作者机构：
[Luo, Qiao; Yu, Hongbing] Hunan City Univ, Coll Architecture & Urban Planning, Yiyang 413000, Peoples R China.;[Luo, Qiao; Yu, Hongbing] Hunan City Univ, Coll Architecture & Urban Planning, Lab Key Technol Digital Urban Rural Spatial Planni, Yiyang 413000, Peoples R China.;[Li, Yong] Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atmo, Beijing 100029, Peoples R China.;[Jiang, Shufang; Cao, Xueyou] Forestry Bur Yiyang City, Yiyang 410004, Peoples R China.
通讯机构：
[Li, Y ] C;Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atmo, Beijing 100029, Peoples R China.
关键词：
South Dongting Lake Nature Reserve;blue space;green space;precipitation;air temperature
摘要：
In recent years, the water level of the Dongting Lake (DTL) has been continuously low, and the wetland area and landscape pattern have changed significantly. Considering the obvious spatial heterogeneity of water regime changes in different waters of the DTL, this paper takes two core areas of the South Dongting Lake Nature Reserve (SDLNR) as study areas and analyzes the spatial distribution characteristics of the wetland blue–green landscape patterns by using remote sensing image data and hydrological and meteorological data. The multi-scale correlation between runoff, precipitation, temperature, and evapotranspiration in the SDLNR was studied via cross-wavelet transform analysis. The results show the following: (1) The change in the blue–green spatial patterns in different regions in different periods is inconsistent, and this inconsistency is related to the topography, climate, and human activities in each region; (2) there are seasonal fluctuations in precipitation, air temperature, and evapotranspiration in the SDLNR. Among them, the annual mean temperature shows a rising trend and passes the significance test with 95% confidence, while the annual mean precipitation and annual mean evapotranspiration show no significant change trend; and (3) our Pearson correlation analysis and cross-wavelet change results show that precipitation and temperature are strongly correlated with runoff, with a resonance period of 8–16 months, while the correlation between evapotranspiration and runoff is not significant. We recommend that policymakers establish an effective early warning system and make plans to store water through micro-terrain transformation in possible climate change treatments and strategies.
摘要：
Kaempferol (KA), which is a biologically active natural polyphenol compound with considerable medicinal value, can be used to fight various diseases. Herein, a beta-cyclodextrin/fullerene-graphene oxide/Nickel-metal-organic framework (beta-CD/C-60-GO/Ni-MOF) composite-based electrochemical sensor was developed to detect KA; the composite was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron (XPS) spectroscopy. The biocompatibility and host-guest recognition performance of beta-cyclodextrin (beta-CD); the porosity and the catalytic performance of the nickel-metal-organic framework (Ni-MOF); and the excellent electrical conductivity of fullerene-graphene oxide (C-60-GO) work together to considerably improve the detection performance of the sensor for KA. The sensor has an extensive linear range (0.5-50 mu M) and a low detection limit (58 nM) with an electrochemically active specific surface area of 0.0971 cm(2); furthermore, the redox mechanism of KA in the sensor is explained. For the detection of actual natural samples of broccoli containing KA, satisfactory recovery rates and accuracy were observed; the recovery rate was 96.4 %-101.1 %.
作者：
Wang, Xinzhong;Li, Linshu;Xiang, Yi;Wu, Yuexing;Wei, Mei
期刊：
Frontiers in Materials,2024年10 ISSN：2296-8016
通讯作者：
Wang, XZ
作者机构：
[Li, Linshu; Wang, XZ; Wang, Xinzhong; Wu, Yuexing; Xiang, Yi] Hunan City Univ, Sch Civil Engn, Yiyang, Peoples R China.;[Wei, Mei] Hunan Arts & Crafts Vocat Coll, Sch Digital Arts, Yiyang, Peoples R China.
通讯机构：
[Wang, XZ ] H;Hunan City Univ, Sch Civil Engn, Yiyang, Peoples R China.
