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Lake sediments record the environment during the lake sedimentation whose characteristics can infer environmental changes and human activities. In this study, the 210Pb chronologies and sedimentation rate of the sediment core in Honghu Lake were calculated by the Constant Rate of Supply model. The characteristics of the sedimentary environment were analysed by using physical and chemical indicators. Four stages were divided as follows: Stage A (before 1900): The relatively low sedimentation rate and nutrient content indicated an extremely stable sedimentary environment. Stage B (1900–1949): With the growth of population, the intensity of land use began to increase, with an averaged sedimentation rate of 0.252 g·cm−2·a−1. Stage C (1949–1980): The sedimentation rate and nutrient content increased markedly. The intense human activity has damaged the surrounding vegetation leading to soil erosion and accelerated sedimentation rate. With the deterioration of the lake water environment, the organic matter source was mainly the internal source represented by algae and bacteria. Stage D (1980–2011): Influenced by the difference in land use types along the coast, the sedimentation rate of HH-A (0.570 g·cm−2·a−1) is higher than that of HH-B (0.445 g·cm−2·a−1). The results are of significance to the management of rural lakes and reservoirs.

The metallurgical changes and micro defects after welding can influence the mechanical property, corrosion resistance and dimensional stability of the stainless steel wielding joints. It is necessary to explore an effective post-welded method to improve the service performance for stainless steel welding joints. Furthermore, the essential mechanism between microstructure changes and macro-property variation during this process needs deep reveal. Therefore, this paper aims at investigating the effects of different post-weld treatments including naturally aging, artificial aging and cryogenic treatment on the residual stress and mechanical properties of 304 stainless steel weldments. The microstructure evolution was also studied to reveal and establish the microstructure-performance relationship. The results showed that the distribution of residual stress was most uniform with lowest magnitude (decreased by up to 49%) after cryogenic treatment. At room temperature, weldments subjected to the three post treatments showed similar mechanical properties. At cryogenic temperature, cryogenic treatment exhibited an outstanding role on maintaining the mechanical properties of weldments. By contrast, the mechanical properties were obviously reduced by artificial aging. The transformation of δ-ferrite and the carbide precipitation in grain boundaries are the main reasons for the decrease of mechanical properties after artificially aging. Welding process was able to cause the transfer of the alloying elements and decrease the stability of austenite. Consequently, martensitic transformation can be induced during cryogenic treatment. The new formed martensite resulted in the refined microstructure and high mechanical properties of weldments, and also the release of residual stress after welding.

In order to accurately assess the risk of the hybrid AC/DC network under fault, a risk assessment method for the hybrid AC/DC system based on the transient energy function is proposed. First, based on the energy transfer relationship of the hybrid AC/DC power system, the transient energy function model of the hybrid AC/DC system is established. Based on the operating data of the power grid, the energy function is used as an efficiency variable, and the efficiency variable is integrated into the prior risk probability calculation of nodes in the network, and a Bayesian network-based risk assessment model of hybrid AC/DC system is established. Considering the dynamic update model of network cascading failures, the clique tree propagation algorithm is used to dynamically calculate the posterior risk probability of the node to realize the dynamic assessment of the network risk. Finally, the improved IEEE-39 node hybrid AC/DC system is used as an example for analysis. The results show that the proposed model can not only effectively evaluate the overall safety of the network, but also has feasibility in predicting faults, which can provide a theoretical basis for the stability control of the hybrid AC/DC system.

