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Organic phase change materials (OPCMs) show immense application potential in solar energy storages owing to high energy storage capacity and latent heat efficiency. However, it is difficult to achieve prolonged energy storage due to the sensitivity of phase change to environmental temperature, and adding other substances will lead to a decrease in total energy density. Herein, azobenzene organic phase change composite (C14Azo-MA) was designed and prepared by doping myristic acid (MA) with an azobenzene derivative (C14Azo) featuring a carbon chain identical to that of the MA matrix. C14Azo-MA was systematically characterized by UV–Visible absorption spectroscopy and differential scanning calorimetry. The results showed that the C14Azo-MA retains the same isomerization properties as the C14Azo dopant. C14Azo-MA, due to its molecular photoisomerization and enhanced intermolecular interactions, establishes a new energy barrier and forms supercooling within C14Azo-MA, thereby allowing the storage of thermal energy below the crystallization temperature of MA. Notably, the C14Azo-MA exhibits a high energy density of 225.08 J g−1, surpassing that of pure MA by 14.42%. This work holds significant potential for solar energy storage applications.

Molecular solar thermal fuels (MOSTs) based on azobenzene derivatives have become one of the research hotspots for solar thermal conversion and storage due to their excellent cycling stability, resistance to photodegradation, and the capability to precisely adjust their absorption wavelengths, and other merits. Here, a novel MOST with connecting two azobenzene molecules by a short linkage (bis-AZO) has been proposed; the photoisomerization regulation and energy storage performance are studied experimentally in detail. The photoisomerization rate of the resultant MOST could be controlled by diverse irradiation intensities. The energy density for bis-AZO was 275.03 J g−1 at 100% isomerization degree, with excellent thermal and photochemical cycling stability. The macroscale heat release of bis-AZO loaded on fabric reached a temperature increase of about 4.3 °C. This research offers a new design strategy for increasing the energy density in azobenzene-based molecular solar thermal fuels.

Superoxide dismutase (SOD), also known as liver protein, is a substance widely distributed in various biological cells. It has the function of catalyzing the disproportionation reaction of superoxide free radicals. SOD can form an antioxidant chain together with peroxidase, catalase, and other substances in the body of organisms, and thus, is one of the indispensable important substances in the body of organisms. In this work, we provided a simple and fast visual electrochemiluminescence (ECL) sensor for SOD detection. CuInZnS quantum dots (QDs) worked as the ECL luminophore with hydrogen peroxide as co-reactant. In the sensing process, SOD and CuInZnS QDs on a glassy carbon electrode (GCE) competed with each other for hydrogen peroxide to produce superoxide during electrochemical luminescence, thus quenching the ECL signal of CuInZnS QDs. The proposed sensor can quantify SOD with a limit of detection (LOD) of 0.03 μg/mL. In addition, the change in the CuInZnS QDs ECL signal was easily observed with a smartphone camera. The results indicated that this sensor could effectively work in the detection of SOD in human blood.

In this paper, a multiaircraft path planning method framework for autonomous operation and distributed decision‐making was proposed. The core content of this framework consists of two parts: single‐aircraft path planning and multiaircraft path coordination. The path planning process includes airspace operational situation assessment, initial path generation based on operational situation, path optimization, and smoothing. A joint path planning algorithm of artificial potential field (APF) and particle swarm optimization is designed to overcome the inherent defects of the APF method and optimize the path to make it more resistant to disturbance. In the process of multiaircraft route coordination, a mixed strategy game model is constructed to promote the fair allocation of airspace resources among aircraft. The mathematical properties of the mixed strategy Nash equilibrium solution for this problem are presented. Finally, a simulation scenario is constructed based on the actual sector structure (ZSSSAR01) and running data to verify the effectiveness of the proposed method. The simulation results show that with the increasing proportion of aircraft operating in the autonomous mode, the length of the planned path increases first and then decreases, the airspace operation situation is gradually balanced in the spatial distribution, and the robustness of the planned path is gradually enhanced. The average path length of aircraft increases only by 9.15%, but the peak air traffic complexity can be reduced by 34.77%, and the number of highly utilized grids in airspace can be increased by 22.55%. And, the anti‐disturbance capability of this path is significantly improved. It proves that the multiaircraft distributed route planning method proposed in this paper has a good application prospect in future air traffic management.

