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Microstructure and performance of AZ80D magnesium alloy by purification of chloride flux containing Er

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Rare Metals 2014年第5期33卷 541-546页

作者： Zhong-Jun Wang guan-Qiao Su Wei-Ping Jia Qing-xiang Yang School of Material and Metallurgy University of Science and Technology Liaoning Key Laboratory of Materials Forming and Microstructure and Properties Control Education Department in Liaoning Province State Key Laboratory of Metastable Materials Science and Technology College of Materials Science and EngineeringYanshan University

The purification effects of Er addition in chloride flux during smelting on microstructure, tensile properties, and corrosion resistance of as-cast AZ80 D magnesium alloy were carried out. The results show that Er addition in the flux can eliminate the MgO inclusions and improve the tensile properties and corrosion resistance of the alloy. Using chloride flux mixed with 8.0 wt% Er, σb and δ of the as-cast AZ80 D magnesium alloy can be improved from 150 MPa and 2.1 % to the maximum value of 230 MPa and 4.8 %, respectively. Meanwhile, the corrosion rate decreases from 1.10 to 0.12 mg·（cm^2·d）^-1 in 5 wt% NaCl solution. However, with increasing Er content in chloride flux further, φ-（Al7ErMn5） and τ-（Al66.7Mg23.3Er10） phase are formed, and the morphology of γ-（Mg17Al12） phase is modified. The coarse φ-（Al7ErMn5）phase along dendrite boundaries decreases cohesion force between dendrites, which results in the worse of tensile properties.

关键词： Er Chloride flux AZ80D Microstructure Magnesium alloy

Semantic segmentation for remote sensing images based on an AD-HRNet model

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International Journal of Digital Earth 2022年第1期15卷 2376-2399页

作者： Xue Yang xiang Fan Mingjun Peng Qingfeng guan Luliang Tang School of Geography and Information Engineering China University of GeosciencesWuhanPeople’s Republic of China Wuhan Geomatics Institute WuhanPeople’s Republic of China State Key Laboratory of Information Engineering in Surveying Mappingand Remote SensingWuhan UniversityWuhanPeople’s Republic of China

Semantic segmentation for remote sensing images faces challenges of unbalanced category weight,rich context causing difficulties of recognition,blurred boundaries of multi-scale objects,and so *** address these problems,we propose a new model by combining HRNet with attention mechanisms and dilated convolution,denoted as:AD-HRNet for the semantic segmentation of remote sensing *** the framework of AD-HRNet,we obtained the weight value of each category based on an improved weighted cross-entropy function by introducing the median frequency balance method to solve the issue of class weight *** Shuffle-CBAM module with channel attention and spatial attention in AD-HRNet framework was applied to extract more global context information of images through slightly increasing the amount of *** address the problem of blurred boundaries caused by multi-scale object segmentation and edge segmentation,we developed an MDC-DUC module in AD-HRNet framework to capture the context information of multi-scale objects and the edge information of many irregular *** Postdam,Vaihingen,and SAMA-VTOL datasets as materials,we verified the performance of AD-HRNet by comparing with eight typical semantic segmentation *** results shown that AD-HRNet increases the mIoUs to 75.59%and 71.58%based on the Postdam and Vaihingen datasets,respectively.

关键词： Semantic segmentation convolutional neural networks dilated convolution attention mechanism remote sensing

Biomolecule-templated photochemical synthesis of silver nanoparticles： Multiple readouts of localized surface plasmon resonance for pattern recognition

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Nano Research 2018年第6期11卷 3213-3221页

作者： Fang Pu xiang Ran Meng guan Yanyan Huang Jinsong Ren Xiaogang Qu Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Cancer Center FirstAffiliated Hospital Jilin University Changchun 130061 China University of Chinese Academy of Sciences Beijing 100039 China

Silver nanoparticles （AgNPs） with distinct localized surface plasmon resonance （LSPR） absorption spectra can be synthesized using different proteins as templates upon irradiation by light. We utilized the multiple readouts of LSPR signals of AgNPs to construct sensor arrays for pattern recognition of proteins. Room temperature, aqueous solutions, and lack of harsh reducing reagents make the whole process inherently ＂green＂. Meanwhile, the strategy efficiently simplified the process of array-receptor preparation and data acquisition, leading to lower time consumption, sample use, and cost. Furthermore, the system can differentiate proteins using flexible and alterable sensor elements by choosing different combinations of LSPR signals at different wavelengths. The principle of the sensor design can also be further extended to differentiate other biomolecules. The study provides a new method to construct feasible, economical, and general nanoparficle-based sensing arrays for pattern recognition.

