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Glancing incidence x-ray fluorescence spectrometry based on a single-bounce parabolic capillary

Chinese Physics B 2023年第8期32卷 247-250页

作者：邵尚坤李惠泉袁天语孙学鹏华路刘志国孙天希 Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875Chin

Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered *** divergence of the x-ray beam was 0.33 *** this paper,we used this instrumental s... 详细信息

关键词： single-bounce parabolic capillary glancing incident x-ray fluorescence(GIXRF) atomic layer deposition film analysis

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High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu Junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China China Research and Development Academy of Machinery Equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 *** study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic *** the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/*** erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered *** examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration ***,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation ***,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present *** upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or *** to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model

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Synergistic surface restructuring and cation mixing via ultrafast Joule heating enhancing ultrahigh-nickel cathodes for advanced lithium-ion batteries

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Journal of Energy Chemistry 2025年第4期103卷 371-382页

作者： Haoyu Wang Jinyang Dong Meng Wang Yun Lu Hongyun Zhang Jinzhong Liu Yun Liu Na Liu Ning Li Qing Huang Feng Wu Yuefeng Su Lai Chen School of Materials Science and Engineering Beijing Key Laboratory of Environmental Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China Testing Centre of Power Batteries China North Vehicle Research InstituteBeijing 100072China

The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during *** this study,doping-induced surface restructuring in ultrahigh-nickel cathode materials is rapidly facilitated through an ultrafast Joule heating *** functional theory(DFT)calculations,synchrotron X-ray absorption spectroscopy(XAS),and single-particle force test confirmed the establishment of a stable crystal framework and lattice oxygen,which mitigated H2-H3 phase transitions and improved structural ***,the Sc doping process exhibits a pinning effect on the grain boundaries,as shown by scanning transmission electron microscopy(STEM),enhancing Li~+diffusion kinetics and decreasing mechanical strain during *** in situ development of a cation-mixing layer at grain boundaries also creates a robust cathode/electrolyte interphase,effectively reducing interfacial parasitic reactions and transition metal dissolution,as validated by STEM and time-of-flight secondary ion mass spectrometry(TOF-SIMS).These synergistic modifications reduce particle cracking and surface/interface degradation,leading to enhanced rate capability,structural integrity,and thermal ***,the optimized Sc-modified ultrahigh-Ni cathode(Sc-1)exhibits 93.99%capacity retention after 100 cycles at 1 C(25℃)and87.06%capacity retention after 100 cycles at 1 C(50℃),indicating excellent cycling and thermal *** presenting a one-step multifunctional modification approach,this research delivers an extensive analysis of the mechanisms governing the structure,microstructure,and interface properties of nickel-rich layered cathode materials(NCMs).These results underscore the potential of ultrahigh-Ni cathodes as viable candidates for advanced lithium-ion batteries(LIBs)in next-generation electric vehicles(EVs).

关键词： Lithium-ion batteries Ultrahigh-nickel layered cathodes In situ surface doping Cation mixing layer Structure and thermal stability

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Performance analysis of an R290 vapor-injection heat pump system for electric vehicles in cold regions

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science China(Technological sciences) 2024年第12期67卷 3673-3681页

作者： YANG YunChun SHAO WenCong YANG TianYang ZOU HuiMing TIAN ChangQing Technical Institute of Physics and Chemistry Key Laboratory of Cryogenic Science and Technology Chinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

High-performance automotive thermal management systems with environment-friendly refrigerants are essential for achieving carbon peaking and carbon neutrality *** this study,an R290 vapor-injection heat pump system for electric vehicles is developed and experimentally *** effects of refrigerant charge mass,injection pressure,and in-cabin air temperature are analyzed in ambient temperatures from-30℃ to 0℃.The results show that the vapor-injection system can increase the coefficient of performance(COP)and heating capacity by 14.3%and 15.9%at 0℃/20℃(ambient/in-cabin temperature)compared with the basic system,and this increase becomes more significant at-20℃/20℃ with improvements of 32.5%and38.1%,*** a lower ambient temperature of-20℃,increasing refrigerant charge mass contributes to a more pronounced increase in heating capacity than at 0℃,which results from the more significant increase in injection mass *** optimal COP at various injection pressures are 2.07 and 1.63 at 0℃ and-20℃ ambient temperatures,corresponding to the relative injection pressures of 0.60 and 0.57,and the injection flow ratios of 0.23 and 0.29,***-30℃/0℃,a COP of1.69 can be achieved.

