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Degradation and self-recovery of Polycrystalline Silicon TFT CMOS Inverters Under NBTI Stress

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Chinese Journal of Electronics 2019年第4期28卷 884-888页

作者： GUO Jian YU Zhinong YAN Wei SHI Dawei XUE Jianshe XUE Wei School of Optics and Photonics and Beijing Engineering Research Center of Mixed Reality and Advanced Display Beijing Institute of Technology

Degradation and self-recovery of polycrystalline Silicon(poly-Si) Thin film transistor(TFT) by using complementary metal oxide semiconductor(CMOS)inverter were investigated. Under DC stress, degradation mechanisms were clarified by comparing the Voltage transfer characteristics(VTC) of fresh and stressed inverters. It is determined that Negative bias temperature instability(NBTI) of p-TFT dominates the degradation of the inverter under zero bias DC stress. After removing the stress, the VTC continues to be degraded, because the interface trap-states and the grain boundary trapstates increase due to hydrogen species diffusion. It is found out that the VTC is shifted to its right side severely with negative bias stress of VIN. The NBTI of p-TFT is enhanced and the NBTI of n-TFT also plays a role on the degradation. When removing the negative bias stress, the self-recovery of NBTI of nTFT and the continuing degradation of NBTI of p-TFT become competing mechanisms, together controlling the VTC after-stress behavior. Consequently, the continuing degradation of NBTI of p-TFT is restrained by selfrecovery of NBTI of n-TFT.

关键词： Negative bias temperature instability(NBTI) self-recovery Inverter Polycrystalline silicon Voltage transfer characteristics(VTC)

self-recovery ability of stress-damaged salt rock experiment

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Journal of Coal Science & Engineering(China) 2013年第1期19卷 63-68页

作者： De-yi JIANG Qiao-xian LI Jie CHEN Song REN Chun-he YANG State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing 400044 China Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China

After being compressed to different plastic deformation stages, the salt rock samples with lateral stress damage of 0.2, 0.3, 0.4, and 0.5 were selected. Ultrasonic technology was used to monitor the wave velocity variation law of stress-dam-aged salt rock during the self-recovery experiment under different temperatures to analyze the influence of initial stress damage and temperature during the self-recovery of salt rock. The experiment shows that the change of salt rock axial wave velocity is smaller than that of lateral wave velocity. The sample ultrasonic velocity is positively correlated with the time of self-recovery, and the damage had been recovered to a certain extent. In the first 200 hours of self-recovery stage, the salt rock lateral damage recovers fast, and then the damage remains almost unchanged. The value of lateral stable damage is positively correlated with the value of lateral initial stress damage. With the increase of temperature, the recovery of lateral damage speeds up and the value of stable damage decreases; the axial damage of salt rock almost remains unchanged during the self-recovery experiment.

关键词： salt rock damage self-recovery ultrasonic

Research on Early Fault self-recovery Monitoring of Aero-Engine Rotor System

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Engineering（科研） 2010年第1期2卷 60-64页

作者： Z.S. WANG S.W. MA 不详

In order to increase robustness of the AERS (Aero-engine Rotor System) and to solve the problem of lacking fault samples in fault diagnosis and the difficulty in identifying early weak fault, we proposed a new method that it not only can identify the early fault of AERS but also it can do self-recovery monitoring of fault. Our method is based on the analysis of the early fault features on AERS, and it combined the SVM (Support Vector Machine) with the stochastic resonance theory and the wavelet packet decomposition and fault self-recovery. First, we zoom the early fault feature signals by using the stochastic resonance theory. Second, we extract the feature vectors of early fault using the multi-resolution analysis of the wavelet packet. Third, we input the feature vectors to a fault classifier, which can be used to identify the early fault of AERS and carry out self-recovery monitoring of fault. In this paper, features of early fault on AERS, the zoom of early fault characteristics, the extraction method of early fault characteristics, the construction of multi-fault classifier and way of fault self-recovery monitoring are studied. Results show that our method can effectively identify the early fault of AERS, especially for identifying of fault with small samples, and it can carry on self-recovery monitoring of fault.

