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BackgroundNeutral beam injection heating is a very effective auxiliary heating method in magnetic confinement fusion experiment. The built 5 MW neutral beam injection plays an important role in the H-mode operation with 1 MA plasma current of HL-3 tokamak. In order to achieve the H-mode operation with 2.5 MA, three neutral beam injection heating systems will be constructed with a total heating power of 20 MW.PurposeThis study aims to investigate the transmission efficiency of 7 MW neutral beam injector designed for HL-3 tokamak.MethodsThe beam transmission efficiency was studied from two aspects of neutralization efficiency and power deposition. The initial target thickness of the neutralizer under two beam parameters was analyzed based on Monte Carlo method. The optimal neutralization efficiency was achieved by adding neutralizer gas supply, and the target thickness required for the optimal neutralization efficiency was given. Finally, power deposition method was employed to analyze the transmission performance of the two neutral beams with different parameters at different beam divergence angles.ResultsThe results show that the optimal neutralizer efficiency is achieved when the neutralizer gas supply is 0.6 Pa∙m3∙s-1 and 1.1 Pa∙m3∙s-1, respectively. The neutral beam power obtained under two beam parameters with a divergence angle of 1.2° is 7.2 MW and 6.8 MW, respectively, and the corresponding transmission efficiency is 0.4 and 0.35, respectively.ConclusionsThe new neutral beam injector of HL-3 tokamak will be built according to the design of this study, with optimized parameter of 100 kV/45 A, while still retaining the ability to deliver a 120 keV deuterium beam.

This research addresses the critical issue of major fishing vessel accidents, which traditionally suffer from a lack of focused analysis due to their rarity and the subjective nature of their classification. We propose an innovative methodology of Peaks Over Threshold to overcome subjectivity in accident classification. This approach ensures a more representative and accurate analysis of major accidents, distinguishing them from more common, less severe incidents. Employing a Bayesian network model, we further explore the most influential factors contributing to these major accidents. The key innovation lies in our novel approach to data handling and analysis, enabling us to uncover hidden patterns and causal relationships that traditional methods often overlook. The results show that the approach proposed in this study can effectively capture the key factors of major fishing vessel accidents. This study identifies accident type, vessel-related factors, and accident location as the key influential factors leading to major accidents. The findings from our research are intended to inform sustainable fisheries management practices, promoting interventions that aim to decrease the occurrence and impact of severe maritime accidents while balancing economic, safety, and sustainable development considerations. [ABSTRACT FROM AUTHOR]

With the improvement of China’s international status, the international dissemination of Chinese red culture is facing some big problems such as inaccurate language expression, inadequate cultural connotation, and insufficient communication paths, which has seriously limited the nation’s foreign discourse ability. Therefore, in order to bring China’s excellent culture and red tourism brands to the world and meet the strategic requirement of high-quality development in China, it puts forward some detailed and feasible strategies to improve the ability of sharing Chinese stories better by strengthening the language translation ability, to ensure the inherent needs of the cultural field by shortening cultural differences, and to expand publicity channels by establishing multi-lateral cooperation mechanism.

For the design of sustainable buildings, it is crucial with accurate methods to evaluate how alternative constructions will influence thermal comfort, as well as energy efficiency. This study introduces a model to investigate how the use of phase change materials (PCM)in building envelopes can influence the temperature stratification, which also influences the indoor thermal comfort. PCM is characterized by large latent heat in the melting/solidifying process during phase transition. Applications with PCM have been recognized as possible alternatives in building envelopes to improve thermal comfort as well as energy efficiency. The selection of the properties of the PCM, as well as how and where the PCM was installed in the building envelope, are crucial factors to be considered before application in practice. In this study, a simplified experimental set-up including a hot-box was used. The PCM material Climsel28 with different layers thicknesses was installed in the sidewall of a hot-box. Extruded polystyrene (XPS) foam boards were used as wall insulation material in the study. XPS was installed as a reference case and in different layer combinations with the PCM. The sequence of the XPS and PCM was varied. Temperature and heat flux were measured in different positions of the hot-box and on the tested walls. A 3D COMSOL model was developed to study the thermal performance of the system. The model was validated in the study using the collected experimental data. The results indicated that the developed COMSOL model can reasonably predict the performance of the system, both with and without the incorporation of PCM. Additionally, the measured temperature stratification were theoretically validated by the COMSOL model. The study gives indicative guidance of how PCMs can be installed in building constructions elements to reduce temperature peak loads and thus also contributing to an improvement of the indoor thermal comfort.