•Spindle-related brain activation in the right middle temporal gyrus was significantly increased during N2 compared with N3.•Enhanced right middle temporal spindle-related brain activation in N2 negatively correlated with N2 sleep duration.•Utilized simultaneous EEG-fMRI to compare spindle-related brain activation between sleep stage N2 and N3 in two independent samples. The association between spindle metrics and sleep architecture differs during N2 vs. N3 sleep, the underlying neural mechanism is not clearly illustrated. Here, we tested the discrepancy in spindle-related brain activation between N2 and N3 within healthy college students (dataset 1: n = 27, 59 % females, median age 23 years), using simultaneous electroencephalography-functional magnetic resonance imaging (EEG-fMRI). To assess the replicability of the finding, we repeated the analysis among normal adults (independent dataset 2: n = 30, 50 % females, median age 32 years). The finding from dataset 1 indicated significantly increased blood-oxygen level-dependent signal in the right middle temporal gyrus during N2 compared with N3, which was well replicated in dataset 2. Furthermore, correlation analysis was performed to explore the association between this spindle-related brain activation and N2, N3 sleep duration during EEG-fMRI. We conducted the correlation analysis in N2 and N3, respectively. The negative association between spindle-related brain activation in the right middle temporal gyrus and sleep duration was only observed in N2. Our findings emphasize the unique role of spindle-related brain activation in the right middle temporal gyrus during N2 in shortening N2 sleep duration.

Background Among Chinese medical students, medical statistics is often perceived as a formidable subject. While existing research has explored the attitudes of Chinese postgraduate medical students towards statistics and its impact on academic performance, there is a scarcity of studies examining the attitudes of Chinese medical undergraduates on this subject. This study endeavors to scrutinize the attitudes of Chinese medical undergraduates towards statistics, assessing their ramifications on learning achievements, and delving into the influence of demographic factors. Methods 1266 medical undergraduates participated in this study, completing a questionnaire that included SATS-36 and additional queries. Furthermore, an examination was administered at the end of the medical statistics course. The analysis encompassed the SATS score and exam scores, examining both the overall participant population and specific demographic subgroups. Results Undergraduate medical students generally exhibit a favorable disposition towards statistics concerning Affect, Cognitive Competence, and Value components, yet harbor less favorable sentiments regarding the Difficulty component of SATS-36, aligning with previous research findings. In comparison to their postgraduate counterparts, undergraduates display heightened enthusiasm for medical statistics. However, they demonstrate a lower cognitive capacity in statistics and tend to underestimate both the value and difficulty of learning statistics. Despite these disparities, undergraduate medical students express a genuine interest in statistics and exhibit a strong dedication to mastering the subject. It is noteworthy that students’ attitudes toward statistics may be influenced by their major and gender. Additionally, there exists a statistically significant positive correlation between learning achievement and the Affect, Cognitive Competence, Value, Interest, and Effort components of the SATS-36, while a negative correlation is observed with the Difficulty component. Conclusion Educators should carefully consider the influence of attitudes toward statistics, especially the variations observed among majors and genders when formulating strategies and curricula to enhance medical statistics education.

Objectives The present study aimed to investigate sleep disturbance and mental health symptoms in elite athletes during the Beijing 2022 Winter Olympics preparatory period and whether they were associated with chronotype. Method This study included 428 elite Chinese winter sports athletes from the National Training Team (the response proportion was 94.1%) in August 2021. All participants completed self-reported scales, including Insomnia Severity Index (ISI) to assess sleep disturbance, the Generalized Anxiety Disorder Seven-Item (GAD-7) and the Patient Health Questionnaire Nine-Item (PHQ-9) to assess mental health symptoms (including anxiety and depression symptoms). Multivariable logistic regression models were applied to identify factors associated with sleep and mental health symptoms. Results In this study, we found that the point prevalence was 13.1% (95% confidence interval [CI] 11.5–14.7%) of insomnia, 20.1% (95% CI 18.2–22.0%) of depression, and 15.0% (95% CI 13.3–16.7%) of anxiety symptoms. Female sex (odds ratio 2.4 [95% CI 1.3–4.6], p  = 0.008) and age of 20–24 years (4.1 [1.5–10.9], p  = 0.005) were associated factors for insomnia symptoms. Evening chronotype was a significant contributing factor for insomnia (6.7 [2.0–22.6], p  = 0.002), depression (5.7 [2.2–15.1], p  < 0.001), and anxiety (7.4 [2.3–23.2], p  < 0.001) symptoms. Conclusions Disruptions were reported in the sleep and mental health of elite athletes during the preparation phase of the Beijing 2022 Winter Olympics. Evening chronotype may be a potential independent predictor of sleep and mental health changes for Chinese winter sport elite athletes in preparatory period, and further research is needed to generalize the results. These findings suggest that strategies to manage sleep and mental health better are critical.