关键词：
concrete-filled steel tube;basalt fiber;short columns;finite element analysis;bearing capacity;ductility coefficient
摘要：
With rapid economic and social development, both concrete-filled steel tube (CFST) composite structures and basalt fiber (BF) have been widely applied in the field of civil engineering. To investigate the laws and characteristics of the influence of chopped BF on the mechanical properties of CFST columns and further promote the application of BF in CFST structures, the axial compressive bearing capacity test of 18 CFST short columns was carried out, and the influence of BF of different lengths on their structural mechanical properties was analyzed. The test results were compared with the theoretical calculation results and the finite element analysis results to verify the reasonableness of the test results. The results reveal that the axial compressive bearing capacity of the CFST short column after adding BF is significantly improved compared to the ordinary CFST short column, in which the bearing capacity and the ductility coefficient are increased by approximately 8.1% and 31.6%, respectively, on average. In addition, changing the length of BF has less effect on the bearing capacity of CFST short columns, the rate of increase in bearing capacity decreases with an increase in the steel ratio of CFST, and the coefficient of ductility increases with the increase in the steel ratio.
关键词：
Asphalt mixture;Mesoscopic analysis;Skeleton evolution;Aggregate contact;Particle movement;Discrete element method
摘要：
The aggregate skeleton is the intrinsic core of asphalt mixtures for load transfer, which is quite different under various gradations. For evaluating the loading characteristics of the aggregate skeleton, this research combined the 3D blue -ray scanning technology and discrete element method (DEM) to establish the numerical models of different graded asphalt mixtures considering the real aggregate morphology. A linear parallel bond model was used to simulate the adhesion effect of asphalt, and the uniaxial compression numerical simulation was verified by indoor tests. In addition, the contact force, contact number, anisotropy, and rotation angle were used to evaluate the aggregate skeleton evolution under uniaxial compression loading. Furthermore, the contribution of each grade aggregate in the gradation to the skeleton structure was analyzed. Results show that the average contact force is higher in large -size aggregates above 9.5 mm, which exhibit greater load transfer efficiency. Moreover, 4.75-9.5 mm size aggregates combine the functions of bearing and filling, and its role is significantly affected by the gradation. It is also found that the internal skeleton structure can be optimized and adjusted under stress. The contact numbers of different graded mixtures follow a close decrease, and the strong contacts are mostly provided by coarse aggregates above 4.75 mm. The anisotropy development of aggregate skeleton contact force is induced by the stress, and the deviator fabric of asphalt mixtures show a good linear positive correlation with the uniaxial compressive strength (UCS). Besides, fine aggregates exhibit greater cumulative rotation angle and instability effect, it is feasible to detect asphalt mixture deformation by the rotation angle of particles.
期刊：
Journal of Affective Disorders,2024年347:645-655 ISSN：0165-0327
通讯作者：
Xiang, YH;Li, XJ
作者机构：
[Xiang, Yanhui] Hunan City Univ, Teacher Educ Coll, Yiyang, Peoples R China.;[Cao, Rong; Xiang, Yanhui] Hunan Normal Univ, Cognit & Human Behav Key Lab Hunan, Changsha, Peoples R China.;[Cao, Rong; Xiang, Yanhui] Hunan Normal Univ, Dept Psychol, Changsha, Peoples R China.;[Li, Xiaojun] Nanjing Xiaozhuang Univ, Tao Xingzhi Res Inst, Nanjing, Peoples R China.;[Xiang, Yanhui; Xiang, YH] Hunan Normal Univ, Dept Psychol, Changsha 410081, Peoples R China.
通讯机构：
[Xiang, YH ] H;[Li, XJ ] N;Hunan Normal Univ, Dept Psychol, Changsha 410081, Peoples R China.;Nanjing Xiaozhuang Univ, Tao Xingzhi Res Inst, Nanjing 210038, Peoples R China.
关键词：
Adolescent depression;Country income level;Cross-national;Geographical region;Meta-analysis;Parental education level;Socioeconomic status
摘要：
Adolescent depression, as a common problem, has always been the focus of attention and research. However, no consistent conclusion has been drawn on its relationship with parental education level. Therefore, this study used meta-analysis and dose-response analysis techniques to explore the overall relationship between the two, and further explore the moderating factors affecting the relationship between the two through subgroup analysis and meta-regression analysis. After a literature search and screening, a total of 22 literatures were included, including 634,821 adolescents aged 9-25, distributed in 10 countries. The results showed that: (1) Overall parental education level was negatively correlated with adolescent depressive symptoms (RR=0.88. p < 0.001), and there was a dose-response relationship between the two. (2) Geographical location (p=0.002<0.05) and national economic development (p=0.03<0.05) significantly moderated and affected the association between parental education level and adolescent depression, thus presenting a global inconsistency. The results of this study provide a more accurate conclusion on the relationship between parental education and adolescent depression to some extent, highlight the importance and necessity of considering family, economic and cultural factors when studying and solving adolescent depression problems, and guide us to pay more attention to the cross-regional and cross-cultural differences in adolescent depression problems.
