Search

Soil microbial extracellular enzymes play crucial roles in soil carbon and nutrient cycling by catalyzing soil biochemical processes. However, the activity and stoichiometry of enzymes involved in the carbon, nitrogen, and phosphorus cycles in the environment with the highest density of wild giant pandas on the southern slopes of the Qinling Mountains is unknown. We have established eight research areas at an elevation of 1090–2621 m. The β‐1,4‐glucosidase (BG), β‐1,4‐N‐acetylglucosaminidase (NAG), and acid phosphatase (APase) in soil samples were measured. We used redundancy analysis and structural equation model to evaluate the driving factors of metabolic restriction of soil microorganisms along the elevational gradient, and four models were used to cross‐evaluate the nutrient restriction status of soil microorganisms. The results showed that most soil physiochemical properties, soil microbial biomass, and microbial extracellular enzymes exhibited a hump‐shaped trend with increasing elevation. Elevation indirectly affected soil enzyme activity and stoichiometry by C, N, and P status. Microorganisms are limited by C at lower and higher elevations but limited by N at medium elevations. These results could help strengthen the conservation and management of the wild panda's natural habitat. Soil nutrient and elevation change are the main influence factors of soil enzyme activity and stoichiometry.The soil microorganisms in the Foping Protected area are limited by P, limited by N at middle and high elevations.Soil microorganisms are less restricted by C in middle elevations than at other elevations.Soil microorganisms to maintain a stable elemental composition of biomass are weak in the southern slope of Qinling.

The Chinese standard method of GB/T 4000–2017 was unable to accurately measure the coke thermal properties in the large blast furnace. Therefore, the coke compressive strength (CCS) test at a high temperature was designed to examine the coke thermal properties. Then, the large-scale coke model (sp2C17421sp3C6579) was established. After, the ReaxFF molecular dynamics simulations were implemented to mimic the coke solution loss (CSL) and the CCS at the high temperature. It was found that the adsorption energy and the diffusion energy of micropores were greater than those of mesopores and macropores, indicating that the CSL reaction mainly happened in the coke micropore. It was discovered that the CSL reaction mechanism was the sp3C oxidization mechanism with the transient state of ketene structure. And, it was detected that the CCS process was divided into the plastic deformation, the instantaneous fracture and the elastic deformation and yield, which was caused by the local reconstruction, the overall folding and the center stretching of carbon layer, respectively. By comparing simulated results with experiments, it was proved that obtained mechanisms were valid. The proposed experimental and simulated methods provided a novel method to measure and understand the coke thermal properties.

Background: Upper extremity (UE) dynamic balance is a significant physical fitness ability, which includes high-level neuromuscular proprioception, joint mobility, force, and coordination. The evaluation methods of UE dynamic balance are insufficient and lack experimental support. The Star Excursion Balance Test (SEBT) is a reliable assessment of dynamic balance and injury risk of the lower extremity.Hypothesis: The UE-SEBT is a reliable and reproducible approach for evaluating dynamic balance of UEs.Study Design: Observational study.Level of Evidence: Level 4.Methods: This cross-sectional study recruited 65 healthy adults. All participants were required to complete UE-SEBT, UE Y-balance test (UE-YBT), maximal voluntary isometric contraction (MVIC) of UE, closed kinetic chain UE stability test (CKCUEST), trunk flexor endurance test (TFET), trunk extensor endurance test (TEET), and lateral trunk endurance test (LTET). Intra- and inter-rater reliability and the correlation of UE-SEBT with other outcomes were measured.Results: Among the participants, the intra- and interoperator reliability of UE-SEBT in all directions and composite score achieved a moderate-to-excellent (intraclass correlation coefficients [ICC], 0.729-0.946) reliability. For validity, the UE-SEBT had a moderate to very strong correlation with UE-YBT (r= 0.315-0.755, P< 0.01) and a strong correlation with CKCUEST (r= 0.4-0.67, P< 0.01). Furthermore, the UE-SEBT performance showed weak-to-strong correlations with MVIC (r= 0.26-0.43, P< 0.05). UE-SEBT was also correlated with LTET, TEET, and TFET to varying degrees.Conclusion: UE-SEBT has good reliability and validity to assess UE dynamic balance compared with other tests.Clinical Relevance: UE-SEBT can be used as a clinical assessment method to evaluate UE dynamic balance and injury prevention.

A novel three-dimensional numerical model is proposed to investigate the effect of tool eccentricity on the coupled thermal and material flow characteristics in friction stir welding (FSW) process. An asymmetrical boundary condition at the tool−workpiece interface, and the dynamic mesh technique are both employed for the consideration of the tool eccentricity during tool rotating. It is found that tool eccentricity induces the periodical variation of the heat densities both at the tool−workpiece interface and inside the shear layer, but the fluctuation amplitudes of the heat density variations are limited. However, it is demonstrated that tool eccentricity results in significant variation of the material flow behavior in one tool rotating period. Moreover, the material velocity variation at the retreating side is particularly important for the formation of the periodic characteristics in FSW. The modeling result is found to be in good agreement with the experimental one.

