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The transport and retention of CQDs-doped TiO_(2) in packed columns and 3D printed micromodels

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Journal of Environmental Sciences 2022年第3期34卷 365-375页

作者： Tao Sun Jian Song zhen Liu wei Jiang Environment Research Institute Shandong UniversityQingdao 266237China Qingdao SKSS 3D Printing Technology Co.LTD. Qingdao 266111China Shenzhen Research Institute Shandong UniversityShenzhen 518057China

CQDs-doped TiO_(2)(C-TiO_(2))has drawn increased attention in recent because of its excellent catalytic *** the transport of C-TiO_(2)in porous media is necessary for evaluating the environmental process of this new *** experiments were used in this study to investigate ionic strength(IS),dissolved organic matter(DOM)and sand grain size on the transport of C-TiO_(2).The mobility of C-TiO_(2)was inhibited by the increased IS and decreased sand grain size,but was promoted by the increased DOM *** promotion efficiency of DOM ranked as humic acid(HA)>alginate(Alg)>bovine serum albumin(BSA),which was in the same order as their ability to change surface *** micromodels of pore network were prepared via 3D printing to further reveal the deposition mechanisms and spatial/temporal distribution of C-TiO_(2)in porous space.C-TiO_(2)mainly attached to the upstream region of collectors because of *** collector ripening was observed after long-time *** existence of DOM caused visible decrease of C-TiO_(2)deposition in the pore *** caused the most remarkable reduce of deposition in the three types of DOM,which was consistent with the column experiment *** research is helpful to predict the transport of C-TiO_(2)in natural porous media.

关键词： CQDs-doped HO_(2) Transport Dissolved organic matter Column experiment 3D-printed micromodel

Boosting stability of inverted perovskite solar cells with magnetron-sputtered molybdenum rear electrodes

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Rare Metals 2023年第11期42卷 3741-3754页

作者： Zhao-Yi Jiang ming Pan Fu-Meng Ren Rui Chen zhen-Xing Sun Zhi-Chun Yang Zong-Hao Liu wei Chen Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China Optics Valley Laboratory Hubei430074China C Innovation Laboratory Contemporary Amperex Technology Ltd.Ningde352100China State Key Lab of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan030006China

Perovskite solar cells(PSCs)have attracted widespread attention because of their remarkable efficiency,low cost,and ease of ***,the operational stability of the PSCs still suffers from the corrosion of metal electrodes induced by metal-halide ***,we propose a feasible strategy for improving the stability of inverted PSCs by using magnetron-sputtered Mo rear *** with a bismuth(Bi)buffer layer prepared by thermal evaporation,the damage from the magnetron sputtering process toward the underlayers can be effectively ***,based on the Bi+Mo bilayer electrode,the inverted PSCs with a NiMgLiO hole transport layer exhibited a power conversion efficiency(PCE)of 18.82%.In addition to their excellent stability at high temperatures,compact Mo films can inhibit the decomposition of Perovskite(Pvk)films in the *** PSCs with the Bi/Mo bilayer electrode maintained 97.9%of its initial efficiency,showing better stability than PSCs with the traditional Ag electrode after aging for 3000 h under continuous light illumination.

关键词： Perovskite solar cells(PSCs) Magnetron sputtering Rear electrodes Molybdenum Stability

Influence of night-time light pollution on the photosynthesis and physiological characteristics of the urban plants Euonymus japonicus and Rosa hybrida

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Ecological Processes 2023年第1期12卷 534-544页

作者： Yaxi wei zhen Li Jiaolong Zhang Dan Hu State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China Department of Water Ecology and Environment China Institute of Water Resources and Hydropower ResearchBeijing 100038China

Background Night-time light pollution(NLP),which breaks the natural cycle of day and night,has become a new threat to urban *** are the main component of urban ecosystems and play an irreplaceable role in maintaining urban ecological *** effects of NLP with various radiation sources,including green,white,blue and red light provided by light-emitting diodes,on urban plants,Euonymus japonicus and Rosa hybrida,were examined in a block field *** NLP caused photoinhibition and oxidative stress in plants,and the extent of the deleterious effects varied with the spectral distribution of artificial light sources and *** *** and *** were more sensitive to blue and red light,which reduced the pigment concentration,net photosynthetic rate,stomatal limit value,effective quantum yield,apparent electron transfer rate and photochemical quenching coefficient,and markedly increased the malondialdehyde content and total antioxidant ***,those negative effects under white light were only present in *** and not in ***,blue and red light significantly decreased the stomatal conductance of *** contrast,green light had no significant effect on the above indices for both *** spectra did not significantly change the sugars and starch contents for either *** Considering that the spectral distribution of artificial light at night in cities has great heterogeneity and that its effect varies with plant species,it is important to arrange tree species with NLP tolerance and install appropriate light sources in urban areas based on the corresponding physiological responses and adaptation of urban trees.