通讯机构：
[Zhang, L ] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;Hunan Univ Technol, Hunan Engn Res Ctr Struct Safety & Disaster Preven, Yiyang 413000, Peoples R China.
关键词：
boulder and hard rock environment;GPR;wavelet scale energy spectrum;wavelet packet energy;time-frequency characteristics
摘要：
The hard rocks in the stratum can pose safety risks and hinder the progress of urban underground tunnel construction using shield and jacking methods, thereby reducing construction efficiency and increasing construction costs. This paper utilizes wavelet scale energy spectrum, wavelet packet theory and statistical methods to conduct research on the detection of special geological formations such as hard rocks and voids, as well as the analysis of their signal time-frequency characteristics based on the ground-penetrating radar (GPR) technique. On the basis of calibrating the permittivity of different types of rock blocks, we established a forward model for detecting hard rocks and voids, and the simulated signals were analyzed in the time and frequency domains. Subsequently, laboratory experiments were conducted to perform GPR tests on different types of hard rocks in natural and water-saturated states and voids, to explore the time-frequency characteristics, frequency band energy variations, and statistical patterns of typical single-trace signals. The results show that the granite detection signal contains more low-frequency components, the sandstone detection signal contains more medium-low frequency components, while the limestone detection signal contains more medium-high frequency components in their natural state; the signal from the karst cave has relatively more low-frequency components than the signal from the empty cavity. The geometric shape of the rock has no influence on the dominant frequency and time-frequency distribution of its reflection signal. Generally, rocks with higher rebound values (hardness) also exhibit larger variance and standard deviation in frequency band energy. The research has important theoretical significance and practical value for the measurement and assessment of special geological features such as hard rocks and voids in urban underground trenchless construction.
摘要：
The attainment of formability in ceramic welding presents an imposing quandary within the realm of the manufacturing industry. In this article, the laser welding of Al2O3 ceramics was carried out to compare and analyze the influence of laser power, welding speed, laser duty cycle, and other process parameters on the macroscopic morphology of the weld, weld cracking rate, and welded joint properties. The results show that Al2O3 ceramic welds have a greater tendency to cracking and that the laser power should be matched to the appropriate welding speed. When heat input increases, the weld cracking rate decreases and then increases. Ceramic welded joints with a weld cracking rate of less than 30 % and a bending strength of more than 4 MPa can be obtained when the heat input range is 17-20.5 J/mm for continuous laser welding or 20.5-24 J/mm for pulsed laser welding. In addition, under high heat input conditions, pulsed laser welding reduces the tendency for weld cracking compared to continuous laser.
摘要：
The role of a shock generator in the fuel distribution of a scramjet engine is highly significant. In this article, the usage of the erected 3-lobe nozzle in the existence of a shock generator for fuel injection inside a supersonic combustion chamber is fully studied. A three-dimensional model of the extruded 3-lobe nozzle with two altitudes of 4 mm and 2 mm is produced to disclose the importance of the produced vortex upstream/downstream by the usage of the extruded injector. Comprehensive computational analysis is done to investigate the mixing efficiency and fuel diffusion of the proposed jet configuration. Impacts of the coaxial inward air jet on the hydrogen dispersion of the annual extruded 3-lobe injector are also revealed in the present research. The results of the flow structure indicate that the produced vortex upstream of the erected nozzle improves the fuel dispersion behind the hydrogen jet. Our findings show that the effects of injector height are more considerable than the use of an inner air jet for advance of the fuel mixing within the combustor of a scramjet engine.
期刊：
Journal of Materials Engineering and Performance,2024年 ISSN：1059-9495
通讯作者：
Jiang, BC;Jiang, Bingchun;Zhao, J
作者机构：
[Jiang, Bingchun] Guangdong Univ Sci & Technol, Dongguan, Peoples R China.;[Jiang, Bingchun; Zhao, Jun; Lu, Liwei; Liu, Yang; Zhao, J] Hunan City Univ, Yiyang, Peoples R China.;[Chai, Yanfu] Shaoxing Univ, Shaoxing, Peoples R China.
