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Triple reverse order law for the Drazin inverse

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 55-68页

作者： wang hua ZHONG cheng-cheng College of Sciences Inner Mongolia University of TechnologyHohhot 010051China College of Engineering University of Jinan Quancheng CollegeYantai 265600China

In this paper,we investigate the reverse order law for Drazin inverse of three bound-ed linear operators under some commutation ***,the Drazin invertibility of sum is also obtained for two bounded linear operators and... 详细信息

关键词： Drazin inverse reverse order law space decomposition

Microstructure and property of laser additive manufactured alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si after aged at different temperatures

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Rare Metals 2024年第5期43卷 2275-2281页

作者： Guo-Chao Li Xu cheng hua-Ming wang National Engineering Laboratory of Additive Manufacturing for Large Metallic Components and Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for Large Metallic Components School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The solid solution and aging treatment for conventional manufacturing processes might not be suitable for laser additive manufactured titanium alloys due to the different lamellar *** this study,the influence of aging temperatures(600,700 and 800°C)on microstructure and mechanical properties of titanium alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si was *** results indicate that after solid solution treatment at 970°C followed by water quenching,the alloy mainly consists of coarsening lamellar a phase in martensite α' *** at 600°C will not change the size of primary lamellar α phase but lead to huge amount of secondary a phases(α_(s))generating with very fine *** increasing the aging temperature,the number of α_(s) decreases but with coarsened *** aged at 800°C,the width of the asphase reaches 350 nm,almost 7 times wider than that aged at 600°*** changing size of α_(s) obviously influences the property of the *** fine α_(s) leads to high strength and microhardness but low plasticity,and specimen aged at 700°C with suitable assize has the best comprehensive properties.

关键词： α+βtitanium alloy Laser additive manufacturing Solid solution and aging treatment Microstructure Room temperature tensile property

The trend of the APRGP velocity field and plates movement derived from GPS data

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Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 767-772页

作者： cheng PengFei , wang hua, cheng YingYan, WEN HanJiang & CAI YanHui Chinese Academy of Surveying and Mapping, Beijing 100039, China Chinese Academy of Surveying and Mapping Beijing China (GRID:grid.464302.7) (ISNI:***)

High-precision data processing theories and methods for the wide area GPS network–––Asia Pacific Regional Geodesy Project (APRGP), are systematically discussed in this article. With the software bernese5.0 update, the annual results of APRGP coordinate, velocity field and the trend of plate movement are reestimated, and the corresponding accuracy of adjustment with different constraints, also the velocity field of APRGP, are presented and analyzed. Conclusions could be drawn that Eurasian plate (EURA) rotates clockwise, the Australian plate (AUST) and the Indian plate (INDI) move from southwest to northeast, while the Pacific plate (PCFC) is drifting to northwest, which shows agreement with those of IGS results.

关键词： APRGP Bernese5.0 GPS Data processing velocity field plate movement

Measurement of electric properties of the single supersaturated aerosol droplet

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Chinese Science Bulletin 2008年第11期53卷 1773-1776页

作者： HE KeJuan cheng hua ZHU YanYing wang LiangYu ZHANG YunHong Institute for Chemical Physics School of Science Beijing Institute of Technology Beijing 100081 China

A system for measuring the electric properties of single aerosol droplet is designed and applied to the NaClO4 aerosol droplet in different relative humidity (RH). The conductance and capacitance are ob-tained within the whole RH range, especially in the supersaturated state which cannot be acquired from the bulk solution. These results reflect the situation of ions in the droplet macroscopically and supply useful information for other relative study fields, such as crystallogeny and aerography.

关键词：过饱和气溶胶液滴介电性能测量方法大气科学

A high torque dual 3-phase permanent magnet vernier machine with strong fault-tolerance

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Science China Technological Sciences 2024年第10期67卷 3275-3284页

作者： XU YuWen wang Bo wang RongXin cheng Ming hua Wei School of Electrical Engineering Southeast University

The field modulation effect has been proposed and investigated in various electric machine topologies. Among them, permanent magnet vernier machines(PMVMs) have attained intensive research due to the high torque density and simple ***, the performance of PMVMs in terms of fault tolerance is seldom mentioned. This article proposes a novel dual 3-phase fault-tolerant PMVM with segregated concentric windings. Benefiting from the field modulation effect, the PMVM can generate high torque with low PM flux. The low PM flux also implies small fault currents in the short-circuit case. Therefore, the PMVM exhibits inherent good fault-tolerant capability without sacrificing torque performance. Two independent 3-phase modular winding sets are adopted to improve redundancy. To realize the physical and electrical isolation, each winding set is controlled by a standard 3-phase inverter. The healthy performance and fault tolerance of the proposed machine are evaluated by finite element analysis and verified by experimental tests. The results infer its advantages in healthy conditions and various fault scenarios,including open-circuit, short-circuit, and interturn short-circuit conditions.

