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International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1618-1626页

作者： Zexun Tang Hongqi Ye Xin Ma Kai Han Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China Cathode Material Research&Development Department Soundon New Energy Technology Co.Ltd.Xiangtan 411100China

Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles.As for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electrochemical properties of the cathode.In this work,the structure,morphology,and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles and single crystals were systematically studied.A lower Ni^(2+)/Ni^(3+)molar ratio of 0.66 and a lower residual alkali content of 0.228wt%were achieved on the surface of the single crystals.In addition,the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C(~12 mAh/g lower than that of the secondary particles)and enhanced the electrochemical stability,especially when cycled at 50℃ and in a wider electrochemical window(between 3.0 and 4.4 V vs.Li+/Li).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles were suitable for applications requiring high specific capacity,whereas single crystals exhibited better stability,indicating that they are more suitable for use in long life requested devices.

关键词： Ni-rich layered materials single crystal cathode micro-structure lithium-ion battery

Research on the process of fabricating a multi-layer metal micro-structure based on UV-LIGA overlay technology

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Nanotechnology and Precision Engineering 2019年第2期2卷 83-88页

作者： Yali Ma Wenkai Liu Chong Liu Department of Military Materials Distribution Army Military Transportation UniversityTianjin 300161China School of Mechanical Engineering Dalian University of TechnologyDalian 116023China

In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve the process problems in the masking procedure,the swelling problemof the first layer of SU-8 thick photoresist was studied experimentally.The 5μmline-width compensation and closed 20μmand 30μmisolation strips were designed and fabricated around the micro-structure pattern.The pore problemin the Ni micro-electroforming layer was analyzed and the electroforming parameters were improved.The pH value of the electroforming solution should be controlled between 3.8 and 4.4 and the current density should be below 3 A/dm^2.To solve the problems of high inner stress and incomplete development of the micro-cylinder hole array with a diameter of 30μm,the lithography process was optimized.The pre-baking temperature was increased via gradient heating and rose every 5℃ from 65℃ to 85℃ and then remained at 85℃ for 50 min–1 h.In addition,the full contact exposure was used.Finally,a multi-layer metal micro-structure with high precision and good quality of microelectroforming layer was fabricated using UV-LIGA overlay technology.

关键词： UV-LIGA overlay technology SU-8 photoresist micro-electroforming technology Multi-layer metal micro-structure

NUMERICAL SIMULATION FOR CONVECTION-DIFFUSION PROBLEM WITH PERIODIC micro-structure

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Acta Mathematica Scientia 2008年第2期28卷 236-252页

作者：吴志华严宁宁 Institute of System Sciences Academy of Mathematics and System Sciences Chinese Academy of Sciences

In this article, the convection dominated convection-diffusion problems with the periodic micro-structure are discussed. A two-scale finite element scheme based on the homogenization technique for this kind of problems is provided. The error estimates between the exact solution and the approximation solution, of the homogenized equation or the two-scale finite element scheme are analyzed. It is shown that the scheme provided in this article is convergent for any fixed diffusion coefficient 5, and it may be convergent independent of δ under some conditions. The numerical results demonstrating the theoretical results are presented in this article.

关键词： Convection-diffusion problem homogenization micro-structure asymptotic expansion

EXPERIMENTAL STUDY ON MACRO AND micro-structure OF METALLIC PARTS BUILT BY LOW-POWER LASER CLADDING

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Chinese Journal of Mechanical Engineering 2005年第2期18卷 263-266页

作者： LiuJichang LiLijun LaserInstitute HunanUniversityChangsha410082China

A low-power CO_2 laser is used to deposit Fe powder and mixture of Fe andcarbon powder on substrates respectively, and the macro and micro-structure of the formed samplesare investigated. It is demonstrated that most grains of these samples are equi-axed. This isderived from the high nucleation velocity in the shallow melt pool besides rapid solidification ofthe liquid-state alloy or metal. Bainitic structure, combination of pearlite and ferrite structureand ferrite structure are seen respectively in the samples involving various amounts of carbon owingto no martensitic transformation in these small samples.

