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M_(φ)-type Submodules over the Bidisk

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Acta Mathematica Sinica,English Series 2021年第5期37卷 805-824页

作者： Guo Zeng YANG chang hui wu Tao YU School of Mathematics and Statistics Zhengzhou Normal UniversityZhengzhou 450044P.R.China School of Mathematical Sciences Qufu Normal UniversityQufu 273165P.R.China School of Mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China

Let H^(2)(D^(2))be the Hardy space over the bidisk D^(2),and let M_(φ)=[(z-φ(w))^(2)]be the submodule generated by(z-φ(w))^(2),whereφ(w)is a function in H∞(w).The related quotient module is denoted by N_(φ)=H^(2)(D^(2))ΘM_(φ).In the present paper,we study the Fredholmness of compression operators S_(z),S_(w) on N_(φ).Whenφ(w)is a nonconstant inner function,we prove that the Beurling type theorem holds for the fringe operator F_(w) on[(z-w)^(2)]Θz[(z-w)^(2)]and the Beurling type theorem holds for the fringe operator Fz on M_(φ)ΘwM_(φ)ifφ(0)=***,we study some properties of F_(w) on[(z-w^(2))^(2)]Θz[(z-w^(2))^(2)].

关键词： Submodules Beurling type theorem compression operators Fredholmness

Beurling Type Theorem on the Hilbert Space Generated by a Positive Sequence

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Acta Mathematica Sinica,English Series 2019年第9期35卷 1511-1519页

作者： chang hui wu Zhi Jie WANG Tao YU School of Mathematical Sciences Dalian University of Technology Dalian 116024 P. R. China Department of Mathematics Physics and Information Engineering Jiaxing University Jiaxing 314001 P. R. China

Let H^2(γ) be the Hilbert space over the bidisk D^2 generated by a positive sequence γ={γnm}n,m≥0. In this paper, we prove that the Beurling type theorem holds for the shift operator on H^2(γ) with γ={γnm}n,m≥0 satisfying certain series of inequalities. As a corollary, we give several applications to a class of classical analytic reproducing kernel Hilbert spaces over the bidisk D^2.

关键词： Beurling type theorem invariant subspace wandering subspace

Comparison between oxide-reduced and water-atomized copper powders used in making sintered wicks of heat pipe

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China Particuology 2007年第3期5卷 220-224页

作者： Liu-Ho Chiu chang-hui wu Pee-Yew Lee Department of Materials Engineering Tatung University Taipei 10451 Taiwan China Institute of Materials Engineering Taiwan Ocean University Keelung Taiwan China

Oxide-reduced copper powder can be produced efficiently at low cost. The volume shrinkage, porosity, maximum pore size, permeability and thermal conductivity of wicks sintered from two oxide-reduced （OR） powders were compared with one from water-atomized （WA） powder. The green specimens were sintered at temperatures from 800 to 1000 ℃ in a tube furnace under a reduction stream of 10% hydrogen and 90% argon. The results show that the property variations of OR - 100 and WA wicks due to porosity changes have a similar tendency and range. Nine hundred degree celsius is a recommended sintering temperature for producing ideal wicks for use in heat pipes. A smaller maximum pore size can be obtained by increasing the green density.2007 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.

关键词： Sintered wick Copper powder Porous property Oxide-reduced powder

Microstructures and properties evolution of Al-Zn-Mg-Cu alloy under electrical pulse assisted creep aging

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Advances in Manufacturing 2022年第4期10卷 596-609页

作者： Tian-Jun Bian Heng Li Chao Lei chang-hui wu Li-Wen Zhang State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China School of Materials Science and Engineering Xi’an University of TechnologyXi’an710048People’s Republic of China

