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Microstructural Evolution and Softening Behavior of Simulated Heat-Affected Zone in 2219 Aluminum Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第12期30卷 1177-1184页

作者： Xin-Jie Di Hui-Juan Xie Cui-Xin Chen cai-yan deng Dong-Po Wang School of Materials Science and Engineering Tianjin University School of Materials Science and Engineering Hebei University of Technology

The effect of peak temperature （Tp） at 200, 300, 400, 500 and 550 ℃ on the microstructural evolution and softening behavior of the simulated heat-affected zone （HAZ） was studied in the 2219-T87 alloy by electron-backscatter diffraction, transmission electron microscopy, X-ray diffraction, micro-hardness and micro-tensile tests. The results showed that the grain size in the HAZs at 200-500 ℃ was comparable, but the number density of the strengthening precipitates （GP zones/θ′） decreased with increasing Tp. At a Tp of 550 ℃, the grain size significantly decreased and the distribution of the misorientation angles corresponded to the MacKenzie distribution. The GP zones/θ′ phase coarsened and translated into θ phases at Tp values in the range of 200-400 ℃. Increasing the Tp to 500 ℃ and above, some θ′ phases translated into θ phases and others dissolved into the α-Al matrix which led to an increase in the solid solution strengthening. The reduction of the number density of the GP zones/θ′ was responsible for the softening behavior.

关键词： 2219 aluminum alloy Peak temperature of thermal cycles Electron-backscatter diffraction(EBSD) Softening behavior Precipitates

Mathematical framework of nonlinear elastic waves propagating in pre-stressed media

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1705-1716页

作者： Jiangcheng cai Mingxi deng College of Aerospace Engineering Chongqing University

Acoustic nonlinearity holds potential as a method for assessing material stress. Analogous to the acoustoelastic effect, where the velocity of elastic waves is influenced by third-order elastic constants, the propagation of nonlinear acoustic waves in pre-stressed materials would be influenced by higher-order elastic constants. Despite this,there has been a notable absence of research exploring this phenomenon. Consequently,this paper aims to establish a theoretical framework for governing the propagation of nonlinear acoustic waves in pre-stressed materials. It delves into the impact of pre-stress on higher-order material parameters, and specifically examines the propagation of onedimensional acoustic waves within the contexts of the uniaxial stress and the biaxial stress. This paper establishes a theoretical foundation for exploring the application of nonlinear ultrasonic techniques to measure pre-stress in materials.

关键词： 74J30 acoustoelastic effect higherorder elastic constant nonlinear elastic wave O343 pre-stress medium

Coordination structure regulation in non-flammable electrolyte enabling high voltage lithium electrochemistry

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Journal of Energy Chemistry 2024年第9期96卷 282-290页

作者： Zhiwen deng Ye Jia yan deng Changhaoyue Xu Xuemei Zhang Qiujie He Jianan Peng Hao Wu Wenlong cai College of Materials Science and Engineering Sichuan UniversityChengdu 610064SichuanChina Engineering Research Center of Alternative Energy Materials and Devices Sichuan UniversityChengdu 610064SichuanChina

High-voltage battery systems bring significant increases in energy density but are also accompanied by fast degradation of electrochemical performance and serious safety ***,Li^(+)coordination structure regulation was conducted to formulate a non-flammable electrolyte,which consists of 1.5 M lithium bis(fluor sulfonyl)imide(LiFSI)in triethyl phosphate and methyl 2,2,2-trifluoromethyl carbonate(FEMC).The renamed TEP-FEMC-FEC(TFF)electrolyte exhibits an FSI^(−)-dominated solvation structure contributed by the weakly-solvating ability of *** generated inorganic-rich interfacial layers are conducive to stabilizing the phase transition of high-voltage cathodes while suppressing the dendritic growth on lithium metal or co-intercalation behavior in graphite *** TFF electrolyte enables LiCoO_(2)||Li batteries to achieve capacity maintenance over 79%after 400 cycles with high-rate of 5 C at an ultra-high voltage of 4.6 V,and an outstanding capacity exceeding 100 mA h g^(−1)even at a super-high current density of 20 ***,the Ah-level LiCoO_(2)||graphite pouch cells also exhibit high capacity retention and satisfactory safety performance even under fast *** work provides a novel research direction for the pursuit of high energy density non-flammable electrolytes.

