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Nano Research 2022年第8期15卷 7016-7025页

作者： Qing Liu Xiaoxu Wang Lu Li Keke Song ping Qian Yuan Ping Feng Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Department of Physics Faculty of ScienceNational University of SingaporeSingapore 117551Singapore DP Technology Beijing 100080China

Inspired by the single-atom catalysts(SACs)concept,we rationally design a series of Pt single atom catalysts embedded in different transition metal nanoclusters through first-principles calculations.In these so-called“crown-jewel”(CJ)structures,Pt atoms(jewels)occupy the vertex sites of the metal nanocluster(crown)surface.We investigated the thermal stability and oxygen reduction reaction(ORR)catalytic activity of these catalysts.The results reveal that CJ-structured PtCu nanoclusters are stable and possess a comparable or even better ORR activity compared to Pt catalyst,making it a promising candidate for low-cost ORR catalysts.The effect of cluster size on the adsorption strength of ORR intermediates and catalytic property has also been studied.Furthermore,the overall ORR catalytic activity trend of these SACs is explained based on analysis of their electronic properties.A descriptorΨwas established to provide further insight into the correlation between the electronic structure and catalytic activity,which provides a design strategy for new ORR catalysts.More importantly,we reveal that this electronic descriptor can be extended to predict other CJ-structured nanoclusters.

关键词： single-atom catalysts crown-jewel oxygen reduction reaction(ORR) catalyst design nanocluster

A versatile model with three-dimensional triangular lattice for unconventional transport and various topological effects

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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

High-Throughput Computational Discovery and Intelligent Design of Two-Dimensional Functional Materials for Various Applications

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Accounts of Materials Research 2022年第6期3卷 572-583页

作者： Lei Shen Jun Zhou Tong Yang Ming Yang Yuan Ping Feng Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A*STAR)138634Singapore Department of Physics National University of SingaporeSingapore 117551Singapore Department of Applied Physics The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SARChina

Novel technologies and new materials are in high demand for future various applications to overcome the fundamental limitations of current techniques.For example,the nanomaterials are in high demand for the miniaturization of electric devices.Spintronics is one of the most viable solutions for green electric devices.The single-atom catalysts can provide a 100%utilization rate.Heterojunctions hold promise for applications in energy conversion and storage.Two-dimensional(2D)materials show promising applications in various applications because they can be tailored to the specific property on which a technology is based and may be compatible with other technologies.Although the number of experimentally discovered 2D materials is growing,the speed is very slow and only a few dozen 2D materials have been synthesized or exfoliated since the discovery of graphene.Recently,a novel computational technique,dubbed high-throughput computational materials design,has become a burgeoning area of materials science,which is a combination of quantum mechanical theory,materials information,and database construction with intelligent data mining.This new and powerful tool can greatly accelerate the discovery,design,and application of 2D materials by creating a database containing a large number of 2D materials with calculated fundamental properties and then intelligently mining(via high-throughput automation or machine learning)the database in the search for 2D materials with the desired properties for particular applications,such as energy conversion/storage,catalysis,water purification,electronics,and optoelectronics.In this Account,we summarize our recent progress in the emerging area of 2D materials discovery,database construction,2D functional materials design,and device development by quantum-mechanical modeling,high-throughput calculations,and machine learning inspired by the materials genome concept.We developed an open 2D materials database−2D materials encyclopedia(2DMatPedia;http://www.***.org/),which includes a vari

关键词： ferroelectric Outlook overcome

General Model of Temperature-dependent Modulus and Yield Strength of Thermoplastic Polymers

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Chinese Journal of Polymer Science 2020年第4期38卷 382-393,I0007页

作者： ping-yuan Huang Zhan-Sheng Guo Jie-Min feng Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

A general model was developed to predict the temperature-dependent modulus and yield strength of different thermoplastic polymers.This model,which depends on only two parameters with clear and specific physical meanings,can describe the temperaturedependent modulus and yield strength of thermoplastic polymers over the full glass transition region.The temperature-dependent modulus and yield strength of three thermoplastic polymers were measured by uniaxial tension tests over a temperature range of 243-383 K.The predictions showed excellent agreement with the experimental data.Sensitivity analysis of model input parameters showed negligible effect on the present general model.The universality of the present general model was further validated,showing excellent agreement with published experimental data on other thermoplastic polymers and their composites.

