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A Hf-doped dual-phase high-entropy alloy: phase evolution and wear features

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Rare Metals 2024年第1期43卷 324-333页

作者： Hao Ren Rui-Run Chen xue-feng gao Tong Liu Gang Qin Yu-Lung Chiu Shi-Ping Wu Jing-Jie Guo National Key Laboratory for Precision Hot Processing of Metals School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China School of Metallurgy and Materials University of BirminghamEdgbastonBirmingham B152TTUK

Initially defined high entropy alloys(HEAs)usually exhibit a single-phase solid-solution ***,two and/or more types of phases in HE As possibly induce the desired microstructure features,which contribute to improving the wear properties of HE ***,we prepare a series of(AlCoCrFeNi)_(100-x)Hf_(x)(x=0,2,4and 6;at%) HEAs and concern their phase compositions,micro structures and wear *** leads to the formation of(Ni,Co)_(2)Hf-type Laves phase and tailors the microstructure from a body-centered cubic(BCC) singlephase structure to a hypoeutectic *** increased hardness from~HV 512.3 to~HV 734.1 is due to solid-solution strengthening,grain refinement strengthening and precipitated phase *** a few oxides(Al_(2)O_(3)+Cr_(2)O_(3)) caused by the wear heating contribute to an 85.5% decrease in wear rate of the HEA system from6.71×10^(-5) to 0.97×10^(-5) m^(3)·N^(-1)·m^(-1).In addition,Hf addition changes the wear mechanism from abrasive wear,mild oxidative wear and adhesive wear to oxidative wear and adhesive wear.

关键词： High entropy alloy Laves phase Hardness Wear mechanism

白莲河流域总磷关键源区识别与最佳管理措施(BMPs)研究

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长江流域资源与环境 2024年第2期33卷 374-386页

作者：桑灿李兆华冯学高张劲湖北大学资源环境学院湖北武汉430062 荆门市生态环境局沙洋分局湖北荆门448299

白莲河水库是鄂东地区重要的饮用水源地之一,然而随着流域经济的高速发展和城镇化水平的不断提高,使白莲河水库水质有所退化,严重影响流域内生产生活的用水安全。运用SWAT模型,采用2011~2021年时间序列的土地利用类型、土壤类型等基础数... 详细信息

白莲河水库是鄂东地区重要的饮用水源地之一,然而随着流域经济的高速发展和城镇化水平的不断提高,使白莲河水库水质有所退化,严重影响流域内生产生活的用水安全。运用SWAT模型,采用2011~2021年时间序列的土地利用类型、土壤类型等基础数据,模拟白莲河流域总磷负荷空间分布特征,并利用单位面积负荷指数法识别关键源区,模拟了最佳管理措施(BMPs)在白莲河流域总磷的削减效果。结果表明:(1)白莲河流域TP负荷强度下游区域高于上游,关键源区为位于方家咀乡、农业活动强度较大的三个子流域,三者占流域总面积的1.7%,TP总负荷量占流域总负荷的24.9%。(2)2018~2021年白莲河流域年均总磷负荷量为181.7 t,TP源产区呈现明显的空间差异,其中位于方家咀乡的子流域年均TP负荷量最大,负荷量为18.9 t/a。(3)单一BMPs中,总磷负荷削减效率最高的是田间面积比为5的植被缓冲带,削减率为50.5%,其次为2 km河道植草,削减率为50.2%;综合BMPs可有效降低TP负荷强度,特别是TP负荷的关键源区,关键源区的TP负荷削减率为60.9%。研究结果可为白莲河流域运用综合BMPs措施来控制流域的总磷负荷提供科学参考。

关键词：白莲河关键源区 SWAT模型总磷负荷最佳管理措施(BMPs)

异质结构CoCrFeNiW高熵合金的拉伸性能和强化行为

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Transactions of Nonferrous Metals Society of China 2024年第3期34卷 890-904页

作者：高雪峰陈峣任浩秦刚周启文陈瑞润郭景杰哈尔滨工业大学金属精密热加工国家重点实验室哈尔滨150001 沈阳工业大学材料科学与工程学院沈阳110870

采用真空电弧熔炼方法制备Co_(30)Cr_(30)(FeNi)_(40-x)W_(x)(x=0~8%(摩尔分数),分别简化为HWO~HW8)高熵合金。研究铸态和退火态合金的显微组织和拉伸性能。结果表明,HW2和HW4具有单一的FCC相。随着W含量和退火温度的增加,细小粒状μ相... 详细信息

