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Semisolid die forging process,microstructures and properties of AZ31 magnesium alloy mobile telephone shells

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 665-670页

作者： ren-guo Guan Li-qing Chen fu-rong Cao Zhan-yong Zhao Yong ren College of Materials and Metallurgy Northeastern University Shenyang 110004 China State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 China

A semisolid slurry of AZ31 magnesium alloy was prepared by vibrating wavelike sloping plate process,and the semisolid die forging process,microstructures,and properties of the magnesium alloy mobile telephone shell were *** semisolid forging process was performed on a YA32-315 four-column universal hydraulic *** microstructures were observed by optical microscopy,the hardness was analyzed with a model 450SVD Vickers hardometer,the mechanical properties was measured with a CMT5105 tensile test machine,and the fractograph of elongated specimens was observed by scanning electron microscopy （SEM）.The results reveal that with the increase of die forging force,the microstructures of the product become fine and dense.A lower preheating temperature and a longer dwell time are favorable to the formation of fine and dense *** optimum process conditions of preparing mobile telephone shells with excellent surface quality and microstructures are a die forging force of 2000 kN,a die preheating temperature of 250℃,and a dwell time of 240 *** solution treatment at 430℃ and aging at 220℃ for 8 h,the Vickers hardness is 61.7 and the ultimate tensile strength of the product is *** fractographs show the mixing mechanisms of quasi-cleavage fracture and ductile fracture.

关键词： magnesium alloys semisolid forging microstructure mechanical properties fracture

Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process:Experimental and theoretical study

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Journal of Environmental Sciences 2024年第8期142卷 103-114页

作者： Xiang tu Yunsong Bai Qing fu Sheng Chang Kunfeng Zhang Yang Pan Ruiyang Xiao Yifu fu Qi Zhang State Key Laboratory of Environmental Criteria and Risk Assessment State Environmental Protection Key Laboratory of Drinking Water Source ProtectionResearch Centre of Lake EnvironmentNational Engineering Laboratory for Lake Pollution Control and Ecological RestorationChinese Research Academy of Environmental SciencesBeijing 100012China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Institute of Environmental Engineering School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China School of Forestry Northeast Forestry UniversityHarbin 150040China

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone(NMT)and its major metabolite 6-methoxy-2-naphthylacetic acid(MNA)in the coupling process of ultraviolet and monochloramine(UV/NH2Cl).The second-order rate constants of the contaminants reacting with reactive radicals(HO·,Cl·,Cl_(2)·-,and CO_(3)·^(-))were determined by laser flash photolysis ***·and Cl·contributed predominantly with 52.3%and 21.7%for NMT degradation and 60.8%and 22.3%for MNA *** presence of chlorides retarded the degradation of NMT,while promoted the destruction of MNA,which was ascribed to the photosensitization effects of MNA under UV *** functional theory(DFT)calculations revealed that radical adduct formation(RAF)was dominant pathway for both HO·and Cl·reacting with the contaminants,and hydrogen atom transfer(HAT)preferred to occur on side chains of NMT and *** reacted with NO_(2)·through single electron transfer(SET)with the second-order rate constant calculated to be 5.35×10^(7)(mol/L)^(-1)sec^(-1),and the contribution of NO_(2)·was predicted to be 13.0%of the total rate constant of NMT in pure water,which indicated that NO_(2)·played a nonnegligible role in the degradation of *** acute toxicity and developmental toxicity of NMT were enhanced after UV/NH_(2)Cl treatment,while those of MNA were *** transformation products of both NMT and MNA exhibited higher mutagenicity than their parent *** study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

关键词： UV/NH_(2)Cl Reactive species Degradation kinetics Reaction mechanism Degradation products

Prediction of column failure modes based on artificial neural network

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 481-493页

作者： Wan Haitao Qi Yongle Zhao Tiejun ren Wenjuan fu Xiaoyan School of Civil Engineering and Architecture Henan UniversityKaifeng 475001China China Energy Engineering Group Guangdong Electric Power Design Institute Co. Ltd.Guangzhou 510663China

To implement the performance-based seismic design of engineered structures,the failure modes of members must be *** classification method of column failure modes is analyzed using data from the Pacific Earthquake Engineering Research Center(PEER).The main factors affecting failure modes of columns include the hoop ratios,longitudinal reinforcement ratios,ratios of transverse reinforcement spacing to section depth,aspect ratios,axial compression ratios,and flexure-shear *** study proposes a data-driven prediction model based on an artificial neural network(ANN)to identify the column failure *** this study,111 groups of data are used,out of which 89 are used as training data and 22 are used as test data,and the ANN prediction model of failure modes is *** results show that the proposed method based on ANN is superior to traditional methods in identifying the column failure modes.

关键词： performance-based seismic design failure mode column artificial neural network prediction model

Facile Synthesis of SnO_2 Nanotube Arrays by Using ZnO Nanorod Arrays as Sacrificial Templates

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Journal of Materials Science & Technology 2013年第11期29卷 1053-1058页

作者： Yafang tu Qiuming fu Xiaojuan Niu Jianping Sang Zhijie Tan Xianwu Zou Department of Physics Institute for Interdisciplinary ResearchJianghan University School of Materials Science and Engineering Wuhan Institute of Technology Department of Physics Wuhan University

SnO2 nanotube arrays have been synthesized by means of a simple and low-cost method. The ZnO nanorod arrays prepared by aqueous chemical growth method were used as templates. By liquid phase deposition, SnO2 nanotubes were obtained with proper deposition time. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction were used to characterize the morphologies and structures of the products, and the formation mechanism was discussed according to the experimental results.

