savings with conventional air conditioning systems. Major findings include: (1) Standard energy pile systems without any mitigation measures achieve only a 15.3% energy savings initially and may cease functioning after approximately 10 years, (2) Energy pile systems using specific solutions can achieve a maximum saving ratio of 50%, typically ranging from 30% to 45%, while maintaining stability over the designated lifespan, (3) Higher EER and saving ratios correlate with increased groundwater flow and larger heat sink systems, however, the relationship is nonlinear, emphasizing the need for tailored design under varying geology and climate conditions. This study provides essential insights into energy pile systems design and practical guidance, along with expected energy savings in tropical monsoon climates for future application.

VISUAL IMAGE DESIGN OF JINGDEZHEN PORCELAIN BRAND UNDER THE PERSPECTIVE OF MEME

Starting from the perspective of Meme Theory, this study explores the ideas of Jingdezhen porcelain brand design in order to break through the limitations of traditional porcelain development, realize cultural inheritance and innovation, and promote the sustainable development of the porcelain industry. Literature survey, field research and case study method are used to comprehensively analyze the current situation of visual image design of Jingdezhen porcelain brand, and propose brand design strategies in combination with Meme Theory. The study finds that Meme Theory has significant validity in cultural communication, plays a central role in Jingdezhen porcelain culture, and provides new ideas for brand visual image design. The study provides support for the inheritance and innovation of Jingdezhen porcelain culture, provides theoretical and practical references for the protection and development of regional culture, enriches the scope of application of Meme Theory, and provides specific guidance for porcelain product design, emphasizes the significance of cultural modality for the development of local cultural industry, and has far-reaching value for promoting the inheritance and innovation of Jingdezhen porcelain culture.

Development of a New ‘Engineering English for Intercultural Communication’ Online Course to Prepare New Engineers for Working in Intercultural Workplace Settings

This study aimed to develop a tailor-made online course called “Engineering English for Intercultural Communication (EEIC)” for undergraduate engineering students based on the self-report on English language proficiency, intercultural communication competence (ICC) as well as needs of a diverse set of stakeholders in the engineering professions and education. It comprises two phases: (1) analyzing the data from the stakeholders, and (2) designing and developing a course. In the first phase, a mixed-methods approach was adopted. A questionnaire was employed for a self-report on English language proficiency and problems in language use, as well as the ICC of 108 Thai engineering students at an autonomous university in Thailand and 22 Thai engineering professionals working in international companies. Then, semi-structured interviews on the necessity of engineering English and ICC for novice engineers were conducted with 16 engineering course lecturers. The second phase involves the design and development of the EEIC course. The ADDIE model was adopted and the findings from the analysis of the data collected in the first phase were used to guide the design and develop such a course with four units, each with a different focus, specifically. This study contributes to the ELT field by showcasing a course design process to meet the needs of a set of diverse stakeholders. Specifically, the course was developed based on real-life information obtained from both educational and professional contexts analyzed to provide guidance for the course design and development.

Social Innovation Perspective on Regional Design and Sustainable Development Research

In today’s world, the development of regional industries and cross-regional cultural integration have brought about environmental damage and cultural erosion. However, there are many shortcomings in the research and countermeasures for the problem, especially in China. The greater participation of the whole society in innovative regional design has a huge impact on the sustainable development of the region. This research aims to provide a more comprehensive understanding framework for regional design and strategic guidance for future research directions and practical paths. We adopted the methods of a literature review and a case analysis to discuss the importance of social cooperation in social innovation from the perspectives of cultural inheritance, community participation, industrial upgrading, and brand building. Based on Professor Kiyoshi Miyazaki’s “Human Culture Land Production Landscape” resource integration model, combined with specific regional goals, five major design domains have been constructed to address five issues. In specific regional design practices, participatory design, value co-creation, and resource integration design methods have been applied. Research has found that these theoretical and practical paths have achieved good results and played a positive role in promoting the Sustainable Development Goals (SDG9 and SDG11).