采用真空电弧熔炼方法制备Co_(30)Cr_(30)(FeNi)_(40-x)W_(x)(x=0~8%(摩尔分数),分别简化为HWO~HW8)高熵合金。研究铸态和退火态合金的显微组织和拉伸性能。结果表明,HW2和HW4具有单一的FCC相。随着W含量和退火温度的增加,细小粒状μ相的面积分数增加且分散在FCC基体中。软FCC基体和硬μ相构成应变不相容的异质结构。随着W含量从0增加到8%(摩尔分数),屈服强度和抗拉强度分别从278和629 MPa提高到530和839 MPa,应变维持在33%。退火后的HW8表现出优异的屈服强度(810 MPa)和抗拉强度(1087 MPa)。屈服强度的提高归因于固溶、沉淀和背应力强化。异质结构中产生的背应力强化作用诱导高硬化行为,在提高抗拉强度和塑性方面发挥着主导作用。

关键词：高熵合金异质结构拉伸性能应变硬化强化机制

基于CiteSpace的中国污水处理智能控制领域的研究热点与趋势分析

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四川环境 2024年第2期43卷 132-138页

作者：阳鑫张劲冯学高刘志湖北大学资源环境学院武汉430062 湖北大学生态文明建设研究院武汉430062 荆门市生态环境局沙洋分局湖北荆门448200 湖北省生态环境监测中心站武汉430061

为了解我国污水处理过程中智能控制领域的发展现状,厘清该研究领域的热点问题与趋势,通过中国知网数据库,检索了1992—2022年有关污水处理过程中智能控制领域的1688篇研究论文,基于文献计量学,从作者、机构及关键词等方面,应用CiteSpac... 详细信息

为了解我国污水处理过程中智能控制领域的发展现状,厘清该研究领域的热点问题与趋势,通过中国知网数据库,检索了1992—2022年有关污水处理过程中智能控制领域的1688篇研究论文,基于文献计量学,从作者、机构及关键词等方面,应用CiteSpace软件对检索的1688篇文献进行可视化分析,得到相关的知识图谱。结果表明:(1)我国污水处理智能控制研究经历了初步探索阶段、快速发展阶段、波动型发展阶段,波动情况主要受到污水治理政策调控。(2)在污水处理过程的智能化控制研究领域中,北京工业大学的乔俊飞和韩红桂对该领域影响力最大,形成了以北京工业大学为中心的污水处理智能控制科研集聚。(3)污水处理过程中控制技术究热点主要包括基于物联网技术的远程监控和基于遗传算法、粒子群等算法优化神经网络的水质参数软测量以及污水处理过程中的故障诊断,其中,神经网络、模糊控制和遗传算法在污水处理智能控制控制技术中占据主导地位。除此之外,对于污水处理过程中的溶解氧的智能控制是该领域的重要研究课题。

关键词：污水处理智能控制 CiteSpace 文献计量

Oxidation induced ductility enhancement of Zr based metallic glass ribbons in vicinity of glass transition temperature

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China Foundry 2022年第1期19卷 75-80页

作者： Jin-tao Wang xue-feng gao Rui-chun Wang Yin-xiao Wang Fu-yu Dong Wen-ying xue Hong-wang Yang School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China School of Intelligent Manufacturing Weifang University of Science&TechnologyShouguang 262700ShandongChina State Key Lab of Rolling&Automation Northeastern UniversityShenyang 110819China

Zr-based metallic glasses(MGs)possess a wide supercooled liquid region,which gives a wide processing window for superplastic forming to make microdevices with demanding size accuracy and surface *** existence of oxygen may have an influence on the thermoplastic deformation ***,the effect of oxidation on the mechanical behavior of the MGs in the vicinity of glass transition temperature is of great significance for practical forming of MG *** the present study,the effect of oxidation on tensile properties of Zr50Cu40Al10 metallic glass was *** tested samples were characterized by XRD and SEM *** the samples tested in air,the strength decreases 187 MPa,61 MPa and 59 MPa and the ductility increases 0.31,0.36,and 0.77 at 420℃,430℃,and 440℃,respectively,compared with those tested in flowing ***_(2) preferentially formed during the tensile testing at 420℃,and both ZrO_(2) and Al_(2)O_(3) oxides formed at 430℃.The dilution of Zr elements in the remaining amorphous matrix caused by preferential oxidation on the surface layer attributes to the decrease in strength and enhancement in ductility of the Zr_(50)Cu_(40)Al_(10) metallic glasses.

关键词： metallic glass mechanical properties tensile test preferential oxidation high temperature

Strengthening CoCrFeNi high-entropy alloy by Laves and boride phases

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China Foundry 2022年第6期19卷 457-463页

作者： Xiu-gang Chen Gang Qin xue-feng gao Rui-run Chen Qiang Song Hong-zhi Cui School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266500China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

To strengthen the face-centered-cubic(FCC)type CoCrFeNi high-entropy alloy(HEA)by in-situ reinforced phase,(CoCrFeNi)_(100-x)(NbB_(2))_(x)(x=0,2,4,6,8,at.%)alloys were *** constitution,microstructure,tensile mechanical properties of the alloys were studied,and the mechanisms were *** show that the microstructure of all the reinforced alloys consists of the matrix FCC phase,Laves phase,and(Cr_(3)Fe)B_(x) *** eutectic structure and(Cr_(3)Fe)B_(x) phases are formed in the interdendritic region,and the eutectic structure is composed of Laves and FCC *** x increases from 0 to 8,i.e.,with increase of Nb and B elements,the volume fraction of Laves and(Cr_(3)Fe)B_(x) phases increases gradually from 0 to 5.84%and 8.3%,*** testing results show that the ultimate strength of the alloys increases gradually from 409 MPa to 658 MPa,while the fracture strain decreases from 75%to 1.6%.Fracture analysis shows that the crack originates from the(Cr_(3)Fe)B_(x) *** CoCrFeNi alloys are mainly strengthened by the second phase(Laves phase and boride phase).

