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Changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

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Advances in Climate Change Research 2024年第2期15卷 265-274页

作者： yong YANG Ren-Sheng CHEN yong-Jian DING hong-Yuan LI Zhang-Wen LIU Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different ***,the changes in land surface freeze-thaw processes under climate change on a global scale are still *** on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to *** results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,*** FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to *** annual FG areas in the NH,SH,and globe all show significant decreasing trends(p<0.05)from 1950 to 2020 at-0.32×10^(6),-0.22×10^(6),and-0.54×10^(6)km^(2)per decade,*** FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD *** prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming

Influence of Heat-setting Temperature on the Microporous Structure and Properties of PP/HDPE Bilayer Microporous Membranes

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Chinese Journal of Polymer Science 2024年第8期42卷 1243-1252页

作者： Jie Xie yong-Shi Wu Jia-Yi Xie Rui-Jie Xu Cai-hong Lei Sai-Nan Song Guang-Quan Li An-Ping huang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Lanzhou Petrochemical Research Center Petrochemical Research InsititutePetroChinaLanzhou 730060China School of Chemistry and Civil Engineering Shaoguan CollegeShaoguan 512005China

Due to the mechanical stability of PP layer,the PP/HDPE double-layer microporous mem brane could be prepared at a higher heat-setting temperatu re than that of PE monolayer *** this work,the effects of heat-setting temperature on the pore structure and properties of PP/HDPE dou ble-layer membrane were *** the increase of heat-setting temperature from 120℃to 130℃,the length of connecting bridge crystal and crystallinity in the PE layer increase due to the melting of thin lamellae and the stability of connecting bridge structure during *** corresponding air permeability,po rosity,wetta bility of liquid electrolyte and mechanical property of the heat-set microporous membrane increase,exhibiting better electrochemical ***,when the heat-setting temperature is further increased to 140℃,higher than the melting point of PE resin,some pores are closed since the lamellae and connecting bridges melt and shrink during heat-setting,resulting in a decrease of air permeability and *** contrast,there is negligible change in the PP layer within the above heat-setting temperature *** study successfully builds the relationship between the stable pore structure and property of microporous membrane during heat-setting,which is helpful to guide the production of high-pe rformance PP/PE/PP lithium batteries separator.

关键词： PP/HDPE bilayer microporous membranes Heat-setting temperature SAXS

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： yong-Chao Li Rui-Sheng Jia Ying-Xiang Hu hong-Mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning

XGCN:a library for large-scale graph neural network recommendations

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Frontiers of Computer Science 2024年第3期18卷 247-249页

作者： Xiran SONG hong huang Jianxun LIAN Hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System LabCluster and Grid Computing LabSchool of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China Microsoft Research Asia Beijing 100080China

1 Introduction Graph Neural Networks(GNNs)have gained widespread adoption in recommendation systems,and nowadays there is a pressing need to effectively manage large-scale graph data[1].When it comes to large graphs,GNNs may encounter the scalability issue stemming from their multi-layer messagepassing ***,scaling GNNs has emerged as a crucial research area in recent years,with numerous scaling strategies being proposed.

关键词： scaling gained operations

Microstructure evolution of Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)amorphous alloy after semi-solid isothermal treatment

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China Foundry 2024年第3期21卷 287-294页

作者： Xin-hua huang Jing-wen Pu yong-xin Luo Yue-jun Ouyang School of Material Electricity and Intelligent ManufacturingHuaihua UniversityHuaihua 330031HunanChina Hunan Renewable Aluminum Innovation Research Center Huaihua UniversityHuaihua 330031HunanChina

The as-cast amorphous Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)composites,comprising in situ formedβ-Ti ductile crystalline precipitates,were prepared by water cooled copper mold suction ***,the semi-solid composites were obtained after the as-cast composites were treated by semi-solid isothermal *** microstructure evolution and kinetics of the composites were *** show that the microstructures of both the as-cast and semi-solid composites comprise ofβ-Ti crystal phases and amorphous matrix *** and after treatment,the crystals evolve from fine granular or fine dendritic crystals to coarse *** the treatment temperature increasing or the time prolonging,the average crystal size gradually increases and the surface morphology of the crystals gradually becomes *** studying the microstructural evolution and dynamics during the isothermal treatment process,it is found that the final morphology ofβ-Ti crystals is influenced by the isothermal treatment temperature and time(t),and theβ-Ti evolution rate increases with an increase in treatment *** addition,a linear relationship was observed between the size of cubicβ-Ti crystals(D^(3))and t;the growth kinetics factor K is 3.8μm^(3)·s^(-1).As the K value closes to 4μm^(3)·s^(-1),it is inferred the morphology evolution ofβ-Ti crystals is a coarsening behavior controlled by the diffusion of solute elements.

