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Methods for Detection of Subsurface Damage:A Review

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 23-36页

作者： jing-fei Yin Qian Bai bi Zhang Key Laboratory for Precision and Non-traditional Machining of Ministry of Education Dalian University of Technology Department of Mechanical and Energy Engineering South University of Science and Technology

Subsurface damage is easily induced in machining of hard and brittle materials because of their particular mechani?cal and physical properties. It is detrimental to the strength,performance and lifetime of a machined part. To manu?facture a high quality part,it is necessary to detect and remove the machining induced subsurface damage by the subsequent processes. However,subsurface damage is often covered with a smearing layer generated in a machining process,it is rather di cult to directly observe and detect by optical microscopy. An e cient detection of subsur?face damage directly leads to quality improvement and time saving for machining of hard and brittle materials. This paper presents a review of the methods for detection of subsurface damage,both destructive and non?destructive. Although more reliable,destructive methods are typically time?consuming and confined to local damage infor?mation. Non?destructive methods usually su er from uncertainty factors,but may provide global information on subsurface damage distribution. These methods are promising because they can provide a capacity of rapid scan and detection of subsurface damage in spatial distribution.

关键词： Subsurface damage Hard and brittle material Taper polishing Measurement Laser scattering

Corrosion behavior of nickel-based 718 alloy determined by in situ electrochemical methods at different partial pressures of H2S in 25 wt% NaCl solution at 150℃

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Rare Metals 2019年第9期38卷 855-863页

作者： Yu-bi Zhang Xiao-liang Yang An Tang School of Mechanical Engineering Henan University of EngineeringZhengzhou 451191China Chongqing Materials Research Institute Co. LtdChonging 400707China

The corrosion behavior of nickel-based 718 alloy at seven partial pressures of H2 S(PH2 S)was investigated using electrochemical impedance spectroscopy(EIS)and polarization methods in 25 wt% NaCl solution at150℃ for 168 *** tested results show that anodic reactions are controlled alternately by the diffusion mostly,then both charge transfer and diffusion and finally charge transfer mainly with the increment of PH2 *** corrosive products are composed of sulfides and oxides of Ni,Cr and Fe with double layers for PH2 S of 5.1 and 13.0 MPa and three layers for PH2 S of 10.4 MPa according to microstructures and compositions of corrosion products characterized by the scanning electron microscope(SEM)and electron probe microanalysis(EPMA)*** inner oxides layer plays a critical role in anti-corrosion in a wet H2 S environment at high temperature and pressure.

关键词： Nickel-based 718 alloy Corrosion electrochemistry Polarization Passive film

Performance enhancement of perovskite solar cells with Cs2PtI6-xBrx absorber layer based on numerical simulation

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Optoelectronics Letters 2025年

作者： Du Zuyan Yuan Yujie Hou Guofu Xin Yupeng bi Jinlian Li Wei Tianjin Key Laboratory of Film Electronic and Communication Devices， School of Integrated Circuit Science and Engineering， Tianjin University of Technology Institute of Photoelectronic Thin Film Devices and Technology， Nankai University

Cs2TiBr6， characterized as a lead-free vacancy-ordered double perovskite material， demonstrates notable stability and photoelectric performance， rendering it suitable for application in perovskite solar cells. However， the experimental efficiency of this material is currently limited， achieving only 3.12%. This efficiency limitation primarily stems from the material’s wide bandgap， which results in insufficient light absorption. To address this issue， this study utilized Cs2PtI6-xBrxfor band structure fine-tuning. By adjusting the bandgap of Cs2PtI6-xBrxthrough Br-doping， not only was the alignment of the energy bandgap in the absorption layer effectively adjusted， but the cutoff range of light absorption was also significantly expanded. Setting the Cs2PtI6-xBrxbandgap to 1.4 eV resulted in optimal device performance. Additionally， comparative analyses aimed at boosting solar cell efficiency were performed on both hole transport and electron transport layer materials. Subsequently， the structure of the perovskite solar cell was optimized using an FTO/TiO2/Cs2TiBr6/Cs2PtI6-xBrx/Cu2O/Au configuration. Furthermore， the influence of the absorber layer thickness and defect density on device performance was studied. Ultimately， this configuration enabled the Cs2TiBr6/Cs2PtI6-xBrxsolar cell to achieve a peak conversion efficiency of 29.69%.

