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Mechanical responses and crystal plasticity model of CoCrNi medium-entropy alloy under ramp wave compression

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Matter and Radiation at Extremes 2024年第5期9卷 93-108页

作者： Jinlei Dong Xuping Zhang Guiji Wang Xianqian Wu Binqiang Luo Xuemiao Chen Fuli Tan Jianheng Zhao Chengwei Sun institute of Fluid physics China Academy of Engineering PhysicsMianyang 621999China institute of Mechanics Chinese Academy of SciencesBeijing 100190China institute of Applied Electronics China Academy of Engineering PhysicsMianyang 621999China

It is of substantial scientific significance and practical value to reveal and understand the multiscale mechanical properties and intrinsic mechanisms of medium-entropy alloys(MEAs)under high strain rates and *** this study,the mechanical responses and deformation mechanisms of an equiatomic CoCrNi MEA are investigated utilizing magnetically driven ramp wave compression(RWC)with a strain rate of 105 s^(−1).The CoCrNi MEA demonstrates excellent dynamic mechanical responses and yield strength under RWC compared with other advanced *** characterizations reveal that grain refinement and abundant micromechanisms,including dislocation slip,stacking faults,nanotwin network,and Lomer–Cottrell locks,collectively contribute to its excellent performance during ***,dense deformation twins and shear bands intersect,forming a weave-like microstructure that can disperse deformation and enhance *** the basis of these observations,we develop a modified crystal plasticity model with coupled dislocation and twinning mechanisms,providing a relatively accurate quantitative description of the multiscale behavior under *** results of simulations indicate that the activation of multilevel microstructures in CoCrNi MEA is primarily attributable to stress inhomogeneities and localized strain during *** research offers valuable insights into the dynamic mechanical responses of CoCrNi MEA,positioning it as a promising material for use under extreme dynamic conditions.

关键词： deformation alloy microstructure

Research on the influences of motion characteristics of jetting projectile charge under water

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Defence Technology（防务技术） 2024年第3期33卷 411-425页

作者： Xing Chen Yong-gang Lu institute of Systems engineering China Academy of Engineering PhysicsMianyang 621900SichuanChina

Shaped charge warhead is important for enhancing the damage performance of underwater *** paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of liner parameters(wall thickness,material),charge aspect ratio,and stand-off distance on the movement characteristics of JPC in *** findings reveal that the head diameter of the JPC increases and experiences significant erosion after entering the water,the effective length of the JPC in water undergoes two distinct phases:a growth phase and a decrease phase,with the velocity of the JPC decaying *** the liner thickness,stand-off distance and the charge aspect ratio can improve the erosion resistance and the velocity retention capacity of the *** optimal ranges for liner thickness and stand-off distance are 0.0363D_(k) to 0.0545D_(k)(D_(k) is the charge diameter),the stand-off distance should be within 1.0D_(k).After the charge aspect ratio higher than 1.25,the charge structure exerts minimal influence the movement characteristics of the JPC in *** density plays a crucial role in the velocity decay pattern of the JPC during *** with higher densities exhibit superior velocity retention capabilities in water,with the velocity decay pattern converging if the densities are ***,copper,tantalum and tungsten liners are deemed appropriate for underwater shaped charge ***,the results will provide an important reference for the design of underwater shaped charge warhead.

关键词： JPC Movement characteristics Underwater penetration Numerical simulation

Direct visualization of laser-driven dynamic fragmentation in tin by in situ x-ray diffraction

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Matter and Radiation at Extremes 2024年第5期9卷 109-114页

作者： Jing Yang Xinxin Wang Liang Xu Qiannan Wang Yi Sun Jiangtao Li Lin Zhang Yinghua Li Yuying Yu Pei Wang Qiang Wu Jianbo Hu Laboratory for Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China Laboratory of Computational physics Institute of Applied Physics and Computational MathematicsBeijing 100094China

We present a novel method for investigating laser-driven dynamic fragmentation in tin using in situ X-ray *** experimental results demonstrate the feasibility of the method for simultaneously identifying the phase and temperature of fragments through analysis of the diffraction ***,we observe a deviation from the widely accepted isentropic release assumption,with the temperature of the fragments being found to be more than 100 K higher than expected,owing to the release of plastic work during dynamic *** findings are further verified through extensive large-scale molecular dynamics simulations,in which strain energies are found to be transferred into thermal energies during the nucleation and growth of voids,leading to an increase in *** findings thus provide crucial insights into the impact-driven dynamic fragmentation phenomenon and reveal the significant influence of plastic work on material response during shock release.

