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Acoustic emission assessment of interface cracking in thermal barrier coatings

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Acta Mechanica Sinica 2016年第2期32卷 342-348页

作者： Li Yang Zhi-chun Zhong yi-chun zhou Wang Zhu Zhi-Biao Zhang Can-ying Cai chun-Sheng Lu Key Laboratory of Key Film Materials & Application for Equipment (Hunan Province) School of Materials Science and EngineeringXiangtan University Key Laboratory of Low Dimensional Materials & Application Technology (Ministry of Education) School of Materials Science and EngineeringXiangtan University Department of Mechanical Engineering Curtin University

In this paper,acoustic emission（AE） and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under *** interface failure process can be identifie via its AE features,including buckling,delamination incubation and *** to the Fourier transformation of AE signals,there arefourdifferentfailuremodes：surfaceverticalcracks,opening and sliding interface cracks,and substrate *** characteristic frequency of AE signals from surface vertical cracks is 0.21 MHz,whilst that of the two types of interface cracks are 0.43 and 0.29 MHz,*** energy released of the two types of interface cracks are 0.43 and 0.29 MHz,*** on the energy released from cracking and the AE signals,a relationship is established between the interface crack length and AE parameters,which is in good agreement with experimental results.

关键词： Thermal barrier coatings Acoustic emission Interface cracking Crack type Quantitative analysis

Reliability assessment on interfacial failure of thermal barrier coatings

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Acta Mechanica Sinica 2016年第5期32卷 915-924页

作者： Jin-Wei Guo Li Yang yi-chun zhou Li-Min He Wang Zhu Can-ying Cai chun-Sheng Lu Key Laboratory of Key Film Materials & Application for Equipment (Hunan Province) School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Key Laboratory of Low Dimensional Materials & Application Technology (Ministry of Education) School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Beijing Institute of Aeronautical Materials Beijing 100095China Department of Mechanical Engineering Curtin UniversityPerthWestern Australia 6845Australia

Thermal barrier coatings（TBCs） usually exhibit an uncertain lifetime owing to their scattering mechanical properties and severe service conditions. To consider these uncertainties, a reliability assessment method is proposed based on failure probability analysis. First, a limit state equation is established to demarcate the boundary between failure and safe regions, and then the failure probability is calculated by the integration of a probability density function in the failure area according to the first- or second-order *** is shown that the parameters related to interfacial failure follow a Weibull distribution in two types of TBC. The interfacial failure of TBCs is significantly affected by the thermal mismatch of material properties and the temperature drop in service.

关键词： Reliability assessment Thermal barrier coatings Interfacial failure

Residual stress in the cylindrical drawing cup of SUS304 stainless steel evaluated by split-ring test

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Acta Mechanica Sinica 2016年第1期32卷 125-134页

作者： Liang-Hong Xiao Dao-He Yuan Jun-Zhong Xiang Jin-Gang Liu yi-chun zhou School of Mechanical Engineering Xiangtan University Key Laboratory of Low Dimensional Materials & Application Technology Xiangtan University Ministry of Education

The residual stresses in the wall of a SUS304 stainless steel cylindrical drawing cup were evaluated by split-ring tests, and the influences of stamping die parame- ters on the residual stress were investigated. A new theoretical model of a split-ring test was developed to evaluate the resid- ual stress in a ring, which was verified to be reasonable and reliable by numerical simulations with ABAQUS code and by nanoindentation tests. Seven groups of split-ring tests were completed, and the residual stresses were calculated according to the theoretical model. The split-ring test results showed that the circumferential residual stress in the wall of the SUS304 stainless steel cylindrical drawing cup was very large and did not change with the different die comer radius. The circumferential residual stress first increased with the increase of drawing punch-die clearance, then was almost unchanged when the clearance increased greater than blank thickness 1 mm. Thus, a smaller clearance was suggested to be chosen to reduce the residual stress in the wall of the SUS304 stainless steel drawing cup.

关键词： Residual stress Split-ring test FEM numericalsimulation SUS304 stainless steel Nanoindentation

Heterogeneous integration of GaSb layer on(100)Si substrate by ion-slicing technique

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Chinese Physics B 2022年第7期31卷 442-447页

作者： Ren-Jie Liu Jia-Jie Lin Zheng-Hao Shen Jia-Liang Sun Tian-Gui You Jin Li Min Liao yi-chun zhou Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and EngineeringXiangtan UniversityXiangtan 411105China Hunan Provincial Key Laboratory of Thin Film Materials and Devices School of Materials Science and EngineeringXiangtan UniversityXiangtan 411105China College of Information Science and Engineering Jiaxing UniversityJiaxing 314001China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Science(CAS)Shanghai 200050China Beijing Semicore ZKX Electronics Equipment Co. LtdBeijing 100000China

Integration of the high-quality Ga Sb layer on an Si substrate is significant to improve the Ga Sb application in optoelectronic *** this work,a suitable ion implantation fluence of 5×10^(16)-cm^(-2)H ions for Ga Sb layer transfer is *** the strain change and the defect evolution,the blistering and exfoliation processes of Ga Sb during annealing is revealed in *** the direct wafer bonding,the Ga Sb layer is successfully transferred onto a(100)Si substrate covered by 500-nm thickness thermal oxide SiO_(2)*** being annealed at 200℃,the Ga Sb layer shows high crystalline quality with only 77 arcsec for the full width at half maximum(FWHM)of the x-ray rocking curve(XRC).

