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Scan system for arbitrary-shaped samples at the synchrotron radiation facility

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Nuclear Science and Techniques 2017年第5期28卷 18-27页

作者： Xu-Ying Lan Dong-Xu Liang cheng-wen mao Shanghai Institute of Applied Physics Chinese Academy of Sciences Zhangjiang Campus Shanghai 201204 China

X-ray fluorescence(XRF) scan methodology is important for elemental mapping of samples at a synchrotron radiation facility. To save the experiment time and improve the experiment efficiency, one should develop an efficient XRF scan method. In this paper, a new scan mode is presented. It can map arbitrary-shaped areas withou stopping the motors. The control and data acquisition system integrates motor controlling, detector triggering, and data acquisition and storage. The system realizes the arbitrary-shaped 2D-mapping and fluorescence data acquisition synchronously. SR-XRF mapping has been performed with a standard gold mask to verify the validity of this method a beamline BL15U1 of the Shanghai Synchrotron Radiation Facility. The results show that this method reduces the tota scan time and improves the experiment efficiency.

关键词： Synchrotron radiation X-ray fluorescence mapping EPICS XPS controller

Elastic wave insulation and propagation control based on the programmable curved-beam periodic structure

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1791-1806页

作者： Jiajia mao Hong cheng Tianxue MA Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures Department of MechanicsSchool of MathematicsStatistics and MechanicsBeijing University of TechnologyBeijing 100124China Department of Mechanics School of Physical Science and EngineeringBeijing Jiaotong UniversityBeijing 100044China

Curved-beams can be used to design modular multistable metamaterials(MMMs)with reprogrammable material properties,i.e.,programmable curved-beam periodic structure(PCBPS),which is promising for controlling the elastic wave *** PCBPS is theoretically equivalent to a spring-oscillator system to investigate the mechanism of bandgap,analyze the wave propagation mechanisms,and further form its geometrical and physical criteria for tuning the elastic wave *** the equivalent model,we calculate the analytical solutions of the dispersion relations to demonstrate its adjustability,and investigate the wave propagation characteristics through the *** validate the equivalent system,the finite element method(FEM)is *** is revealed that the bandgaps of the PCBPS can be turned on-and-off and shifted by varying its physical and geometrical *** findings are highly promising for advancing the practical application of periodic structures in wave insulation and propagation control.

关键词： curved-beam based periodic structure equivalent stiffness spring-oscillator system dispersion relation wave propagation

Modelling the formation and dissolution behavior of alumina agglomerate in the cryolite

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Particuology 2024年第3期86卷 211-222页

作者： Jiaqi Wang mao Li Benjun cheng Hesong Li School of Energy Science and Engineering Central South UniversityChangsha410083China

The presence of alumina agglomerates seriously affects the current efficiency of the aluminum electrolysis *** the dynamic dissolution process of agglomerates is essential to improve the current efficiency of aluminum electrolysis.A mathematical model is proposed to describe the different phenomena from the formation until complete dissolution of *** permeation and solidification processes of cryolite,a semi-analytical mathematical model is developed to formulate the formation,melting and dissolution processes of agglomerates,and the time duration for each stage is *** and heat mass transfer of agglomerates are explored based on the packing theory and mechanism of heat mass transfer in wet porous *** approach is applied to investigate the main factors affecting the dissolution stages and porosity of *** results show that the superheat has a great influence on the formation and melting stage,the diameter of agglomerates can reach 14.93 mm for 200 particles *** density decreases with the increase of agglomerated particle number,which varies in the range of 2.27-2.28 g/cm^(3).The average dissolution rate of agglomerates is about 1.83×10^(-5)-2.95×10^(-5) kg/s within the range of alumina concentration in this study.

关键词： Mathematical model Alumina agglomerate Porous media Packing theory Heatand mass transfer

Dynamic steric confinement effect expands the frontier of Cu-catalyzed asymmetric propargylic aminations

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Science China Chemistry 2024年第10期67卷 3181-3183页

作者： Peng Chen mao-mao Zhang wen-Jing Xiao Liang-Qiu Lu Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079China Wuhan Institute of Photochemistry and Technology Wuhan 430082China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics(LICP)Chinese Academy of SciencesLanzhou 730000China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

Chiralα-tertiary amines and related azacycles are commonly found in many natural products,pharmaceuticals and agrochemicals[1].Copper-catalyzed asymmetric propargylic amination(APA)reactions have been established as a reliable method to access enantio-enriched propargylic amines,largely due to the seminal contribution of Nishibayashi et al.[2]and van Maarseveen et al.[3]in 2008.

关键词： catalyzed asymmetric amines

Design strategy and relevant flow mechanisms of highly loaded 3D compressor tandem cascades

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Chinese Journal of Aeronautics 2024年第7期37卷 220-235页

作者： Xiaochen mao Yunyu WANG Zhihua DING Hao cheng Bo LIU School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China The National Key Laboratory of Science and Technology on Aerodynamic Design and Research Xi’an 710129China Xi’an Thermal Power Research Institute Co.Ltd Xi’an 710072China

To investigate the design strategy of highly loaded tandem cascades at both the midspan and endwall,the overall performance and flow mechanisms of four typical tandem cascades based on the optimization were analyzed from multiple perspectives *** results show that the interference effects on the Front Blade(FB)and Rear Blade(RB)should not be overlooked during the design phase,and the design strategies at the midspan and endwall are completely *** the midspan,the optimization aims to increase the interference effects and the strength of the gap jet while maintaining the same load on the FB and ***,the endwall optimal airfoil exhibits weakening interference effects,advancement of the gap jet location,and load transfer from the FB to *** further analysis of flow characteristics,the midspan optimal airfoil is beneficial for inhibiting the low-energy fluid from interacting with the suction surface of RB under the design condition,but results in earlier occurrence of corner *** endwall optimal airfoil helps suppress the development of the secondary flow and delay the onset of corner ***,by combining the benefits of these two design approaches,additional forward sweep effects are achieved,further enhancing the performance of the tandem cascade.

