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Multiscale causes of the 2022 Yangtze mega-flash drought under climate change

Science China Earth Sciences 2024年第8期67卷 2649-2660页

作者： xing YUAN Yumiao WANG Shiyu ZHOU hua LI Chenyuan LI School of Hydrology and Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China

The 2022 Yangtze mega-flash drought is characterized by strong intensity and rapid development both in time and space,accompanied by a persistent anticyclonic circulation ***,the causes of the extreme event remain elusive given the multiscale nature of *** we presented a brief overview for the oceanic and terrestrial causes of the megaflash drought during the summer of 2022,and estimated the risk in a changing *** the soil moisture percentile as the drought index,it was found that the drought expanded to the entire Yangtze River basin within two months,with 80%of basin under severe drought conditions at the end of *** the intensity and onset speed of the 2022 mega-flash drought were ranked as the first during the past 62 years,with return periods of 86 and 259 years,*** results of composite analysis showed that the spring La Ni?a can facilitate the abrupt change from a wet/normal condition in May–June to drought in July–August over the Yangtze River basin,which was beneficial for the increase of flash drought intensity and onset speed *** analysis through the linear regression also indicated that the unprecedented intensity was associated with the negative phase of the Pacific Decadal *** by a coupling strength index for soil moisture and vapor pressure deficit,it was found that there was a strong land-atmosphere coupling over the Yangtze River basin during July–August *** attribution by using CMIP6 climate models suggested that land-atmosphere coupling increased the risks of flash drought intensity and onset speed like 2022 by 61%±6%and 64%±7%under natural climate forcings,and the synergy of coupling and anthropogenic climate change would increase the risks by 75%±22%and 85%±12%.Our findings emphasized the role of landatmosphere coupling combined with anthropogenic climate change in intensifying flash droughts.

关键词： Flash drought Yangtze River basin Land-atmosphere coupling Climate change Attribution

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Collective Movement Simulation:Methods and Applications

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Machine Intelligence Research 2024年第3期21卷 452-480页

作者： hua Wang xing-Yu Guo Hao Tao Ming-Liang Xu School of Computer and Artificial Intelligence Zhengzhou UniversityZhengzhou450001China Engineering Research Center of Intelligent Swarm Systems Ministry of EducationZhengzhou450001China National Supercomputing Center in Zhengzhou Zhengzhou450001China China Ship Development and Design Center Wuhan430060China

Collective movement simulations are challenging and important in many areas,including life science,mathematics,physics,information science and public *** this survey,we provide a comprehensive review of the state-of-the-art techniques for collective movement *** start with a discussion on certain concepts to help beginners understand it more ***,we analyze the intelligence among different collective objects and the emphasis in different ***,we classify existing collective movement simulation methods into four categories according to their effects,namely versatility,accuracy,dynamic adaptability,and assessment feedback ***,we introduce five applications of layout optimization,emergency control,dispatching,unmanned systems,and other derivative ***,we summarize possible future research directions.

关键词： Collective movement simulation multiple objects multiple discipline simulation effect collective intelligence

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Atomic force microscopy-based nanoscale infrared techniques for liquid environments

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Science Bulletin 2024年第2期69卷 151-153页

作者： Jian Li Jing Liang Mu-Hao Lan xing-hua Xia State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Infrared(IR)light energy matches well with the vibration and rotation of chemical bonds in molecules,hence IR spectroscopy is commonly used for accurate molecular identification[1].Conventional IR analysis involves bulk samples,providing averaged information of the entire *** spatially-resolved investigation of heterogeneous sample properties is constrained by the micrometer-level spatial resolution of optical IR microscopy.

关键词： spatially hence rotation

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Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content

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Petroleum Science 2024年第2期21卷 855-865页

作者： Jian-Yong Xie Yan-Ping Fang xing-hua Wu Jian'er Zhao Jun-Cheng Dai Jun-xing Cao Ji-Xin Deng State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina Key Lab of Earth Exploration&Information Techniques of Ministry of Education Geophysical InstituteChengdu University of TechnologyChengdu610059SichuanChina PetroChina Southwest Oil&Gasfield Company Chengdu610017SichuanChina

Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(KC)is of great significance in hydrocarbon exploration and *** controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore *** employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying *** artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different *** revealed bedding perpendicular P-wave velocities are more sensitive to the increasing KC than bedding paralleling velocities due to the preferential alignments of *** elastic stiffnesses except C_(13.are generally decreasing with the increasing KC,the variation of C_(1) and C_(3.)on kerogen content are more sensitive than those of C_(44)and C_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of KC,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing KC,withΔB showing great sensitivity to KC *** the range of low KC(10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of KC in shales.

