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Airborne fungal communities are more susceptible to anthropogenic activities than bacteria

Journal of Environmental Sciences 2025年第3期149卷 564-573页

作者： Yuanyuan Pan Zhiwei Zuo Xueyun Huang Renguo Zhu School of Water Resources&Environmental Engineering East China University of TechnologyNanchang 330013China Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution East China University of TechnologyNanchang 330013China

Airborne microorganisms(AM)have significant environmental and health *** studies have been conducted to investigate the factors influencing the composition and diversity of ***,the knowledge of AM with anthropogenic activities has not reach a *** this study,we took advantage of the dramatic decline of outdoor anthropogenic activities resulting from COVID-19 lockdown to reveal their *** collected airborne particulate matter before and during the lockdown period in two *** results showed that it was fungal diversity and communities but not bacteria obviously different between pre-lockdownand lockdown samples,suggesting that airborne fungiwere more susceptible to anthropogenic activities than ***,after the implementation of lockdown,the co-occurrence networks of both bacterial and fungal community became more complex,whichmight be due to the variation of microbial ***,Mantel test and correlation analysis showed that air pollutants also partly contributed to microbial *** fungal community was more affected by air pollutants than bacterial ***,some human pathogens like Nigrospora and Arthrinium were negatively correlated with air ***,our study highlighted the more impacts of anthropogenic activities on airborne fungal community than bacterial community and advanced the understanding of associations between anthropogenic activities and AM.

关键词： COVID-19 lockdown Anthropogenic activities Airborne microorganisms Response Air pollutants

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Organic matter determines the exchange of nutrients at sediment-water interface in coastal bays

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Acta Oceanologica Sinica 2025年第1期44卷 72-85页

作者： Jiasen Zhong Ehui Tan Chunwei Fu Guiyi Ma Yongkai Chang Zhixiong Huang Jingchao Yin Fengying Li Jianzhong Su Min Xu Zhenzhen Zheng Jian’an Liu Yu Han Shuh-Ji Kao State Key Laboratory of Marine Resources Utilization in the South China Sea School of Ecology and Environment and School of Marine Science and EngineeringHainan UniversityHaikou 570228China Collaborative Innovation Center of Marine Science and Technology Hainan UniversityHaikou 570228China

The exchange of inorganic nutrients at the coastal sediment-water interface(SWI)plays a crucial role in regulating the nutrient budget in overlying *** related studies mainly focus on the mid-to high-latitude regions,leaving a significant gap in the quantitative assessment of nutrient exchange and environmental controls at the SWI in lowlatitude coastal *** quantitatively assess the exchange of inorganic nutrients at the SWI in three tropical bays(Dongzhai Harbor,Xiaohai Lagoon,Qinglan Harbor).Sediments act as a source of ammonium,phosphate,and silicate,but for nitrate,sediments can be both a source and sink,although with substantial spatial and temporal variations in their *** organic matter is a critical regulator for the fluxes of inorganic nutrients at the *** sedimentary nutrients input with high N/P molar ratio will alter the nutrient stoichiometry to mitigate the nitrogen limitation in coastal ***,the internal sediment release in these tropical bays plays a relative weak role in contributing to the nutrient addition in comparison with the other external nutrient sources including riverine input,submarine groundwater discharge,and atmospheric *** to the global compilation on SWI nutrient fluxes,we propose that water column primary production and external inputs to interpret the variation in exchange and fluxes of nutrients at the SWI in different *** a conceptual understanding of these chain biogeochemical processes involving external nutrient input,primary production,particulate organic matter settling,and the accumulation and release of inorganic nutrients in sediments will be helpful for the scientific-based pollution prevent and control in coastal waters.

