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Passenger thermal comfort in high-speed train (HST) carriages presents unique challenges due to factors such as extensive operational areas, longer travel durations, larger spaces, and higher passenger capacities. This study aims to propose a new prediction model to better understand and address thermal comfort in HST carriages. The proposed prediction model incorporates skin wettedness, vertical skin temperature difference (ΔTd), and skin temperature as parameters to predict the thermal sensation vote (TSV) of HST passengers. The experiments were conducted with 65 subjects, evenly distributed throughout the HST compartment. Thermal environmental conditions and physiological signals were measured to capture the subjects' thermal responses. The study also investigated regional and overall thermal sensations experienced by the subjects. Results revealed significant regional differences in skin temperature between upper and lower body parts. By analyzing data from 45 subjects, We analyzed the effect of 25 variables on TSV by partial least squares (PLS), from which we singled out 3 key factors. And the optimal multiple regression equation was derived to predict the TSV of HST occupants. Validation with an additional 20 subjects demonstrated a strong linear correlation (0.965) between the actual TSV and the predicted values, confirming the feasibility and accuracy of the developed prediction model. By integrating skin wettedness and ΔTd with skin temperature, the model provides a comprehensive approach to predicting thermal comfort in HST environments. This research contributes to advancing thermal comfort analysis in HST and offers valuable insights for optimizing HST system design and operation to meet passengers' comfort requirements. [ABSTRACT FROM AUTHOR]

In this study, the sliding grid method is used to simulate a 350 km/h high-speed train passing through a 350 m standard single-line tunnel. The cross-sectional pressure distribution ahead of the train is investigated, the three-dimensional characteristics and propagation mechanism of pressure waves are described based on iso-pressure surfaces, and a newly accurate pressure sensor layout is proposed. The results show that the farther the cross-section is from the train, the smaller the cross-sectional pressure difference is. Influenced by the shape of the train nose and tunnel cross-section, the pressure waves are not simple planar waves, but spherical waves that vary in complexity over the propagation process. As the pressure difference of the 16.6 m cross-section before the train is within 1 Pa, the pressure waves behind this cross-section are defined as planar waves. Besides, the pressure peak-to-peak value difference between the wall and construction clearance reaches 13% at 70–90 m cross-sections, so the pressure sensors should be placed on the surface of the appurtenances rather than on the tunnel wall. In summary, this study is significant for understanding the formation and transmission mechanisms of pressure waves and guiding the scientific layout of pressure sensors in tunnels. [ABSTRACT FROM AUTHOR]

Owing to the high energy density, lithium–sulfur batteries (LSBs) have attracted a lot of attention as a representative of new secondary batteries. However, LSBs also face some serious issues in practical applications such as the large volume expansion of S cathode, shuttle effect of lithium polysulfide (LPSs), and dendrite formation of lithium metal anode. In this work, hollow carbon sphere (HCS) was used as a framework, and CoSe2/Se nanorods were uniformly loaded on the HCS surface to form a 3D heterostructured composite (CS/Se/HCS). When used as an active sulfur host, the HCS is conducive to the transport of electrons and Li+; meanwhile, it can suppress the large volume expansion in the electrochemical performance. CoSe2 can effectively adsorb LPSs and accelerate the transformation of LPSs. We also investigated the effect of CoSe2/Se content on the electrochemical performance of the S electrode. Among different CS/Se/HCS samples, the CS/Se/HCS-0.3/S electrode exhibited the best electrochemical performance; at 1C rate, after 500 cycles, it presents a reversible capacity of 511 mA h g−1. This work provided a new idea for the combination of transition metal selenide and carbon materials, which can be used in LSBs and other energy storage devices. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysis technology has attracted much attention because it can directly use solar energy to produce clean hydrogen energy. Among many semiconductor materials, CdS not only has appropriate band positions to meet the redox potential of water splitting, but also has a suitable band gap to bring about excellent visible light absorption performance. Therefore, the research on CdS-based photocatalysts has become a hot topic in recent years, and their development is a significant part of future energy and environment research. However, CdS also has problems such as rapid recombination of photogenerated carriers and serious photocorrosion. In this paper, the recent work to improve the photocatalytic efficiency and stability of CdS is reviewed. The synthesis methods and modification strategies of CdS-based semiconductor photocatalysts for H2 evolution in solar energy are reviewed. Finally, the future prospects and challenges for the further development of CdS-based photocatalysts for H2 generation are also discussed. [ABSTRACT FROM AUTHOR]

