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Improving fatigue properties of normal direction ultrasonic vibration assisted face grinding Inconel 718 by regulating machined surface integrity

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International Journal of Extreme Manufacturing 2024年第3期6卷 458-475页

作者： Nianwei Xu Renke Kang Bi Zhang Yuan Zhang Chenxu Wang yan bao Zhigang Dong State Key Laboratory of High-Performance Precision Manufacturing Dalian University of TechnologyDalian 116024People’s Republic of China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055People’s Republic of China

Fatigue properties are crucial for critical aero-engine components in extreme serviceenvironments,which are significantly affected by surface integrity(SI)indexes(especially surface topography,residual stressσ_(res),and microhardness)after machining ***-direction ultrasonic vibration-assisted face grinding(ND-UVAFG)has advantages in improving the machinability of Inconel 718,but there is a competitive relationship between higher compressiveσ_(res)and higher surface roughness R_(a)in affecting fatigue *** lack of a quantitative relationship between multiple SI indexes and fatigue strength makes theindeterminacy of a regulatory strategy for improving fatigue *** this work,a model of fatigue strength(σ_f)_(sur)considering multiple SI indexes was ***,high-cycle fatigue tests were carried out on Inconel 718 samples with different SI characteristics,and the influence of ND-UVAFG process parameters on SI was *** on SI indexes data,the(σ_f)_(sur)distribution in the grinding surface layer for ND-UVAFG Inconel 718 samples was determined using the developed model,and then the fatigue crack initiation(FCI)sites were *** predicted FCI sites corresponded well with the experimental results,therebyverifying this model.A strategy for improving the fatigue life was proposed in this work,which was to transfer the fatigue source from the machined surface to the bulk material by controlling the SI ***,a critical condition of SI indexes that FCI sites appeared on the surface or in bulk material was given by fitting the predicted *** to the critical condition,an SI field where FCI sites appeared in the bulk material could be *** this field,thefatigue life of Inconel 718 samples could be improved by approximately 140%.

关键词： surface integrity fatigue strength Inconel 718 ultrasonic assisted grinding

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Inclusion Variations of Hot Working Die Steel H13 in Refining Process

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Journal of Iron and Steel Research International 2012年第11期19卷 1-7页

作者： LIU Jian-hua WANG Guo-xuan bao yan-ping yanG yan YAO Wei CUI Xiao-ning Metallurgical Engineering Institute University of Science and Technology BeijingBeijing 100083China Technical Center Zhongyuan Special Steel Co LtdJiyuan 454685HenanChina

Inclusion variations of die steel H13, including changes of species, morphologies, compositions, amounts and sizes, in the production of EAF-LF--VD-ingot casting-electro slag refining （ESR） procedure, were investi- gated by systematic sampling, and analyzed with scanning electron microscope （SEM）, energy dispersive spectrum （EDS） , and metallographic microscope. The variation mechanism was studied by comprehensive analysis of total oxygen, nitrogen, and acid soluble aluminum as well as chemical test of refining slag. Based on the investigations, technical measures for cleanness improvement were discussed. The resuhs show that oxide inclusions in H13 steel change from irregular Al2O3- near globular CaO-MgO-Al2O3 and CaO-Al2O3-SiO2 complex inclusions-finer CaO- Al2O3-SiO2 inclusions with higher CaO content-CaO-Al2O3-SiO2 inclusions with higher Al2O3 content and irregular MgO-AI203 inclusions--fine irregular MgO-Al2O3-CaS inclusions in various steps of the production; the variations are related with changes of acid soluble aluminum content, reactions between slag and steel, re-oxidation of liquid steel during casting, and refining of ESR. It is also found that Al2O3 inclusions are modified by refining slag in LF and VD refining~ and ESR plays a good role in inclusion removal, especially in controlling the large linear VC-CrC- MoC inclusions distributed in grain boundaries. It is suggested that casting protection should be improved, and the basicity of refining slag and acid soluble aluminum content in steel should be raised.

关键词： hot working die steel ESR cleanness refining slag modification

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Fabrication of super-elastic graphene aerogels by ambient pressure drying and application to adsorption of oils

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Chinese Journal of Chemical Engineering 2022年第7期35卷 89-97页

作者： Xinxin Zhao Wenlong Xu Shuang Chen Huie Liu Xiaofei yan yan bao Zexin Liu Fan yang Huan Zhang Ping Yu State Key Laboratory of Heavy Oil Processing China University of Petroleum(Huadong)Qingdao 266580China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China

Three-dimensional graphene-based aerogels have promising applications in oil adsorption and environmental ***,current research of graphene-based aerogels is often hindered by high preparation cost,poor mechanical properties and low recycling ***,superelastic graphene aerogel(SGA)was prepared through one-step freezing and twice hydrothermal reduction followed by drying under ambient *** simple atmospheric drying provides a possibility for large-scale preparation of high performance graphene-based *** prepared SGA not only has the ability of highly repeatable compression rebound,but also exhibits excellent oil adsorption *** the overall performance of SGA is better than most of graphenebased aerogels prepared by freeze *** the SGA was cyclically compressed with 70%strain for 300 times,it can return to the original shape and height *** retained about 90%of the initial adsorption capacity after 50 cycles of adsorption and compression regeneration for cyclohexane.

