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Tempering mechanism of lath martensite induced in IF steel under high pressure

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Journal of Materials Science & Technology 2023年第29期160卷 148-160页

作者： Zuohua Wang Haidong Sun Xiaogang Guo Peng Wang Ning Liu Dongli Yu hongwang Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Liren College of Yanshan University Yanshan UniversityQinhuangdao 066004China

In this paper,low-and high-strength lath martensite(350 and 640 HV)was fabricated in an IF steel via high pressure martensitic *** microstructure and the softening during their tempering from 200°C to 800°C for 1 h were systematically investigated.A carbon-irrelevant tempering process was proposed,exhibiting a three-stage structural evolution pattern depending upon the tempering de-gree(1-(HV-HV FP)/(HV NP-HV FP),where the HV is the instant hardness,HV NP is the non-tempered hard-ness and HV FP is the fully tempered hardness):(1)low tempered(50%),clearing up the remained variant laths via the migration of the triple ***-type microstructure is tailored by low-index lamellar variant boundaries and is thus intrinsically thermally stable,whereas the mobile terminal tips decrease the tempering *** underlying mechanism for such carbon-irrelevant process was discussed and the potential effect on the tempering behavior of carbon-contained martensite was highlighted.

关键词： Tempering mechanism Lath martensite IF steel Terminal tip migration High pressure

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改进暗通道原理下视觉图像光晕消除算法

现代电子技术 2025年第1期48卷 60-64页

作者：任晓楠李广中北大学山西太原030051

在光晕区域附近进行光晕消除操作可能会降低图像的对比度、清晰度和细节。因此,需要开发有效的方法来恢复和增强光晕消除后的图像细节,以确保整体图像质量的提高,为此设计一种改进暗通道原理下视觉图像光晕消除算法。建立大气散射模型... 详细信息

在光晕区域附近进行光晕消除操作可能会降低图像的对比度、清晰度和细节。因此,需要开发有效的方法来恢复和增强光晕消除后的图像细节,以确保整体图像质量的提高,为此设计一种改进暗通道原理下视觉图像光晕消除算法。建立大气散射模型深度分析光晕产生条件,根据图像中的像素强度值计算成像环境中的透射率,按照大气光照的散射系数建立光照条件研究模型。在较高的像素颜色通道条件下,根据图像中高亮度和强反射部分搭建无光晕图像亮通道定义,聚类图像亮通道特征,利用快速双边滤波器细化透射率,建立光晕图像的成像模型。在改进暗通道原理的过程中通过调整多个计算参数,包括改变权重函数,设置光晕消除的恢复指令,完成对视觉图像的光晕消除处理。经过实验分析可以证明,所提方法具备良好的光晕消除性能,光晕消除效果较好。

关键词：改进暗通道视觉图像光晕消除透射率多尺度算法大气散射模型

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Twinned substructure in lath martensite of water quenched Fe-0.2%C and Fe-0.8%C steels

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Journal of Materials Science & Technology 2020年第14期47卷 126-132页

作者： Haidong Sun Yuhui Wang Zuohua Wang Ning Liu Yan Peng Xiujuan Zhao Ruiming Ren hongwang Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao066004China Liren College of Yanshan University Yanshan UniversityQinhuangdao066004China School of Materials Science&Engineering Dalian Jiaotong UniversityDalian116028China

In the present investigation,twinned substructures within lath martensite of two water quenched steels(0.2 wt.%C and 0.8 wt.%C)were *** lath martensite has typical hierarchical packet-block-lath with dislocation ***,laths that are misoriented by/70.5°or/60° and bordered by{011}plane,namely twinned laths,are observed,of which the density increases and the scale decreases as more carbons were *** twinned laths have body centered cubic(bcc)crystal structure,belonging to twinned variants following the classical Kurdjumov-Sachs(K-S)orientation relationship with respect to the parent *** bcc{112}twins,twinned variants produce strong double diffraction and in turn the extra diffraction spots that are commonly observed in the martensite in steels with wide range of carbon contents.