关键词： Elastic properties Organic shale Anisotropy Kerogen content Physical modeling

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Microphase Separation of Semiflexible Ring Diblock Copolymers

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Chinese Journal of Polymer Science 2024年第2期42卷 267-276,I0011页

作者： Dan-Yan Qin Sheng-Da Zhao Zhi-Xin Liu Jing Zhang xing-hua Zhang School of Physical Science and Engineering Beijing Jiaotong UniversityBeijing100044China

Aiming at the difficult problem of solving the conformation statistics of complex polymers, this study presents a novel and concise conformation statistics theoretical approach based on Monte Carlo and Neural Network method. This method offers a new research idea for investigating the conformation statistics of complex polymers, characterized by its simplicity and practicality. It can be applied to more complex topological structure, more higher degree of freedom polymer systems with higher dimensions, theory research on dynamic self-consistent field theory and polymer field theory, as well as the analysis of scattering experimental data. The conformation statistics of complex polymers determine the structure and response properties of the system. Using the new method proposed in this study, taking the semiflexible ring diblock copolymer as an example, Monte Carlo simulation is used to sample this ring conformation to construct the dataset of polymer. The structure factor describing conformation statistics are expressed as continuous functions of structure parameters by neural network supervised learning. This is the innovation of this work. As an application, the structure factors represented by neural networks were introduced into the random phase approximation theory to study the microphase separation of semiflexible ring diblock copolymers. The influence of the ring's topological properties on the phase transition behavior was pointed out.

关键词： Ring copolymer Diblock copolymers Semiflexible The order-disorder transition

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Selective and asymmetric ion transport in covalent organic framework-based two-dimensional nanofluidic devices

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International Journal of Smart and Nano Materials 2024年第1期15卷 186-197页

作者： Li-Qiu huang Shuang Chen Ri-Jian Mo Zhong-Qiu Li xing-hua Xia State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjingChina

Two-dimensional(2D)covalent organic framework(COF)mem-branes featuring well-aligned and programmable vertical nano-channels have emerged as a promising candidate for advanced nanofluidic devices and showcased vast potential in the fields of smart-gating,ion-separation,and ***,the transverse interlayer nanochannels with a height of sub-nanometer-scale in 2D-COF membranes have scarcely been studied in ***,we report the ion transport characteristics in 2D interlayer nanochannels of protonated CoF *** dis-tinct surface-charge-governed ionic conductance in domination of electrolyte concentration below 1o-3.M as well as the exceptional anion/cation(Cl^(-)/K^(+))selectivity is revealed due to the pronounced charge and nano-confinement ***,evident ion current rectification is witnessed when incorporating asymmetric geometry into the system,which is attributed to the dynamic process of ion enrichment and dissipation within the protonated *** work offers immense prospects for 2D-COF membranes in the fields of biomimetic nanofluidic devices and cutting-edge electronic devices.

关键词： Two-dimensional covalent organic framework interlayernanochannels ion transport characteristics nanofluidic device

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Nano polystyrene microplastics could accumulate in Nile tilapia(Oreochromis niloticus):Negatively impacts on the intestinal and liver health through water exposure

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Journal of Environmental Sciences 2024年第3期137卷 604-614页

作者： Di Wu xing Lu Li-Xue Dong Juan Tian Jin Deng Lei Wei hua Wen Shan Zhong Ming Jiang School of Basic Medical Sciences Wuhan UniversityWuhan 430071China Key Laboratory of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural AffairsYangtze River Fisheries Research InstituteChinese Academy of Fishery SciencesWuhan 430223China Hubei Province Key Laboratory of Allergy and Immunology Wuhan 430071China

Microplastics(MPs)have become a significant concern for their potential ***,the correlation between the size of plastic particles and their toxicity remains ***,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm *** U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm *** gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm *** analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm *** conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver *** the above lay the foundation for further study on the pathological damage of MPs to other organisms.

关键词： Microplastics(MPs) Intestinal toxicity Liver toxicity Gut microbiome Lipid metabolism

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Photocatalytic applications and modification methods of two-dimensional nanomaterials:a review

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Tungsten 2024年第1期6卷 77-113页

作者： Fan Yang Ping Hu Fan Yang xing-Jiang hua Bo Chen Lili Gao Kuai-She Wang School of Metallurgy Engineering Xi’an University of Architecture and TechnologyXi’an 710055China National and Local Joint Engineering Research Center for Functional Materials Processing Xi’an University of Architecture and TechnologyXi’an 710055China

Due to its unique electronic structure and special size effect,two-dimensional(2D)nanomaterials have shown great potential far beyond bulk materials in the field of *** to deeply explore the photocatalytic mechanism of 2D nanomaterials and design more efficient 2D semiconductor photocatalysts are research *** review provides a comprehensive introduction to typical 2D nanomaterials and discusses their current application status in the field of *** effects of material properties such as band structure,morphology,crystal face structure,crystal structure and surface defects on the photocatalytic process are *** main modification methods are highlighted,including doping,noble metal deposition,heterojunction,thickness adjustment,defect engineering,and dye sensitization in 2D material ***,the future development of 2D nanomaterials is *** is hoped that this paper can provide systematic and useful information for researchers engaged in the field of photocatalysis.