Electrochemical biosensors have emerged as powerful tools for the ultrasensitive detection of lung cancer biomarkers like carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and alpha fetoprotein (AFP). This review comprehensively discusses the progress and potential of nanocomposite-based electrochemical biosensors for early lung cancer diagnosis and prognosis. By integrating nanomaterials like graphene, metal nanoparticles, and conducting polymers, these sensors have achieved clinically relevant detection limits in the fg/mL to pg/mL range. We highlight the key role of nanomaterial functionalization in enhancing sensitivity, specificity, and antifouling properties. This review also examines challenges related to reproducibility and clinical translation, emphasizing the need for standardization of fabrication protocols and robust validation studies. With the rapid growth in understanding lung cancer biomarkers and innovations in sensor design, nanocomposite electrochemical biosensors hold immense potential for point-of-care lung cancer screening and personalized therapy guidance. Realizing this goal will require strategic collaboration among material scientists, engineers, and clinicians to address technical and practical hurdles. Overall, this work provides valuable insight for developing next-generation smart diagnostic devices to combat the high mortality of lung cancer.

MXene (Ti3C2Tx) is a promising electrode material for supercapacitors. However, the current MXene material preparation process often requires hydrofluoric acid, and the etched MXene is easily oxidized and stacked, which is not conducive to the transfer of electrons and ions. In this study, we proposed a high concentration of sodium hydroxide solution mixed with sodium hypochlorite solution as an etchant for the preparation of fluorine-free MXene (Ti3C2Tx). Based on the alkali-assisted hydrothermal method, Ti3AlC2 was used as the raw material, and 10 % NaClO aqueous solution was added as the oxidant during the etching process to accelerate the etching and in-situ generate TiO2 with excellent conductivity. When the oxidation time is 12 h and the amount of NaClO is 0.2 mL, the TiO2 particles in-situ generated by the oxidation of Ti element in MXene are evenly distributed on the surface and interlayer of the material, which effectively curbs the stacking problem between the Ti3C2Tx layers and improves the specific surface area of the material. The prepared MXene/TiO2 electrode in 1 M H2SO4 electrolyte, − 0.5–0.2 V voltage window, the highest mass specific capacity can reach 321F/g, and after 10,000 charge–discharge cycles, the capacitance retention rate can still reach 86.4 %, which is higher than the capacitance retention rate of Ti3C2Tx material (81.7 %).

The Augmented Transformer U-Net (AugTransU-Net) is proposed to address limitations in existing transformer-related U-Net models for brain tumor segmentation. While previous models effectively capture long-range dependencies and global context, these works ignore the hierarchy to a certain degree and need more feature diversity as depth increases. The proposed AugTransU-Net integrates two advanced transformer modules into different positions within a U-shaped architecture to overcome these issues. The fundamental innovation lies in constructing improved augmentation transformer modules that incorporate Augmented Shortcuts into standard transformer blocks. These augmented modules are strategically placed at the bottleneck of the segmentation network, forming multi-head self-attention blocks and circulant projections, aiming to maintain feature diversity and enhance feature interaction and diversity. Furthermore, paired attention modules operate from low to high layers throughout the network, establishing long-range relationships in both spatial and channel dimensions. This allows each layer to comprehend the overall brain tumor structure and capture semantic information at critical locations. Experimental results demonstrate the effectiveness and competitiveness of AugTransU-Net in comparison to representative works. The model achieves Dice values of 89.7%/89.8%, 78.2%/78.6%, and 80.4%/81.9% for whole tumor (WT), enhancing tumor (ET) and tumor core (TC) segmentation on the BraTS2019-2020 validation datasets, respectively. The code for AugTransU-Net will be made publicly available at https://github.com/MuqinZ/AugTransUnet.

The two-dimensional thermodynamically consistent phase field model, which consists of the anisotropic Allen-Cahn type equation and the heat equation, is used to study the morphological pattern of the particle in the initial stage of crystal growth. The results reveal the locally reversible growth of the particle in the initial stage of crystal growth. Specifically, some parts of the particle interface first grow inward, while others grow outward from the interface of critical nucleation, until the growth speed of the interface becomes zero. After this, the inward growth parts start to grow outward with other parts. The locally reversible growth of the particle leads to the development of a petal-like shape. The particle radius size dependence of the temperatures along the parts of the particle interface in different crystallographic directions at different time points is studied. By a series of results, the correlations between the morphological pattern selection of the particle and the model parameters, including undercooling and anisotropic strength, are analyzed. These results contribute to understanding the fundamental mechanism of the particle evolution during crystal growth.

