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High performance wide frequency band triboelectric nanogenerator based on multilayer wave superstructure for harvesting vibration energy

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Nano Research 2023年第5期16卷 6933-6939页

作者： Song Tang Wenxuan Chang Gui Li Jianfeng Sun Yan Du Xindan Hui Qian Tang Zhihao Hu Jiaqi Li Jie Chen Wencong He Hengyu Guo School of Physics Chongqing UniversityChongqing 400044China College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 400047China

Efficiently converting the random vibration energy widely existed in human activities and natural environments into electricity is significant to the local power supply of sensor nodes in the internet of things.However,the conversion efficiency of energy harvester is relatively low due to the limitation of device’s intrinsic frequency.In this work,a multi-layered,wavy super-structuredtriboelectric nanogenerator(SS-TENG)is designed,whose output performances can be greatly promoted by combining the charge excitation mechanism.The steel sheet acts not only as an electrode but also as a supporter for the overall frame of SSTENG,which effectively improves the space utilization rate and results in a volume charge density up to 129 mC·m^(−3).In addition,the resonant frequency width of the SS-TENG can be widened by changing the parameters of the superstructure.For demonstration,the SS-TENG can sustainably drive two temperature and humidity sensors in parallel by harvesting vibration energy.This work may provide an effective strategy for harvesting vibration energy and broadening frequency response.

关键词： charge excitation superstructure vibration energy volume charge density resonant frequency

Effects of non-liquefiable crust layer and superstructure mass on the response of 2×2 pile groups to liquefaction-induced lateral spreading

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2701-2719页

作者： S.Mohsen Haeri Morteza Rajabigol Saman Salaripour Hiwa Sayaf Milad Zangeneh Department of Civil Engineering Sharif University of TechnologyTehranIran

In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spreading.In this regard,an inclined base layer overlain by a very loose liquefiable layer was constructed in both models;while only in one model,a non-liquefiable crust layer was built.A lumped mass,being representative of a superstructure,was attached to the cap of one pile group in both models.The models were fully instrumented with various sensors,including acceleration,displacement,and pore water pressure transducers.Also,the piles were instrumented with pair strain gauges to measure pure bending moments induced by cyclic and monotonic loadings associated with ground shaking and lateral spreading,respectively.The results showed that the existence of the non-liquefiable crust layer increases both the maximum and residual soil displacements at the free field and also the maximum bending moments in the piles.The results of the experiments indicated that the crust layer induces a high kinematic lateral soil pressure and force on the piles which are not present in the crustless case.The crust layer increases the pile cap displacement before liquefaction,albeit decreases it after liquefaction,due to the elastic rebound of the piles in the liquefiable layer.The crust layer postpones both liquefaction triggering and dissipation of excess pore water pressure.The existence of the superstructure mass on the pile caps decreases the acceleration amplitude of the pile caps,while increases their maximum displacement.

关键词： Soil liquefaction Lateral spreading 1g shake table test Pile group Crust layer superstructure

Random Differential Settlement Effects on Reliability of Existing Bridges

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Journal of Civil Engineering and Architecture 2024年第2期18卷 60-68页

作者： Zuo-Cai Wang Department of Civil Engineering Hefei University of TechnologyHefei 230009Anhui ProvinceChina

This paper investigates the impact of differential foundation settlement on the reliability of bridge superstructure based on loads and resistances statistical properties in Missouri State.Maximum deterministic differential settlement is often used in current AASHTO LRFD(load and resistance factored design)specification.However,the expected foundation settlement is quite different from the actual settlement due to the soil’s large variability.Therefore,it makes sense to consider settlement as a random variable.In this paper,a lognormal distribution with coefficient of variation of 0.25 of random settlement is considered in reliability analysis based on limited previous studies.Dead and live loads are modeled as random variables with normal and Gumbel Type I distributions,respectively.Considering the regional traffic condition on Missouri roadways,the live load effect on existing bridges based on weight-in-motion data is also investigated.The calibrated resistance statistical properties such as bias and COV(coefficient of variance)are used for reliability analysis.Total 14 existing bridges based on Strength I Limit State are analyzed.Since no differential settlement is considered in the past designed bridges in Missouri,small differential settlement can significantly reduce the reliability indices of the superstructure,depending upon the span length and rigidity of the girder.The analysis results also show that the reliability of existing steel-girder bridges is consistently higher than prestressed concrete and solid slab bridges;the shorter and stiffer the spans,the more significant the settlement’s effect on the reliability of bridge superstructures;As the span length ratio becomes less than 0.75,the girder and solid slab bridges’reliability drops significantly at small settlements.