关键词： Thermoplastics Modulus Yield strength Modeling Glass transition

Hierarchical self-assembly of crown ether based metal-carbene cages into multiple stimuli-responsive cross-linked supramolecular metallogel

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Science China Chemistry 2021年第7期64卷 1177-1183页

作者： Zi-En Zhang yuan-yuan An Bo Zheng Jin-ping Chang Ying-feng Han College of Chemistry and Materials Science Northwest UniversityXi'an 710127China School of Pharmaceutical Sciences Nanjing Tech UniversityNanjing 211816China

The hierarchical self-assembly(HSA) strategy widely utilized in biological systems has been applied in artificial systems to orchestrate small building blocks into complex functional architectures. The non-interfering interactions glue various building blocks together and produce new species with attractive properties. Herein, we functionalized NHC-based assemblies with orthogonal host–guest interaction to fabricate metal-carbene based supramolecular polymer gel. A series of unique crown etherappended cylinder-like trinuclear AuIhexacarbene assemblies [Au_(3)(L)_(2)](PF_(6))_(3)(L=D1–D4, A1–A4) were synthesized from the corresponding trisimidazolium salts H_(3)-L(PF_(6))_(3)(L=D1–D4, A1–A4) in which the N-wingtip of the imidazole moieties were substituted with three identical crown ether groups of different sizes(B15C5, B18C6, B21C7, DB24C8). The gold carbene assembly is able to complex six ammonium salts without disrupting the underlying metal-carbene cylinders. In addition, the supramolecular polymer metallogel featuring a multiple-responsiveness can be formed by using [Au_(3)(A_(4))_(2)](PF_(6))_(3) appended with DB24C8 as the core and bisammonium salt as the cross-linker. The case of introducing orthogonal interaction to NHC moiety by N-wingtip substitution demonstrates the feasibility and the power of such strategy to expand the NHC-based supramolecular system and endow them with novel properties.

关键词： N-heterocyclic carbene metallogel crown ether orthogonal interaction

Genome of striped eel catfish(Plotosus lineatus) provides insights into the adaptive evolution of amphidromous fish

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Zoological Research 2023年第2期44卷 349-352页

作者： feng Shao Ze-Chen Wu yuan Xu ping Li Zuo-Gang Peng Key Laboratory of Freshwater Fish Reproduction and Development(Ministry of Education) Southwest University School of Life SciencesChongqing 400715China College of Fisheries Southwest UniversityRongchangChongqing 402460China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXiningQinghai 810008China

DEAR EDITOR,Dramatic changes in habitat can have a range of effects on organisms(Bi & Zhang, 2021). Plotosus lineatus is a representative fish within Ostariophysi showing adaptation from freshwater habitats to the ocean. Here, we sequenced the genome of P. lineatus using long-read and Hi-C sequencing technology. Based on the high-quality chromosome-level genome, we explored the molecular basis of various P. lineatus features, including large genome with fewer chromosomes, novel dendritic organ(DO).

关键词： technology evolution habitat

Processing of high-precision ceramic balls with a spiral V-groove plate

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Frontiers of Mechanical Engineering 2017年第1期12卷 132-142页

作者： Ming feng Yongbo WU Julong yuan Zhao ping Department of Machine InteUigence & Systems Engineering AkitaPrefectural University Akita 015-0055 Japan Ultra-Precision Machining Center Zhejiang University of TechnologyHangzhou 310014 China

