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Structural bidimensional transition-metal carbides and/or nitrides (MXenes) have drawn the attention of the material science research community thanks to their unique physical-chemical properties. However, a facile and cost-effective synthesis of MXenes has not yet been reported. Here, using elemental precursors, we report a method for MXene synthesis via titanium aluminium carbide formation and subsequent in situ etching in one molten salt pot. The molten salts act as the reaction medium and prevent the oxidation of the reactants during the high-temperature synthesis process, thus enabling the synthesis of MXenes in an air environment without using inert gas protection. Cl-terminated Ti 3 C 2 T x and Ti 2 CT x MXenes are prepared using this one-pot synthetic method, where the in situ etching step at 700 °C requires only approximately 10 mins. Furthermore, when used as an active material for nonaqueous Li-ion storage in a half-cell configuration, the obtained Ti 2 CT x MXene exhibits lithiation capacity values of approximately 280 mAh g −1 and 160 mAh g −1 at specific currents of 0.1 A g −1 and 2 A g −1 , respectively. A facile and cost-effective synthesis of MXenes is not yet available. Here, the authors propose a one-pot molten salt-based method of MXenes synthesis from elemental precursors in an air atmosphere. Li-ion storage properties of the MXenes are also reported and discussed.

A novel algorithm (CP-QRRT*) is proposed for the path planning tasks of hyper-redundant manipulators (HRMs) in confined spaces, addressing the issues of unmet joint angle constraints, redundant planning paths, and long planning times present in previous algorithms. First, the PSO algorithm is introduced to optimize the random sampling process of the RRT series algorithms, enhancing the directionality of the random tree expansion. Subsequently, the method of backtracking ancestor nodes from the Quick-RRT* algorithm is combined to avoid getting trapped in local optima. Finally, a constraint module designed based on the maximum joint angle constraints of the HRM is implemented to limit the path deflection angles. Simulation experiments demonstrate that the proposed algorithm can satisfy the joint angle constraints of the HRM, and the planned paths are shorter and require less time.

Background Strengthening health systems and ensuring equity and access to human resources can significantly reduce maternal and child mortality and improve maternal and child health outcomes. This mixed-methods study aimed at the quantity, quality, and equity of the allocation of human resources for health (HRH) in Chinese maternal and child healthcare institutions from 2002 to 2021 while providing a reference for optimally allocating HRH in the new era. Methods Relying on health-related data obtained from statistical yearbooks in 2003–2022, the study analysed the allocation status using descriptive statistics, examined the allocation equity with the Gini coefficient and the Health resource agglomeration degree/Health resource population agglomeration degree (HRAD/HRPAD). Finally, the study predicted the future allocation trend by compiling a grey prediction model GM (1,1). Results HRH quantity in Chinese maternal and child healthcare institutions experienced steady growth. However, the composition of educational background and professional titles was unreasonable. The quality structure needs to be further optimized. The equity of demographic allocation (Gini < 0.2) was superior to the geographic allocation (Gini = 0.631–0.678), with significant regional differences. The HRAD values of HRH in different regions were as follows: eastern region (3.50–3.70) > central region (1.69–1.92) > western region (0.36–0.44); HRPAD (2021): western region (1.150) > central region (0.991) > eastern region (0.912). The equity of sparsely populated regions was superior to that of densely populated regions. The HRH future allocation trend is positive. Conclusions Emphasis should be placed on the status quo of unreasonable allocation and unbalanced distribution. Careful consideration must be given to factors like service population, service radius, economic development, and population mobility while considering demographic and geographic equity to promote the reasonable allocation and full utilisation of HRH.

