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SILICON MICRO-TRENCH ETCHINg USINg HIgH-DENSITY PLASMA ETCHER

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 397-402页

作者： T.T.Sun z.g.liu H.C.Yu M.B.Chen J.M.Miao PhysicsDepartmentofShanghaiJiaotongUniversity Shanghai200240China／／MicromachineCenterSchoolofMechanicalandProductionEngineeringNanyangTechnologicalUniversity639798Singapore PhysicsDepartmentofShanghaiJiaotongUniversity Shanghai200240China MicromachineCenter SchoolofMechanicalandProductionEngineeringNanyangTechnologicalUniversity639798Singapore

Dry etching of silicon is an essential process step for the fabrication of Micro electromechancal system (MEMS). The Az7220 positive photo-resist was used as the etching mask and silicon micro-trenches were fabricated with a multiplexed indu ctively coupled plasma (ICP) etcher. The influence of resist pattern profile, an d etch condition on sidewall roughness were investigated detail. The results sho w that the sidewall roughness of micro-trench depends on profiles of photo-resis t pattern, the initial interface between the resist bottom surface and silicon s urface heavily. The relationship between roughness and process optimization para meters are presented in the paper. The roughness of the sidewall has been decrea sed to a 20-50nm with this experiment.

关键词： deep RIE silicon etching micro-trench photo-resist

THE LIQUIDUS OF THE TERNARY Ag-Cu-Si ALLOY SYSTEM

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 325-328页

作者： z.g.liu X.M.Luo g.S.guo C.X.He g.B.Li Q.Y.zhang Inst of Precious Metals Kunming China

The liquidus of the ternary Ag-Cd-Si alloy system in the Ag-Cu rich region was determined by DTA. The ternary Ag-Cd-Si system was divided into two ternary systems Ag-Cu-Cuo.76Si0.24 and Ag-Cu0.76Si0.24-Si by the section of Ag-Cu0.76 *** is one ternary eutectic point for both the systems with the composition of 12. 5at. %Ag+71. 7at.%Cu+15.8at. %Si and 30at.% Ag+44.7at.%Cu+25.3at.%Sirespectivelg and the temperatures of the eutectic points are 740 and 705℃ respectively.

关键词： Ag-Cd-Si ternary sytem liquidus

Enhanced pitting corrosion resistance of a zr-based metallic glass by ultraviolet light irradiation

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Journal of Iron and Steel Research International 2023年第8期30卷 1642-1649页

作者： z.Chen D.P.Wang S.Wang Y.X.geng Y.X.guo Y.C.Wu z.g.liu Y.Y.zhang Y.X.Wang School of Materials Science and Engineering Jiangsu University of Science and Technology.Zhenjiang 212003JiangsuChina School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina

The influence of ultraviolet light irradiation on the pitting corrosion performance of a zr_(2)Ni metallic glass was examined using electrochemical methods and immersion test in 0.05 mol/L NaCl *** the results of potentiostatic polarization,the pitting potential of the ultraviolet light-irradiated sample shifted positively with a value of~300 mV,revealing the enhanced pitting corrosion resistance of the *** corrosion morphology after the immersion test also demonstrated lower degree of corrosion damage and improved pitting resistance of the sample with ultraviolet light irradiation.X-ray photoelectron spectroscopy analysis revealed more zirconium enrichment in the passive film and no chloride ions adsorption for the samples with ultraviolet irradiation,accounting for the suppression of the pit generation and *** findings indicate that ultraviolet light irradiation improves the pitting corrosion resistance of the zr-based metallic glasses,which are promising structural materials to be used in corrosion environments with high ultraviolet irradiation.

关键词： Metallic glass Pitting-Corrosion Ultraviolet light irradiation Passive film

Corrosion and cavitation erosion resistance enhancement of cast Ni–Al bronze by laser surface melting

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Journal of Iron and Steel Research International 2022年第2期29卷 359-369页

作者： Q.N.Song Y.Tong H.L.Li H.N.zhang N.Xu g.Y.zhang Y.F.Bao W.liu z.g.liu Y.X.Qiao Engineering Research Center of Dredging Technology of Ministry of Education Hohai UniversityChangzhou213022JiangsuChina College of Mechanical and Electrical Engineering Hohai UniversityChangzhou213022JiangsuChina College of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003JiangsuChina