As the demand for high-performance bearings gradually increases, ceramic balls with excellent proper- ties, such as high accuracy, high reliability, and high chemical durability used, are extensively used for high- performance bearings. In this study, a spiral V-groove plate method is employed in processing high-precision ceramic balls. After the kinematic analysis of the ball-spin angle and enveloped lapping trajectories, an experimental rig is constructed and experiments are conducted to confirm the feasibility of this method. Kinematic analysis results indicate that the method not only allows for the control of the ball-spin angle but also uniformly distributes the enveloped lapping trajectories over the entire ball surface. Experimental results demonstrate that the novel spiral V- groove plate method performs better than the conventional concentric V-groove plate method in terms of roundness, surface roughness, diameter difference, and diameter decrease rate. Ceramic balls with a G3-1evel accuracy are achieved, and their typical roundness, minimum surface roughness, and diameter difference are 0.05, 0.0045, and 0.105 μm, respectively. These findings confirm that the proposed method can be applied to high-accuracy and high-consistency ceramic ball processing.

关键词： bearing ceramic ball spiral V-groove,kinematic analysis trajectory

Interlayer coupling effect in van der Waals heterostructures of transition metal dichalcogenides

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Frontiers of physics 2021年第1期16卷 17-22页

作者： yuan-yuan Wang feng-ping Li Wei Wei Bai-Biao Huang Ying Dai School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China

Van der Waals(vdW)heterobilayers formed by two-dimensional(2D)transition metal dichalcogenides(TMDCs)created a promising platform for various electronic and optical properties,ab initio band results indicate that the band offset of type-Ⅱband alignment in TMDCs vdW heterobilayer could be tuned by introducing Janus WSSe monolayer,instead of an external electric field.On the basis of symmetry analysis,the allowed interlayer hopping channels of TMDCs vdW heterobilayer were determined,and a four-level k·p model was developed to obtain the interlayer hopping.Results indicate that the interlayer coupling strength could be tuned by interlayer electric polarization featured by various band offsets.Moreover,the difference in the formation mechanism of interlayer valley excitons in different TMDCs vdW heterobilayers with various interlayer hopping strength was also clarified.

关键词： van der Waals heterostructures transition metal dichalcogenides interlayer coupling effects k·p model interlayer exciton

Semi-analytical Formula for Pricing Bilateral Counterparty Risk of CDS with Correlated Credit Risks

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Acta Mathematicae Applicatae Sinica 2018年第2期34卷 209-236页

作者： feng LIN Si-yuan XIE Jing-ping YANG LMEQF Department of Financial Mathematics Peking University

Based on the framework of [7], we discuss pricing bilateral counterparty risk of CDS, where each individual default intensity is modeled by a shifted CIR process with jump （3CIR＋＋）, and the correlation between the default times is modeled by a copula function. We present a semi-analytical formula for pricing bilateral counterparty risk of CDS, which is more convenient to compute through calculating multiple numerical integration or using Monte-Carlo simulation without simulating default times. Moreover, we obtain simpler formulae under FGM copulas, Bernstein copulas and CA＇B copulas, which can be applied for speeding up the computation and reducing the pricing error. Numerical results under FGM copulas and CA＇B copulas show that our method performs better both in computation speed and accuracy.

关键词： bilateral counterparty risk CDS JCIR＋＋ copula function semi-analytical formula

Regularity Criteria of Axisymmetric Weak Solutions to the 3D Magnetohydrodynamic Equations

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Acta Mathematicae Applicatae Sinica 2013年第2期29卷 289-302页

作者： Bao-quan yuan feng-ping LI School of Mathematics and Information Science Henan Polytechnic University

In this paper, we study the regularity criteria for axisymmetric weak solutions to the MHD equa- tions in R3. Let we, Jo and ue be the azimuthal component of w, J and u in the cylindrical coordinates, respectively. Then the axisymmetric weak solution （u,b） is regular on （0, T） if （wo,Jo） E Lq（O,T;Lp） or （oae,V（uoeo）） e Lq（0,T;Lp） with 3 ＋ 2 〈 2, 3 〈 p 〈 oo. In the endpoint case, one needs conditions （we, Jo） C LI（0, T;B∞∞） or （wo, V（uoeo）） C LI（0, T;B ∞∞）.

关键词： regularity criteria axisymmetric solutions Besov space