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Graph convolutional Network combined with Semantic Feature Guidance for Deep clustering

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Tsinghua Science and Technology 2022年第5期27卷 855-868页

作者： Junfen chen Jie Han Xiangjie Meng Yan Li Haifeng Li Key Laboratory of Machine Learning and computational Intelligence of Hebei Province the College of Mathematics and Information ScienceHebei UniversityBaoding 071002China School of Applied Mathematics Beijing Normal University ZhuhaiZhuhai 519087China Department of computer Teaching Hebei UniversityBaoding 071002China

The performances of semisupervised clustering for unlabeled data are often superior to those of unsupervised learning,which indicates that semantic information attached to clusters can significantly improve feature representation *** a graph convolutional network(GcN),each node contains information about itself and its neighbors that is beneficial to common and unique features among *** these findings,we propose a deep clustering method based on GcN and semantic feature guidance(GFDc) in which a deep convolutional network is used as a feature generator,and a GcN with a softmax layer performs clustering ***,the diversity and amount of input information are enhanced to generate highly useful representations for downstream ***,the topological graph is constructed to express the spatial relationship of *** a pair of datasets,feature correspondence constraints are used to regularize clustering loss,and clustering outputs are iteratively *** external evaluation indicators,i.e.,clustering accuracy,normalized mutual information,and the adjusted Rand index,and an internal indicator,i.e., the Davidson-Bouldin index(DBI),are employed to evaluate clustering *** results on eight public datasets show that the GFDc algorithm is significantly better than the majority of competitive clustering methods,i.e.,its clustering accuracy is20% higher than the best clustering method on the United States Postal Service *** GFDc algorithm also has the highest accuracy on the smaller Amazon and caltech ***,DBI indicates the dispersion of cluster distribution and compactness within the cluster.

关键词： self-supervised clustering graph convolutional network feature correspondence semantic feature guidance confusion matrix evaluation indicator

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废旧锂电池电极材料浮选行为及表面性质

工程科学学报 2024年第1期46卷 97-108页

作者：赵光金谷昆泓夏大伟胡玉霞陈玲玲覃文庆韩俊伟国家电网国网河南省电力公司电力科学研究院郑州450052 中南大学资源加工与生物工程学院长沙410083

锂离子电池中含有丰富的金属元素和多种毒害性物质,废旧锂电池回收不仅能实现资源循环利用,而且能防止环境污染.本文以废旧动力锰酸锂电池为研究对象,利用“焙烧强化浮选”的方法解决锰酸锂电池资源化回收过程中正负极电极材料难以浮选... 详细信息

锂离子电池中含有丰富的金属元素和多种毒害性物质,废旧锂电池回收不仅能实现资源循环利用,而且能防止环境污染.本文以废旧动力锰酸锂电池为研究对象,利用“焙烧强化浮选”的方法解决锰酸锂电池资源化回收过程中正负极电极材料难以浮选分离的问题,即通过焙烧去除电极材料表面的有机粘附物,从而增大电极材料表面润湿性差异,进而强化浮选分离过程.结果表明,商品化锰酸锂和商品化石墨具有相反的浮选行为,而废旧锰酸锂和废旧石墨具有相似的疏水性浮选行为.废旧锰酸锂电极材料浮选分离时,锰酸锂和石墨浮选分离效率低,而商品化锰酸锂和石墨的浮选分离效率高.XRD、XPS、SEM、FT-IR及接触角分析表明,废旧锂电池电极材料表面均包裹一层含c、O、F等元素的有机物,导致正负极电极材料具有相似的表面性质,因而表现出相似的浮选行为,导致两者的浮选分离难度大.不同焙烧参数下电极材料的浮选分离试验结果表明,550℃焙烧2 h后锰酸锂和石墨的浮选分离效率明显优于未焙烧的电极材料.此时,浮选精矿中锰酸锂的品位由未焙烧的63.10%提高到90.98%;小型闭路浮选精矿中石墨残留量少,锰酸锂的纯度达到99%.

