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Journal of Rare Earths 2024年第10期42卷 1995-2002页

作者： Minakshi Koundal Chhaya Sharma A.K.Singh Department of Applied Science and Engineering Indian Institute of Technology RoorkeeSaharanpur Campus Department of Pulp and Paper Technology Indian institute of Technology Roorkee Saharanpur Campus

Cerium tartrate（CeTar）,produced in this study by precipitating cerium nitrate with potassium sodium tartrate（KNaTar）,was examined as a corrosion *** loss tests show inhibition efficiency of 71.7% with Ce（NO3）3and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl *** inhibition efficiency drops to 28.6% with the fo rmer and remains around 8 7% with the latter inhibitor after six months of *** results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium ***,the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d,i.e.,≈90%.Electrochemical impedance spectroscopy（EIS） performed in these cases shows the following results:（ⅰ） with cerium nitrate,a film of iron and cerium oxide,which on prolonged exposure diminishes,and（ⅱ） with cerium tartrate,the formation of a bimetallic film（Fe-tartrate-Ce） and a mixture of cerium hydroxide and iro n oxide that protects steel for a longer *** inferences are based on the analyses of scanning electron microscopy/energydispersive X-ray analysis（SEM/EDAX）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron（XPS）,and Raman spectroscopy results.

关键词： Cerium nitrate Cerium tartrate Corrosion inhibition Inhibitor film characterization Mild steel Rare earths

Model architecture level privacy leakage in neural networks

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Science China(Information Sciences) 2024年第3期67卷 20-32页

作者： Yan LI Hongyang YAN Teng HUANG Zijie PAN Jiewei LAI Xiaoxue ZHANG Kongyang CHEN Jin LI institute of Artificial Intelligent and Blockchain Guangzhou University Pazhou Lab

Privacy leakage is one of the most critical issues in machine learning and has attracted growing interest for tasks such as demonstrating potential threats in model attacks and creating model *** recent years, numerous studies have revealed various privacy leakage risks(e.g., data reconstruction attack, membership inference attack, backdoor attack, and adversarial attack) and several targeted defense approaches(e.g., data denoising, differential privacy, and data encryption). However, existing solutions generally focus on model parameter levels to disclose(or repair) privacy threats during the model training and/or model interference process, which are rarely applied at the model architecture level. Thus, in this paper, we aim to exploit the potential privacy leakage at the model architecture level through a pioneer study on neural architecture search(NAS) paradigms which serves as a powerful tool to automate a neural network *** investigating the NAS procedure, we discover two attack threats in the model architecture level called the architectural dataset reconstruction attack and the architectural membership inference attack. Our theoretical analysis and experimental evaluation reveal that an attacker may leverage the output architecture of an ongoing NAS paradigm to reconstruct its original training set, or accurately infer the memberships of its training set simply from the model architecture. In this work, we also propose several defense approaches related to these model architecture attacks. We hope our work can highlight the need for greater attention to privacy protection in model architecture levels(e.g., NAS paradigms).

关键词： neural architecture search data reconstruction attack membership inference attack

An application of space-filling curves to improve results of turbulent aerodynamics modeling with convolutional neural networks

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Chinese Journal of Aeronautics 2024年第2期37卷 81-92页

作者： Mikhail PETROV Sofia ZIMINA Moscow institute of Physics&Technology Dolgoprudny 141701Russia

When carrying out calculations for turbulent flow simulation,one inevitably has to face the choice between accuracy and speed of *** order to simultaneously obtain both a computationally efficient and more accurate model,a surrogate model can be built on the basis of some fast special model and knowledge of previous calculations obtained by more accurate base models from various test bases or some results of serial *** objective of this work is to construct a surrogate model which allows to improve the accuracy of turbulent calculations obtained by a special model on unstructured *** this purpose,we use 1D Convolutional Neural Network(CNN)of the encoder-decoder architecture and reduce the problem to a single dimension by applying space-filling *** an approach would have the benefit of being applicable to solutions obtained on unstructured *** this work,a non-local approach is applied where entire flow fields obtained by the special and base models are used as input and ground truth output ***-Allmaras(SA)model and Near-wall Domain Decomposition(NDD)method for SA are taken as the base and special models *** efficiency and accuracy of the obtained surrogate model are demonstrated in a case of supersonic flow over a compression corner with different values for angleαand Reynolds number *** conducted an investigation into interpolation and extrapolation by Re and also into interpolation byα.