关键词： Non-flammable Solvation structure High-voltage Lithium batteries

A Real-time Lithological Identification Method based on SMOTE-Tomek and ICSA Optimization

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 518-530页

作者： deng Song PAN Haoyu LI Chaowei yan Xiaopeng WANG Jiangshuai SHI Lin PEI Chunyu cai Meng College of Petroleum Engineering Changzhou UniversityChangzhouJiangsu 213000China

In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on machine learning and mud logging data is studied in this *** method can effectively utilize downhole parameters collected in real-time during drilling,to identify lithology in real-time and provide a reference for optimization of drilling *** the imbalance of lithology samples,the synthetic minority over-sampling technique(SMOTE)and Tomek link were used to balance the sample number of five ***,this paper introduces Tent map,random opposition-based learning and dynamic perceived probability to the original crow search algorithm(CSA),and establishes an improved crow search algorithm(ICSA).In this paper,ICSA is used to optimize the hyperparameter combination of random forest(RF),extremely random trees(ET),extreme gradient boosting(XGB),and light gradient boosting machine(LGBM)*** addition,this study combines the recognition advantages of the four *** accuracy of lithology identification by the weighted average probability model reaches *** study of this paper realizes high-precision real-time lithology identification method,which can provide lithology reference for the drilling process.

关键词： mud logging data real-time lithological identification improved crow search algorithm petroleum geological exploration SMOTE-Tomek

Transition metals for stabilizing lithium metal anode:advances and perspectives

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Tungsten 2024年第1期6卷 212-229页

作者： Si-Cheng Miao Ye Jia Zhi-Wen deng yan deng Ruo-Xuan Chen Xue-Mei Zhang Chang-Haoyue Xu Meng Yao Wen-Long cai Department of Advanced Energy Materials College of Materials Science and EngineeringSichuan UniversityChengdu 610064China

As the capacity of lithium-ion batteries gradually reaches its limit,the high-capacity characteristics of lithium metal batteries(LMBs)make them one of the most promising electrochemical energy storage devices ***,uncontrolled lithium dendrite growth can cause poor cell performance and severe safety issues,seriously slowing down the commercialization of *** metals(TMs)are lithiophilic materials that effectively stabilize lithium metal anode(LMA)and inhibit dendrite ***,the growth of lithium dendrites and the performance of TMs in stabilizing lithium metals are comprehensively discussed in this ***,we elucidated the formation mechanisms of lithium dendrite,and we put forward several strategies to suppress lithium dendrite formation based on the understanding of these ***,the application of TMs and their compounds to stabilize LMA and their corresponding mechanisms are comprehensively ***,further research perspectives of TMs in stabilizing LMA are emphasized in detail.

关键词： Transition metals Lithium metal batteries Lithium dendrite Solid electrolyte interphase Formation mechanism

Scattering of Water Waves by Dual Symmetric Inclined Floating Porous Barriers Using the DBEM

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China Ocean Engineering 2024年第1期38卷 156-168页

作者： WANG Li-xian deng yan-wen YE yang-sha deng Zheng-zhi Key Laboratory of High Performance Ship Technology(Wuhan University of Technology) Ministry of EducationWuhan 430063China School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan 430063China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China Institute of Port Coastal and Offshore EngineeringZhejiang UniversityZhoushan 316021China

The scattering of normally incident water waves by two surface-piercing inclined perforated barriers in water with a uniform finite depth is investigated within the framework of linear water wave *** that thin barriers are zero-thickness,a novel numerical method involving the the coupling of the dual boundary element method(DBEM)with damping layers is *** order to effectively damp out the reflected waves,two damping layers,instead of pseudoboundaries are implemented near the two side boundaries of the computational ***,the modified linearized free surface boundary conditions are formulated and used for solving both the ordinary boundary integral equation as well as the hypersingular boundary integral equation for degenerate *** newly developed numerical method is validated against analytical methods using the matched eigenfunction expansion method for the special case of two vertical barriers or the inclined angle to the vertical being *** influence of the length of the two damping layers has been ***,these findings are also validated against previous results for several *** validation,the numerical results for the reflection coefficient,transmission coefficient and dissipation coefficient are obtained by varying the inclination angle and porosity-effect *** effects of both the inclination angle and the porosity on the amplitudes of wave forces acting on both the front and rear barriers are also *** is found that the effect of the inclination angle mainly shifts the location of the extremal values of the reflection and the transmission ***,a moderate value of the porosity-parameter is quite effective at dissipating wave energy and mitigating the wave loads on dual barriers.

