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A precision sampling system for fast corrector power supply of photon source

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Radiation Detection Technology and Methods 2023年第1期7卷 139-148页

作者： Peng Liu F.L.Long y.Z.du Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China University of Chinese Academy of Sciences Beijing100049China

Purpose At present,the high-energy photon source(HEPS)is under construction in *** has beam emittance lower than 40 pm *** order to ensure low beam emittance,a high-performance fast orbit feedback system(FOFB)is designed for fast and accurate correction of beam *** FOFB needs to have the smallest adjustment ***,as the execution unit of the FOFB system,the output current resolution of the fast corrector power supply needs to be as small as *** FOFB systems,precise correction of beam orbit is required for fast corrector power supply with output current resolution better than 60μA.A precision digital sampling system needs to be designed to meet the high requirements of output current *** The precision operational amplifier is used to complete the scaling and sampling of *** precision operational amplifier is used as the front-end processing in the circuit design to complete the amplitude processing and ***,the precision operational amplifier is used as the driver of the precision analog to digital converter(ADC)chip.A precision ADC chips based on oversampling technology is *** this scheme,the selected ADC chip can have the advantages of both high speed and high precision.A simulation prototype is built for test,and the performance parameters of key chips in the design are *** A precision voltage reference is used to test the designed digital sampling *** test results showed that the acquisition system has an effective resolution of 21.6 *** HEPS fast corrector power supply is used for testing the developed precision sampling *** test result showed that the output current resolution of fast corrector power supply is lower than 16μA.

关键词： Photon source FOFB Fast corrector High precision Over sampling ADC High resolution

Microstructure of Laser Remelted Ni-base Alloy Coating on Stainless Steel

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Journal of Materials Science & Technology 1998年第1期14卷 49-52页

作者： Gao, y Liang, y Shi, CX Inst Aeronaut Mat Beijing 100095 Peoples R China Chinese Acad Sci Inst Met Res Shenyang 110015 Peoples R China

A 5 kW CW CO2 gas laser was used to produce NiCrBSi superalloy coatings. Powders were preplaced by plasma-spraying. The microstructure and chemical composition of the coating have been studied by SEM, XRD and HREM. The results show the coating microstructure is fine dendrites, composed of gamma matrix, gamma' and boride (NiB) eutectic, the lattice parameter of the gamma matrix is 0.3572 nm and there is a metallurgical bonding in interface.

关键词： Stainless steel

A hyperbolic Lindstedt-Poincare method for homoclinic motion of a kind of strongly nonlinear autonomous oscillators

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Acta Mechanica Sinica 2009年第5期25卷 721-729页

作者： y.y.Chen S.H.Chen K.y.Sze Department of Applied Mechanics and Engineering Sun yat-sen University Department of Mechanical Engineering The University of Hong Kong Department of Applied Mechanics and Engineering Sun Yat-sen University

A hyperbolic Lindstedt-Poincare method is presented to determine the homoclinic solutions of a kind of nonlinear oscillators, in which critical value of the homoclinic bifurcation parameter can be determined. The generalized Lienard oscillator is studied in detail, and the present method＇s predictions are compared with those of Runge-Kutta method to illustrate its accuracy.

关键词： Lindstedt-Poincare method Hyperbolic function Nonlinear autonomous oscillator - Homoclinic orbit

Modification of the Micro Arc-oxidized Ti Surface for Implant Applications

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Journal of Bionic Engineering 2021年第6期18卷 1391-1399页

作者： Eren yılmaz Department of Welding Technology Sakarya Applied Sciences UniversityArifi ye Vocational High School54187SakaryaTurkey Sakarya Applied Sciences University Materials Research Center(SUMAR) 54187SakaryaTurkey

Surface treatments applied to titanium and its alloys for implant applications are important for the development of bio *** this study,first an oxide layer was formed on the surface of the titanium plate by micro arc oxidation,and then both calcium phosphate and calcium phosphate/chitosan accumulation were performed for different samples by the sol-gel ***-SEM/EDS examinations,XRD,FTIR and thermal analysis were performed for these micro arc-oxidized,calcium phosphate-coated and calcium phosphate/chitosan-coated *** surface roughnesses for these surfaces were measured between 10μm and 100μm,suitable for bone development on the *** effect of chitosan addition on the calcium phosphate-coated surface on apatite formation ability and antibacterial properties was *** the addition of chitosan slows down the formation of apatite,it ensured that the coating had antibacterial *** calcium phosphate/chitosan biocomposite obtained can be recommended for dental and orthopedic implants.