Due to signal shielding caused by building structures, conventional mature positioning technologies such as the Global Positioning System (GPS) are only suitable for outdoor navigation and detection. However, there are many scenarios that urgently require high-precision indoor positioning technologies, such as indoor wireless optical communications (OWCs), navigation in large buildings, and warehouse management. Here, we proposed a millimeter-precision indoor positioning technology based on metalens-integrated camera, which determines the position of the device through imaging of beacon LEDs. Thanks to the wide-angle imaging design of our metalens, the camera can accurately capture images of beacon LEDs even when it is situated in distant corner locations. Consequently, our localization scheme achieves millimeter-level positioning accuracy across majority of wide-angle (∼120°) indoor area. Compared to traditional positioning schemes by photodiode (PD), our imaging-based approach demonstrates superior resistance to interference, thereby safeguarding positioning precision from the external signals influence. Furthermore, the compact dimensions and high performances of the positioning device make it suitable for integration into highly portable devices, such as smartphones and drones, revealing its broad potential applications in the future.

Joining dissimilar Mg/Cu alloys was still an intractable problem because of the excessive intermetallic compounds (IMCs) and poor mechanical properties using conventional welding methods. In the present study, friction stir welding was employed for the butt joining of dissimilar AZ31B Mg-alloy and T2 pure Cu plates. Defect-free Mg/Cu joints were obtained with Mg-RS and Cu-AS configuration, at a welding speed of 50 mm/min and tool rotating speeds of 325 r/min, 625 r/min and 925 r/min. At the joining interface, both Mg2Cu and MgCu2IMC phases were observed, with a clear, uniform and continuous IMCs layer composed of two sub-layers, layer-A of Mg + Mg2Cu and layer-B of Mg2Cu + MgCu2. The maximum ultimate tensile strength of the Mg/Cu friction stir welding joint reached 130 MPa at 925 r/min due to enhanced mechanical interlocking between Mg and Cu, as well as sufficient metallurgical bonding at the joining interface with an IMCs layer thickness in the range of 1.0–2.0 μm.

This article studies the impact of strain relief loops on RF-induced heating of active implantable medical devices (AIMDs) during magnetic resonance imaging (MRI) scans at 1.5 T. Two commercially available AIMDs, a 40-cm lead length peripheral nerve stimulator (PNS) and a 60-cm lead length spinal cord stimulator (SCS), were utilized. In the in vitro study, lead-tip heating was calculated using the transfer function (TF) method and compared to direct measurement results for strain relief loops at various locations. In the human model analysis, RF-induced heating along six PNS and two SCS trajectories within the Duke, Ella, and FATS models was evaluated for strain relief loops positioned at various locations along the implantation trajectories. From the in vitro study, we can see up to a 48.3% reduction in the overall lead-tip heating. Inappropriate placement may result in doubled temperature rises. Significant temperature rise variation (up to 9°C) is observed with loop position, loop diameter, number of turns, and patient landmark. Differentiation of cumulative summation analysis is necessary to comprehend the strain relief loop's effect on RF-induced heating. The findings suggest that strategically placing the loop can effectively mitigate RF-induced heating for AIMDs exposed to 1.5-T MR environments.

This article explores the influence of patient postures on radiofrequency induced heating in active implantable medical devices (AIMDs) within a 1.5T magnetic resonance imaging system. Employing the transfer function method, the study assesses RF-induced heating for AIMDs in four different postures. Three AIMD types deep brain stimulation (DBS), cardiac rhythm management (CRM), and sacral neuromodulation (SNM)] are studied across three human models (Duke, Ella, and Fats) at four imaging landmarks under two RF exposure levels: B1+ and specific absorption rate (SAR) restrictions. When comparing temperature rises observed in various postures to those obtained from the typical/standard posture, it was noted that temperature rises can vary significantly. Specifically, temperature rises were found to have variations of up to 82% and 96% for prone and supine arm loop postures, respectively, while remaining within 27% for leg and trunk arm loop postures. Across DBS, CRM, and SNM systems, averaged temperature rises can vary up to 96%, 96%, and 89%, respectively. Noteworthy landmark-specific variations are observed, with changes of up to 43%, 33%, 95%, and 96% for head, cardiac, abdomen, and hip scans. The study underscores the significant impact of patient posture on AIMD heating, emphasizing the necessity for evaluations under diverse conditions.

Data-driven approaches have been widely used in various fields, and there is a growing interest in using machine learning (ML) to discover potential materials to save trial-and-error time and cost. In this work, an ML framework based on random forest (RF) classification method and limited data is built to explore the relationship between dielectric properties and composites microstructure, and composites with desired dielectric properties are designed rationally. Through feeding physical, geometric, and distributional parameters of nanofillers as fingerprints into the RF algorithm, the linkage between the dielectric properties, including breakdown strength, permittivity, energy density, and the features, is established. The resulting ML model is used to predict the dielectric properties of 100 000 of randomly generated candidate composites, and some suggestions for microstructure design of high energy density composites are presented. The results indicate that the tradeoff between permittivity and breakdown strength can be achieved through the interplay of physical and distributional characteristics, which provides a route to effectively enhance the energy density, and the coordination between nanofiller and matrix is also crucial to increase the energy density of composites, among which a significant contrast in the bandgap between the filler and matrix is more preferred.