IntroductionAutism Spectrum Disorder (ASD) has a significant impact on the health of patients, and early diagnosis and treatment are essential to improve their quality of life. Machine learning methods, including multi-classifier fusion, have been widely used for disease diagnosis and prediction with remarkable results. However, current multi-classifier fusion methods lack the ability to measure the belief level of different samples and effectively fuse them jointly.MethodsTo address these issues, a multi-classifier fusion classification framework based on belief-value for ASD diagnosis is proposed in this paper. The belief-value measures the belief level of different samples based on distance information (the output distance of the classifier) and local density information (the weight of the nearest neighbor samples on the test samples), which is more representative than using a single type of information. Then, the complementary relationships between belief-values are captured via a multilayer perceptron (MLP) network for effective fusion of belief-values.ResultsThe experimental results demonstrate that the proposed classification framework achieves better performance than a single classifier and confirm that the fusion method used can effectively fuse complementary relationships to achieve accurate diagnosis.DiscussionFurthermore, the effectiveness of our method has only been validated in the diagnosis of ASD. For future work, we plan to extend this method to the diagnosis of other neuropsychiatric disorders.

Currently, impacts of rapid cropland reclamation and its intense structural changes in internal paddy-upland on ecosystem service are insufficient in Sanjiang Plain, China. Further, land management systems of Sanjiang Plain consist of state-owned and private farms; however, exploring the impact of different land management systems on “land use–landscape–ecosystem service” is still lacking. To reveal this issue, the integrated methodology of “land dynamic tracking–landscape index–improved ecosystem service assessment” was established. Results are displayed below: From 1990 to 2020, land use was featured by decreases in forest (−3308.62 km2), grassland (−6030.86 km2), waters (−475.81 km2), and unused land (−3037.27 km2), with a slight increase in constructed land (+403.25 km2) and a rapid increase in cropland (+12,447.56 km2). Although nearly equal increments of cropland on state-owned and private farms (i.e., 6156.70 km2 vs. 6290.86 km2) were monitored, different cropland structure changes were still revealed, namely a drastic expansion of paddy fields (13,788.32 km2) and an acute decrease in upland crops (−7631.62 km2) on state-owned farms, but both a slight increments in paddy fields (5920.08 km2) and upland crops (370.78 km2) on private farms. For landscape, private farms were more fragmented (SHDI = +0.63%), causing a decrease in aggregation (AI = −0.56%) and a more complex shape (LSI = +23.3%), by contrast, state-owned farms displayed an increased integrity (SHDI = −9.88%), along with an increase in aggregation (AI = +0.43%) and simplified shape (LSI = −13.30%). Evaluated ecosystem service value changed from 338.62 to 296.25 billion yuan from 1990 to 2020, a loss rate of 12.58% in Sanjiang Plain. Then, a new finding showed a higher loss rate on state-owned than private farms (i.e., 30.15% vs. only 6.18%). This study revealed differentiated processes of “land use–landscape–ecosystem service” in different land management system regions in China, providing new findings in the fields of land management system, ecological landscape, and environment.

The effects of post-weld aging and cryogenic treatment on self-fusion welded austenitic stainless steel thick plates were investigated in the present work. The results showed that fusion zone microstructure consisted of austenite matrix and vermicular ferrite. Aging treatment promoted the decomposition of δ-ferrite into σ-ferrites as well as the precipitation of carbides. Isothermal martensitic transformation in the Tungsten Inert Gas Welding (TIG) specimen was induced by cryogenic treatment, and stacking faults were increased. The fusion zone microstructure of Electron Beam Welding (EBW) and Laser Welding (LW) was finer than that of TIG, with acicular ferrite distributed in the austenite matrix. A large number of twins were generated in the austenite matrix after LW. Cryogenic treatment produced a large number of sub-grains in LW specimens, which was due to the entanglement and accumulation of dislocations in the vicinity of ferrite. Post-weld aging and cryogenic treatment have no influence on the strength of weldments with different welding methods while cryogenic treatment could improve the impact toughness of EBW and LW weldments by the extent of 7.4% and 8.8%, respectively. The aging treatment reduced the impact toughness by 49%, 33% and 15.5%, as well as the uniform elongation by 44%, 39% and 17% for TIG, EBW and LW, respectively. Aging treatment reduced the surface residual stress of TIG weldment by 58.8% in Y direction and 61.2% in X direction. Cryogenic treatment at could also release the surface residual stress of TIG weldment by 36.8% in X direction and 16.3% in Y direction.