关键词： Graphene aerogels Super-elastic Ambient pressure drying Adsorption and regeneration of oil

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Denaturation behavior of inclusions in industrial pure iron by calcium treatment

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Journal of Iron and Steel Research International 2023年第2期30卷 249-258页

作者： Xin Liu yan-ping bao Cheng-jian Hua Jian-hua Chu Chao Gu Min Wang State Key Lab of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China

Only a few Chinese enterprises can produce high-quality industrial pure iron,and studies on the smelting process of industrial pure iron were *** inclusions in a melting process were characterized by means of electron microscopy and an automatic inclusion analysis system,and the evolution mechanism of inclusion was studied using thermodynamic calculation to optimize the calcium alloy addition in liquid *** results show that during the smelting process,inclusions mainly composed of Al_(2)O_(3)and spinel are formed before calcium *** calcium treatment,they continuously react with[Ca],[S]and[Ti],grow up,and are removed during refining and tundish *** the end,there are more small-sized inclusions containing CaS,and the contents of Al_(2)O_(3)and spinel are *** to thermodynamic calculations,the appropriate calcium treatment liquid window for the molten steel composition is(10-38)×10^(-6).Calcium treatment has changed the main types of inclusions in industrial pure iron from Al_(2)O_(3)to small-sized inclusions containing CaS and effectively reduces the influence of Al_(2)O_(3)inclusions on the quality of industrial pure iron.

关键词： Industrial pure iron Calcium treatment Inclusion Thermodynamic CaS

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Effect of Ce on the cleanliness, microstructure and mechanical properties of high strength low alloy steel Q690E in industrial production process

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International Journal of Minerals,Metallurgy and Materials 2019年第11期26卷 1372-1384页

作者： Hao Wang yan-ping bao Ming Zhao Min Wang Xiao-ming Yuan Shuai Gao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Technical Center of Inner Mongolia baotou Steel Union Co. Ltd.Baotou 014010China The Rare Earth Steel Plates Plant of baotou Iron and Steel Co. Ltd.Baotou 014010China

In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic *** results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation *** inclusions were *** size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was *** played a role in purifying molten steel through desulphurization and ***,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar *** average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled *** addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was *** rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening *** properties such as tensile,yield,and low-temperature impact toughness were significantly improved.

关键词： rare earth HSLA steel inclusion structure grain refinement strengthening

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Genome-wide microarray-based analysis of miRNAs expression in patients with acute-onchronic liver failure

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Hepatobiliary & Pancreatic Diseases International 2014年第1期13卷 32-39页

作者： Wen Chen Ze-Hui yan Yu-Ming Wang bao-yan Xu Guo-Hong Deng Institute of Infectious Diseases Southwest Hospital Third Military Medical University Chongqing Key Laboratory for Research of Infectious Diseases

BACKGROUND: Acute-on-chronic liver failure(ACLF) is a severe clinical syndrome that may cause a high mortality. However, the mechanism is still not clear. Characterization of the microRNA(miRNA) profiles in ACLF patients may provide new clues to the pathogenesis and management of this syndrome. METHODS: Genome-wide microarray was performed to compare the different miRNA expression profiles in peripheral blood mononuclear cells of a pair of monozygotic twins, an ACLF patient and an HBV asymptomatic carrier(AsC). The case-control miRNA profiles were compared and confirmed by quantitative reverse transcription-polymerase chain reaction in 104 ACLF patients and 96 AsCs. A combined computational prediction algorithm was used to predict the potential target genes. RESULTS: Forty-five miRNAs were increased and eight miRNAs were decreased in the ACLF group. The expressions of hsa-let-7a and hsa-miR-16 were increased by 8.58- and 8.63-fold in ACLF patients compared with that in AsCs, respectively(P<0.001). CARD8, BCL2, IL1RAPL1, LTB, FZD10 and EDA were identified as the target genes of hsa-miR-16; MAP4K3, OPRM1, IGF2BP1 and CERCAM were verified as the target genes of hsa-let-7a. CONCLUSIONS: Our results showed that there is a close relationship between specific miRNAs of peripheral blood mononuclear cells and ACLF. hsa-miR-16 and hsa-let-7a may contribute to the development of ACLF.