关键词： Nanostructure Zinc oxide Tin oxide

Blind Wideband Beamforming Algorithm Based on the Uncertainty Set

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Journal of Geodesy and Geoinformation Science 2021年第2期4卷 72-78页

作者： Chao ren Zhengxuan ZHANG Enyuan tu BDStar Navigation Co. Ltd.Beijing 100094China

Without prior knowledge,the steering vector estimation error of the desired signal will deteriorate the beamforming performance to some *** solve this problem,a space-time blind wideband beamforming algorithm based on the uncertainty set is *** of all,based on the space-time filtering model,the spherical constraint set is designed according to the uncertainty of the estimation error of the space-time steering ***,the method of wideband beamforming under multiconstraints in the frequency domain is derived,and the calculation of parameters of steering vector estimation error and loading factor are given in ***,a blind broadband beamforming algorithm combined with the CAB algorithm is *** improvement of the output signal-to-noise ratio is quantitatively analyzed by computer simulation to verify the correctness and robustness of the algorithm.

关键词： Space-time Adaptive Filtering(STAP) CAB blind wideband beamforming uncertainty set constraints

Formation of Carbon Nitride Films by Nitrogen Ion Bombardment on C_(60) Films

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Chinese Physics Letters 1996年第9期13卷 714-717页

作者： ren Zhong-min DU Yuan-cheng YING Zhi-feng LI fu-ming LIN Jing ren Yun-Zhu ZONG Xiang-fu Department of Physics Fudan UniversityState Key Joint Laboratory for Materials Modification by LaserIonand Electron BeamsShanghai 200433 Institute of Materials Science Fudan UniversityShanghai 200433

The synthesis of covalent carbon nitride films becomes an important subject in the materials research *** a new synthetic method two low-energy(400 and 1000eV)nitrogen ion beams are used to bombard on C_(60) thin films *** bombarded films are used for Raman and x-ray photoelectron spectroscopy(XPS)*** results of the analyses show that under the bombardment of 400eV nitrogen ion beam,the film still contains a large amount of undestructed C_(60) *** the case of l000eV bombardment,only a little amount of C_(60) molecules is kept *** experimental results also show that the destructed carbon species will combine chemically with nitrogen ions to form stable covalent carbon nitride,confirmed by the Raman peaks of,e.g.,*** XPS Nls and Cls lines also indicate the formation of covalent carbon nitride in the bombarded films.

关键词： field carbon chemically

Analyticity of Mild Solution for the 3D Incompressible Magneto-hydrodynamics Equations in Critical Spaces

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Acta Mathematica Sinica,English Series 2018年第11期34卷 1731-1741页

作者： Sheng WANG Yu Bing ren fu Yi XU School of Mathematics and Statistics Shandong University Weihai 264200 P. R. China School of Mathematics and Statistics Shandong University of Technology Zibo 255049 P. R. China

The Cauchy problem for the 3D incompressible magneto-hydrodynamics equations in crit- cal spaces is considered. We first prove the global well-posedness of mild solution for the system in some time dependent spaces. F... 详细信息

关键词： Lobal well-posedness analyticity mild solutions 3D incompressible magneto-hydrody- namics equations

Ion-Beam Bombarding Effects on Deposition of Carbon Nitride Films by Laser Ablation

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Chinese Physics Letters 1996年第11期13卷 878-880页

作者： YING Zhi-feng ren Zhong-min DU Yuan-cheng LI fu-ming LIN Jing ren Yun-zhu ZONG Xiang-fu Department of Physics and State Key Lab oratory for Materials Modification by LaserIon and Electron beamsFudan UniversityShanghai 200433 Institute of Materials Science Fudan UniversityShanghai 200433

In order to obtain high quality carbon nitride films,x-ray photoelectron spectroscopy and Raman spectrum were used to analyze several kinds of film:(a)laser-ablated amorphous carbon(a-C)films,(b)a-C films after a 1 keV nitrbgen ion beam bombardment.(c)carbon nitride(CN_(x))films synthesized by ablation assisted with ion beam bombardment,(d)CN_(x) films after a 50eV nitrogen ion beam bombardment,and(e)CN_(x) films after a 1 keV nitrogen ion beam *** comparison among these films showed that the concurrent deposition of CN_(x) films by ablation and a nitrogen ion beam should be better than the post-treatment of a-C films by nitrogen ion beam *** the case of concurrent deposited CN_(x) films,a post-treatment by a nitrogen ion beam bombardment with an appropriate energy(possibly less than 1 keV)was proposed to improve the ratio of C-N binding structures in the deposited films.

关键词： beam films amorphous

Variability of Multiphoton Detachment Rate Versus Laser Intensity

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Chinese Physics Letters 1996年第5期13卷 355-358页

作者： WANG Bing-bing ZHU Qi-ren PAN Shou-fu Institute of Atomic and Molecular Physics Jilin University.Changchun 130023

With the help of a model calculation based on the R-matrix-Floquet theory,the variability of multiphoton detachment rate versus laser intensity is in detail investigated.A number of interesting regularities,which can ... 详细信息

关键词： perturbation theory lowest