关键词： Space-filling curves Convolutional neural network Domain decomposition Turbulent flows Unstructured mesh

Superatom-assembled boranes,carboranes,and low-dimensional boron nanomaterials based on aromatic icosahedral B_(12)and C_(2)B_(10)

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Nano Research 2024年第7期17卷 6734-6740页

作者： Qiao-Qiao Yan Yan-Fang Wei Qiang Chen Yue-Wen Mu Si-Dian Li institute of Molecular Science Shanxi UniversityTaiyuan 030006China

Using the experimentally known aromatic icosahedral superatoms I_(h)B_(12)H_(12)2−and D_(5d)1,12-C_(2)B_(10)H_(12)as building blocks and based on extensive density functional theory calculations,we predict herein a series of core–shell superpolyhedral boranes and carboranes in a bottom-up approach,including the high-symmetry Th B_(12)@B_(152)H_(72)2−(2),C2h C_(2)B_(10)@B_(152)H_(72)(3),D_(3d)B_(12)@B_(144)H_(66)(4),I_(h)B_(12)@C_(24)B_(12)0H_(72)2−(6),and D_(5d)C_(2)B_(10)@C_(24)B_(12)0H_(72)(7).More interestingly,the superatom-assembled linear D2h B_(36)H_(32)^(2−)(8),close-packed planar D_(3d)B_(84)H_(60)^(2−)(10),and nearly close-packed core−shell D_(3d)B_(12)@B144H_(6)6(4)can be extended periodically to form the one-dimensional(1D)α-rhombohedral borane nanowire B_(12)H_(10)(Pmmm)(9),two-dimensional(2D)α-rhombohedral monolayer borophane B_(12)H_(6)(P m1)(11),and the experimentally known three-dimensional(3D)α-rhombohedral boron(R m)(12)which can be viewed as an assembly of the monolayer B_(12)H_(6)(11)staggered in vertical direction,setting up a bottom-up strategy to form low-dimensional boron-based nanomaterials from their borane“seeds”via partial or complete *** bonding analyses indicate that the high stability of these nanostructures originates from the spherical aromaticity of their icosahedral B_(12)or C_(2)B_(10)structural units which possess the universal skeleton electronic configuration of 1S21P61D101F8 following the Wade’s n+1 *** infrared(IR)and Raman spectra of the most-concerned neutral B_(12)@B144H_(6)6(4)and C_(2)B_(10)@C_(24)B_(12)0H_(72)(7)are computationally simulated to facilitate their experimental characterizations.

关键词： superatom-assembling bottom-up approach density functional theory superpolyhedral boranes superpolyhedral carboranes borophanes

Quantum discord and its dynamics for multipartite systems

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Chinese Physics B 2024年第6期33卷 168-175页

作者：罗嘉欣郭琼 College of Sciences Shanghai Institute of TechnologyShanghai 201418China

Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For the bipartite system, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For multiparitite systems, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing does not exist in the even-partite systems.

