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Preparation and properties of bifunctional Gd_(2)O_(3)/GQD composite nanoparticles

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Journal of Rare Earths 2022年第7期40卷 1118-1125页

作者： Chengjie xu Meigui ou Hao Zhou Chunlin Yang College of Materials and Metallurgy University of GuizhouGuiyang 550025China National Local Co-construction Engineering Laboratory for High Performance Metal Structure Material and Manufacture Technology Guiyang 550025China College of Chemistry and Materials Engineering Guiyang UniversityGuiyang 550003China

Nanocomposites of graphene quantum dots(GQDs)modified gadolinium oxide(Gd_(2)O_(3))particles were successfully synthesized.In addition,the effects of the amount of GQDs and the particle size of Gd_(2)O_(3)on the properties of nanocomposites were investigated.The structures and properties of nanoparticles were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,field emission scanning electron microscopy,transmission electron microscopy,photoluminescence spectrometry,and magnetic resonance imaging.The results show that the synthesized particles Gd_(2)O_(3)/GQD are spherical with a diameter of approximately 40 nm and have excellent fluorescence and magnetic property,and its relaxation rate(r_(1)=25.18(mmol/L)^(-1)/s)is higher than that of the typical commercial contrast agents Gd-DTPA(r_(1)=4.5(mmol/L)^(-1)/s),The fluorescence property of Gd_(2)O_(3)/GQD is optimized by varying the V_(GQDs):V_(Gd2O3)ratio,and 1:1 ratio of V_(GQDs):V_(Gd2O3)results in the best fluorescence property.The large particles of Gd_(2)O_(3)improve the relaxation property of nanocomposites.Therefore,the nanocomposites Gd_(2)O_(3)/GQD with magnetic and fluorescence characteristics can be used in biological imaging,drug targeting,and in-vivo diagnostic analysis.

关键词： Gd_(2)O_(3)/GQD Magnetic Fluorescence Magnetic resonance imaging(MRI) Rare earths

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Highly active and stable Cu_(9)S_(5)-MoS_(2)heterostructures nanocages enabled by dual-functional Cu electrocatalyst with enhanced potassium storage

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Journal of Materials Science & Technology 2023年第12期143卷 107-116页

作者： Bao Zhang Baohe xu Haozhe Qin Liang Cao Xing ou Engineering Research Center of the Ministry of Education for Advanced Battery Materials School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China

The intrinsic poor electrical conductivity,severe dissolution of K x S y intermediates,and inferior conversion reaction reversibility extremely impede the practical application of the transition-metal chalcogenides(TMDs)anode for potassium-ion batteries(PIBs).Herein,a rationally designed Cu_(9)S_(5)/MoS_(2)/C heterostruc-ture hollow nanocage was synthesized with assistance from metal-organic frameworks(MOFs)precursor.During the K-storage process,the homogeneously distributed the sulfiphilic nature of Cu 0 reaction prod-uct could act as a dual-functional catalyst,not only facilitating the rapid charge transfer but also effec-tively anchoring(K x S y)polysulfides,thus boosting K-storage reactions reversibility during the conversion reaction process.When applied as an anode for PIBs,the as-prepared heterostructure exhibits excellent reversible capacity and long cycle lifespan(350.5 mAh g^(-1)at 0.1 A g^(-1)and 0.04%per cycle capacity de-cay at 1 A g^(-1)after 1000 cycles).Additionally,the potassium storage mechanism is distinctly revealed by in-situ characterizations.The nanoarchitecture designing strategy for the advanced electrode in this work could provide vital guidance for relevant energy storage materials.

关键词： Nanocage hollow structure Metal-organic frameworks Cu_(9)S_(5)-MoS_(2)heterostructure Dual-functional catalyst Potassium-ion batteries

Simulating multiple urban land use changes by integrating transportation accessibility and a vector-based cellular automata:a case study on city of Toronto

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Geo-Spatial Information Science 2022年第3期25卷 439-456页

作者： Xiaocong xu Dachuan Zhang Xiaoping Liu Jinpei ou Xinxin Wu School of Geography and Planning Guangdong Key Laboratory for Urbanization and Geo-simulationSun Yat-Sen UniversityGuangzhouChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiChina

The accessibility provided by the transportation system plays an essential role in driving urban growth and urban functional land use changes.Conventional studies on land use simulation usually simplified the accessibility as proximities and adopted the grid-based simulation strategy,leading to the insufficiencies of characterizing spatial geometry of land parcels and simulating subtle land use changes among urban functional types.To overcome these limita-tions,an Accessibility-interacted Vector-based Cellular Automata(A-VCA)model was proposed for the better simulation of realistic land use change among different urban functional types.The accessibility at both local and zonal scales derived from actual travel time data was considered as a key driver of fine-scale urban land use changes and was integrated into the vector-based CA simulation process.The proposed A-VCA model was tested through the simulation of urban land use changes in the City of Toronto,Canada,during 2012-2016.A vector-based CA without considering the driving factor of accessibility(VCA)and a popular grid-based CA model(Future Land Use Simulation,FLUS)were also implemented for compar-isons.The simulation results reveal that the proposed A-VCA model is capable of simulating fine-scale urban land use changes with satisfactory accuracy and good morphological feature(kappa=0.907,figure of merit=0.283,and cumulative producer’s accuracy=72.83%±1.535%).The comparison also shows significant outperformance of the A-VCA model against the VCA and FLUS models,suggesting the effectiveness of the accessibility-interactive mechanism and vector-based simulation strategy.The proposed model provides new tools for a better simula-tion of fine-scale land use changes and can be used in assisting the formulation of urban and transportation planning.

关键词： Urban land use change simulation transportation accessibility Vector-based cellular automata(VCA)

Obstacle avoidance in human-robot cooperative transportation with force constraint

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Science China(Information Sciences) 2023年第1期66卷 334-335页

作者： Ying ZHANG Chenguang YANG Sheng xu Yongsheng ou College of Automation Science and Engineering South China University of Technology Guangdong Provincial Key Lab of Robotics and Intelligent System Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences

Dear editor,Robots are often conceived as human-like machines that can interact with humans naturally and safely. Human-robot interaction means that robots can communicate with people,understand their needs, and act accordingly [1]. This interaction is critical when two people are needed to finish a task cooperatively.

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Efficacy and Safety of Acupuncture Combined with Yishen Granule in Elderly Adults with Mild Cognitive Impairment: A Multicenter, Randomized Controlled Trial

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Efficacy and Safety of Acupuncture Combined with Yishen Gran...

Improvement in resolution of fiber-laser photoacoustic tomography based on a virtual-point concept

中国睡眠研究会第十五届全国学术年会

作者： ou Li xu Jian 上海市中医医院

Objective: Mild cognitive impairment(MCI) is a clinical disease that is prevalent in the elderly.Traditional Chinese herbs(TCHs) and acupuncture are valuable therapeutic options for MCI.This study aimed to assess the efficacy and safety of acupuncture and Yishen Granule(YSG) in restoring cognitive function in elderly patients with MCI.Methods: A multicenter, randomized, double-blind, parallel-group, controlled trial(8-week intervention) was conducted at two tertiary hospitals in Shanghai, China.A total of 120 participants were randomly divided into four groups(n = 30 per group): A, acupuncture with YSG;B, acupuncture with placebo herbal medicine;C, sham acupuncture with YSG;D, sham acupuncture with placebo herbal medicine.The primary outcome was a change in Montreal Cognitive Assessment(MoCA), while the secondary outcome was to evaluate improvement in the MiniMental State Examination(MMSE).Assessments were conducted at baseline and weeks 4 and 8.Results: Of the 120 patients(69.17 ± 6.57 years;71 women [59.17%] and 49 men [40.83%]) included in the study, 106(88.33%) completed the study.Two-way repeated measures ANOVA showed that the MoCA and MMSE scores in group A were significantly different from those in group D at week 4(Poups A, B, and C were significantly improved compared with those in group D(P oup A was significantly greater than those in groups B and C (Pous adverse events were reported.Conclusions: Acupuncture, YSG, and the combination of both improved cognitive function, with the combined therapy being the most effective, which can be beneficial in preventing dementia and improving the quality of life of the elderly.

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来源： cnki会议评论

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Visual Computing for Industry,Biomedicine,and Art 2021年第1期4卷 22-28页

作者： xue Bai xu Li Jun Ma Bai-ou Guan Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics TechnologyJinan UniversityGuangzhou 511443China

In this study,a virtual-point concept was introduced into fiber-laser photoacoustic tomography to improve the elevational image resolution.The flexible fiber laser was bent into an arc shape to conform to the ultrasound wavefront,which formed an ultrasound focus at the center of the arc.The synthetic aperture focusing technique was utilized to reconstruct the images;as a result,the elevational resolution particularly within the out-of-focus region was considerably improved compared to the resolution of an image retrieved by multiplexing the PA time-resolved signals with sound velocity.The all-optical fiber-laser photoacoustic tomography system with a high spatial resolution has potential for various applications,including biomedical research and preclinical/clinical diagnosis.