The mortise-and-tenon joint prefabricated connection combines the assembly form of mortise-and-tenon joints and cast-in-place wet joints. It achieves reliable joint connections through small joint depths and lap-spliced reinforcement lengths. To study the impact resistance and damage characteristics of the assembled pier, a nonlinear finite element analysis was performed on the assembled and monolithic pier model piers to study the effects of mortise-and-tenon joint depths, lap reinforcement, and grout on the response of the piers to vehicle impact. The results showed that, after impact, the damage to the prefabricated pier was similar to that of the monolithic one. The failure mode involved opening of the seam at the impact face-pier bottom junction and localized concrete compression at the back-impact face pier bottom, and damage accumulated from the column base towards the column centerline. The mortise-and-tenon joint provided substantial horizontal constraint for the pier, imparting excellent resistance to lateral stiffness. Consequently, both piers showed nearly identical peak impact forces, yet the prefabricated pier exhibited a lesser degree of bending deformation compared to the monolithic one. The depth of the mortise-and-tenon joints was a critical factor affecting the impact response of the prefabricated bridge pier. When the depth reached 0.4D or more, it ensured good impact resistance and joint connection, enhancing energy absorption capability and reducing pier damage. The length of lap-spliced reinforcement significantly affected the overall integrity of prefabricated component connections. Lap lengths of 10d or more greatly reduced the probability of failure in the connection between pier columns and cap beams, lowering damage to the pier columns, joints, and pier cap beams, thus ensuring good impact resistance. The diameter of the lap-spliced reinforcement and the elastic modulus of the grouting material affected the local stiffness near the joints. Increasing the diameter of the lap-spliced reinforcement appropriately prevented excessive local damage, while altering the elastic modulus had minimal impact on improving pier damage.

Carburized Cr-Ni steel is widely used in the manufacture of components in many fields due to excellent performance, of which the service life has been a concern. In order to investigate the high-cycle-fatigue and very-high-cycle-fatigue properties of carburized Cr-Ni gear steel, axial loading fatigue tests were performed by QBG-100 with stress ratios of −1, 0 and 0.3. The Generalized Pareto distribution was used to evaluate the inclusion size of carburized Cr-Ni gear steel. Based on the stress ratio and the evaluated crack size, a new fatigue life prediction model for carburized Cr-Ni gear steels was constructed. The results show that the S–N characteristics of carburized Cr-Ni gear steel represent the continuously descending tendency. Based on the long crack propagation threshold and the instability propagation threshold of carburized Cr-Ni gear steel, the sizes of FGA, fisheye and surface smooth area (SSA) can be evaluated, respectively. In addition, the maximum size of surface and interior inclusion of carburized Cr-Ni gear steel are 17.50 μm and 6.46 μm with a cumulative probability of 99.9%. By validating the new established model, the prediction result is acceptable according to the good consistency between the predicted life and the experimental life.

The size and depth of defects significantly affect fatigue performance; the main purpose of this article is to clarify the effect of stress correction factors caused by defects on the fatigue life of α + β Type titanium alloy welded joints. In order to investigate the fatigue characteristics of α + β Type titanium alloy welded joints, axial constant amplitude loading fatigue tests were performed with a stress ratio of −1. The test results show that the fatigue life continues to increase as the stress amplitude decreases, and the failure modes can be classified into two types: interior failure and surface failure. A fatigue parameter (λ) determined by both defect depth and size was proposed which allowed for a good generalization of the data point distribution in short and long-life regions. The stress correction factor (W) related to the S–N characteristics was constructed by combining the λ and average defect size, and it effectively improved the dispersion of the test data. Continuing, the fatigue life prediction model was established under the condition that the defect type and size can be estimated or detected on the basis of the dislocation energy method. The results indicated that the evaluated values of the new life model associated with W are in good agreement with the test results.