关键词： Light pollution Urban plant Spectra Photosynthetic parameter Physiological characteristics

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Microstructure and properties of Al–7Si–0.6Mg alloys with different Ti contents deposited by wire arc additive manufacturing

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Rare Metals 2021年第9期40卷 2530-2537页

作者： Cheng-De Li Hui-Min Gu wei Wang Shuai Wang Ling-Ling Ren Yu-Chun Zhai zhen-Biao Wang Zhu ming School of Metallurgy Northeastern UniversityShenyang 110006China Research Laboratory of WAAM Process Inner Mongolia Metal Material Research InstituteNingbo 315100China Technology Department North East Industrial Materials and Metallurgy Co.Ltd.Fushun 113200China

Numerous studies have addressed the advantages of wire arc additive manufacturing for manufacturing aluminum alloys. However, the role of Ti content in aluminum alloys has rarely been discussed. Herein, the effect of Ti content on the microstructure and properties of Al–7 Si–0.6 Mg alloys was studied. The alloys were deposited via wire arc additive manufacturing and were examined through optical microscopy(OM), scanning electron microscopy(SEM), and electronic universal testing. The results show that the increase of Ti content gradually promotes the increase of the secondary dendrite arm spacing and also has an increasing tendency to form pores defect in the as-deposited alloys. The change of titanium content also affects the difference between horizontal and vertical direction properties of the alloy. The alloy with a Ti content of 0.112 wt% exhibits the best comprehensive properties. There is no difference in its horizontal and vertical direction properties. The tensile strengths, yield strengths, and elongation of this alloy(T6) along the vertical and horizontal axis are 356 and 355 MPa, 307 and308 MPa, and 8.5% and 8.0%, respectively.

关键词： Wire arc additive manufacturing Al–7Si–0.6Mg alloy Microstructure and properties Titanium

Fabrication and modelling of Si_(3)N_(4)ceramics with radial grain alignment generated through centripetal sinter-forging

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Journal of Materials Science & Technology 2022年第31期126卷 1-14页

作者： Da-Wang Tan zhen-Yong Lao wei-ming Guo Akira Kondo Takahiro Kozawa Makio Naito Kevin Plucknett Hua-Tay Lin Department of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China Joining and Welding Research Institute Osaka University11-1 MihogaokaIbarakiOsaka 567-0047Japan Department of Mechanical Engineering Dalhousie UniversityHalifaxNova Scotia B3H 4R2Canada

Silicon nitride(Si_(3)N_(4))based ceramics are one of the most attractive advanced engineering materials,which have been widely used under high-speed rotational operation or for mechanical contacts across a curved *** the present study,rotationally symmetric texturing of Si_(3)N_(4),with radial grain align-ment,was obtained by centripetal sinter-forging(CSF)of a partially sintered *** average values of the included angles between the c-axis of the local Si_(3)N_(4)grain and radial direction were approxi-mately 16.4°and 11.0°,on the section plane perpendicular to the pressing direction,and parallel to both the pressing and radial directions,*** compressive strain in the pressing direction forced the ceramic body to flow towards the central axis,resulting in compressive strain in the tangential di-rection and tensile strain in the radial direction.A fundamental physical model was created to simulate the grain rotation during the 3-dimentional strain reorientation,which revealed the rod-like grain would preferentially rotate toward the center of the sample under the CSF *** addition,due to the fric-tion between the sample surface and the pressing punch,the increased shear strain could enhance the Si_(3)N_(4)grain ***,ceramics with rod-like grains perpendicular to the curved side sur-face could be anticipated by applying the centripetal forming concept in a controlled manner.