Communicating with Stakeholders to Identify High-Impact Research Directions for Non-Targeted Analysis.

Non-targeted analysis (NTA) using high-resolution mass spectrometry without defined chemical targets has the potential to expand and improve chemical monitoring in many fields. Despite rapid advancements within the research community, NTA methods and data remain underutilized by many potential beneficiaries. To better understand barriers toward widespread adoption, the Best Practices for Non-Targeted Analysis (BP4NTA) working group conducted focus group meetings and follow-up surveys with scientists (n = 61) from various sectors (e.g., drinking water utilities, epidemiologists, n = 9) where NTA is expected to provide future value. Meeting participants included producers and end-users of NTA data with a wide range of familiarity with NTA methods and outputs. Discussions focused on identifying specific barriers that limit adoption and on setting NTA product development priorities. Stated priorities fell into four major categories: 1) education and training materials; 2) QA/QC frameworks and study design guidance; 3) accessible compound databases and libraries; and 4) NTA data linkages with chemical fate and toxicity information. Based on participant feedback, this manuscript proposes research directions, such as standardization of training materials, that BP4NTA and other institutions can pursue to expand NTA use in various application scenarios and decision contexts.

Numerical Design and Optimization of High Performance Langasite and Hetero-Acoustic Layer-Based Surface Acoustic Wave Device

La3Ga5SiO14 (langasite, LGS)-based surface acoustic wave (SAW) devices are widely used for industrial health monitoring in harsh high-temperature environments. However, a conventional LGS-based SAW structure has a low quality factor (Q) due to its spurious resonant peaks. A hetero-acoustic layer (HAL)-based structure can effectively enhance the Q factor and the figure of merit (FOM) of SAWs due to its better energy confinement of SAWs. In this work, a HAL-based structure is proposed to achieve a high FOM and high-temperature resistance at the same time. Based on the finite element method (FEM) and coupling-of-model (COM) combined simulation, a systematic numerical investigation was conducted to find the optimal materials and structural parameters considering the viability of an actual fabricating process. After optimizing the layer number, an intermediate-layer material choice and structural parameters, Pt/(0°, 138.5°, 27°) LGS/YX-LGS/SiC HAL structure were chosen. The proposed structure achieves a Q factor and FOM improvement of more than 5 and 2.6 times higher than those of conventional SAW structures, which is important for the development of high temperature SAW sensors. These findings pave a viable method for improving the Q factor and FOM of LGS-based SAW and can provide material and device structural design guidance for fabrication and high-temperature applications in the future.

Density Functional Theory Study on Reconstruction and Reversible Transformation Processes of the ZZ57 Edge Structure in Carbon Materials: Effect of Na, K, and Ca.

The edge structures of carbonaceous materials exhibit temperature-dependent behavior on the atomic scale, with variations in the relative ratios of zigzag, reconstructed 5-7 zigzag (ZZ57), and armchair edges observed at different temperatures. Nevertheless, the mechanisms underlying the interconversion of these edge structures and the influence of the surrounding metals remain unclear. This study investigates the reconstruction and reversible transformation processes of ZZ57 edge structures in carbon materials and examines the effects of different metal atoms (Na, K, and Ca) by using density functional theory. The simplified Z57 and A57 models are selected to simulate the microscopic reaction pathways at the isolated system level. Wave function analysis is conducted to determine the physical and chemical characteristics of ZZ57 edge structures and to predict the optimal adsorption positions of the metal atoms. Results indicate that the ZZ57 edge structure reconstruction and reversible transformation are exothermic reactions that proceed favorably in the forward direction. Analysis of the ten-membered ring in the transition state structure shows that the average bond order of the C-C bond is lower than that in the benzene ring system. Thermodynamic analysis shows that Na, K, and Ca atoms reduce the chemical equilibrium constant, thereby hindering the progress of the reactions. These findings not only provide specific theoretical insights into the transformation of the ZZ57 edge structure but also offer guidance for the precise design of carbon edges and the development of practical carbon materials.