关键词： Laser cladding forming micro-structure Low-power laser

Rational designed microstructure pressure sensors with highly sensitive and wide detection range performance

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Journal of Materials Science & Technology 2022年第35期130卷 184-192页

作者： Yimeng Ni Lexin Liu Jianying Huang Shuhui Li Zhong Chen Weiying Zhang Yuekun Lai College of Chemical Engineering Fuzhou UniversityFuzhou 350116China Department of Chemistry University College LondonLondonUK School of Materials Science and Engineering Nanyang Technological University50 Nanyang AvenueSingapore

Highly sensitive pressure sensors are often deployed in human-machine interaction area,touch screen and human motion detection.However,there are still great challenges to fabricating with high sensitivity pressure sensor with wide-range detection.Herein,we developed a new strategy to fabricate a highly sensitive pressure sensor using sandpaper and improve its detection range using a sacrificial template.It was the fthatirst time to combine microstructure processing with the sacrificial template method to fabricate pressure sensor.The microstructure of sandpaper endowed the sensor with high sensitivity,and the elastic substrate enhanced the sensor ability to resist high pressure without being damaged.The fabricated sensor device exhibits a superior sensitivity of 39.077 kPa-1in the range from 50 kPa to 110 kPa with a broad linear response.Remarkably,high pressure ceiling(micro-structured elastic sponge material provided new ideas for exploring its potential applications in pressure sensors and flexible wearable electronic devices.

关键词： Pressure sensor High sensitivity Conductive sponge Template micro-structure

High-performance Multilayer Flexible Piezoresistive Pressure Sensor with Bionic Hierarchical and Anisotropic structure

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Journal of Bionic Engineering 2022年第5期19卷 1439-1448页

作者： Meng Wang Yue Yu Yunhong Liang Zhiwu Han Chunbao Liu Suqian Ma Zhaohua Lin Lei Ren The Key Laboratory of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130025China Center of Reproductive Medicine Center of Prenatal DiagnosisThe First Hospital of Jilin UniversityChangchun 130021China Department of Endocrinology and Metabolism China-Japan Union Hospital of Jilin UniversityChangchun 130033China School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130025China

Flexible pressure sensor that enables detection of multimodal signals has greater advantages in human–computer interaction,medical/health care,and other applications.To make a versatile flexible pressure sensor,hierarchical and anisotropy structure are key features to improve sensing performance and realize multi-signal detection.However,traditional flexible sensors usually have narrow linear range and single signal detection capability.Herein,a highly sensitive flexible piezoresistive pressure sensor which has broad linear range of pressure is developed by replicating one dimensional microstructures from reed leaf and using multilayer superposition of micropatterned polydimethylsiloxane(m-PDMS).Through superposing 4 layers of parallel micropatterned constructive substrates,the multilayer piezoresistive pressure sensor exhibits a high sensitivity of 2.54 kPa?1,a fast response time of 30 ms,and a broad linear range of 107 kPa.The flexible piezoresistive pressure sensor is also highly robust:there is no fatigue after testing for at least 1000 cycles.Due to the specific anisotropy of the micro-structure,the sensor can measure the tangential force in different directions.It permits multimode signal detection,including pressure,tangential force,and deformation.The versatile flexible pressure sensor enables effective monitoring of multisignals,it reveals great potential for medical and health care,flexible human–computer interaction,and intelligent robot.

关键词： Piezoresistive pressure sensor Multilayer Anisotropy micro-structure Bionic

On a Standard Parametric Modeling Method of micro-structure of Plain Woven Composite

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Journal of Textile Science and Technology 2016年第3期2卷 56-66页

作者： Shanli Wang Information Center Tianjin Polytechnic University Tianjin China

A new standard parametric modeling method of the micro-structure of plain woven composite is proposed. It is based on good analysis of the mechanical property of the yarn, weaving law of plain woven, and other factors. The method implements a woven fabric composite visual engineering modeling process standardization, and it gives five steps to calculate the key micro-structural parameters of the yarn including the cross-section and the trajectory of the central Line. On the basis, the digital model of a plain woven composite has been constructed. The experimental result shows that the forecast for the mechanical property of the model using finite-element simulation analysis is consistent with the actual value. The shape and the structure of the model are also consistent with the solid.