关键词： Tandem cascade Interference effect Vortex structure Load split Compressor

Shape optimisation of basin insulator for DC gas insulated switchgear/gas insulated transmission lines based on artificial bee colony algorithm

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High Voltage 2024年第2期9卷 275-286页

作者： Yi Luo Shiyi mao Ju Tang Zijun Pan cheng Pan State Key Laboratory of Power Grid Environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhanChina

The surface charge accumulation on the basin insulator is a particular problem in high-voltage direct current(HVDC)gas insulated switchgears(GIS)and gas insulated trans-mission lines(GIL),which restricts the development and application of extra/ultra high-voltage(EHV/UHV)*** surface charge distribution and anti-flashover performance are closely related to the insulator *** obtain the optimal basin insulator,a shape optimisation model based on artificial bee colony algorithm was established,and the minimisation objective functions based on capacitive(initial)electric field distribution and resistive(steady-state)electric field distribution were respectively *** optimisation results of the two objective functions were calculated,and the electric field and charge distribution on the surface of the insulator before and after optimisation were evaluated and compared using the simulation *** results indicated that the optimisation based on the capacitive electric field can significantly inhibit the surface charge accumulation,and the optimised insulator can significantly reduce the surface normal electric field and make the distribution of the tangential electric field more uniform,and the maximum tangential electric field can be reduced by 10%;the optimisation based on resistive electric field can achieve similar results,but requires more computational *** on the results,the‘anti-charge’basin insulator structure suitable for the DC field was given.

关键词： insulator artificial charge

Basilic vein variation encountered during surgery for arm vein port:A case report

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World Journal of Clinical Cases 2024年第12期12卷 2086-2091页

作者： cheng-Da Hu Rui Lv Ya-Xin Zhao Ming-Hao Zhang Hong-Dou Zeng Yi-wen mao Department of Breast Surgery The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325000Zhejiang ProvinceChina

BACKGROUND Venous variations are uncommon and usually hard to identify,and basilic vein variation is particularly *** vein variation usually presents without any clinical symptoms and is often regarded as a benign *** case was a patient with congenital basilic vein variation encountered during surgery for an infusion *** SUMMARY We documented and analyzed an uncommon anatomical variation in the basilic vein encountered during arm port *** peculiarity has hitherto remained undescribed in the *** offer remedial strategies for addressing this anomaly in the future and precautionary measures to circumvent its *** conducted a comprehensive review of analogous cases in the literature,offering pertinent therapeutic recommendations and solutions,with the aim of enhancing the efficacy and safety of future arm port *** Venous variation is rare and requires detailed intraoperative and postoperative examination to ensure accuracy,so as not to affect subsequent treatment.

关键词： Totally implantable venous access ports Arm ports Venous variation Postoperative breast cancer Systematic review Case report

One-year observation of the mixing states of oxygenated organics-containing single particles in Guangzhou,China

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 155-169页

作者： Liyuan mao Suxia Yang Xiaoya cheng Sulin Liu Duanying Chen Zhen Zhou Mei Li chenglei Pei Chunlei cheng Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for the On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou510632China Guangzhou Research Institute of Environment Protection Co. Ltd.Guangzhou510620China Guangzhou Ecological and Environmental Monitoring Center of Guangdong Province Guangzhou510030China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi’an710061China

Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still *** study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in ***,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire *** OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated *** addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in ***,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in *** addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of ***,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

关键词： Oxygenated organics Single particles Mixing state Secondary formation Photochemistry

A chitosan-based antibacterial hydrogel with injectable and self-healing capabilities

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Marine Life Science & Technology 2024年第1期6卷 115-125页

作者： Rui Chen Yanan Hao Secundo Francesco Xiangzhao mao wen-Can Huang State Key Laboratory of Marine Food Processing and Safety Control College of Food Science and EngineeringOcean University of ChinaQingdao 266404China Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Qingdao 266237China Qingdao Key Laboratory of Food Biotechnology Qingdao 266404China Key Laboratory of Biological Processing of Aquatic Products China National Light IndustryQingdao 266404China Istituto di Scienze e Tecnologie Chimiche“Giulio Natta” Consiglio Nazionale delle Ricerche via Mario Bianco 920131 MilanItaly

The presence of bacteria directly affects wound ***-based hydrogel biomaterials are a solution as they offer advantages for wound-healing applications due to their strong antimicrobial ***,a double-cross-linking chitosanbased hydrogel with antibacterial,self-healing,and injectable properties is *** chitosan was successfully prepared,and the thiolated chitosan molecules were cross-linked by Ag-S coordination to form a supramolecular ***,the amine groups in the thiolated chitosan covalently cross-linked with genipin to further promote hydrogel *** vitro experimental results indicate that hydrogel can release Ag^(+)over an extended time,achieving an antibacterial rate of over 99% against Escherichia coli and Staphylococcus *** to the reversible and dynamic feature of Ag-S coordination,an antibacterial hydrogel exhibited injectable and self-healing ***,the hydrogel showed excellent biocompatibility and biodegradability.

关键词： Hydrogel Chitosan Silver ion Cross-linking Antibacterial