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Experimental and numerical study on dynamic mechanical behaviors of shale under true triaxial compression at high strain rate

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International Journal of Mining Science and Technology 2024年第2期34卷 149-165页

作者： Xiaoping Zhou Linyuan Han jing bi Yundong Shou School of Civil Engineering Wuhan UniversityWuhan 430072China College of Civil Engineering Guizhou UniversityGuiyang 550025China

High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing *** effectively extract shale gas,it is important to understand the dynamic mechanical properties of *** experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this *** dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are *** results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate *** characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial ***,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of *** dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D *** numerical results are in good agreement with the experimental data.

关键词： Dynamic behaviors True triaxial compression High strain rates Dynamic failure mechanism PFC3D-FLAC3D coupled method

Effect of Limestone on NO Emission during the Co-Combustion of Semi-Coke and bituminous Coal

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Journal of Thermal Science 2024年第6期33卷 2413-2425页

作者： LIU Yanquan TAN Wenyi liang Shaohua bi Xiaolong School of Energy&Engineering Nanjing Institute of TechnologyNanjing 211167China School of Environment Engineering Nanjing Institute of TechnologyNanjing 211167China

When semi-coke is co-combusted with bituminous coal with higher sulfur content in a circulating fluidized bed(CFB)boiler,the necessity of desulfurization in furnace ***,limestone,which is a widely used desulfurizing agent,also has an effect on NO *** order to explore its effect during co-combustion,the combustion experiments were conducted in both a CFB test rig and a fixed bed *** results show that blending semi-coke with bituminous coal will change the occurrence forms of nitrogen in the fuel and more fuel NO is released during the devolatilization *** the desulfurization process,CaO will be generated through the calcination *** has catalytic effects on both the oxidation and reduction reactions of NO,and the catalytic strength in these two types of reactions decides the final effect on NO *** the blended fuel with 50%semi-coke and 50%bituminous coal(SC50BC50),the NO emission initially increases and then decreases as the Ca/S molar ratio increases from 0 to 4 at 900℃.Compared to the situation of burning semi-coke alone,semi-coke in the blended fuel has more opportunities to contact with CaO under the same Ca/S molar ratio,leading to the heterogeneous reduction reaction of NO *** the combustion temperature increases from 800℃ to 1000℃,the effect of limestone on NO emission will change from promotion to *** is because the higher combustion temperature can intensify not only the catalytic reduction of NO precursors in the dense-phase region,but also the reaction between NO and unburnt char in the dilute-phase region in the ***,the lower O_(2) concentration in the atmosphere is also favorable for enhancing the catalytic effect of CaO on the NO-char reduction reaction for semi-coke and SC50BC50,so the conversion of fuel-N/NO will be inhibited compared with the cases without *** achievements of this study are beneficial for the coordinated control of NOx and SO_(2) during the

关键词： semi-coke co-combustion limestone NO emission

Paroxetine engenders analgesic effects through inhibition of p38 phosphorylation in a rat migraine model

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Neural Regeneration Research 2012年第13期7卷 1006-1012页

作者： Chuanming Wang Wei bi Yanran liang Xiuna jing Songhua Xiao Yannan Fang Qiaoyun Shi Enxiang Tao Department of Neurology Sun Yat-sen Memorial Hospital Sun Yat-sen University Guangzhou 510120 Guangdong Province China Department of Neurology First Affiliated Hospital of Jinan University Guangzhou 510630 Guangdong Province China Department of Neurology First Affiliated Hospital Sun Yat-sen University Guangzhou 510080 Guangdong Province China Center for Inherited Cardiovascular Disease Division of Cardiovascular Medicine Stanford University School of Medicine Stanford CA 94304 USA

In this study, a model of migraine was established by electrical stimulation of the superior sagittal sinus in rats. These rats were then treated orally with paroxetine at doses of 2.5, 5, or 10 mg/kg per day for 14 days. Following treatment, mechanical withdrawal thresholds were significantly higher, extracellular concentrations of 5-hydroxytryptamine in the periaqueductal grey matter and nucleus reticularis gigantocellularis were higher, and the expression of phosphorylated p38 in the trigeminal nucleus caudalis was lower. Our experimental findings suggest that paroxetine has analgesic effects in a rat migraine model, which are mediated by inhibition of p38 phosphorylation.

