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Two Monte Carlo-based simulators for imaging-system modeling and projection simulation of flat-panel X-ray source

Nuclear Science and Techniques 2024年第7期35卷 31-46页

作者： Meng-Ke Qi Ting he Yi-Wen Zhou Jing Kang Zeng-Xiang Pan Song Kang Wang-Jiang Wu Jun Chen Ling-hong Zhou Yuan xu School of Biomedical Engineering Southern Medical UniversityGuangzhou510515China State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou510275China Department of Radiotherapy Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhou510515China

The advantages of a flat-panel X-ray source(FPXS)make it a promising candidate for imaging *** imaging-system modeling and projection simulation are critical for analyzing imaging performance and resolving overlapping projection issues in *** conventional analytical ray-tracing approach is limited by the number of patterns and is not applicable to FPXS-projection ***,the computation time of Monte Carlo(MC)simulation is independent of the size of the patterned arrays in *** study proposes two high-efficiency MC projection simulators for FPXS:a graphics processing unit(GPU)-based phase-space sampling MC(gPSMC)simulator and GPU-based fluence sampling MC(gFSMC)*** two simulators comprise three components:imaging-system modeling,photon initialization,and physical-interaction simulations in the ***-system modeling was performed by modeling the FPXS,imaging geometry,and *** gPSMC simulator samples the initial photons from the phase space,whereas the gFSMC simulator performs photon initialization from the calculated energy spectrum and fluence *** entire process of photon interaction with the geometry and arrival at the detector was simulated in parallel using multiple GPU kernels,and projections based on the two simulators were *** accuracies of the two simulators were evaluated by comparing them with the conventional analytical ray-tracing approach and acquired projections,and the efficiencies were evaluated by comparing the computation *** results of simulated and realistic experiments illustrate the accuracy and efficiency of the proposed gPSMC and gFSMC simulators in the projection calculation of various phantoms.

关键词： Flat-panel X-ray source(FPXS) Imaging-system modeling Projection simulation Monte Carlo-based simulators

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Current Loop Disturbance Suppression for Dual Three Phase Permanent Magnet Synchronous Generators Based on Modified Linear Active Disturbance Rejection Control

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Chinese Journal of Electrical Engineering 2024年第1期10卷 101-113页

作者： Dezhi xu Hu Yao Yang he Wenxiang Zhao School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China

A modified four-dimensional linear active disturbance rejection control(LADRC)strategy is proposed for a dual three-phase permanent magnet synchronous generator(DTP-PMSG)system to reduce cross-coupling between the d and q axis currents in the d-q subspace and harmonic currents in the x-y *** the d-q subspace,the proposed strategy uses a model-based LADRC to enhance the decoupling effect between the d and q axes and the disturbance rejection ability against parameter *** the x-y subspace,the 5th and 7th harmonic current suppression abilities are improved by using quasi-resonant units parallel to the extended state observer of the traditional *** proposed modified LADRC strategy improved both the steady-state performance and dynamic response of the DTP-PMSG *** experimental results demonstrate that the proposed strategy is both feasible and effective.

关键词： Dual three-phase permanent magnet synchronous generator current loop decoupling control harmonic suppression linear active disturbance rejection control

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Metal–phenolic coordination crystals derived magnetic hollow carbon spheres for ultrahigh electromagnetic wave absorption

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Nano Research 2024年第3期17卷 1616-1624页

作者： Hanxiao xu Zizhuang he Yiruo Wang Xiangru Ren Panbo Liu School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710129China