通讯机构：
[Jiang, BC; Zhao, J ] H;[Jiang, BC ] G;Guangdong Univ Sci & Technol, Dongguan, Peoples R China.;Hunan City Univ, Yiyang, Peoples R China.
关键词：
Gd and Mn alloying;Mg-Bi alloy;texture;tensile properties
摘要：
This study investigated the effect of the synergistic addition of Gd and Mn on the microstructure and mechanical properties of extruded Mg-1Bi alloys. The grain size of an Mg-1Bi alloy decreased sharply when either only Gd or Mn was added to the alloy, whereas a strong grain refining effect was verified upon the co-addition of Gd and Mn. The Mg-1Bi and Mg-1Bi-0.4Mn alloys exhibited typical strong basal textures, whereas the Mg-1Bi-0.3Gd and Mg-1Bi-0.3Gd-0.6Mn alloys showed weakened extrusion direction (ED)-split textures. The weakened ED-split texture leads to a high average Schmid factor for basal slip (SFb). Higher SFb for the sheet exhibited the lower yield strength and higher ductility. Furthermore, the synergistic addition of Gd and Mn resulted in considerably higher strength and ductility than the addition of either Gd or Mn alone. The Mg-1Bi-0.3Gd-0.6Mn sheet shows the ultimate tensile and yield strengths of similar to 275.6 and similar to 180.2 MPa along the transverse direction (TD) and similar to 273.2 and similar to 155.4 MPa along the extrusion direction (ED), respectively. Moreover, the elongation of Mg-1Bi-0.3Gd-0.6Mn sheet along the TD and ED increased to similar to 7.3 and similar to 7.5%, respectively, more than two times compared with the corresponding values for the Mg-1Bi sheet. The increased yield strength of the Mg-1Bi-0.3Gd-0.6Mn sheet was mainly attributed to the effect of refined grain size, fine alpha-Mn and MgBiGd particles, and the Gd solute. In addition, the ductility of the Mg-1Bi-0.3Gd-0.6Mn sheet was substantially increased because of the fine grain size and weak texture having a high average SFb.
摘要：
Single-atom catalysts have wide application prospects in peroxydisulfate (PDS)-based advanced oxidation process to degrade organic pollutants, but its catalytic performance is limited due to its cost, Metal-N coordination number, and single-atom loading amount. Herein, a novel nitrogen doped algal-based carbon confined singleatom copper catalyst (Cu-N/C-SAC((S))) was synthesized using molten salt assisted pyrolysis and coupling with PDS to degrade tetracycline (TC). AC-HAADF-STEM and XAFS analysis proved that single atom Cu was loaded (Content 1.9 %) successfully and coordinated with two N and two C. XPS and XANES spectra analysis suggested that Cu atoms mainly existed in a positive divalent state in Cu-N/C-SAC(S). When the catalyst dosage of Cu-N/CSAC((S)) was 0.1 g/L, TC was almost completely removed. Moreover, Cu-N/C-SAC(S) had a broad pH adaptation range and strong ability against interference. Singlet oxygen (O-1(2)), superoxide radicals (center dot O-2(-)), and electron transfer had an important contribution for TC removal. DFT calculations confirmed that the activation process of Cu-N/C-SAC((S)) producing SO4 center dot- was easier than the nitrogen doped blue-green algal-based carbon (N-BGAC). In addition, Cu-N/C-SAC((S)) possessed good recyclability and stability. The main degradation pathways of TC were analyzed, and the toxicity of the intermediates was calculated. This study provides a new solution strategy for the resource utilization of waste biomass, and provides technical support and theoretical guidance for the efficient application of single-atom catalysts in organic wastewater.
