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Journal of Materials Science & Technology 2023年第3期134卷 60-66页

作者： x.S.Liu R.Li x.f.fan Q.Q.Liu x.Tong A.x.Li S.xu H.Yang S.B.Yu M.H.Jiang C.Huo P.f.Yu M.T.Dove G.Li State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China College of Computer Science Sichuan UniversityChengdu 610065China School of Physical and Chemical Sciences Queen Mary University of LondonMile End RoadLondon E14NSUnited Kingdom School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Precipitation strengthening provides one of the most widely-used mechanisms for strengthen-ing multi-principal-element alloys(MPEAs).Here,we report dual-morphology B2 precipitates in Co_(36)Cr_(15)fe_(18)Ni_(18)Al_(8)Ti_(4)Mo_(1)MPEA obtained by thermo-mechanical *** microscopy charac-terization reveals that the dual-morphology B2 precipitates are either recrystallized B2 particles formed at the grain boundaries or triple junctions with recrystallization process,or rod-like within the non-recrystallized fCC *** dual-morphology B2 precipitates enhance the yield strength and ultimate tensile strength up to 1120 MPa and 1480 MPa,*** work suggests the mechanical proper-ties of the alloy can be optimized by B2 precipitation strengthening to meet the needs of engineering applications.

关键词： Multi-principal element alloys B2 precipitates Heterogeneous nucleation Precipitation strengthening

Endoscopy-assisted lightweight diagnosis system based on transformers for colon polyp detection

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Optoelectronics Letters 2025年第1期21卷 57-64页

作者： fan Weiming YU Jiahui JU Zhaojie School of Automation and Electrical Engineering Shenyang Ligong University Department of Biomedical Engineering Zhejiang University School of Computing University of Portsmouth

The integration of endoscopy has significantly propelled the diagnosis and treatment of gastrointestinal diseases, with colonoscopy establishing itself as the primary method for early diagnosis and preventive care in colorectal cancer(CRC). Although deep learning holds promise in mitigating missed polyp rates, modern endoscopy examinations pose additional challenges, such as image blurring and atomizing. This study explores lightweight yet powerful attention mechanisms, introducing the spatial-channel transformer(SCT), an innovative approach that leverages spatial channel relationships for attention weight calculation. The method utilizes rotation operations for inter-dimensional dependencies, followed by residual transformation, encoding inter-channel and spatial information with minimal computational overhead. Extensive experiments on the CVC-Clinic DB polyp detection dataset, addressing endoscopy pitfalls, underscore the superiority of our SCT over other state-of-the-art methods. The proposed model maintains high performance, even in challenging scenarios.

关键词： Endoscopy

Rational modulation of fluorophosphate cathode by anionic groups to reduce the polarization behavior for fast-charging sodium-ion batteries

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Journal of Energy Chemistry 2025年第1期100卷 509-521页

作者： xinyuan Wang fan Zhang xingyu Zhou Qian Wang Changyu Liu Yangyang Liu Hui Wang xiaojie Liu Key Laboratory of Synthetic and Natural functional Molecule of the Ministry of Education College of Chemistry & Materials Science Northwest University

Na3V2（PO4）2O2f （VP） is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific *** functional theory （DfT） and finite element simulations show that incorporating SO42-into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge ***,the average Na+diffusion coefficient of Na3V2（PO4）1.95（SO4）0.05O2f（VPS-1） is roughly double that of VP,leading to enhanced rate capability (80 C,75.5 mAh g-1) and cycling stability (111.0 mAh g-1capacity after 1000 cycles at 10 C current density) for ***-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 *** assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current,maintaining an average coulombic efficiency of 95.35%.

关键词： Anionic group modulation Polarization behavior fast-charging Sodium-ion battery fluorophosphate Cathode

Remarkably high fracture toughness of HfNbTaTiZr refractory high-entropy alloy

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Journal of Materials Science & Technology 2022年第28期123卷 70-77页

作者： x.J.fan R.T.Qu Z.f.Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215132China

High-entropy alloys(HEAs)with face-centered cubic(fCC)phase such as CoCrfeMnNi or CoCrNi generally exhibit ultra-high fracture toughness but relatively low *** contrast,body-centered cubic(BCC)HEAs often display higher strengths,but the few reports on fracture toughness measurement demonstrate low toughness *** we show that the BCC HfNbTaTiZr refractory HEA,which possesses a combination of high strength,good tensile ductility and excellent high-temperature properties,also exhibits a remarkably high fracture *** using the"single specimen"compliance method for J-integral measurement according to the ASTM E1820–17 standard,its fracture toughness K_(JIC)was experimentally determined to be 210 MPa m^(1/2),which renders this HEA among the toughest metallic *** excellent damage tolerance makes the HEA promising for applications as high-temperature structural materials such as in aerospace field.

关键词： High-entropy alloys BCC structure fracture toughness J-integral

CO_2 adsorption using TiO_2 composite polymeric membranes:A kinetic study

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Journal of Environmental Sciences 2015年第9期27卷 163-171页

作者： Sarah Hafeez x.fan Arshad Hussain C.f.Martín School of Chemical and Materials Engineering (SCME) National University of Sciences & Technology Institute for Materials and Processes School of Engineering University of Edinburgh University of Aberdeen School of Engineering Fraser Noble Building King's College

CO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO2. Membrane gas separation is a fast growing CO2 capture technique, particularly gas separation by composite membranes. The separation of CO2 by a membrane is not just a process to physically sieve out of CO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO2 through membranes. Pure cellulose acetate（CA） and cellulose acetatetitania nanoparticle（CA-TiO2） composite membranes were fabricated and characterised using SEM and fTIR analysis. The results indicated that the blended CA-TiO2 membrane adsorbed more quantity of CO2 gas as compared to pure CA membrane. The high CO2 adsorption capacity may enhance the diffusion and solubility of CO2 in the CA-TiO2 composite membrane, which results in a better CO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion *** to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.

