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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

Formation of subsurface cracks in silicon wafers by grinding

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Nanotechnology and Precision Engineering 2018年第3期1卷 172-179页

作者： Jingfei Yin qian bai Yinnan Li Bi Zhang Key Laboratory for Precision and Non-traditional Machining of Ministry of Education Dalian University of Technology College of Engineering Southern University of Science and Technology

Single-crystal silicon is an important material in the semiconductor and optical ***,being hard and brittle,a silicon wafer is vulnerable to subsurface cracks(SSCs)during grinding,which is detrimental to the performance and lifetime of a wafer ***,studying the formation of SSCs is important for optimizing SSC-removal processes and thus improving surface *** this study,a statistical method is used to study the formation of SSCs induced during grinding of silicon *** statistical results show that grinding-induced SSCs are not stochastic but anisotropic in their ***,when grinding with coarse abrasive grains,SSCs form along the cleavage planes,primarily the{111}***,when grinding with finer abrasive grains,SSCs tend to form along planes with a fracture-surface energy higher than that of the cleavage *** findings provide a guidance for the accurate detection of SSCs in ground silicon wafers.

关键词： Silicon wafer Subsurface crack Cleavage Inclination angle Thermal energy

Stress-Induced Deformation of Thin Copper Substrate in Double-Sided Lapping

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 80-89页

作者： Jiang Guo Zengxu He Bo Pan Bin Wang qian bai Jinxing Kong Renke Kang State Key Laboratory of High-Performance Precision Manufacturing Department of Mechanical EngineeringDalian University of TechnologyDalian116024China Institute of Mechanical Manufacturing Technology China Academy of Engineering PhysicsMianyang621999China

Double-sided lapping is an precision machining method capable of obtaining high-precision ***,during the lapping process of thin pure copper substrate,the workpiece will be warped due to the influence of residual stress,including the machining stress and initial residual stress,which will deteriorate the flatness of the workpiece and ultimately affect the performance of *** this study,finite element method(FEM)was adopted to study the effect of residual stress-related on the deformation of pure copper substrate during double-sided *** the initial residual stress of the workpiece,the stress caused by the lapping and their distribution characteristics,a prediction model was proposed for simulating workpiece machining deformation in lapping process by measuring the material removal rate of the upper and lower surfaces of the workpiece under the corresponding *** results showed that the primary cause of the warping deformation of the workpiece in the doublesided lapping is the redistribution of initial residual stress caused by uneven material removal on the both *** finite element simulation results were in good agreement with the experimental results.

关键词： Machining deformation Double-sided lapping Residual stress Finite element simulation

Analysis of the influence of geometrical parameters of circular steel pipe with flange plate on the jacking force

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Underground Space 2022年第3期7卷 324-336页

作者： Zhiguo Wang Wen Zhao He Wang Yang Chen qian bai Shengang Li College of Resources and Civil Engineering Northeastern UniversityShenyangChina Dalian University of Technology DalianChina School of Civil Engineering and Architecture Xi’an University of TechnologyXi’anChina

Jacking force is one of the important safety indicators during pipe jacking *** models for calculating jacking force are widely used in the calculation of jacking force for pipe with regular *** this paper,considering pipe-soil interaction,the cross-sectional characteristics and the distribution characteristics between pipe and soil,the calculation equations for the jacking force of circular steel pipe with flange plate were proposed based on the pressure arch *** proposed equations were applied to calculate the jacking force for the Olympic Sports Center Subway Station of Line 9 in Shenyang,China,and the results were compared with the field monitoring data to predict the accurate jacking *** on the proposed equations,the influences of the flange plate position and steel pipe diameter on earth pressure around the pipe were *** functional relationship between the earth pressure and the position of flange plate or the pipe diameter was obtained,which provides design basis and theoretical guidance for engineering practice.

