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DCVAE-adv:A Universal Adversarial Example Generation Method for White and Black Box Attacks

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Tsinghua Science and Technology 2024年第2期29卷 430-446页

作者： Lei Xu Junhai zhai College of Mathematics and Information Science Hebei UniversityBaoding 071002China

Deep neural network(DNN)has strong representation learning ability,but it is vulnerable and easy to be fooled by adversarial *** order to handle the vulnerability of DNN,many methods have been *** general idea of existing methods is to reduce the chance of DNN models being fooled by observing some designed adversarial examples,which are generated by adding perturbations to the original *** this paper,we propose a novel adversarial example generation method,called *** from the existing methods,DCVAE-adv constructs adversarial examples by mixing both explicit and implicit perturbations without using original ***,the proposed method can be applied to both white box and black box *** addition,in the inference stage,the adversarial examples can be generated without loading the original images into memory,which greatly reduces the memory *** compared DCVAE-adv with three most advanced adversarial attack algorithms:FGSM,AdvGAN,and AdvGAN++.The experimental results demonstrate that DCVAE-adv is superior to these state-of-the-art methods in terms of attack success rate and transfer ability for targeted *** code is available at https://***/xzforeverlove/DCVAE-adv.

关键词： deep neural network adversarial examples white box attack black box attack robustness

Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 712-724页

作者： Dajun zhai Xiaoping Li Jun Shen College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)

Friction and Deformation Behavior of Human Skin During Robotic Sliding Massage Operation

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Journal of Bionic Engineering 2024年第4期21卷 1892-1904页

作者： Jingmei zhai Rixing Li Ziqing Su School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510000China

This study investigates the friction and deformation behavior of the skin in contact with a rigid massage ball and its influencing *** and stretching experiments were conducted using a collaborative robot experimental *** experiments encompassed a loading normal force range of 2 N to 18 N and a sliding speed range of 10 mm/s to 20 mm/*** friction response curve exhibits two different stages:static stick state and dynamic stick-slip stage,both of which have been mathematically *** analyzing the experimental data,we analyzed the effects of elastic modulus,sliding speed and normal loading force on skin tangential friction and tensile *** results indicate that as the normal load increases,both friction and deformation exhibit an ***,they decrease with an increase in elastic ***,while deformation diminishes with higher sliding speed,friction force remains relatively unaffected by *** observation can be attributed to the strain rate sensitivity resulting from the viscoelastic characteristics of the skin under substantial *** study advances the understanding of friction and deformation behavior during skin friction,offering valuable insights to enhance the operational comfort of massage robots.

关键词： Human skin Friction sliding Deformation Robotic massage Stereo image

Lead-free metal halide scintillator materials for imaging applications

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Science China(Information Sciences) 2024年第8期67卷 85-101页

作者： Junzhe LIN Dan GUO Tianrui zhai Department of Physics and Optoelectronic Engineering Beijing University of Technology

High-energy radiation detection and imaging technology has significant applications in highenergy physics research, medical imaging, and industrial monitoring. Lead-free metal halides exhibit exceptional potential for conducting indirect detection of high-energy radiation due to their characteristics of low toxicity, strong stability, high light yield, and large Stokes shift. This paper reviews the most recent advances in lead-free metal halide scintillator materials for X-ray imaging. Subsequently, it lists the most important parameters of scintillator performance and introduces the production procedures for single crystal, powder,and nanocrystal scintillators. Furthermore, it discusses the manufacturing of scintillator films with improved performance, focusing on large-area flexible scintillator films and the coupling with microstructures. Finally,it discusses current challenges and opportunities for enhancing X-ray imaging using lead-free metal halide scintillator materials.

