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nanoindentation Characterization of Creep-fatigue Interaction on Local Creep Behavior of P92 Steel Welded Joint

Chinese Journal of mechanical Engineering 2021年第6期34卷 85-97页

作者： Yuxuan Song Yi Ma Zhouxin Pan Yuebing Li Taihua Zhang Zengliang Gao institute of Process Equipment and Control Engineering College of Mechanical EngineeringZhejiang University of TechnologyHangzhou 310014China institute of micro/nano‑mechanical testing technology&application College of Mechanical EngineeringZhejiang University of TechnologyHangzhou 310014China institute of Solid Mechanics Beihang UniversityBeijing 100000China Engineering Research Center of Process Equipment and Re‑manufacturing Ministry of EducationHangzhou 310014China

In modern fossil and nuclear power plants,the components are subjected to creep,fatigue,and creep-fatigue(CF)due to frequent start-up and shut-down operations at high *** CF interaction on the in-service P92 steel welded joint was investigated by strain-controlled CF tests with different dwell times of 30,120,300,600 and 900 s at 650℃.Based on the observations of the fracture surface by scanning electron microscope(SEM),the character-istic microstructure of fatigue-induced damage was found for the CF specimens with short dwell times(30 and 120 s).The hardness,elastic modulus and creep deformation near the fracture edges of four typical CF specimens with 30,120,600 and 900 s dwell times were measured by *** to specimens with post-weld heat treatment(PWHT),lower hardness and creep strength were found for all CF *** addition,significant reduc-tions in hardness,elastic modulus,and creep strength were measured near the fracture edges for the CF specimens with short dwell times compared to the PWHT *** to PWHT specimens(0.007),the increased strain rate sensitivities(SRS)of 0.010 to 0.17 were estimated from secondary *** increased values of SRS indicate that the room temperature creeps behavior is strongly affected by the decrease in dislocation density after the CF tests.

关键词： P92 steel Welded joint Creep-fatigue interaction nanoindentation Creep behavior

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Selective triggering of phase change in dielectrics by femtosecond pulse trains based on electron dynamics control

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Chinese Physics B 2013年第4期22卷 334-337页

作者：徐传彩姜澜冷妮刘鹏军 Laser micro/nano-Fabrication Laboratory School of Mechanical Engineering Beijing Institute of Technology

In this study we experimentally reveal that the phase change mechanism can be selectively triggered by shaping femtosecond pulse trains based on electron dynamics control （EDC）, including manipulation of excitations, ionizations, densities, and temperatures of electrons. By designing the pulse energy distribution to adjust the absorptions, excitations, ionizations, and recombinations of electrons, the dominant phase change mechanism experiences transition from nonthermal to thermal process. This phenomenon is observed in quadruple, triple, and double pulses per train ablation of fused silica separately. This opens up possibilities for controlling phase change mechanisms by EDC, which is of great significance in laser processing of dielectrics and fabrication of integrated nano- and micro-optical devices.

关键词： phase change electron dynamics pulse shaping

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A cubic triboelectric generator as a self-powered orientation sensor

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Science China(Technological Sciences) 2015年第5期58卷 842-847页

作者： QIU GuoLin LIU Wen HAN MengDi CHENG XiaoLiang MENG Bo SMITHA Ankanahalli Shankaregowda ZHAO JiangMing ZHANG HaiXia Science and technology on micro/nano Fabrication Laboratory Institute of Microelectronics Peking University School of mechanical Engineering Zhengzhou University

Recently, triboelectric generator(TEG) has attracted a lot of attention due to its high output voltage and low-cost fabrication process. Here, a novel cubic TEG box is designed, which has separated electrodes on different surfaces. Thanks to the specially designed structure, it can scavenge vibration energy from all directions. Firstly the device is investigated through finite element method(FEM) simulation. Then the device is evaluated by experiments. The measuremental results show that this device can generate an amount of 25 n C charge during once shake by charging a 10 n F capacitor. Besides, an output voltage about 100 V is obtained, which is able to directly light up several light-emitting diodes(LEDs) simultaneously. At last, the device is utilized as a self-powered orientation sensor, which shows explicit directivity. This work extends the applications of TEG for ambient vibration energy harvesting techniques and the self-powered orientation sensor.

关键词： cubic powered generator fabrication utilized outer capacitor directions separated charges

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Electrophoretic Carbon nanotube Field Emission Layer for Plasma Display Panels

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nano-micro Letters 2012年第4期4卷 247-252页

作者： Qifa Liu Zhuoqing Yang Yan Wang Guifu Ding National Key Laboratory of Science and technology on nano/micro Fabrication technology Research Institute of Micro/Nano Science and Technology Shanghai Jiao Tong University

A carbon-nanotube(CNT) electrophoretic deposition(EPD) process has been developed to prepare a field emission layer in plasma display panels(PDP) for discharge voltage reduction. The CNT layer as a source of discharge priming electrons has been fabricated on the PDP front panel. The balling grinding,mix-acid treatment and EPD parameters have been investigated in order to obtain good uniformity and excellent field emission capability of CNT layer, in order to meet the specifications of CNTs in PDP cell. The measured turn-on field was around 1.1 V/μm in the field emission testing while the minimum sustaining voltage was decreased by 30~40 V with the use of CNT layer in the discharge testing.