关键词： propane vapor injection heating performance improvement automotive thermal management system electric vehicle

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Rational design of graphyne-based dual-atom site catalysts for CO oxidation

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Nano Research 2023年第1期16卷 343-351页

作者： Zhenwei Zhang Liang Zhang Xiaoyang Wang Yuan Feng Xiangwen Liu Wenming Sun Department of Chemistry Beijing Key Laboratory for Optical Materials and Photonic DevicesCapital Normal UniversityBeijing 100048China Linyi Vocational University of Science and Technology(Linyi Institute of Industrial Technology) Linyi 276000China Dassault Systemes(Shanghai)Information Technology Co. Ltd.Shanghai 200120China Institute of Analysis and Testing Beijing Academy of Science and Technology(Beijing Center for Physical and Chemical Analysis)Beijing 100094China TianHe Supercomputing Center of Huaihai Linyi 276000China

There are increasing concerns about the environmental impact of rising atmospheric carbon monoxide concentrations,thus it is necessary to develop new catalysts for efficient CO *** on first-principles calculations,the potential ofγ-graphyne(GY)as substrate for metals in the 4th and 5th periods under single-atom and dual-atoms concentration modes has been systematically *** was found that single-atom Co,Ir,Rh,and Ru could effectively oxidate CO molecules,especially for single ***,proper atoms concentration could boost the CO oxidation activity by supplying more reaction centers,such as Rh^(2)/*** was determined that two Rh atoms in Rh^(2)/GY act different roles in the catalytic reaction:one structural and another *** tests suggest that substituting the structural Rh atom in the center of acetylenic ring by Co or Cu atom is a possible way to maintain the reaction performance while reducing the noble metal *** systemic investigation will help in understanding the fundamental reaction mechanisms on GY-based *** emphasize that properly exposed frontier orbital of functional metal atom is crucial in adsorption configuration as well as entire catalytic *** study constructs a workflow and provides valuable information for rational design of CO oxidation catalysts.

关键词： density functional theory calculations CO oxidation single-atom catalyst graphyne dual-atom site catalyst

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Attack based on data: a novel perspective to attack sensitive points directly

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Cybersecurity 2024年第3期7卷 111-123页

作者： Yuyao Ge Zhongguo Yang Lizhe Chen Yiming Wang Chengyang Li School of Information Science and Technology North China University of TechnologyBeijingChina Bejing Key Laboratory on Integration and Analysis of Large-Scale Stream Data North China University of TechnologyBeijingChina School of Computer Science Peking UniversityBeijingChina

Adversarial attack for time-series classification model is widely explored and many attack methods are *** there is not a method of attack based on the data *** this paper,we innovatively proposed a black-box sparse attack method based on data *** method directly attack the sensitive points in the time-series data accord-ing to statistical features extract from the *** frst,we have validated the transferability of sensitive points among DNNs with different ***,we use the statistical features extract from the dataset and the sensi-tive rate of each point as the training set to train the predictive ***,predicting the sensitive rate of test set by predictive ***,perturbing according to the sensitive *** attack is limited by constraining the LO norm to achieve one-point *** conduct experiments on several datasets to validate the effectiveness of this method.