关键词： Pipe jacking Flange plate Jacking force Pressure arch theory Earth pressure STS pipe roofing method

Nitric Oxide-Releasing Poly(L-glutamic acid)Hybrid Hydrogels for Accelerating Diabetic Wound Healing

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Chinese Journal of Chemistry 2023年第17期41卷 2103-2112页

作者： Lin Teng Yingying Song Lingli Hu qian bai Xueliang Zhang Chang-Ming Dong Schoolof Chemistry and Chemical Engineering Frontiers Science Centerfor Transformative MoleculesShanghai Key Laboratory o Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Department of Environmental Health Schoolof Public HealthShanxi Medical UniversityTaiyuanShanxi 030012China

Comprehensive Summary,Diabetic wound healing is threatening worldwide and challenging in wound *** to inhibit heavy inflammation and bacterial infection in diabetic wounds,herein,we facilely construct a kind of NO-releasing poly(L-glutamic acid)(PGA)based graphene oxide(GO)hybrid hydrogel of HDGS at a lower solid percentage,presenting large microporous size of about 20μm,mild photothermal conversion property,and good *** improving hemostasis performance,the less amount of GO endowed the hydrogel with near infrared(NIR)responsivity to control fast and pulsatile NO release for killing bacteria and inhibiting heavy inflammation to proheal diabetic wound,in which a broad spectrum of antibacterial activities toward killing ***,*** and MRSA was achieved via a combined effect of photothermia and NO *** vivo effective hemostasis was attained in a rat liver bleeding model with short hemostatic time of~20 s and lower blood loss of 1.5%—2.0%.Moreover,the treatment of HDGS plus 4 times of mild NIR irradiation(10 min,808 nm,1 W/cm^(2)per time)performed superior full diabetic wound healing within 11—14 d,in which the regenerated skins were characteristic of thick epidermis/dermis,dense blood vessels,some hair follicles-embedding,and high level of collagens.

关键词： Polypeptide Hydrogel Nitric oxide Diabetic wound Wound healing Wound dressings

Construction of shallow buried large-span metro stations using the small pipe roof-beam method

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 122-136页

作者： qian bai Wen ZHAO Yingda ZHANG Pengjiao JIA Xiangrui MENG Bo LU Xin WANG Dazeng SUN School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China Centre for Infrastructure Engineering and Safety School of Civil and Environmental EngineeringThe University of New South WalesNSW 2052Australia School of Rail Transportation Soochow UniversitySuzhou 215131China China Northeast Architectural Design and Research Institute Co. Ltd.Shenyang 110006China

In relation to the Shifu Road Station project on Line 4 of the Shenyang Metro in China,a small-pipe roof-beam method for constructing subway stations is ***,a numerical simulation was performed to optimize the supporting parameters of the proposed method and determine the design ***,the deformation of the pipe roof and surface settlement during the construction process were ***,the surface settlement attributed to the excavation was studied through field monitoring,and the proposed method was compared with other *** results show that an increase in the pipe-roof spacing has little effect on the surface settlement and piperoof *** bearing capacity of the pipe roof can be efficiently utilized once the flexural stiffness reaches 2EI,and the flexural stiffness is not the dominant factor controlling the *** essential stages in controlling surface settlement are the excavations of the transverse pilot tunnels and the soil between *** final settlement value of the ground was 24.1 mm,resulting in a reduction in the construction period by at least five months while satisfying the control requirements.