The development of high-performance electrocatalysts is critical for the widespread applications of the sustainable energy technologies. In this context, single-atom catalysts (SACs) with isolated metal sites have attracted more attention because of their maximum atom utilization and remarkable electrocatalytic performance. However, the high surface energy often results in a low loading of the single metal atoms, limiting their practical applications. Herein, we give an up-to-date review on the progress for the SACs. The research progress of noble metal SACs, transition metal SACs, single-atom alloy SACs, and double metal SACs is summarized. The advantages and disadvantages of synthesis strategies including wet chemistry, atomic layer deposition, and high-temperature pyrolysis are discussed. We also propose some new research direction to obtain the high-performance SACs. It is expected to realize widely applications of SACs. [ABSTRACT FROM AUTHOR]

Recently, lithium–sulfur batteries (LSBs) have attracted much attention due to their high theoretical capacity, low cost, and abundant sulfur resources in nature. However, the low conductivity of sulfur and the "shuttle effect" of lithium polysulfides (LPSs) severely limited its commercial application. In this work, metal cobalt-decorated carbon cloth composites (Co/CC) were prepared by a simple hydrothermal method, and used as S host in LSBs. SEM and TEM images exhibited that countless petal-like metal cobalt nanoparticles were uniformly supported on carbon cloth fibers. The high electrical conductivity and special fiber structure of the carbon cloth are beneficial to the transmission of electrons and Li+ during electrochemical process. Meanwhile, the metal cobalt can adsorb the LPSs and accelerate its conversion. Therefore, compared with CC–S electrode, the Co/CC–S electrode presented better electrochemical performance, at a higher sulfur loading of 2.5 mg cm−2, and it delivered a reversible capacity of 249.0 mA h g−1 after 500 cycles at 1C with a low-capacity decay of 0.018% per cycle. Even at a high sulfur loading of 4.3 mg cm−2, the Co/CC–S electrode can present a reversible capacity of 273.3 mA h g−1 after 180 cycles. This work provided a new idea for the application of CC in flexible and wearable LSBs. [ABSTRACT FROM AUTHOR]

Purpose: Thoracic ossification of the ligamentum flavum (OLF) is an uncommon disease that mostly occurs in East Asians. Laminectomy is often considered when patients develop neuro-related symptoms but may associate with treatment-related complications. This study aimed to evaluate the efficacy and safety of unilateral biportal endoscopic (UBE) decompression treatment in patients with symptomatic OLF.Methods: From January 2020 to January 2021, patients with spinal cord compression symptoms and imaging-defined single-level thoracic OLF were enrolled in this study and received UBE decompression treatment. Their pre- and postoperative neurological statuses were evaluated by the modified Japanese Orthopaedic Association (mJOA) score, Visual Analog Scale (VAS) for leg pain, and Frankel grade.Results: Fourteen patients with an average age of 59.4 years were enrolled in the study. The mean operation time was 66.1 ± 15.4 minutes. Patients were followed up for at least one year after receiving the treatment. Our data suggested that their mJOA score (preop 6.2 ± 1.2, 1 year 8.5 ± 0.9; P < 0.001) and VAS score (preop 4.5 ± 2.0, 1 year 0.5 ± 0.9; P < 0.001) were significantly improved compared with that before operation. Cerebrospinal fluid leakage occurred in one patient, head and neck pain occurred in two patients, and hyperalgesia of lower limbs occurred in two patients. All these complications did not cause serious consequences.Conclusion: This primary study indicated that the UBE decompression treatment can achieve satisfactory clinical results in patients with thoracic OLF at single level and provide an alternative treatment option. [ABSTRACT FROM AUTHOR]