关键词： tropical bay sediment-water interface nutrient exchange labile organic matter source/sink

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Study on Dry Electrical Discharge Assisted Grinding of SiCp/Al Composite

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Chinese Journal of Mechanical engineering 2025年第1期38卷 106-118页

作者： Yanjun Lu Yuming Huang Xiaobu Liu Rong Cheng Shunda Zhan Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China School of Intelligent Manufacturing and Equipment Shenzhen Institute of Information TechnologyShenzhen 518172China

SiC-reinforced aluminum matrix(SiCp/Al)composite is widely utilized in the aerospace,automotive,and electronics industries due to the combination of ceramic hardness and metal ***,the significant disparity in properties between SiC particles and the aluminum matrix results in severe tool wear and diminished surface quality during conventional *** study proposes an environmentally friendly and clean dry electrical discharge assisted grinding process as an efficient and low-damage machining method for SiCp/*** experimental platform was set up to study the impact of grinding and discharge process parameters on surface *** study compared the chip formation mechanism and surface quality between dry electrical discharge assisted grinding and conventional grinding,revealing relationships between surface roughness,grinding force,grinding temperature,and related *** results indicate that the proposed grinding method leads to smaller chip sizes,lower grinding forces and temperatures,and an average reduction of 19.2%in surface roughness compared to conventional *** axial,tangential,and normal grinding forces were reduced by roughly 10.5%,37.8%,and 23.0%,*** optimized process parameters were determined to be N=2500 r/min,vf=30 mm/min,a=10μm,E=15 V,f=5000 Hz,dc=80%,resulting in a surface roughness of 0.161μm.

关键词： Dry electrical discharge assisted grinding SiCp/Al composite Surface quality Grinding force Grinding temperature

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Performance Analysis of a Hexagon Rolling Mechanism with Single Degree of Freedom

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Journal of Mechanisms and Robotics 2025年第8期17卷 081001页

作者： Zhang, Qianqian Li, Yezhuo Yan, Shaoze Yao, Yan-An Department of Mechanical Engineering Tsinghua University Beijing100084 China School of Mechanical Electronic and Control Engineering Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control Technology Beijing Jiaotong University Beijing100044 China

This article presents a comprehensive performance analysis of the step-climbing and passive rolling modes of a hexagon rolling mechanism with single-degree-of-freedom, based on its structural characteristics and the constraints of centroid stability. First, a step-climbing model, incorporating motion parameters and support distance parameters, is established by leveraging the symmetrical posture movement characteristics of the hexagon rolling mechanism. Building on this foundation, the impact of each parameter on the mechanism's step-climbing ability is thoroughly analyzed, and the maximum height achievable during step climbing is also examined. Subsequently, the existence and sufficient conditions for the hexagon rolling mechanism to achieve passive rolling are analyzed using the centroid fluctuation curve and its slope curves. The analysis results indicate that, due to its unique coupling structure design, the hexagon rolling mechanism possesses a passive rolling capability that is not available in conventional planar linkage mechanisms. Finally, the correctness of the theoretical model is validated through both simulation and prototype experiments. Copyright © 2025 by ASME.

关键词： Degrees of freedom (mechanics)

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Advances in the chemical modification of nanocellulose for biodegradable plastics reinforcement

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International Journal of Agricultural and Biological engineering 2025年第1期18卷 10-24页

作者： Shuya Zhang Mingda Che Renliang Huang Mei Cui Wei Qi Rongxin Su State Key Laboratory of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Ningbo Key Laboratory of Green Petrochemical Carbon Emission Reduction Technology and Equipment Zhejiang Institute of Tianjin UniversityNingbo 315201ZhejiangChina Tianjin Key Laboratory for Marine Environmental Research and Service School of Marine Science and TechnologyTianjin UniversityTianjin 300072China Tianjin Sustainable Novel Materials Co.Ltd. Tianjin 300192China

As non-degradable traditional plastics contribute to environmental pollution,biodegradable polymers have been identified as a promising ***,inherent drawbacks such as low toughness,poor tensile strength,and reduced thermal degradation temperatures limit the further development of biodegradable *** has the potential to enhance the properties of biodegradable polymers without compromising their ***,the abundant hydroxyl groups in nanocellulose’s molecular chains result in poor compatibility with hydrophobic polymers,requiring surface modification prior to their *** review first introduces several common biodegradable polymers and three types of nanocellulose,followed by a comprehensive analysis of the recent advancements in the chemical modification methods of nanocellulose over the last five *** methods encompass esterification,oxidation,silylation,and graft *** focus of this discussion is primarily on the modification strategies,enhancement effects,and ***,the degradability and applications of modified nanocellulose composites are ***,the main challenges hindering the development of chemically modified nanocellulose-reinforced biodegradable polymers are *** is hoped that this review will inspire future researchers to develop industrially valuable chemically modified nanocellulose-reinforced biodegradable polymers.