Laser surface melting (LSM) was applied on a cast Ni–Al bronze (NAB), which was a crucial material for marine ship propellers. A 720 μm-thick LSM layer with fine equiaxed and dendritic microstructures was obtained. After immersion for 30 days, the corrosion rate of cast NAB was reduced by 25% after LSM. Preferential corrosion occurred and deep corrosion pits appeared at α + κIII microstructure for the cast NAB. LSM NAB underwent general corrosion, and a much more protective film formed on the surface because of the homogenized microstructure. The mass loss of the cast NAB was approximately 2.1 times larger than that of LSM NAB after cavitation erosion (CE) in 3.5 wt.% NaCl solution for 5 h. For the two materials, the mechanical impact effect was dominantly responsible for CE damage. Therefore, the improved hardness and homogenized microstructure contributed to the improved CE resistance of LSM NAB. CE destructed the film, shifted the open circuit potential toward a more negative value, and raised the current density by an order of magnitude. Corrosion at the cast eutectoid microstructure and the dendrites of LSM NAB facilitates the degradation under the cavitation attack. CE-corrosion synergy was largely caused by corrosion-enhanced-CE.

关键词： Laser surface melting Ni-Al bronze Microstructure Corrosion Cavitation erosion Synergy

The Fluid-Structure Interaction Simulation on A Cylinder Subjected to An Annular Flow

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The Fluid-Structure Interaction Simulation on A Cylinder Sub...

Damage analysis caused by ^(60)Co ions in functionally graded materials

The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-Hong Kong Forum on Mechanics and Its Application 2012

作者： Y.liu z.g.liu J.Lu Department of Mechanical Engineering The Hong Kong Polytechnic University Department of Mechanical and Biomedical Engineering City University of Hong Kong

The fluid-structure interaction of a model where a clamped-clamped cylinder(shown in Fig. 1) is subjected to an annular turbulent flow is simulated based on the arbitrary Lagrange-Euler(ALE) N-S equations with the LES model and Euler-Bernoulli beam dynamic *** to the theoretical analysis,at small dimensionless flow velocity u,the vibration of the cylinder induced by flow is very weak;when the dimensionless flow velocity increases large enough,the instabilities due to bucking and flutter would *** analyses are mainly based on some assumptions such as constant flow velocity and include many empirical *** thoroughly analyse this problem, the numerical simulation is *** simulation results(Fig.2) capture the phenomena of instability and indicates that the nonlinear theory is more appropriate to explain the instability *** numerical solution shows the bifurcation of the solution at certain dimensionless velocity,indicating the dominant effect of non-linearity.

关键词： The Fluid-Structure Interaction Simulation on A Cylinder Subjected to An Annular Flow

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Defence Technology(防务技术) 2025年第2期44卷 248-256页

作者： zübeyde Özkan Ugur gökmen Sema Bilge Ocak Department of Advanced Technologies Graduate School of Natural and Applied SciencesGazi UniversityAnkara06560Turkiye Department of Metallurgical and Materials Engineering Faculty of TechnologyGazi UniversityAnkara 06560Turkiye Basic and Engineering Sciences Central Laboratory Application and Research Center Gazi UniversityAnkara 06560Turkiye

Functionally graded composite/hybrid materials(FgCM/FgHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 *** analysis of the damage caused by^(60) ions'(1.173-1.1332 MeV)on the material was examined using the SRIM/TRIM Monte Carlo simulation *** the simulation,the following data regarding the atoms of the target materials were obtained:ion distribution,target ionization,total displacements,surface binding energy,lattice binding energy,and displacement *** the studied four materials,the one with the highest ion range value was found to be AA6082 with ***_(2)was found to be the reinforcement material that reduced the ion range the most in the *** to its high binding energy,B_(4)C reinforced AA6082+(0-50%)B_(4)C FgCM was found to have the least vacancy with 4782/ion.