关键词：废旧锂电池锰酸锂正极材料负极材料浮选

Role ofδ-ferrite in fatigue crack growth of AISI 316 austenitic stainless steel

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Journal of Materials Science & Technology 2022年第19期114卷 7-15页

作者： Qiyu Wang Shenghu chen Xinliang Lv Haichang Jiang Lijian Rong cAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

FF sample(nearly free ofδ-ferrite)and cF sample(containing∼4%δ-ferrite)were prepared from the AISI 316 austenitic stainless steel plate to elucidate the role ofδ-ferrite in the fatigue crack growth under the solution treated and accelerated aged *** is found that the fatigue crack growth resistance of the cF sample is higher than the FF sample under the solution treated ***,a significant deterioration of the fatigue crack growth resistance is observed in the cF sample while little variation is found in the FF sample after accelerated aging treatment at 750°c for 10 *** the solution treated condition,deflected crack growth path is present when the main crack encounters theδ-ferrite in the cF sample due to the differences in the fatigue responses between austenite andδ-*** measured growth rate of the deflected crack is significantly slower than that of the flat crack of the same *** the accelerated aging treatment,microcracks are produced at the M_(23)c_(6)/δinterface due to the strain incompatibility between M_(23)c_(6) and retainedδ-ferrite when the decomposedδ-ferrite is subject to plastic deformation in the crack tip plastic *** preexisting microcracks in the front of crack tip provide a viable path for crack propagation,resulting in the relatively flat crack path.

关键词： Austenitic stainless steel δ-ferrite Accelerated aging Fatigue crack growth crack deflection

Elastic scattering and total reaction cross sections of^(6)Li examined via a microscopic continuum discretized coupled-channels model

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chinese Physics c 2024年第1期48卷 71-81页

作者：陈文棣庞丹阳郭海瑞叶涛孙伟力应阳君 School of Physics Beihang UniversityBeijing 100191China Institute of Applied Physics and computational Mathematics Beijing 100094China

We present a systematic study of 6Li elastic scattering and total reaction cross sections at incident energies around the coulomb barrier within the continuum discretized coupled-channels(cDcc)framework,where 6Li is treated in anα+d two-body *** with 27Al,64Zn,138Ba,and 208Pa are *** microscopic optical potentials(MOP)based on Skyrme nucleon-nucleon interaction forαand d are adopted in cDcc calculations and satisfactory agreement with the experimental data is obtained without any adjustment on *** comparison,αand d global phenomenological optical potentials(GOP)are also used in cDcc analysis and a reduction of no less than 50%on the surface imaginary part of deuteron GOP is required for describing the *** all cases,the 6Li breakup effect is significant and provides repulsive correction to the folding model *** reduction on the surface imaginary part of GOP of deuteron reveals a strong suppression of the reaction probability of deuteron as a component of 6Li when compared with that of a free *** investigation is performed by considering the d breakup process equivalently within the dynamic polarization potential approach,and the results show that d behaves in a manner similar to a tightly bound nucleus in 6Li induced reactions.

关键词： continuum discretized coupled channels method microscopic optical potential 6Li induced reaction elastic scattering total reaction cross section

镁掺杂高镍三元正极材料LiNi_(0.9)0co_(0.05)Mn_(0.05)O_(2)的合成与性能

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应用化学 2024年第4期41卷 568-576页

作者：陈胜胡祖飞曹洪美赵振华张宇栋江苏科技大学材料科学与工程学院镇江212100 湖南久日新材料有限公司怀化418200 江苏科技大学能源与动力学院镇江212100

采用高温固相法合成了一系列不同含量Mg掺杂的LiNi_(0.9)0co_(0.05)Mn_(0.05)O_(2)正极材料,并通过X射线衍射、扫描电子显微镜、透射电子显微镜和X射线光电子能谱等表征手段对其物相结构、颗粒形貌及电化学性能进行了研究。结果表明,掺... 详细信息

