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第四届海内外青年设计与制造科学会议

作者： Joseph c.chen Iowa State University U.S.A.

＜正＞In this research,neural networks based surface recognition （NNSR） systems were developed in both milling and turning *** accelerometer and a proximity sensor were used to monitor the effect of vibration produced by the motions of the cutting tool and workpiece during the cutting *** backpropagation algorithm was employed as the learning method for the neural *** vibration signal and cutting parameters were inputs for the system,and the output is the prediction of surface roughness （Ra） during *** approach could judge surface roughness as accurately as stylus measurement techniques and provide surface roughness prediction without stopping the machine or removing the product from the production line.

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来源： cnki会议评论

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W＇-BOSON SEARcHES

chinese Physics c 2016年第10期40卷 609-612页

作者： M.-c. chen B.A. Dobrescu S. Willocq Uc Irvine Fermilab U Massachusetts

The W＇ boson is a massive hypothetical particle of spin 1 and electric charge ±1, which is a color singlet and is predicted in various extensions of the Standard Model （SM）.

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MORPHOLOGY AND ORIENTATION cHARAcTERISTIcS OF DIREcTIONALLY SOLIDIFIED α(A1)-Mg_2Si EUTEcTIc

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Acta Metallurgica Sinica(English Letters) 1996年第5期9卷 323-328页

作者： S.P.Li S.X.Zhao M.X Pan D.Q.Zhao X.c.chen Institute of Physics Chinese Academy of SciencesBeijing 100080China

Dependence of the morphology of α(Al)-Mg2Si eutectic on the solidification velocity, and its orientation characteristics were investigated by thermoanalysis, directional solidification and electron diffraction techniques in this *** eutectic morphology transformed from lamellae to rods with the increasing of the solidification velocity. Simultaneously, the orientation relationship changed from (100)Mg2Si/(100)Al;[110]Mg2si/[110]al to (011)Mg2si/(121)Al;[111]Mg2Si/[111]Al and (010)Mg2Si/(110)Al; [100]Mg2Si/[111]Al. Transformation of the eutectic morphology was related to the change of the preferred orientation of phase Mg2si.

关键词： ?Al)-Mg2Si eutectic orientation directional solidification

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Al_(80)Ni_6Y_8co_4cu_2 GLASS ALLOYS cONTAINING NANOScALEPARTIcLES BY ISOTHERMAL ANNEALING OR QUENcHING

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Acta Metallurgica Sinica(English Letters) 2000年第5期13卷 1039-1046页

作者： Z. Bian, G. He and G.L. chen (State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, china) J. Lu, D.J. chen, G.c. Tu, G.J. chen and X.J. Hu (Shougang Metallurgical Research Institute, Beijing Lab. for Adv. Metals and Mat. Univ. of Sci. and Technol. Beijing Beijing 100083 China Shougang Metall. Res. Inst. Beijing 100085 China

Al80Ni6 Y8 co4 cu2 amorphous ribbons were isothermally annealed and a mixed structure consisting of α-Al particle with a size of less than 15nm and Al3Ni compound with a size of about 30nm was obtained. The crystallization kinetics of Al80Ni6 Y8 co4 cu2 amorphous alloy shows that the precipitation of α-Al particles is the growth process controlled by diffusion of the solute elements rejected from the growing crystals. By quenching at different cooling rates, a mixed structure consisting of nanoscale α-Al particles and the remaining glass matrix or structure consisting of nanoscale particle (Al phase or Al3Ni compound) with a size of about 100nm was formed. The addition of co elements and cu elements to Al-Ni-Y alloy systems increases the glass formation ability of the alloy and the thermal stability of the supercooled liquid region against crystallization, which results from significant difference of atomic size, strong bonding nature among constituent elements and the low diffisivity of the solute elements due to the concentration gradient in the growing front of crystals.