关键词： Photocatalysis Two-dimensional Nanomaterials Bandgap Modification strategy

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A novel approach based on a modified mask R-CNN for the weight prediction of live pigs

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Artificial Intelligence in Agriculture 2024年第2期12卷 19-28页

作者： Chuanqi Xie Yuji Cang Xizhong Lou hua Xiao xing Xu Xiangjun Li Weidong Zhou State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products Institute of Animal Husbandry and Veterinary ScienceZhejiang Academy of Agricultural SciencesHangzhou 310021China College of Information Engineering China Jiliang UniversityHangzhou 310018China College of Hydraulic Engineering Zhejiang Tongji Vocational College of Science and TechnologyHangzhou 311231China

Since determining the weight of pigs during large-scale breeding and production is challenging,using non-contact estimation methods is *** study proposed a novel pig weight prediction method based on a mod-ified mask region-convolutional neural network(mask R-CNN).The modified approach used ResNeSt as the backbone feature extraction network to enhance the image feature extraction *** feature pyramid net-work(FPN)was added to the backbone feature extraction network for multi-scale feature *** channel at-tention mechanism(CAM)and spatial attention mechanism(SAM)were introduced in the region proposal network(RPN)for the adaptive integration of local features and their global dependencies to capture global in-formation,ultimately improving image segmentation *** modified network obtained a precision rate(P),recall rate(R),and mean average precision(MAP)of 90.3.%,89.85%,and 95.21%,respectively,effectively segmenting the pig regions in the *** image features,namely the back area,body length,body width,average depth,and eccentricity,were *** pig depth images were used to build five regression algo-rithms(ordinary least squares(OLS),AdaBoost,CatBoost,XGBoost,and random forest(RF))for weight value *** achieved the best prediction result with a coefficient of determination(R^(2))of 0.987,a mean absolute error(MAE)of 2.96 kg,a mean square error(MSE)of 12.87 kg^(2),and a mean absolute percentage error(MAPE)of 8.45%.The results demonstrated that the machine learning models effectively predicted the weight values of the pigs,providing technical support for intelligent pig farm management.

关键词： Deep learning Modified mask R-CNN Image processing Pig weight Prediction

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Mechanical performance of 22SiMn2TiB steel welded with lowtransformation- temperature filler wire and stainless steel filler wire

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Journal of Iron and Steel Research International 2024年第4期31卷 967-981页

作者： Zi-dong Lin Kai-jie Song Zhen Sun Zi-qian Zhu Xue-feng Zhao Constantinos Goulas Wei Ya xing-hua Yu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Department of Design Production and Management Faculty of Engineering Technology.University of TwenteEnschede 7500 AETheNetherlands Rotterdam Additive Manufacture Fieldlab(RAMLAB) Rotterdam 3089 JWTheNetherlands

TX-80 low-transformation-temperature(LTT)welding wire was used to replace the traditional ER 3.7Si welding wire to realize the connection of 22SiMn2TiB armor steel in manual overlay *** previously existing issues,such as welding cracks,large welding deformation,and severe welding residual stress,were solved to ensure good strength and ductility *** particular,with the same welding conditions,TX-80 LTT wire eliminates welding *** reduces the welding deformation no matter the base pretreatment of pre-setting angle or no pre-setting *** comparison,it was found that the microstructure at the TX-80 weld is mainly composed of martensite and a small amount of retained *** contrast,the microstructure of the ER 3.7Si weld consists of a large amount of austenite and a small amount of skeleton-like *** variation trend of residual stress and microhardness from the weld to the base were investigated and compared with the mechanical properties of base *** TX-80 and the ER 3.7Si tensile samples elongation is 6.76%and 6.01%,while the ultimate tensile strengths are 877 and 667 MPa,*** average impact toughness at room temperature of the ER 3.7Si weld is 143.9 J/cm^(2),much higher than that of the TX-80 weld,which is only 3..7 J/cm^(2).The relationship between impact and tensile properties with microstructure species and distribution was *** addition,the fracture surface of the tensile and the impact samples was observed and *** dimples,fewer pores,larger radiation zone,and shear lips of TX-80 samples indicate better tensile ductility and worse impact toughness than those of ER 3.7Si weld.

关键词： Low-transformation-temperature material 22SiMn2TiB steel Welding deformation Residual stress Martensitic transformation Mechanical property

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