Seismic Performance Evaluation of Reinforced Concrete Frame–Shear Wall Structural Systems in Thermal Power Plants

The seismic performance of an electric power system is crucial for maintaining the functionality of urban communities following an earthquake. In thermal power plants, the RC frame–shear wall structure plays a key role in providing seismic resistance to the main building’s longitudinal structural system. This study presents the results of a series of pseudo-dynamic tests on a two-span, four-story frame–shear wall model with a scale of 1/8. The prototype structure was a seven-story, seven-bay longitudinal RC frame–shear wall from the main workshop of a large thermal power plant. The cracking process, yielding sequence, hysteresis curves, and skeleton curve were obtained. Based on the test results, the energy dissipation, equivalent viscous damping coefficient, ductility and deformation, stiffness degradation, dynamic response, and displacement response were analyzed. The results showed that the RC frame–shear wall structure exhibits a high energy dissipation capacity and excellent seismic performance, and the shear wall significantly influences the structural bearing capacity and deformation performance. These findings offer valuable guidance for the seismic design of RC frame–shear wall structures in high-rise and large factory buildings. As the shear wall absorbs the majority of seismic forces and minimizes the concentration of plastic deformation, strengthening critical weak areas—such as increasing the horizontal distribution of rebars or improving the concrete strength at the shear wall base—can enhance overall structural performance and seismic resilience in industrial buildings subject to seismic loading.

3D-QSAR, design, molecular docking and dynamics simulation studies of novel 6-hydroxybenzothiazole-2-carboxamides as potentially potent and selective monoamine oxidase B inhibitors

Background6-hydroxybenzothiazole-2-carboxamide is a novel, potent and specific inhibitor of monoamine oxidase B (MAO-B), which can be used to study the molecular structure and develop new neuroprotective strategies.ObjectiveThe aim of this study was to create an effective predictive model from 6-hydroxybenzothiazole-2-carboxamide derivatives to provide a reliable predictive basis for the development of neuroprotective MAO-B inhibitors for the treatment of neurodegenerative diseases.MethodsFirst, the compounds were constructed and optimized using ChemDraw and Sybyl-X software. Subsequently, QSAR modeling was performed using the COMSIA method in Sybyl-X to predict the IC50 values of a set of novel 6-hydroxybenzothiazole-2-carboxamide derivatives. The ten most promising compounds were screened based on the IC50 values and tested for molecular docking. Finally, the binding stability and dynamic behavior of these compounds with MAO-B receptors were analyzed by molecular dynamics simulation (MD).ResultsThe 3D-QSAR model showed good predictive ability, with a q2 value of 0.569, r2 value of 0.915, SEE of 0.109 and F value of 52.714 for the COMSIA model. Based on the model, we designed a series of novel 6-HBC derivatives and predicted their IC50 values by the QSAR model. Among them, compound 31.j3 exhibited the highest predicted IC50 value and obtained the highest score in the molecular docking test. MD simulation results showed that compound 31.j3 was stable in binding to the MAO-B receptor, and the RMSD values fluctuated between 1.0 and 2.0 Å, indicating its conformational stability. In addition, energy decomposition analysis revealed the contribution of key amino acid residues to the binding energy, especially Van der Waals interactions and electrostatic interactions play an important role in stabilizing the complex.ConclusionIn this study, the potential of 6-hydroxybenzothiazole-2-carboxamide derivatives as MAO-B inhibitors was systematically investigated by 3D-QSAR, molecular docking and MD simulations. The successfully designed compound 31.j3 not only demonstrated efficient inhibitory activity, but also verified its stable binding to MAO-B receptor by MD simulation, which provides strong support for the development of novel therapeutic drugs for neurodegenerative diseases. These findings provide important theoretical basis and practical guidance for future drug design and experimental validation.

