检索结果-南通市图书馆

National Science Review 2024年第1期11卷 204-214页

作者： Jing-Yang You Gang Su Yuan Ping Feng Department of Physics National University of Singapore Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Centre for advanced 2D Materials National University of Singapore

The finite Berry curvature in topological materials can induce many subtle phenomena, such as the anomalous Hall effect(AHE), spin Hall effect(SHE), anomalous Nernst effect(ANE), non-linear Hall effect(NLHE) and bulk photovoltaic effects. To explore these novel physics as well as their connection and coupling, a precise and effective model should be developed. Here, we propose such a versatile model—a 3D triangular lattice with alternating hopping parameters, which can yield various topological phases,including kagome bands, triply degenerate fermions, double Weyl semimetals and so on. We reveal that this special lattice can present unconventional transport due to its unique topological surface states and the aforementioned topological phenomena, such as AHE, ANE, NLHE and the topological photocurrent effect. In addition, we also provide a number of material candidates that have been synthesized experimentally with this lattice, and discuss two materials, including a non-magnetic triangular system for SHE, NLHE and the shift current, and a ferromagnetic triangular lattice for AHE and ANE. Our work provides an excellent platform, including both the model and materials, for the study of Berry-curvature-related physics.

关键词： three-dimensional triangular lattice different topological phases various topological effects Berry curvature

Enhanced Crystallization of Poly(butylene adipate-co-terephthalate)by a Self-assembly Nucleating Agent

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 663-674,I0010页

作者： Cheng Zhou Kun Chen Zi-Heng Zhang Meng-Fan Jing Chun-Tai Liu Chang-Yu Shen Ya-Ming Wang State Key Laboratory of Structural analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Poly(butylene adipate-co-terephthalate)(PBAT)is a promising biodegradable flexible polymer but suffers from slow crystallization rate,making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene(LDPE).This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide(OMBH).PBAT/OMBH composites with various OMBH contents(0 wt%,0.5 wt%,0.7 wt%,1 wt%,2 wt%,3 wt%and 5 wt%)were prepared through melt-mixing.The effect of OMBH on the crystallization behavior,morphologies and mechanical properties of PBAT was investigated.The highest nucleation efficiency value of 59.6%was achieved for PBAT with 0.7 wt%OMBH,much higher than that of 22.7%for PBAT with 0.7 wt%talc.Atomic force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of PBAT.Fourier transform infrared spectroscopy(FTIR)combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N—H…O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of crystallization.The presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical properties.This work is essential for preparing PBAT with high crystallization rate,enhancing its potential applications in injection-molded products.

关键词： Poly(butylene adipate-co-terephthalate) Biodegradable Self-assembly nucleating agent Crystallization

维普期刊数据库

Effect of Central Multiphase Microstructure of Thick Plates on Work Hardening and Crack Propagation

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 325-338页

作者： Lei Hu Liqin Zhang Feng Hu Kuan Zheng Guohong Zhang Collaborative Innovation center for advanced Steels Wuhan University of Science and TechnologyWuhan430081China Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081China analysis and Testing center Wuhan University of Science and TechnologyWuhan430081China

The effect of multiphase microstructure in the center segregation zones(CSZ)of high-strength steel thick plates on work hardening characteristics and crack initiation/propagation were studied.Microstructure was correlated with deformation damage behavior by using Taylor factor(TF)gradients,kernel average misorientation(KAM),and geometric necessary dislocation(GND)density.The results show that the segregation leads to a mixed structure of ferrite(soft phase)and martensite/bainite(hard phase)in the center of the thick plate.Compared to the 1/4 thickness(1/4 T)region,grain refinement occurred in the CSZ,with KAM values increasing from 0.24 to 0.49 and a decrease in the proportion of high-angle grain boundaries(>15°)from 77.4 to 51.8%.In the process of deformation,due to the influence of grain refinement and adjacent martensite/bainite,ferrite grains were divided into structural units with different TF values.The higher KAM value and GND density at the interface between soft/hard phases resulted in severe work hardening.In addition,the presence of micron-sized inclusions in the CSZ caused local strain concentration and non-continuous deformation of the matrix,which induced crack initiation.The fracture surface showed a mixed mode of brittle cleavage fracture and ductile fracture.

