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Milti-principal cation oxide ceramics with excellent mechanical properties for potential applications in coating materials. A Multi-principal cation mullite (MPCM) ceramic is synthesized with MgO, TiO 2 , Cr 2 O 3 , ZrCl 2 O·8H 2 O and Al 2 O 3 , SiO 2 via solid state reaction at 1600 °C. It is determined that 96.9 % of the sample composition is mullite. MPCM ceramic exhibits higher compressive strength (981 ± 19 MPa) and fracture toughness (3.37 ± 0.05 MPa∙m1/2), the compressive strength has raised by 453 MPa, and the added value of solution strengthening (452 MPa) is gained by using solid-solution strengthening theory. The improvement of compressive strength is mainly due to the solution strengthening effect of the four oxides(Mg, Ti, Zr, Cr), and the improvement of fracture toughness is caused by the grain hindrance during crack propagation. Moreover, its application at the high-temperature resistant coating is verified through experimentation. The interfacial binding force, as an important mechanical property index for ceramics, is researched. In this study, pure mullite powder and MPCM powder are coated onto the refractory TaWNbV alloy matrix by slurry coating method, and the interfacial toughness of the two coatings mingled with the matrix is calculated to be 72.9 and 62.6 J·m−2, respectively. The "shrinking cylinder" model is introduced to interpret the oxidative weight gain mechanism of the two coatings. [ABSTRACT FROM AUTHOR]

Multi‐dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force‐induced optical and electrical dual responses would provide unique opportunities to multi‐dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high‐energy excitation source brings significant challenges to the applicability of multi‐dimensional force sensors. Here we reported the mechanical energy‐driven and sunlight‐activated materials with force‐induced dual responses, and investigated the underlying mechanisms of self‐sustainable force sensing. Theoretical analysis and experimental data unraveled that trap‐controlled luminescence and interfacial electron transfer play a major role in force‐induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual‐mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high‐energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi‐dimensional sensing ability of the sensor. Overall, this self‐powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world. [ABSTRACT FROM AUTHOR]

Multi‐dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force‐induced optical and electrical dual responses would provide unique opportunities to multi‐dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high‐energy excitation source brings significant challenges to the applicability of multi‐dimensional force sensors. Here we reported the mechanical energy‐driven and sunlight‐activated materials with force‐induced dual responses, and investigated the underlying mechanisms of self‐sustainable force sensing. Theoretical analysis and experimental data unraveled that trap‐controlled luminescence and interfacial electron transfer play a major role in force‐induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual‐mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high‐energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi‐dimensional sensing ability of the sensor. Overall, this self‐powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world. [ABSTRACT FROM AUTHOR]

The rocket sled, as a ground dynamic test system, combines the characteristics of the wind tunnel test and the flight test. However, some practical factors, such as shock wave interference, ground effect, and high-intensity aerodynamic noise will cause serious interference and even failure of the uniformly distributed sensors during horizontal sliding in a wide speed range. The AGARD HB-2 standard model is employed as the payload to simulate the aerodynamic and aeroacoustic characteristics during the variable acceleration period, aiming to optimize the test sensors layout. It is observed that in the high Mach number flow fields, strong coupling behaviors among complex waves will occur. The peak of wake vortex strength will appear at 1.5 s and gradually diminish over time. In addition, when the vortex between the load and the booster is monitored, its position shifts forward in the subsonic stage, then gradually moves backward and expands in the supersonic stage. Acoustic directivity is pronounced at subsonic and transonic speeds, pointing towards 75° and 135° relative to the sliding speed, respectively. These results can provide technical support for sensor layout and high-precision testing in rocket sled tests. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSNon-thermal atmospheric plasma (NTAP) has been proven to be an effective anti-tumor tool, with various biological effects such as inhibiting tumor proliferation, metastasis, and promoting tumor cell apoptosis. At present, the main conclusion is that ROS and RNS are the main effector components of NTAP, but the mechanisms of which still lack systematic summary. Therefore, in this review, we first summarized the mechanism by which NTAP directly or indirectly causes an increase in intracellular RONS concentration, and the multiple pathways dysregulation (i.e. NRF2, PI3K, MAPK, NF-κB) induced by intracellular RONS. Then, we generalized the relationship between NTAP induced pathways dysregulation and the various biological effects it brought. The summary of the anti-tumor mechanism of NTAP is helpful for its further research and clinical transformation.Non-thermal atmospheric plasma (NTAP) acts on NADPH oxidase and catalase.The feeding gas and parameters of NTAP affect its impacts on the signaling pathways.The impacts of NTAP and RONS on pathways are not always consistent.NTAP can trigger various anti-tumor biological effects.Non-thermal atmospheric plasma (NTAP) acts on NADPH oxidase and catalase.The feeding gas and parameters of NTAP affect its impacts on the signaling pathways.The impacts of NTAP and RONS on pathways are not always consistent.NTAP can trigger various anti-tumor biological effects. [ABSTRACT FROM AUTHOR]

AbstractIn this paper, we consider an almost cosymplectic 3-manifold M such that its scalar curvature is invariant along the Reeb vector field. We prove that if the Reeb vector field of M is harmonic, then M is conformally flat if and only if it is locally isometric to the product ℝ × N2(c), where N2(c) is a Kähler surface of constant sectional curvature c. Almost cosymplectic 3-manifolds on which the Reeb vector field satisfies the h-a condition together with conformal flatness are also classified. [ABSTRACT FROM AUTHOR]

Objective: Although the TyG index is a reliable predictor of insulin resistance (IR) and cardiovascular disease, its effectiveness in predicting major adverse cardiac events in hospitalized acute coronary syndrome (ACS) patients has not been validated in large-scale studies. In this study, we aimed to explore the association between the TyG index and the occurrence of MACEs during hospitalization. Methods: We recruited ACS patients from the CCC-ACS (Improving Cardiovascular Care in China-ACS) database and calculated the TyG index using the formula ln(fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). These patients were classified into four groups based on quartiles of the TyG index. The primary endpoint was the occurrence of MACEs during hospitalization, encompassing all-cause mortality, cardiac arrest, myocardial infarction (MI), and stroke. We performed Cox proportional hazards regression analysis to clarify the correlation between the TyG index and the risk of in-hospital MACEs among patients diagnosed with ACS. Additionally, we explored this relationship across various subgroups. Results: A total of 101,113 patients were ultimately included, and 2759 in-hospital MACEs were recorded, with 1554 (49.1%) cases of all-cause mortality, 601 (21.8%) cases of cardiac arrest, 251 (9.1%) cases of MI, and 353 (12.8%) cases of stroke. After adjusting for confounders, patients in TyG index quartile groups 3 and 4 showed increased risks of in-hospital MACEs compared to those in quartile group 1 [HR = 1.253, 95% CI 1.121–1.400 and HR = 1.604, 95% CI 1.437–1.791, respectively; p value for trend < 0.001], especially in patients with STEMI or renal insufficiency. Moreover, we found interactions between the TyG index and age, sex, diabetes status, renal insufficiency status, and previous PCI (all p values for interactions < 0.05). Conclusions: In patients with ACS, the TyG index was an independent predictor of in-hospital MACEs. Special vigilance should be exercised in females, elderly individuals, and patients with renal insufficiency. [ABSTRACT FROM AUTHOR]