Vehicle Collision Load Design Demands for Deck Overhangs with Parapet Railings

The majority of bridge rails used in the U.S.A. and Canada are solid concrete parapets. However, the design procedure included in the AASHTO LRFD Bridge Design Specifications (BDS) for deck overhangs supporting parapets has not been modified for nearly 50 years. The specifications currently recommend that the deck overhang moment demand is taken as the cantilever bending strength of the parapet at its base. This recommendation results in uneconomical deck designs if the parapet is overdesigned. In this research effort, which was performed under National Cooperative Highway Research Program Project 12-119, the distribution of vehicle impact loads through the parapet and overhang was characterized, new equations were proposed to calculate overhang design demands, and the effect of deck understrength on parapet capacity was quantified. To develop updated design guidance, physical testing of instrumented specimens was performed, and validated LS-DYNA models were used to evaluate a variety of in-service railing and overhang designs. Results indicated that deck moments from lateral vehicle impact loads can be reliably estimated by assuming they distribute at 45 degrees with downward travel through the parapet and at 60 degrees with inward travel through the overhang. These angles are used to calculate effective lengths at critical sections, and overhang design moments are calculated by dividing the total applied moment over these lengths. Distribution of tensile loads was found to be minimal. The overhang design guidance developed in this project, which is currently under review for adoption into the BDS, routinely results in more economical deck designs than the existing method.

Mechanism of stable lithium plating and stripping in a metal-interlayer-inserted anode-less solid-state lithium metal battery

To reliably operate anode-less solid-state Li metal batteries, wherein precipitated Li acts as the anode, stabilizing the interface between the solid electrolyte and electrode is crucial. The interface can be controlled by a metal interlayer on the electrolyte to form a Li alloy buffer that facilitates stable Li plating/stripping, thereby mitigating the loss of physical contact and preventing short circuits. However, the mechanism governing stable Li plating/stripping in the metal interlayer without degrading battery materials remains unclear owing to an incomplete understanding of the dynamic and complex electrochemical reactions in the solid state. Through multiple operando and post-mortem analyses of the Li deposition behavior in the morphology, chemistry and microstructure, a close correlation is found between the Li-metal alloying process with the microstructural evolution and electrochemical performance when Ag, Au, Zn, and Cu interlayers were adopted on the garnet-type solid electrolyte Li6.5La3Zr1.5Ta0.5O12. The Ag interlayer improved the interfacial stability enabled by Ag-dissolved Li, which inhibited dendritic growth, passing through the phase-separated Li-Ag alloy microstructure, while the other metals did not because of the Li plating at the Li-metal alloy/solid electrolyte interface. This work provides fundamental guidance for material selection and interface design, advancing the development of anode-less solid-state batteries.

Monolayer MoS2 with S vacancy defects doped with Group V non-metallic elements (N, P, As): a first-principles study.

This study systematically investigated the effects of single S-atom vacancy defects and composite defects (vacancy combined with doping) on the properties of MoS2 using density functional theory. The results revealed that N-doped S-vacancy MoS2 has the smallest composite defect formation energy, indicating its highest stability. Doping maintained the direct band gap characteristic, with shifts in the valence band top. The Fermi level slightly shifted down in N- and P-doped systems, with N-doped MoS2 showing a larger increase in valence band top energy. Doping also significantly altered the density of states at the Fermi level and weakened the dielectric properties of MoS2. The maximum dielectric peaks of doped systems appeared near 2.7 eV with reduced intensities and red-shifted energies. Optical properties were significantly changed, with decreased reflectance, narrower reflectance spectra, and blue-shifted absorption spectra. These findings suggest that introducing composite defects can effectively reduce the forbidden bandwidth of MoS2, enhancing electrical conductivity. This research provides theoretical guidance for novel material design and offers insights into composite defect behavior in other two-dimensional materials. The Materials-Studio CASTEP module was used to calculate density functional theory (DFT). A plane wave ultrasoft pseudopotential is used to optimize the crystal structure, and the generalized gradient approximation (GGA) in the form of Perdew-Burke-Ernzerhof (PBE) is used to characterize the exchange correlation energy. After the convergence test, the truncation energy and dot settings were finally selected to be 450 eV and 3 × 3 × 1, respectively, the convergence accuracy was set to 1.0e-5eV/atom, and the convergence criterion for the interatomic interaction force was 0.02 eV/Å. The parameters were all at or better than the accuracy settings. The vacuum layer between the layers wasset to 18 Å to avoid interactions caused by the periodic calculation method.