关键词： EPD Field emission CNT PDP Sustaining voltage

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Surface micro/nanostructure evolution of Au-Ag alloy nanoplates： Synthesis, simulation, plasmonic photothermal and surface-enhanced Raman scattering applications

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nano Research 2016年第3期9卷 876-885页

作者： Hongmei Qian Meng Xu Xiaowei Li Muwei Ji Lei Cheng Anwer Shoaib Jiajia Liu Lan Jiang Hesun Zhu Jiatao Zhang ing 100081 China Laser micro/nano-Fabrication Laboratory School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China

This study reports the controllable surface roughening of Au-Ag alloy nanoplates via the galvanic replacement reaction between single-crystalline triangular Ag nanoplates and HAuC14 in an aqueous medium. With a combination of experimental evidence and finite element method （FEM） simulations, improved electromagnetic field （E-field） enhancement around the surface-roughened Au- Ag nanoplates and tunable light absorption in the near-infrared （NIR） region （-800-1,400 nm） are achieved by the synergistic effects of the localized surface plasmon resonance （LSPR） from the maintained triangular shape, the controllable Au-Ag alloy composition, and the increased surface roughness. The NIR light extinction enables an active photothermal effect as well as a high photothermal conversion efficiency （78.5%）. The well-maintained triangular shape, surface- roughened evolutions of both micro- and nanostructures, and tunable NIR surface plasmon resonance effect enable potential applications of the Au-Ag alloy nanoplates in surface-enhanced Raman spectroscopic detection of biomolecules through 785-nm laser excitation.

关键词： Au-Ag alloy nanoplates surface roughening finite element method(FEM) simulation photothermal surface enhanced Ramanscattering (SERS)

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Enhancement of light extraction efficiency in OLED with two-dimensional photonic crystal slabs

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Chinese Optics Letters 2006年第6期4卷 353-356页

作者：闫荣金王庆康 institute of micro and nano-Science and technology National Key Laboratory of nano/micro Fabrication technology Shanghai Jiao Tong University

Light extraction efficiency of organic light emitting diode （OLED） based on various photonic crystal slab （PCS） structures was studied. By using the finite-difference time-domain （FDTD） method, we investigated the effect of several parameters, including filling factor and lattice constant, on the enhancement of light extraction efficiency of three basic PCSs, and got the most effective one. Two novel designs of ＂interlaced＂ and ＂double-interlaced＂ PCS structures based on the most effective basic PCS structure were introduced, and the ＂interlaced＂ one was proved to be even more efficient than its prototype. Large enhancement of light extraction efficiency resulted from the coupling to leaky modes in the expended light cone of a band structure, the diffraction in the space between columns, as well as the strong scattering at indium-tinoxide/glass interfaces.

关键词： Enhancement of light extraction efficiency in OLED with two-dimensional photonic crystal slabs OLED

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An electrical-coupling-suppressing MEMS gyroscope with feed-forward coupling compensation and scalable fuzzy control

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Science China(Information Sciences) 2017年第4期60卷 180-190页

作者： Chunhua HE Jimeng ZHANG Qiancheng ZHAO Qinwen HUANG Zhenchuan YANG Dacheng ZHANG Guizhen YAN National Key Laboratory of Science and technology on micro/nano Fabrication Institute of Microelectronics Science and technology on Reliability Physics and application of Electronic Component Laboratory No.5 Electronics Research Institute of the Ministry of Industry and Information Technology

This paper proposes a novel electrical coupling suppressing and drive closed loop control method for a MEMS gyroscope with feed-forward coupling compensation(FCC) and scalable fuzzy control. Theoretical analysis of the novel method is described in detail, and it is very simple to realize. Experimental results demonstrate that the electrical anti-resonant peaks located at the amplitude-frequency and phase-frequency responses are both eliminated by FCC control, and the height of the amplitude resonant peak increases more than 24 d B over 1800 Hz span. In addition, the overshoot of the transient response with scalable fuzzy control is smaller than 5%, and the settling time is less than 15 ms. The stabilities of the resonant amplitude and phase of the drive-mode velocity with scalable fuzzy control are about 15 ppm and 11 ppm, respectively. The scale factor of the gyroscope is measured to be 33.98 m V/deg/s with nonlinearity about 0.08%. Furthermore, the bias instability of the gyroscope with wavelet analysis is improved to be about 6.3 deg/h from 25.2 deg/h of the gyroscope without wavelet analysis.