In recent years, significant oil and gas discoveries have been achieved in the Permian Upper Wuerhe Formation and the Triassic Baikouquan Formation on the marginal slope of oil generation sag, Junggar Basin. However, in the central sag of the basin, no oil or gas show has been discovered in target formations, and low production has been made only by two wells. As a result, it is necessary to deepen the understanding of the mechanisms of oil and gas accumulation and clarify the main controlling factors. The analyses of the accumulation conditions in the central sag and some wells show that the direct reason for the failure to find oil and gas in the sag is the lack of local source-connecting faults and poor reservoir properties. An accumulation model with source in the lower section and reservoir in the upper section controlled by both source-connecting faults and favorable sand bodies was established for the Permian and Triassic strata in the sag. The sandbody lithologic reservoirs of fan-delta front subfacies in the Upper Wuerhe and Baikouquan formations under the background of stratigraphic overlap are the primary direction of exploration, covering an area about 3 600 km2. The comprehensive exploration of unconventional oil and gas in the Middle-Lower Permian source rocks and conventional oil and gas in multiple layers outside the source area should be targeted.

Study region: This study interrogates a landslide in ice-rich permafrost region in the Eastern Qinghai–Tibet Plateau, China. Study focus: Climate warming has increased the frequency and intensity of rainfall events, changing hydrothermal processes and the soil mechanical properties, thus affecting slope stability in permafrost region. The purpose of this paper is to elucidate the variations in soil volumetric water content (VWC) which may influence the mechanical properties of unstable slopes in ice-rich permafrost region under different rainfall conditions. New hydrological insights for the region: This paper integrates the rainfall infiltration boundary conditions and Mohr–Coulomb criterion into a thermo–hydro–mechanical (THM) model and analyzes a landslide case in the permafrost regions. The results show that the THM model can effectively account for the impacts of VWC variation under different rainfall conditions. The influence of rainfall on the VWC diminishes as depth increases, with a more pronounced effect observed at depths less than 1 m. At depths exceeding 1 m, the impact is relatively minor. Under the condition of low-intensity, long-duration rainfall, with accumulated precipitation exceeding 60 mm, the cohesion and internal friction angle decrease to 4.2kPa and 8.1°, respectively, with a deep-layer integral slippage. In contrast, under the condition of high-intensity, short-term rainfall, the accumulated rainfall exceeds 75 mm and the internal friction angle decreases from 39° to 26°, with shallow-layer slippage. The results add on to our understanding engineering problems and periglacial geomorphic processes under the influence of climate warming.

Rapid advancements in construction technologies have accelerated the development of complex and deep underground structures, raising concerns about the impact of groundwater on structures, particularly anti-floating measures. Traditional tensioned anchors, commonly used for preventing flotation, suffer from limitations like low pull-out bearing capacity, shallow critical anchoring depth, and localized stress concentration. To overcome these limitations, this paper introduces a tension–compression dispersed composite anchor, which combines casing, load-bearing plates, and tensioned anchors. Comparative tests were conducted between these composite anchors and traditional tensioned anchors to analyze their anchoring behavior. Our results show that tensioned anchors exhibit a stable axial force distribution as anchoring length increases. By identifying abrupt changes in the axial force curve, optimal anchoring lengths for load-dispersed anchors can be determined, thereby enhancing rock and soil strength utilization. The tension–compression-dispersed composite anchor outperforms tensioned anchors, with 1.44 times the ultimate bearing capacity for equivalent anchoring lengths and 1.1 times the capacity for an additional 1 m length. It also displays superior deformation adaptability and structural ductility under high-bearing loads compared to tensioned anchors with extended anchoring lengths. Effectively mobilizing the strength of the lower anchoring segment within the rock and soil results in a lower critical anchoring depth and a more uniform distribution of lateral friction resistance. In conclusion, the tension–compression-dispersed composite anchor offers significant advantages, making it a promising engineering solution for anti-floating anchor systems in complex underground environments.