Al–Li alloy has been widely used in the manufacture of aerospace aircraft structural parts due to its high specific strength and excellent comprehensive performance. Friction stir welding (FSW), as a solid-state joining technique, generates comparatively lower heat generation in contrast to fusion welding. However, even with this reduced heat input, the welded joints of 2195 Al–Li alloy still exhibit noticeable thermal softening. FSW is very sensitive to welding heat input, and the thermal cycle of high peak temperature coarsens the grain in the weld zone, thereby reducing joint properties. To overcome these problems, external cooling can be applied to reduce peak temperature and increase cooling speed, improving the performance of FSW joints. In order to study the mechanism of external cooling on the microstructure evolution of joints, this work established a multi-scale simulation of splat cooling assisted friction stir welding (SCaFSW) of 2195 Al–Li alloy. The temperature change and material deformation data in SCaFSW were calculated in the macroscopic finite element model and used for further Monte Carlo microstructure evolution simulation, and compared with the conventional FSW process. Results reveal that the splat cooling significantly reduces the area of the high temperature region of the workpiece, decreasing the temperature at the same location 10 mm behind the tool by approximately 50 °C compared to FSW. While the local temperature field around the tool pin is not affected by the splat cooling, which mainly accelerates the cooling rate of the welded joint and reduces the plastic strain. In addition, the dislocation density in the weld nugget zone (WNZ) of SCaFSW joint is higher than that in conventional FSW, which promotes the process of grain nucleation and finally refines the grain in the WNZ. The simulated average grain size and thermal cycling results are in good agreement with the experimental results.

A unified constitutive model is established to predict the plastic flow behavior of face-centered cubic (FCC) metal in the ultrasonic vibration (UV) assisted forming. The model describes UV softening behavior based on the dislocation dynamics in the UV combined with the stress superposition mechanism. The interaction among dislocation density, grain size and UV is considered, and the residual behavior of UV-assisted forming can be predicted by modelling with dislocation density and grain size as internal state variables. UV-assisted compression tests were performed on oxygen-free high-thermal conductivity (OFHC) copper to verify the predictive ability of the model. The results show that OFHC copper exhibits obvious softening behavior and residual softening behavior in the UV. The model prediction is in good agreement with the experimental result, which effectively captures the softening effect and residual effect of copper.

Century eggs (also known as pídàn) are a widely used preserved food product in Taiwanese cuisine. Due to their peculiar appearance, pungent odor, and unusual texture, several consumers have raised concerns. Actually, some metallic additives are employed to control the quality of gelation of protein during the production of century eggs. Therefore, a method involving microwave plasma‐atomic emission spectrometer and microwave‐assisted digestion was proposed in this study. In addition, to clarify distribution information of metallic additives in century eggs, detailed analyses based on the egg structure were adopted. The linearities for Fe and Zn were obtained in the range of 0.1–5, and 0.02–1 mg L−1for Cu and Pb. The method detection limits for test metals were 0.06–0.036 mg L−1. The measured values for the RM EGGS‐1 sample agreed reasonably well with the reference values, demonstrating that the developed method is practical for routine analysis with lower instrument procurement/running cost. The analytical results for century eggs collected from local markets revealed diverse distributions of metal ions in different parts. Remarkably, this method can readily identify the metallic additives used during the production processes even in the presence of complicated matrices. Because metallic additives are widely employed to control protein gelation during the production of century eggs, quantitative information regarding these additives is crucial for ensuring the safe consumption of century eggs. The developed methodology can not only identify such additives during the production processes but also clearly indicate the distribution of metal ions in century eggs.

Cancer remains one of the leading causes of mortality worldwide, leading to increased interest in utilizing immunotherapy strategies for better cancer treatments. In the past decade, CD103+T cells have been associated with better clinical prognosis in patients with cancer. However, the specific immune mechanisms contributing toward CD103-mediated protective immunity remain unclear. Here, we show an unexpected and transient CD61 expression, which is paired with CD103 at the synaptic microclusters of T cells. CD61 colocalization with the T cell antigen receptor further modulates downstream T cell antigen receptor signaling, improving antitumor cytotoxicity and promoting physiological control of tumor growth. Clinically, the presence of CD61+tumor-infiltrating T lymphocytes is associated with improved clinical outcomes, mediated through enhanced effector functions and phenotype with limited evidence of cellular exhaustion. In conclusion, this study identified an unconventional and transient CD61 expression and pairing with CD103 on human immune cells, which potentiates a new target for immune-based cellular therapies.

