Zhenghua Rao

A multifunctional composite phase change material based on a low-melting-point molten salt was prepared by vacuum impregnation of the molten salt and expanded graphite into a three-dimensional nickel foam framework. Its structural, thermal, optical, and magnetic properties were characterized, and the photothermal, magnetothermal, and coupled heat-transfer behaviors were evaluated experimentally and numerically. MS/EG6/NF60 provided the best balance between heat-transfer enhancement and molten-salt loading, reaching a stored energy of 1435.04 J and a photothermal energy storage efficiency of 29.4% under 8-sun irradiation. Increasing the irradiation intensity from 6 to 10 sun raised the maximum temperature from 163.6 to 226.6 °C and shortened the phase change response time from approximately 1050 to 470 s, while the efficiency decreased from about 26% to 20% because of increased heat losses. Under pulsed magnetic excitation, the temperature of MS/EG6/NF60 increased from 85.5 to 153.8 °C within 15 s. The validated CT reconstructed model yielded an average magnetic flux density of 4.3275 mT, an electromagnetic heat generation density of 6.2445×10⁵ W/m³, and a total magnetothermal power of 5.6498 W. Under 6-sun irradiation, staged magnetic assistance reduced the time required to reach 150 °C from 975.50 to 454.36 s and increased the peak specific energy storage capacity from 131.1 to 161.4 J/g. The combined surface photothermal and internal magnetothermal heating accelerated thermal charging and improved temperature uniformity without continuous magnetic input.

Under China’s dual-carbon agenda and the accelerating green and digital transformation of the energy industry, higher education institutions face increasing pressure to prepare engineers for sustainable development. This article reports a longitudinal institutional case study of three energy-related undergraduate programs at Central South University, China. The core implementation period was 2018–2024; 2012 progression data were used as a descriptive pre-reform reference, and 2025 destination data provided a follow-up endpoint. The study reconstructs the author-developed model from curriculum documents, project and award records, graduate-destination statistics, employer-feedback summaries, textbook-adoption records, and dissemination records. It uses descriptive comparison and documentary triangulation; no control group or statistical significance tests were used. The Sustainability-Oriented Training Model for Energy Majors coordinates values and responsibility formation, science-education empowerment, and green and digitally enabled innovation through a task-driven full-cycle tutor system and four supporting mechanisms: value anchoring, knowledge iteration, a practice closed loop, and dynamic assessment. During the implementation period, the institutional records show higher postgraduate progression at the reported endpoints and favorable employment, employer-feedback, student-innovation, curriculum-renewal, and dissemination indicators. These outcomes are associated with the implementation period but do not establish causal effects or directly measure sustainability competencies. The case offers a context-dependent framework for sustainability-oriented reform in engineering education.

To address the heat dissipation demands of UAV lithium-ion battery modules under high-rate discharge and compact structural configurations, a flexible composite phase change film PW/SEBS/Fe3O4 was fabricated in this study. The composite film was prepared through physical blending followed by hot pressing, exhibiting self-supporting and bendable characteristics that enabled intimate conformity to the surface of cylindrical cells. Meanwhile, the incorporation of Fe3O4 fillers provided additional heat transfer pathways, thereby significantly enhancing the thermal conductivity of the material. A three-dimensional transient electrochemical–thermal coupled model of a 3s2p 18650 battery module was established in COMSOL and validated by constant-current discharge temperature-rise experiments. Parametric analysis showed that the matching between the PCM melting temperature and the late-stage heat generation peak of the battery is critical for effective peak temperature suppression, and a melting-point window of 40–45 °C is more advantageous under high-rate operating conditions. Increasing the thickness of the PCM layer can continuously reduce the peak temperature; however, the peak-shaving efficiency per unit volume decreases accordingly. Considering the 50 °C safety threshold together with the mass constraints of UAV applications, a recommended PCM thickness of approximately 2.6-3.0 mm is proposed. Three ring-encapsulation layouts with different connectivity levels (IRE, WRE, and SRE) were further compared based on the 3 mm PCM configuration. The results showed that increasing PCM connectivity improved material utilization and volumetric cooling efficiency with only a slight sacrifice in peak-temperature suppression, among which the SRE layout exhibited the best overall lightweight thermal management potential. This study provides useful guidance for the design of flexible composite phase change films for lightweight thermal management of UAV battery modules.