关键词： acute-on-chronic liver failure microRNA microarray twins

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Modeling study on the flow patterns of gas–liquid flow for fast decarburization during the RH process

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International Journal of Minerals,Metallurgy and Materials 2018年第2期25卷 153-163页

作者： Yi-hong Li yan-ping bao Rui Wang Li-feng Ma Jian-sheng Liu Collaborative Innovation Centre of Taiyuan Heavy Machinery Equipment and School of Materials Science and Engineering Taiyuan University of Science and Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Materials Science and Engineering North University of China

A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.

关键词： modeling study flow pattern vacuum chamber residence time decarburization RH process

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Separation and Recovery of Phosphorus from P-bearing Steelmaking Slag

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Journal of Iron and Steel Research International 2014年第5期21卷 496-502页

作者： Lu LIN yan-ping bao Min WANG Wei JIANG Han-mei ZHOU State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing National Engineering Research Center of Flat Rolling Equipment University of Science and Technology Beijing Journals Publishing Center University of Science and Technology Beijing

In order to recycle the phosphorus from P-bearing steelmaking slag, the influences of magnetic field inten- sities, slag particle sizes and slag compositions were investigated by magnetic separation experiments. SiO2, A1203 and TiO2 melting modification of converter slag was made respectively and phosphorus-rich phase was extracted by magnetic separation. The results show that MgO, MnO, Na2 0 and CaF2 have little effect on the phosphorus recovery, whereas the addition of SiO2, Al2 03, and TiO2 has great effect on phosphorus enrichment in slag and magnetic separation. With adding the reagent of SiO2 Al2 03 and TiO2, recycled non-magnetic substances are increased obviously and P2 05 content in nowmagnetic substances and phosphorus recovery rate are also increased. The phosphorus recovery rates of modified slag No. 8 （SiO2 modification）, slag No. 10 （AI2 03 modification） and slag No. 11 （TiO2 modification） are 84.75 %, 82.16 % and 74.46 %, respectively. Then, most of phosphorus was recycled.

关键词： phosphorus magnetic separation melting modification phosphorus recovery rate P-bearing steelmak-ing slag

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A novel way to synthesize Pb nanotapes in liquid ammonia

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Chinese Chemical Letters 2011年第8期22卷 993-996页

作者： Lei Sun Meng Lei Zhang Xiao Jun Tao yan bao Zhao Key Laboratory for Special Functional Materials of Ministry of Education Henan University Kaifeng 475004 China

Lead nanotapes were synthesized in liquid ammonia solvent in the presence of sodium metal at low *** process was template *** electron microscopy（TEM） observations and X-ray diffraction（XRD） characterizations revealed that the as-prepared Pb nanotapes have average diameters in the range of 40-50 *** lengths up to several hundred nanometers, and exhibit cubic crystal structures.

关键词： Pb Nanotapes Chemical synthesis Liquid ammonia

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Changes of DOM and its correlation with internal nutrient release during cyanobacterial growth and decline in Lake Chaohu, China

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Journal of Environmental Sciences 2023年第2期124卷 769-781页

作者： yan bao Tao Huang Chengwu Ning Tingting Sun Pengliang Tao Jie Wang Qingye Sun School of Resources and Environmental Engineering Anhui UniversityHefei 230601China Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration Anhui UniversityHefei 230601China

The seasonal changes in dissolved organic matter(DOM),and its correlation with the release of internal nutrients during the annual cycle of cyanobacteria in the eutrophic Lake Chaohu,China,were investigated from four sampling periods between November 2020 and July *** DOM fluorescence components were identified as protein-like C1,microbial humic-like C2,and terrestrial humic-like *** highest total fluorescence intensity(FT)of DOM in sediments during the incubation stage is due to the decomposition and degradation of cyanobacteria *** lowest humification of DOM and the highest proportion of C1 in waters during the initial cyanobacterial growth indicate that fresh algae are the main *** highest molecular weight of DOM and FT of the C2 in sediments during cyanobacterial outbreaks indicate the concurrent deposition of undegraded cyanobacterial remains and microbial *** components of DOM are affected mainly by the dissolved total phosphorus in waters,while the temperature drives the annual cycle of *** decreasing C1 in sediments and increasing nutrients in waters from the cyanobacterial incubation to outbreak indicate that mineralization of algal organic matter contributes importantly to the release of internal nutrients,with the strongest release of phosphorus observed during the early growth of *** humic-like C2 and C3 components could also affect the dynamics of internal phosphorus through the formation of organic colloids and organic–inorganic *** results show that the degradation of DOM leads to nutrients release and thus supports the continuous growth of cyanobacteria in eutrophic Lake Chaohu.

关键词： Eutrophication Shallow lake Sediment-water interface Algal blooms Fluorescence components PARAFAC

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