Wire-arc directed energy deposition (DED) of Al–Zn–Mg–Cu alloy faced a tough challenge because of the occurrence of crack and pore defects caused by the high content of alloying elements. Three cold metal transfer (CMT) arc modes were studied to fabricate Al–Zn–Mg–Cu alloy components via the wire-arc DED process, with the aim of optimizing the deposition process and revealing the action mechanism of arc mode on the microstructure and mechanical properties. The effect of the CMT arc mode on the forming accuracy and arc/droplet behaviors was investigated with the assistance of the microscope and high-speed camera. The characteristics of grain morphology, crystallographic texture, and precipitated phase were quantitatively analyzed. The results show that the forming accuracies of deposited samples degenerate when using CMT and CMT pulse modes due to abnormal electrical waveforms and overflow/curve phenomenon. The finest grain size is realized under CMT advance mode because of its induced stirring effect on the molten pool, expanded constitutional supercooling zones, and extremely low heat input. The continuous and coarse precipitated phases in CMT and CMT pulse modes are transferred into dispersive ones in CMT advance mode. Moreover, the quantity and size of pores are also reduced in CMT advance mode. The combined action of microstructure optimization and defect reduction is conducive to improving the mechanical properties. Finally, the preferable ultimate tensile strength (∼278.15 MPa) and top elongation (∼6.50 %) of as-deposited Al–Zn–Mg–Cu alloy are achieved.

Permafrost is degrading globally, particularly those with low thermal stability on the Qinghai‒Tibet Plateau, owing to climate change. However, the inadequacy of direct research on permafrost degradation based on in-situmonitoring limits the prediction of permafrost degradation and engineering practices. This study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai‒Tibet Plateau from 2006 to 2021. The results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom directions. The rate of permafrost degradation from the top down and bottom up increase during the degradation process, but the increase of the former is more drastic after the formation of thawed interlayer. Additionally, the construction of the Qinghai‒Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer, particularly after through talik formation under the embankment. The findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more effective. When evaluating the thermal impact of projects in warm permafrost regions, special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

The 3d transition metal-catalyzed enantioconvergent radical cross-coupling provides a powerful tool for chiral molecule synthesis. In the classic mechanism, the bond formation relies on the interaction between nucleophile-sequestered metal complexes and radicals, limiting the nucleophile scope to sterically uncongested ones. The coupling of sterically congested nucleophiles poses a significant challenge due to difficulties in transmetalation, restricting the reaction generality. Here, we describe a probable outer-sphere nucleophilic attack mechanism that circumvents the challenging transmetalation associated with sterically congested nucleophiles. This strategy enables a general copper-catalyzed enantioconvergent radical N-alkylation of aromatic amines with secondary/tertiary alkyl halides and exhibits catalyst-controlled stereoselectivity. It accommodates diverse aromatic amines, especially bulky secondary and primary ones to deliver value-added chiral amines (>110 examples). It is expected to inspire the coupling of more nucleophiles, particularly challenging sterically congested ones, and accelerate reaction generality.

The permeability and selectivity of biological and artificial ion channels correlate with the specific hydration structure of single ions. However, fundamental understanding of the effect of ion–ion interaction remains elusive. Here, via non-contact atomic force microscopy measurements, we demonstrate that hydrated alkali metal cations (Na+and K+) at charged surfaces could come into close contact with each other through partial dehydration and water rearrangement processes, forming one-dimensional chain structures. We prove that the interplay at the nanoscale between the water–ion and water–water interaction can lead to an effective ion–ion attraction overcoming the ionic Coulomb repulsion. The tendency for different ions to become closely packed follows the sequence K+> Na+> Li+, which is attributed to their different dehydration energies and charge densities. This work highlights the key role of water molecules in prompting close packing and concerted movement of ions at charged surfaces, which may provide new insights into the mechanism of ion transport under atomic confinement.

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P< 5 × 10−8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.

The mixing of powders is a highly relevant field under additive manufacturing, however, it has attracted limited interest to date. The in-situ mixing of various powders remains a significant challenge. This paper proposes a new method utilizing a static mixer for the in-situ mixing of multiple powders through the laser-based directed energy deposition (DED) of functionally graded materials. Firstly, a powder-mixing experimental platform was established; WC and 316L powders were selected for the mixing experiments. Secondly, scanning electron microscopy, energy dispersive spectroscopy, and image processing were used to visually evaluate the homogeneity and proportion of the in-situ mixed powder. Furthermore, powder-mixing simulations were conducted to determine the powder-mixing mechanism. In the simulations, a powder carrier gas flow field and particle mixing were employed. Finally, a WC/316L metal matrix composite sample was produced using laser-based DED to verify the application potential of the static mixer. It was found that the static mixer could adjust the powder ratio online, and a response time of 1–2 s should be considered when adjusting the ratio of the mixed powder. A feasible approach for in-situ powder mixing for laser-based DED was demonstrated and investigated, creating the basis for functionally graded materials.

Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that can bind to several receptors and mediate distinct molecular pathways in various cell settings. Changing levels of LECT2 have been implicated in multiple human disease states, including cancers. Here, we have demonstrated reduced serum levels of LECT2 in patients with epithelial ovarian cancer (EOC) and down-regulated circulating Lect2 as the disease progresses in a syngeneic mouse ID8 EOC model. Using the murine EOC model, we discovered that loss of Lect2 promotes EOC progression by modulating both tumor cells and the tumor microenvironment. Lect2 inhibited EOC cells’ invasive phenotype and suppressed EOC’s transcoelomic metastasis by targeting c-Met signaling. In addition, Lect2 downregulation induced the accumulation and activation of myeloid-derived suppressor cells (MDSCs). This fostered an immunosuppressive microenvironment in EOC by inhibiting T-cell activation and skewing macrophages toward an M2 phenotype. The therapeutic efficacy of programmed cell death-1 (PD-1)/PD-L1 pathway blockade for the ID8 model was significantly hindered. Overall, our data highlight multiple functions of Lect2 during EOC progression and reveal a rationale for synergistic immunotherapeutic strategies by targeting Lect2.

Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace (BF) ironmaking. Essentially, BF is a high-temperature moving bed reactor, where complex physical transformations coupled with complicated reactions occur. This makes it challenging to investigate the factors determining BF performance with the conventional method. A multi-physical field coupling mathematical model of BF was thus developed to describe its mass and heat transfer as well as its intrinsic reactions. Then, the proposed model was validated with the production data. Under coupling conditions, influences of dominating reactions on BF performance (temperature distribution, gas distribution, iron formation reaction, and direct reduction degree) were revealed. The results indicated that coke combustion, indirect reduction, and direct reduction of iron ore mainly took place nearby the shaft tuyere, cohesive zone, and dripping zone, respectively. Besides, the rate of coke solution loss reaction was increased with the rising coke porosity in the cohesive zone. Considering the effect of coke porosity on the efficiency and stability of BF, the coke porosity of 0.42 was regarded as a reasonable value.

Coastal wetlands contribute to the mitigation of climate change through the sequestration of “blue carbon”. Microbial necromass, lignin, and glycoproteins (i.e., glomalin-related soil proteins (GRSP)), as important components of soil organic carbon (SOC), are sensitive to environmental change. However, their contributions to blue carbon formation and the underlying factors remain largely unresolved. To address this paucity of knowledge, we investigated their contributions to blue carbon formation along a salinity gradient in coastal marshes. Our results revealed decreasing contributions of microbial necromass and lignin to blue carbon as the salinity increased, while GRSP showed an opposite trend. Using random forest models, we showed that their contributions to SOC were dependent on microbial biomass and resource stoichiometry. In N-limited saline soils, contributions of microbial necromass to SOC decreased due to increased N-acquisition enzyme activity. Decreases in lignin contributions were linked to reduced mineral protection offered by short-range-ordered Fe (FeSRO). Partial least-squares path modeling (PLS-PM) further indicated that GRSP could increase microbial necromass and lignin formation by enhancing mineral protection. Our findings have implications for improving the accumulation of refractory and mineral-bound organic matter in coastal wetlands, considering the current scenario of heightened nutrient discharge and sea-level rise.

Although adolescents’ family socioeconomic contexts have been widely investigated, their conventional indicators neglect human adaptability, are segmented and difficult to modify, and show inconsistent effects on outcomes and across sex subgroups. Financial resilience is recently proposed as a more actionable and sustainable financial capability to cope with and adapt to emergencies and adversities, while its multidimensionality and impacts on adolescents have yet to be validated. This study utilizes developmental resilience theory and family financial socialization theory as foundations to establish its arguments. Factor analysis and structural equation modeling were performed to analyze data from the China Family Panel Studies. The four-dimensional structure of financial resilience was explored, comprising financial access, financial literacy, financial behavior, and social capital. The overall financial resilience index and its dimensions showed significant associations with psychological and school outcomes among adolescent boys and girls after controlling socioeconomic and demographic covariates. This study indicates that financial resilience might be a family socioeconomic determinant of adolescent outcomes, although its effects are not strong. Empirical evidence also suggests that financial resilience may have intergenerational effects, comprehensive socialization influences, and future-oriented characteristics among the adolescent sample, thus enriching its theoretical foundations. Meanwhile, nonsignificant results highlight the importance of considering the multidimensionality, cultural and situational contexts, population heterogeneities, developmental stages, and underlying mechanisms of financial resilience. This study could provide capability-based insights for understanding socioeconomic inequality, adolescent development, and family process. Practitioners may incorporate financial resilience into traditional socioeconomic interventions and human services.

A magnetic generating device was proposed to regulate the transverse and backward flow of weld pool for high-speed gas metal arc welding (GMAW). Compound external magnetic field (EMF) was simulated to verify the feasibility of designed magnetic generating device. The highest welding speed with good weld bead appearance was 1.7 m/min with the wire feed speed of 9.0 m/min when compound EMF was applied. The effect of the compound EMF on the arc and droplet motion was studied by image acquisition system. The suppression mechanism of the compound EMF on the undercut defect of high-speed GMAW was analyzed. The mechanism of the influence of the applied compound EMF on different welding speeds and welding currents was studied by the application of the compound EMF-assisted welding process, and low-cost, high-quality, and high-speed welding technology was realized.