Owing to the tunable compositions and versatile functionality,the development of eco-friendly metal–phenolic coordination crystals derivatives is highly anticipated for electromagnetic wave *** this study,three kinds of magnetic hollow carbon spheres(HCSs)with macro-meso-microporous characteristics,including Fe/HCS,Co/HCS,and CoNi/HCS,are successfully fabricated via the co-operative hard template and self-assembling process,in which magnetic particles are encapsulated in carbon shell matrix after the pyrolysis of metal–polyphenol coordination crystals and further subsequent template *** the one hand,hierarchical macro-meso-micropores effectively balance the impedance gap between absorbers and air and introduce structural defects or distortion,leading to matched impedance and enhanced dipolar/defect *** the other hand,wrapped magnetic particles provide uncountable hetero-interfaces and induce ferromagnetic resonance,resulting in strengthened interfacial polarization and additional magnetic *** particular,enhanced minimum reflection loss(RL,min)and broadband effective absorption bandwidth(EAB)are achieved with only 10 wt.%filler ***,the RL,min and EAB values are-57.5 dB and 7.2 GHz for Fe/HCS,-50.0 dB and 5.8 GHz for Co/HCS,and-52.1 dB and 6.7 GHz for CoNi/HCS,***,this work provides us a modular-assembly strategy to regulate the hollow cavity of absorbers and simultaneously manipulates the chemical components of absorbers to regulate electromagnetic wave absorption performance.

关键词： hollow engineering hierarchical pores hetero-interfaces synergetic effect electromagnetic wave absorption

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Enterococcus faecalis provides protection during scavenging in carrion crow (Corvus corone)

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Zoological Research 2024年第3期45卷 451-463页

作者： Bin Hu Jia-Min Wang Qing-xun Zhang Jing xu Ya-Nan Xing Bo Wang Shu-Yi Han hong-xuan he CAS Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing Milu Ecological Research Center Beijing 102600China Beijing Capital International Airport Co. Ltd.Beijing 101300China

The gut microbiota significantly influences host physiology and provides essential ecosystem *** diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary *** carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging *** this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological *** present,however,the role of the gut microbiota remains incompletely *** this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,*** findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion ***,*** isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica *** showed that *** down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented *** colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory ***,*** exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

关键词： Carrion crow Facultative scavenger Gut microbiota Enterococcus faecalis 16S rRNA sequencing

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Nanoconfinement-induced water molecules and hydrogen molecules transport behaviors in ball-in-ball structure photocatalysts to improve hydrogen evolution

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Nano Research 2024年第5期17卷 3752-3760页

作者： Ben Chong Baorong xu he Li honghui Ou Guidong Yang XJTU-Oxford Joint International Research Laboratory of Catalysis School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China

The diffusion,adsorption/desorption behaviors of water molecules and hydrogen molecules are of great importance in heterogeneous photocatalytic hydrogen *** the study of structure-property-performance relationships,nanoconfined space provides an ideal platform to promote mass diffusion and transfer due to their extraordinary properties that are different from the bulk ***,we designed and prepared a nanoconfined CdS@SiO_(2)-NH_(2) nanoreactor,whose shell is composed of amino-functionalized silica nanochannels,and encapsulates spherical CdS as a photocatalyst *** and simulated results reveal that the amino-functionalized nanochannels promote water molecules’and hydrogen molecules’directional diffusion and *** molecules are enriched in the nanocavity between the core and the shell,and promote the interfacial photocatalytic *** a result,the maximized water enrichment and minimized hydrogen-occupied active sites enable photocatalyst with optimized mass transfer kinetics and localization electron distribution on the CdS surface,leading to superior hydrogen production performance with activity as high as 37.1 mmol·g^(-1)·h^(-1).

关键词： nanochannels photocatalytic hydrogen evolution mass transfer amino-functionalized CdS

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Role of Wnt Inhibitory Factor-1 in Inhibition of Bisdemethoxycurcumin Mediated Epithelial-to-Mesenchymal Transition in Highly Metastatic Lung Cancer 95D Cells

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Chinese Medical Journal 2015年第10期128卷 1376-1383页

作者： Jin-hong xu he-Ping Yang Xiang-Dong Zhou Hai-Jing Wang Liang Gong Chun-Lan Tang Department of Respiratory Medicine Southwest Hospital Third Military Medical University Chongqing 400038 China

