检索结果-南通市图书馆

Built-in electric field induced S-scheme g-C_(3)N_(4)homojunction for efficient photocatalytic hydrogen evolution:Interfacial engineering and morphology control

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 4961-4970页

作者： Yongpan gu Yike Li Haoqiang Feng Yanan han Zhongjun Li College of Chemistry Zhengzhou UniversityZhengzhou 450001China

S-scheme possesses superior redox capabilities compared with the II-scheme,providing an effective method to solve the innate defects of g-C_(3)N_(4)(CN).In this study,S-doped g-C_(3)N_(4)/g-C_(3)N_(4)(SCN-tm/CN)S-scheme homojunction was constructed by rationally integrating morphology control with interfacial engineering to enhance the photocatalytic hydrogen evolution ***-situ Kelvin probe force microscopy(KPFM)confirms the transport of photo-generated electrons from CN to *** functional theory(DFT)calculations reveal that the generation of a built-in electric field between SCN and CN enables the carrier separation to be more efficient and *** transient absorption spectrum(fs-TAS)indicates prolonged lifetimes of SCN-tm/CN_(3)(τ1:9.7,τ2:110,andτ3:1343.5 ps)in comparison to those of CN(τ1:4.86,τ2:55.2,andτ3:927 ps),signifying that the construction of homojunction promotes the separation and transport of electron hole pairs,thus favoring the photocatalytic *** visible light irradiation,the optimized SCN-tm/CN_(3)exhibits excellent photocatalytic activity with the hydrogen evolution rate of 5407.3μmol·g^(−1)·h^(−1),which is 20.4 times higher than that of CN(265.7μmol·g^(−1)·h^(−1)).Moreover,the homojunction also displays an apparent quantum efficiency of 26.8%at 435 nm as well as ultra-long and ultra-stable cycle *** work offers a new strategy to construct highly efficient photocatalysts based on the metal-free conjugated polymeric CN for realizing solar energy conversion.

关键词： homojunction built-in electric field morphology control interfacial engineering carrier separation

Hybrid tri-memristor hyperchaotic map and application in Wasserstein Generative Adversarial Nets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第6期67卷 1855-1865页

作者： gu Yang BAO han YU XiHong HUA ZhongYun BAO BoCheng XU Quan School of Microelectronics and Control Engineering Changzhou UniversityChangzhou213159China School of Computer Science and Technology Harbin Institute of TechnologyShenzhen518055China

Inspired by basic circuit connection methods,memristors can also be utilized in the construction of complex discrete chaotic *** investigate the dynamical effects of hybrid memristors,we propose two hybrid tri-memristor hyperchaotic(HTMH)mapping structures based on the hybrid parallel/cascade and cascade/parallel operations,*** the HTMH mapping structure with hybrid parallel/cascade operation as an example,this map possesses a spatial invariant set whose stability is closely related to the initial states of the *** distributions and bifurcation behaviours dependent on the control parameters are explored with numerical ***,the memristor initial offset-boosting mechanism is theoretically demonstrated,and memristor initial offset-boosting behaviours are numerically *** results clarify that the HTMH map can exhibit hyperchaotic behaviours and extreme multistability with homogeneous coexisting infinite *** addition,an FPGA hardware platform is fabricated to implement the HTMH map and generate pseudorandom numbers(PRNs)with high ***,the generated PRNs can be applied in Wasserstein generative adversarial nets(WGANs)to enhance training stability and generation capability.

关键词： memristor hybrid tri-memristor map spatial invariant set hyperchaos extreme multistability generative adversarial nets

Investigation of the Film Formation in Dynamic Air Spray Painting

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第10期20卷 2393-2415页

作者： Deqing han Yong Zeng Jintong gu Bin Yan School of Mechanical Engineering Yancheng Institute of TechnologyYancheng224051China

To accurately predict the film thickness distribution during dynamic spraying performed with air guns and support accordingly the development of intelligent spray painting,the spray problem was analyzed *** particular,the Eulerian-Eulerian approach was employed to calculate the paint atomization and film deposition *** spray heights,spray angles,spray gun movement speeds,spray trajectory curvature radii,and air pressure values were *** simulation results indicate that the angle of spray painting significantly affects the velocity of droplets near the spray *** an increase in the spraying angle,spraying height and spray gun movement speed,the maximum film thickness decreases to varying degrees,and the uniformity of the film thickness also continuously *** the spray gun moves along an arc trajectory,at smaller arc radii,the film thickness on the inside of the arc is slightly greater than that on the outside,but the impact on the maximum film thickness is *** air pressure expands the coating coverage area,results in finer atomization of paint droplets,and leads to a thinner and a more uniform paint ***,if the pressure is too high,it can cause paint *** the orthogonal experimental method,multiple sets of simulation calculations were conducted,and the combined effects of spraying height,spray angle,and spray gun movement speed on the film thickness distribution were comprehensively analyzed to determine optimal ***,the reliability of the numerical simulations was validated through dynamic spray painting experiments.