关键词： fault-tolerant capability segregated windings field modulation permanent magnet vernier machine

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Facile synthesis of La_2Mo_2O_9 nanoparticles via an EDTA complexing approach

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Rare Metals 2008年第4期27卷 340-344页

作者： cheng hua wang Hongen LI Liang LU Zhouguang QIAN Dong College of Chemistry and Chemical Engineering Central South University Changsha 410083 China State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China

A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.

关键词： inorganic non-metal materials EDTA complexing sol-gel La2Mo2O9 nanoparticles porous structure

Convergence analysis for complementary-label learning with kernel ridge regression

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Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 533-544页

作者： NIE Wei-lin wang cheng XIE Zhong-hua School of Mathematics and Statistics Huizhou UniversityHuizhou 516007China School of Computer Science and Engineering Huizhou UniversityHuizhou 516007China

Complementary-label learning(CLL)aims at finding a classifier via samples with complementary *** data is considered to contain less information than ordinary-label *** transition matrix between the true label and the complementary label,and some loss functions have been developed to handle this *** this paper,we show that CLL can be transformed into ordinary classification under some mild conditions,which indicates that the complementary labels can supply enough information in most *** an example,an extensive misclassification error analysis was performed for the Kernel Ridge Regression(KRR)method applied to multiple complementary-label learning(MCLL),which demonstrates its superior performance compared to existing approaches.

关键词： multiple complementary-label learning partial label learning error analysis reproducing kernel Hilbert spaces

Reliability of a Multicomponent Stress-strength Model Based on a Bivariate Kumaraswamy Distribution with Censored Data

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 478-507页

作者： Cong-hua cheng School of Mathematics and Statistics Zhaoqing UniversityZhaoqing 526061China

In this paper,we consider a system which has k statistically independent and identically distributed strength components and each component is constructed by a pair of statistically dependent elements with doubly type-II censored *** elements(X1,Y1),(X2,Y2),…,(Xk,Yk)follow a bivariate Kumaraswamy distribution and each element is exposed to a common random stress T which follows a Kumaraswamy *** system is regarded as operating only if at least s out of k(1≤s≤k)strength variables exceed the random *** multicomponent reliability of the system is given by Rs,k=P(at least s of the(Z1,…,Zk)exceed T)where Zi=min(Xi,Yi),i=1,…,*** Bayes estimates of Rs,k have been developed by using the Markov Chain Monte Carlo methods due to the lack of explicit *** uniformly minimum variance unbiased and exact Bayes estimates of Rs,k are obtained analytically when the common second shape parameter is *** asymptotic confidence interval and the highest probability density credible interval are constructed for Rs,*** reliability estimators are compared by using the estimated risks through Monte Carlo simulations.

关键词： stress-strength model bivariate Kumaraswamy distribution multicomponent reliability doubly Type-II censored scheme interval estimation

An Optimization Technique for PMF Estimation in Approximate Circuits

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Journal of Computer Science & Technology 2023年第2期38卷 289-297页

作者：窦昱钦王成华 College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106 China

As an emerging computing technology,approximate computing enables computing systems to utilize hardware resources ***,approximate arithmetic units have received extensive attention and have been employed as hardware modules to build approximate circuit systems,such as approximate *** order to make the approximate circuit system meet the application requirements,it is imperative to quickly estimate the error quality caused by the approximate unit,especially in the high-level synthesis of the approximate ***,there are few studies in the literature on how to efficiently evaluate the errors in the approximate circuit ***,this paper focuses on error evaluation techniques for circuit systems consisting of approximate adders and approximate multipliers,which are the key hardware components in fault-tolerant *** this paper,the characteristics of probability mass function(PMF)based estimation are analyzed initially,and then an optimization technique for PMF-based estimation is proposed with consideration of these ***,experiments prove that the optimization technology can reduce the time required for PMF-based estimation and improve the estimation quality.

关键词： approximate circuit error quality estimate probability mass function(PMF)estimation architecture level