关键词： Micro arc oxidation Sol-gel Hydroxyapatite Chitosan Implant

In vitro Study on Biodegradable AZ31 Magnesium Alloy Fibers Reinforced PLGA Composite

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Journal of Materials Science & Technology 2013年第6期29卷 545-550页

作者： y.H.Wu N.Li y.Cheng y.F.Zheng y.Han Center for Biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary StudiesPeking University Department of Materials Science and Engineering College of EngineeringPeking University State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University

AZ31 magnesium alloy fibers reinforced poly（lactic-co-glycolic acid）（PLGA） composites were prepared and their mechanical property, immersion corrosion behavior and biocompatibility were studied. The tensile test showed that with the addition of AZ31 fibers, the composites had a significant increment in tensile strength and elongation. For the direct cell attachment test, all the cells showed a healthy morphology and spread well on the experimental sample surfaces. The immersion results indicated that pH values of the immersion medium increased with increasing AZ31 fiber contents. All the in vitro experimental results indicated that this new kind of magnesium alloy fibers reinforced PLGA composites show a potential for future biomedical applications.

关键词： Biomaterials Corrosion Polymeric composites AZ31 magnesium fiber

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF NOVEL 718 SUPERALLOy

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Acta Metallurgica Sinica(English Letters) 2006年第6期19卷 418-424页

作者： J.H.du X.D.Lü J.L.Qu Q.Deng J.y.Zhuang Z.y.Zhong Department of Superalloy Central Iron and Steel Research InstituteBeijing 100081China

Recently,a novel 718 superalloy with remarkable structural stability at 680℃has been designed and fabricated by CISRI(Central Iron and Steel Research Institute)*** identification of novel 718 alloy under the above-mentioned heat-treatment condition was performed using optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Results show that the novel 718 alloy has outstanding structural stability at 680℃.The novel 718alloy possess excellent structural stability and good mechanical properties,which is attributed to y-phase strengthening and also to the specific sandwich structure of theγ′+γ'strengthening phase.

关键词： novel 718 superalloy microstructure mechanical property stress rupture creep

Enantio-divergent C–H borylation with two different ligands from a single chiral source

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Science China Chemistry 2025年第01期 226-232页

作者： Rongrong du Senmiao Xu State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material TechnologyMinistry of Education Hangzhou Normal University University of Chinese Academy of Sciences

Reported here is an iridium-catalyzed enantio-divergent C（sp3）–H borylation of α-gem-dimethyl groups of trifluoromethyl ketone-derived hydrazones to construct a series of acyclic all-carbon quaternary stereocenters with a high level of chiral induction. Two different chiral bidentate boryl ligands from a common chiral source not only can switch the enantioselectivity but also are complementary in terms of the substrate scope.

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Analyzing and Mining Ordered Information Tables

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Journal of Computer Science & Technology 2003年第6期18卷 771-779页

作者：赛英 y.y.yao DepartmentofComputerInformationEngineering ShandongFinanceInstituteJinan250014P.R.China DepartmentofComputerScience UniversityofReginaReginaSaskatchewanS4SOA2Canada

Work in inductive learning has mostly been concentrated on classifying. However,there are many applications in which it is desirable to order rather than to classify instances. For modelling ordering problems, we generalize the notion of information tables to ordered information tables by adding order relations in attribute values. Then we propose a data analysis model by analyzing the dependency of attributes to describe the properties of ordered information *** problem of mining ordering rules is formulated as finding association between orderings of attribute values and the overall ordering of objects. An ordering rules may state that "if the value of an object x on an attribute a is ordered ahead of the value of another object y on the same attribute, then x is ordered ahead of y". For mining ordering rules, we first transform an ordered information table into a binary information table, and then apply any standard machine learning and data mining algorithms. As an illustration, we analyze in detail Maclean's universities ranking for the year 2000.

关键词： information tables learning ordering rules ranking rough sets

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第01期 174-180页

作者： Fan-Xiao Meng Xing-yu Wang Ka Lu Ju-Song yang Fu-Min Zhang Ai-Jun Ma Bao du yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

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