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Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 134-141页

作者：许楠 LIU Lutao SONG Qining ZHAO Jianhua bao Yefeng College of Materials Science and Engineering Hohai UniversityChangzhou 213200China

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

关键词： aluminum alloy friction stir welding recrystallization microstructure mechanical properties

Temperature-controlled DCP Fluorescent Probe Based on Hydrogel-immobilized Quantum Dots Composite

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 931-936页

作者：童伊琳杨坤 HAN Xuecai YU Kan bao Jiaqi Faculty Information Science and Technology Wenhua CollegeWuhan 430074China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430074China Yangtze Optical Fibre and Cable Joint Stock Limited Company Wuhan 430074China

A composite was created by incorporating the quantum dot-enhanced SiO_(2)nanoparticles within this *** on this composite,a temperature-controlled fluorescent probe for DCP was developed.A meticulous examination of this probe revealed its attributes and factors affecting its *** using temperature modulation,the probe was adept at detecting DCP concentrations ranging between 1.0×10^(-6)and 9.0×10^(-6)mol/*** a probe offers remarkable selectivity,repeatability,and robust stability,so that the detection of DCP can be carried out at different temperatures,and a fast,reliable,sensitive and low-cost intelligent detection method is realized.

关键词： temperature-controlled fluorescent probe hydrogel-immobilized quantum dots composite DCP

Convergence of Hyperbolic Neural Networks Under Riemannian Stochastic Gradient Descent

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1175-1188页

作者： Wes Whiting bao Wang Jack Xin Department of Mathematics University of CaliforniaIrvineCAUSA Department of Mathematics Scientific Computing and Imaging InstituteUniversity of UtahSalt Lake CityUTUSA

We prove,under mild conditions,the convergence of a Riemannian gradient descent method for a hyperbolic neural network regression model,both in batch gradient descent and stochastic gradient *** also discuss a Riemann... 详细信息

关键词： Hyperbolic neural network Riemannian gradient descent Riemannian Adam(RAdam) Training convergence

Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China

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Advances in Atmospheric Sciences 2024年第1期41卷 73-83页

作者： Xiuping YAO Ruoying LI Xiaohong bao Qiaohua LIU China Meteorological Administration Training Centre Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China College of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July *** on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance *** showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to *** particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 ***,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase *** meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in *** transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR.

关键词： extreme torrential rain rotational kinetic energy kinetic energy generation and transport barotropic process

Aptamer-Based Antibiotic Electrochemical Detection Platform Using Portable Plastic Gold Electrode and Multichannel Chip

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Chinese Journal of Chemistry 2024年第2期42卷 171-176页

作者： Yin bao Kaiwei Cai Yichen Liu Bingling Li Changchun Institute of Applied Chemistry Chinese Academy of SciencesChangchunJilin 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefeiAnhui 230026China

The development of accurate,rapid and practical electrochemical sensing technology for antibiotic detection has an important application prospect in many fields such as food safety,environmental monitoring,medical and health *** this research,kanamycin specific DNA aptamer and its partially complementary short chain were self-assembled onto the surface of an integrated portable plastic gold electrode(PGE)by Au-s bond,and a simple kanamycin electrochemical biosensor interface was *** the same time,the epoxy resin channel layer was designed,and the auxiliary instrument was set up independently in the laboratory,which could help to measure and analyze eight groups of samples automatically in *** quantitative analysis results showed that in 20 min,the sensor had a good linear relationship between the peak current change of square wave voltammetry and the negative logarithm of kanamycin concentration when kanamycin concentration was in the range of 1-10o0μmol/L,and the detection limit could reach 0.40μmol/*** addition,the discrimination could be achieved within 5 min in the real-time analysis *** sensor had a simple construction method,good selectivity and stability,and could be used for rapid or real-time detection of kanamycin residues in actual water samples,which provided a new direction for the practical detection of kanamycin in environmental watersamples.