关键词： quantum discord multipartite systems decoherence channels frozen discord

Exploration of microscopic physical processes of Z-pinch by a modified electrostatic direct implicit particle-in-cell algorithm

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Chinese Physics B 2024年第9期33卷 433-442页

作者： Kaixuan Li Cheng Ning Ye Dong Chuang Xue institute of Applied Physics and Computational Mathematics Beijing 100088China

For investigating efficiently the stagnation kinetic-process of Z-pinch,we develop a novel modified electrostatic implicit particle-in-cell algorithm in radial one-dimension for Z-pinch simulation in which a small-angle cumulative binary collision algorithm is *** our algorithm,the electric field in z-direction is solved by a parallel electrode-plate model,the azimuthal magnetic field is obtained by Ampere’s law,and the term for charged particle gyromotion is approximated by the cross product of the averaged velocity and magnetic *** simulation results of 2 MA deuterium plasma shell Zpinch,the mass-center implosion trajectory agrees generally with that obtained by one-dimensional MHD simulation,and the plasma current also closely aligns with the external *** phase space diagrams and radial-velocity probability distributions of ions and electrons are *** main kinetic characteristic of electron motion is thermal equilibrium and oscillation,which should be oscillated around the ions,while that of ion motion is implosion *** the region of stagnation radius,the radial-velocity probability distribution of ions transits from the non-equilibrium to equilibrium state with the current increasing,while of electrons is basically the equilibrium *** the initial ion density and current peak are not high enough,the ions may not reach their thermal equilibrium state through collisions even in its stagnation phase.

关键词： Z-pinch particle-in-cell ion heating charged particle collisions

Two‑Dimensional Cr_(5)Te_(8)@Graphite Heterostructure for Efficient Electromagnetic Microwave Absorption

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Nano-Micro Letters 2024年第3期16卷 407-422页

作者： Liyuan Qin Ziyang Guo Shuai Zhao Denan Kong Wei Jiang Ruibin Liu Xijuan Lv Jiadong Zhou Qinghai Shu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081People’s Republic of China Advanced Research institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081People’s Republic of China Tangshan Research institute Beijing Institute of TechnologyTangshan 063099People’s Republic of China

Two-dimensional(2D)transition metal chalcogenides(TMCs)hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric ***,overcoming the impedance mismatch at the low loading is still a challenge for TMCs due to the restricted loss pathways caused by their high-density ***,an interface engineering based on the heterostructure of 2D Cr_(5)Te_(8) and graphite is in situ constructed via a one-step chemical vapor deposit to modulate impedance matching and introduce multiple attenuation ***,the Cr_(5)Te_(8)@EG(ECT)heterostructure exhibits a minimum reflection loss of up to−57.6 dB at 15.4 GHz with a thin thickness of only 1.4 mm under a low filling rate of 10%.The density functional theory calculations confirm that the splendid performance of ECT heterostructure primarily derives from charge redistribution at the abundant intimate interfaces,thereby reinforcing interfacial polarization ***,the ECT coating displays a remarkable radar cross section reduction of 31.9 dB m^(2),demonstrating a great radar microwave scattering *** work sheds light on the interfacial coupled stimulus response mechanism of TMC-based heterogeneous structures and provides a feasible strategy to manipulate high-quality TMCs for excellent microwave absorbers.

关键词： Chemical vapor deposition Interface polarization engineering Cr_(5)Te_(8)-graphite heterojunctions Microwave absorption

Spatiotemporal dynamics of city-level WEEE generation from different sources in China

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Frontiers of Engineering Management 2024年第2期11卷 181-193页

作者： Wanjun WANG Yupeng LIU Kuishuang FENG Wei-Qiang CHEN Key Research institute of Yellow River Civilization and Sustainable Development&Collaborative Innovation Center of Yellow River Civilization Henan UniversityKaifeng 475001China Key Laboratory of Urban Environment and health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Department of Geographical Sciences University of MarylandCollege ParkUSA