关键词： Black-box adversarial attack Time series classification Data mining

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Over 200 times current enhancement via buckling triboelectric nanogenerator at ultra-low speed for monitoring the swelling of lithium ion batteries

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science Bulletin 2025年第2期70卷 148-152页

作者： Maoyi Zhang Chaosheng Hu Tongtong Zhang Chris R.Bowen Rui Li YongAn Huang Yewang Su Zhong Lin Wang Ya Yang Beijing Key Laboratory of Micro-Nano Energy and Sensor Center for High-Entropy Energy and SystemsBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 101400China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering University of BathBath BA27AKUK State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Material Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332-0245USA

Sensors deployed within the Internet of Things(Io T)require a stable and continuous electrical energy supply[1].The traditional approach to provide an energy supply relies primarily on battery power,which has specific shortcomings;these include integration difficulties,the need for frequent charging or replacement,and environmental pollution associated with battery production and *** solve the challenge of delivering an energy supply to sensors,researchers have designed self-powered sensors or have produced power for sensors by scavenging mechanical energy from the surrounding *** generators[2],piezoelectric generators[3]and triboelectric nanogenerators(TENGs)[4,5]are common approaches to scavenge mechanical *** have been widely used in the development of self-powered sensors and the supply of electrical energy to sensors due to their high performance,low cost,and wide range of potential materials[6].

关键词： battery buckling swelling

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Estimating energy release performance of oxidizer-activated aluminum fuel particles under ultrafast stimulus

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Defence technology（防务技术） 2023年第5期23卷 92-99页

作者： Ya-ru Li Hui Ren Xin-zhou Wu Hui-xin Wang Xi-long Yu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.

关键词： Aluminum Glycidyl azide polymer Laser Detonation Explosive Ultrafast stimulus

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Least Square Estimation for Multiple Functional Linear Model with Autoregressive Errors

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 84-98页

作者： Meng WANG Ming-liang SHU Jian-jun ZHOU Si-xin WU Min CHEN School of Management University of Science and Technology of ChinaHefei 230026China Academy of Mathematics and System Science Chinese Academy of SciencesBeijing 100190China Yunnan Key Laboratory of Statistical Modeling and Data Analysis Yunnan UniversityKunming 650091China

As an extension of linear regression in functional data analysis, functional linear regression has been studied by many researchers and applied in various fields. However, in many cases, data is collected sequentially over time, for example the financial series, so it is necessary to consider the autocorrelated structure of errors in functional regression background. To this end, this paper considers a multiple functional linear model with autoregressive errors. Based on the functional principal component analysis, we apply the least square procedure to estimate the functional coefficients and autoregression coefficients. Under some regular conditions, we establish the asymptotic properties of the proposed estimators. A simulation study is conducted to investigate the finite sample performance of our estimators. A real example on China's weather data is applied to illustrate the validity of our model.

关键词： multiple functional linear model autoregressive errors principal component analysis consistency

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Quality assessment of friction-stir-welded aluminum alloy welds via three-dimensional force signals

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Advances in Manufacturing 2024年第1期12卷 61-75页

作者： Ji-Hong Dong Yi-Ming Huang Jia-Lei Zhu Wei Guan Xu-Kai Ren Huan-Wei Yu Lei Cui Beijing Institute of Petrochemical Technology Beijing102617People’s Republic of China Beijing Academy of Safety Engineering and Technology Beijing102617People’s Republic of China AVIC Manufacturing Technology Institute Beijing100024People’s Republic of China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300350People’s Republic of China Shaoxing Special Equipment Testing Institute Shaoxing Key Laboratory of Special Equipment Intelligent Testing and EvaluationShaoxing312071ZhejiangPeople’s Republic of China

An online detection technology must be developed for realizing the real-time control of friction stir *** this study,the three-dimensional force exerted on a material during friction stir welding was collected synchronously and the relationship between the forces and welding quality was *** results indicated that the fluctuation period of the traverse force was equal to that of the lateral force during the stable welding *** phase difference between two horizontal forces wasπ/*** values of the horizontal forces increased with welding speed,whereas their amplitudes remained the *** proposed force model showed that the traverse and lateral forces conformed to an elliptical curve,and this result was consistent with the behavior of the measured *** variational mode decomposition was used to process the plunge *** intrinsic mode function that represented the real fluctuation in the plunge force varied at the same frequency as the spindle rotational *** tunnel defects occurred,the fluctuation period features were consistent with those obtained during normal welding,whereas the ratio parameter defined in this study increased significantly.

关键词： Friction stir welding(FSW) Three-dimensional force model Variational mode decomposition Tunnel defect

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