It remains a huge challenge to efficiently recycle the printed circuit boards (PCBs) because of the diversity and complexity of the PCBs in terms of material composition. The recycling of PCBs highly depends on the design of the polymers that make up the polymer substrates and conductive pastes. Herein, closed‐loop recyclable plastics for use as the polymer substrates and for the preparation of the conductive pastes are fabricated by dynamically cross‐linking phenylboronic acid‐functionalized poly(methylmethacrylate) (PMMA‐B) and poly(urea‐urethane) (PUU‐B) with boroxines. The closed‐loop recyclable plastic, which is denoted as PMMA‐PUU exhibits a breaking strength of 71.0 MPa and Young's modulus of 1.8 GPa. Because of the dynamic nature of boroxines, the PMMA‐PUU0.6 plastic can be depolymerized in the N, N‐dimethylacetamide/ethanol mixture solvent. The depolymerized PMMA and PUU can be efficiently recovered in high yields and purity through their solubility differences in selective solvents. Conductive pastes suitable for printing of electrical circuits are fabricated through complexation of Ag particles with PMMA‐PUU. PCBs composed of PMMA‐PUU substrates and PMMA‐PUU‐based conductive pastes are flexible, healable, and recyclable. The closed‐loop recycling of the PCBs enables the collection of highly purified Ag particles, PMMA‐B, and PUU‐B monomers even when the PCBs are mixed with polymer wastes. [ABSTRACT FROM AUTHOR]

As a swarm-based metaheuristic algorithm, the crow search algorithm (CSA) has attracted a lot of attention owing to its simplicity and flexibility. However, CSA tends to have low efficiency. To improve the optimization efficiency, this article proposes a modified version of CSA based on group strategy with an adaptive mechanism (GCSA). On this basis, crows are divided into multiple competing groups, and are assigned different roles and statuses. Then, the group strategy including different search modes is implemented to increase the solution diversity and search efficiency. Moreover, benefiting from the adaptive mechanism, the search range of crows changes in different stages to balance exploration and exploitation capabilities. To evaluate the performance of the proposed algorithm, 35 benchmark test functions (including 10 CEC2020 functions) and three engineering design problems are solved by GCSA and 11 other algorithms. The results prove that GCSA generally provides more competitive results than other metaheuristic algorithms. [ABSTRACT FROM AUTHOR]

Purpose: Autoimmunity is a significant feature of APDS1 patients. We aimed to explore the pathogenic immune phenotype and possible mechanisms of autoimmunity in APDS1 patients. Methods: The clinical records and laboratory data of 42 APDS1 patients were reviewed. Immunophenotypes were evaluated by multiparametric flow cytometry. Autoantibodies were detected via antigen microarray analysis. Results: A total of 42 children with PIK3CD gene mutations were enrolled. Immunological tests revealed increased proportions of effector memory cells (86%) and central memory cells (59%) among CD4+ T cells; increased proportions of effector memory cells (83%) and terminally differentiated effector memory T cells (38%) among CD8+ T cells. Fewer CD3+ T cells and B cells and higher IgG levels were reported in patients with autoimmunity. The proportion of Tregs was decreased, and the proportions of Th9, Tfh, and Tfr cells were increased in APDS1 patients. Among APDS1 patients, higher proportion of Th2 and Tfr cells were found in those with autoimmunity. The proportions of CD11c+ B and CD21lo B cells in patients with autoimmunity were significantly increased. Antigen microarray analysis revealed a wide range of IgG/IgM autoantibodies in patients with APDS1. In patients with autoimmunity, the proportion of Tfr might be positively correlated with autoantibodies. Conclusions: The pathogenic immune phenotype of APDS1 patients included (1) deceased CD3+ T-cell and B-cell counts and increased IgG levels in patients with autoimmunity, (2) an imbalanced T helper cell subset, (3) increased proportions of autoreactive B cells, and (4) distinct autoantibody reactivities in patients with autoimmunity. [ABSTRACT FROM AUTHOR]

With the continuous warming of the global climate, expanding the use of renewable energy has become one of the main social responsibilities. However, as the number of installed wind turbines and their physical dimensions continue to increase, the issue of generated noise has become increasingly significant in influencing the acceptance and endorsement of wind power projects by neighboring communities. In this paper, we investigated the noise generated by two wind turbine units with rated powers of 1.5 MW and 4.5 MW and analyzed the variations in low-frequency noise during their operation and shutdown periods. This research shows that the power of a single unit has a significant impact on the low-frequency noise emitted into the environment. Compared with 1.5 MW wind turbines, 4.5 MW wind turbines generate more low-frequency noise when operating at the same wind speed. Further analysis of the narrowband frequency spectra and one-third octave spectra of the measured noise indicates that the low-frequency noise from the 4.5 MW wind turbine increases significantly in the range of approximately 80 Hz to 300 Hz, with more pronounced variations below 250 Hz corresponding to changes in wind speed. However, the overall variations in low-frequency noise with wind speed are not as notable as those observed for the 1.5 MW wind turbine. Due to the relatively weak attenuation of low-frequency noise in the atmosphere, the higher low-frequency content of large wind turbines may cause more distress to residents near wind farms. The result of this study emphasizes that in the planning and design of wind power projects, in addition to considering the efficiency of single-unit power generation and the contribution of renewable energy, it is also necessary to pay full attention to noise emission issues to ensure that the project is widely supported and accepted in the community. [ABSTRACT FROM AUTHOR]

The sequential approximate optimization (SAO) method is widely adopted in aircraft optimization design, whose further improvement in efficacy and efficiency has encountered bottlenecks. In this paper, a collaboratively iterative sequential approximate optimization (CISAO) method with field metamodel (FM) accelerating computational fluid dynamics (CFD) is proposed for aerodynamic optimization problems to enhance the coupling between metamodels and CFD high-fidelity models (HFMs). In this method, the field metamodel is used to predict the flow field distributions with respect to the design variables to accelerate the numerical solution of CFD HFMs. Two benchmark aerodynamic optimization cases are performed to validate the proposed method. The time costs for single CFD HFMs in the two test cases are shortened by 37.76% and 12.11%, respectively, and the total time costs of the two test cases are shrunk by 64.11% and 44.47% compared with the conventional SAO method. The optimization results indicate that the proposed method significantly reduces the time costs and improves the optimization efficiency. The proposed method shows a promising prospect in aircraft optimization design. [ABSTRACT FROM AUTHOR]

It is not clear how the number of 15 N-injection needles affects the estimated results of gross N transformation rates in the presence of plants. To evaluate this, a 15 N tracing study of sandy loam soil and a silty loam soil in the presence of maize (Zea mays L., cv. "Zhengdan 958") was conducted and the Ntraceplant tool was used to quantify gross N transformation rates. Our results showed that the number of 15 N-injection needles could significantly influence the estimated results of gross N transformation rates in the studied soil–plant systems. There was no discernible difference in the gross rates of N mineralization (Min), the oxidation of NH4+ to NO3− (ONH4), the oxidation of recalcitrant organic-N to NO3− (ONrec), the NH4+ and NO3− plant uptake between 4-needle and 6-needle injections for both studied soils. However, for the 1-needle and 2-needle injections in the silty loam soil, Min was significantly lower than the 4-needle and 6-needle injections. While, in sandy loam soil, Min measured with 1-needle injection was significantly higher than the 4-needle and 6-needle injections. The ONH4 and ONrec also varied for the 1-needle and 2-needle injections, compared to the 4-needle and 6-needle injections. The total plant N uptake rate declined with the increase in the number of injection needles. Based on these results and considering the simplicity of the experimental procedure, we suggest that the 4-needle injection could be used in the 15 N tracing studies conducted in pot (diameter = 6.4 cm in this study) experiments with plants, i.e., one needle for about 8 cm2. [ABSTRACT FROM AUTHOR]