关键词： Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14) amorphous matrix composites semi-solid as-cast microstructure

Mechanism of internal thermal runaway propagation in blade batteries

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Journal of Energy Chemistry 2024年第2期89卷 184-194,I0005页

作者： Xuning Feng Fangshu Zhang Wensheng huang yong Peng Chengshan Xu Minggao Ouyang School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China

Blade batteries are extensively used in electric vehicles,but unavoidable thermal runaway is an inherent threat to their safe *** study experimentally investigated the mechanism underlying thermal runaway propagation within a blade battery by using a nail to trigger thermal runaway and thermocouples to track its propagation inside a *** results showed that the internal thermal runaway could propagate for up to 272 s,which is comparable to that of a traditional battery *** velocity of the thermal runaway propagation fluctuated between 1 and 8 mm s^(-1),depending on both the electrolyte content and high-temperature gas *** the early stages of thermal runaway,the electrolyte participated in the reaction,which intensified the thermal runaway and accelerated its *** the battery temperature increased,the electrolyte evaporated,which attenuated the acceleration *** diffusion affected thermal runaway propagation through both heat transfer and mass *** experimental results indicated that gas diffusion accelerated the velocity of thermal runaway propagation by 36.84%.We used a 1D mathematical model and confirmed that convective heat transfer induced by gas diffusion increased the velocity of thermal runaway propagation by 5.46%-17.06%.Finally,the temperature rate curve was analyzed,and a three-stage mechanism for internal thermal runaway propagation was *** Stage I,convective heat transfer from electrolyte evaporation locally increased the temperature to 100℃.In Stage II,solid heat transfer locally increases the temperature to trigger thermal *** StageⅢ,thermal runaway sharply increases the local *** proposed mechanism sheds light on the internal thermal runaway propagation of blade batteries and offers valuable insights into safety considerations for future design.

关键词： Lithium-ion battery Blade battery Thermal runaway Internal thermal runaway propagation

Experimental and first-principles calculation of TiN growth mechanism on CeAlO_(3) surface in steel

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Journal of Iron and Steel Research(International) 2024年第2期31卷 452-463页

作者： Fei-hu He Jun Peng Fang Zhang yong-bin Wang hong-tao Chang School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina

Regular TiN is harmful to the toughness of steel,and its shape and size need to be *** the behavior of TiN precipitation on CeAlO_(3) surfaces is critical for controlling the morphology and formation process of CeAlO_(3)–TiN composite inclusions in the *** results showed that TiN had a square morphology on the CeAlO3 surface,and electron backscatter diffraction phase identification results revealed the orientation relationship between CeAlO_(3) and TiN as follows:(001)_(CeAlO_(3))//(110)_(TiN),(100)_(CeAlO_(3))/(001)_(TiN),and[010]_(CeAlO_(3))/[110]_(TiN).The CeAlO3 crystal structure was studied using the first-principles calculation method,and the adsorption and growth process of TiN on the CeAlO_(3) surface were investigated from the atomic *** calculation results indicate that there is no metallic bonding present in the CeAlO_(3) *** the low-index crystal planes of CeAlO_(3),the(110)planes terminated with O and CeAlO have the highest and lowest surface energies,respectively,with values of 0.373 and 0.051 eV/Å^(2).On the high surface energy plane of CeAlO_(3),the TiN atomic permutation structure is consistent with the arrangement of Ti and N atoms in TiN(100)or(110).For the low surface energy plane of CeAlO_(3),the Ti and N atoms are arranged in a ring-like structure.

关键词： CeAlO_(3)-TiN inclusion Orientation relationship Crystal structure First principle Surface energy

Predicting microbial extracellular electron transfer activity in paddy soils with soil physicochemical properties using machine learning

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Science China(Technological Sciences) 2024年第1期67卷 259-270页

作者： OU JiaJun LUO XiaoShan LIU JunYang huang LinYan ZHOU LiHua YUAN yong School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangzhou Key Laboratory Environmental Catalysis and Pollution ControlSchool of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China

Soil extracellular electron transfer(EET)is a pivotal biological process within the realm of ***,EET suffers from a lack of predictive ***,an intricately crafted machine learning model has been developed for the purpose of predicting soil EET by using the physicochemical properties of soil as independent input variables and the EET capabilities in terms of current density(j_(max))and Coulombic charge(C_(out))as dependent output *** autoencoder ensemble stacking(AES)model was developed to address the aforementioned issue by integrating support vector machine,multilayer perceptron,extreme gradient boosting,and light gradient boosting machine algorithms as the stacking *** 10-fold crossvalidation,the AES model exhibited notable improvements in predicting j_(max)and C_(out),with average test R^(2)values of 0.83 and 0.84,respectively,surpassing those of single machine learning(ML)models and the basic ensemble *** utilizing partial correlation plots(PDPs),Shapley Additive explanations(SHAP)values,and SHAP decision plots,we quantitatively explained the impact and contribution of the input molecules on the AES model’s predictions of j_(max)and C_(out).In the context of the SHAP method for the AES model,total carbon(TC)was identified as the most correlated descriptor for j_(max),while total organic carbon(TOC)stood out as the most relevant descriptor for C_(out).In the prediction tasks of j_(max)and C_(out)within the AES model,employing a multitask ML approach allowed the model to benefit from the shared information of input variables,thereby enhancing its overall *** study provides a feasible tool for the prediction of soil EET from soil physiochemical properties and an advanced understanding of the relationship between soil physiochemical properties and EET capability.

关键词： extracellular electron transfer paddy soil machine learning prediction autoencoder ensemble stacking model

Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

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Advances in Atmospheric Sciences 2024年第6期41卷 1251-1263页

作者： hong huang Dan WU Yuan WANG Zhen WANG Yu LIU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China No.31631 Army of PLA Huizhou 516000China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing 210023China No.93721 Army of PLA Shuozhou 038300China

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track *** characteristics of the six hard-clustered ETCs with the highest membership coefficient are *** tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these *** landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one *** frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four *** surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying *** results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

关键词： Western North Pacific tropical cyclone extratropical transition fuzzy c-means clustering method