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Synthesis and characterization of iron clusters with an icosahedral [Fe@Fe12]16+ Core

National Science Review 2024年第4期11卷 123-129页

作者： Gan xu Yun-Shu Cui xue-Lian Jiang Cong-qiao xu Jun Li xu-dong Chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials Science Nanjing Normal University Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and Technology Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua University State Key Laboratory of Coordination Chemistry Nanjing University

Iron-metal clusters are crucial in a variety of critical biological and material systems,including metalloenzymes,catalysts,and magnetic storage devices.However,a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron bonding.In this work,we have synthesized,crystallized,and characterized a（Tp*）4W4S12(Fe@Fe12) cluster(Tp*=tris（3,5-dimethyl-1-pyrazolyl）borate（1-）),which features a rare trideca-nuclear,icosahedral[Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron（Fei） and peripheral irons（Fep）,as well as Fep…Fepferromagnetic coupling.Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+core,assisted by its bonding interactions with the peripheral tridentate [（Tp*）WS3]4-ligands which possess both S→Fe donation and spin-polarized Fe-Wσ bonds.The ground-state electron spin is theoretically predicted to be S=32/2 for the cluster.The existence of low oxidation-state（OS～+1.23） iron in this compound may find interesting applications in magnetic storage,spintronics,redox chemistry,and cluster catalysis.

关键词： Fe13 cluster iron-sulfur cluster low-valence iron iron−iron bond high spin complex

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GPa-level pressure-induced enhanced corrosion resistance in TiZrTaNbSn biomedical high-entropy alloy

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China Foundry 2024年第3期21卷 265-275页

作者： Xiao-hong Wang Yu-lei Deng qiao-yu Li Zhi-xin xu Teng-fei Ma Xing Yang Duo dong dong-dong Zhu Xiao-hong Yang Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou 324000ZhejiangChina School of Materials Science and Engineering Taizhou UniversityTaizhou 318000ZhejiangChina

TiZrTaNb-based high-entropy alloys(HEAs)are research frontier of biomedical materials due to their high hardness,good yield strength,excellent wear resistance and corrosion resistance.Sn,as an essential trace element in the human body that plays a significant role in physiological process.It has stable chemical properties and a low elastic modulus.In this study,a new material,TiZrTaNbSn HEAs,was proposed as a potential biomedical alloy.The Ti_(35)Zr_(25)Ta_(15)Nb_(15)Sn_(10)biomedical high-entropy alloys(BHEAs)were successfully prepared through an arc melting furnace and then remelted using a German high-temperature and high-pressure apparatus under GPa-level(4 GPa and 7 GPa).The precipitation behavior of the needle-like HCP-Zr_(5)Sn_(3)phase that precipitates discontinuously at the grain boundary was successfully controlled.The phase constitution,microstructure,and corrosion resistance of the alloy were studied.The results show that the needle-like HCP-Zr_(5)Sn_(3)phase is eliminated and the(Zr,Sn)-rich nano-precipitated phase is precipitated in the microstructure under high pressure,which leads to the narrowing of grain boundaries and consequently improves the corrosion resistance of the alloy.In addition,the formation mechanisms of(Zr,Sn)-rich nanoprecipitates in BHEAs were discussed.More Zr and Sn dissolve in the matrix due to the effect of high pressure,during the cooling process,they precipitate to form a(Zr,Sn)-rich nano-precipitated phase.

关键词： biomedical HEAs precipitation grain boundary corrosion resistance TiZrTaNbSn

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Heteroatom doping regulates the catalytic performance of singleatom catalyst supported on graphene for ORR

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Nano Research 2024年第3期17卷 1086-1093页

作者： Ji-Kai Sun Yu-Wei Pan Meng-Qian xu Lei Sun Shaolong Zhang Wei-qiao Deng dong Zhai Institute of Molecular Sciences and Engineering Institute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237China College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Replacing fossil fuels with fuel cells is a feasible way to reduce global energy shortages and environmental pollution.However,the oxygen reduction reaction(ORR)at the cathode has sluggish kinetics,which limits the development of fuel cells.It is significant to develop catalysts with high catalytic activity of ORR.The single-atom catalysts(SACs)of Pt supported on heteroatom-doped graphene are potential candidates for ORR.Here we studied the SACs of Pt with different heteroatoms doping and screened out Pt-C_(4) and Pt-C_(3)O_(1) structures with only 0.13 V overpotential for ORR.Meanwhile,it is found that B atoms doping could weaken the adsorption capacity of Pt,while N or O atoms doping could enhance it.This regularity was verified on Fe SACs.Through the electronic interaction analysis between Pt and adsorbate,we explained the mechanism of this regularity and further proposed a new descriptor named corrected d-band center(ε_(d-corr))to describe it.This descriptor is an appropriate reflection of the number of free electrons of the SACs,which could evaluate its adsorption capacity.Our work provides a purposeful regulatory strategy for the design of ORR catalysts.