关键词： Twinned variant Lath martensite Double electron diffraction Orientation relationship Steels

Low temperature impact toughness and fracture mechanism of cast QT400-18L ductile iron with diferent Ni additions

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China Foundry 2013年第5期10卷 310-314页

作者： Zhang Xinning Qu Yingdong Yang hongwang Li Rongde School of Materials Science and Engineering Shenyang University of Technology

Different contents of Ni(0.3wt.%to 1.2wt.%)were added to the QT400-18L ductile iron to investigate the effect of Ni addition on the impact toughness of cast ductile irons at low *** impact toughnesses of the samples at room and low temperatures were *** microstructures and fractographs were *** show that with the increase of Ni addition there is a general trend of refinement of the ferrite matrix while the nodule density shows no obvious *** the Ni content is 0.7wt.%,the matrix structure is the refined ferrite with a very small fraction(about 2%)of pearlite near the eutectic cell *** the Ni content is further increased,the fraction of pearlite increases significantly and reaches more than 5%when 1.2wt.%Ni is *** impact toughness at room temperature increases as the content of Ni increases from 0.3 wt.%to 0.7 wt.%,but decreases as the Ni content further increases to 1.2wt.%due to the increase of pearlite *** maximum value of the impact work is 18.5 J at room temperature with 0.7wt.%Ni *** average value of the impact work is still more than 13 J even at-30℃.In addition,the fracture mechanism changes from ductile manner to brittleness as the testing temperature decreases from 20℃to-60℃.

关键词： Ni ductile iron low temperature impact toughness fracture morphology

Twinned Martensitic Substructure in a Water Quenched Fe–1.0 wt%C Alloy

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Acta Metallurgica Sinica(English Letters) 2022年第7期35卷 1157-1163页

作者： Haidong Sun Zuohua Wang Shuai Zhang Ning Liu Pinwen Zhu Dongli Yu hongwang Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China Liren College of Yanshan University Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A Fe–1.0 wt%C alloy was quenched into water from 1100 ℃,leading to lath martensite and plate martensite of body-centered tetragonal *** these two martensites have the twinned substructure that generates mirror symmetric diff raction patterns with extra diff raction spots around n/3(112).The twinned substructure has the origin from twinned martensitic variants,namely twin-related crystals separated by{110},rather than{112}deformation *** eff ect on the electron double diff raction of twinned variants was discussed.

关键词： Twinned martensitic substructure Twinned variant Lath martensite Plate martensite

Strain gradient induced grain refinement far below the size limit in a low carbon hypoeutectoid steel(0.19 wt%C)via pipe inner surface grinding treatment

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Journal of Materials Science & Technology 2021年第19期78卷 155-169页

作者： Wenqiang Li Yiming Zhao Ning Liu Changji Li Ruiming Ren Dayong Cai hongwang Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China National Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Liren College of Yanshan University Yanshan UniversityQinhuangdao 066004China School of Materials Science&Engineering Dalian Jiaotong UniversityDalian 116028China Qinhuangdao Vocational and Technical College Qinhuangdao 066100China

A low carbon hypoeutectoid steel(0.19 wt%C)with proeutectoid ferrite and pearlite dual-components was subjected to surface plastic deformation via pipe inner surface grinding(PISG)at room *** deformation microstructures for each component were systematically characterized along depth,and the patterns of structural evolution toward nanometer regime as well as the governing parameters were *** ferrite grains were refined down to 17 nm,and the pattern covering a length scale of 4–5 orders of magnitude from micron-to nanometer-scale follows:formation of cellular dislocation structure(CDS),elongated dislocation structure(EDS),ultrafine lamellar structure(UFL)and finally the nanolaminated structure(NL).The pearlite experiences the deformation and refinement,and finally the transforming the ultrafine pearlite(UFP)into nanolaminated pearlite(NLP)with the ferrite lamellae as thin as 20 *** for both UFL(UFP)and NL(NLP)can be realized via forming novel extended boundaries within ferrite lamellae.A critical lattice curvature of~2.8°is required for forming such extended boundary,corresponding to a minimum strain gradient of 0.25μm^(-1)for a 100 nm-thick *** below size limit(expressed by lamellar thickness d_Tin nm)is correlated with the strain gradient(χ,inμm^(-1))by:d_T=12.5/*** contributions from strain gradient caused by PISG processing and material heterogeneity were discussed.

