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Hygrothermal effect on high-velocity impact resistance of woven composites

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Defence Technology（防务技术） 2022年第5期18卷 823-833页

作者： Xiao-chen Yang nan jia School of Urban Construction Eastern Liaoning UniversityWenhua 325Dandong118003China College of Safety Science and Engineering Liaoning Technical UniversityFuxin123000China China Coal Technology&Engineering Group Shenyang Research Institute Fushun113122China State Key Laboratory of Coal Mine Safety Technology Fushun113122China

The woven glass fiber reinforced composites(GFRP)subjected to high-speed impact is investigated to identify the hygrothermal aging effect on the impact *** the hygrothermal aged and unaged glass/epoxy laminates are subjected to different impact velocities,which is confirmed as a sensitive factor for the failure modes and *** results show the hygrothermal aging effect decreases the ballistic limit by 14.9%,but the influence on ballistic performance is limited within the impact velocity closed to the ballistic *** failure modes and energy dissipation mechanisms are confirmed to be slightly influenced by the hygrothermal aging *** hygrothermal aging effect induced localization of structural deformation and degradation of mechanical properties are the main reasons for the composite undergoing the same failure modes at smaller impact *** on the energy absorption mechanisms,analytical expressions predict the ballistic limit and energy absorption to reasonable accuracy,the underestimated total energy absorption results in a relatively poor agreement between the measured and predicted energy absorption efficiency.

关键词： Hygrothermal aging effect Woven glass/epoxy composite Impact resistance Dynamic failure Energy absorption

The Influence of Wind Speed and Sea States on Whitecap Coverage

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Journal of Ocean University of China 2019年第2期18卷 282-292页

作者： jia nan ZHAO Dongliang College of Oceanic and Atmospheric Sciences Ocean University of China Physical Oceanography Laboratory Ocean University of China

Callaghan and White(2009) put forward the automated whitecap extraction(AWE) technique to determine the whitecap coverage(W). An improved AWE was used to analyze images collected in the South China Sea during 2012 and 2013 and in western Pacific during 2015 to determine W. The influences of meteorological and oceanographic factors on whitecap coverage were investigated in this study. It is found that W increases with wind speed. Scale factor and exponent of parameterization for W(U10) vary greatly in different models. Overall, there is a larger scatter of W at low wind speed than at high wind speed. W decreases with the increasing of wave age. Compared with wind speed, the scatter of W is smaller with wave age, which means the impact of wave age on the whitecap coverage is more robust under various environmental conditions. There is no significant dependence on SST and whitecap coverage seems to weakly decrease with SST. W decreases with the atmospheric stability. Relationship between W and wind speed change when swells are dominant. Swell can suppress wave breaking and decrease W. The effect is independent of the deflection angle between wind wave and swell.

关键词： whitecap coverage AWE wave age SST thermal stability swell

A numerical study of hydrodynamic influence on collision of brash ice with a structural plate

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Journal of Hydrodynamics 2022年第1期34卷 43-51页

作者： Li Zhou Zhi Zong jia-nan Li School of Naval Architecture Dalian University of TechnologyDalian116024China Tianjin Branch HuaDian Heavy Industries Co.Ltd Tianjin300010China

The ice-structure collision is a transient process, which is further complicated by the presence of the water. It remains unclear how important the hydrodynamic influences are during the collision. This problem is partially investigated in this paper using numerical methods. To simplify the problem as much as possible without loss of generality, a short ice cylinder of circular section is assumed to collide with a vertical large structure plate under a variety of collision scenarios. Among them the most important cases are: (1) the rigid ice cylinder collision with the rigid or elastic structural plate at different collision velocities, (2) the elastic ice cylinder collision with the rigid or elastic structural plate at different collision velocities and (3) the elastoplastic ice cylinder collision with the rigid or elastic structural plate at different collision velocities. The numerical results show that: (1) the hydrodynamic influences are negligible in the first case, (2) the hydrodynamic influences in the second and third cases are not negligible, and become very significant in the third case. The influences are numerically estimated to be in the range of 20%–60% in terms of the momentum change. If the ice response is approximately decomposed into the rigid-body motions and the deformation modes at the instant of the collision with the structure, the previous conclusions show that the hydrodynamic influences on the rigid-body motions of the ice are negligible, but those on the elastic and elastoplastic modes of the ice are significant. Comparison with the case of a submerged ice cylinder (although not a practical case) reveals that the hydrodynamic influences are small in the first case due to the fact that the energy loss is used to produce the water splash and the cavity behind the ice cylinder. Through this study we come into the conclusion that the hydrodynamic influences are not important for the rigid-body motions, but important for the elastic or elastop