关键词： ion-slicing technique heterogeneous integration GaSbOI

Malicious Document Detection Based on GGE Visualization

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Computers, Materials & Continua 2025年第1期82卷 1233-1254页

作者： Youhe Wang yi Sun Yujie Li Chuanqi zhou Henan Province Key Laboratory of Information Security Information Engineering UniversityZhengzhou450000China

With the development of anti-virus technology,malicious documents have gradually become the main pathway of Advanced Persistent Threat(APT)attacks,therefore,the development of effective malicious document classifiers has become particularly ***,detection methods based on document structure and behavioral features encounter challenges in feature engineering,these methods not only have limited accuracy,but also consume large resources,and usually can only detect documents in specific formats,which lacks versatility and *** address such problems,this paper proposes a novel malicious document detection method-visualizing documents as GGE images(Grayscale,Grayscale matrix,Entropy).The GGE method visualizes the original byte sequence of the malicious document as a grayscale image,the information entropy sequence of the document as an entropy image,and at the same time,the grayscale level co-occurrence matrix and the texture and spatial information stored in it are converted into grayscale matrix image,and fuses the three types of images to get the GGE color *** Convolutional Block Attention Module-EfficientNet-B0(CBAM-EfficientNet-B0)model is then used for classification,combining transfer learning and applying the pre-trained model on the ImageNet dataset to the feature extraction process of GGE *** shown in the experimental results,the GGE method has superior performance compared with other methods,which is suitable for detecting malicious documents in different formats,and achieves an accuracy of 99.44%and 97.39%on Portable Document Format(PDF)and office datasets,respectively,and consumes less time during the detection process,which can be effectively applied to the task of detecting malicious documents in real-time.

关键词： Malicious document visualization EfficientNet-B0 convolutional block attention module GGE image

Flexible and wake-up free Hf_(0.5)Zr_(0.5)O_(2) ferroelectric thin films with ultra-low operation voltage and high polarization

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Journal of Advanced Ceramics 2024年第11期13卷 1844-1851页

作者： Jun-Hui Wang Tian-Peng Duan Jia-Jia Liao Zhi-Peng Wang Xin-Ran Huang Shi-Jie Jia Ke-Yu Bao Yu-Xin Fan Bing-Jian Zeng Li-Mei Jiang Min Liao yi-chun zhou Qiong Yang Jie Jiang School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Guangzhou Institute of Technology Xidian UniversityGuangzhou 510555China

Flexible and transparent hafnium oxide-based ferroelectric films are attracting widespread attention because of the increasing demand for wearable electronic ***,the ultra-low voltage operation with robust and stable ferroelectricity,which is a prerequisite for portable device applications,has not been realized ***,we report flexible Hf_(0.5)Zr_(0.5)O_(2) ferroelectric films with a saturation voltage of only 1.3/3 V and remanent polarization(2Pr)of 38/60µC·cm^(2).Negligible wake-up effect and superior stability resistance to compressive/tensile stress and high temperature up to 150°C are also *** polarization switching dynamics under bending are investigated based on the switching current measurement,suggesting that the intrinsic switching speeds keep almost constant at different bending *** addition,there is a negative correlation between the activation field and the compressive or tensile stress,which is due to the lowered energy barrier induced by the in-plane strain applied to the[111]-oriented hexagonal *** work sheds light on the application of flexible,stable,and HfO2-based ferroelectric thin films with ultra-low consumption.

关键词： flexible ferroelectrics Hf_(0.5)Zr_(0.5)O_(2) ultra-low voltage operation reliability

Lagrangian mechanics of H-bond vibration

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Lagrangian mechanics of H-bond vibration

Tuning the interfacial reaction environment via pH-dependent and induced ions to understand C–N bonds coupling performance in NO3- integrated CO2 reduction to carbon and nitrogen compounds over dual Cu-based N-doped carbon catalyst

第十二届全国物理力学学术会议

作者： Yong-Li Huang Zeng-Sheng Ma yi-chun zhou Guang-Hui zhou Chang-Qing Sun Xiangtan University

A precise solution to the Lagrangian mechanics of the segmented,flexible,polarizable, and fluctuating "O:H-O" H-bond in water ice with the involvement of the short-ranged real-bond exchange interaction,non-bond van der Waals interaction,and the Coulomb repulsion between the unevenly-bound bonding "-" and nonbonding ":" electron *** to the measured Raman frequencies,the respective force constants are *** is verified that the thermodynamic disparity of the segments and the inter-electron-pair Coulomb repulsion govern the H-bond asymmetric relaxation dynamics and the anomalies of HO.

