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:
Wan Dai;Guoping Qian;Xuan Zhu;Huanan Yu*;Changyun Shi;...
期刊:
Construction and Building Materials,2024年416:135069 ISSN:0950-0618
通讯作者:
Huanan Yu
作者机构:
[Wan Dai; Changyun Shi; Chao Zhang; Jinguo Ge; Tangxin Xie] School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China;Xiangjiang Laboratory, Changsha 410205, China;National Engineering Research Center of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, China;School of Civil Engineering, Hunan City University, Yiyang 413000, China;[Guoping Qian; Huanan Yu] School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Xiangjiang Laboratory, Changsha 410205, China<&wdkj&>National Engineering Research Center of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, China
通讯机构:
[Huanan Yu] S;School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Xiangjiang Laboratory, Changsha 410205, China<&wdkj&>National Engineering Research Center of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, China
摘要:
Void is an important manifestation of the strength of asphalt mixture, but few studies have focused on the change of voids during the compaction of asphalt mixtures. The voids of SMA-13 and OGFC-13 were selected as the research objects, and the compaction process of the asphalt mixture was analyzed based on different compaction degree specimens in lab through gyratory compactor. Firstly, CT scanning was used to extract the void structure of the asphalt mixture at different degrees. Secondly, based on the 26-connectivity algorithm, the connected voids and closed voids of asphalt mixture were extracted, and the volume and particle size distribution were analyzed. Thirdly, the gradation of voids was analyzed by the two-parameter Weibull function, and the morphological characteristics of voids were analyzed by roundness, sphericity, and abundance. The results showed that the distribution of cross-section voids ratio and the number of voids of the SMA-13 was more uniform than that of OGFC-13. The characteristic parameters of two-parameter Weibull function showed that with the increase of specimen density, the three-dimensional void size became smaller and smaller, and the void size distribution became more and more uniform. The sphericity and roundness of the voids of SMA-13 and OGFC-13 were less affected by the compaction degree, and the void abundance of the OGFC-13 gradation asphalt mixture was greatly affected. For the connectivity of voids, the closed void volume of OGFC-13 increased with the increase of compaction degree, but the maximum proportion of closed voids in the total void volume does not exceed 10% during the compaction process. For the gradation SMA-13, the compaction degree of 90%∼93% was the boundary interval of connected voids from existence to nonexistence, which may be a critical interval for forming skeleton strength during the compaction process.
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.
期刊:
FRONTIERS IN PSYCHOLOGY,2024年15:1349880 ISSN:1664-1078
作者机构:
Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China;Shenzhen Technology University, Shenzhen, Guangdong, China;Hunan City University, Yiyang, China
摘要:
Background: Physical activity significantly influences health-related behaviors, encompassing physical and mental well-being. Physical activity has been linked to enhancing health behavior, mental health, and psychological resilience. The current study is based on participants who were active in physical activity to improve health and well-being. Objectives: To examine the influences of physical activity on health behavior, mental health, and psychological resilience, considering the moderating role of quality of life. Method: A thorough cross-sectional online survey was conducted from April 15, 2023, to October 15, 2023. The survey was comprehensive and lasted for six months. The online poll received more than one thousand responses under convenience sampling. The selection criteria for the study were above 21 years old, and participants were active in physical activity to improve health and well-being. The collected data were analyzed using appropriate statistical SPSS-25 and SmartPLS 4.0 software to investigate the proposed research paradigm. Results: SEM results of model 1 (direct coefficients) show that PA has a positive effect on HeB, MeH, PsR, HeB on MeH, HeB on PsR. Out of six (in model 2, four moderating effects of QOL were significant, and two were statistically insignificant. Conclusion: It has been observed that the quality of life has a moderating role in the relationships between physical exercise and several aspects, such as psychological resilience, mental health, and health-related behavior. It is imperative to emphasize the importance of fostering consistent engagement in physical activity to cultivate a well-balanced and health-conscious way of life.