关键词： SRIM/TRIM Damage analysis AA6082 ^(60)Co ion

Discovering causal models for structural,construction and defense-related engineering phenomena

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Defence Technology(防务技术) 2025年第1期43卷 60-79页

作者： M.z.Naser School of Civil&Environmental Engineering and Earth Sciences(SCEEES) Clemson UniversityClemsonSouth Carolina 29634USA The Artificial Intelligence Research Institute for Science and Engineering(AIRISE) Clemson UniversityClemsonSouth Carolina 29634USA

Causality,the science of cause and effect,has made it possible to create a new family of *** models are often referred to as causal *** those of mathematical,numerical,empirical,or machine learning(ML)nature,causal models hope to tie the cause(s)to the effect(s)pertaining to a phenomenon(i.e.,data generating process)through causal *** paper presents one of the first works at creating causal models in the area of structural and construction *** this end,this paper starts with a brief review of the principles of causality and then adopts four causal discovery algorithms,namely,PC(Peter-Clark),FCI(fast causal inference),gES(greedy equivalence search),and gRa SP(greedy relaxation of the sparsest permutation),have been used to examine four phenomena,including predicting the load-bearing capacity of axially loaded members,fire resistance of structural members,shear strength of beams,and resistance of walls against impulsive(blast)*** from this study reveal the possibility and merit of discovering complete and partial causal ***,this study also proposes two simple metrics that can help assess the performance of causal discovery algorithms.

关键词： Causality Causal discovery Directed acyclic graphs Machine learning Metrics

Thermal fracture analysis of two collinear cracks in a functionally graded medium based on the three-phase-lag model

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Applied Mathematics and Mechanics(English Edition) 2025年第3期46卷 501-520页

作者： zhangna XUE Huameng WANg Jianlin liu Minjie WEN z.T.CHEN College of Pipeline and Civil Engineering China University of Petroleum(East China) School of Civil Engineering and Architecture Zhejiang Sci-Tech University Department of Mechanical Engineering University of Alberta

The three-phase-lag(TPL) heat conduction model is an accurate representation of the actual heat transfer process. It would be interesting to investigate how the TPL model affects the thermal fracture behavior when there are defects existing in the medium. This paper aims to analyze the thermoelastic responses of two collinear cracks within a functionally graded half-space under thermal loadings by means of the TPL model. The thermoelastic problem is transformed into a series of singular integral equations using the integral transformation methods. The transient temperature and stress intensity factors(SIFs) are obtained through the application of Chebyshev *** effects of crack spacing and non-homogeneous parameters on the transient thermoelastic responses are presented, and the results of the TPL model are compared with those of the Fourier model, Cattaneo and Vernotte(CV) model, and dual-phase-lag(DPL)model. It is shown that crack spacing and non-homogeneous parameters have important effects on the thermoelastic responses, and the fluctuation phenomenon under the TPL model is the most pronounced due to the existence of the thermal displacement lag term.

关键词： Chebyshev polynomials

Arsenic methylation and microbial communities in paddy soils under alternating anoxic and oxic conditions

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Journal of Environmental Sciences 2025年第2期148卷 468-475页

作者： Jing liu Rui Pei Runzeng liu Chuanyong Jing Wenjing liu Shandong Key Laboratory of Environmental Processes and Health School of Environmental Science and EngineeringShandong UniversityQingdao 266237China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Arsenic(As)methylation in soils affects the environmental behavior of As,excessive accumulation of dimethylarsenate(DMA)in rice plants leads to straighthead disease and a serious drop in crop *** the mobility and transformation of methylated arsenic in redox-changing paddy fields is crucial for food ***,soils including unarsenic contaminated(N-As),low-arsenic(L-As),medium-arsenic(M-As),and high-arsenic(H-As)soils were incubated under continuous anoxic,continuous oxic,and consecutive anoxic/oxic treatments respectively,to profile arsenic methylating process and microbial species involved in the As *** anoxic-oxic(A-O)treatment,methylated arsenic was significantly increased once oxygen was introduced into the incubation *** methylated arsenic concentrations were up to 2-24 times higher than those in anoxic(A),oxic(O),and oxic-anoxic(O-A)treatments,under which arsenic was methylated slightly and then decreased in all four As concentration *** fact,the most plentiful arsenite S-adenosylmethionine methyltransferase genes(arsM)contributed to the increase in As ***(40.8%-62.4%),Firmicutes(3.5%-15.7%),and Desulfobacterota(5.3%-13.3%)were the major microorganisms related to this *** microbial increasedmarkedly and played more important roles after oxygen was introduced,indicating that they were potential keystone microbial groups for As methylation in the alternating anoxic(flooding)and oxic(drainage)*** novel findings provided newinsights into the reoxidation-driven arsenic methylation processes and the model could be used for further risk estimation in periodically flooded paddy fields.

关键词： Arsenic methylation Anoxic-oxic Straighthead disease arsM gene Microbial community