关键词： AERS Early Fault Support Vector Machine Classification Identification of Fault self-recovery Monitoring of Fault

Ionic conductive hydrogels toughened by latex particles for strain sensors

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Science China(Technological Sciences) 2021年第4期64卷 827-835页

作者： CHANG JingYu ZHANG ZhiXin JIA Fei GAO GuangHui Polymeric and Soft Materials L aboratory School of Chemical Engineering and Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012China

Conductive hydrogels have attracted tremendous attention due to their excellent softness and stretchability as wearable strain sensing ***,most of hydrogel-based strain sensors suffered from poor self-recoverability and fatigue resistance,resulting in significant decrease of strain sensitivity after ***,a soft and flexible wearable strain sensor is prepared by using an ionic conductive hydrogel with latex particles as physical cross-linking *** dynamic physical cross-linking structure can effectively dissipate energy through disruption and reconstruction of molecular segments,thereby imparting excellent stretchability,self-recoverability and fatigue *** addition,the hydrogel exhibits excellent strain-sensitive resistance changes,which enables it to be assembled as a wearable sensor to monitor human *** a result,the hydrogel strain sensor can provide precise feedback for a wide range of human activities,including large-scale joint bending and tiny ***,the tough ionic conductive hydrogel would be widely applied in electronic skin,medical monitoring and artificial intelligence.

关键词： ionic conductive hydrogel strain sensor self-recovery fatigue resistance

Dual function of a high-contrast hydrophobic-hydrophilic coating for enhanced stability of perovskite solar cells in extremely humid environments

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Nano Research 2017年第11期10卷 3885-3895页

作者： Jin Sun Yoo Gill Sang Han Seongha Lee Min Cheol Kim Mansoo Choi Hyun Suk Jung Jung-Kun Lee School of Advanced Materials Science amp Engineering Sungkyunkwan University Suwon 440-746 Republic of Korea Department of Mechanical Engineering and Materials Science University of Pittsburgh Pittsburgh Pennsylvania 15261 USA Department of Mechanical and Aerospace Engineering Seoul National University Seoul 08826 Republic of Korea

In spite of a continuous increase in their power conversion efficiency （PCE） and an economically viable fabrication process,organic-inorganic perovskite solar cells （PSCs） pose a significant problem when used in practical applications：They show fast degradation of the PCE when exposed to very humid *** this study,the stability of PSCs under very humid conditions is greatly enhanced by coating the surface of the PSC devices with a multi-layer film consisting of ultrahydrophobic and relatively hydrophilic layers.A hydrophobic composite of poly（methyl methacrylate）（PMMA）,polyurethane （PU）,and SiO2 nanoparticles successfully retards the water molecules from very humid ***,the hydrophilic layer with moderately PMMA captures the residual moisture within the perovskite layer;subsequently,the perovskite layer *** dual function of the coating film keeps the PCE of PSCs at 17.3% for 180 min when exposed to over 95% humidity.

关键词： perovskite solar cell stability surface coating ultrahydrophobic self-recovery

Natural Cornstalk Pith as an Effective Energy Absorbing Cellular Material

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Journal of Bionic Engineering 2021年第3期18卷 600-610页

作者： Lilong Zhang Zengqian Liu Da Jiao Jian Zhang Shaogang Wang Hui Zhang Zhefeng Zhang Key Laboratory for Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

The replacement of synthetic foam materials using natural biological ones is of great significance for saving energy/resources and reducing environmental *** we characterized the microstructure and mechanical properties of natural cornstalk pith,which has a large annual output yet lacks an effective exploitation,and evaluated its feasibility for applications as a substitute for synthetic foam *** cornstalk pith was revealed to be a cellular material composed of closed cells elongated along the growth direction of com plant and reinforced by well-aligned vascular bundles penetrating the foam *** compressive behavior is featured by a stable stress plateau which is favorable for energy absorption with its mechanical properties largely dependent on the hydration state and loading *** particular,the initial dimension and mechanical properties of cornstalk pith can be effectively recovered after deformation simply by hydration treatment owing to swelling effect caused by the turgor pressure from *** cornstalk pith demonstrates an outstanding combination of low density and high energy absorption efficiency among various foam materials,specifically with its plateau stress and energy absorption comparable or even superior to those of some typical synthetic foam *** along with the huge resources and good biodegradability make it a promising natural energy absorbing cellular material for replacing synthetic counterparts.