Creep aging(CA)is a promising forming technology for integral panels with complex ***,how to balance excellent corrosion resistance and strength is still a challenge for CA *** synchronously applying electrical pulse(300 Hz,15 A/mm^(2))in the middle of steady-state CA of Al-Zn-Mg-Cu alloy,the electrically assisted CA(ECA)is proposed to induce retrogression rapidly for realizing a three-step aging(retrogression and re-aging,RRA)in CA to tailor the needed properties *** is compared with conventional CA with one-step aging(peak aging,T6 or over aging,T7),two-step aging(over aging,T73)and RRA in hardness,intergranular corrosion and *** the ECA of pre-aging and re-aging for 20 h plus electropulsing for 10 min,the hardness is 10.5%,20.5%and 18.9%higher than those of CA with T6,T7 and T73 processes,respectively,while the corrosion resistance is higher than T6 process and lower than T7 and T73 *** the hardness and corrosion resistance are comparable to those of the CA with the RRA process,ECA takes one hour less due to the accelerated effect of the electropulsing and is not limited by the thick *** improved comprehensive performance of the ECA sample is due to both fine intragranular precipitatesη′and large discontinuous grain boundary precipitatesη.

关键词： Creep aging(CA) Electrical pulse Retrogression Corrosion Hardness Al-Zn-Mg-Cu alloy

Multifunctional carbon materials from rugose rose for energy storage and water purification

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 1-13页

作者： Peng-hui Li hui Zhou Wen-Juan wu Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China College of Light Industry and Food Engineering Nanjing Forestry UniversityNanjing 210037China College of Chemical Engineering East China University of Science and TechnologyShanghai 200237China State Key Laboratory of Chemical Engineering Shanghai 200237China

With the advancement of social process,the resource problem is becoming more prominent,biomass materials come into being,and it is becoming more and more important to explore and prepare efficient and multifunctional biomass materials to alleviate the problems of energy storage and water *** this paper,nitrogen-doped hierarchical porous carbon materials(NRRC)were produced by one-step carbonization of withered rose as raw material and melamine as nitrogen source with KOH-activated *** resulting nitrogen-doped porous carbon material had the most abundant pores and the best microspherical graded pore structure,with a specific surface area of up to 1393 m2·g^(-1),a pore volume of 0.68 cm3·g^(-1),and a nitrogen-doped content of 5.52%.Electrochemical tests showed that the maximum specific capacitance of NRRC in the three-electrode system was 346.4 F·g^(-1)(0.5 A·g^(-1)),which was combined with favorable capacitance retention performance and cycling *** NRRC//NRRC symmetric supercapacitors were further assembled,and the maximum energy density of a single device was 23.88 Wh·kg^(-1),which still maintains excellent capacitance retention and cyclic charging/discharging *** example,the capacitance retention rate was always close to 96.27%with almost negligible capacitance loss after 10000 consecutive charge/discharge cycles(current density:10 A·g^(-1)).Regardless of the three-electrode or two-electrode system,the super capacitive performance of NRRC porous carbon materials was comparable to the electrochemical performance of many reported biomass porous carbon materials,which showed better energy storage advantages and practical application *** addition,NRRC porous carbon materials had excellent water purification *** dye adsorption test confirmed that NRRC had a high adsorption capacity(491.47 mg·g^(-1))for methylene *** undoubtedly also showed a potential and promising avenue for high value-added utilization

关键词： rose carbon adsorption electrode material electrochemical performance

Principal components of nuclear mass models

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： Xin-hui wu Pengwei Zhao Department of Physics Fuzhou UniversityFuzhou 350108China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

Anomalous response to creep deformation from dislocation density during electrically assisted creep aging

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Rare Metals 2024年第10期43卷 5268-5283页

作者： chang Zhou Li-Hua Zhan Chun-hui Liu Ming-hui Huang College of Mechanical and Electrical Engineering Central South University Light Alloys Research Institute State Key Laboratory of Precision Manufacturing for Extreme Service PerformanceCentral South University