关键词： Si_(3)N_(4)ceramic Texture Radial grain alignment Modeling CSF

Support vector regression-based operational effectiveness evaluation approach to reconnaissance satellite system

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1626-1644页

作者： HAN Chi XIONG wei XIONG minghui LIU zhen College of Aerospace Information Space Engineering UniversityBeijing 101400China Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering UniversityBeijing 101400China

As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and *** at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional *** the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter *** the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of *** experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global *** index system and evaluation method are constructed based on the characteristics of *** validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational *** to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.

关键词： reconnaissance satellite system(RSS) support vector regression(SVR) gray wolf optimizer opposition-based learning parameter optimization effectiveness evaluation

Effect of energy density on defect evolution in 3D printed Zr-based metallic glasses by selective laser melting

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 104-110页

作者： wei Xing Di Ouyang zhen Chen Lin Liu School of Materials Science and Engineering and State Key Lab for Materials Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074China State Key Lab for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China

In this study, the defects in 3D printed Zr-based bulk metallic glasses(BMGs) fabricated by selective laser melting(SLM) under different energy densities have been investigated via both experimental and simulation approaches. Different defects, including balling, interlayer pores, open pores and metallurgical pores, are detected in the 3D-printed Zr-based MGs depending on the energy inputs. Balling mainly occurs at a relatively low energy density(E<8.33 J/mm^3) due to the incomplete melting of particles, while interlayer pores and open pores are formed at modest energy densities(E=13.89-16.67 J/mm^3) because of incomplete welding and insufficient filling of molten liquid between layers. Fine metallurgical pores appear on the upper surface at relatively high energy densities(E=20.83-27.78 J/mm^3), which originate from gas escaping from molten pools during rapid solidification of the melt. Computational fluid dynamics(CFD) simulations are carried out to verify the experimental observations. The CFD simulations reveal that the various defects formed in the 3D-printed Zr-based BMG are related to the melt flow behaviours in the molten pools under different energy densities. The present work provides in-depth understandings of defect formation in the SLM process and provides methods for eliminating these defects in order to enhance the mechanical performance of 3D printed BMGs.

关键词： metallic glass selective laser melting defect formation mesoscopic simulation

A new meshless approach for bending analysis of thin plates with arbitrary shapes and boundary conditions

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Frontiers of Structural and Civil Engineering 2022年第1期16卷 75-85页

作者： wei DU Xiaohua ZHAO Huiming HOU zhen WANG Department of Civil and Environmental Engineering Shantou UniversityShantou 515063China Key Laboratory of Structure and Wind Tunnel of Guangdong Higher Education Institutes Shantou 515063China

An efficient and meshfree approach is proposed for the bending analysis of thin *** approach is based on the choice of a set of interior points,for each of which a basis function can be *** deflection is then approximated as the linear combination of those basis *** traditional meshless methods,present basis functions are defined in the whole domain and satisfy the governing differential equation for ***,no domain integration is needed,while the unknown coefficients of deflection expression could be determined through boundary conditions by using a collocation point *** efficiency and accuracy of the approach are shown through numerical results of plates with arbitrary shapes and boundary conditions under various loads.

关键词： plate bending meshless method collocation

Effects of Prandtl number in two-dimensional turbulent convection

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Chinese Physics B 2021年第9期30卷 290-296页

作者： Jian-Chao He ming-wei Fang zhen-Yuan Gao Shi-Di Huang Yun Bao School of Aeronautics and Astronautics Sun Yat-sen UniversityGuangzhou 510275China Center for Complex Flows and Soft Matter Research and Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Turbulence Research and Applications Southern University of Science and TechnologyShenzhen 518055China

We report a numerical study of the Prandtl-number(Pr)effects in two-dimensional turbulent Rayleigh-Bénard *** simulations were conducted in a square box over the Pr range from 0.25 to 100 and over the Rayleigh number(Ra)range from 10^(7) to 10^(10).We find that both the strength and the stability of the large-scale flow decrease with the increasing of Pr,and the flow pattern becomes plume-dominated at high *** evolution in flow pattern is quantified by the Reynolds number(Re),with the Ra and the Pr scaling exponents varying from 0.54 to 0.67 and-0.87 to-0.93,*** is further found that the non-dimensional heat flux at small Ra diverges strongly for different Pr,but their difference becomes marginal as Ra *** the thermal boundary layer,the spatially averaged thicknesses for all the Pr numbers can be described byδθ~Ra^(-0.30) approximately,but the local values vary a lot for different Pr,which become more uniform with Pr increasing.

关键词： turbulent convection Prandtl number direct numerical simulations(DNS)