Exogenous nitrogen and carbon can affect plant cell walls, which are composed of structural carbon. Sucrose synthase (SUS), invertase (INV), hexokinase (HXK), phosphoglucomutase (PGM), and UDP-glucose pyrophosphorylase (UGP) are the key enzymes of sucrose metabolism involved in cell wall synthesis. To understand whether these genes are regulated by carbon and nitrogen to participate in structural carbon biosynthesis, we performed genome-wide identification, analyzed their expression patterns under different carbon and nitrogen treatments, and conducted preliminary functional verification. Different concentrations of nitrogen and carbon were applied to poplar (Populus trichocarpa Torr. and Gray), which caused changes in cellulose, lignin, and hemicellulose contents. In poplar, 6 SUSs, 20 INVs, 6 HXKs, 4 PGMs, and 2 UGPs were identified. Moreover, the physicochemical properties, collinearity, and tissue specificity were analyzed. The correlation analysis showed that the expression levels of PtrSUS3/5, PtrNINV1/2/3/5/12, PtrCWINV3, PtrVINV2, PtrHXK5/6, PtrPGM1/2, and PtrUGP1 were positively correlated with the cellulose content. Meanwhile, the knockout of PtrNINV12 significantly reduced the cellulose content. This study could lay the foundation for revealing the functions of SUSs, INVs, HXKs, PGMs, and UGPs, which affected structural carbon synthesis regulated by nitrogen and carbon, proving that PtrNINV12 is involved in cell wall synthesis. [ABSTRACT FROM AUTHOR]

Complex immune microenvironment of diabetic wound possesses polarization misalignment of macrophages and excessive inflammatory response, which prolong the healing process. Consequently, developing hydrogel dressings with immunoregulatory ability shows huge potential in clinical management of diabetic wound. Nevertheless, recent immunoregulatory strategies are mainly focusing on switching the proinflammatory M1‐type to anti‐inflammatory M2‐type macrophages by using high‐cost dressings composed of cytokines and cells. Considering the hyperpolarized M1 macrophages of diabetic wounds as wild grass of wasteland, a burning grass and removing root immunoregulatory strategy toward wound healing is developed based on dopamine‐manganese dioxide nanoparticle incorporated high molecular weight hyaluronic acid (HHA) hydrogel. The self‐healing and injectable hydrogel is formed by boronate ester bonds between the HHA grafted with phenylboronic acid and polyvinyl alcohol. Notably, in vitro and vivo results confirm that the HHA components can burn the grass by switching M1 to M2 in the inflammatory microenvironment while the dopamine‐manganese dioxide nanoparticles can remove the root by relieving M1 polarization through eliminating reactive oxygen species. The comprehensive immunoregulation ability enables the hydrogel as effective therapeutic that improves wound healing, and shows reliable potential in clinical dressings for the management of diabetic wounds. [ABSTRACT FROM AUTHOR]

Heat exchangers have a very wide range of applications in many industrial fields, so the rational design and the performance are to improve the heat exchanger energy efficiency and reduce the production cost of an important means. In this paper, the heat transfer mechanism of pulsation is revealed by simulating and analyzing the effects of three pulsation parameters: volumetric flow rate, pulsation frequency, and pulsation amplitude on the flow and heat transfer of a wavy-walled tube heat exchanger, with the study focusing on the instability behavior that affects the heat transfer mechanism. The results reveal that the combined heat transfer performance of the wavy-walled tube heat exchanger is about 8.2% higher than that of the straight-walled tube heat exchanger. The flow field of the heat exchanger is more fully developed under the pulsating flow field, and its performance evaluation coefficients (PECs) are all greater than 1. It is also found that with the increase in the volume flow rate Qv, the heat transfer enhancement coefficient and PEC first increase and then decrease, and reach the maximum value near Qv = 2.0 m3/h; with the increase in the amplitude A, the vortex and heat transfer enhancement coefficient inside the heat exchanger increase, but the integrated heat transfer performance of the heat exchanger is gradually weakened; with the increase in the frequency fT, the heat transfer enhancement coefficient and PEC first increase gradually, but the increase gradually decreases and levels off in the later stages, reaching a maximum value near fT = 0.5 Hz. Meanwhile, the field coefficients of the wavy-walled tube heat exchanger were analyzed and found to be much smaller than 1, with an order of magnitude of 10−4, and the results also showed that the field coefficients were inversely proportional to the volume flow rate and directly proportional to the amplitude of pulsation and that the field coefficients showed a tendency of increasing and then decreasing with the change of pulsation frequency and reached a maximum value near fT = 0.5 Hz. This work provides an important reference for current manufacturing industries to optimize heat exchanger sizing and develop efficient thermal management systems. [ABSTRACT FROM AUTHOR]

Objective: We investigated the association between dietary oxidative balance score (DOBS) and mortality and whether this association can be modified by sleep duration. Design: We calculated DOBS to estimate the overall oxidative effects of the diet, with higher DOBS reflecting more antioxidant intake and less pro-oxidant intake. Cox proportional hazards models were employed to examine the associations between DOBS and all-cause, CVD and cancer mortality in the general population and people with different sleep durations. Setting: Prospective analysis was conducted using data from the US National Health and Nutrition Examination Survey (NHANES, 2005–2015). Participants: A total of 15 991 US adults with complete information on dietary intake, sleep duration and mortality were included. Results: During a median follow-up of 7·4 years, 1675 deaths were observed. Participants in the highest quartile of DOBS were significantly associated with the lower risk of all-cause mortality (hazard ratio (HR) = 0·75; 95 % CI 0·61, 0·93) compared with those in the lowest. Furthermore, we found statistically significant interactions between DOBS and sleep duration on all-cause mortality (P interaction = 0·021). The inverse association between DOBS and all-cause mortality was significant in short sleepers (HR = 0·66, 95 % CI 0·48, 0·92), but not in normal and long sleepers. Conclusions: Our study observed that higher DOBS was associated with lower all-cause mortality, and this association appeared to be stronger among short sleepers. This study provides nutritional guidelines for improving health outcomes in adults, especially for short sleepers. [ABSTRACT FROM AUTHOR]