关键词： Global warming Cellulose acetate Gas adsorption Pseudo order models CO2 Ti O2

Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： L.f.fan Q.H.Yang x.L.Du The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

Morphology Control and Optical Absorption Properties of Ag Nanoparticles by Ion Implantation

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Journal of Materials Science & Technology 2009年第5期25卷 669-672页

作者： G.x. Cai f. Ren x.H. xiao L.x. fan x.D. Zhou C.Z. Jiang Key Laboratory of Acoustic and Photonie Materials and Devices of Ministry of Education Wuhan University Wuhan 430072 China

Ion implantation is a powerful method for fabricating nanoparticles in dielectric. for the actual application of nanoparticle composites, a careful control of nanoparticles has to be achieved. In this letter, the size, distribution and morphology of Ag nanoparticles are controlled by controlling the ion current density, ion implantation sequence and ion irradiation dose. Single layer Ag nanoparticles are formed by Ag^＋ ion implantation at current density of 2.5 μ^A/cm2. By Ag and Cu ions sequential implantation, the size of single layer Ag nanoparticles increases. While, by Cu and Ag ions sequential implantation, uniform Ag nanoparticles with wide distribution are formed. The morphology of Ag nanoparticles changes to hollow and sandwiched nanoparticles by Cu^＋ ion irradiation to doses of 3×10^16 and 5×10^16 ions/cm^2. The optical absorption properties of Ag nanoparticles are also tailored by these ways.

关键词： Nanoparticles Ion implantation Transmission electron microscopy

Numerical study of convective heat transfer of a supersonic combustor with varied inlet flow conditions

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Acta Mechanica Sinica 2019年第5期35卷 943-953页

作者： W.H.fan f.Q.Zhong S.G.Ma x.Y.Zhang State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190 China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Characteristics of convective heat transfer of a supersonic model combustor with variable inlet flow conditions were studied by numerical simulation in this *** three-dimensional flow and wall heat flux at different air inlet Mach numbers of 2.2,2.8 and 3.2 were studied numerically with Reynolds-averaged Navier-Stokes equations with a shear-stress transport(SST)k-ωturbulence model and a three-step reaction ***,ethylene was chosen as the fuel,and the fixed fuel-to-air equivalence ratio is 0.8 in all cases in this *** results of the simulations indicate that wall heat flux distribution of the combustor is very non-uniform with several peaks of wall heat flux at varied *** the low inlet Mach number of 2.2,a shock train structure is formed in the isolator,and three peaks of wall heat flux are located respectively on the backward face of the cavity,on the side wall near the fuel injection and on the bottom wall near the injection holes,and a maximum wall heat flux reaches 5.4 MW/*** the medium inlet Mach number of 2.8,there exists a much shorter shock structure with three peaks of wall heat flux similar to that of Mach number ***,as the inlet Mach number increased to 3.2,there is no shock structure upstream of fuel injections,and the combustor flow is in a supersonic mode with different locations and values of wall heat flux *** statistical results of wall heat loading show that the change of total wall heat is not monotonic with the increase of inlet Mach number,and the maximum appears in the case of Mach number being ***,for all the cases,the bottom wall takes up more than 50%of the total heat loading.

关键词： Wall heat flux Numerical simulation Ethylene Supersonic combustor

NUMERICAL INVESTIGATION ON fLOW CHARACTERISTICS IN RIBBED BEND

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Journal of Hydrodynamics 2001年第2期13卷 111-120页

作者： Yao, J. fan, J.R. Zhang, x.Y. Cen, K.f. Dept. of Energy Engineering Zhejiang Univ. Hangzhou 310027 China

Previous research by the author has proved that ribbed bend technology is a simple and efficient anti-erosion method. The present paper is a further study to unveil the mechanism of the technology by using numerical method. The flow characteristics in ribbed bend were studied. A k-Ε turbulence model was used and the simulations were carried out in the body-fitted coordinates. This procedure was confirmed to be credible by showing the satisfactory agreement between the predications and experimental results. It is concluded that the character of the longitudinal flow in ribbed bend especially in the concave parts between ribs has a beneficial effect on increasing the anti-erosion ability of ribbed bend but the secondary flow has little effect on determining the particle trajectory.

关键词： Boundary conditions Differential equations Erosion Mathematical models Numerical methods Three dimensional

Effect of Inorganic filler on Thermally Stimulated Current in Low-density Polyethylene

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Journal of Materials Science & Technology 1997年第3期13卷 223-226页

作者： Lei, QQ fan, Y Wang, x Lin, JQ xiong, YL Dept. of Electrical Materials Engineering Harbin University of Science and Technology Harbin 150040 China

By measuring the thermally stimulated current (TSC) spectra at various fields in low-density polyethylene with inorganic filler (f-LDPE) and comparing with those in LDPE, we found that their TSC spectra show significant distinction. In virtue of analysing change of peak current, peak temperature and activation energy with poling field, it can be depicted that the TSC in f-LDPE specimen comes from dipole relaxation of residual silanol groups on surface of filler, but the injected electrons in very high fields, no doubt, are captured in deeper traps, and they can not be released even near 100 degrees C. The filler (kaolin) plays a key role in changing the TSC spectra through deep and interfacial traps existing between the filler and the polymer matrix. Whereas, the TSC spectra of LDPE specimen possess marked characteristics of electron release from traps in amorphous-crystalline or crystalline region.

关键词： Low density polyethylenes