关键词： soft matter Lagrangian vibration

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Journal of Energy Chemistry 2025年第1期100卷 273-285页

作者： Tianhang zhou Chen Shen Zhenghao Wu Xingying Lan yi Xiao College of Carbon Neutrality Future Technology State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) Institute of Materials Science TU Darmstadt Department of Chemistry Xi'an Jiaotong-Liverpool University Department of Mechanical and Mechatronics Engineering and Waterloo Institute of Nanotechnology University of Waterloo Waterloo

Dual atomic catalysts （DAC）,particularly copper （Cu2）-based nitrogen （N） doped graphene,show great potential to effectively convert CO2and nitrate （NO3-） into important industrial chemicals such as ethylene,glycol,acetamide,and urea through an efficient catalytical process that involves C–C and C–N ***,the origin of the coupling activity remained unclear,which substantially hinders the rational design of Cu-based catalysts for the N-integrated CO2reduction reaction （CO2RR）.To address this challenge,this work performed advanced density functional theory calculations incorporating explicit solvation based on a Cu2-based N-doped carbon (Cu2N6C10) catalyst for *** calculations are aimed to gain insight into the reaction mechanisms for the synthesis of ethylene,acetamide,and urea via coupling in the interfacial reaction *** to the sluggishness of CO2,the formation of a solvation electric layer by anions （F-,Cl-,Br-,and I-） and cations (Na+,Mg2+,K+,and Ca2+) leads to electron transfer towards the Cu *** process significantly accelerates the reduction of *** results reveal that*CO intermediates play a pivotal role in N-integrated ***,the Cu2-based N-doped carbon catalyst examined in this study has demonstrated the most potential for C–N coupling to *** findings reveal that through the process of a condensation reaction between*CO and NH2OH for urea synthesis,*NO3-is reduced to*NH3,and*CO2to*CCO at dual Cu atom *** dual-site reduction facilitates the synthesis of acetamide through a nucleophilic reaction between NH3and the ketene ***,we found that the I-and Mg2+ions,influenced by pH,were highly effective for acetamide and ammonia synthesis,except when F-and Ca2+were ***,the mechanisms of C–N bond formation were investigated via ab-initio molecular dynamics simulations,and we found that adjusting the micro-environment can change the dominant side reaction,shift

关键词： Condensation reactions

Structure and composition-dependent optical properties of(PbxSr1-x)TiO3（x=0.4,0.6） nanotube arrays

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Progress in Natural Science:Materials International 2011年第3期21卷 198-204页

作者： Yan-ping JIANG~(1,2),Xin-gui TANG~(1,2),yi-chun zhou~1,Qiu-xiang LIU~2 1.Key Laboratory of Low Dimensional Materials and Application Technology, Xiangtan University,Xiangtan 411105,China 2.School of Physics and Optoelectronic Engineering,Guangdong University of Technology, Guangzhou 510006,China Key Laboratory of Low Dimensional Materials and Application Technology Xiangtan University Xiangtan 411105 China School of Physics and Optoelectronic Engineering Guangdong University of Technology Guangzhou 510006 China

Lead strontium titanate(PbxSr1-x)TiO3（x=0.4,0.6） nanotubes were synthesized by sol-gel template method via spin *** structures and morphology of the as-prepared samples were characterized by X-ray *** electron microscopy and transmission electron microscopy.X-ray photoelectron spectroscopy was used to determine the chemical composition of the sample and the valence state of *** spectroscopy of the as-prepared(PbxSr1-x)TiO3（x=0.4,0.6） nanotubes at room temperature was also *** results indicate that as-prepared(PbxSr1-x)TiO3（x=0.4,0.6） nanotubes are perfectly crystallized and there is a trend of structure change from PST40 to PST60.A weak peak at 508 cm-1assigned to E（3TO） mode can be seen in the Raman spectrum of(Pb0.6Sr0.4)*** spectra of samples at room temperature reveal three intense emission bands centered at 356,400 nm for(Pb0.4Sr0.6)TiO3and 413,433,451 nm for(Pb0.6Sr0.4)TiO3nanotubes. *** peak positions of the emission band have a significant blue shift as Pb content increases.

关键词： (PbxSr1-x)TiO3 nanotube sol-gel AAO template Raman spectrum photoluminecsence