As an advanced interaction mode, gestures have been widely used for human–computer interaction (HCI). This paper proposes a multi-objective optimization method based on the objective function J C P to solve the inconsistency between the gesture comfort J C S and measurement precision J P H in the gesture interaction. The proposed comfort model C S takes seventeen muscles and six degrees of freedom into consideration based on the data from muscles and joints, and is capable of simulating the energy expenditure of the gesture motion. The C S can provide an intuitive indicator to predict which act has the higher risk of fatigue or injury for joints and muscles. The measurement precision model ∆ P H is calculated from the measurement error (∆ X H , ∆ Y H , ∆ Z H) caused by calibration, that provides a means to evaluate the efficiency of the gesture interaction. The modeling and simulation are implemented to analyze the effectiveness of the multi-objective optimization method proposed in this paper. According to the result of the comparison between the objective function J C S , based on the comfort model C S , and the objective function J P H , based on the measurement precision models ∆ P H , the consistency and the difference can be found due to the variation of the radius r B _ R H O and the center coordinates P B _ R H O x B _ R H O , y B _ R H O , z B _ R H O . The proposed objective function J C P compromises the inconsistency between the objective function J C S and J P H . Therefore, the multi-objective optimization method proposed in this paper is applied to the gesture design to improve the ergonomics and operation efficiency of the gesture, and the effectiveness is verified through usability testing. [ABSTRACT FROM AUTHOR]

In this paper, we study Vicsek polygons and extended Vicsek networks, which are an extension of Vicsek fractal. Our research indices are some Fermat-type indices, including the Fermat eccentricity and the Fermat eccentric distance sum. Fermat-type indices are novel graph invariants with vast potential in research on structure–activity and quantitative structure–property. By the approach of finite pattern, we solve some integrals to gain their asymptotic formulas on Fermat eccentricity and Fermat eccentric distance sum. [ABSTRACT FROM AUTHOR]

Due to good corrosion resistance and high tensile strength, glass fiber–reinforced plastic (GFRP) bolts are widely used in mining operations. However, GFRP bolts are susceptible to blast load damage, so it is important to understand their dynamic mechanical behavior. This experiment constructed a dynamic testing system to simulate the in situ rock bolt dynamic loading conditions. Using strain gauges, the axial load signals at different locations along the bolt were recorded and the corresponding axial stresses were analyzed. Moreover, a numerical model was established to analyze the axial stress distribution along the bolt under dynamic loading. The results showed that the maximum axial stress of GFRP bolt occurs at the bolt collar position and increases approximately linearly as the impact load increases. The axial stress decreased within a short distance from the bolt collar position following approximately an exponential function. In addition, the stronger the mechanical properties of the surrounding rock, the faster the axial stress decreases along the bolt and the greater the increasing rate of the maximum axial stress with an increase of the impact load. The location and increased characteristics of the maximum axial stress in metal and GFRP bolt were similar, but the dynamic load significantly affected the existence range and decreasing rate of axial stress in GFRP bolts than in metal bolts. [ABSTRACT FROM AUTHOR]

In this paper, we transform the classical linear discriminant analysis (LDA) into a smooth difference-of-convex optimization problem. Then, a new difference-of-convex algorithm with extrapolation is introduced and the convergence of the algorithm is established. Finally, for a face recognition problem, the proposed algorithm achieves better classification performance compared with several current algorithms in the literature. [ABSTRACT FROM AUTHOR]

Photocatalytic elimination of antibiotics from the environment and drinking water is of great significance for human health. However, the efficiency of photoremoval of antibiotics such as tetracycline is severely limited by the prompt recombination of electron holes and slow charge migration efficacy. Fabrication of low-dimensional heterojunction composites is an efficient method for shortening charge carrier migration distance and enhancing charge transfer efficiency. Herein, 2D/2D mesoporous WO3/CeO2 laminated Z-scheme heterojunctions were successfully prepared using a two-step hydrothermal process. The mesoporous structure of the composites was proved by nitrogen sorption isotherms, in which sorption-desorption hysteresis was observed. The intimate contact and charge transfer mechanism between WO3 nanoplates and CeO2 nanosheets was investigated using high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy measurements, respectively. Photocatalytic tetracycline degradation efficiency was noticeably promoted by the formation of 2D/2D laminated heterojunctions. The improved photocatalytic activity could be attributed to the formation of Z-scheme laminated heterostructure and 2D morphology favoring spatial charge separation, confirmed by various characterizations. The optimized 5WO3/CeO2 (5 wt.% WO3) composites can degrade more than 99% of tetracycline in 80 min, achieving a peak TC photodegradation efficiency of 0.0482 min−1, which is approximately 3.4 times that of pristine CeO2. A Z-scheme mechanism is proposed for photocatalytic tetracycline by from WO3/CeO2 Z-scheme laminated heterojunctions based on the experimental results. [ABSTRACT FROM AUTHOR]

Pumps as turbines play an important role in micro pumped hydro energy storage (PHES) systems, which are widely applied in remote areas, and their operational safety can be significantly affected by the transient power-off process. The aim is to analyze the unsteady internal flow characteristics and time–frequency characteristics of the pressure fluctuations of the pump as turbine (PAT) after power-off process by using finite volume method (ANSYS CFX) and bidirectional test rig. During the transient process of power failure, internal flow instabilities were revealed by analyzing the flow field and turbulence kinetic energy. The results indicated that the flow field between the blades was extremely unstable during the brake mode. Additionally, the absolute values of the rotational velocity and flow rate were 1.21 and 0.93 times higher than the initial values, respectively, during the runaway mode. The pressure fluctuations were analyzed in the time-frequency domains using the continuous wavelet transform. The main frequency of pressure pulsation at the volute was related to the rotating speed owing to the rotor-stator interaction. This study revealed the transient flow features during the process of mixed-flow pump as turbine failure, which provides a fundamental theory for the safe transient operations of pump as turbine. [ABSTRACT FROM AUTHOR]

Proton exchange membranes (PEMs) with excellent durability and working stability are important for PEM fuel cells with extended service life and enhanced reliability. In this study, highly elastic, healable, and durable electrolyte membranes are fabricated by the complexation of poly(urea–urethane), ionic liquids (ILs), and MXene nanosheets (denoted as PU–IL–MX). The resulting PU–IL–MX electrolyte membranes have a tensile strength of ≈3.86 MPa and a strain at break of ≈281.89%. The PU–IL–MX electrolyte membranes can act as high temperature PEMs to conduct protons under an anhydrous condition of the temperatures above 100 °C. Importantly, the ultrahigh density of hydrogen‐bond‐cross‐linked network renders PU–IL–MX membranes excellent IL retention properties. The membranes can maintain more than ≈98% of their original weight and show no decline of proton conductivity after being placed under highly humid conditions of ≈80 °C and relative humidity of ≈85% for 10 days. Moreover, due to the reversibility of hydrogen bonds, the membranes can heal damage under the working conditions of fuel cells to restore their original mechanical properties, proton conductivities, and cell performances. [ABSTRACT FROM AUTHOR]