关键词： MEMS gyroscope electrical coupling suppressing anti-resonance feed-forward coupling compen sation scalable fuzzy control

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Fabrication of ridged microstructures on FeCrAl porous metal support enhanced catalyst coating performance by UV-laser micromilling

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Science China Technological Sciences 2024年第12期67卷 3877-3889页

作者： LI XinYing GAO Chao CHEN Ying ZHOU Wei Pen-Tung Sah institute of micro-nano Science and technology Xiamen University

The enhancement of catalyst coating performance is significantly influenced by the microstructures on the surface of catalyst supports. This study explores the fabrication of ridged microstructures on the surface of the FeCrAl porous metal, which serves as electrified catalyst support for methanol steam reforming(MSR), using ultraviolet(UV)-laser micromilling technology. The formation mechanism of these ridged microstructures was thoroughly analyzed. Surface morphology under different laser processing parameters was examined using scanning electron microscopy(SEM). Surface oxygen context and roughness were measured with energy-dispersive X-ray spectroscopy and a 3D laser confocal microscope, respectively. Contact angles of the microstructures under different laser conditions were observed using a contact angle measuring instrument. After laser processing, the porous metal supports were loaded with catalysts, and the performance of these catalyst coatings was tested using ultrasonic vibration tests. SEM observations highlighted improved uniformity of the catalyst coating on the support after laser processing. Experimental results showed that supports processed with UV lasers exhibited better hydrophilicity, with contact angles mostly less than 90°, facilitating better diffusion and adhesion of the catalyst solution. Optimal catalyst coating performance on FeCrAl porous metal support with ridge microstructure surface was achieved with laser processing parameters set at200 mm/s speed, 40 kHz frequency, and 5 scans. The optimal microstructure surface demonstrated a load mass of approximately0.5 g and a catalyst coating strength of 87.72%. This represents approximately 17 times and 10 times the performance of unprocessed surfaces, respectively, after 8 min of ultrasonic vibration.

关键词： ultraviolet-laser micromilling ridged microstructure porous metal support catalyst coating hydrogen energy

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An Enhanced Lung Cancer Detection Approach Using Dual-Model Deep Learning Technique

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 835-867页

作者： Sumaia Mohamed Elhassan Saad Mohamed Darwish Saleh Mesbah Elkaffas Department of Information technology Institute of Graduate Studies and ResearchAlexandria UniversityAlexandria21526Egypt College of Computing and Information technology Arab Academy for ScienceTechnology and Maritime TransportAlexandriaP.O.Box 1029Egypt

Lung cancer continues to be a leading cause of cancer-related deaths worldwide,emphasizing the critical need for improved diagnostic *** detection of lung tumors significantly increases the chances of successful treatment and ***,current diagnostic methods often fail to detect tumors at an early stage or to accurately pinpoint their location within the lung ***-model deep learning technologies for lung cancer detection,while beneficial,cannot capture the full range of features present in medical imaging data,leading to incomplete or inaccurate ***,it may not be robust enough to handle the wide variability in medical images due to different imaging conditions,patient anatomy,and tumor *** overcome these disadvantages,dual-model or multi-model approaches can be *** research focuses on enhancing the detection of lung cancer by utilizing a combination of two learning models:a Convolutional Neural Network(CNN)for categorization and the You Only Look Once(YOLOv8)architecture for real-time identification and pinpointing of *** automatically learn to extract hierarchical features from raw image data,capturing patterns such as edges,textures,and complex structures that are crucial for identifying lung ***8 incorporates multiscale feature extraction,enabling the detection of tumors of varying sizes and scales within a single *** is particularly beneficial for identifying small or irregularly shaped tumors that may be challenging to ***,through the utilization of cutting-edge data augmentation methods,such as Deep Convolutional Generative Adversarial Networks(DCGAN),the suggested approach can handle the issue of limited data and boost the models’ability to learn from diverse and comprehensive *** combined method not only improved accuracy and localization but also ensured efficient real-time processing,which is crucial for practical clinical applicati

关键词： Lung cancer detection dual-model deep learning technique data augmentation CNN YOLOv8

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Brain region-specific roles of brain-derived neurotrophic factor in social stress-induced depressive-like behavior

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Neural Regeneration Research 2025年第1期20卷 159-173页

作者： Man Han Deyang Zeng Wei Tan Xingxing Chen Shuyuan Bai Qiong Wu Yushan Chen Zhen Wei Yufei Mei Yan Zeng Brain Science and Advanced technology institute Wuhan University of Science and TechnologyWuhanHubei ProvinceChina Geriatric Hospital Affiliated to Wuhan University of Science and technology WuhanHubei ProvinceChina School of Public Health Wuhan University of Science and TechnologyWuhanHubei ProvinceChina

Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral *** studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and *** how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress *** this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of *** focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine *** determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic ***,BDNF might be a biological indicator regulating stress-related processes in various brain regions.

关键词： amygdala chronic mild stress chronic social defeat stress corticolimbic system depression hippocampus medial prefrontal cortex nucleus accumbens social stress models ventral tegmental area

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