关键词： Ice-structure collision hydrodynamic influence numerical rigid mode elastic mode

Tailoring microenvironment for efficient CO_(2)electroreduction through nanoconfinement strategy

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nano Research 2024年第9期17卷 7880-7899页

作者： Lulu Chen Minhan Li jia-nan Zhang Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation Country College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China

The electrocatalytic conversion of CO_(2)to produce fuels and chemicals holds great promise,not only to provide an alternative to fossil feedstocks,but also to use renewable electricity to convert and recycle the greenhouse gas CO_(2)to mitigate climate ***,the selectivity and reaction rates for the conversion of CO_(2)into desirable carbon-based products,especially multicarbon products with high added value,are still insufficient for commercial applications,which is attributed to insufficiently favourable microenvironmental conditions in the vicinity of the *** construction of catalysts/electrodes with confined structures can effectively improve the reaction microenvironment in the vicinity of the electrodes and thus effectively direct the reaction towards the desired *** this review,we firstly introduce the effects of the microenvironment at the electrode-electrolyte interface including local pH,local intermediate concentration,and local cation concentration on CO_(2)reduction reaction(CO_(2)RR)as well as the mechanism of action,and then shed light on the microenvironmental modulation within the confined space,and finally and most importantly,introduce the design strategy of CO_(2)RR catalyst/electrode based on the confinement effect.

关键词： CO_(2)reduction reaction microenvironment confinement effect catalyst design

Spin-orbit interaction induced Casimir-Lifshitz torque between two-dimensional electron gases

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 134-142页

作者： jia-nan Rong Liang Chen Kai Chang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China School of Mathematics and Physics North China Electric Power UniversityBeijing 102206China School of Physics Zhejiang UniversityHangzhou 310027China College of Materials Science and Opto-electronic Technology University of Chinese Academy of SciencesBeijing 100049China

We investigate theoretically the Casimir interaction between two parallel two-dimensional electron gases(2DEGs)with Rashba and Dresselhaus spin-orbit interactions(SOIs),based on the quantum field *** derive an analytical expression for the polarization tensor and obtain the solution to the motion equation of the electromagnetic(EM)*** calculate the CasimirLifshitz torque(CLT)between two parallel 2DEGs with Rashba and Dresselhaus SOIs,which can be tuned by changing the relative strength between two *** anisotropic Casimir energy between 2DEGs caused by the interplay between the SOIs of 2DEGs offers a new origin of CLT and a new type of optoelectronic device.

关键词： Casimir torque two-dimensional electron gas spin-orbit interaction

Strengthening mechanisms of reduced activation ferritic/martensitic steels:A review

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 335-348页

作者： Jin-hua Zhou Yong-feng Shen nan jia Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China The State Key Lab of Rolling&Automation Northeastern UniversityShenyang 110819China

This review summarizes the strengthening mechanisms of reduced activation ferritic/martensitic(RAFM)***-angle grain boundaries,subgrain boundaries,nano-sized M_(23)C_(6),and MX carbide precipitates effectively hinder dislocation motion and increase high-temperature strength.M23C6 carbides are easily coarsened under high temperatures,thereby weakening their ability to block *** properties are improved through the reduction of M23C6 ***,the loss of strength must be compensated by other strengthening *** review also outlines the recent progress in the development of RAFM *** dispersion-strengthened steels prevent M23C6 precipitation by reducing C content to increase creep life and introduce a high density of nano-sized oxide precipitates to offset the reduced *** plastic deformation methods can substantially refine subgrains and MX carbides in the *** thermal deformation strengthening of RAFM steels mainly relies on thermo-mechanical treatment to increase the MX carbide and subgrain *** procedure increases the creep life of TMT(thermo-mechanical treatment)9Cr-1W-0.06Ta steel by~20 times compared with those of F82H and Eurofer 97 steels under 550℃/260 MPa.