Simple Summary: Blue oat mite species mainly include Penthaleus major, P. falcatus, P. tectus, and P. minor. Among them, P. major, P. falcatus and P. tectus are important pest mites on gramineous crops, which often occur in low-temperature and high-humidity environments. These three mites are difficult to distinguish in the field due to their small size and similar shape. Furthermore, they exhibit different resistance to chemical pesticides, making it challenging to control their outbreak. Worryingly, we only saw reports of frequent occurrence of P. major in winter wheat regions in China, and no other species of blue oat mites were found. Understanding the distribution pattern, genetic diversity, and genetic differentiation among populations of blue oat mite species in winter wheat regions of China is essential for developing effective control programs. In this study, we evaluated the distribution of blue oat mites in the major wheat regions in China and assessed the level of genetic diversity and genetic structure of blue oat mites from winter wheat regions of China using mitochondrial cytochrome c oxidase I (COI) sequences. Blue oat mite species, including Penthaleus major and P. tectus, are pests widely distributed across China that cause damage to winter wheat. This study evaluated the genetic diversity of P. major and P. tectus on Triticum hosts collected from 23 geographic locations based on mitochondrial cytochrome c oxidase subunit I (COI) sequences. We identified nine haplotypes in 438 P. major individuals from 21 geographic locations and five haplotypes in 139 P. tectus individuals from 11 geographic locations. Meanwhile, P. major exhibits high values of haplotype diversity (Hd) and nucleotide diversity (Pi) (Hd = 0.534 > 0.5 and Pi = 0.012 > 0.005), representing a large stable population with a long evolutionary history. P. tectus shows low values of Hd and Pi (Hd = 0.112 < 0.5 and Pi = 0 < 0.005), which suggest recent founder events. Moreover, demographic analysis suggested that P. major and P. tectus have not undergone a recent population expansion. The lowest genetic variation was observed in Xiangzhou (XZ-HB), Zaoyang (ZY-HB), Siyang (SY-JS), and Rongxian (RX-SC), with only one species and one haplotype identified in over 30 individuals. Robust genetic differentiation was found in P. major compared to P. tectus, which provides a theoretical basis for the widespread distribution of P. major in China. [ABSTRACT FROM AUTHOR]

Using wearable devices to realize the mining and application of human behavior patterns has become a hotspot in the field of intelligent positioning. Wearable devices provide an analyzable data foundation for indoor spatial distribution and human behavior pattern prediction. The development of the intelligent positioning system based on RSSI has encountered a bottleneck that it is difficult to improve the positioning accuracy. Therefore, some research works started emphasizing location technology based on channel state information (CSI). In this paper, the principle used by Wi-Fi channel state information to realize intelligent positioning is described, the characteristics of CSI are analyzed, and an intelligent positioning algorithm based on CSI is proposed. Specifically, the algorithm first estimates the angle of arrival (AoA) based on the MUSIC algorithm, separates the reflected paths in the multipath components, and accurately estimates the AoA of each path. Second, phase estimation with channel state information is achieved by forming different antenna subarray measurements under the consideration of a subset of antennas and subcarriers. Then, the phase response linear fitting of the data packet CSI is eliminated using the ToF purification algorithm to obtain the corrected phase response and realize the elimination of the STO noise of the channel state information. Finally, the target position is calculated by effectively filtering the reflection path through the likelihood value, and the accurate target positioning function is achieved. The experimental results demonstrate that the intelligent positioning algorithm proposed in this paper can achieve decimeter-level positioning accuracy under the condition of a fixed number of APs, and the average error is better than that of deep learning-based and SVM-based positioning algorithms. In other words, the accuracy of intelligent positioning is improved. [ABSTRACT FROM AUTHOR]

Artificial bone materials are in great need due to a lot of bone injuries. Herein, collagen/nano-hydroxyapatite (Col/nHA, C-H) composite nanospheres were obtained by in-situ mineralization, and poly L-lactic acid/collagen/nano-hydroxyapatite (PLLA/Col/nHA, P-C-H) was further prepared by high-speed shear emulsification method. The interfacial properties and structure between PLLA and nHA are regulated by the adhesive property of Col. The morphology, structure and properties of P-C-H microsphere were characterized in detail by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and simulated degradation of PBS in vitro. The results show that C-H is uniformly distributed in P-C-H microspheres, and a mesoporous material with a "pomegranate" structure and a particle size of 5–30 μm is self-assembled based on C-H multiple composite microspheres. It is beneficial to the sustained-release degradation of P-C-H and the retention/release of Ca2+. The 60-day PBS degradation shows that PLLA delays the degradation of nHA, making the degradation rate of P-C-H basically consist with the human bone healing cycle. The co-culture of P-C-H with MC3T3-E1 cells shows that P-C-H has high biocompatibility and no cytotoxicity. The cell viability is higher than 100 % in 72 h, indicating P-C-H has a proliferation effect on cell growth. Alkaline phosphatase and quantitative real-time PCR test show a positive promotion of P-C-H in cell proliferation and differentiation. The multi-layered P-C-H microspheres have an application potential in bone tissue engineering. [ABSTRACT FROM AUTHOR]

The rapid development of the aviation industry has put forward higher and higher requirements for material properties, and the research on smart material structure has also received widespread attention. Smart materials (e.g., piezoelectric materials, shape memory materials, and giant magnetostrictive materials) have unique physical properties and excellent integration properties, and they perform well as sensors or actuators in the aviation industry, providing a solid material foundation for various intelligent applications in the aviation industry. As a popular smart material, piezoelectric materials have a large number of application research in structural health monitoring, energy harvest, vibration and noise control, damage control, and other fields. As a unique material with deformation ability, shape memory materials have their own outstanding performance in the field of shape control, low-shock release, vibration control, and impact absorption. At the same time, as a material to assist other structures, it also has important applications in the fields of sealing connection and structural self-healing. Giant magnetostrictive material is a representative advanced material, which has unique application advantages in guided wave monitoring, vibration control, energy harvest, and other directions. In addition, giant magnetostrictive materials themselves have high-resolution output, and there are many studies in the direction of high-precision actuators. Some smart materials are summarized and discussed in the above application directions, aiming at providing a reference for the initial development of follow-up related research. [ABSTRACT FROM AUTHOR]

Herein, ultra-low amount Pt is uniformly deposited on the surface of CoFe nanoparticles (NPs) embedded nitrogen-doped carbon nanotubes which are grown directionally on the surface of carbon fiber cloth (Pt–CoFe@NCNT/CFC) using the direct current plasma magnetron sputtering (DC-PMS) technique. The designed electrode exhibits excellent trifunctional catalytic activities towards oxygen reduction reaction (ORR) (in 0.1 M KOH, E 1/2 = 0.807 V; in 0.5 M H 2 SO 4 , E 1/2 = 0.723 V), hydrogen evolution reaction (HER) (in 1 M KOH, η 10 = 17 mV and η 100 = 93 mV; in 0.5 M H 2 SO 4 , η 10 = 42 mV and η 100 = 100.5 mV) and methanol oxidation reaction (MOR) (in 0.5 M H 2 SO 4 + 0.5 M CH 3 OH, peak current density reaches 115 mA mg−1 Pt @1.116 V). It is verified that the DC-PMS technique can greatly improve the utilization efficiency of Pt, so as to reduce the dosage of Pt, and shows better catalytic performance and excellent stability than the commercial Pt/C catalysts. The rich hierarchical heterostructures of the designed electrode can provide more non-noble metal active sites, so as to enhance the catalytic activity and further cut down the consumption of noble metals. Impressively, Pt–CoFe@NCNT/CFC electrode assembled direct methanol fuel cell achieved a remarkable maximum power density of 73.41 mW cm−2 and shows excellent stability. Pt nanoclusters are deposited on the surface of CoFe metal embedded nitrogen-doped carbon nanotubes by DC plasma magnetron sputtering technology, and the designed electrode exhibits excellent trifunctional catalytic activities towards ORR/MOR/HER. [Display omitted] • Pt is uniformly deposited on the surface of CoFe@NCNT/CFC using DC-PMS technique. • Abundant non-noble metal active sites are beneficial to reduce the consumption of Pt. • It provides abundant rivet points for the efficient deposition of Pt. • It shows stable and efficient ORR/MOR/HER multi-functional catalytic performance. • The assembled DMFC exhibits good performance and excellent stability. [ABSTRACT FROM AUTHOR]