关键词： paroxetine migraine 5-hydroxytryptamine p38 phosphorylation neural regeneration

An unexpected approach to enhance specific surface area and mesopore amount of polyaniline by Zn doping

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Rare Metals 2024年第9期43卷 4585-4594页

作者： Zhi-Da Zhu Yu-Zhe Han Xiao-bi jing School of Mechanical Engineering Yangzhou UniversityYangzhou 225127China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Poly-p-anisidine could be easily fabricated via the oxidative polymerization reaction of p-anisidine using H_(2)O_(2)as the green *** was unexpectedly found that zinc doping could significantly improve the adsorption ability of the material versus heavy metals such as Pb,Cu,Pd,Ag and *** of nitrogen adsorption–desorption experiments demonstrated that Zn doping could enhance the specific surface area and mesopore amount of the prepared material,which might facilitate its absorption to *** work not only provides a novel material for the treatment of heavy metal-polluted water but also leads to a nice mesoporous catalyst support for environment protection and organic synthesis,*** Zn-doped poly-panisidine can be employed as the catalyst support to prepare Cu@PANI-OMe/Zn or Pd@PANI-OMe/Zn for the oxidative degradation reaction of phenol or Suzuki–Miyaura coupling reactions,*** discloses a new strategy for fabricating the mesoporous polyaniline materials with profound application potential.

关键词： Surfaces Porous materials Rare metal concentration Adsorption Catalysis

Patch nearfield acoustic holography combined with sound field separation technique applied to a non-free field

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Science China(Physics,Mechanics & Astronomy) 2015年第2期58卷 33-41页

作者： bi ChuanXing ING WenQian ZHANG Yongbin XU liang Institute of Sound and Vibration Research Hefei University of Technology

The conventional nearfield acoustic holography(NAH) is usually based on the assumption of free-field conditions, and it also requires that the measurement aperture should be larger than the actual source. This paper is to focus on the problem that neither of the above-mentioned requirements can be met, and to examine the feasibility of reconstructing the sound field radiated by partial source, based on double-layer pressure measurements made in a non-free field by using patch NAH combined with sound field separation technique. And also, the sensitivity of the reconstructed result to the measurement error is analyzed in detail. Two experiments involving two speakers in an exterior space and one speaker inside a car cabin are presented. The experimental results demonstrate that the patch NAH based on single-layer pressure measurement cannot obtain a satisfied result due to the influences of disturbing sources and reflections, while the patch NAH based on double-layer pressure measurements can successfully remove these influences and reconstruct the patch sound field effectively.

关键词： nearfield acoustic holography sound field separation equivalent source method

Novel Method for Selection of Regularization Parameter in the Near-field Acoustic Holography

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 285-292页

作者： ZHANG Yongbin bi Chuanxing XU liang CHEN Xinzhao Institute of Sound and Vibration Research Hefei University qf Technology Hefei 230009 China

Because of the ill-posedness of the near-field acoustic holography（NAH）,the regularization method is required to stabilize the computational process of *** regularization effect is related to how to select the parameter correctly and *** the L-curve method commonly used for the selection of regularization parameters has the disadvantages of wrong selection and incorrect selection,which influences the application of *** the purpose of solving the problems existed in the L-curve method,the （？）-curve method is introduced into the field of NAH,and the performance applied to NAH directly is analyzed on the basis of equivalent source method-based ***,it is found out via investigations that the（？）-curve method in NAH also has the problem of wrong selection and is unable to choose the regularization parameter *** order to select the parameter correctly and effectively,a novel method for selecting regularization parameters is proposed based on the original（？）-curve method,which can be called improved （？）-curve *** the proposed method the regularization parameters are discretized linearly between the largest singular value and the smallest singular value,and the solution norm and the residual norm corresponding to these regularization parameters are also described in a linear coordinate instead of in a lg-lg coordinate,which are the two main differences compared with the L-curve and with the original（？）-curve *** linear coordinate and using the linearly discretized regularization parameters,the solution norm is a monotonically decreasing function of the residual norm as the increase of the regularization parameter,moreover the curve is convex *** the regularization parameters can be selected correctly and effectively based on the improved（？）-curve *** a numerical simulation is done with a simply supported plate to verify the validity of the proposed *** with two actual sources,a clamped plat

关键词： near-field acoustic holography(NAH) regularization parameter selection