关键词： single-atom catalyst(SAC) oxygen reduction reaction(ORR) heteroatom doping corrected d-band center descriptor

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Towards robustness and generalization of point cloud representation:A geometry coding method and a large-scale object-level dataset

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Computational Visual Media 2024年第1期10卷 27-43页

作者： Mingye xu Zhipeng Zhou Yali Wang Yu qiao Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518000China University of Chinese Academy of Sciences Beijing065001China Shanghai AI Laboratory Shanghai200001China SIAT Branch Shenzhen Institute of Artificial Intelligence and Robotics for SocietyShenzhen518000China Alibaba DAMO Academy Hangzhou242332China

Robustness and generalization are two challenging problems for learning point cloud representation.To tackle these problems,we first design a novel geometry coding model,which can effectively use an invariant eigengraph to group points with similar geometric information,even when such points are far from each other.We also introduce a large-scale point cloud dataset,PCNet184.It consists of 184 categories and 51,915 synthetic objects,which brings new challenges for point cloud classification,and provides a new benchmark to assess point cloud cross-domain generalization.Finally,we perform extensive experiments on point cloud classification,using ModelNet40,ScanObjectNN,and our PCNet184,and segmentation,using ShapeNetPart and S3DIS.Our method achieves comparable performance to state-of-the-art methods on these datasets,for both supervised and unsupervised learning.Code and our dataset are available at https://***/Mingyexu/PCNet184.

关键词： geometry coding self-supervised learning point cloud classification segmentation 3D analysis

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Identifying the geographical origin and processing technology of Moyao(Myrrh) on the basis of near-infrared spectroscopy combined with chemometrics

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Journal of Traditional Chinese Medicine 2024年第3期44卷 505-514页

作者： xu Ningning YAN Ganming xu Fengjie DENG Linfeng qiao Xinjiang LU Changzheng CHENG Shaomin TCM Diagnosis Institute College of Traditional Chinese MedicineJiangxi University of Chinese Medicine TCM Processing Institute Pharmaceutical CollegeJiangxi University of Chinese medicine School of Electronic Information and Artificial Intelligence Shaanxi University of Science and Technology Jiangzhong Pharmaceutical Co. Ltd. Jiangxi Guhan Refined Chinese Herbal Pieces Co. Ltd.

OBJECTIVE: To evaluate the quality of Moyao(Myrrh) in the identification of the geographical origin and processing of the products. METHODS: Raw Moyao(Myrrh) and two kinds of Moyao(Myrrh) processed with vinegar from three countries were identified using near-infrared(NIR) spectroscopy combined with chemometric techniques. Principal component analysis(PCA) was used to reduce the dimensionality of the data and visualize the clustering of samples from different categories. A classical chemometric algorithm(PLS-DA) and two machine learning algorithms [K-nearest neighbor(KNN) and support vector machine] were used to conduct a classification analysis of the near-infrared spectra of the Moyao(Myrrh) samples, and their discriminative performance was evaluated. RESULTS: Based on the accuracy, precision, recall rate, and F1 value in each model, the results showed that the classical chemometric algorithm and the machine learning algorithm obtained positive results. In all of the chemometric analyses, the NIR spectrum of Moyao(Myrrh) preprocessed by standard normal variation or Multivariate scattering correction combined with KNN achieved the highest accuracy in identifying the geographical origins, and the accuracy of identifying the processing technology established by the KNN method after first-order derivative pretreatment was the best. The best accuracy of geographical origin discrimination and processing technology discrimination were 0.9853 and 0.9706 respectively. CONCLUSIONS: NIR spectroscopy combined with chemometric technology can be an important tool for tracking the origin and processing technology of Moyao(Myrrh) and can also provide a reference for evaluations of its quality and the clinical use.