摘要：
With the advancements in low-power and miniature electronics, various smart devices are deployed and interconnected as the Internet of Things (IoT), collecting a massive amount of data from surrounding environments. Despite the popularity of ZigBee for low-power communications in IoT, WiFi has recently been recommended for data collection in IoT for its high data rate, high reliability, native IP compatibility, and vastly-deployed infrastructures. However, it is well known that WiFi is energy-consuming. Although many schemes have been designed to reduce WiFi energy consumption, they usually suffer from the dilemma that a longer (shorter) sleep of WiFi gives a lower (higher) energy consumption but a larger (smaller) latency, hindering the use of WiFi in a wide range of IoT applications that require a certain level of quality of service (QoS). To this end, we propose a Heterogeneity-aware Dual-interface Scheduling (HDS) scheme to fully exploit the heterogeneity between ZigBee and WiFi to realize energy-efficient and delay-constrained data collection in a tree-based IoT network, where each device is equipped with a ZigBee and a WiFi interface. The low-power feature of ZigBee is utilized as much as possible for high energy efficiency, while the high-reliability advantage of WiFi is leveraged when the ZigBee link quality is low for delay guarantee. Under network dynamics, HDS jointly allocates ZigBee and WiFi schedules to strike a balance between energy and delay for optimized performance. A prototype system is built atop an IoT platform integrated with commercial off-the-shelf ZigBee and WiFi modules. Experiment results show that the energy consumption of HDS is 80.3% and 43.6% lower than the standard power saving protocol and a state-of-the-art dual-interface scheme, respectively, under a moderate delay constraint. Additionally, the percentage of data packets that satisfy the delay constraint is above 98.6%.
作者机构：
[Chen, Cong; Zhang, Yi; Chen, C; Yin, Xuni] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle, Changsha 410082, Peoples R China.;[Yin, Xuni] Hunan City Univ, Sch Mech & Elect Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Chen, C ] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle, Changsha 410082, Peoples R China.
关键词：
Al 2 O 3 ceramic;Laser welding;Cracking rate;Heat input;Preheating
摘要：
Crack defects in ceramic welding are a significant challenge in electronic packaging that requires urgent resolution. In this study, fiber laser-based welding was employed to join 1 mm thick Al2O3 ceramic plates. The investigation focused on weld surface formation, crack defects, and performance attributes across varying heat input and preheating temperatures. The findings indicate a propensity for crack initiation at the weld center or within the base material during Al2O3 ceramic laser welding. Nonetheless, the susceptibility to cracking in Al2O3 welded joints can be mitigated, and joint flexural strength enhanced by adjusting heat input or by introducing a preheating treatment. The flexural strength peaked at a preheating temperature of 100 degrees C, exhibiting a 112 % increase compared to non-preheated welded joints. In addition, the best matching relationship between heat input and the preheating temperature was obtained through numerical calculations. The relationship between heat input and preheating temperature determines the cracking tendency region, and based on their interrelation, the cracking tendency region is partitioned into three distinctive regions. Subsequently, the three regions were experimentally validated, with results exhibiting a high degree of congruence, thereby offering significant guidance in the selection of laser welding parameters for Al2O3 ceramics.
摘要：
Yellow tea is a lightly fermented tea with unique sensory qualities and health benefits. However, chemical composition and sensory quality of yellow tea products have rarely been studied. 12 representative yellow teas, which were basically covered the main products of yellow tea, were chosen in this study. Combined analysis of non-targeted/targeted metabolomics and electronic sensor technologies (E-eye, E-nose, E-tongue) revealed the chemical and sensor variation. The results showed that yellow big tea differed greatly from yellow bud teas and yellow little teas, but yellow bud teas could not be effectively distinguished from yellow little teas based on chemical constituents and electronic sensory characteristics. Sensor variation of yellow teas might be attributed to some compounds related to bitterness and aftertaste-bitterness (4 '-dehydroxylated gallocatechin-3-O-gallate, dehydrotheasinensin C, myricitin 3-O-galactoside, phloroglucinol), aftertaste-astringency (methyl gallate, 1,5-digalloylglucose, 2,6-digalloylglucose), and sweetness (maltotriose). This study provided a comprehensive un-derstanding of yellow tea on chemical composition and sensory quality.
摘要：
Hopfield neural networks are favored by academia and industrial fields due to their abundant dynamics. In this paper, the dynamical behavior of a small Hopfield neural network (HNN) simultaneously stimulated by electromagnetic radiation and multi-level-logic pulse is investigated. Firstly, a modified HNN with three neurons is presented by selecting appropriate synapse weight coefficients. And the system model of the HNN under electromagnetic radiation and an electrical pulse is constructed. Then its equilibrium stabilities and nonlinear dynamical phenomena are analyzed by using numerical analysis methods including phase portraits, Lyapunov exponents, and bifurcation diagrams. The research results show that the neural network affected by electromagnetic radiation and a multi-level-logic pulse signal can generate chaotic multi-scroll attractors, which has not been observed in the previous investigation for the Hopfield-type neural networks. In addition, the number of the scroll can be easily changed by adjusting the electrical pulse signal. Circuit simulations based on the designed neural network circuit are carried out to confirm the numerical simulations. Finally, an HNN-based image encryption scheme is designed from the perspective of engineering applications. Performance evaluations demonstrate that the proposed image cryptosystem has good security.