We consider the Cox–Ingersoll–Ross (CIR) model in time-dependent domains, that is, the CIR process in time-dependent domains reflected at the time-dependent boundary. This is a very meaningful question, as the CIR model is commonly used to describe interest rate models, and interest rates are often artificially set within a time-dependent domain by policy makers. We consider the most fundamental question of recurrence versus transience for normally reflected CIR process with time-dependent domains, and we examine some precise conditions for recurrence versus transience in terms of the growth rates of the boundary. The drift terms and the diffusion terms of the CIR processes in time-dependent domains are carefully provided. In the transience case, we also investigate the last passage time, while in the case of recurrence, we also consider the positive recurrence of the CIR processes in time-dependent domains.

Carbon molecular deposition in sediments removes organic carbon (OC) from the biosphere-atmosphere carbon cycle and therefore limits the emission of greenhouse gases (i.e. CH4 and CO2) from natural water systems. At present, the occurrence characteristics, deposition fluxes, and driving force of OC components in the river-lake ecotone are unclear. Here, the tempo-spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and Σn-alkanes (nC13–nC32) related to organic nitrogen (ON) and OC in the estuarine sediments from Poyang Lake and their sources and effects were investigated. The ON and OC contents in the sediment cores ranged from 0.35−0.64 % and 1.9–4.24 %, respectively, and the PAH fluxes varied between 672.19 and 24703.97 ng cm−2 a-1, showing an upward risk to the water bodies and human health. In particular, it is worth noting that the 5–6 ring monomers were dominant, accounting for 66.48 % of the ΣPAHs in the sediment profile. The sources were mainly derived from biomass combustion and automobile exhaust emissions, while the latter proportion has increased in recent decades. In the sediment profile, the n-alkane abundance peak was found at nC31 with a marked odd-even predominance. The deposition flux for Σn-alkanes ranged between 10.92 and 73.46 μg cm−2 a-1. In addition, long-chain monomers dominated the Σn-alkanes and were found to be herbaceous in origin. An analysis of the environmental indicators in the sediment layers showed that forest restoration and the eutrophication of water bodies caused by anthropogenic stress and climate change were mainly responsible for the relatively large contribution made by vascular plants and autochthonous organisms.

Abstract To study the spatial occurrence, sources, and ecological risks of 16 PAHs, surface sediments had been collected from seven major areas of Taihu Lake, China in April 2021. Results showed that the concentrations of ∑16PAHs varied between 1381.48 and 4682.16 ng g−1, and the contents of BghiP in each sample were the highest. The PAHs concentrations in the sediments near the lakeshore were much higher than those in the central area of the lake. The sedimentary ∑16PAHs were mainly composed of molecular-weight monomers and 4-ring PAHs showed superiority (35.69–45.02%). According to the ratio of PAH monomer, the sedimentary PAHs in Taihu Lake were dominantly derived from the combustion. Through the biological toxicity assessment and the BaP equivalent (BaPE), great biological risks of PAHs monomers i.e. DahA and IcdP were found. Both concentrations of ∑16PAHs and dominant 4–6-ring monomers accompanied by carcinogenic risks in many areas of Taihu Lake increased. It is necessary to strengthen monitoring and take measures to control the input of organic pollutants.