关键词： Moyao () geographical origin near-infrared spectroscopy processing technology

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Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

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China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao qiao Jian Li Xiao-yang Luo Peng Peng Xian-tao Yan xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich phase.In addition,the primary Al dendrites show significant refinement with an increase in the withdrawal speed.The relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 HV.This is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

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A General Simulation Method for Complex Deformation of Irregular-Shaped Origami Configurations

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Acta Mechanica Solida Sinica 2024年第1期37卷 90-98页

作者： Zhaochen dong Yichao Zhu xu Guo State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian 116023China

Most existing treatments for origami-folding simulations have focused on regular-shaped configurations.This article aims to introduce a general strategy for simulating and analyzing the deformation process of irregular shapes by means of computational capabilities nowadays.To better simulate origami deformation with folding orders,the concept of plane follow-up is introduced to achieve automated computer simulation of complex folding patterns,thereby avoiding intersection and penetration between planes.Based on the evaluation criteria such as the lowest storage energy with tightening and the fastest pace from tightening to unfolding,the optimal crease distribution patterns for four irregular(‘N’-,‘T’-,‘O’-,and‘P’-shaped)origami configurations are then presented under five candidates.When the dimensions of the origami are fixed,it is discovered that simpler folding patterns lead to faster deformation of the origami configuration.When the folding complexity is fixed,higher strain energy results in more rapid origami expansion.

关键词： Irregular-shaped origami Complex deformation Computer-aided origami design General simulation

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Twisted Integration of Complex Oxide Magnetoelectric Heterostructures via Water‑Etching and Transfer Process

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Nano-Micro Letters 2024年第1期16卷 360-369页

作者： Guannan Yang Guohua dong Butong Zhang xu xu Yanan Zhao Zhongqiang Hu Ming Liu State Key Laboratory for Manufacturing Systems Engineering Electronic Materials Research LaboratoryKey Laboratory of the Ministry of EducationEngineering Research Center of Spin Quantum Sensor ChipsUniversities of Shaanxi ProvinceSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain engineering.In recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal orientations.Moreover,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical phenomena.In this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with 45.and 0.twist angles were assembled via water-etching and transfer process.The transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°Sample.The fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial anisotropy.This work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.

关键词： Magnetoelectric heterostructures Twist angle Epitaxial lift-off Magnetic anisotropy Ferromagnetic resonance

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Screening and identification of functional bacterial attachment genes in aerobic granular sludge

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Journal of Environmental Sciences 2024年第7期141卷 205-214页

作者： Kai qiao Tingting Zhao LeiWang Wei Zhang WeiMeng Fan Liu xu Gao Jianrong Zhu School of Environment Beijing Normal UniversityBeijing 100875China State Key Laboratory of Water Simulation Beijing 100875China R&D Centre of Aerobic Granule Technology Beijing 100875China

The screening and identification of attachment genes is important to exploring the formation mechanism of biofilms at the gene level.It is helpful to the development of key culture technologies for aerobic granular sludge(AGS).In this study,genome-wide sequencing and gene editing were employed for the first time to investigate the effects and functions of attachment genes in AGS.With the help of whole-genome analysis,ten attachment genes were screened from thirteen genes,and the efficiency of gene screening was greatly improved.Then,two attachment genes were selected as examples to further confirm the gene functions by constructing gene-knockout recombinant mutants of Stenotrophomonas maltophilia;when the two attachment genes were knocked out,the attachment potential was reduced by 50.67%and 43.93%,respectively.The results provide a new theoretical principle and efficient method for the development of AGS from the perspective of attachment genes.

关键词： Attachment gene Genome-wide sequence Gene-knockout Attachment potential Aerobic granular sludge biofilm

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The Application of Artificial Intelligence in Alzheimer’s Research

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Tsinghua Science and Technology 2024年第1期29卷 13-33页

作者： Qing Zhao Hanrui xu Jianqiang Li Faheem Akhtar Rajput Liyan qiao Faculty of Information Technology Beijing University of TechnologyBeijing 100124China School of Medicine Tsinghua UniversityBeijing 100084China Department of Computer Science Sukkur IBA UniversitySukkur 65200Pakistan Department of Neurology Tsinghua University Yuquan HospitalBeijing 100040China

Alzheimer's disease(AD)is an irreversible and neurodegenerative disease that slowly impairs memory and neurocognitive function,but the etiology of AD is still unclear.With the explosive growth of electronic health data,the application of artificial inteligence(Al)in the healthcare setting provides excellent potential for exploring etiology and personalized treatment approaches,and improving the disease's diagnostic and prognostic outcome.This paper first briefly introduces Al technologies and applications in medicine,and then presents a comprehensive review of Al in AD.In simple,it includes etiology discovery based on genetic data,computer-aided diagnosis(CAD),computer-aided prognosis(CAP)of AD using multi-modality data(genetic,neuroimaging and linguistic data),and pharmacological or non-pharmacological approaches for treating AD.Later,some popular publicly available AD datasets are introduced,which are important for advancing Al technologies in AD analysis.Finally,core research challenges and future research directions are discussed.

关键词： Alzheimer's disease artificial intelligence etiology discovery computer-aided diagnosis computer-aided prognosis treatment

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