关键词： lead-free metal halide scintillators imaging film luminescence

Bivariate attribution of the compound hot and dry summer of 2022 on the Tibetan Plateau

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Science China Earth Sciences 2024年第7期67卷 2122-2136页

作者： Baiquan ZHOU Panmao zhai Zhen LIAO State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081China

The extraordinarily high temperatures experienced during the summer of 2022 on the Tibetan Plateau(TP)demand attention when compared with its typical climatic *** absence of precipitation alongside the elevated temperatures resulted in 2022 being the hottest and driest summer on record on the TP since at least *** the susceptibility of the TP to climate change,this study employed large-ensemble simulations from the HadGEM3-A-N216 attribution system,together with a copula-based joint probability distribution,to investigate the influence of anthropogenic forcing,primarily global greenhouse gas emissions,on this unprecedented compound hot and dry event(CHDE).Findings revealed that the return period for the 2022 CHDE on the TP exceeds 4000 years,as determined from the fitted joint distributions derived using observational data spanning *** CHDE was directly linked to large-scale circulation anomalies,including the control of equivalent-barotropic high-pressure anomalies and the northward displacement of the subtropical westerly jet ***,anthropogenic forcing has,to some extent,promoted the surface warming and increased variability in precipitation on the TP in summer,establishing conditions conducive for the 2022 CHDE from a long-term climate change *** return period for a 2022-like CHDE on the TP was estimated to be approximately 283 years(142-613 years)by the large ensemble forced by both anthropogenic activities and natural ***,ensemble simulations driven solely by natural forcing indicated that the likelihood of occurrence of a 2022-like CHDE was almost *** outcomes underscore that the contribution of anthropogenic forcing to the probability of a 2022-like CHDE was 100%,implying that without anthropogenically induced global warming,a comparable CHDE akin to that observed in 2022 on the TP would not be possible.

关键词： Compound hot and dry event Tibetan Plateau Bivariate event attribution Anthropogenic forcing

Dynamics modeling and electromechanical coupling characteristics analysis of cage induction motors

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Science China(Technological Sciences) 2024年第3期67卷 709-724页

作者： ZHOU ZiWei CHEN ZaiGang zhai WanMing State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Induction motors, as typical electromechanical energy conversion devices, have received limited attention in previous studies on electromechanical coupling vibrations, precise modeling, and the use of electromechanical coupling effects for fault diagnosis and condition assessment in motor drive systems. This study proposes a comprehensive model of cage induction motors that integrates the multiple coupled circuit model with a rotor-bearing dynamics model. The model accounts for the linear increase in the magnetomotive force across the slot and incorporates the skidding characteristics of bearings in the rotor-bearing system. By calculating the time-varying mutual inductance parameters based on the air-gap distribution in the vibration environment, the electromechanical coupling vibration of the cage motor is investigated. Furthermore, this study examines the electromechanical coupling vibration characteristics influenced by various factors, including bearing clearances, radial loads, and the vertical excitation frequencies of the stators. The results show that the proposed model improves the excitation inputs for the electrical and mechanical systems of the motor compared with conventional models. Increased bearing clearance and radial load affect the current and torque similarly but have opposite effects on the slip ratio. This study provides a deeper understanding of electromechanical coupling mechanisms and facilitates the use of such phenomena for fault diagnosis and condition assessment in motor-driven systems.

关键词： cage induction motors rotor-bearing dynamics mutual inductance electromechanical testing current signal analysis

Jianpi-Huatan-Huoxue-Anshen formula ameliorates gastrointestinal inflammation and microecological imbalance in chemotherapytreated mice transplanted with H22 hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2024年第10期16卷 4209-4231页

作者： Ya-nan Wang Xiang-Yang zhai Zheng Wang Chun-Ling Gao Sui-Cai Mi Wen-Li Tang Xue-Min Fu Huai-Bang Li Li-Feng Yue Peng-Fei Li Sheng-Yan Xi Department of TCM Xiang’an HospitalSchool of MedicineXiamen UniversityXiamen 361102Fujian ProvinceChina Faculty of Chinese Medicine and State Key Laboratory of Quality Research in Chinese Medicine Macao University of Science and TechnologyMacao 999078China Department of Radiotherapy Chenggong Hospital of Xiamen UniversityPLA 73rd Army HospitalXiamen 361003Fujian ProvinceChina Department of Oncology Xiamen Hospital of Traditional Chinese MedicineXiamen 361015Fujian ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijing 100700China