关键词： reduced activation ferritic/martensitic steel strengthening mechanism high-angle grain boundary subgrain boundary precipitate

A microfluidic approach for development of hybrid collagen-chitosan extracellular matrix-like membranes for on-chip cell cultures

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Journal of Materials Science & Technology 2021年第4期63卷 54-61页

作者： Erica Rosella nan jia Diego Mantovani Jesse Greener Laboratory Department of ChemistryLaval UniversityQuébecQCCanada Laboratory of Biomaterials and Bioengineering CRC-1Dept.Min-Met-Materials Eng&CHU de QuebecResearch CenterLaval UniversityQuébecQCCanada CHU de Quebec Research Centre Laval University10 rue de l’EspinayQuébecQC G1L 3L5Canada

To advance organ-on-a-chip development and other areas befitting from physiologically-relevant biomembranes,a microfluidic platform is presented for synthesis of biomembranes during gelation and investigation into their role as extracellular matrix *** this work,high-throughput studies of collagen,chitosan,and collagen-chitosan hybrid biomembranes were carried out to characterize and compare key properties as a function of the applied hydrodynamic conditions during ***,depending on the biopolymer material used,varying flow conditions during biomembrane gelation caused width,uniformity,and swelling ratio to be differently affected and ***,cell viability studies of seeded fibroblasts were conducted,thus showing the potential for biological applications.

关键词： matrix swelling showing

Decentralized Robust Energy Management of Multi-area Integrated Electricity-gas Systems

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Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1478-1489页

作者： nan jia Cheng Wang Wei Wei Tianshu Bi IEEE State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Department of Electrical Engineering Tsinghua University

This paper proposes a fast and decentralized solution methodology for the robust operation of multi-area integrated electricity-gas systems(M-IEGSs).A deterministic reformulation is obtained for the two-stage robust model by applying the linear decision rule based electrical reserve utilization scheme as well as regulating the distributed gas *** linear approximations are developed for the nonconvex Weymouth equation in the gas network to determine the gas flow *** penalty convex-concave procedure(P-CCP)is then adopted to refine a feasible local optimum for the nonconvex model with an acceleration *** decentralized decision-making is enabled by the alternating direction multipliers method(ADMM).The convergence as well as computation performance of the overall solution procedure can be guaranteed as only convex optimizations are *** results validate the effectiveness of the proposed methods as well as the benefits of the proposed convex programing based solution procedure.

关键词： Convex optimization decentralized robust optimization energy management linear approximation integrated electricity-gas system

Universal dynamic scaling and Contact dynamics in quenched quantum gases

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Frontiers of physics 2024年第2期19卷 213-220页

作者： jia-nan Cui Zhengqiang Zhou Mingyuan Sun School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China

Recently universal dynamic scaling is observed in several systems,which exhibit a spatiotemporal self-similar scaling behavior,analogous to the spatial scaling near phase *** latter one arises from the emergent continuous scaling *** by this,we investigate the possible relation between the scaling dynamics and the continuous scaling symmetry in this *** derive a theorem that the scaling invariance of the quenched Hamiltonian and the initial density matrix can lead to the universal dynamic *** is further demonstrated both in a two-body system analytically and in a many-body system *** the latter one,we calculate the dynamics of quantum gases quenched from the zero interaction to a finite interaction via the non-equilibrium high-temperature virial expansion.A dynamic scaling of the momentum distribution appears in certain momentum-time windows at unitarity as well as in the weak interacting ***,this universal scaling dynamics persists approximately with smaller scaling exponents even if the scaling symmetry is fairly *** findings may offer a new perspective to interpret the related *** also study the Contact dynamics in the BEC−BCS ***,the half-way time displays a maximum near unitarity while some damping oscillations occur on the BEC side due to the dimer state,which can be used to detect possible two-body bound states in experiments.

关键词： dynamic scaling Contact dynamics quantum gases cold atom quench dynamics virial expansion continuous scaling symmetry