Background：Bisdemethoxycurcumin （BDMC） is an active component of curcumin and a chemotherapeutic agent,which has been suggested to inhibit tumor growth,invasion and metastasis in multiple *** its contribution and mechanism of action in invasion and metastasis of non-small cell lung cancer （NSCLC） are not very ***,we tried to study the effects of BDMC on regulation of epithelial-to-mesenchymal transition （EMT）,which is closely linked to tumor cell invasion and ***：In this study,we first induced transforming growth factor-βl （TGF-β1） mediated EMT in highly metastatic lung cancer 95D ***,we studied the effects of BDMC on invasion and migration of 95D *** addition,EMT markers expressions were also analyzed by western blot and immunofluorescence *** contribution of Wnt inhibitory factor-1 （WIF-1） in regulating BDMC effects on TGF-β1 induced EMT were further analyzed by its overexpression and small interfering RNA knockdown ***：It was observed that BDMC inhibited the TGF-β1 induced EMT in 95D ***,it also inhibited the Wnt signaling pathway by upregulating WIF-1 protein *** addition,WIF-1 manipulation studies further revealed that WIF-1 is a central molecule mediating BDMC response towards TGF-β1 induced EMT by regulating cell invasion and ***：Our study concluded that BDMC effects on TGF-β1 induced EMT in NSCLC are mediated through WIF-1 and elucidated a novel mechanism of EMT regulation by BDMC.

关键词： Bisdemethoxycurcumin Epithelial-to-mesenchymal Transition Lung Cancer Wnt Inhibitory Factor- 1 Wnt Pathway

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In-situ isothermal aging TEM analysis of a micro Cu/ENIG/Sn solder joint for flexible interconnects

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Journal of Materials Science & Technology 2024年第2期169卷 42-52页

作者： Jinhong Liu Jianhao xu Kyung-Wook Paik Peng he Shuye Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China Department of materials science and engineering KAIST291 Daehak-roYuseong-guDaejeon305-338Republic of Korea

Sn/ENIG has recently been used in flexible interconnects to form a more stable micron-sized metallurgical joint,due to high power capability which causes solder joints to heat up to 200℃.However,Cu_(6)Sn_(5)which is critical for a microelectronic interconnection,will go through a phase transition at temperatures between 186 and 189℃.This research conducted an in-situ TEM study of a micro Cu/ENIG/Sn solder joint under isothermal aging test and proposed a model to illustrate the mechanism of the microstructural *** results showed that part of the Sn solder reacted with Cu diffused from the electrode to formη´-Cu_(6)Sn_(5)during the ultrasonic bonding process,while the rest of Sn was left and enriched in a region in the solder *** the enriched Sn quickly diffused to both sides when the temperature reached 100℃,reacting with the ENIG coating and Cu to form(Ni_(x)Cu_(1-x))_(3)Sn_(4),AuSn_(4),and Cu_(6)Sn_(5)*** entering the heat preservation process,the diffusion of Cu from the electrode to the joint became more intense,resulting in the formation of Cu_(3)*** scallop-type Cu_(6)Sn_(5)and the seahorse-type Cu_(3)Sn constituted a typical two-layered structure in the solder *** importantly,the transition betweenηandη’was captured near the phase transition temperature for Cu_(6)Sn_(5)during both the heating and cooling process,which was accompanied by a volume shifting,and the transition process was further *** research is expected to serve as a reference for the service of micro Cu/ENIG/Sn solder joints in the electronic industry.

关键词： In-situ TEM observation Isothermal aging Micro Cu/ENIG/Sn solder joint Cu_(6)Sn_(5)phase transition

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Comparative evaluation of SPE methods for biotoxicity assessment of water and wastewater:Linkage between chemical extracting efficiency and biotoxicity outcome

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Journal of Environmental Sciences 2024年第8期142卷 33-42页

作者： Jiawei Zhou Shihao Wang Xiwei he hongqiang Ren xu-Xiang Zhang State Key Laboratory of Pollution Control and Resource Reuse School of EnvironmentNanjing UniversityNanjing 210023China

Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of ***,more chemical mixture does not necessarily translate to higher combined ***,there is a need to establish the link between chemical extracting efficiency and biotoxicity outcome to standardize extraction methods for biotoxicity assessment of environmental *** study compares the performance of five different extraction phases in solid phase extraction(SPE),namely HLB,HLB+Coconut,C18 cartridge,C18 disk and Strata-X,and evaluated their chemical extracting efficiencies and biotoxicity *** quantitatively assessed cytotoxicity,acute toxicity,genotoxicity,estrogenic activity,and neurotoxicity of the extracts using in vitro bioassays and characterized the chemical extracting efficiencies of the SPE methods through chemical recoveries of 23 model compounds with different polarities and total organic *** Pareto ranking,we identified HLB+Coconut as the optimal SPE method,which exhibited the highest level of water sample biotoxicity and recovered the most chemicals in water *** found that the biotoxicity outcomes of the extracted water samples significantly and positively correlated with the chemical extracting efficiencies of the SPE ***,we observed synchronous changing patterns in biotoxicity outcome and chemical extracting efficiencies in response to increasing sample volumes per cartridge(SVPC)during *** findings underscore that higher chemical extracting efficiency of SPE corresponds to higher biotoxicity outcome of environmental water samples,providing a scientific basis for standardization of SPE methods for adequate assessment of biotoxicities of environmental waters.

关键词： Biotoxicity Chemical recovery Solid phase extraction Surface water Wastewater

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heat distribution model under hydrogen-rich low-carbon conditions in blast furnace

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Journal of Iron and Steel Research International 2024年第3期31卷 584-594页

作者： Gang Wang Jun xu Kun he Zhong-ping Zou Hao Bai School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing 100083China CISDI Low-Carbon Blast Furnace Research Office MCC Low-Carbon Technology Research InstituteChongqing 401122China

Low carbon development of blast furnaces is one of the key technological directions in the current development of *** to the differences in the physical and chemical properties of hydrogen and carbon,hydrogen-rich media entering a blast furnace will change the heat distribution,thus affecting the stability of ***,a heat distribution model was proposed to study the temperature distribution in a blast furnace,simultaneously considering gas-solid heat exchange,slag and iron melting,and chemical *** model was used to analyze the temperature distribution of a 2300 m^(3) blast furnace and was verified via comparison with actual production ***,the effects of the injection rate of hydrogen-rich media,H2 concentration,and oxygen enrichment rate of the blast on the temperature distribution were *** indicated that the increase in the injection rate of the hydrogen-rich media decreased the amount of direct reduction and led to an increase in the furnace ***,an increase in the oxygen enrichment rate led to a decrease in the furnace temperature,but could reduce the solid fuel ratio,while the change in H2 concentration had less effect on the temperature *** combination of hydrogen-rich media injection and the increase in the oxygen enrichment rate would help to adjust the temperature distribution to the same level as the conventional blast furnace conditions.

关键词： heat distribution Blast furnace Low-carbon condition Hydrogen enrichment Calculation model

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CFD-DEM study on the synergistic effect of coke consumption and particle dynamics in the blast furnace raceway

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Particuology 2024年第6期89卷 270-278页

作者： Peng xu Peng Han Zhijun he Xizhong An Kang Sun Lihua Gao Key Laboratory of Green Low-Carbon and Intelligent Metallurgy School of Materials and MetallurgyUniversity of Science and Technology LiaoningAnshan 114000China Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang110819China

In this study,the gas-solid flow process in the blast furnace raceway is numerically simulated using coupled computational fluid dynamics and the discrete element method(CFD-DEM).The coke reaction kinetics data are imported into the DEM model to reproduce the consumption process of each coke *** effects of inlet gas velocity and angle on the morphology of the raceway,coke consumption rate,coke bed temperature,and particle size distribution in the blast process are systematically investigated and *** results show that the consumption of coke particles promotes the formation of raceways during the blast *** the same time,a coke mixture layer is produced at the edge of the *** higher the inlet gas velocity,the thicker the coke mixture layer in the middle and upper parts of the raceway region,and the larger the proportion of small particles in the coke mixture *** effect of the inlet gas angle on the raceway region is less than the inlet gas ***,with the increase in the inlet gas angle,the high-temperature region of the coke bed extends downward gradually,which is conducive to activating the hearth.

关键词： Blast furnace Raceway Multiphase flow CFD-DEM Modeling

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