China stands as one of the leading producers of waste electrical and electronic equipment(WEEE),facing significant challenges in managing the substantial volumes *** existing regulations,the informal treatment of WEEE persists in some areas due to inadequate recycling networks at the city ***,there is a critical need for a detailed geographical mapping of WEEE generation to address improper disposal practices *** study introduces the cMAC–EEEs(city Material Cycles and Manufactured Capital–EEEs)database,providing estimates of WEEE generation across approximately 300 prefecture-level cities from 1978 to *** focuses on five commonly used types of electrical and electronic equipment(refrigerators,air conditioners,washing machines,computers,TVs)originating from three key sources(urban residents,rural residents,enterprises).The findings reveal(1)significant spatial variation in WEEE generation within China,with eastern and central city clusters identified as hotspots,particularly for urban residents and enterprises,while the western region exhibits the highest growth rate in WEEE generation,notably among rural residents.(2)The growth in obsolete computers and air conditioners is prominent,especially in rural areas and among enterprises,whereas the generation of obsolete TVs,washing machines,and refrigerators is leveling off and expected to decrease in some urban areas.(3)Enterprises account for a substantial portion of WEEE generation,though uncertainties exist,necessitating further *** study highlights that less developed regions lack adequate recycling facilities,with specific limitations in refrigerators and air conditioners recycling *** enhance WEEE management,it advocates for increased interregional collaboration and capacity building in less developed ***,the regulation of WEEE from private enterprises requires *** the product level,a greater focus on recycling practices

关键词： WEEE obsolete electrical and electronic equipment urban mining waste management industrial ecology

Mechanism of Ta on the microstructure and properties of Fe-Mn damping alloys

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Tungsten 2024年第4期6卷 767-777页

作者： Gui-Xiang Liu Kun Zhang Chao Han Xiao-Lin Shao Jun Lu Lin Zhang Xiao-Song Jiang Zi-Xuan Wu Liu Yang The Second Sub-institute Nuclear Power Institute of China Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiao tong University School of Engineering and Materials Science Queen Mary University of London institute for Applied Materials (IAM-WK) Karlsruhe Institute of Technology (KIT)

Fe-Mn-Co-xTa alloys（x=0,1,2,3 wt.%） were fabricated using spark plasma sintering to explore the influence of Ta content on the microstructure,mechanical properties,and damping characteristics of Fe-17Mn-3Co damping *** micro structural analysis reveals the dominant presence of γ-austenite,ε-martensite,α'-martensite,and Co3Ta precipitates within the *** increments in Ta content exhibit proportional enhancements in hardness,tensile strength,and fracture elongation of the ***,these improvements in mechanical attributes are closely correlated with the generated second-phase *** the Ta content increases,there is a gradual augmentation in the formation of Co3Ta within the ***,the damping property initially experiences an ascent followed by a subsequent decline with rising Ta *** damping behavior finds its origins in multiple mechanisms,including grain boundary damping stemming from reduced grain size,interfacial damping induced by the generated Co3Ta,and dislocation *** is noteworthy that the emergence of the secondary phase wields a dual impact on damping *** the one hand,the proliferation of the second phase fosters increased interfaces for energy *** the other hand,these interfaces give rise to compressive stresses,constraining interface movement and thus impeding damping property enhancement.

关键词： Damping Fe–Mn–Co Mechanical properties Spark plasma sintering Ta

An artificial neural network based deep collocation method for the solution of transient linear and nonlinear partial differential equations

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1296-1310页

作者： Abhishek MISHRA Cosmin ANITESCU Pattabhi Ramaiah BUDARAPU Sundararajan NATARAJAN Pandu Rang VUNDAVILLI Timon RABCZUK School of Mechanical Sciences Indian Institute of TechnologyBhubaneswar 752050India institute of Structural Mechanics Bauhaus University of WeimarWeimar 99423Germany Department of Mechanical Engineering Indian Institute of Technology MadrasChennai 600036India

A combined deep machine learning(DML)and collocation based approach to solve the partial differential equations using artificial neural networks is *** developed method is applied to solve problems governed by the Sine–Gordon equation(SGE),the scalar wave equation and *** methods are studied:one is a space-time formulation and the other is a semi-discrete method based on an implicit Runge–Kutta(RK)time *** methodology is implemented using the Tensorflow framework and it is tested on several numerical *** on the results,the relative normalized error was observed to be less than 5%in all cases.

关键词： collocation method artificial neural networks deep machine learning Sine-Gordon equation transient wave equation dynamic scalar and elasto-dynamic equation Runge-Kutta method