检索结果-南通市图书馆

Journal of Materials Science & Technology 2022年第35期130卷 86-92页

作者： Xinran Ma Yuping Duan Lingxi Huang Ben Ma Hao Lei key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116085China

In the electronic information and intelligent era, microwave absorption materials have been focused on the issue of electromagnetic(EM) pollution, but high-performance absorbers with thin thickness are highly desirable. The positive action between structural design and component selection can be regarded as a function to optimize the microwave loss capacity, which contributes to understanding the response mechanisms from the micro and macro. Therefore, we designed the absorber with quasiperiodic structures of Penrose tiling that has finely engineered the location of maximum absorption peak, the spherical carbonyl iron in thin rhombus, and flakey carbonyl iron in fat rhombus, the effective absorption bandwidth(Reflection Loss ≤ –10 d B) was realized from 6.46 GHz to 15.78 GHz in the 2 mm thickness. The unique arrangement of Penrose tiling can respond alternatingly to EM waves at large scales, and multicomponent coupling is distinctly in the neighboring unit cells. In addition, spraying aluminum pigment as the upper layer, the infrared emissivity is less than 0.35 to meet the complex application *** work opens up novel ideas on quasiperiodic structure combined multicomponent and injects infinite vitality to provide prospects for broadband responsive and high-efciency EM absorbers.

关键词： Microwave absorber Penrose tiling Carbonyl iron Localized coupling

Transformation between nanosheets and nanowires structure in MnO2 upon providing Co^2+ions and applications for microwave absorption

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第1期13卷 95-104页

作者： Lulu Song Yuping Duan Jia Liu Huifang Pang key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian116085China

The phase transition process of the MnO2 phase with increases in Co^2+doping can be described by the Ouroboros *** undoped sample is pureδ-MnO2 with nanosheets *** a small amount of Co^2+ions changes the final products and generatesα-MnO2 nanofibres in theδ-MnO2 *** products become pureα-MnO2 with an appropriate amount of Co ***,when the Co amount continues to increase,the amount ofα-MnO2 decreases in the products and turns back to form pureδ-MnO2 in the *** the electromagnetic absorption performance,the relationship between the properties and the proportion ofδ-MnO2/α-MnO2 in the powders adjusted by Co^2+doping has been explored,and the composites ofδ-/α-MnO2 show better absorption ability than the single-phase *** a result,the optimal reflection loss(RL)is−54.8 dB,and the effective absorption bandwidth can cover the Ku band at a thickness of 2.2 mm and the X band at a thickness of 3.1 mm with 50 wt.%filler loading *** research might shed new light on the improvement of novel microwave absorption materials.

关键词： phase transitions self-assembly impedance matching microwave absorption

Dual-polarized and real-time reconfigurable metasurface absorber with infrared-coded remote-control system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2022年第8期15卷 7498-7505页

作者： Jiangyong Liu Yuping Duan Tuo Zhang Lingxi Huang Huifang Pang key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116085China

The reconfigurable metasurfaces which can regulate the microwave absorption performance at the sub wavelength scale provide a possibility to construct intelligent stealth ***,the existing reconfigurable-metasurface-based absorbers seriously limit the medium and long-distance regulation in practical application due to the complex circuit path and regulation ***,an infrared-coded dual-polarized metasurface absorber(IDMA)with remote-control mode was proposed,which realized the realtime dynamic regulation of the intensity and frequency range of absorption peaks by combining the infrared-coding remotecontrol technology with the active metasurface *** proposed remote-control system can switch the 8-bit binary coding sequences stored in the microcontroller unit(MCU)by an infrared transceiver,so as to regulate the state of active devices under X-and Y-polarizations,*** experimental results showed that the reflection/absorption responses can be regulated by switching different binary codes,and the reflection loss(RL)can be tuned below−7.5 dB(absorptivity over 82%)in wide range of 6.20–18 ***,the corresponding equivalent circuit model was established and the distributions of surface current and electric field were analyzed to elucidate the dynamic reconfigurable mechanism of the metasurface *** proposed IDMA,which combines intelligent electronic technology with active metasurface absorber,creatively realizes the remote control of active metasurface absorber and opens up a new way for the stealth technology of smart absorber in the future.