BACKGROUND Jianpi-Huatan-Huoxue-Anshen formula[Tzu-Chi cancer-antagonizing&lifeprotecting II decoction(TCCL)]is a Chinese medical formula that has been clinically shown to reduce the gastrointestinal side effects of chemotherapy in cancer patients and improve their quality of ***,its effect and mechanism on the intestinal microecology after chemotherapy are not yet *** To discover the potential mechanisms of TCCL on gastrointestinal inflammation and microecological imbalance in chemotherapy-treated mice transplanted with hepatocellular carcinoma(HCC).METHODS Ninety-six mice were inoculated subcutaneously with HCC *** week later,the mice received a large dose of 5-fluorouracil by intraperitoneal injection to establish a HCC chemotherapy ***-six mice were randomly selected before administration,and feces,ileal tissue,and ileal contents were collected from each *** remaining mice were randomized into normal saline,continuous chemotherapy,Yangzheng Xiaoji capsulestreated,and three TCCL-treated *** treatment,feces,tumors,liver,spleen,thymus,stomach,jejunum,ileum,and colon tissues,and ileal contents were *** changes,serum levels of IL-1β,IL-6,IL-8,IL-10,IL-22,TNF-α,and TGF-β,intestinal SIgA,and protein and mRNA expression of ZO-1,NF-κB,Occludin,MUC-2,Claudin-1,and IκB-αin colon tissues were *** effect of TCCL on the abundance and diversity of intestinal flora was analyzed using 16S rDNA *** TCCL treatment improved thymus and spleen weight,thymus and spleen indexes,and body weight,decreased tumor volumes and tumor tissue cell density,and alleviated injury to gastric,ileal,and colonic mucosal *** proteins and genes associated with inflammation,IL-10,TGF-β,SIgA,ZO-1,MUC-2,and Occludin were upregulated,whereas NF-κB,IL-1β,IL-6,TNF-α,IL-22,IL-8,and IκB-αwere ***,TCCL increased the proportions of fecal Actinobacteria,AF12,Adlercreutzia,Clostridium,Coriobac

关键词： Chinese medicine Chemotherapy H22 hepatocellular carcinoma Intestinal barrier function Intestinal microecological balance

A CELL-CENTERED GODUNOV METHOD BASED ON STAGGERED DATA DISTRIBUTION,PART Ⅰ:ONE-DIMENSIONAL CASE

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Journal of Computational Mathematics 2024年第4期42卷 1172-1196页

作者： Jiayin zhai Xiao Li Zhijun Shen Institute of Applied Physics and Computational Mathematics LCPP.O.Box 8009-26Beijing 100088China College of Big Data and Internet Shenzhen Technology UniversityShenzhen 518118China Center for Applied Physics and Technology HEDPSPeking UniversityChina

This paper presents a cell-centered Godunov method based on staggered data distribu-tion in Eulerian *** motivation is to reduce the intrinsic entropy dissipation of classical Godunov methods in the calculation of an isentropic or rarefaction *** the same time,the property of accurate shock capturing is also *** analyzing the factors that cause nonphysical entropy in the conventional Godunov methods,we introduce two velocities rather than a single velocity in a cell to reduce kinetic energy dissipation.A series of redistribution strategies are adopted to update subcell quantities in order to improve *** examples validate that the present method can dramatically reduce nonphysical entropy *** subject classification:35Q35,76N15,76M12.

关键词： Godunov method Riemann solver Rarefaction wave Nonphysical entropy increase.

Quantum correlations in a chain-type quantum network

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Communications in Theoretical Physics 2024年第6期76卷 77-91页

作者： Xiaofei Qi Aihong zhai Lihua Yang School of Mathematical Science Shanxi UniversityTaiyuan 030006China Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi UniversityTaiyuan 030006China School of Mathematics and Information Technology Yuncheng UniversityYuncheng 044000China

A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some *** this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.

关键词： quantum correlation nonlocality entanglement chain-type quantum network