关键词： a mixed structure nanoscale particle isothermal annealing cooling rate concentration gradient α-Al particle Al3Ni compound

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Mn-doped LiFePO_(4)@c as a high-performance cathode material for lithium-ion batteries

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Particuology 2024年第7期90卷 418-428页

作者： Wenjing chen Fangxiang Song Yumei Yang Qianlin chen School of chemistry and chemical Engineering Guizhou UniversityGuiyang550025China collaborative Innovation center of Guizhou Province for Efficient Utilization of Phosphorus and Fluorine Resources Guizhou UniversityGuiyang550025China

In this work,LiFe_(1-x)MnxPO_(4)@c(x=0,0.01,0.02,0.03)cathode materials were obtained by a simple co-precipitation method and heat treatment,and the influence of Mn-doped modification on the electrochemical performance of LiFePO_(4)@c cathode materials was *** show that by doping an appropriate amount of Mn,the cell volume became larger,and the electronic conductivity increased,which improved the Li+diffusion rate and thus its rate capability and cycle performance of Li-ion *** them,LiFe_(0.98)Mn_(0.02)PO_(4)@c showed superior lithium storage capability;the discharge capacity can reach 150.7 mAh g^(−1)at 0.1 *** cell could discharge up to 155.9 mAh g^(−1)at 1 c under high temperature at 45°c,which was higher than LiFePO_(4)@c(142 mAh g^(−1))under the same test *** discharge capacity of 1 c at room temperature was 139.9 mAh g^(−1),and the cycle stability was 95.9%after 200 *** showed that it had good rate capability and excellent cycle *** results indicate that Mn-doped LFP is a simple and effective strategy for developing high-performance cathode materials.

关键词： Mn-doped LiFePO_(4) Lithium-ion battery High temperature

Infectious keratitis in Vietnam:etiology,organisms,and management at Vietnam National Eye Hospital

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International Journal of Ophthalmology(English edition) 2022年第1期15卷 128-134页

作者： Pham Ngoc Dong Do Thi Thuy Hang Nguyen Thi Nga Duong Mai Thi Lien Angela c.chen Anthony J.Aldave Vietnam National Eye Hospital Hanoi 10000Vietnam Nam Dinh Eye Hospital Nam Dinh 420000Vietnam Stein Eye Institute UCLA David Geffen School of MedicineLos AngelesCA 90095USA

AIM:To report the etiologies,risk factors,treatments,and outcomes of infectious keratitis(IK)at a major Vietnamese eye ***:This is a retrospective review of all cases of IK at Vietnam National Eye Hospital(VNEH)in Hanoi,*** histories,demographics,clinical features,microbiological results,and treatment outcomes were ***:IK was diagnosed in 1974 eyes of 1952 patients,with ocular trauma being the greatest risk factor for IK(34.2%),frequently resulting from an agriculturerelated injur y(53.3%).The mean duration between symptom onset and presentation to VNEH was 19.3±14.4 d,and 98.7%of patients had been treated with topical antibiotic and/or antifungal agents prior to evaluation at *** on smear results of 1706 samples,the most common organisms identified were bacteria(n=1107,64.9%)and fungi(n=1092,64.0%),with identification of both bacteria and fungi in 614(36.0%)***-five of 374 bacterial cultures(14.7%)and 426 of 838 fungal cultures(50.8%)were positive,with the most commonly cultured pathogens being Pseudomonas aeruginosa,Streptococcus pneumonia,Fusarium spp.,and Aspergillus *** perforation and descemetocele developed in 391(19.8%)and 93(4.7%)eyes,*** treatment was successful in resolving IK in 50.4%eyes,while 337(17.1%)eyes underwent penetrating or anterior lamellar *** was performed in 7.1%of eyes,most commonly in the setting of fungal ***:Ocular trauma is a major risk factor for IK in Vietnam,which is diagnosed in almost 400 patients each year at *** this,and as approximately one quarter of the eyes that develop IK require corneal transplantation or evisceration,greater emphasis should be placed on the development of prevention and treatment programs for IK in Vietnam.