Background Rapid economic development and urbanization in China have improved population health outcomes, but exacerbated inequalities in the allocation of public health human resources (PHHR). Existing studies largely rely on static measures and offer limited insights into the mechanisms driving these disparities. This study systematically identifies and quantifies the determinants influencing public health workforce allocation in China, aiming to provide empirical evidence to guide policy interventions. Methods This study analyzed the allocation of PHHR across 31 Chinese provinces from 2018 to 2022, employing four inequality indices: Gini coefficients (Gini), concentration index (CI), absolute Gini (AGini), and absolute concentration index (ACI). Two-way analysis of variance (ANOVA) and bivariate correlation analyses were used to assess temporal and regional variations. The recentered influence function-index-ordinary least squares (RIF-I-OLS) method was applied to decompose these inequality indices. This approach quantified the contributions of key factors, including the illiteracy rate among the population aged 15 years and above, government health expenditure, number of professional public health institutions (PPHI), mortality rate from Class A and B infectious diseases (IDs), and life expectancy (LE), while distinguishing between characteristic effects and coefficient effects. Results Between 2018 and 2019, inequity in PHHR allocation increased (Gini: 0.3792–0.3844; CI 0.0215–0.0495). In contrast, from 2019 to 2022, allocation equity improved (Gini: 0.3715; CI 0.0279). A greater number of PPHIs, a lower mortality rate of class A and B IDs, and longer LE helped mitigate inequalities, whereas a lower illiteracy rate among the population aged ≥ 15 years and increased governmental health expenditure exacerbated disparities. Inequality in PHHR allocation during 2018–2019 was primarily driven by characteristic effects, whereas in 2021–2022, coefficient effects became dominant, underscoring the role of institutional and systemic factors. Conclusions While the equity of PHHR allocation in China has shown modest improvement, structural and institutional factors remain key determinants of lingering inequities. This highlights the need for targeted policies to optimize the distribution of the public health workforce.

Ocean development is an effective and practical way to address resource issues, such as food, fuel, and land shortage. The current work proposed using kaolin-based biocement to stabilize calcareous sand which is always the main component of the foundations of ocean engineering. Five kinds of kaolin concentrations (0 g/L, 10 g/L, 20 g/L, 50 g/L, and 100 g/L) were selected to stabilize calcareous sand via the unsaturated percolation method. Besides, the saturated strength was determined to mimic the practical situations. The results showed that treatment cycles and raw materials can be reduced to obtain a given saturated strength when moderate kaolin is added. That is, the cost-performance of the MICP is improved. Besides, the maximum attainable saturated strength can be enlarged when a small dosage of kaolin is added. The distribution of precipitate contents along with the height of the specimens was also determined by the buoyancy method. Furthermore, a critical permeability range, i.e., 1.11∼2.70×10-4 m/s, is also distinguished from the permeability tests. The percolation method is not suitable for sand with a permeability smaller than this range.

The negative effects of obesity and excess body fat on bone mineral density (BMD) have been widely reported. As opposed to waist circumference (WC) or body mass index (BMI), weight-adjusted waist index (WWI) is a superior method for assessing obesity. WWI also indicates centripetal obesity independently of the weight of the individual. An investigation of WWI and adolescents’ BMD was conducted in this study. The National Health and Nutrition Examination Survey (NHANES) 2011–2018 provided the data for this cross-sectional investigation. In this study, weighted multivariate logit models were employed to assess the correlation between teenage BMD and WWI. Additionally, we conducted interaction tests and subgroup analysis. Through multivariate linear regression, we discovered that WWI was negatively linked with lumbar, trunk, and total BMD but not pelvis BMD in this study, which included 6828 subjects. We found that each unit increase in WWI resulted in a lumbar BMD decline of 0.04 g/cm 2 (95%CI −0.04, −0.04), a trunk BMD decrease of 0.03 g/cm 2 (95%CI −0.03, −0.02), and a total BMD decrease of 0.02 g/cm 2 (95%CI −0.02, −0.02). In conclusion, in US teenagers, there were negative connections discovered between WWI and lumbar, trunk, and total BMD, but not pelvis BMD.

In this paper, the mathematical model of the aviation pressure servo valve controlled actuator system(APSVCAS) considering nonlinearity is established based on a jet pipe pressure servo valve in this article. And the dynamic characteristics and stability boundary of APSVCAS are analyzed, which provides theoretical guidance for the actual composition and the determination of parameters. Firstly, a jet-tube two-stage pressure servo valve for aviation hydraulic system is designed, and an accurate model of APSVCAS is established considering multiple nonlinear factors. Meantime, the influence of 34 parameters on the dynamic characteristics of the system is analyzed by using the second-order sensitivity analysis method. And the key parameters that significantly affect the dynamic characteristics of the system are extracted. Based on this, the system stability discrimination method is proposed from the perspectives of frequency domain and time domain, and the stability boundary of key parameters is obtained. Finally, the theoretical analysis results are verified on the experimental platform of APSVCAS. The experimental results show that the mathematical model of APSVCAS considering nonlinearity has satisfactory accuracy. Concomitantly, it is verified that the parameters’ stability boundary condition based on the sensitivity analysis method meet the stable output effect of the system under multiple working conditions.