Adding numerous dislocations into metallic materials before the forming stage significantly enhances their deformability. However, this beneficial effect of dislocation defects may not have a simple monotonic relationship with increased dislocation density during electroplastic deformation. This is due to the complex interactions among the drifting electrons, dislocations and solute atoms. This study explores the effect of diverse initial dislocation densities on creep deformation during electrically aided creep aging of an aluminum–lithium alloy. Surprisingly, we discovered a threshold value for the dislocation density that affects electroplastic creep, i.e., an enhanced effect from dislocations weakens when exceeding this density threshold(an anomalous response to creep). Microstructural data also reveal that such an anomalous response originates mainly from differences in various dislocation density-tailored configurations, which can influence the dislocation motions and precipitation kinetics of the strengthening T1precipitates under the same action of pulsed currents. This study provides important insights into the dislocation density-mediated electroplastic creep of an aluminum–lithium alloy.

关键词： Al–Cu–Li alloy Creep aging Dislocation density Pulsed currents

Crossed renal ectopia with rectal cancer:A case report

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World Journal of Clinical Cases 2024年第12期12卷 2122-2127页

作者： Zhen-Wei Tang hui-Feng Yang Zhao-Yu wu chang-You Wang Department of General Surgery North China University of Science and Technology Affiliated HospitalTangshan 063000Hebei ProvinceChina

BACKGROUND Crossed renal ectopia(CRE)occurs when one kidney crosses the midline from the primary side to the contralateral side while the ureter remains on the primary *** cancer,one of the most common malignant tumors of the digestive tract,refers to cancer from the dentate line to the rectosigmoid *** concurrent presentation of CRE alongside rectal cancer is an uncommon clinical *** SUMMARY Herein,we report a 69-year-old male patient with rectal cancer who was diagnosed with CRE via computed tomography during *** thorough preoperative evaluations,the patient underwent Dixon *** We performed laparoscopic radical resection of rectal cancer and adequate lymph node removal in a patient with CRE with no postoperative discomfort.

关键词： Rectal cancer Crossed renal ectopia Anatomy Laparoscopic surgery Case report

Applying an Improved Dung Beetle Optimizer Algorithm to Network Traffic Identification

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Computers, Materials & Continua 2024年第3期78卷 4091-4107页

作者： Qinyue wu hui Xu Mengran Liu School of Computer Science Hubei University of TechnologyWuhan430068China

Network traffic identification is critical for maintaining network security and further meeting various demands of network ***,network traffic data typically possesses high dimensionality and complexity,leading to practical problems in traffic identification data *** the original Dung Beetle Optimizer(DBO)algorithm,Grey Wolf Optimization(GWO)algorithm,Whale Optimization Algorithm(WOA),and Particle Swarm Optimization(PSO)algorithm have the shortcomings of slow convergence and easily fall into the local optimal solution,an Improved Dung Beetle Optimizer(IDBO)algorithm is proposed for network traffic ***,the Sobol sequence is utilized to initialize the dung beetle population,laying the foundation for finding the global optimal ***,an integration of levy flight and golden sine strategy is suggested to give dung beetles a greater probability of exploring unvisited areas,escaping from the local optimal solution,and converging more effectively towards a global optimal ***,an adaptive weight factor is utilized to enhance the search capabilities of the original DBO algorithm and accelerate *** the improvements above,the proposed IDBO algorithm is then applied to traffic identification data analytics and feature selection,as so to find the optimal subset for K-Nearest Neighbor(KNN)*** simulation experiments use the CICIDS2017 dataset to verify the effectiveness of the proposed IDBO algorithm and compare it with the original DBO,GWO,WOA,and PSO *** experimental results show that,compared with other algorithms,the accuracy and recall are improved by 1.53%and 0.88%in binary classification,and the Distributed Denial of Service(DDoS)class identification is the most effective in multi-classification,with an improvement of 5.80%and 0.33%for accuracy and recall,***,the proposed IDBO algorithm is effective in increasing the efficiency of traffic identificati

关键词： Network security network traffic identification data analytics feature selection dung beetle optimizer