关键词： Bridges superstructure LRFD

Study on superstructure in ion co-doped BiFeO_3 by using transmission electron microscopy

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Chinese Physics B 2015年第4期24卷 290-295页

作者：蒲十周郭超李美亚陈珍莲邹化民 Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan University Center for Electron Microscopy Wuhan University Ningbo Institute of Material Technology and Engineering Chinese Academy of Sciences

La3＋ and V5＋ co-doped BiFeO3 ceramics are synthesized by rapid liquid sintering technique. The modulated structure in Bi0.85La0.15Fe0.97V0.03O3 is investigated by using transmission electron microscopy （TEM）. Two kinds of superstructures are observed in the samples. One is the component modulated superstructure and twin-domain, which is generated by La3＋ ordered substitution for Bi3＋ and frequently appears. The chemical composition of the superstructure is explored by x-ray energy dispersive spectroscopy （EDS）. The model of the ordered structure is proposed. Simulation based on the model is conducted. The second is the fluorite-type δ-Bi2O3 related superstructure. The relation between the ferroelectric property and the microstructure of the sample is also discussed.

关键词： multiferroic materials superstructure co-doped rapid liquid sintering technique

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Numerical Simulation of Welding Deformation for Hull superstructure Steel Based on the Finite Element Analysis

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Journal of Materials Science & Technology 2003年第Z1期19卷 212-214页

作者： Liu L. Liang G. Liu Y. Zhan Z. Dalian Univ. of Technol. Dalian 116024 China Lab. of Adv. Welding Technol. Harbin Inst. of Technol. Harbin 150001 China Dalian Dockyard Dalian 116020 China

Using finite analysis element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal physical properties changes were depended on the temperatureand the heat loss on the surface. At the same time, it analyzed the influence of the deformation and stress, whichgenerated in the plate butt-welding process, to the superstructure steel welding deformation. The result showedthat the deformation and stress generated in the steel plate butt-welding process are considered to be the mainfactors to influence the welding deformation of superstructure steel. It found the effective ways to reduce the weldingdeformation of the hull superstructure steel is to relieve the butt-welding deformation and release butt-welding stressbefore welding the hull superstructure steel.

关键词： Hull superstructure steel, Finite element analysis, Welding deformation

Simultaneous synthesis of sub and above-ambient heat exchanger networks including expansion process based on an enhanced superstructure model

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1344-1356页

作者： Yu Zhuang Rui Yang Lei Zhang Jian Du Shengqiang Shen Institute of Process Systems Engineering School of Chemical EngineeringDalian University of TechnologyDalian 116023China Key Laboratory of Liaoning Province for Desalination School of Energy and Power EngineeringDalian University of TechnologyDalian 116023China

Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion through valves barely affects heat integration.In addition,expansion through expanders at higher temperature produces more work,but consumes more hot utility.Therefore,there is a need to weigh work production and heat consumption.To this end,an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages.A mixed-integer nonlinear programming(MINLP)model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion,which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement.Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost.Four example studies are conducted with two distinct objective function(minimization of exergy consumption and total annual cost,respectively)to illustrate the feasibility and efficacy of the proposed method.