Mycotoxin contamination in food poses health hazards to humans. Current methods of controlling mycotoxins still have limitations and more effective approaches are needed. During the past decades of years, variable environmental factors have been tested for their influence on mycotoxin production leading to elucidation of a complex regulatory network involved in mycotoxin biosynthesis. These regulators are putative targets for screening molecules that could inhibit mycotoxin synthesis. Here, we summarize the regulatory mechanisms of hierarchical regulators, including pathway-specific regulators, global regulators and epigenetic regulators, on the production of the most critical mycotoxins (aflatoxins, patulin, citrinin, trichothecenes and fumonisins). Future studies on regulation of mycotoxins will provide valuable knowledge for exploring novel methods to inhibit mycotoxin biosynthesis in a more efficient way. [ABSTRACT FROM AUTHOR]

The aim of this article is an attempt to provide a more credible control mode or a fault-tolerant control strategy for permanent magnet synchronous motor (PMSM) drives when an unexpected failure occurs to the current or position sensor. Considering that, a position sensorless control method that uses only one current sensor is proposed. Different from a traditional position sensorless control scheme that utilizes additional current sensors to obtain information of multiple phase currents, only a single current sensor (SCS) arranged on one of the current branches is included among the whole control circuit. Three-phase currents are reconstructed by sequentially sampling the SCS under specific voltage vectors, and directly employed for motor position estimation. A nonlinear position observer established according to the gradient descent is adopted. Focusing on the special current-acquisition pattern in this article, a step-size optimization method based on golden section search is proposed to minimize position estimation error. The experimental results reveal that the method in this article is comparable to the traditional full-current-sensor method in terms of position estimation, which confirms the fault-tolerant capability as one certain sensor of the control structure malfunctions. [ABSTRACT FROM AUTHOR]

In real world, decision-makers' regret psychology often affects decision outcomes due to uncertain risks. Moreover, decision information may be missing in the process of data acquisitions or data storages. Three-way decision has been widely explored in the risky decision-making area by providing effective strategies to divide objects into three mutually disjoint regions. Existing three-way decision methods in fuzzy incomplete information systems rarely consider the influence of decision-makers' psychological states on decision outcomes. In the current paper, we primarily study a new decision-making method that combines regret theory with three-way decision in fuzzy incomplete information systems. First, a prior probability tolerance dominance relation in a fuzzy incomplete information system is defined to handle a binary relation among evaluation values, and a method to calculate objective weights is designed as well. When an incomplete information system does not contain a fuzzy decision attribute value, we put forward a new method to calculate the decision attribute value of each object in the incomplete information system. Then, integrated utility perception values are obtained by combining with regret theory. Further, a regret theory-based three-way decision method with a priori probability tolerance dominance relation is proposed for fuzzy incomplete information systems. At last, the stability and validity of the presented method are verified via corresponding experimental and comparative analysis of realistic cases. • A new algorithm in a fusion decision system is designed. • A prior probability tolerance dominance relation in an FIIS is defined. • A RT-3WD-PPTDR method is established. • RT in behavior psychology is considered. • The feasibility, stability, and superiority of the constructed method are verified. [ABSTRACT FROM AUTHOR]

The applications of sensors in the aerospace industry are mostly concentrated in the middle and high frequencies, and low-frequency sensors often face the problems of low power and short working bandwidth. A lightweight, thin, high-power, low-frequency broadband transducer based on giant magnetostrictive material is designed. The design and optimization processes of the core components are introduced and analyzed emphatically. The finite element simulation results are validated by the PSV-100 laser vibration meter. Three basic configurations of the work panel are proposed, and the optimal configuration is determined by modal, acoustic, and vibration coupling analyses. Compared with the original configuration, it is found that the lowest resonant frequency of the optimal configuration is reduced by 24.6% and the highest resonant frequency within 2000 Hz is 1744.9 Hz, which is 54.2% higher than that of the original configuration. This greatly improves the vibration power and operating frequency range of the transducer. Then, the honeycomb structure is innovatively applied to the work panel, and it is verified that the honeycomb structure has a great effect on the vibration performance of the work panel. By optimizing the size of the honeycomb structure, it is determined that the honeycomb structure can improve the vibration power of the work panel to its maximum value when the distance between the half-opposite sides of the hexagon is H = 3.5 mm. It can reduce the resonant frequency of the work panel; the lowest resonant frequency is reduced by 12.8%. At the same time, the application of a honeycomb panel structure can reduce the weight of the transducer. [ABSTRACT FROM AUTHOR]

"Lvwen stone" is a yellow-green carbonate jade gemstone. In this study, the gemological characteristics and color genesis of Lvwen stone were investigated using conventional gemological testing methods and analytical techniques, such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–VIS), laser ablation plasma mass spectrometry (LA-ICP-MS), and scanning electron microscopy (SEM). The chemical composition of Lvwen stone is mainly Ca, with lesser amounts of Mg, Mn, Cu, Zn, Fe, and other trace elements. The rare earth element distribution pattern indicates that Lvwen stone is characterized by MREE depletion and a positive Ce anomaly. The mineralogic composition of Lvwen stone is calcite, and trace-element- and crystal-size-induced colors result in its characteristic banded appearance. The white (or light green) bands consist of comparatively coarse calcite crystals (~100 μm) that are oriented perpendicularly to the band plane, accounting for their poor light transmittance. In contrast, the dark green matrix is composed of cryptocrystalline calcite crystals that are uniform in size (~10 μm) and tightly packed, resulting in superior light transmittance. Lvwen stone has a 6A1→4E(4D)d-d intra-ion electronic transition absorption band of Fe3+ at ~380–450 nm and a 2E→2T2(2D)d-d intra-ion electronic transition absorption band of Cu2+ at ~580–780 nm. This indicates that both the intra-ion electronic transitions of Fe3+ and Cu2+ give rise to the unique yellow-green color of the material. Lvwen stone is produced by ultra-high-pressure tectonic fluids in a relatively closed, reducing environment, and the green matrix was formed earlier than the white bands. [ABSTRACT FROM AUTHOR]

Sequential Approximate Optimization (SAO) has been widely used in engineering optimization design problems to improve efficiency. The infilling strategy is one of the critical techniques of the SAO, which is of paramount importance to the surrogate model accuracy and optimization efficiency. In this paper, an adaptive parallel infill strategy for surrogate-based single-objective optimization is proposed within a multi-objective optimization framework to balance exploration and exploitation during the optimization process. Within this method, an inaccurate Pareto Front is adopted to assist the infilling of the sampling points. The proposed SAO method with its adaptive parallel sampling strategy is tested on several numerical test cases and an engineering test case with the optimization results compared to state-of-the-art optimization algorithms. The results show that the proposed SAO with the adaptive parallel sampling strategy possesses excellent performance and better stability. [ABSTRACT FROM AUTHOR]