Ice surfaces are closely relevant to many physical and chemical properties, such as melting, freezing, friction, gas uptake and atmospheric reaction1–8. Despite extensive experimental and theoretical investigations9–17, the exact atomic structures of ice interfaces remain elusive owing to the vulnerable hydrogen-bonding network and the complicated premelting process. Here we realize atomic-resolution imaging of the basal (0001) surface structure of hexagonal water ice (ice Ih) by using qPlus-based cryogenic atomic force microscopy with a carbon monoxide-functionalized tip. We find that the crystalline ice-Ih surface consists of mixed Ih- and cubic (Ic)-stacking nanodomains, forming 19×19periodic superstructures. Density functional theory reveals that this reconstructed surface is stabilized over the ideal ice surface mainly by minimizing the electrostatic repulsion between dangling OH bonds. Moreover, we observe that the ice surface gradually becomes disordered with increasing temperature (above 120 Kelvin), indicating the onset of the premelting process. The surface premelting occurs from the defective boundaries between the Ih and Ic domains and can be promoted by the formation of a planar local structure. These results put an end to the longstanding debate on ice surface structures and shed light on the molecular origin of ice premelting, which may lead to a paradigm shift in the understanding of ice physics and chemistry.

Collective tourist destination recommendation refers to recommending tourist attractions to groups, which not only satisfies the diverse demands of consumers but also generates lucrative profits for tourism companies and further promotes macroeconomic development. However, collective recommendations are influenced by inconsistent evaluation criteria of individuals, the complexity of group decision making, and dynamically changed social relations. Hence, a dynamic trust network-based fuzzy group recommendation (DTN-FGR) model is proposed in this research. In this framework, the user-generated ratings are transformed into fuzzy preference relations (FPR) to tackle the problem of inconsistent individual evaluation criteria. Then a PageRank-based method is proposed to calculate the trust scores of each user in the trust network. Further, a mechanism for dynamic adjustment of trust networks is proposed based on dynamic decision making. Finally, a case study is carried out to verify the reliability and stability of the proposed DTN-FGR model. The results indicate that parameter variations have no effect on collective recommendations. In addition, the consensus degree of the proposed DTN-FGR model is the highest when compared with other collective recommendation models.

To elucidate the formation mechanisms of burn-on sand and metal penetration during sand casting, some laboratory experiments were carried out at different temperatures (1813, 1833, 1853, and 1873 K) and holding time (20, 40, 60, and 90 min) to simulate the interaction between ZG13Cr9Mo1VNbN stainless steel and chromite sand. The results demonstrate that the defects primarily consist of a mixture of the liquid phase, chromite, and metal. The main components of the liquid phase are SiO2, MnO, MgO, Cr2O3, FeO, and Al2O3, and the formation of Cr2O3through interfacial redox reactions has been discovered. The presence of a liquid phase plays a pivotal role in influencing burn-on sand and metal penetration. Interface reactions are prioritized, with burn-on sand maintaining a predominant influence. As the liquid phase quantity within the sand escalates, there is a corresponding incremental rise in the incidence of metal penetration. Even a minimal presence of the silicon element in steel can impact the liquid phase’s formation. Moreover, the decomposition or dissolution of chromite sand is a significant factor in the development of burn-on sand and metal penetration. Thus, a thorough investigation into the conditions and contributing factors of this phenomenon is essential for its effective management and mitigation.

Compelling evidence has shown that wetland methane emissions are more temperature dependent than carbon dioxide emissions across diverse hydrologic conditions. However, the availability of carbon substrates, which ultimately determines microbial carbon metabolism, has not been adequately accounted for. By combining a global database and a continental-scale experimental study, we showed that differences in the temperature dependence of global wetland methane and carbon dioxide emissions (EM/C) were dependent on soil carbon-to-nitrogen stoichiometry. This can be explained mainly by the positive relationship between soil organic matter decomposability and EM/C. Our study indicates that only 23% of global wetlands will decrease methane relative to carbon dioxide emissions under future warming scenarios when soil organic matter decomposability is considered. Our findings highlight the importance of incorporating soil organic matter biodegradability into model predictions of wetland carbon–climate feedback.