作者机构:
[Zhengyang Li; Zhengdong Luo] College of Civil Engineering, Xiangtan University, Xiangtan 411105, China;Authors to whom correspondence should be addressed.;[Huichen Yang] China Institute of Water Resources and Hydropower Research, Beijing 100041, China;[Genbao Zhang] College of Civil Engineering, Hunan City University, Yiyang 413000, China;[Kun Liu] Hunan Zhitong Expressway Construction and Development Co., Ltd., Changsha 410026, China
通讯机构:
[Benben Zhang; Yufei Zhao] A;Authors to whom correspondence should be addressed.<&wdkj&>China Institute of Water Resources and Hydropower Research, Beijing 100041, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>School of Transportation, Southeast University, Nanjing 211189, China
关键词:
interfacial behavior;slag;fly ash and red mud;geopolymer mortar;concrete substrate;mechanical properties
摘要:
Geopolymer, as a new type of solid waste-based inorganic cementitious material, exhibits outstanding behavior in terms of physical and chemical performance, macromechanical properties, long-lasting stability, and features potential application development tendency in the field of repair and reinforcement of existing concrete structures. This paper investigated the interfacial behavior of geopolymer mortar with OPC concrete substrate under different slag, fly ash and red mud mixing proportions, while cement mortar was used as a control group for the research. The interfacial bonding properties of the geopolymer mortar to the OPC concrete substrate were elaborated by carrying out split tensile test, double-sided shear test, and three-point bending test. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to further analyze the microstructural characteristics and physical phase components of the interfacial transition zone between the geopolymer mortar and the OPC concrete substrate. The results indicated that the compressive strength of slag-fly ash-red mud-based geopolymer mortar under different mixing ratio conditions was consistently superior to that of cement mortar, where the optimum mixing ratio for the geopolymer mortar was S33F33R33. Overall, the interfacial bonding properties of the geopolymer mortar to the OPC concrete substrate gradually increased with the increment of the slag content, however, an evolutionary trend of minor enhancement followed by a gradual reduction was observed with the growth of the fly ash and red mud content.
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:
International Journal of Sustainable Development,2024年27(1-2):156-169 ISSN:0960-1406
作者机构:
1. College of Management, Hunan City University, Yiyang, 413000, China
关键词:
Monte Carlo algorithm;logistics enterprises;supply chain operation risk;relationship network;factor set
摘要:
Aiming at the problems of low evaluation accuracy and long evaluation time in the supply chain operation risk evaluation of logistics enterprises, a method of supply chain operation risk evaluation of logistics enterprises based on the Monte Carlo algorithm is designed. First, set up the screening process of logistics enterprise supply chain operation risk evaluation indicators, and determine the key risk evaluation indicators. Then, the relationship network of risk evaluation indicators is constructed and the evaluation indicators are pretreated. Finally, the reliability degree of the index is calculated by the joint probability distribution function, and the construction of the supply chain operation risk evaluation model of logistics enterprises based on the Monte Carlo algorithm is completed. The test results show that the evaluation accuracy of the proposed method is always higher than 98%, and the time cost is always lower than 2 s, which can effectively improve the evaluation accuracy and shorten the evaluation time.
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:
Science of The Total Environment,2024年920:170803 ISSN:0048-9697
通讯作者:
Chen, Yaoning;Li, Yuanping
作者机构:
[Zhao, Mengyang; Zhou, Wencheng; Zhao, Chen; Liu, Yihuan; Kang, Huayue; Chen, Li; Jiang, Hongjuan] College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China;[Chen, Yaoning] College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address: cyn@hnu.edu.cn;[Li, Yuanping] School of Municipal and Geomatics Engineering, Hunan City University, Yiyang 413000, China. Electronic address: yuanpingli@hncu.edu.cn;[Li, Hui] State Key Laboratory of Utilization of Woody Oil Resource and Institute of Biological and Environmental Engineering, Hunan Academy of Forestry, Changsha 410004, China
通讯机构:
[Chen, Yaoning] C;[Li, Yuanping] S;College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address:;School of Municipal and Geomatics Engineering, Hunan City University, Yiyang 413000, China. Electronic address:
摘要:
Novel tourmaline-biochar composites (TBs) were synthesized by introducing tourmaline (TM) into pomelo peel biochar (BC). The surface properties of TBs and BC were studied and the adsorption performances for Pb(2+) were investigated. Compared to pristine BC, the adsorption ability for Pb(2+) on TBs was enhanced with the increase of TM in TBs, and up to 514.62mg/g on 5%TB. The enrichment of inorganic metals caused by TM in TBs made the precipitation and cation ion exchange become the main mechanisms in adsorbing Pb(2+), and the amounts of adsorbing Pb(2+) by those two mechanisms on TBs were 1.10-1.48 times and 1.20-1.30 times those of BC, respectively. Furthermore, applying TBs to practical contaminated soil increased the soil pH and electrical conductivity (EC) after 15days of incubation. The increased content of residual-Pb and reduced exchangeable-Pb and DTPA-Pb indicated that TBs were favorable for the immobilization of Pb in soil. This study gives a new perspective on the synthesis of tourmaline-biochar composite and their application in Pb-polluted water and soil.