摘要：
Our aim with this paper is to model and investigate the vibration and damping of a new hybrid composite shell. The considered composite cylindrical shell includes an FGM anisogrid lattice shell perfectly filled with viscoelastic foams. The modeling of the lattice part composed of spiral and hoop ribs is accomplished according to a global continuous standard based on orthotropic deep shells. The distribution pattern of the metal and ceramic constituents along the lattice ribs is specified by a power law. The homogenizations between ceramic and metal phases within the ribs, as well as between the FGM lattice structure and foam, are governed by the rule of mixtures. Based on the transferred Kelvin-Voigt viscoelastic scheme, the dynamic moduli of the foam portion are acquired. Because viscoelastic foam is a soft material, the higher-order shear deformation shell theory is used to estimate the system's displacement components. After emanating the dynamic equations by Hamilton's principle, the Chebyshev collocation-based semi-numerical method is implemented to detect the system's frequencies and loss factors. The comprehensive results show the role of each composite characteristic in the vibration and damping behavior of the defined structure.
期刊：
Reaction Kinetics, Mechanisms and Catalysis,2024年:1-12 ISSN：1878-5190
通讯作者：
Wang, JL
作者机构：
[Fang, Fang; Wang, Jiaoliang; Long, Liang; Wang, JL; Xia, Li; Liu, Zheng] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Wang, JL ] H;Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Chemical oscillating reactions;Dark tea;Uncatalyzed bromate oscillator;OKN mechanism
摘要：
A new kinetic study of the uncatalyzed bromate oscillator using dark tea without pre-treatment was carried out. The difference of dark tea oscillating system with and without manganese ion as catalyst was compared. The reaction was studied with different starting concentrations of the reagents (sulfuric acid and potassium bromate) and the substrate of dark tea, and the results indicate that the concentration of dark tea has a wide range between 1 with 30 g/L in dark tea-KBrO3-H2SO4 system, the lowest concentration of potassium bromate and sulfuric acid are 0.028 mol/L and 0.24 mol/L. The effects of the temperature were also investigated and the activation energy of oscillation was calculated to 88.78 kJ/mol. In addition, the possible mechanism of the non-catalyzed oscillating reaction was also discussed briefly.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2024年84(1):1-7 ISSN：1434-6044
通讯作者：
Chen, X
作者机构：
[Zhou, Jing] Hunan City Univ, Dept Phys, Yiyang 413000, Hunan, Peoples R China.;[Zhou, Jing] Hunan City Univ, All solid state Energy Storage Mat & Devices Key L, Yiyang 413000, Peoples R China.;[Zhou, Jing; Ping, Jialun] Nanjing Normal Univ, Dept Phys, Nanjing 210097, Jiangsu, Peoples R China.;[Chen, Jun] Hubei Minzu Univ, Dept Phys, Enshi 445000, Peoples R China.;[Zhang, Le] Hubei Normal Univ, Coll Phys & Elect Sci, Huangshi 435002, Peoples R China.
通讯机构：
[Chen, X ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
According to gauge/gravity correspondence, we study the holographic Schwinger effect within an anisotropic background. Firstly, the separate length of the particle-antiparticle pairs is computed within the context of an anisotropic background which is parameterized by dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document}. It is found that the maximum separate length x increases with the increase of dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document}. By analyzing the potential energy, we find that the potential barrier increases with the dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document} at a small separate distance. This observation implies that the Schwinger effect within an anisotropic background is comparatively weaker when contrasted with its manifestation in an isotropic background. Finally, we also find that the Schwinger effect in the transverse direction is weakened compared to the parallel direction in the anisotropic background, which is consistent with the top-down model.