关键词： Thick plate center segregation zone Multiphase microstructure Taylor factor Crack propagation

Weak interaction-steered evolution of polyoxovanadate-based metal-organic polyhedra from transformation via interlock to packing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 527-533页

作者： Yan-Hu Wang Ke-Wei Tong Chao-Qin Chen Jing Du Peng Yang College of Chemistry and Chemical Engineering Advanced Catalytic Engineering Research Center of the Ministry of EducationHunan UniversityChangsha 410082China College of Chemistry and Materials Science Testing and Analysis CenterHebei Normal UniversityShijiazhuang 050024China

A bottleneck in biomimetic synthesis consists in the full copy of,for example,the hierarchical structure of proteins directed by weak interactions.By contrast with covalent bonds bearing definite orientation and high stability,weak intermolecular forces within a continuous dynamic equilibrium can be hardly tamed for molecular design.In this endeavor,a ligand-dominated strategy that embodies tunable electrostatic repulsion andπ···πstacking was first employed to shape polyoxovanadate-based metal-organic polyhedra(VMOPs).Structural evolution involving transformation,interlock,and discovery of an unprecedented prototype of the Star of David was hence achievable.Not only as a handy tool for the primary structural control over VMOPs,these weak forces allow for an advanced management on the spatial distribution of such manmade macromolecules as well as the associated physicochemical behaviors,representing an ideal model for simulating and interpreting the conformation-function relationship of proteins.

关键词： Polyoxometalates Polyoxovanadates Metal-organic polyhedron Interlock Weak intermolecular forces

维普期刊数据库

Binary Hybrid Artificial Hummingbird with Flower Pollination Algorithm for Feature Selection in Parkinson’s Disease Diagnosis

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第2期21卷 1003-1021页

作者： Liuyan Feng Yongquan Zhou Qifang Luo College of Artificial Intelligence Guangxi University for NationalitiesNanning530006China Xiangsihu College of Guangxi University for Nationalities Nanning532100GuangxiChina Guangxi Key Laboratories of Hybrid computation and IC Design analysis Nanning530006China

Parkinson’s disease is a neurodegenerative disorder that inflicts irreversible damage on humans.Some experimental data regarding Parkinson’s patients are redundant and irrelevant,posing significant challenges for disease detection.Therefore,there is a need to devise an effective method for the selective extraction of disease-specific information,ensuring both accuracy and the utilization of fewer features.In this paper,a Binary Hybrid Artificial Hummingbird and Flower Pollination Algorithm(FPA),called BFAHA,is proposed to solve the problem of Parkinson’s disease diagnosis based on speech signals.First,combining FPA with Artificial Hummingbird Algorithm(AHA)can take advantage of the strong global exploration ability possessed by FPA to improve the disadvantages of AHA,such as premature convergence and easy falling into local optimum.Second,the Hemming distance is used to determine the difference between the other individuals in the population and the optimal individual after each iteration,if the difference is too significant,the cross-mutation strategy in the genetic algorithm(GA)is used to induce the population individuals to keep approaching the optimal individual in the random search process to speed up finding the optimal solution.Finally,an S-shaped function converts the improved algorithm into a binary version to suit the characteristics of the feature selection(FS)tasks.In this paper,10 high-dimensional datasets from UCI and the ASU are used to test the performance of BFAHA and apply it to Parkinson’s disease diagnosis.Compared with other state-of-the-art algorithms,BFAHA shows excellent competitiveness in both the test datasets and the classification problem,indicating that the algorithm proposed in this study has apparent advantages in the field of feature selection.

