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Design and calculation of a side-coupled accelerating structure

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Nuclear Science and Techniques 2017年第11期28卷 204-209页

作者： Ming-Xuan Liu cong-feng wu Yun-Gai Tang Gui-Rong Huang National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China

In this paper, we present the design and optimization of a side-coupled accelerating structure with an energy switch. The beam parameters are optimized, and the electric field asymmetry in the first cell is analyzed. The new structure we designed has an improvement of 10 times in the accelerating field symmetry. Thermo-mechanical analysis is performed based on the electromagnetic results. The highest temperature is 72.5 ℃ at the nose cone, and the maximal deformation is 73 μm at the outer edge of the coupling cavity.

关键词： Side-coupled accelerating structure Energy switch Beam dynamics Asymmetry Thermomechanical analysis

Performance comparison of the two ICRF antennas in EAST

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Nuclear Science and Techniques 2016年第2期27卷 1-5页

作者： Hua Yang cong-feng wu Sai Dong Yan-Ping Zhao Xin-Jun Zhang Lei Shang National Synchrotron Radiation Laboratory University of Science and Technology of China Institute of Plasma Physics Chinese Academy of Sciences

The experimental advanced superconducting Tokamak has two suits of ion cyclotron radio frequency heating systems, in which the two antennas are of different structures. Their performance is assessed and compared by CST microwave studio. The radiating capacity of antennas and the arcing around them are estimated. The impurity release is analyzed by the radio frequency(RF) potential in the plasma sheath. The simulation results show that the radiating capacity for the folded antenna(I-port) is better than those for the double loops antenna(B-port). However,the folded antenna is worse than the double loops antenna in terms of breakdown. Moreover, the impurity production is relevant to spectrum shaping. The RF potential at(0, π,π, 0) phasing with the peak of spectrum k//= 8.5 m^(-1)is lower than the one with other phases. The impurity is reduced obviously when the folded antenna is powered with(0, π, π, 0) phasing.

关键词：环天线性能比较 ICRF 超导托卡马克装置等离子体鞘层辐射能力电位分析微波工作室

Corrosion behavior of Zr–Nb–Cr cladding alloys

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Rare Metals 2013年第5期32卷 480-485页

作者： Wei-Jia Gong cong-feng wu Hang Tian Xiao-Dong Ni Hai-Long Zhang Xi-Tao Wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing School of Mathematics and Physics University of Science and Technology Beijing

Zr-Nb-Cr alloys were used to evaluate the effects of alloying elements Nb and Cr on corrosion behavior of zirconium alloys. The microstructures of both Zr substrates and oxide films formed on zirconium alloys were characterized. Corrosion tests reveal that the corro- sion resistance of ZrxNb0.1Cr （x = 0.2, 0.5, 0.8, 1.1; wt%） alloys is first improved and then decreased with the increase of the Nb content. The best corrosion resistance can be obtained when the Nb concentration in the Zr matrix is nearly at the equilibrium solution, which is closely responsible for the formation of columnar oxide grains with protective characteristics. The Cr addition degrades the corrosion resistance of the *** alloy, which is ascribed to Zr（Cr,Fe,Nb）2 precipitates with a much larger size than β-Nb.

关键词： Zirconium alloys Corrosion Precipitates Alloying elements Transmission electron microscope

Development of a control system for the fourth-harmonic cavity of the HLS storage ring

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Nuclear Science and Techniques 2018年第11期29卷 159-165页

作者： Wen-Bo wu Ke Xuan Wei Xu Ji-Gang Wang Chuan Li Gong-Fa Liu cong-feng wu Jing-Yi Li National Synchrotron Radiation Laboratory University of Science and Technology of China Institute of High Energy Physics CAS

Harmonic RF cavities are commonly used in storage rings to lengthen the bunches and thus suppress the beam's instabilities and increase its Touschek lifetime. The voltage and phase of the electromagnetic fields in the harmonic cavity are of great importance for stretching the bunch. In the Hefei Light Source storage ring, a passive fourth-harmonic cavity is installed, and the cavity is monitored and controlled by an analog control module provided by its manufacturer. To vary and maintain the voltage of the harmonic cavity in a more effective way, a digital proportional, integral, and derivative feedback system based on the Experimental Physics and Industrial Control System is developed on top of the analog control module. This paper reports the details of the development of this voltage control system. Some test and operational results are also presented.