关键词： biodegradable polymers nanocellulose surface modification reinforcement mechanisms degradability application

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An Improved Lightweight Safety Helmet Detection Algorithm for YOLOv8

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Computers, Materials & Continua 2025年第5期83卷 2245-2265页

作者： Lieping Zhang Hao Ma Jiancheng Huang Cui Zhang Xiaolin Gao Key Laboratory of AdvancedManufacturing and Automation Technology EducationDepartment of Guangxi Zhuang Autonomous RegionGuilin University of TechnologyGuilin541004China Guangxi Key Laboratory of Special Engineering Equipment and Control Guilin University of Aerospace TechnologyGuilin541004China Guangxi Tianli Construction Engineering Co. Ltd.Guilin541001China School of Information Engineering Nanning College of TechnologyGuilin541004China

Detecting individuals wearing safety helmets in complex environments faces several *** factors include limited detection accuracy and frequent missed or false ***,existing algorithms often have excessive parameter counts,complex network structures,and high computational *** challenges make it difficult to deploy such models efficiently on resource-constrained devices like embedded *** at this problem,this research proposes an optimized and lightweight solution called FGP-YOLOv8,an improved version of *** YOLOv8 backbone network is replaced with the FasterNet model to reduce parameters and computational demands while local convolution layers are *** modification minimizes computational costs with only a minor impact on accuracy.A new GSTA(GSConv-Triplet Attention)module is introduced to enhance feature fusion and reduce computational *** is achieved using attention weights generated from dimensional interactions within the feature ***,the ParNet-C2f module replaces the original C2f(CSP Bottleneck with 2 Convolutions)module,improving feature extraction for safety helmets of various shapes and *** CIoU(Complete-IoU)is replaced with the WIoU(Wise-IoU)to boost performance further,enhancing detection accuracy and generalization *** results validate the *** proposedmodel reduces the parameter count by 19.9% and the computational load by 18.5%.At the same time,mAP(mean average precision)increases by 2.3%,and precision improves by 1.2%.These results demonstrate the model’s robust performance in detecting safety helmets across diverse environments.

关键词： YOLO safety helmet detection complex environments lightweight WIoU loss function

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Evidence of microstructural evolution linked to non-monotonic distribution of micromechanical properties induced by shot peening

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材料科学技术（英文版） 2025年第4期207卷 238-245页

作者： Guoxin Lu Qiang Wang Bonnie Attard Huhu Su Shijian Zheng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationSchool of Materials Science and EngineeringShandong UniversityJinan250061China Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Material AECC Beijing Institute of Aeronautical MaterialsBeijing100095China Department of Metallurgy and Materials Engineering University of MaltaMSD2080Malta Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China

The residual stress field induced by surface strengthening processes such as mechanical shot peening and other forms of plastic deformation does not generally exhibit a simple"monotonic"distribution *** researchers have analyzed this fact from a mechanical perspective based on Hertz ***,the micro/nano-scale microstructural changes corresponding to the distribution of residual stress fields still appear to be *** this study,we focused on a widely used material in aviation manufacturing,namely nickel-based superalloy GH4169,as our experimental *** subjected GH4169 alloy to me-chanical strengthening treatment using a shot peening intensity of 0.25 mmA,followed by quantitative testing of micromechanical performance indicators such as microhardness and residual *** thor-oughly investigate the relationship between micromechanical properties and microstructure changes,we utilized transmission electron microscopy(TEM)to observe and analyze shot-peened materials at differ-ent *** findings revealed that the most severe microstructural distortion induced by mechanical shot peening in GH4169 alloy was likely to occur within a depth range of 25 to 75 *** observation aligns with the actual phenomenon that the maximum microhardness and maximum residual compres-sive stress did not manifest on the outermost surface of the *** presenting a detailed analysis of deformation defects such as dislocations,stacking faults,and twinning in different depths of mechan-ically strengthened layers,our study contributes to a deeper understanding and practical application of post-processing technologies based on plastic deformation.