Critical Filling Height of Embankment over Soft Soil: A Three-Dimensional Upper-Bound Limit Analysis

This paper investigates the critical filling height of embankments over soft soil using three-dimensional (3D) upper-bound limit analysis based on a rotational log-spiral failure mechanism. Soft soils are characterized by low shear strength and high compressibility, making the accurate determination of critical filling height essential for evaluating embankment stability. Unlike conventional two-dimensional (2D) analyses, the proposed 3D method captures the true failure mechanism of embankments, providing more realistic and reliable results. The upper-bound analysis equations are derived using the principle of virtual work and solved efficiently through the genetic algorithm (GA), which avoids the limitations of traditional loop and random searching algorithms. The proposed solution is validated by comparing it with existing studies on slope stability and demonstrates higher accuracy and computational efficiency. Parametric studies are conducted to evaluate the influence of the depth–height ratio (the ratio of soft soil depth to embankment height) on the failure width of the embankment, the critical failure surface, and the critical filling height. Results show that the critical failure surface is tangential to the bottom of the soft soil layer and the critical filling height increases as the depth–height ratio decreases. The findings provide a set of critical filling heights calculated under various soft soil depths, strength parameters, and embankment geometries, offering practical guidance for embankment design.

Effects of Illuminance Level of Light Source on White Appearance of a Tablet Display

The appearance of white significantly impacts display image quality, requiring a neutral white point for optimal performance. This study explores how perceived whiteness changes under ambient illumination levels (150, 300, 600, and 1200 lx) and correlated color temperatures (3500 K and 6500 K). As a result, the adapted white points of light sources with different correlated color temperatures are similar at lower ambient illuminance levels. In comparison, their adaptation trends exhibit significant differences at higher illuminance levels. At 150 lx, adapted white points for 3500 K and 6500 K light sources shift toward higher color temperatures and converge. With increased illumination, the 3500 K white point shifts toward its light source, while the 6500 K white point shifts to a higher correlated color temperature. The neural network-based prediction model developed in this study accurately forecasts perceived whiteness across conditions, offering valuable design guidance for the display and lighting industries.

A Conceptual Framework for a Latest Information-Maintaining Method Using Retrieval-Augmented Generation and a Large Language Model in Smart Manufacturing: Theoretical Approach and Performance Analysis

In the modern manufacturing environment, the ability to collect and refine data in real time to deliver high-quality data is increasingly important in maintaining a competitive advantage and operational efficiency. This paper proposes a conceptual architectural framework for the continuous knowledge updating of Retrieval-Augmented Generation-Large Language Model-based systems in a smart factory environment. The proposed framework provides theoretical models and validation methodologies, laying the groundwork for future practical implementations. Existing Retrieval-Augmented Generation-Large Language Model systems rely on static knowledge bases that are not able to effectively reflect new information in a real-time, changing manufacturing environment. The proposed framework design uses a data stream processing layer, a data integration layer, and a continuous learning layer as core components; in particular, the knowledge integration layer provides a mechanism for the efficient processing of real-time data and continuous learning. This study is significant in that it presents a mathematical model and a systematic verification methodology that can quantitatively predict the performance and scalability of the proposed architecture, thus providing practical design guidance for the implementation of Retrieval-Augmented Generation-Large Language Model systems in smart factory environments. This paper is organized as follows: Materials and Methods provides a detailed description of the architecture and methodology. Theoretical Analysis and Discussion covers the theoretical analysis and discussion, including performance prediction models, validation methodologies, and their practical implications. Finally, Conclusions summarizes the research findings and outlines directions for future work.