关键词： subway station pipe-roof method surface settlement simulation on-site monitoring

Valproate reduces retinal ganglion cell apoptosis in rats after optic nerve crush

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Neural Regeneration Research 2023年第7期18卷 1607-1612页

作者： Feng Pan Dan Hu Li-Juan Sun qian bai Yu-Sheng Wang Xu Hou Eye Institute of Chinese PLA and Department of Ophthalmology Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina

The retinal ganglion cells of the optic nerve have a limited capacity for self-repair after *** is a histone deacetylase inhibitor and multitarget drug,which has been demonstrated to protect retinal *** this study,we established rat models of optic nerve-crush injury and injected valproate into the vitreous cavity immediately after *** evaluated changes in the ultrastructure morphology of the endoplasmic reticulum of retinal ganglion cells over time via transmission electron *** and western blot assay revealed that valproate upregulated the expression of the endoplasmic reticulum stress marker glucose-regulated protein 78 and downregulated the expression of transcription factor C/EBP homologous protein,phosphorylated eukaryotic translation initiation factor 2α,and caspase-12 in the endoplasmic reticulum of retinal ganglion *** findings suggest that valproate reduces apoptosis of retinal ganglion cells in the rat after optic nerve-crush injury by attenuating phosphorylated eukaryotic translation initiation factor 2α-C/EBP homologous protein signaling and caspase-12 activation during endoplasmic reticulum *** findings represent a newly discovered mechanism that regulates how valproate protects neurons.

关键词： apoptosis C/EBP homologous protein caspase-12 endoplasmic reticulum glucose-regulated protein 78 optic nerve crush phosphorylated eukaryotic translation initiation factor 2α retinal ganglion cells unfolded protein response valproate

Vacuolar Phosphate Transporter1 (VPT1) may transport sugar in response to soluble sugar status of grape fruits

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Horticulture Research 2023年第2期10卷 94-105页

作者： qian bai Xuexue Chen Zhenzhen Zheng Jinjing Feng Yanjun Zhang Yuanyue Shen Yun Huang Beijing Key Laboratory for Agricultural Application and New Technique College of Plant Science and TechnologyBeijing University of AgricultureBeijing 102206China Ministry of Education Key Laboratory of Silviculture and Conservation College of ForestryBeijing Forestry University35 East Qinghua RoadBeijing 100083China

Vacuolar Phosphate Transporter1(VPT1)-mediated phosphate uptake in the vacuoles is essential to plant development and fruit ***,here we find that the VPT1 may transport sugar in response to soluble sugar status of *** VvVPT1 protein isolated from grape(Vitis vinifera)berrieswas tonoplast-localized and contains SPX(Syg1/Pho81/XPR1)and MFS(major facilitator superfamily)*** mRNA expression was significantly increased during fruit ripening and induced by *** analyses based on transient transgenic systems in grape berry showed that VvVPT1 positively regulated berry ripening and significantly affected hexose contents,fruit firmness,and ripening-related gene *** VPT1 proteins(Grape VvVPT1,strawberry FaVPT1,and Arabidopsis AtVPT1)all showed low affinity for phosphate verified in yeast system,while they appear different in sugar transport capacity,consistent with fruit sugar ***,our findings reveal a role for VPT1 in fruit ripening,associated to its SPX and MFS domains in direct transport of soluble sugar available into the vacuole,and open potential avenues for genetic improvement in fleshy fruit.

关键词： sugar fir transport

Intracerebral haemorrhage: from clinical settings to animal models

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Stroke & Vascular Neurology 2020年第4期5卷 388-395页

作者： qian bai Zhaofu Sheng Yang Liu Ruiyi Zhang Voon Wee Yong Mengzhou Xue The Departments of Cerebrovascular Diseases Henan Medical Key Laboratory of Translational Cerebrovascular DiseasesThe Second Affiliated Hospital of Zhengzhou UniversityZhengzhouChina Hotchkiss Brain Institute and Department of Clinical Neurosciences University of CalgaryCalgaryAlbertaCanada

Spontaneous intracerebral haemorrhage(ICH)is a devastating type of stroke with high mortality and morbidity and for which no effective treatments are available to *** experimental and clinical research have been performed to explore its mechanisms regard the subsequent inflammatory cascade and to seek the potential therapeutic *** aim of this review is to discuss insights from clinical settings that have led to the development of numerous animal models of *** of the current and future challenges for clinicians to understand ICH are also surveyed.

关键词： clinical mortality cerebral