关键词： Mechanical shot peening Surface strengthening Residual stress Microstructure

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Thickness Measurement of Single-Mode Fiber Coating Layer Based on Forward Brillouin Scattering

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IEEE Sensors Journal 2025年第11期25卷 19332-19340页

作者： Zhang, Yongqi Wang, Tao Liu, Yijia Liu, Li Zhang, Mingjiang Taiyuan University of Technology Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education College of Physics and Optoelectronic Engineering Taiyuan030024 China Taiyuan University of Technology Shanxi Key Laboratory of Precision Measurement Physics College of Physics and Optoelectronic Engineering Taiyuan030024 China

The coating layer is essential for protecting and applying optical fibers. Nowadays, the thickness measurement of the coating layer relies on point measurement schemes such as the side-looking light distribution method and mechanical method. However, there are some problems with the above methods, such as the trade-off between resolution and field of view, the cutting of the measurement position and the long measurement time. To overcome these problems, we propose a new method based on forward Brillouin scattering, which measures the coating layer thickness of single-mode fibers. The physical properties of the transverse acoustic field involved in forward Brillouin scattering make it possible to measure the thickness of the fiber coating. The corresponding relationship between the transverse acoustic mode frequency and the diameter of the coating layer can be calculated. The coating layer thickness can be measured with high precision by measuring the frequency spectrum of forward Brillouin scattering corresponding to multiple transverse acoustic modes at a given temperature. In the verification experiment, three types of single-mode fibers coated with polyimide are used as the sensing fiber to measure the thickness of the coating layer at multiple temperatures. The experimental results show that the error in the coating layer thickness obtained is less than 0.05 μm. To the best of our knowledge, this is the first demonstration of non-destructive, high-precision monitoring of fiber coating thickness. © 2001-2012 IEEE.

关键词： Acoustic field measurement

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D-FUSION SLAM: A VSLAM SYSTEM OPTIMIZED BY INTEGRATING DEPTH INFORMATION AND RGBD FEATURE POINTS

UPB Scientific Bulletin, Series C: Electrical Engineering an...

引用

UPB Scientific Bulletin, Series C: Electrical engineering and Computer Science 2025年第1期87卷 121-138页

作者： Zheng, Qingchun Wu, Moudong Zhu, Peihao Yang, Bin Li, Shubo Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China China

This paper introduces D-Fusion SLAM, an advanced VSLAM system based on ORB-SLAM2. D-Fusion SLAM integrates depth information to enhance feature selection, aiming to improve accuracy and speed in visual SLAM applications. The system mainly comprises two modules: an image grid filtering module based on grayscale information and a feature selection module integrating depth information. These modules effectively eliminate redundant and useless features, ensuring high-quality features for pose estimation. We tested D-Fusion SLAM on the TUM dataset and compared it with ORB-SLAM2. Experimental results demonstrate that D-Fusion SLAM outperforms ORB-SLAM2, significantly enhancing the system's accuracy and robustness. © 2025, Politechnica University of Bucharest. All rights reserved.

关键词： Feature Selection

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Linear active disturbance rejection control of fighter aircraft based on MADDPG algorithm

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International Journal of Systems, control and Communications 2025年第2期16卷 152-172页

作者： Lin, Yetong Ji, Yuehui Song, Yu Liu, Junjie Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry Systems School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China

To address nonlinearity, strong coupling, and disturbances in fighter aircraft attitude control, this paper proposes an intelligent control method based on multi-agent deep deterministic policy gradient (MADDPG) and linear active disturbance rejection control (LADRC). A three-channel LADRC controller estimates and compensates for disturbances, uncertainties, and coupling terms in real time. To overcome the dimensionality curse in multi-parameter optimization, an independent DDPG controller is assigned to each channel, ensuring cooperative control via reward sharing and enhancing dynamic response and disturbance rejection. Additionally, long short-term memory (LSTM) and self-attention mechanisms are integrated into the policy and value networks to improve representation and decision-making. A piecewise combined reward function mitigates sparse rewards. Simulations show that, compared to MADQN-based and traditional LADRC methods, the proposed approach achieves superior control performance and significantly reduces manual parameter tuning efforts. Copyright © 2025 Inderscience Enterprises Ltd.

关键词： Disturbance rejection

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