关键词： Plain Woven Composite micro-structure Parametric Modeling Standardization Process

The Effect of micro-structure on Fatigue Behaviour of Intact Sandstone

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International Journal of Geosciences 2011年第3期2卷 240-247页

作者： Manoj N.Bagde Vladimir Petros Central Institute of Mining and Fuel Research Regional CentreMECL ComplexNagpurIndia Faculty of Mining and Geology VSB-TUOstravaCzech Republic

With advent of servo-controlled stiff testing machines, it is now possible to conduct tests on a rock in the laboratory under different variable controlled conditions. In this paper, cyclic fatigue behaviour of intact sandstone obtained from the rock burst prone coal mine in the Czech Republic were presented. Tests were conducted on MTS- 816 rock test system in the laboratory on intact rock samples of L/D ratio 2 under cyclic loading frequency of 0.1, 1, 3, 5, 7 and 10 Hz at amplitude of 0.1 mm under displacement control mode until failure of the samples in uni-axial compression. From, the primary results it was observed that at low loading frequency range of 0.1 to 3 Hz, there was degradation of the rock samples in terms of fatigue strength and modulus. While, at higher frequency rose-up in strength and deformation properties were observed. It was observed that the machine behaviour in terms of amplitude at higher loading frequencies might be affecting the results. It seemed that machine behaviour of servo-hydraulic testing system was also dependent on rock type under investigation.

关键词： Cyclic Loading Fatigue micro-structure Machine Behaviour Rock Memory

Superposition of orbital angular momentum of photons by a combined computer-generated hologram fabricated in silica glass with femtosecond laser pulses

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Chinese Physics B 2008年第11期17卷 4199-4203页

作者：郭忠义曲士良孙正和刘树田 Department of Physics Harbin Institute of Technology Department of Optoelectronic Science Harbin Institute of Technology at Weihai

This paper introduces a novel method to realize the superposition of orbital angular momentum of photons by combined computer-generated hologram （CCGH） fabricated in silica glass with femtosecond laser pulses. Firstly, the two computer-generated holograms （CGH） of optical vortex were obtained and combined as a CCGH according to the design. Then the CCGH was directly written inside glass by femtosecond laser pulses induced microexplosion without any preor post-treatment of the material. The vortex beams with different vortex topological charges （including new topological charges） have been restructured using a collimated He-Ne laser beam incidence to the CCGH normally. A theoretical and experimental explanation has been presented for the generations of the new topological charges.

关键词： femtosecond laser micro-structure optical vortices CGH

Numerical simulation of thermo-mechanical fatigue properties for particulate reinforced composites

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Acta Mechanica Sinica 2005年第2期21卷 160-168页

作者： RanGuo HuijiShi ZhenhanYao DepartmentofEngineeringMechanics FML.TsinghuaUniversityBeijing100084China

In this paper, a two dimensional Voronoi cell element, formulated with creep, thermal and plastic strain, is applied for the numerical simulation of thermo-mechanical fatigue behavior for particulate reinforced composites. The relation between mechanical fatigue phases and thermal fatigue phases influences the thermo-mechanical fatigue behavior and cyclic creep damage. The topological features of micro-structure in particulate reinforced composites, such as the orientation, depth-width ratio, distribution and volume fraction of inclusions, have a great influence on thermo-mechanical behavior. Some related conclusions are obtained by examples of numerical simulation.

关键词： Particulate reinforced composites Thermo-mechanical fatigue property Numerical simulation Voronoi cell finite element micro-structure