关键词： Strain gradient Grain refinement Size limit Low carbon hypoeutectoid steel Pipe inner surface grinding

Synthesis of melamine-formaldehyde microcapsules containing oil-based fragrances via intermediate polyacrylate bridging layers

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2574-2580页

作者： Yanping He Shunzhi Yao JunzhengHao hongwang Linhua Zhu TianSi Yanlin Sun Jianhao Lin School of Chemical Engineering Kunming University of Science and TechnologyChenggong CampusKunming 650504China Faculty of Science Kunming University of Science and TechnologyChenggong CampusKunming 650504China

A general and versatile strategy to prepare melamine-formaldehyde(MF)microcapsules encapsulating oil-based fragrances by combining solvent evaporation and in situ polymerization was proposed in this *** oil-based fragrance was pre-encapsulated by an inner polyacrylate membrane via solvent evaporation,followed by in situ polymerization of MF precondensates as an outer *** polyacrylate membrane is used as an intermediate bridging layer to stabilize the oil-based fragrance,and to provide driving forces for in situ polymerization of MF precondensates through electrostatic attractions between carboxyl groups and ammonium *** was demonstrated that MF microcapsules containing clove oil were prepared *** amount and the composition of the intermediate polyacrylate bridging layer were *** and sphere-shaped MF-clove oil microcapsules were prepared when the weight ratio of polyacrylate to clove oil was over 60 wt%and the concentration of acrylic acid(AA)increased to 10 wt%in *** addition,MF microcapsules containing sunflower oil and hexyl salicylate were prepared by using this *** work suggests that this new approach can be potentially used to encapsulate various core materials,tuning the shell properties of microcapsules such as thickness,mechanical strength and release properties.

关键词： Melamine formaldehyde Microcapsule Oil-based fragrance Particle Polymers Synthesis

Role of Ni species in ZnO supported on Silicalite-1 for efficient propane dehydrogenation

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Chinese Journal of Chemical Engineering 2022年第3期35卷 240-247页

作者： Bofeng Zhang Mingxia Song hongwang Liu Guozhu Li Sibao Liu Li Wang Xiangwen Zhang Guozhu Liu Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Zhejiang Institute of Tianjin University Ningbo 315201China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Propane dehydrogenation(PDH)is one of the most effective technologies to produce ***-noble zinc-based catalysts have paid increasing attention because of low cost and nontoxic,compared with industrial Pt and Cr-based ***,they often suffer from limited catalytic activity and poor ***,we introduced moderate Ni into ZnO supported Silicalite-1 zeolite to increase catalytic activity and stability ***^(2+) was the definite active site and NiZn alloy facilitated the sluggish H recombination into H_(2)via reverse ***,the introduction of Ni increased Lewis acid strength caused by electron transfer from ZnO to NiZn alloy,contributing to improved *** resulted 0.5 NiZn/S-1,propene formation rate was 0.18 mol C_(3)H_(6)·(g Zn)^(-1)·h^(-1) at 550℃,which was above 1.5 times higher than that over Zn/S-1 without *** stability test,the deactivation of0.5 NiZn/S-1 was 0.019 h^(-1),which was only 1/10 of that over Zn/S-1.

关键词： Propane dehydrogenation NiZn alloy Reverse hydrogen spillover Lewis acid Zeolite

Photoregulated or Energy Dependent Process of Hormogonia Differentiation in Nostoc sphaeroides Kutzing （Cyanobacterium）

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Journal of Integrative Plant Biology 2005年第6期47卷 709-716页

作者： Dun-HalLI Lan-ZhouCHEN Gen-BaoLI Gao-hongwang Li-RongSONG Yong-DingLIU StateKeyLaboratoryofFreshwaterEcologyandBiotechnology InstituteofHydrobiologytheChineseAcademyofSciencesWuhan430072China SchoolofResourceandEnvironmentSciences WuhanUniversityWuhan430072China

Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation ofNostoc sphaeroides Kiitzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5-10μmol·m^-2·s^-1 photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different fight radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy deoendent orocess.

关键词： cyanobacterium energy-dependent hormogonia differentiation Nostoc sphaeroides Kützing photoregulation.