关键词： infectious keratitis bacterial keratitis fungal keratitis microsporidial keratitis Acanthamoeba keratitis herpes simplex virus keratitis Vietnam

Fe-N_(x) sites coupled with core-shell FeS@c nanoparticles to boost the oxygen catalysis for rechargeable Zn-air batteries

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Journal of Energy chemistry 2024年第3期90卷 565-577,I0013页

作者： Katam Srinivas Zhuo chen Anran chen Fei Ma Ming-qiang Zhu Yuanfu chen School of Integrated circuit Science and Engineering and State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054SichuanChina college of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100ShaanxiChina School of Materials and Energy Yunnan UniversityKunming 650091YunnanChina

The development of efficient single-atom catalysts(SAcs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic ***,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSc)coupled with FeS@c core-shell nanoparticles(FAS-NSc@950) is synthesized by a facile hydrothermal reaction and subsequent *** to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling ***,FAS-NSc@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/c(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/c-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSc@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/c-Ir/c-based *** work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SAcs for ORR,with potential implications for energy conversion and storage technologies.

关键词： Fe-N_(x)sites core-shell FeS@c Synergistic interactions Oxygen reduction reaction Zn-air battery

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Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators

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National Science Review 2024年第2期11卷 15-23页

作者： Rui chen Hai-Peng Sun Mingqiang Gu chun-Bo Hua Qihang Liu Hai-Zhou Lu X.c.Xie Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) International Quantum Academy Institute for Theoretical Physics and Astrophysics University of Würzburg School of Electronic and Information Engineering Hubei University of Science and Technology Guangdong Provincial Key Laboratory of computational Science and Material Design Southern University of Science and Technology Shenzhen Key Laboratory of Quantum Science and Engineering International center for Quantum Materials School of PhysicsPeking University collaborative Innovation center of Quantum Matter cAS center for Excellence in Topological Quantum computation University of Chinese Academy of Sciences

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

关键词： layerHall effect hidden Berry curvature antiferromagnetic insulator axion insulator, quantum transport

Eigenstate properties of the disordered Bose-Hubbard chain

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Frontiers of physics 2024年第4期19卷 57-72页

作者： Jie chen chun chen Xiaoqun Wang Key Laboratory of Artificial Structures and Quantum control(Ministry of Education) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China School of Physics Zhejiang UniversityHangzhou 310058China collaborative Innovation center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Many-body localization(MBL)of a disordered interacting boson system in one dimension is studied numerically at the filling faction *** von Neumann entanglement entropy Svn is commonly used to detect the MBL phase transition but remains challenging to be directly *** on the U(1)symmetry from the particle number conservation,Svn can be decomposed into the particle number entropy S_(n) and the configuration entropy *** light of the tendency that the eigenstate's S_(c) nears zero in the localized phase,we introduce a quantity describing the deviation of S from the ideal thermalization distribution;finite-size scaling analysis illustrates that it shares the same phase transition point with Sv but displays the better critical *** observation hints that the phase transition to MBL might largely be determined by S and its fluctuations Notably,the recent experiments[***,et al.,Science 364,256(2019);***,et al.,***.19,481(2023)]demonstrated that this deviation can potentially be measured through the Sn ***,our investigations reveal that the thermalized states primarily occupy the low-energy section of the spectrum,as indicated by measures of localization length,gap ratio,and energy density *** low-energy spectrum of the Bose model closely resembles the entire spectrum of the Fermi(or spin XXZ)model,accommodating a transition from the thermalized to the localized ***,owing to the bosonic statistics,the high-energy spectrum of the model allows the formation of distinct clusters of bosons in the random potential *** analyze the resulting eigenstate properties and briefly summarize the associated *** distinguish between the phase regions at the low and high energies,a probing quantity based on the structure of S_(VN) is also *** work highlights the importance of symmetry combined with entanglement in the study of *** this regard,for the disordered Heisenberg XXZ

关键词： entanglement entropy decomposition U(1)symmetry thermalization-to-localization transition