Epithelial ovarian cancer (EOC) is the main cause of mortality among gynecological malignancies worldwide. Although patients with EOC undergo aggregate treatment, the prognosis is often poor. Peritoneal malignant ascites is a distinguishable clinical feature in EOC patients and plays a pivotal role in tumor progression and recurrence. The mechanisms of the tumor microenvironment (TME) in ascites in the regulation of tumor progression need to be explored. We comprehensively analyzed the transcriptomes of 4680 single cells from five EOC patients (three diagnostic samples and two recurrent samples) derived from Gene Expression Omnibus (GEO) databases. Batch effects between different samples were removed using an unsupervised deep embedding single-cell cluster algorithm. Subcluster analysis identified the different phenotypes of cells. The transition of a malignant cell state was confirmed using pseudotime analysis. The landscape of TME in malignant ascites was profiled during EOC progression. The transformation of epithelial cancer cells into mesenchymal cells was observed to lead to the emergence of related anti-chemotherapy and immune escape phenotypes. We found the activation of multiple biological pathways with the transition of tumor-associated macrophages and fibroblasts, and we identified the infiltration of CD4+CD25+ T regulatory cells in recurrent samples. The cell adhesion molecules mediated by integrin might be associated with the formation of the tumorsphere. Our study provides novel insights into the remodeling of the TME heterogeneity in malignant ascites during EOC progression, which provides evidence for identifying novel therapeutic targets and promotes the development of ovarian cancer treatment. [ABSTRACT FROM AUTHOR]

Network intrusion detection has the problems of large amounts of data, numerous attributes, and different levels of importance for each attribute in detection. However, in random forests, the detection results have large deviations due to the random selection of attributes. Therefore, aiming at the current problems, considering increasing the probability of essential features being selected, a network intrusion detection model based on three-way selected random forest (IDTSRF) is proposed, which integrates three decision branches and random forest. Firstly, according to the characteristics of attributes, it is proposed to evaluate the importance of attributes by combining decision boundary entropy, and using three decision rules to divide attributes; secondly, to keep the randomness of attributes, three attribute random selection rules based on attribute randomness are established, and a certain number of attributes are randomly selected from three candidate fields according to conditions; finally, the training sample set is formed by using autonomous sampling method to select samples and combining three randomly selected attribute sets randomly, and multiple decision trees are trained to form a random forest. The experimental results show that the model has high precision and recall. [ABSTRACT FROM AUTHOR]

Li–CO2 batteries have attracted close attention due to their ability to simultaneously store energy and capture CO2. The development of suitable catalytic cathodes plays a decisive role in promoting the electrochemical performance of Li–CO2 batteries. Herein, an electrocatalytic cathode material based on oxygen-decorated CoP nanosheets is reported. Benefiting from the enhanced electrical conductivity brought about by the presence of P element, the construction of catalytically active sites brought about by the presence of Co–O bonds, and the full exposure of catalytically active sites brought about by the two-dimensional morphology, Li–CO2 batteries exhibit good cycling characteristics (>1000 h) and excellent discharge capacity (13 200 mA h g−1). Density functional theory (DFT) calculations demonstrate that the efficient construction of O–Co–P bonds is the key to improving the performance of electrocatalytic cathodes. This provides an effective reference for the subsequent development of efficient catalytic cathodes. [ABSTRACT FROM AUTHOR]

Flax fibre has been used to reinforce concrete composite, but its dynamic properties have not been thoroughly studied. This study investigates the dynamic splitting tensile properties of plain concrete (PC) confined by flax-fibre-reinforced polymer (FFRP) and glass-fibre-reinforced polymer (GFRP). The dynamic splitting tensile tests were carried out on PC, FFRP-PC, and GFRP-PC cylinder specimens by the high-speed servo-hydraulic machine, with the impact-induced strain rates ranging from 0.1 to 58 s−1. The effect of the FRP confinement, FRP thickness and strain rate on the dynamic splitting tensile behaviour were assessed. The results indicated that similar confinement effectiveness of FFRP and GFRP is observed. The dynamic tensile strength of 1- and 2-layer FFRP-PC increased by 29% and 67%, and the one- and two-layer GFRP-PC increased by 32% and 84%, respectively. FFRP-PC and GFRP-PC cylinders showed less sensitivity to the strain rate compared with PC. The empirical relationship between the tensile DIF and strain rate for PC, FFRP-PC and GFRP-PC was proposed based on experimental data. The proposed model was developed to predict the dynamic splitting tensile strength. The results suggested the potential of FFRP composites applied into concrete structures under extreme dynamic loadings. [ABSTRACT FROM AUTHOR]

In this paper, high thermal conductivity PcBN composites with Al–Si as binder and diamond as additive were prepared by high temperature and high pressure (HTHP) sintering at 5 GPa and 1500 °C. The effects of diamond content on the phase composition, microstructure, density, thermal conductivity, and volume resistivity of PcBN composites were characterized and studied. With the increase of diamond content, the thermal conductivity of PcBN samples increases first and then decreases. When the diamond content is 4 wt%, the thermal conductivity of PcBN composites is the highest, reaching 146.3 W m−1K−1, which is 20.2% higher than the thermal conductivity without diamond. At the same time, the reduction of the residual silicon liquid phase in the sintered body also increases the volume resistivity of the composites. With the increase of diamond content, the volume resistivity of PcBN composites also increases. The volume resistivity of PcBN composite with diamond content of 16 wt% reaches 1.25 * 1010 Ω·cm. [ABSTRACT FROM AUTHOR]

A facile hydrothermal and freeze‐drying approach was employed to prepare N, B co‐doped graphene gel (N/BGR). Positively charged [BMIm][BF4] ionic liquid as N/B source and negatively charged graphene oxide (GO) as graphene precursor are capable of combining and self‐assembly by electrostatic force. The high doped concentrations of N and B elements are 8.16 at% and 6.31 at% (total 14.47 at%). The N/BGR was fabricated as electrode material in the three‐electrode system. The as‐prepared N/BGR‐2 electrode could achieve a specific capacitance of 133.6 F/g at 0.5 A/g. The N/BGR electrode presented enhanced capacitance performance. Compared with the specific capacitance of pure GR at the same current density of 0.5 A/g, the specific capacitances of N/BGR‐2 and N/BGR‐1 have increased by 68.5 % and 49.4 %. The enhanced capacitance of N and B co‐doped graphene could be attributed to the promotion of rapid electron migration and charge transfer and production of redox active sites that provide pseudocapacitance. In addition, N/BGR‐2 electrode exhibits good cycling durability with the capacity retention of 93.2 %% after 1500 cycles at a high current density of 10 A/g. Those provide a high co‐doped content fabrication strategy for high‐performance supercapacitors carbon‐based electrode materials. [ABSTRACT FROM AUTHOR]

Let M be a trans-Sasakian 3-manifold such that the Ricci curvature of the structure vector field vanishes. In this paper, it is proved that if M is compact, then it is homothetic to a cosymplectic manifold. Without the compactness assumption, we prove that M is locally isometric to the product of ℝ and a Kahler surface of constant curvature if the Ricci operator of M is of Codazzi type or cyclic parallel. We classify trans-Sasakian 3-manifolds with Killing type Ricci tensors. We construct some concrete examples to illustrate the above theorems. [ABSTRACT FROM AUTHOR]