关键词： dual boundary element method inclined perforated floating breakwater reflection coefficient transmission coefficient damping layer

Simulation and fabrication of in vitro microfluidic microelectrode array chip for patterned culture and electrophysiological detection of neurons

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Nanotechnology and Precision Engineering 2024年第2期7卷 1-10页

作者： yan yang Shihong Xu Yu deng Yaoyao Liu Kui Zhang Shiya Lv Longze Sha Qi Xu Xinxia cai Jinping Luo State Key Laboratory of Transducer Technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Medical Molecular Biology Institute of Basic Medical SciencesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100005China

To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural *** chip was designed based on the specific structure of neurons and the requirements for detection and ***-element analysis of the chip’s flow field was conducted using the COMSOL Multiphysics software,and the simulation results show that the liquid within the chip can flow smoothly,ensuring stable flow fields that facilitate the uniform growth of neurons within the microfluidic *** employing MEMS technology in combination with nanomaterial modification techniques,the microfluidic microelectrode array chip was fabricated *** hippocampal neurons were cultured on the chip,forming a well-defined neural *** electrical activity of the detected neurons was recorded,exhibiting a 23.7%increase in amplitude compared to neuronal discharges detected on an open-field microelectrode *** study provides a platform for the precise detection and modulation of patterned neuronal growth in vitro,potentially serving as a novel tool in neuroscience research.

关键词： Microfluidic Microelectrode array In vitro Neural chip

Diffusion of nanochannel-confined knot along a tensioned polymer

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Communications in Theoretical Physics 2024年第4期76卷 158-166页

作者： Guobing cai Yong Li Yuyu Feng Zhouhui deng yanhui Liu College of Physics Guizhou UniversityGuiyang 550025China Kechuang Industrial Development Company Limited Guian New AreaGuiyang 550025China State Key Laboratory of Public Big Data Guizhou UniversityGuiyang 550025China

The knots frequently occur in biopolymer and their diffusion plays an active role in the gene *** this work,Langevin dynamics simulations were carried out to detect the diffusion behaviours of a knot along a tensioned polymer in different spatial *** polymer accommodating a knot was tethered to two macrospheres to block the unravelling of the *** a result,the curves for the diffusion coefficients of the knot with different bending stiffness as a function of the tension in different spatial constraints were *** the space without constraints or with weak constraints,the corresponding curves for the knot with relatively large bending stiffness exhibited two turnover *** the contrary,for the knot with relatively small bending stiffness,the diffusion coefficients were monotonically reduced with increasing ***,in a space with strong constraints,all the curves showed one turnover behaviour regardless of the bending *** turnover behaviours divided the curves into different regimes,and the dominant diffusion mechanisms in the regimes,namely,knot-region breathing,self-reptation,and internal friction,were clearly *** effective friction coefficientsξof the knots with 3_(1),4_(1),5_(1) and 5_(2) types as a function of the knot size N at a fixed tension were well fitted by the relationξ∝*** effective friction coefficients of the knots at relatively large tension f>3 sharply increased with the knot complexity,which is not dependent on the spatial *** contrast,the values of these coefficients at relatively small tension f≤3 were remarkably dependent on the spatial *** work not only provides valuable simulation results to assist the understanding of the diffusion of DNA knot,but also highlights the single-molecule design for the manipulation of DNA knots in future.

关键词： knot langevin dynamics simulations diffusion coefficient self-reptation knot-region breathing internal friction

In situ sulfur-doped mesoporous tungsten oxides for gas sensing toward benzene series

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Chinese Chemical Letters 2024年第7期35卷 502-507页

作者： Yu deng yan Liu Yonghui deng Jinsheng Cheng Yidong Zou Wei Luo State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Department of Chemistry State Key Laboratory of Molecular Engineering of PolymersShanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsiChEMFudan UniversityShanghai 200433China Department of Polymeric Materials School of Materials Science and EngineeringTongji UniversityShanghai 201804China Henry-Fork School of Food Sciences Shaoguan UniversityShaoguan 512005China State Key Lab of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

Benzene series as highly toxic gases have inevitably entered human life and produce great threat to human health and ecological environment,and thus it is distinctly meaningful to monitor benzene series with quickly,real-time and efficient ***,novel sulfur-doped mesoporous WO_(3)materials were synthesized via classical in-situ solvent evaporation induced co-assembly strategy combined with doping engineering,which possessed highly crystallized frameworks,high specific surface area(40.9–63.8 m^(2)/g)and uniform pore size(~18 nm).Benefitting from abundant oxygen vacancy and defects via S-doping,the tailored mesoporous S/m WO_(3)exhibited excellent benzene sensing performance,including high sensitivity(50 ppm vs.48),low detection limit(ca.500 ppb),outstanding selectivity and favorable *** addition,the reduction of band gap resulted from S-doping promotes the carrier migration in the sensing materials and the reaction at the gas–solid sensing *** provides brand-new approach to design sensitive materials with multiple reaction sites.

关键词： Mesoporous materials Benzene series Tungsten oxides Sulfur doping Gas sensor