关键词： dynamic release diffraction

Prediction of impurity spectrum function by deep learning algorithm

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Chinese physics B 2024年第5期33卷 52-63页

作者：刘婷韩榕生陈亮 School of Mathematics and physics North China Electric Power UniversityBeijing 102206China institute of Condensed Matter physics North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of physics and Energy Technology North China Electric Power UniversityBaoding 071003China

By using the numerical renormalization group(NRG)method,we construct a large dataset with about one million spectral functions of the Anderson quantum impurity *** dataset contains the density of states(DOS)of the host material,the strength of Coulomb interaction between on-site electrons(U),and the hybridization between the host material and the impurity site(Γ).The continued DOS and spectral functions are stored with Chebyshev coefficients and wavelet functions,*** this dataset,we build seven different machine learning networks to predict the spectral function from the input data,DOS,U,andΓ.Three different evaluation indexes,mean absolute error(MAE),relative error(RE)and root mean square error(RMSE),are used to analyze the prediction abilities of different network *** analysis shows that,for the two kinds of widely used recurrent neural networks(RNNs),gate recurrent unit(GRU)has better performance than the long short term memory(LSTM)network.A combination of bidirectional GRU(BiGRU)and GRU has the best performance among GRU,BiGRU,LSTM,and *** MAE peak of BiGRU+GRU reaches *** have also tested a one-dimensional convolutional neural network(1DCNN)with 20 hidden layers and a residual neural network(ResNet),we find that the 1DCNN has almost the same performance of the BiGRU+GRU network for the original dataset,while the robustness testing seems to be a little weak than BiGRU+GRU when we test all these models on two other independent *** ResNet has the worst performance among all the seven network *** datasets presented in this paper,including the large data set of the spectral function of Anderson quantum impurity model,are openly available at https://***/10.57760/sciencedb.j00113.00192.

关键词： machine learning Anderson impurity model spectral function

Gas sensor array based on carbon-based thin-film transistor for selective detection of indoor harmful gases

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Rare Metals 2024年第9期43卷 4401-4411页

作者： Can Liu Yu Sun Jia-Yi Guo Xiu-Lei Li Lu Tao Jin-Yong Hu Jue-Xian Cao Ping-Hua Tang Yong Zhang School of electrical and Information engineering Hunan Institute of Engineering physics and Optoelectronics&Hunan institute of Advanced Sensing and Information Technology Xiangtan University

The identification of indoor harmful gases is imperative due to their significant threats to human health and *** achieve accurate identification,an effective strategy of constructing a sensor array combined with the pattern recognition algorithm is ***-based thin-film transistors are selected as the sensor array unit,with semiconductor carbon nanotubes （CNTs） within the TFT channels modified with different metals （Au,Cu and Ti） for selective responses to NH3,H2S and HCHO,*** accurate gas species identification,an identification mode that combines linear discriminant analysis algorithms and logistic regression classifier is *** test results demonstrate that by preprocessing the sensor array’s sensing data with the LDA algorithm and subsequently employing the LR classifier for identification,a 100% recognition rate can be achieved for three target gases （NH3,H2S and HCHO）.This work provides significant guidance for future applications of chip-level gas sensors in the realms of the Internet of Things and Artificial Intelligence.

关键词： Carbon-based thin-film transistors Gas sensor arrays Linear discriminant analysis Multi-gas detection Semiconductor carbon nanotubes

Research on the IL-Bagging-DHKELM Short-Term Wind Power Prediction Algorithm Based on Error AP Clustering Analysis

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Computers, Materials & Continua 2024年第6期79卷 5017-5030页

作者： Jing Gao Mingxuan Ji Hongjiang Wang Zhongxiao Du School of electric Power Shenyang Institute of EngineeringShenyang100083China

With the continuous advancement of China’s“peak carbon dioxide emissions and Carbon Neutrality”process,the proportion of wind power is *** the current research,aiming at the problem that the forecasting model is outdated due to the continuous updating of wind power data,a short-term wind power forecasting algorithm based on Incremental Learning-Bagging Deep Hybrid Kernel Extreme Learning Machine(IL-Bagging-DHKELM)error affinity propagation cluster analysis is *** algorithm effectively combines deep hybrid kernel extreme learning machine(DHKELM)with incremental learning(IL).Firstly,an initial wind power prediction model is trained using the Bagging-DHKELM ***,Euclidean morphological distance affinity propagation AP clustering algorithm is used to cluster and analyze the prediction error of wind power obtained from the initial training ***,the correlation between wind power prediction errors and Numerical Weather Prediction(NWP)data is introduced as incremental updates to the initial wind power prediction *** the incremental learning process,multiple error performance indicators are used to measure the overall model performance,thereby enabling incremental updates of wind power *** examples show the method proposed in this article reduces the root mean square error of the initial model by 1.9 percentage points,indicating that this method can be better adapted to the current scenario of the continuous increase in wind power penetration *** accuracy and precision of wind power generation prediction are effectively improved through the method.