关键词： localized surface plasmon resonance silver nanoparticles pattern recognition biomolecule photochemical synthesis

Effect of stress ratio on very high cycle fatigue properties of Ti-10V-2Fe-3Al alloy with duplex microstructure

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Journal of Materials Science & Technology 2018年第7期34卷 1189-1195页

作者： Ying Wu Jianrong Liu Hao Wang Shaoxuan guan Rui Yang Hongfu xiang Institute of Metal Research Chinese Academy of Sciences National Demonstration Center for Experimental Materials Science and Engineering Education Jiangsu University of Science and Technology

In fatigue critical applications, Ti-10V-2Fe-3Al alloy components are expected to endure cyclic loading with cycles above 109. To assess their operating safety, S-N relations of Ti-10V-2Fe-3Al alloy in very high cycle fatigue （VHCF） regime are of concern and have been investigated in this work. Fatigue behavior including S-N curves and crack initiation mechanisms is reported. Two transitions of fatigue crack initi- ation mechanism, from internal crack initiation to surface crack initiation and from αp cleavage to αS/β decohesion, occur when the stress ratio （R） and stress level are reduced. Fatigue limits exist at Nr = 6×10^7 cycles for all stress ratios except for 0.5. In the VHCF regime two kinds of internal crack initiation mechanisms exist, i.e., coalescence of cluster of αp facets and αS/β decohesion. Their mutual competition depends on the stress ratio and can be interpreted in terms of different stress character required for promotion on different internal crack initiation mechanism. Small crack propagation is discussed to be life controlling process under the stress ratio range from -0.5 to 0.1 during VHCF regime while under the stress ratio 0.5 VHCF, life almost refers to the life required for crack initiation.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

关键词： Ti-10V-2Fe-3Al alloy Very high cycle fatigue S-N curve Fatigue crack initiation Life controlling process

Transverse Bending Characteristics in U-channel Forming of Tailor Rolled Blank

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Journal of Iron and Steel Research International 2016年第12期23卷 1249-1254页

作者： Hua-wei ZHANG Ying-ping guan Jia-lu WU xiang-hua LIU School of Control Engineering Northeastern University at Qinhuangdao College of Mechanical Engineering Yanshan University Research Institute of Science and Technology Northeastern University

Research on the formability of tailor rolled blank （TRB） is of good practical significance and application value because of the enormous potential of TRB in the aspect of automobile lightweight. However, the forming of TRB is problematic because of the varying properties; especially, springback is a main challenge. The transverse bending （bending axis is perpendicular to the rolling direction） of TRB U channel was studied through simulation and experiment. The forming characteristics of TRB U channel during transverse bending were analyzed. The mechanisms of forming defects, including bending springback and thickness transition zone （TTZ） movement, were revealed. On this basis, effects of blank geometric parameters on springbaek and TTZ movement were discussed. The results indicate that springback and TTZ movement happen during transverse bending of TRB U-channel. Nonuni form stress distribution is the most fundamental reason for the occurrence of springback of TRB during transverse bending. Annealing can eliminate nonuniform stress distribution, and thus diminish springbaek of TRB, especially springback on the thinner side. Therefore, springback of the whole TRB becomes more uniform. However, annealing can increase the TTZ movement. Blank thickness and TTZ position are the main factors affecting the formability of TRB U-channel during transverse bending.

关键词： tailor rolled blank transverse bending springback U-channel annealing thickness transition zone

Neuroprotective effect of chitosan nanoparticle gene delivery system grafted with acteoside (ACT) in Parkinson's disease models

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Journal of Materials Science & Technology 2020年第8期36卷 197-207页

作者： Yongyong Xue Na Wang Zhi Zeng Jinpeng Huang Zhiming xiang Yan-Qing guan MOE Key Laboratory of Laser Life Science&Institute of Laser Life Science College of BiophotonicsSouth China Normal UniversityGuangzhou510631China School of Life Science South China Normal UniversityGuangzhou510631China South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research Panyu Central HospitalGuangzhouChina Department of Radiology Guangzhou Panyu Center HospitalGuangzhou511400China

Developing new drugs to treat Parkinson's disease efficiently is challenging. Here we report that chitosan nanoparticles(APPDNs) could serve as novel candidates for the design of anti-PD drugs. In this study, we investigated the effects of chitosan poly ethyleneglycol-poly lactic acid(PEG-PLA) nanoparticles conjugated with nerve growth factor(NGF), acteoside(ACT) and plasmid DNA(p DNA) for PD therapy using in vitro and in vivo models. Using PD cell models, we demonstrated that APPDN had good neuroprotective effects. More significantly, experiments using mouse PD models demonstrated that APPDNs could ameliorate the behavioral disorders of sick mice. Immunohistochemical and western blot(WB) analyses demonstrated that APPDNs could significantly reverse dopaminergic(DA) neuron loss in the substantia nigra and striatum of sick mice. This study opens up a novel avenue to develop anti-PD drugs.