Ascertaining the Environmental Advantages of Pavement Designs Incorporating Recycled Content through a Parametric and Probabilistic Approach.

Reclaimed asphalt pavement (RAP) is a widely used end-of-life (EoL) material in asphalt pavements to increase the material circularity. However, the performance loss due to using RAP in the asphalt binder layer often requires a thicker layer, leading to additional material usage, energy consumption, and transportation effort. In this study, we developed a parametric and probabilistic life cycle assessment (LCA) framework to robustly compare various pavement designs incorporating recycled materials. Our framework is built upon thermodynamic and physical principles to reveal the complex relationship among the parameters. Mechanistic-Empirical Pavement Design Guide (MEPDG) models and Highway Development Management (HDM4) models are integrated into the framework to estimate pavement roughness and vehicle fuel consumption during the use phase. The pedigree approach and Monte Carlo simulation are integrated into the framework to reflect data uncertainty at the parameter level. We applied the framework to evaluate 66 Flemish motorway segments, revealing that using RAP in the binder layer with increased thickness does not necessarily guarantee lower greenhouse gas (GHG) emissions for pavement construction. However, it may lead to lower GHG emissions due to fuel savings when considering the use phase, highlighting the vital role of the use phase in pavement LCA. Our global sensitivity analysis highlights several contributors (out of 87 parameters) to GHG emissions variance depending on the LCA scope: fuel consumption during the use phase, transport distances, mass of fine aggregate, and machine power and machine productivity during pavement construction. Reducing uncertainties in these parameters can decrease the variance by up to 60%, enhancing discernibility by up to 11%. In conclusion, our parametric and probabilistic LCA framework provides a nuanced understanding when comparing various pavement designs incorporating recycled content, enabling robust decision-making through improved data quality.

Effect of Temperature on Condensed State Structure and Conductivity Characteristics of Micron-Level Biaxially Oriented Polypropylene Films.

Polymer-based dielectric films are increasingly demanded for devices under high electric fields used in new energy vehicles, photovoltaic grid connections, oil and gas exploration, and aerospace. However, leakage current is one of the significant factors limiting the improvement of the insulation performance. This paper tested the leakage current and condensed state structure characteristics of biaxially oriented polypropylene (BOPP) films and obtained the nonlinear characteristics of leakage current of BOPP films in the range of 40-440 V/μm and 40-110 °C. The conduction mechanisms of BOPP films are hopping conductivity within 40-120 V/μm and the Poole-Frenkel effect within 120-440 V/μm, and the threshold electric field of the two kinds conduction mechanisms decreases from 120 to 80 V/μm above 70 °C. The in situ FTIR results indicate that the structure of the BOPP films including band structure, amorphous phase, and isotacticity indices changes above 70 °C, corresponding to the threshold electric field of both conductivity mechanisms gradually decreasing from 120 to 80 V/μm at 70 °C. This study can provide guidance for the optimization design to suppress the leakage current of BOPP and improve its insulation performance.

Research progress on thermal comfort evaluation in vehicle cab

In order to improve thermal comfort of vehicle cab, reduce driver fatigue and further improve work efficiency, researches on thermal comfort of vehicle cab are summarized. Research background of thermal comfort for vehicle cab is analyzed. And then related research progress on thermal environment in vehicle cab is studied from aspect of time and space, and thermal environment inside and outside vehicle are compared. Affecting factors of thermal comfort in vehicle cab are discussed in depth, which conclude thermophysical parameters, human physiological factors, clothing thermal resistance and other secondary factors. And thermal comfort evaluation indexes are analyzed in depth. Evaluation methods of thermal comfort in uniform environment are analyzed, related experimental research and theoretical analysis are summarized, and it also points out some problems in thermal comfort of vehicle at this stage, and also gives corresponding solutions. The future trend of thermal comfort of vehicle cab is predicted. Analysis results can provide theoretical guidance for optimization design of air conditioning supply parameters and structural parameters, and has significant meaning of improving thermal comfort of vehicle cab.