关键词： Short-term wind power prediction deep hybrid kernel extreme learning machine incremental learning error clustering

Significantly enhanced thermal stability of HMX by phase-transition lysozyme coating

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Defence Technology（防务技术） 2024年第5期35卷 60-68页

作者： Jiahui Liu Congmei Lin Jianhu Zhang Chengcheng Zeng Zhijian Yang Fude Nie institute of Chemical Materials China Academy of Engineering Physics(CAEP)Mianyang 621900China Graduate School China Academy of Engineering Physics(CAEP)Mianyang 621900China

A new robust bio-inspired route by using lysozyme aqueous solution for surface modification on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)was described in this *** crystals were coated by in situ phase transition of lysozyme(PTL)*** HMX decorated by PTL was characterized by SEM,XRD,FTIR and XPS,demonstrating a dense core-shell coating *** coverage of lysozyme on HMX crystal was calculated by the ratio of sulfur *** surface coverage increased from 60.5% to 93.5% when the content of PTL was changed from 0.5 wt% to 2.0 wt%,indicating efficient *** thermal stability of HMX was investigated by in situ XRD and *** thermal phase transition temperature of HMX(β to δ phase)was delayed by 42℃ with 2.0 wt% PTL coating,which prevented HMX from thermal damage and sensitivity by the effect of PTL *** heating at 215℃,large cracks appeared in the naked HMX crystal,while the PTL coated HMX still maintained intact,with the impact energy of HMX dropped dramatically from 5 J to 2 ***,the impact energy of HMX with 1.0 wt% and 2.0 wt% coating content(HMX@PTL-1.0 and HMX@PTL-2.0)was unchanged(5 J).Present results potentially enable large-scale fabrication of polymorphic energetic materials with outstanding thermal stability by novel lysozyme coating.

关键词： HMX Lysozyme Phase transition Thermal stability Sensitivity

A polarized^(3)He system based on metastability-exchange optical pumping

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 72-81页

作者： Yuting Wang Liangyong Wu Kaiyuan Zhang Mei Peng Siyu Chen Haiyang Yan State Key Laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China institute of Nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key Laboratory of Nuclear physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Key Laboratory of Neutron physics Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyang 621900China

Hyperpolarized^(3)He nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,we report on the design and implementation of a^(3)He polarization system at the China Mianyang Research Reactor(CMRR),utilizing the metastabilityexchange optical pumping(MEOP)*** employed a Merritt coil system consisting of four square coils to furnish a uniform holding *** deployed a 2 W fiber laser to pump the metastable^(3)He atoms and conducted free induction decay(FID)detection of the polarized^(3)He nuclei using both pickup coil and optical *** the optical method,we used a50 m W linearly polarized distributed Bragg reflector(DBR)laser as the *** applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state^(3)*** have developed cell fabrication capabilities at the CMRR,and cells at various pressures ranging from 100 to 1000 Pa have been fabricated and *** a typical borosilicate cell with 100 Pa pressure,the absolute polarization is measured as Pn≈70%,and the transverse relaxation time is estimated as T2≈0.5 ***,we constructed a few aluminosilicate cells,each carefully filled with pure^(3)He at a pressure of 100 ***,we conducted a comprehensive evaluation of their performance in the context of MEOP.

关键词： metastability exchange optical pumping polarized^(3)He magnetic resonance

Reflection behavior of insensitive explosive detonation propagating around a cylinder

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Acta Mechanica Sinica 2024年第7期40卷 55-65页

作者： Zixuan Zhang Yuan Wang Xiaomian Hu Haitao Chen institute of Applied physics and Computational Mathematics Beijing 100094China Graduate School of China Academy of engineering physics Beijing 100088China

Insensitive explosive detonation has wide applications in compressing and driving inert materials,and thereby the interaction between detonation and inert materials has received more *** this paper,a two-dimensional numerical simulation based on the Euler multiphase flow framework is used to investigate the reflection behavior of the insensitive explosive detonation propagating around a *** results show that there is a critical incident angle,defined as transition angle for detonation propagating around the cylinder,below which the regular reflection(RR)on the cylinder surface is *** the incident angle is greater than the transition angle,RR changes to Mach *** transition angle is larger than that obtained by polar curve theory and the change of incident angle is used to interpret above *** addition,the influence of cylindrical radius and detonation reaction zone width on the reflection behavior is *** the cylindrical radius increases,the height of Mach stem increases while the transition angle decreases and gradually approaches the value in pole curve *** Neumann reflection is observed when the reaction zone width is relatively *** is because the energy release rate in the reaction zone is high for small reaction zone width,resulting in the formation of a series of compression waves near the cylindrical interface.

关键词： Insensitive explosive detonation Cylindrical inert material Reflection behavior