关键词： Parkinson's disease Chitosan nanoparticles Acteoside Gene therapy pDNA

Tissue factor with age-related macular degeneration

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International Journal of Ophthalmology(English edition) 2012年第5期5卷 609-613页

作者： guan-feng Wang Xiu-Lan Zou Department of Ophthalmology Guangzhou General Hospital of Guangzhou Military Command Guangzhou 510010 Guangdong Province China Jinan University Guangzhou 510630 Guangdong Province China

Wet age-related macular degeneration which incidence increases year by year is a blinding eye disease, but current clinical methods of treatment on this disease are limited and the outcome is not ideal. Recent studies have found abnormally high expression of tissue factors which are targets for the treatment of wet age-related macular degeneration to achieve a certain effect in the choroidal neovascularization. Related literatures are reviewed as following.

关键词： wet age-related macular degeneration choroidal neovascularzation tissue factor photodynamic therapy immunotherapy

Application of silicocalcium in Mg-6Al-0.5Mn alloy

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China Foundry 2007年第4期4卷 284-287页

作者： WANG Li-guo ZHANG Bao-feng ZHU Shi-jie ZHANG Chun-xiang guan Shao-kang School of Materials Science and Engineering Zhengzhou University Zhengzhou 450002 China Huanghe Science and Technology College Zhengzhou 450062 China

The mechanical properties of magnesium alloys at both ambient and elevated temperatures can be improved with the existence of Mg2Si phase in the ***,these properties can be deteriorated if the Mg2Si phase is of coarse Chinese script *** of the silicocalcium addition on the microstructure and properties of an Mg-6Al-0.5Mn alloy(AM60)were *** microstructure of the alloy with the addition of silicocalcium is featured with dispersedly distributed small polygonal type Mg2Si *** microhardness,tensile strength,percentage elongation and toughness of as-cast AM60+1.0Si-Ca alloy are 20%,13.3%,28.5% and 50% higher than these of AM60 alloy *** corrosion measurements showed that the silicocalcium-modified AM60 alloy increases the corrosion potential by 0.04V and decreases the lost weight corrosion rate by 45%.

关键词： silicocalcium magnesium alloy microstructure mechanical properties corrosion

Identification and quantification of benzimidazole metabolites of thiophonate-methyl sprayed on celery cabbage using SiO_2@NiO solid-phase extraction in combination with HPLC-MS/MS

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Chinese Chemical Letters 2020年第2期31卷 482-486页

作者： Qiongwei Yu Shijie Liu feng Zheng Huaming Xiao Hongyan guan Yuqi feng Key Laboratory of Analytical Chemistry for Biologyand Medicine(Ministry of Education) Department of ChemistryWuhan UniversityWuhan 430072China Quality Management Department Wuhan Hiteck Biological Pharma Co.Ltd.Wuhan 430056China

Thiophonate-methyl(TPM) is one of fungicides and pesticides widely used in agriculture ***,the residue of its benzimidazole(BZD) metabolites in related agricultural products poses a potential risk to *** this paper,nickel oxide nanoparticle-deposited silica(SiO_2@NiO) composite was used for the selective enrichment and purification of TPM's BZD metabolites in celery cabbage sprayed with ***,high-performance liquid chromatography coupled with precursor ion scan-mass spectrometry(HPLC-PIS-MS) and high-resolution MS/MS analysis(HR-MS/MS) was utilized for their qualitative and quantitative ***-one potential TPM's BZD metabolites were found and four of them were *** metabolite was discovered for the first ***,a robust and sensitive quantitative method was developed with good linearities(R^2> 0.9972) within a wide range of 10.00-1000 ng/*** detection limits of three known TPM's metabolites were within the range of 3.20-4.90 ng/*** standard deviations(RSDs) of intra-day and inter-day precisions were less than 18.3%,which showed perfect *** method was successfully applied to monitoring TPM's BZD metabolites in celery cabbage sprayed with TPM and the concentration versus time curves of TPM's metabolites in celery cabbage were *** method is expected to be used to monitor BZD residues in various fruits and vegetables.

关键词： Thiophonate-methyl Benzimidazole metabolites Precursor ion scan-mass spectrometry High-resolution MS/MS analysis Celery cabbage