关键词： cornstalk pith energy absorption foam hydration self-recovery

Super-tough and rapidly self-recoverable multi-bond network hydrogels facilitated by 2-ureido-4[1H]-pyrimidone dimers

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Chinese Chemical Letters 2021年第1期32卷 521-524页

作者： Hao Xu Xu-Ming Xie Key Laboratory of Advanced Materials(MOE) Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Multi-bond network(MBN) hydrogels contain hierarchical dynamic bonds with different bond association energy as energy dissipation units,enabling super-tough mechanical *** this work,we copolymerize a protonated 2-ureido-4[1 H]-pyrimidone(UPy)-contained monomer with acrylic acid in HCl *** removing excess HCl,UPy motifs are deprotonated and from dimers,thus generating an UPy-contained MBN *** obtained MBN hydrogels(75 wt% watercontent) exhibit super-tough mechanical properties(0.39 MPa to 2.51 MPa tensile strength),with tremendous amount of energy(1.68 MJ/m^(3) to 11.1 MJ/m^(3)) dissipated by the dissociation of UPy *** introduction of ionic bonds can further improve the mechanical ***,owing to their dynamic nature,both UPy dimers and ionic bonds can re-associate after being dissociated,resulting in excellent self-recovery ability(around 90% recovery efficiency within only 1 h).The excellent self-recovery ability mainly originates from the re-association of UPy dimers based on the high dimerization constant of UPy motifs.

关键词： Multi-bond network Quadruple hydrogen bonding self-recovery Super-tough hydrogel 2-Ureido-4[1H]-pyrimidone dimer

A Study on PC/104 Embedded Automatic Balancing Control System

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Journal of Donghua University(English Edition) 2010年第5期27卷 665-668页

作者：曹晰袁洪芳高金吉 Diagnosis and self-recovery Engineering Research Center Beijing University of Chemical Technology College of Information Science and Technology Beijing University of Chemical Technology

In this paper,an embedded real-time control system for automatic rotor balancing was *** from the modular design,this system can be easily re-constituted or expanded under different working *** special designed hardware resists harsh *** an embedded application,it was very important to save system consumptions on both hardware and software,so the algorithms for unbalance vibration identification and attenuation were deduced,meantime a unified fast algorithm structure was achieved through the geometric *** on this structure,the signal processing algorithm was tested by an open data source,while the control algorithm was simulated using a basic rotor model,and then connected to a hyper gravity machine running online *** result confirms that the unbalancing vibration is effectively restrained.

关键词： real time automatic balancing PC/104 vibration signal processing active control self-recovery

self-recoverable semi-crystalline hydrogels with thermomechanics and shape memory performance

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Science China Materials 2019年第4期62卷 586-596页

作者： Kangjun Zhang Ziguang Zhao Jin Huang Tianyi Zhao Ruochen Fang Mingjie Liu Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education School of Chemistry Beihang University Beijing Advanced Innovation Center for Biomedical Engineering Beihang University International Research Institute for Multidisciplinary Science Beihang University

Stimuli-responsive hydrogels have become one of the most popular artificial soft materials due to their excellent adaption to complex environments. Thermoresponsive hydrogels triggered by temperature change can be efficiently utilized in many applications. However, these thermoresponsive hydrogels mostly cannot recover their mechanical states under large strain during the process. Herein, we utilize the heterogeneous comb-type polymer network with semicrystalline hydrophobic side chains to design self-recovery semi-crystalline hydrogels. Based on hydrophilic/hydrophobic cooperative complementary interaction and heterogeneous polymer network, hydrogels can be endowed with excellent thermosensitive properties and mechanical performance. The hydrogels exhibit high compressive strength(7.57 MPa) and compressive modulus(1.76 MPa) due to the semi-crystalline domains formed by association of the hydrophobic poly(ε-caprolactone) PCL. The melting-crystalline transition of PCL and elastic polymer network provide the hydrogels excellent thermomechanical performance and self-recovery property. Furthermore, the hydrogels exhibit shape memory behavior, which can be realized by simple process and smart surface patterning. With these excellent properties, our hydrogels can be applied in sensors, flexible devices and scaffolds for tissue engineering.

关键词： semi-crystalline hydrogels thermomechanics self-recovery shape memory property