采用高温固相法合成了一系列不同含量Mg掺杂的LiNi_(0.9)0co_(0.05)Mn_(0.05)O_(2)正极材料,并通过X射线衍射、扫描电子显微镜、透射电子显微镜和X射线光电子能谱等表征手段对其物相结构、颗粒形貌及电化学性能进行了研究。结果表明,掺杂Mg元素虽然会降低材料的可逆容量,但是可扩大材料晶胞体积,抑制不可逆相变,改善电极与电解液的界面稳定性,可有效提升材料的循环稳定性。其中,3%摩尔分数掺杂量的LiNi_(0.9)0co_(0.05)Mn_(0.05)O_(2)正极材料结构稳定,容量损失较少,综合性能表现较好,在0.1 c、2.8~4.3 V电压范围内,首周充放电比容量达到了197.3 mA∙h/g,100周的循环保持率达到了93.6%,且5 c下放电比容量为161.1 mA∙h/g。

关键词：锂离子电池正极材料元素掺杂电化学性能

classification and quantification of excavated soil and construction sludge:A case study in Wenzhou,china

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Frontiers of Structural and civil Engineering 2022年第2期16卷 202-213页

作者： Qimeng GUO Liangtong ZHAN Yunyang SHEN Linbo WU Yunmin chen MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou310058China college of civil Engineering and Architecture Zhejiang Sci-Tech UniversityHangzhou310018China

With rapid urbanization in china,a large amount of excavated soil and construction sludge is being generated from geotechnical and underground *** sustainable management of these construction wastes,it is essential to quantify their production *** present study has attempted to classify the excavated soil and construction sludge according to their composition and geotechnical properties(particle size,water content,plasticity index).Based on these classifications,a new approach was proposed to quantify the *** said approach was based on multi-source information,such as the urban topographic map,geological survey reports,urban master plan,and remote sensing images.A case study in Wenzhou city of china was also pursued to illustrate the validity of the newly developed *** research showed that in 2021–2025,the total excavated soils and construction sludge production in Wenzhou would reach 107.5×10^(6) and 81.7×10^(6) m^(3),***,the excavated soil was classified into the miscellaneous fill,crust clay,muddy clay and mud with silty ***,the construction sludge was classified as liquid sludge and paste-like *** classification and quantification can serve as guidance for disposal and recycling,thereby leading to high-level management of waste disposal.

关键词： excavated soil construction sludge geotechnical and underground engineering production classification

Mitigating the Jahn-Teller distortion driven by the spin-orbit coupling of lithium manganate cathode

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Journal of Energy chemistry 2022年第9期31卷 379-387,I0011页

作者： Shu Zhang Hongyi chen Jun chen Shouyi Yin Yu Mei Lianshan Ni Andi Di Wentao Deng Guoqiang Zou Hongshuai Hou Xiaobo Ji State Key Laboratory of Powder Metallurgy College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083HunanChina Department of Materials and Environmental chemistry Stockholm UniversityStockholm 10691Sweden

Spinel LiMn_(2)O_(4)is recognized as one of the most competitive cathode candidates for lithium-ion batteries ascribed to environmentally benign and rich ***,the wholesale application of LiMn_(2)O_(4)is predominately plagued by its severe capacity degradation,mainly associated with the innate Jahn-Teller ***,single-crystalline LiMn_(2)O_(4)with Eu^(3+) doping is rationally designed to mitigate the detrimental Jahn-Teller distortion by tuning the chemical environment of MnO_(6) octahedra and accommodating localized electron,based on the unique aspheric flexible 4f electron orbit of rare-earth metal ***,the stretching of MnO_(6) octahedron stemmed from the Jahn-Teller effect in Eu-doped LiMn_(2)O_(4)is effectively suppressed,confirmed by theoretical ***,the structural stability of the material has been significantly enhanced due to the robust Mn–O band coherency and weakened phase transition,proved by synchrotron radiation absorption spectrum and operando X-ray *** corresponding active cathode manifests superior long-cycle stability after 300 loops at 2c and displays only a 0.011%capacity drop per cycle even at *** this,this modification tactic sheds new light on achieving superior long-cycle performances by suppressing distortion in various cathode materials.