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.
期刊:
Frontiers in Marine Science,2024年11:1336783 ISSN:2296-7745
作者机构:
Yantai Research Institute, Harbin Engineering University, Harbin, 150001, Heilongjiang Province, China;Hunan City University, Yiyang, China
关键词:
Floating photovoltaic;offshore;Marine environment protection;Technological feasibility;life cycle of photovoltaic;potential impacts
摘要:
The development of solar energy is one of the most effective means to deal with the environmental and energy crisis. The floating photovoltaic (PV) system is an attractive type because of its multiple advantages and has been well developed based on fresh water areas on land. This paper focuses on the expansion of this sector towards the ocean, offshore floating PV plants, which is the new growth point with huge potential for the future PV sector. For this new field, the technology readiness level is really low and research to understand the interaction between offshore floating PV plants and marine environment are proceeding. In this paper, we aim to discuss the technological feasibility of offshore floating PV plants as well as analyze potential impacts on the marine environment during the life cycle of PV from manufacturing until disposal.
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.
期刊:
Science of The Total Environment,2024年924:171600 ISSN:0048-9697
通讯作者:
Chen, Yaoning;Li, Yuanping
作者机构:
[Chen, Yaoning] College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address: cyn@hnu.edu.cn;[Yuan, Yu; Wang, Qianruyu; Luo, Mengwei; Wang, Jun; Chen, Li; Jiang, Hongjuan] College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China;[Li, Yuanping] School of Municipal and Geomatics Engineering, Hunan City University, Yiyang, Hunan 413000, China. Electronic address: yuanpingli@hncu.edu.cn;[Li, Hui] State Key Laboratory of Utilization of Woody Oil Resource and Institute of Biological and Environmental Engineering, Hunan Academy of Forestry, Changsha 410004, China;[Chen, Yanrong] School of Resource & Environment, Hunan University of Technology and Business, Changsha 410205, China
通讯机构:
[Chen, Yaoning] C;[Li, Yuanping] S;College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address:;School of Municipal and Geomatics Engineering, Hunan City University, Yiyang, Hunan 413000, China. Electronic address:
摘要:
The electric field-assisted composting system (EACS) is an emerging technology that can enhance composting efficiency, but little attention has been given to electrode materials. Herein, an EACS was established to investigate the effects of electrode materials on humic substance formation and heavy metal speciation. Excitation-emission matrix analysis showed that carbon-felt and stainless-steel electrodes increased humic acid (HA) by 48.57% and 47.53%, respectively. In the EACS with the carbon-felt electrode, the bioavailability factors (BF) of Cu and Cr decreased by 18.00% and 7.61%, respectively. Despite that the stainless-steel electrodes decreased the BF of As by 11.26%, the leaching of Cr, Ni, Cu, and Fe from the electrode itself is an inevitable concern. Microbial community analyses indicated that the electric field increased the abundance of Actinobacteria and stimulated the multiplication of heavy metal-tolerant bacteria. Redundancy analysis indicates that OM, pH, and current significantly affect the evolution of heavy metal speciation in the EACS. This study first evaluated the metal leaching risk of stainless-steel electrode, and confirmed that carbon-felt electrode is environment-friendly material with high performance and low risk in future research with EACS.