关键词： Air spray painting CFD simulation paint film-forming regularity orthogonal array testing

Dynamic synthetic analysis of circulation field of tropical cyclones affecting Shanghai

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2024年第2期18卷 347-363页

作者： Wen gu Caijun YUE Zhihui han Yanqing GAO Yuqi TANG Xiangyu AO Yao YAO Shanghai Ecological Forecasting&Remote Sensing Center Shanghai 200030China Shanghai Marine Meteorological Centre Shanghai 200030China Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China Key Laboratory of Numerical Modeling for Tropical Cyclone(China Meteorological Administration) Shanghai 200030China

Eleven tropical cyclones(TCs)affected Shanghai and crossed the same latitude as Shanghai from 2007 to *** to similar tracks from best-track data,TCs that cause significant precipitation in Shanghai can be divided into three types:landfall TCs,nearshore northward TCs,and western *** on ERA5 reanalysis data,the dynamic synthesis method was used to synthesize TC circulation situations to compare thermal,dynamic,water vapor,and stability conditions within TC circulations during the period when they affected *** conclusions are as follows.1)When the three TC types are at the same latitude as Shanghai,they are all in the divergent field in the upper *** the landfall type,the subtropical high at 500 hPa is stronger and farther north than usual,and there is a high-pressure dam on the north side of the TCs.2)The warm advection of the three TC types at 925 hPa is located in the northern quadrant of the *** dynamic and water vapor conditions are good in the north-western quadrant of landfall and western TCs,and more favorable in the eastern quadrant of nearshore northward TCs.3)The favorable effects of all three types on precipitation in Shanghai come from the boundary *** vapor,upward motion,and instability conditions of landfall TCs are superior to the other two TC *** best water vapor,dynamic,and convective instability conditions are at the northern boundary in Shanghai during landfall TCs,and the main sources of water vapor in Shanghai come from the eastern and northern *** nearshore northward TCs,the main contribution to precipitation is from the eastern boundary,while better dynamic and water vapor conditions come from the western and northern boundaries during western *** above findings provide scientific and technical support for operational forecasting precipitation from TCs affecting mega-cities.

关键词： tropical cyclones dynamic synthetic analysis ERA5 reanalysis Shanghai similar track

An improved elastoplastic model for rocks and application to cyclic loading and unloading triaxial compression tests

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第8期40卷 179-193页

作者： Qiuxin gu Qiang Zhang Yapeng Li Peinan Wu guilei han State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou221116China North China Engineering Investigation Institute Shijiazhuang050021China

The recoverable strain of rock is completely classified as elastic strain in the conventional elastic-plastic theory,which often results in poor agreement between theoretical and experimental *** work proposes an improved elastoplastic model of rock materials considering the evolutions of crack deformation and elastic modulus to better characterize the nonlinear mechanical behavior of rock in the post-peak *** this model,the recoverable strain is assumed to be a combination of elastic and crack strain,and the constitutive relationship between crack strain and rock stress is *** on the proposed assumption,the evolutions of the mechanical parameters including strength parameters,elastic,plastic,and crack deformation parameters versus the plastic strain and confining stress were *** developed elastoplastic model was validated by comparing the theoretical values with the results of the triaxial cyclic loading and unloading *** theoretical calculation results show a good agreement with the laboratory test,which indicates that the improved elastoplastic model can effectively reflect the nonlinear mechanical behavior of the rock *** research results are expected to provide a valuable reference for further understanding the evolution of rock crack deformation.

关键词： Crack strain Elastic modulus deterioration Novel elastoplastic model Model validation

A reverse particle grading strategy for design and fabrication of porous SiC ceramic supports with improved strength

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第7期13卷 1011-1022页

作者： Zheng Liang han Zhang Yichuan Li Wenkang Zhang Jian Zhou Qilin gu Zhaoxiang Zhong Weihong Xing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneNanjing Tech UniversityNanjing 211816China Nanjing Membrane Application Institute Co. Ltd.Nanjing 210009China

Porous ceramics usually require high mechanical strength and maximized porosity simultaneously,while for conventional particle grading strategies,it is highly challenging to meet both *** this end,a reverse particle grading strategy was developed based on the linear packing model by unusually introducing coarse particles(d_(50)=16μm)into a fine particle(d50=5μm)*** the extrusion and sintering process,tubular porous SiC ceramic supports with improved mechanical strength were successfully *** effects of coarse particles on the rheological properties of the ceramic paste and the macroscopic properties and microstructure of the SiC supports were systematically *** an increase in the content of coarse SiC particles to 30 wt%,the pressure generated during extrusion decreased from 5.5±0.2 to 1.3±0.1 ***,the bending strength of the tubular supports increased from 36.6±5.6 to 49.1±4.5 MPa when 20 wt%coarse powder was *** notably improved mechanical strength was attributed to the distribution of coarse particles that prolonged the route of crack ***,the optimized tubular supports had an average pore size of 1.2±0.1μm,an open porosity of 45.1%±1.6%,and a water permeability of 7163±150 L/(m^(2)·h·bar)as well as good alkali and acid corrosion ***,the strategy was proven to be feasible for the scale-up fabrication of 19-channel SiC tubular porous ceramic supports.