关键词： microwave absorption active metasurface reflection/absorption infrared-coded remote-control real-time dynamic control

On-Line Measurement Method for Diameter and Roundness Error of Balls

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nanomanufacturing and Metrology 2020年第3期3卷 218-227页

作者： Yindi Cai Bo Xie Siying Ling Kuang-Chao Fan key laboratory for Micro/Nano Technology and System of liaoning province Dalian University of TechnologyDalian 116024China

This paper presents an on-line measurement method for the diameter and roundness error of *** easy-installation rotary scanning system,which integrates the principles of the diameter and the roundness measurements,is *** rotary scanning system consists of a rotary stage,a linear stage,and two sensors with a什at *** sensors are initially installed on the linear stage and contact each *** outputs of two sensors are reset to zero at *** ball is then mounted on the rotary stage and positioned between two flat *** variations of the diameter and the roundness error of the ball at each angular position can be directly recorded by two sensors when the ball is rotated by the rotary *** the outputs of two sensors into the proposed mathematical models,the diameter and roundness error can be *** effects of the alignment error induced by the spindle error of the rotary stage and the titling error and the eccentric error of the ball on the measurement accuracy can be self-separated in the proposed on-line measurement method.A series of experiments are carried out to verify the effectiveness and the capability of the proposed on-line measurement method and the designed rotary scanning *** designed system is easy to construct both in the laboratory environment and the factory field.

关键词： On-line measurement Diameter Roundness error Alignment error

Bioaccumulation of heavy metals by Phragmites australis cultivated in synthesized substrates

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 Environmental Sciences 2009年第10期21卷 1409-1414页

作者： WANG He JIA Yongfeng liaoning province key laboratory of Basin Pollution Control Liaoning Academy of Environmental Sciences Shengyang 110031 China. Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China.

Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order： Al（OH）3 〉 Al2O3 〉 Fe3O4 〉 MnO2 〉 FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.

关键词： heavy metals bioaccumulation metal oxides adsorption

Synthesis of Cu-Doped Mixed-Phase TiO_2 with the Assistance of Ionic Liquid by Atmospheric-Pressure Cold Plasma

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2016年第5期18卷 494-499页

作者：詹志彬底兰波张秀玲李燕春 College of Physical Science and Technology Dalian University key laboratory for Non-traditional & Functional Materials Preparation of Education Department of liaoning province Dalian University

An atmospheric-pressure dielectric barrier discharge （DBD） gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid （IL） and using air as the working gas. The influences of the discharge voltage, IL and the amount of copper nitrite were investigated. X-ray diffraction, N2 adsorption-desorption measurements and UV-Vis spectroscopy were adopted to characterize the samples. The results showed that the specific surface area of TiO2 was promoted with Cu-doping （from 57.6 m^2.g^-1 to 106.2 m^2.g^-1 with 3% Cu-doping）, and the content of anatase was increased. Besides, the band gap energy of TiO~ with Cu-doping decreased according to the UV-Vis spec- troscopy test. The 3%Cu-IL-TiO2 samples showed the highest eificiency in degrading methylene blue （MB） dye solutions under simulated sunlight with an apparent rate constant of 0.0223 min-1, which was 1.2 times higher than that of non-doped samples. According to the characterization results, the reasons for the high photocatalytic activity were discussed.

关键词： dielectric barrier discharge (DBD) gas-liquid cold plasma atmospheric pres-sure mixed-phase Ti02 Cu-doped

Asymmetric electric field distribution enhanced hierarchical metamaterials for radar-infrared compatible camouflage

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第15期146卷 10-18页

作者： Tuo Zhang Yuping Duan Jiangyong Liu Hao Lei Jingxuan Sun Huifang Pang Lingxi Huang key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116085China

Metamaterials are widely used in electromagnetic radiation and camouflage for their flexible wavefront manipulation and polarization over a broad spectrum ranging from microwaves to ***,multispectral compatible camouflage faces significant challenges due to tremendous scale differences of unit cells and desired radiative properties in various spectral *** study assembles a micron-scale infrared emitter,a millimeter-scale microwave absorber,and a metal reflector to propose a hierarchical metamaterial that reduces microwave scattering and reflects low-infrared *** a proof of concept,laser etching micro-manufactures an upper infrared shielding layer with a periodic metal *** the same time,bottom square frustum metastructure composites are fabricated and optimized based on genetic *** the normal incidence transverse electromagnetic wave with a 90°azimuth angle,the hierarchical strategy and infrared unit create an asymmetric electric field distribution of local near-field coupling,which is conducive to generating additional resonance for broadening the absorption *** verify the multispectral camouflage,which shows a high absorption efficiency of more than 90%,ranging from 3.6 to 6.2 and from 8.4 to 18 GHz with a total thickness of 4.05 mm(0.049λmax).Due to the non-reflection of surrounding thermal signals in the infrared 2-22μm region,low-infrared emissivity(0.29)metamaterials can adapt to various thermal *** methodology can provide a novel route for fabricating multispectral camouflage devices.