Thermal cameras are known for their ability to overcome lighting constraints and provide reliable thermal radiation images. This capability facilitates methods for depth and ego-motion estimation, enabling efficient learning of poses and scene structures under all-day conditions. However, the existing studies on depth prediction for thermal images are limited. In practical applications, thermal cameras capture sequential frames. Unfortunately, the potential of this multi-frame aspect is underutilized by the previous methods, resulting in limitations on the depth prediction accuracy of thermal videos. To leverage the multi-frame advantages of thermal videos and to improve the accuracy of monocular depth estimation from thermal images, we propose a framework for self-supervised depth and ego-motion learning from multi-frame thermal images. We construct a multi-view stereo (MVS) cost volume from temporally adjacent thermal frames. The construction process is adjusted based on the estimated pose, which serves as a motion hint. To stabilize the motion hint and improve pose estimation accuracy, we design a motion enhancement module that utilizes self-generated poses for additional supervisory signals. Additionally, we introduce RGB images in the training phase to form a multi-spectral loss, thereby augmenting the performance of the thermal model. The experimental results, conducted on a public dataset, demonstrate the proposed method’s accurate estimation of depth and ego-motion across varying light conditions, surpassing the performance of the self-supervised baseline.

Supercapacitors have emerged as a prominent area of research in energy storage technology, primarily because of their high power density and notable stability compared to batteries. However, their practical implementation is hindered by their low energy densities and insufficient long‐term stability. In this study, bulk porous Nb4N5 and Ta3N5 single crystals with excellent pseudocapacitance and electrical conductivity are successfully prepared by solid‐phase transformation method. These monolithic porous single crystals (PSC) exhibit a long‐range ordered crystalline architecture and substantial specific surface area, which facilitate rapid charge transport and ion diffusion within the electrolyte‐permeated crystal lattice. Notably, the areal capacitance of the porous Nb4N5 single crystals is 12.9 F cm−2 at a current density of 6 mA cm−2 and 35.08 F cm−2 at a scan rate of 1 mV s−1. Furthermore, the energy density reached 1.79 mWh cm−2 at a power density of 20 mW cm−2, demonstrating their high energy storage capability. Moreover, these porous Nb4N5 single crystals exhibited robust capacitance retention and exceptional cycling stability, making them promising candidates for use as electrodes in energy storage applications. These results underscore the significant potential of porous metal nitride single crystals in advancing the field of capacitive energy storage. This study develops centimetre‐scale porous nitride single crystals, integrating single‐crystal stability with high surface area. Their well‐ordered lattice structure and interconnected porosity significantly enhance the capacitance and durability of supercapacitor electrodes. The findings underscore the potential of transition metal nitrides exhibiting high pseudocapacitance and long‐term stability, thereby advancing the development of efficient and robust pseudocapacitance electrodes.

Background The duration of sleep is linked to a range of disorders. Osteoarthritis (OA) stands as one of the most prevalent forms of arthritis and serves as a leading cause of disability. The correlation between the duration of sleep and OA remains ambiguous. Research indicates that waist circumference correlates with sleep duration and OA, respectively. This study aimed to investigate the association of sleep duration with OA and the mediated effect of waist circumference. Methods The study sample comprised adults who were participants in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2018. Insufficient sleep is characterized by a duration of less than seven hours, whereas 7–8 h is considered appropriate, and 9 h or more is categorized as a long sleep duration. Three models were employed in this study. Model 1 was not adjusted for any covariates, while Model 2 was adjusted for sex, age, and race. Model 3 has been adjusted to account for all covariates. Utilizing multivariable logistic regression, subgroup analysis, interaction tests and smoothing curve fitting, the correlation between sleep duration and OA was explored. The mediating effect of waist circumference on the association between sleep duration and OA was investigated through mediation analysis. Results In this study, 9380 did not have OA, while 2424 were diagnosed with the ailment. After multivariable adjustment, the odds ratios (OR) for OA were 1.19 (95% CI 1.06, 1.34; P  = 0.0026) for people with insufficient sleep duration and 1.18 (95% CI 1.03, 1.35 P  = 0.0142) for participants with long sleep duration. Sleep duration and the incidence of OA were found to be related in a U-shaped manner. Additionally, 12.1% of the correlation between sleep duration and OA appeared to be mediated by waist circumference. Conclusions Increased OA was found to be correlated in a U-shaped manner with sleep duration in the middle-aged and elderly cohorts. Both insufficient and long sleep duration contribute to an elevated risk of developing OA. A potential mediating factor in the association between OA and sleep duration is waist circumference. Focus on sleep health and visceral obesity in middle-aged and older adults is necessary.