关键词： Spinel lithium manganate Spin-orbit coupling Jahn-Teller distortion cathode material

N-gram MalGAN:Evading machine learning detection via feature n-gram

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Digital communications and Networks 2022年第4期8卷 485-491页

作者： Enmin Zhu Jianjie Zhang Jijie Yan Kongyang chen chongzhi Gao School of computer Science and cyber Engineering Guangzhou UniversityGuangzhou510006China Institute of Artificial Intelligence and Blockchain Guangzhou UniversityGuangzhou510006China Pazhou Lab Guangzhou510330China

In recent years,many adversarial malware examples with different feature strategies,especially GAN and its variants,have been introduced to handle the security threats,e.g.,evading the detection of machine learning ***,these solutions still suffer from problems of complicated deployment or long running *** this paper,we propose an n-gram MalGAN method to solve these *** borrow the idea of n-gram from the Natural Language Processing(NLP)area to expand feature sources for adversarial malware examples in ***,the n-gram MalGAN obtains the feature vector directly from the hexadecimal bytecodes of the executable *** can be implemented easily and conveniently with a simple program language(e.g.,c++),with no need for any prior knowledge of the executable file or any professional feature extraction *** features are functionally independent and thus can be added to the non-functional area of the malicious program to maintain its original *** this way,the n-gram could make the adversarial attack easier and more *** results show that the evasion rate of the n-gram MalGAN is at least 88.58%to attack different machine learning algorithms under an appropriate group rate,growing to even 100%for the Random Forest algorithm.

关键词： Machine learning N-gram MalGAN Adversarial examples

core-shell Ni_(3)Sn_(2)@c particles anchore d on 3D N-dope d porous carbon skeleton for modulated electromagnetic wave absorption

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Journal of Materials Science & Technology 2023年第27期158卷 242-252页

作者： Hongxia Zhang Kaige Sun Kangkang Sun Lei chen Guanglei Wu Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao University266071 QingdaoChina State Key Laboratory of Tribology Tsinghua University100084 BeijingChina School of chemical Engineering The University of Queensland4072 St LuciaQLDAustralia

Synthesizing multi-component composites via a straightforward,reliable,and scalable approach has been ***,a three-dimensional nitrogen-doped porous carbon decorated with core-shell Ni_(3)Sn_(2)@carbon particles(3D N-Pc/Ni_(3)Sn_(2)@c)was customized through a simple salt-template pyrolysis *** formed Ni_(3)Sn_(2) particles are perfectly surrounded by crystalline carbon layers and em-bedded in 3D carbon walls during *** dual protection of crystalline carbon layers and porous carbon walls guarantees the electrical conductivity and stability of Ni_(3)Sn_(2).The intriguing 3D and core-shell structure coupled with the introduction of multiple components empowers the composite with rich heterogeneous interface and conductive network,and contributes to the lightweight,corrosion resistance,oxidation resistance,and superior stability of electromagnetic(EM)wave *** N-Pc/Ni_(3)Sn_(2)@c possesses the minimum reflection loss(RL min)of-54.01 dB and wide effective absorption bandwidth(EAB)of 7.36 GHz under a low filler content of less than 10%.The concept in the work proposes a facile,eco-friendly,and scalable pathway for the synthesis of other heterogeneous structures of EM wave ab-sorbers.

关键词： Nitrogen doping Ni_(3)Sn_(2) 3D conductivity network Microwave absorption Ultra-low filler loading