关键词： Artificial Hummingbird Algorithm Flower pollination algorithm Feature selection Parkinson’s disease Meta-heuristic

Integration of urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays within porous copper current collector for superior performance Li-ion battery anodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 599-611页

作者： Xue-Ru Zhang Qiong Wu Yong Zhang Xi-Fei Li Ting Xie Yu-Cheng Wu Instrumental analysis center Hefei University of TechnologyHefei230009China Key Laboratory of advanced Functional Materials and Devices of Anhui Province Hefei230009China School of Materials Science and Engineering Hefei University of TechnologyHefei230009China Institute of advanced Electrochemical Energy Xi’an University of TechnologyXi’an710048China

Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox couples.However,low conductivity,poor rate capacity and rapid capacity fading have seriously impaired its practical applications.To overcome the inferiorities,urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization process.In a typical nanowire,the core is composed of interconnected MnCo_(2)O_(4)nanoparticles and the shell shows as a thin amorphous carbon layer.The integrated MnCo_(2)O_(4)@C/Cu structure could act as working anodes without using additives or polymer binders.While MnCo_(2)O_(4)@C/Cu possesses slightly longer Li-ion insertion/desertion pathway than that of MnCo_(2)O_(4)/Cu,the carbon shell could effectively prevent the pulverization of MnCo_(2)O_(4) and lower down charge transfer resistance and actively participate in Li-ion cycles.The rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase films.As a result,the MnCo_(2)O_(4)@C/Cu electrode presents superior rate capacity(600 mAh·g^(−1) at 1 A·g^(−1)) and better stability(797 mAh·g^(−1) after 200 cycles at 100 mA·g^(−1)).The excellent reversible Li ion storage capacity,cycling stability and rate capacity endow MnCo_(2)O_(4)@C/Cu great potential as stable and high output integrated anode materials in Li-ion batteries.

关键词： MnCo_(2)O_(4)@C Urchin-like nanowire arrays Core-shell Integrated anode materials Lithium-ion batteries

维普期刊数据库

A novel structure of ultra-high-loading small moleculesencapsulated ZIF-8 colloid particles

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2929-2940页

作者： Pengfei Duan Yunhe An Xiaoxiao Wei Yanjie Tian Di Guan Xiangwen Liu Lanqun Mao Institute of analysis and Testing Beijing Academy of Science and Technology(Beijing Center for Physical and Chemical Analysis)Beijing 100089China College of Chemistry Beijing Normal UniversityBeijing 100875China

The safety of nanoparticle-based drug delivery systems(DDSs)for cancer treatment is still a challenge,restricted by the intrinsic cytotoxicity of drug carriers and leakage of loaded drug.Here,we propose a novel nanocarrier’s cytotoxicity avoidance strategy by synthesizing an encapsulation core–shell structure of zeolitic imidazolate framework-8(ZIF-8)-based colloid particles(CPs)with an amorphous ZIF-8 skin.This encapsulation structure achieves an ultra-high loading rate(LR)of 90%(i.e.,9 mg doxorubicin(DOX)per 1 mg ZIF-8)for DOX and the protection of DOX from leaking.Notably,to deliver unit-dose drug,this ultra-high LR of 90%significantly reduces the usage of ZIF-8 to 1.2%(2 orders of magnitude)compared to that of DOX@ZIF-8 with a 10%LR,in which cytotoxicity of ZIF-8 could well below the safety limit and then be relatively ignored.Safety,drug delivery efficacy,scale-up ability,and universality of this encapsulation structure have been further verified.Our findings suggest the great potential of this ZIF-8-based encapsulation core–shell structure in the field of drug delivery.