关键词： porous SiC ceramic tubular ceramic support reverse particle grading reaction bonding chemical stability

Additive manufacturing of NiTi lightweight porous structures bio-mimicking coral skeleton with enhanced mechanical properties and shape memory functions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第8期67卷 2461-2474页

作者： LIU Xin gu DongDong YUAN LuHao ZhanG han SUN JianFeng CHEN WenXin WANG Jie SHI KeYu Jiangsu Provincial Research Center for Laser Additive Manufacturing of High-Performance Components College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

Concerning the high demand for lightweight and multifunctional properties of engineering structures, the coral skeleton-inspired sheet-based(CSS) structure, which was a novel bio-mimicking coral skeleton wall-septa architecture with a unique ability to resist wave shocks was fabricated using NiTi alloy by laser powder bed fusion(LPBF) technology. The effects of laser energy density(LED) on surface morphologies, microstructures, phase transformation behavior, and mechanical properties of LPBFfabricated CSS structures were systematically investigated. The results indicated that the size deviation was predominantly governed by powder adhesion and step effect. NiTi CSS structures with LED of 71 J·mm~(-3)possessed superior compressive modulus(~400 MPa), ultimate strength(~13 MPa), and energy absorption efficiency(~69%). The compression fracture mechanism of the LPBF-fabricated NiTi CSS structures was revealed to be predominantly brittle fracture accompanied by ductile fracture. Furthermore, the Ni_4Ti_3 nanoprecipitates induced the precipitation strengthening effect, enabling better shape memory response at LED of 71 J·mm~(-3), with a recoverable strain of 3.63% and recovery ratio of 90.8%, after heating under a pre-strain of 4%. This study highlights the importance of a bionic design strategy for enhancing the mechanical properties of NiTi components and offers the possibility to tailor its functional properties.

关键词： bioinspired structures laser powder bed fusion NiTi shape memory alloy mechanical performance

同方期刊数据库

Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2935-2946页

作者： Jie Liu Bin Shi Kai gu Meng-Ya Sun Jun-Cheng Yao He-Ming han School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing210023China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China

Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial *** the subsurface evolution characteristics of the artificial land is essential,yet ***,we use an improved fiber-optic monitoring system for its subsurface multi-physical *** system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and ***’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long *** reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact ***,the filling loess exhibits a stronger creep capability compared to underlying intact *** deformation along the profile is unevenly distributed,with a positive correlation with soil *** accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant ***,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,*** refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.

关键词： Mountain excavation and city construction Fiber-optic monitoring Multi-physical characterization Compacted loess

Cement-inspired readily fabricated water-strengthened polymeric materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第10期67卷 3458-3467页

作者： han Zuo Luzhi Zhang Huixia Xuan Shijia gu Xinxin Xu Rasoul Esmaeely Neisiany Qilin Wu Zhengwei You State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsCollege of Materials Science and EngineeringDonghua UniversityResearch Base of Textile Materials for Flexible Electronics and Biomedical Applications(China Textile Engineering Society)Shanghai Key Laboratory of Lightweight CompositeShanghai Engineering Research Center of Nano-Biomaterials and Regenerative MedicineShanghai 201620China Zhejiang Hexin Science and Technology Co. Ltd.Jiaxing 314033China Biotechnology Centre Silesian University of TechnologyKrzywoustego 844-100 GliwicePoland Department of Polymer Engineering Hakim Sabzevari UniversitySabzevar ***Iran

Polymeric materials have penetrated all aspects of society and play an irreplaceable ***,there is an inherent contradiction between their mechanical properties and processing ***,inspired by cement,a crucial construction material renowned for its excellent fabricating behavior and self-strengthening properties,we have developed dynamic crosslinked poly(oxime-urethane)(CPOU).The synthesized CPOU showed good self-healing ability and 3D printability owing to the dynamic dissociation and re-association of oxime-carbamate *** objects printed through the fused deposition modeling technique were able to be readily assembled into complex architectures through intrinsic ***,the self-strengthening of CPOU was successfully realized through multiple-step tandem *** dissociation of dynamic oxime-carbamate bonds produced–NCO groups,which reacted with the surrounding water to form polar urea bonds in the polymer network,leading to an increase in the tensile strength of CPOU from 11.95 to 19.37 *** work not only develops the polymers with combined self-healing,facile fabricating,and self-strengthening properties but also provides a new molecular strategy to modulate the properties of polymers,which could be potentially applied in diverse areas.

关键词： dynamic bonds 3D printing self-strengthening self-healing