关键词： Hierarchical metamaterials Radar-infrared compatible stealth Genetic algorithm Magnetic-dielectric lossy composites Asymmetry

Effect of Nb doping on microstructures and thermoelectric properties of SrTiO_3 ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第4期27卷 90-95页

作者： Da-Quan Liu Yu-Wei Zhang Hui-Jun Kang Jin-Ling Li Xiong Yang Tong-Min Wang key laboratory of Solidification Control and Digital Preparation Technology （liaoning province） School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

Nb-doped SrTiO3 thermoelectric ceramics with different niobium concentrations,sintering temperatures and Sr-site vacancies are successfully prepared by high energy ball milling combined with carbon burial *** fully understanding the effect of niobium doping on SrTiO3,thermoelectric transport properties are systematically investigated in a temperature range from 300 K to 1100 *** carrier mobility can be significantly enhanced,and the electrical conductivity is quadrupled,when the sintering temperature rises from 1673 K to 1773 K（beyond the eutectic temperature（1713 K） of SrTiO3–TiO2）.The lattice vibration can be suppressed by the lattice distortion introduced by the doped niobium ***,Sr-site vacancies compensate for the lattice distortion and increase the lattice thermal conductivity more or ***,we achieve a maximum value of figure-of-merit z T of 0.21 at 1100 K for Sr Ti（0.9）Nb（0.1）O3 ceramic sintered at1773 K.

关键词： thermoelectric materials SrTiO3 Nb-doped sintering temperature

A novel as-cast precipitation-strengthened Al_(0.5)V_(0.1)FeCrMnNi_(0.9) high-entropy alloy with high strength and plasticity

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第9期64卷 1920-1926页

作者： LI ChunHui WANG MingLiang ZHANG HuanZhi ZHANG GuoJia LI TianXin LU YiPing LI TingJu key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China

A novel Al_(0.5)V_(0.1)FeCrMnNi_(0.9) high-entropy alloy was designed to achieve enhanced strength and plasticity. The as-cast Al_(0.5)V_(0.1)FeCrMnNi_(0.9) alloy shows a typical dendritic microstructure consisting of a body-centered cubic-structured matrix phase and a B2-structured nanoprecipitate phase. Nanoprecipitates are homogeneous and dispersed in the matrix. The as-cast Al_(0.5)V_(0.1)FeCrMnNi_(0.9) alloy exhibits a compressive yield strength of 1.104 GPa, a fracture strength of 2.926 GPa, and a fracture strain of 45.7%. The product of strength and plasticity of this alloy is 133.72 GPa%, which is superior to that of most of the reported high-entropy alloys. The strengthening mechanisms were evaluated in detail, which indicates that the coherent precipitation enhancement contributes to the unusually high strength and plasticity.

关键词： high-entropy alloy microstructure mechanical properties precipitation strengthening

The electromagnetic response of composition-regulated honeycomb structural materials used for broadband microwave absorption

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第29期88卷 203-214页

作者： Huifang Pang Yuping Duan Xuhao Dai Lingxi Huang Xuan Yang Tuo Zhang Xiaoji Liu key laboratory of Solidification Control and Digital Preparation Technology(liaoning province) School of Materials Science and EngineeringDalian University of TechnologyDalian116085China

The undesirable absorption bandwidth is the main limitation for the application of microwave absorbing *** that the design of structure and composition of absorbing coating allows it to obtain a satisfying absorption bandwidth and to avoid weight increasing,honeycomb and its sandwich structures coated by various absorbant have been developed and measured using an arch measurement system over2-18 *** further understand the absorption mechanisms of honeycomb structural materials,simulation based on finite element method and transmission line theory is performed to analyze the different responses to the applied microwave between honeycomb structural materials and uniform-medium slab *** proper composition design allows control over the microwave loss mechanisms,which optimize the coating to possess both of the dielectric and magnetic *** the honeycomb structural materials,the magnetic resonation is found for the first time,which is resulting from the periodic honeycomb walls on both sides of the dielectric cavity(consisting of the aramid paper interlayer and vacuum hexagonal prisms).In addition,the conversion of structure from solid to honeycomb brings about changes in impedance,propagating path,effective wavelength,effective attenuation area,microwave phases,and inductive coupling effect,etc.,which result in a better microwave absorbing *** honeycomb sandwich structure coated by CIP/CB/EP with the weight ratio of 4:0.03:1 shows the absorption bandwidth of~9.8 GHz for reflection loss(RL)lower than-10 dB which covers part of the S and C bands and almost the whole X and Ku bands.

关键词： Microwave absorption Structural materials Honeycomb Electromagnetic response