摘要：
Fatigue driving is a serious threat to road safety, which is why accurately identifying fatigue driving behavior and warning drivers in time are of great significance in improving traffic safety. However, accurately recognizing fatigue driving is still challenging due to large intra-class variations in facial expression, continuity of behaviors, and illumination conditions. A fatigue driving recognition method based on feature parameter images and a residual Swin Transformer is proposed in this paper. First, the face region is detected through spatial pyramid pooling and a multi-scale feature output module. Then, a multi-scale facial landmark detector is used to locate 23 key points on the face. The aspect ratios of the eyes and mouth are calculated based on the coordinates of these key points, and a feature parameter matrix for fatigue driving recognition is obtained. Finally, the feature parameter matrix is converted into an image, and the residual Swin Transformer network is presented to recognize fatigue driving. Experimental results on the HNUFD dataset show that the proposed method achieves an accuracy of 96.512%, thus outperforming state-of-the-art methods.
摘要：
Purpose Co-composting with agriculture waste and sediment is an effective method to passivate the heavy metal content of sediment, but it is still unclear whether this passivation will be effective in the long term, and the contribution of different components of humic substances (HS) to the passivation of heavy metals has not been investigated quantitatively.Methods A 256-day composting experiment was conducted in 165 L reactors. Sediment, vegetables, rice straw, and bran were used as raw materials. Two experiments were set up, with pile A as control and pile B inoculated with Phanerochaete chrysosporium.Results The results revealed that the residual fraction of Cd (Res-Cd) increased by 24.22% and 27.04% in pile A and pile B, respectively. During the first 60 days of composting, the contents of humic acids-bound Cd (HA-Cd) both increased in two piles and accounted for 16.54% and 17.69% of the total content of Cd (T-Cd) in pile A and pile B, respectively. The correlation analysis suggested that the Res-Cd exhibited a significantly positive correlation with humic acid (HA) (P < 0.01) and HA-Cd, but a negative correlation with fulvic acid (FA) in both piles. Fourier-transform infrared spectroscopy and excitation-emission matrix fluorescence spectroscopy analysis demonstrated that the inoculation could enhance the chelating capability of HA to Cd and improve the maturity of compost.Conclusions This study has demonstrated that composting had a persistent passivation on Cd for 256 days. The contribution of HS to Cd passivation largely depends on the amount of HA-Cd rather than FA-Cd. Moreover, the inoculation of Phanerochaete chrysosporium could enhance the binding ability of HA to Cd and improve the maturity of compost.
期刊：
Bulletin of Engineering Geology and the Environment,2024年83(3):1-15 ISSN：1435-9529
通讯作者：
Hu, HX;Deng, C
作者机构：
[Xie, Zhongliang; Cai, Yuehui; Hu, Huanxiao; Lu, Yufan; Gan, Benqing] Minist Educ, Key Lab Metallogen Predict Nonferrous Met & Geol E, Changsha 410083, Peoples R China.;[Xie, Zhongliang; Cai, Yuehui; Hu, Huanxiao; Lu, Yufan; Gan, Benqing] Cent South Univ, Sch Geosci & Info Phys, Changsha 410083, Peoples R China.;[Deng, Chao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Deng, C ] H;[Hu, HX ] M;Minist Educ, Key Lab Metallogen Predict Nonferrous Met & Geol E, Changsha 410083, Peoples R China.;Cent South Univ, Sch Geosci & Info Phys, Changsha 410083, Peoples R China.;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.
摘要：
The grouting technique has been widely applied in geotechnical engineering. However, due to the concealed nature of underground engineering, there is relatively limited research on the diffusion characteristics of grout in sandy soil. This study utilized a self-developed three-dimensional grouting model test system. Experiments tests were conducted using standard sand and different water-cement (w/c) ratios of grout under limited boundary conditions, diffusion mechanism of sand soil grouting revealed. It was found that lower w/c ratios require higher grouting pressure when injecting grout into the sandy soil. The grouting pressure exhibited a pulsating pattern over time and a grouting pressure up to 323.9 kPa at w/c = 0.6. The grouting diffusion pattern under all w/c ratio conditions displayed typical columnar diffusion, and there was a good linear relationship between the average diffusion radius of the grout and the w/c ratio; the average diffusion radius was between 121 and 208 mm. The volume of the grout bulbs varied significantly at different w/c ratios, decreasing as the w/c ratio increased. With increased grouting pressure and w/c ratio, the dewatering effect during the grouting process became more pronounced, and the bleeding rate of the slurry with w/c = 1.4 (67.1%) is more than six times that of the w/c = 0.6 (10.5%). The results show that the uplift displacement on the soil surface exhibited certain hysteresis, and the grouting lifting process in sandy soil was divided into three stages: initial deformation, accelerated uplift, and stable uplift.