关键词： metal-organic frameworks zeolitic imidazolate framework-8(ZIF-8) drug delivery nanoparticles nanostructures

Fracture mechanism of inclusions in thick plate center under tensile loading

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第5期31卷 1196-1209页

作者： Lei Hu Li-qin Zhang Feng Hu Guo-hong Zhang Kuan Zheng Collaborative Innovation center for advanced Steels Wuhan University of Science and TechnologyWuhan430081HubeiChina Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081HubeiChina analysis and Testing center Wuhan University of Science and TechnologyWuhan430081HubeiChina

Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and toughness.The formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization techniques.The results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation mechanisms.The local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the matrix.The existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack propagation.The difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.

关键词： Thick plate Inclusion Finite element simulation Critical fracture stress Fracture mechanism

Highly oriented MXene/polyvinyl alcohol films prepared by scalable layer-by-layer blade coating for efficient electromagnetic interference shielding and infrared stealth

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5651-5660页

作者： Jingyu Dong Zhaoyang Li Congqi Liu Bing Zhou Chuntai Liu uezhan Feng State Key Laboratory of Structural analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou 450002China Shangqiu Normal University Shangqiu 476000China

Controlling the orientation of two-dimensional MXene within layered films is essential to optimize or tune their mechanical properties and electromagnetic interference shielding(EMI)performance,but achieving the high orientation MXene layers on an industrial scale remains a challenging goal.In this paper,a scalable layer-by-layer blade coating(LbLBC)method was employed to fabricate highly oriented MXene/polyvinyl alcohol(PVA)films.During the LbLBC process,MXene/PVA colloid suffered a strong shearing effect,which induced the ordered alignment of MXene nanosheets along the direction of the blade movement.The orientation of MXene can be effectively adjusted by changing the scraping gap of LbLBC,achieving a maximum Herman orientation factor f of 0.81.As a result,the mechanical properties and EMI performance of the as-prepared MXene/PVA films are in direct proportion to their orientation,with the optimal values of tensile strength of 145.5 MPa,fracture strain of 19.6%,toughness of 17.7 MJ·m^(−3),and EMI shielding effectiveness of 36.7 dB.Furthermore,the inherently low mid-infrared(mid-IR)emissivity of MXene,combined with the densely oriented structure affords the composite films with IR stealth,resulting in a substantial decrease from 150 to 66.1℃in the radiative temperature of a surface.Conclusively,these scalable MXene/PVA films exhibit remarkable potential for integration into the next generation of multifunctional protective camouflage materials.

关键词： MXene nanosheets densely oriented structure layer-by-layer blade coating electromagnetic interference shielding infrared stealth

Discriminatively Constrained Semi-Supervised Multi-View Nonnegative Matrix Factorization with Graph Regularization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Big Data Mining and Analytics 2024年第1期7卷 55-74页

作者： Guosheng Cui Ye Li Jianzhong Li Jianping Fan Shenzhen Institute of advanced Technology Chinese Academy of SciencesShenzhen 518055China Joint Engineering Research center for Health Big Data Intelligent analysis Technology Shenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China School of Computer Science and Control Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Nonnegative Matrix Factorization(NMF)is one of the most popular feature learning technologies in the field of machine learning and pattern recognition.It has been widely used and studied in the multi-view clustering tasks because of its effectiveness.This study proposes a general semi-supervised multi-view nonnegative matrix factorization algorithm.This algorithm incorporates discriminative and geometric information on data to learn a better-fused representation,and adopts a feature normalizing strategy to align the different views.Two specific implementations of this algorithm are developed to validate the effectiveness of the proposed framework:Graph regularization based Discriminatively Constrained Multi-View Nonnegative Matrix Factorization(GDCMVNMF)and Extended Multi-View Constrained Nonnegative Matrix Factorization(ExMVCNMF).The intrinsic connection between these two specific implementations is discussed,and the optimization based on multiply update rules is presented.Experiments on six datasets show that the effectiveness of GDCMVNMF and ExMVCNMF outperforms several representative unsupervised and semi-supervised multi-view NMF approaches.

关键词： multi-view semi-supervised clustering discriminative information geometric information feature normalizing strategy