关键词： Bunch length High-harmonic cavity EPICS PID feedback

Antimicrobial resistance characteristics and phylogenetic relationships of pleuromutilin-resistant Enterococcus isolates from different environmental samples along a laying hen production chain

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Journal of Environmental Sciences 2024年第3期137卷 195-205页

作者： cong Lin Yuxuan feng Xianjun Xie Haoyu Zhang Jie wu Yixiao Zhu Jing Yu Jingyi feng Wen Su Shanming Lai Anyun Zhang Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province Key Laboratory of Bio-Resource and Eco-Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengdu 610065China

Antimicrobial resistance in the laying hen production industry has become a serious public health *** antimicrobial resistance and phylogenetic relationships of the common conditional pathogen Enterococcus along the laying hen production chain have not been systematically clarified.105 Enterococcus isolates were obtained from 115 environmental samples (air,dust,feces,fies,sewage,and soil) collected along the laying hen production chain (breeding chicken,chick,young chicken,and commercial laying hen).These Enterococcus isolates exhibited resistance to some clinically relevant antibiotics,such as tetracycline (92.4%),streptomycin (92.4%),and erythromycin (91.4%),and all strains had multidrug resistance *** genome sequencing characterized 29 acquired antibiotic resistance genes (ARGs) that conferred resistance to 11 classes of antibiotics in 51pleuromutilin-resistant Enterococcus isolates,and lsa(E),which mediates resistance to pleuromutilins,always co-occurred with lnu(B).Alignments with the Mobile Genetic Elements database identified four transposons (Tn554,Tn558,Tn6261,and Tn6674) with several ARGs(erm(A),ant(9)-la,fex(A),and optrA) that mediated resistance to many clinically important ***,we identified two new transposons that carried ARGs in the Tn554 family designated as Tn7508 and Tn7492.A complementary approach based on conventional multi-locus sequence typing and whole genome single nucleotide polymorphism analysis showed that phylogenetically related pleuromutilin-resistant Enterococcus isolates were widely distributed in various environments on different production *** results indicate that environmental contamination by antimicrobial-resistant Enterococcus requires greater attention,and they highlight the risk of pleuromutilin-resistant Enterococcus and ARGs disseminating along the laying hen production chain,thereby warranting effective disinfection.

关键词： Antimicrobial resistance Enterococcus Laying hen production chain Pleuromutilin

Evolution of the porous structure for phosphoric acid etching carbon as cathodes in Li–O_(2) batteries:Pyrolysis temperature-induced characteristics changes

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Carbon Energy 2024年第1期6卷 172-181页

作者： Feiyang Yang Ying Yao Yunkai Xu cong Wang Meiling Wang Jingjie Ren Cunzhong Zhang feng wu Jun Lu Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijingChina Beijing Institute of Technology Chongqing Innovation Center ChongqingChina College of Chemical and Biological Engineering Zhejiang UniversityHangzhouChina

Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains ***,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained *** open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.

关键词： biomass Li-O_(2) battery oxygen catalysts porous carbon temperature parameters

Brain Cognition Mechanism-Inspired Hierarchical Navigation Method for Mobile Robots

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Journal of Bionic Engineering 2024年第2期21卷 852-865页

作者： Qiang Zou Chengdong wu Ming cong Dong Liu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110819China School of Mechanical Engineering Dalian University of TechnologyDalian116024China

Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist poor robustness and low cognitive *** a new navigation technology that draws inspiration from mammal’s navigation,bionic navigation method can map perceptual information into cognitive space,and have strong autonomy and environment *** improve the robot’s autonomous navigation ability,this paper proposes a cognitive map-based hierarchical navigation ***,the mammals’navigation-related grid cells and head direction cells are modeled to provide the robots with location *** then a global path planning strategy based on cognitive map is proposed,which can anticipate one preferred global path to the target with high efficiency and short ***,a hierarchical motion controlling method is proposed,with which the target navigation can be divided into several sub-target navigation,and the mobile robot can reach to these sub-targets with high confidence ***,some experiments are implemented,the results show that the proposed path planning method can avoid passing through obstacles and obtain one preferred global path to the target with high efficiency,and the time cost does not increase extremely with the increase of experience nodes *** motion controlling results show that the mobile robot can arrive at the target successfully only depending on its self-motion information,which is an effective attempt and reflects strong bionic properties.

关键词： Bionic navigation Spatial localization cells Global path planning Hierarchical motion controlling

Sedimentary architecture of submarine channel-lobe systems under different seafloor topography:Insights from the Rovuma Basin offshore East Africa

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Petroleum Science 2024年第1期21卷 125-142页

作者： Mei Chen Sheng-He wu Rui-feng Wang Jia-Jia Zhang Peng-Fei Xie Min Wang Xiao-feng Wang Ji-Tao Yu Qi-cong Xiong State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Faculty of Geosciences University of BremenBremen28359Germany MARUM-Center for Marine and Environmental Sciences University of BremenBremen28359Germany Research institute of Petroleum Exploration and Development PetroChinaBeijing10083China School of Geosciences Yangtze UniversityWuhan 100083HubeiChina CNODC Mozambique Ltd. Beijing 100034China

Seafloor topography plays an important role in the evolution of submarine ***,it is still not so clear how the shape of slope affects the three-dimensional(3-D)architecture of submarine *** this study,we analyze the effect of topography factors on different hierarchical lobe architectures that formed during Pliocene to Quaternary in the Rovuma Basin offshore East *** characterize the shape,size and growth pattern of different hierarchical lobe architectures using 3-D seismic *** find that the relief of the topographic slope determines the location of preferential deposition of lobe complexes and single *** the topography is irregular and presents topographic lows,lobe complexes first infill these *** lobes are deposited preferentially at positions with higher longitudinal(***-slope)slope *** the longitudinal slope becomes higher,the aspect ratio of the single lobes ***(***-slope)topography does not seem to have a strong influence on the shape of single lobe,but it seems to affect the overlap of single *** the lateral slope gradient is relatively high,the single lobes tend to have a larger overlap ***,as the average of lateral slope and longitudinal slope gets greater,the width/thickness ratio of the single lobe is smaller,*** tend to accumulate *** results demonstrate that the shape of slopes more comprehensively influences the 3-D architecture of lobes in natural deep-sea systems than previously other lobe deposits and analogue experiments,which helps us better understand the development and evolution of the distal parts of turbidite systems.

关键词： Submarine fan Seafloor topography Sedimentary architecture Slope system SW Indian ocean

Tighter sum uncertainty relations via(α,β,γ)weighted Wigner–Yanase–Dyson skew information

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Communications in Theoretical Physics 2024年第3期76卷 91-99页

作者： cong Xu Zhaoqi wu Shao-Ming Fei School of Mathematical Sciences Capital Normal UniversityBeijing 100048China Department of Mathematics Nanchang UniversityNanchang 330031China Max-Planck-Institute for Mathematics in the Sciences 04103 LeipzigGermany

We establish tighter uncertainty relations for arbitrary finite observables via(α,β,γ)weighted Wigner–Yanase–Dyson((α,β,γ)WWYD)skew *** results are also applicable to the(α,γ)weighted Wigner–Yanase–Dyson((α,γ)WWYD)skew information and the weighted Wigner–Yanase–Dyson(WWYD)skew *** also present tighter lower bounds for quantum channels and unitary channels via(α,β,γ)modified weighted Wigner–Yanase–Dyson((α,β,γ)MWWYD)skew *** examples are provided to illustrate the tightness of our uncertainty relations.

关键词： quantum channels (α,β,γ)WWYD skew information (α,β,γ)MWWYD skew information uncertainty relations