关键词： Biosensor Aptamer Antibiotics Electroanalysis DNA

Identifying the best common factor model via exploratory eactor analysis

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 24-33页

作者： HE bao-hua TANG Rui TAGN Qi-yi School of Big Data Fuzhou University of International Studies and TradeFuzhou 350202China School of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China Department of Computer Science University of BathUK Institute of Insect Science Zhejiang UniversityHangzhou 310058China.

Currently,there is no solid criterion for judging the quality of the estimators in factor *** paper presents a new evaluation method for exploratory factor analysis that pinpoints an appropriate number of factors along with the best method for factor *** proposed technique consists of two steps:testing the normality of the residuals from the fitted model via the Shapiro-Wilk test and using an empirical quantified index to judge the quality of the factor *** are presented to demonstrate how the method is implemented and to verify its effectiveness.

关键词： factor analysis Shapiro-Wilk normality residuals

d-Orbital steered FeN_(4)moiety through N,S dual-site adjustation for zinc-air flow battery

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Journal of Energy Chemistry 2024年第5期92卷 8-15页

作者： Chunzhu bao Mingwei Tong Xueli Li Zhonghua Xiang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The implementation of pristine covalent organic polymer(CO_(2)P)with well-defined structure as air electrode may spark fresh vitality to rechargeable zinc-air flow batteries(ZAFBs),but it still remains challenges in synergistically regulating their electronic states and structural porosity for the great device ***,we conquer these issues by exploiting N and S co-doped graphene with COP rich in metal-ligand nitrogen to synergistically construct an effective catalyst for oxygen reduction reaction(ORR).Among them,the N and S co-doped sites with high electronegativity properties alter the number of electron occupations in the d orbital of the iron centre and form electron-transfer bridges,thereby boosting the selectivity of the ORR-catalysed four-electron ***,the introduction of COP materials aids the formation of pore interstices in the graphene lamellae,which both adequately expose the active sites and facilitate the transport of reactive *** from the synergistic effect,as-prepared catalyst exhibits excellent half-wave potentials(E_(1/2)=912 mV)and stability(merely 8.8%drop after a long-term durability test of 50000 s).Further,ZAFBs assembled with the N/SG@CO_(2)P catalyst demonstrate exceptional power density(163.8 mW cm^(-2))and continuous charge and discharge for approximately 140 h at 10 mA cm^(-2),outperforming the noble-metal benchmarks.

关键词： Nitrogen/sulfurdual sites Metal-coordinated nitrogen sites Covalent organic polymer Oxygen reduction reaction Zn-airflow battery

General Method of Combining Grover and Simon for Attacking Block Ciphers

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China Communications 2024年第6期21卷 237-245页

作者： Fu Xiangqun bao Wansu Shi Jianhong Li Tan Henan Key Laboratory of Quantum Information and Cryptography PLA SSF IEUZhengzhou 450001China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

The compatibility of different quantum algorithms should be considered when these algorithms are *** this paper,the method of combining Grover and Simon is studied for the first time,under some preconditions or ***,we give two preconditions of applying Grover’s algorithm,which ensure that the success probability of finding the marked element is close to ***,based on these two preconditions,it is found out that the success probability of the quantum algorithm for FXconstruction is far less than ***,we give the design method of the Oracle function,and then present the general method of combining Grover and Simon algorithm for attacking block ciphers,with success probability close to 1.

关键词： block ciphers post-quantum crypto quantum algorithms

Module Structures on U(ε^(-))for the Euclidean Algebra

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Algebra Colloquium 2024年第1期31卷 49-56页

作者： Yixin bao Yan'an Cai School of Sciences Harbin Institute of Technology ShenzhenGuangdong 518055China Department of Mathematics Soochow University SuzhouJiangsu 215006China

We classify modules which are free of rank 1 when restricted to the negative part for the Euclidean Lie *** and necessary conditions for the simplicity of these modules are *** these modules we construct modules which... 详细信息

关键词： Euclidean algebra free module simple module nonweight module