关键词： Photoacoustic tomography Fiber laser Virtual point Synthetic aperture focusing

Gene-like Precise Construction of Functional DNA Materials

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Accounts of Materials Research 2022年第1期3卷 42-53页

作者： Chi Yao Yuwei xu Pin Hu Junhan ou Dayong Yang Frontiers Science Center for Synthetic Biology Key Laboratory of Systems Bioengineering(MOE)Institute of Biomolecular and Biomedical EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350P.R.China

CONSPECTUS:Developing a new system of material chemistry is an important molecular foundation for the design and preparation of functional materials,which resembles the preparation of raw materials such as bricks for constructing a building that determines the quality of the building.However,precisely controlling the synthesis processes and structures of functional materials always remains a grand challenge.It is expected to propose a paradigm of“gene-like”precise construction to realize the rational synthesis of functional materials,i.e.,a“structure-function-application”principle for the precise construction.As the core genetic material of life,the DNA molecule is a bioactive macromolecule that can accurately encode genetic information and also can act as the generic molecular building block for the precise construction of functional materials.In this Account,we describe our work on the design and construction of functional DNA materials,to illustrate the principle of“gene-like”construction of functional DNA materials.The DNA molecule shows the unique advantages in the“gene-like”construction of functional materials,mainly including the precise arrangement of bases(monomers),the controllable design and assembly of structure,the precise transmission of sequence information,and customization of function.First,the number and sequence of four deoxynucleotide monomers that constitute the DNA strand can be rationally designed and accurately synthesized.Second,the sequence information on DNA endows the precise and efficient assembly of DNA molecules and ensures the precise regulation on the specific biological functions of functional DNA materials.Third,the functions of DNA materials can couple with the biological environments,so as to achieve the predetermined applications.Based on the scale of the constructed DNA materials,we categorize DNA materials into three classes:molecular scale,nanoscale,and macroscale.At the molecular scale,the representative material is branched DNA-based materials;the construction strategies

关键词： materials. precise synthesis

Structural Optimization of Polyimide Foam via Composition with Hyperbranched Polymer Modified Fluorinated Carbon Nanotubes

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Chinese Journal of Polymer Science 2023年第1期41卷 117-128页

作者： Jian Liu Zhuang Nie Rui Qin An-Ping ou Tao Zhang xu Wang Xiang-Yang Liu College of Polymer Science and Engineering State Key Laboratory of Polymer Material and EngineeringSichuan UniversityChengdu610065China Zhejiang Key Laboratory of Marine Materials and Protective Technologies Key Laboratory of Marine Materials and Related TechnologiesCASNingbo315000China

The key to improve the foam’s performance is to optimize the cellular structure and its bulk-material composition.Here,the hyperbranched polymer modified fluorinated multi-walled carbon nanotube(HPMCNT-F)based on the nucleophilic reactions of MCNT-F was successfully prepared and used to composite with PI foams.The pristine MCNT shows a poor dispersity and weak interfacial interaction with PI matrix.While HPMCNT-F exhibits an excellent dispersity and effectively forms covalent/non-covalent interaction with PI matrix due to the surface-structure engineering,resulting in the enhancement of the PI bulk.Furthermore,HPMCNT-F works as a heterogeneous nucleation agent in PI foam to optimize the cellular structure.The enhancement of PI bulk and the optimizing of cellular structure result in the increase of compressive special strength of composite foam by 58.9%with a low loading of 1.6 wt%HPMCNT-F.Moreover,the hyperbranched polymers effectively prevent the thermal conduction among HPMCNT-F,and the isolated MCNTs effectively block thermal radiation through absorption and reflection the infrared waves.Thus,the thermal conductivity was reduced by 8.0%simultaneously.

关键词： Foams Nanocomposites Mechanical properties Thermal properties

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Numerical Simulation of Stress Field in Physical Tempering Process of Flat Soda Lime Silica Glass

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 20-30页

作者：刘超英 HE Dongsheng ou Yingchun HE Feng HAO Lizi xu Shaokun MA Juanrong China Building Materials Academy Beijing 100024China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China China Helicopter Research and Development Institute Jingdezhen 333001China

Based on the analysis of different theory for glass tempering process,the“structural theory”with stress relaxation and structural relaxation effects was selected to investigate the tempering of flat glass quantificationally.The geometrical model with small size and non-homogeneous mesh were considered to build the finite element models according to the characteristics of stress field.The tempering process of flat glass with12 mm thickness was calculated with the verified finite element model.The transient and permanent stress of the central area,edge and corner end of the flat glass are obtained and analyzed.From the calculation results of basic case,the transient tensile stress at the upper surface of the central area,the center point of edge,the edge of edge,the edge of corner were 14.30,18.94,40.76 and 34.75 MPa,respectively.The transient tensile stress at these points were dangerous to promote the glass to break during the tempering.In addition,the point at the diagonal line of symmetry plane in the thickness direction,which is 14 mm from corner,has the maximum permanent tensile stress about 70.01 MPa in the flat glass after tempering.Thus,it is indicated that the corner is the weakest region in the tempered glass.

关键词： nite element tempering stress relaxation structural relaxation compressive stress tensile stress

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