关键词： superstructure Heat exchanger networks Expansion Exergy Economics Mathematical modeling

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A New Three-Dimensional superstructure in Bafertisite

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Acta Geologica Sinica(English Edition) 2011年第5期85卷 1028-1035页

作者： LI Guowu~*,XIONG Ming,SHI Nicheng and MA Zhesheng Crystal structure laboratory,National Laboratory of Mineral Materials,China University of Geosciences (Beijing),Beijing 100083,China Crystal structure laboratory National Laboratory of Mineral Materials China University of Geosciences (Beijing) Beijing 100083 China

A new superstructure was found in bafertisite[(Ba;Na;);(Fe;Mn;Mg;);TiO [(Si;Ti;Al;Cr;);O;](OH;F;Cl;);]from Donghai County,Jiangsu Province,China.The occurrence of the superstructure reflections were observed by single crystal diffraction using a SMAR APEX CCD.The a;,b;and c;axis directions revealed extra weak reflection spots of the superstructure.The apparent 2a,2b and 2c superstructure is monoclinic with unit cell a=10.6502（15） A,b= 13.7233（19）A,c=21.6897（3）A,α=90°,β=94.698（3）°,γ=90°,space group Cm,Z=16.If c;extra weak reflections are ignored,the secondary supercell gave a cell a=10.6548（15）A,b=13.7284（19）A,c = 11.6900（17）A,α=90°,β=112.322（28）°,γ=90°,space group Cm,Z=8.The basic subcell was obtained by ignoring all extra weak reflection spots and gave:a=5.3249（17）A,b=6.8669（22）A,c=10.8709（36） A,α=90°,β=94.740（62）°,γ=90°,space P2;/m,Z=2.The superstructure has been refined to R = 0.063 for 7805[R;= 0.0266]unique reflections I>2δ（I）.The structure consists of an octahedra（O） sheet sandwiched between two heteropolyhedral（H） sheets.These sheets consist of Ti-octahedra and twin tetrahedral disilicate groups[Si;O;].The O sheet comprises（Fe,Mg）O;octahedra.The large Ba cation is located in the interlayer area.The refined structure shows Fe,Mg are partly ordered.The shifting of the TiO;octahedron and SiO;tetrahedron sites in the sheet may be a consequence of the superstructure.

关键词： bafertisite superstructure crystal structure layered titanium silicate

Submonolayer Eu superstructures—A class of 2D magnets

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Nano Research 2023年第1期16卷 1500-1506页

作者： Dmitry V.Averyanov Ivan S.Sokolov Alexander N.Taldenkov Oleg E.Parfenov Andrey M.Tokmachev Vyacheslav G.Storchak National Research Center“Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Two-dimensional(2D)magnetic materials promise unconventional properties and quantum phases as well as advances in ultracompact spintronics.Miniaturization of 2D magnets often reaches a single monolayer but in general can go beyond this limit,as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with Si.The question is whether the submonolayer magnetism constitutes a general phenomenon.Herein,we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures,stoichiometries,and chemical bonding.We synthesized and studied a set of Eu superstructures on Ge(001).Their magnetic properties are consistent with the emergence of a magnetic order such as ferro-or ferrimagnetism.In particular,control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the magnetism.Taken together,Eu/Ge and Eu/Si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.

关键词： two-dimensional(2D)magnetism submonolayer superstructure surface reconstruction germanium

Evolution of incommensurate superstructure and electronic structure with Pb substitution in(Bi2-xPbx)Sr2CaCu2O8+δ superconductors

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Chinese Physics B 2019年第7期28卷 102-110页

作者：刘静赵林高强艾平张璐谢涛黄建伟丁颖胡成闫洪涛宋春尧徐煜李聪蔡永青戎洪涛吴定松刘国东王庆艳黄元张丰丰杨峰彭钦军李世亮杨槐馨李建奇许祖彦周兴江 Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China Songshan Lake Materials Laboratory Dongguan 523808 China Collaborative Innovation Center of Quantum Matter Beijing 100871 China

High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors.

关键词： Bi2-xPbxSr2CaCu2O8+δ superstructure electronic structure angle-resolved photoemission spectroscopy(ARPES) modulation

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