Excitotoxicity due to excessive activation of NMDARs is one of the main mechanisms of neuronal death during ischemic stroke. Previous studies have suggested that activation of either synaptic or extrasynaptic GluN2B-containing NMDARs results in neuronal damage, whereas activation of GluN2A-containing NMDARs promotes neuronal survival against ischemic insults. This study applied a systematic in silico, in vitro, and in vivoapproach to the discovery of novel and potential GluN1/2A NMDAR positive allosteric modulators (PAMs). Ten compounds were obtained and identified as potential GluN1/2A PAMs by structure-based virtual screening and calcium imaging. The neuroprotective activity of the candidate compounds was demonstrated in vitro. Subsequently, compound 15(aegeline) was tested further in the model of transient middle cerebral artery occlusion (tMCAO) in vivo, which significantly decreased cerebral infarction. The mechanism by which aegelineexerts its effect on allosteric modulation was revealed using molecular dynamics simulations. Finally, we found that the neuroprotective effect of aegelinewas significantly correlated with the enhanced phosphorylation of cAMP response element-binding protein (CREB). Our study discovered the neuroprotective effect of aegelineas a novel PAM targeting GluN1/2A NMDAR, which provides a potential opportunity for the development of therapeutic agents for ischemic stroke.

For atmospheric melting cast Cu–15Ni–8Sn alloy, hot extrusion tests were conducted on ingots of Cu–15Ni–8Sn alloy with varying extrusion ratios (5, 12 and 16) following homogenization and annealing. The investigation employed mechanical property tests, scanning electron microscopy and transmission electron microscopy to analyze the mechanical characteristics, dynamic recrystallization and twinning behaviors of the alloys subjected to different extrusion ratios. The findings revealed a reduction in the average grain size of the alloy as the extrusion ratio increased. The alloy undergoes dynamic recrystallization during hot extrusion, and the degree of recrystallization of the alloy escalated with higher extrusion ratios. The alloy underwent completely recrystallized at an extrusion ratio of 16, primarily driven by discontinuous dynamic recrystallization (DDRX). In addition, the alloy generated twins during the DRX process, and the twin boundaries provided favorable sites for the nucleation of DRX grains, which promoted the DRX of the alloy. Notably, at an extrusion ratio of 16, the alloy demonstrated impressive mechanical properties, with an ultimate tensile strength of 836 MPa and an elongation of 13.5 %. These results presented a substantial enhancement, showcasing a 54 % increase in the extruded ultimate tensile strength and a 350 % increase in the elongation compared to that of the alloy in the homogenized annealed state.

Abstract: This review summarizes the preparation methods of support ionic liquids (SILs) and their applications in rare metals separation. The rare metals separation includes the recovery of high value metal ions and the removal of heavy metal ions from wastewater. SILs can be used as a kind of highly efficient multifunctional separation materials. The preparation methods of SILs include chemical immobilization technique in which ILs moieties are supported on solid supports via covalent bonds and physical immobilization techniques in which ILs are immobilized on solid supports via physical method such as simple impregnation, sol-gel method. According to the difference of solid supports, this review summarizes the application of polymer supported ionic liquids (P-SILs), silica based material supported ionic liquids (SM-SILs) and membrane supported ionic liquids (M-SILs) in rare metals separation. P-SILs and SM-SILs prepared by chemical method with N-methylimidazolium group can be used as highly efficient anion exchangers with high thermal stability and good chemical stability for adsorption of Cr(VI), Re(VII), Ce(IV). P-SILs prepared via simple impregnation afforded IL functionalized solvent impregnated resins (SIRs) which showed high separation efficiency and selectivity in the separation of rare earths(III) (REs(III)). SM-SILs prepared via sol-gel method with IL doped in the support as porogens or extractant show high removal efficiencies and excellent stability for the separation of RE(III), Cr(III) and Cr(VI). M-SILs with IL as plasticizer or carrier show improved stability, high permeability coefficient and good selectivity for Cr(VI) transport. Different supports and different supporting methods were sufficiently compared. Based on the different practical application, different forms of SILs can be prepared for separation of rare metals with high separation efficiency and selectivity.

In this communication, a mode-modulated leaky wave antenna (LWA) composed of alternating arrangement of substrate-integrated coaxial lines (SICLs) elements and microstrip lines (MSLs) elements is proposed. This LWA can not only achieve continuous backward-to-forward scanning without open-stopband (OSB) effect but also has the characteristics of both wide bandwidth (BW) and high polarization purity. The radiation of the LWA is excited by mode discontinuities introduced between the transverse electromagnetic (TEM) waves supported by SICLs and quasi-TEM waves supported by MSLs, and continuous backward-to-forward beam scanning can be achieved by optimizing the spacing between the two discontinuities formed by the two modes in each period to suppress the in-phase superposition effect of reflected waves. Meanwhile, in this design, SICLs and MSLs have the same characteristic impedance and surface impedance, as well as the low dispersion, so that a wide operating BW can be achieved due to wideband impedance matching. In addition, due to the fully symmetric electric-field distributions of TEM and quasi-TEM modes, a high level of cross-polarization suppression can be achieved. Experimental results show that the proposed LWA can achieve continuous backward-to-forward scanning with 66% large relative impedance BW (6.4–12.7 GHz) and 65% large pattern BW (6.5–12.7 GHz), as well as a high cross-polarization ratio (XPR), which is measured to be about 27 dB.