Introduction: To analyze and summarize the orthopaedic effect and application experience of the Wang procedure in the treatment of pectus excavatum in paediatric patients. Methods: The clinical data of 256 children ranging from 0.83~14 years (4.89±2.83 years) who underwent the Wang procedure for pectus excavatum from January 2017 to September 2020 in our hospital were analyzed retrospectively. A 1~2-cm incision was made in front of the xiphoid, and a tunnel was constructed on the deep surface of the thoracic cage. Steel wires were inserted through the bilateral costal arch and the lower sternum, and a steel bar was placed in the tunnel. The wires were pulled taut and fixed to the bar, and the incision was sutured. Results: All the procedures were performed using one steel bar. The range of the procedure duration, the intra-operative bleeding volume, and the hospitalization stays of the patients were 18 to 45 (24.02±4.89) minutes, one to ten (2.16±1.68) mL, and three to nine days (5.71±1.35 days) respectively. Post-operative pneumothorax occurred in three cases without other complications. All the cases received follow-up for one to 45 months after discharge, during which six cases experienced poor wound healing, removed steel plate in 82 cases, and three cases of pectus excavatum recurrence. Conclusions: The Wang procedure is a good option for treating pectus excavatum, secondary pectus excavatum, or recurrent pectus excavatum in paediatric patients. [ABSTRACT FROM AUTHOR]

The ingenious design of high-performance tin-based lithium-ion batteries (LIBs) is challenging due to their poor conductivity and drastic volume change during continuous lithiation/delithiation cycles. Herein, we present a strategy to confine heterostructured SnSe2–SnO2 nanoparticles into macroscopic nitrogen-doped carbon microbelts (SnSe2–SnO2@NC) as anode materials for LIBs. The composites exhibit an excellent specific capacity of 436.3 mA h g−1 even at 20 A g−1 and an ultrastable specific capacity of 632.7 mA h g−1 after 2800 cycles at 5 A g−1. Density Functional Theory (DFT) calculations reveal that metallic SnSe2–SnO2 heterostructures endow the lithium atoms at the interface with high adsorption energy, which promotes the anchoring of Li atoms, and enhances the electrical conductivity of the anode materials. This demonstrates the superior Li+ storage performance of the SnSe2–SnO2@NC microbelts as anode materials. [ABSTRACT FROM AUTHOR]

In recent decades, surrogate-based optimization (SBO) has been developed to replace costly models with cheap surrogates to improve efficiency. In this article, an adaptive parallel infill strategy is proposed to balance exploration and exploitation over the design space during the optimization process of SBO. Within this method, an inaccurate search strategy is adopted to optimize the surrogate models, thereby helping to locate the exploitation point. An elite archive is exploited to store superior sampling points for batch sampling, while a customized batch size determination strategy is introduced. The proposed SBO method with its adaptive parallel sampling strategy is tested on six unconstrained and five constrained analytical cases with the optimization results compared to state-of-the-art optimization algorithms. The optimization of a 582-bar tower truss system is also performed and utilized to verify the proposed SBO method. The proposed SBO with the adaptive parallel sampling strategy shows excellent performance and better stability. [ABSTRACT FROM AUTHOR]

With global warming and the depletion of fossil energy sources, renewable energy is gradually replacing non-renewable energy as the main energy in the future. As one of the fastest growing renewable energy sources, the safety and reliability of wind energy have been paid more and more attention. The size of modern wind turbines is becoming larger and larger. As the main component of wind turbines to capture energy, the blade is often damaged by various complex environments and irregular loads. Therefore, the health monitoring and damage identification of wind turbine blades have become a main research focus. At present, in addition to the overview of various detection methods of wind turbine blades, there is a lack of comprehensive classifications and overviews of the main damage types, damage-generation mechanisms, and basic principles of the damage-detection technology of wind turbine blades. In this paper, firstly, the common fault types of wind turbine blades, such as trailing edge cracking, lightning strike, leading edge corrosion pollution, icing, and delamination, as well as their generation mechanism, are comprehensively analyzed. Then, the basic principles and the latest research progress of the current main detection technologies, such as vision, ultrasonic, thermal imaging, vibration, acoustic emission, and so on, are comprehensively reviewed. The advantages and limitations of the various detection technologies for practical application are summarized. Finally, through a comparative analysis of the various damage-detection technologies, we try to find potential future research directions, and draw conclusions. This paper will provide a reference for understanding the mechanism behind the main damage types and the damage-detection methods of wind turbine blades. It has important reference value for further promoting practical research of wind turbine blade damage-detection technology and grasping this research direction. [ABSTRACT FROM AUTHOR]

As a burgeoning surface finishing process, laser polishing (LP) introduces some undesired surface structures, limiting access to better laser-polished surfaces. Considering this, the paper proposes a novel hybrid processing method, ultrasonic vibration-assisted laser polishing (UVLP). Horizontal ultrasonic vibration, perpendicular to the laser scanning direction, is imposed on the workpiece, which promotes homogenized melt distribution in the melting pool, contributing to the polished surface flatness. Bulge, a typical surface structure formed in LP, serves as the verification vehicle for the effect of ultrasonic vibration here. In this investigation, comparative experiments were performed on 304 stainless steels to demonstrate the regulation phenomenon of ultrasonic vibration on the bulge formation. Subsequently, the corresponding numerical model was developed to explore the acting mechanisms of ultrasound from the thermal and hydrodynamic fields. The model also optimized the coupling method of volume expansion to better capture the change in melting pool volume during the polishing process, especially during the cooling phase. The results indicated that the forced melt oscillations are the dominant mechanism to uniformize the metallic materials distribution, regulating the bulge formed along the polished track. The degraded melt flow pattern, a simple harmonic oscillation, reached similar results. Furthermore, the developed model verified its effectiveness through surface flatness, melting pool dimensions, and microhardness. • A new hybrid processing method, ultrasonic vibration-assisted laser polishing (UVLP), is proposed. • The regulation phenomenon of ultrasonic vibration on the bulge formation is visualized. • The acting mechanisms of ultrasonic vibrations in UVLP are analyzed theoretically and experimentally. • A UVLP model is developed and its effectiveness is verified. • The coupling method for volume expansion is optimized. [ABSTRACT FROM AUTHOR]

The online-to-offline (O2O) meal delivery mode in which takeout meals are ordered online and delivered offline is recently emerging. The fast delivery of huge meal orders for time-sensitive customers imposes great challenges on O2O meal delivery platforms. This study establishes a two-stage solution for meal delivery routing optimization with the objective of maximizing time-sensitive customer satisfaction. In the first stage, a large number of meal orders are hierarchically classified and merged into delivery bundles based on the nearest pickup location rule by applying the hierarchical agglomerative clustering (HAC) algorithm, to increase fast meal delivery efficiency. In the second stage, a genetic algorithm (GA) is applied to solve the cluster-based delivery routing optimization model to find an optimal delivery route for meal orders in each delivery bundle. The numerical simulation results verify that the two-stage routing optimization solution is effective to schedule timely meal delivery and improve customer time satisfaction. The comparison of the results indicates the superiority of the proposed two-stage solution with HAC and GA on customer satisfaction while ensuring the delivery of all orders within 60 minutes. The sensitivity analysis shows the impact of time-sensitive customer heterogeneity on meal delivery satisfaction. This research has significant managerial insights for fast delivery services of O2O meal delivery platforms. [ABSTRACT FROM AUTHOR]