Carbon burial in lake sediments has a profound impact on the global carbon cycle. In this study, the burial characteristics of organic carbon (OC) in typical sediments from the Poyang basin over the past hundred years were investigated and the influencing factors and driving mechanism were determined. The results showed that carbon burial in the Poyang basin sediments was mainly driven by human activities, whereas the change in the OC accumulation rate was related to precipitation, forest land area, water area, construction land area, urbanization rate, application of agricultural fertilizers, per capita GDP and population.

(1) Objective: to accelerate the digitalization of the elderly care service industry and the construction of the smart elderly care industry, this paper designs an intelligent e-procurement system for elderly suppliers selecting from the perspective of smart elderly care, which can enhance the efficiency of elderly care supply chains and assist manufacturers of elderly products in choosing a reliable, high-quality supplier during trades. (2) Methods: the e-procurement system, including six modules, is built with an improved dynamic Markov Decision Process selection model combined with an Analytic Network Process, bringing dynamic evolution of both inventory cost and purchasing cost into long-term reward calculation, and taking into account 15 common indexes and 7 specific indexes when evaluating suppliers’ competitiveness. (3) Results: a real sample shows that when facing 50 suppliers with 50 different quotations, the e-procurement system selects a stable and reliable supplier that brings the best long-term profits for demand enterprises in ten purchase periods, and it makes the selecting process more efficient and more prompt. (4) Conclusions: the model can be used in the circumstance where an elderly product producer is forced to decide on a long-term strategy or reselect a new stable supplier since it is focused on choosing long-term and high-quality suppliers over numerous periods.

The rapid economic development in the Yangtze River Delta has affected the carbon (C) pool in lake sediments, which has become a serious environmental management issue. To explore the characteristics of composition, spatial distribution and burial of organic C (OC) in lacustrine sediments, a typical shallow lake was targeted to compare the heavy fraction OC (HFOC), light fraction OC (LFOC), and dissolved OC (DOC) in the surface sediments of different lake areas using the specific gravity separation approach. The effects of environmental factors on the form of OC present were identified by a redundancy analysis. The results showed a regional difference of DOC, LFOC, and HFOC concentrations in Taihu Lake, and HFOC was dominant in the OC buried in lake sediments. The deposition rate of OC in Taihu Lake sediments varied in a ranged of 31.91–114.47 g C m−2 a-1. The LFOC levels in the sediments were lower than those in other lakes. Both sedimentary LFOC and HFOC were significantly correlated with the nitrogen (N) content, indicating that the C sink was enhanced by an increase in N in the sediments. The grass-type lake zone stimulated C accumulation in Taihu Lake sediments.

Aluminum matrix composites have been widely used in aerospace and automotive fields due to their excellent physical properties. Cryogenic treatment was successfully adopted to improve the performance of aluminum alloy components, while its effect and mechanism on the aluminum matrix composite remained unclear. In this work, the effects of cryogenic treatment on the microstructure evolution and mechanical properties of 15%SiCp/2009 aluminum matrix composites were systematically investigated by means of Thermoelectric Power (TEP), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results showed that TEP measurement can be an effective method for evaluating the precipitation characteristics of 15%SiCp/2009 aluminum matrix composites during aging. The addition of cryogenic treatment after solution and before aging treatment promoted the precipitation from the beginning stage of aging. Furthermore, the aging time for the maximum precipitation of the θ″ phase was about 4 h advanced, as the conduction of cryogenic treatment accelerates the aging kinetics. This was attributed to the great difference in the linear expansion coefficient between the aluminum alloy matrix and SiC-reinforced particles, which could induce high internal stress in their boundaries for precipitation. Moreover, the lattice contraction of the aluminum alloy matrix during cryogenic treatment led to the increase in dislocation density and micro defects near the boundaries, thus providing more nucleation sites for precipitation during the aging treatment. After undergoing artificial aging treatment for 20 h, the increase in dispersive, distributed precipitates after cryogenic treatment improved the hardness and yield strength by 4% and 16 MPa, respectively.