Al–Li alloy has a wide range of application prospects in aerospace and rail transportation fields. Friction stir welding (FSW) is suitable for joining of Al–Li alloy. The microstructure evolution in FSW of Al–Li alloy determines the final joint properties. However, it is difficult to directly observe the microstructure evolution in FSW of Al–Li alloy only by experimental methods. Therefore, a Monte Carlo model in cooperation with a thermomechanical finite element model was proposed to study the microstructure evolution in FSW of 2195 Al–Li alloy. The validated thermomechanical finite element model was first used to calculate the temperature field, strain rate and strain evolution during the FSW process. Then, the achieved thermomechanical history was used in the Monte Carlo model to predict the transient microstructure evolution and the final morphology of the grain structure. It is found that the plastic materials on the advancing side experience a higher strain compared with that on the retreating side with the same distance from the joint line. The plastic material in the middle of the weld nugget zone (WNZ) experiences a relatively high temperature with more severe plastic deformation. Therefore, fully dynamic recrystallization takes place for the material at this region as it flows across the tool during FSW, which results in a fine recrystallization grain in the middle of WNZ. However, the material on the advancing side at 2 mm away from the joint line experiences a lower strain rate, which results in partial recrystallization with some relatively large grains of the base materials. The simulated average grain size and grain morphology were in good agreement with the measured results by EBSD method.

The master transcription factor receptor retinoic acid receptor-related orphan receptor γt (RORγt) regulates the differentiation of T-helper 17 (Th17) cells and the production of interleukin-17 (IL-17). Activation of RORγt+T cells in the tumor microenvironment promotes immune infiltration to more effectively inhibit tumor growth. Therefore, RORγt agonists provide a reachable approach to cancer immunotherapy. Herein, a series of biaryl amide derivatives as novel RORγt agonists were designed, synthesized, and evaluated. Starting from the reported RORγt inverse agonist GSK805 (1), “functionality switching” and structure-based drug optimization led to the discovery of a promising RORγt agonist lead compound 14, which displayed potent and selective RORγt agonist activity and significantly improved metabolic stability. With excellent in vivopharmacokinetic profiles, compound 14demonstrated robust efficacy in preclinical tumor models of mouse B16F10 melanoma and LLC lung adenocarcinoma. Taken together, current studies indicate that 14deserves further investigation as a potential lead RORγt agonist for cancer immunotherapy.

Deep subwavelength periodic structures support the efficient propagation of highly bounded surface electromagnetic (EM) waves, whereas leaky wave radiation requires secondary periodic modulation to enable wireless communication. However, the commonly used surface impedance modulation (SIM) method usually has the disadvantage of low leaky wave efficiency. In this communication, we apply the field-distribution modulation (FDM) method to help improve the radiation efficiency of the leaky wave antennas (LWAs) by periodically designing the discontinuity of electric-field distributions between two deep subwavelength periodic transmission lines (TLs). Specifically, we guide a pair of surface EM waves with electric fields concentrated on each side of the midline using two segments of single-conductor comb lines (SCCLs) with opposite grooving directions and achieve the effective leaky wave radiations by their interleaved arrangements to form a periodic field-distribution mismatch. Simulation and measurement results show that the FDM-assisted SIM SCCL LWAs can break through the modulated limitation of pure SIM and have a better performance in terms of radiation efficiency. Finally, we solve the low-efficiency problem that usually occurs in amplitude-weighted low sidelobe LWAs using the FDM method, and achieve the SCCL LWA with high efficiency and low sidelobe characteristics. These results indicate that the FDM method is expected to achieve more efficient leaky wave radiations of highly bounded surface EM waves.

This article presents a wideband irregular subarrayed design strategy with minimum module quantity, which decomposes the practical application problem into two subproblems according to the application scenarios and requirements. For the arrays tiled with irregular subarrays, we propose a wideband array partition method based on the principle that pattern matching is equivalent to excitation matching. The optimal module partition scheme is obtained by the K-means clustering method. Then, we propose a minimum module quantity estimation method to explore the relationship between the bandwidth and the number of modules. For modular array cases, we propose a wideband array hierarchical design strategy with minimum module quantity. The module partition model of the array with tiled module structure is solved by the weighted ${l_{1}}$-norm convex relaxation iterative optimization method. Both the design methods are able to obtain the optimal module partition scheme with the minimum quantity of modules and maintain good radiation performance. The effectiveness and potential of the proposed methods are verified by various numerical examples.

In this letter, we propose an optimal subarray design method for wideband irregular subarrayed array with sidelobe cancellation (SLC). First, we present the space–time adaptive SLC structure for wideband irregular subarrayed array. The main channel adopts the wideband beamforming method with module-level time delay and subarray-level phase-shifting, and the auxiliary channels are connected with multitap transverse filter banks to provide temporal degree of freedom. Considering the quasi-exact partition of the main array and the position constraints of the auxiliary elements, then we establish the optimal subarray design method to achieve the best interference cancellation performance, and use a two-step optimization method to get the results. The obtained subarray structure has better interference cancellation performance than the traditional method. The effectiveness and potential of the proposed method are verified by different numerical experiments.