关键词： high-entropy alloy boride eutectic structure mechanical properties

Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1595-1600页

作者： Qing-feng xue Sheng-gao LU Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition College of Environmental and Resource Sciences Zhejiang University Hangzhou 310027 China

Ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and environmental scanning electron microscopy (ESEM). Ferrospheres in fly ashes show significant iron enrichment compared to their respective fly ashes. Iron oxides in ferrospheres mainly occur as minerals magnetite (Fe3O4) and hematite (α-Fe2O3), which are derived mainly from the decomposition and oxidation of iron-bearing minerals in coal during combustion. EDX data indicate that ferrospheres also contain Si, S, Al and Ca resulting from quartz, mullite, anhydrite and amorphous materials. A large percentage of ferrospheres are commonly 5～50 μm in size. The microstructure of ferrospheres includes smooth, polygonal, dendritic, granular and molten drop characteristics. SEM coupled with EDX provided fast and accurate results of the microstructure and chemical composition of ferrospheres, and helped us to assess environmental issues related to the disposal and utilization of fly ashes.

关键词：飞尘微观结构扫描电子显微技术环境保护

From germline genome to highly fragmented somatic genome:genome-wide DNA rearrangement during the sexual process in ciliated protists

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Marine Life Science & Technology 2024年第1期6卷 31-49页

作者： Liping Lyu xue Zhang Yunyi gao Tengteng Zhang Jinyu Fu Naomi A.Stover feng gao Key Laboratory of Evolution&Marine Biodiversity(Ministry of Education) and Institute of Evolution&Marine BiodiversityOcean University of ChinaQingdao 266003China Department of Biology Bradley UniversityPeoriaIL 61625USA Laoshan Laboratory Qingdao 266237China

Genomes are incredibly dynamic within diverse eukaryotes and programmed genome rearrangements(PGR)play important roles in generating genomic ***,genomes and chromosomes in metazoans are usually large in size which prevents our understanding of the origin and evolution of *** expand our knowledge of genomic diversity and the evolutionary origin of complex genome rearrangements,we focus on ciliated protists(ciliates).Ciliates are single-celled eukaryotes with highly fragmented somatic chromosomes and massively scrambled germline *** in ciliates occurs extensively by removing massive amounts of repetitive and selfish DNA elements found in the silent germline genome dur-ing development of the somatic *** report the partial germline genomes of two spirotrich ciliate species,namely Strombidium *** and Halteria grandinella,along with the most compact and highly fragmented somatic genome for *** provide the first insights into the genome rearrangements of these two species and compare these features with those of other *** analyses reveal:(1)DNA sequence loss through evolution and during PGR in *** has combined to produce the most compact and efficient nanochromosomes observed to date;(2)the compact,transcriptome-like somatic genome in both species results from extensive removal of a relatively large number of shorter germline-specific DNA sequences;(3)long chromosome breakage site motifs are duplicated and retained in the somatic genome,revealing a complex model of chromosome fragmentation in spirotrichs;(4)gene scrambling and alternative pro-cessing are found throughout the core spirotrichs,offering unique opportunities to increase genetic diversity and regulation in this group.

关键词： Alternative processing Ciliates Gene scrambling Genome rearrangement Germline genome Somatic genome

Structure Engineering of Layered Double Hydroxides(LDHs)for Heterogeneous Catalysis

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Chemical Research in Chinese Universities 2024年第4期40卷 590-610页

作者： gao Zhexi MA Haoran WANG Qian LI Dianqing feng Junting DUAN xue State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsBeijing University of Chemical TechnologyBeijing100029P.R.China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou324000P.R.China

Layered double hydroxide(LDH)is regarded as an advanced platform material in catalysis and attracts vast attrition *** a kind of two-dimensional layered material,it exhibits great advantages including cation-tunability in layer,lattice limitation,topological transformation,ion exchange and intercalation *** also can be used as building blocks for composite catalytic *** 100 years,a large number of works have been accomplished and researchers made great progress on investigating the LDH-based catalytic *** this review,we summarize representative achievements and significant progress in recent years,which mainly include constructing high entropy catalytic material,high dispersion/stability and interfacial supported catalytic material,composite catalytic materials and nano-reactor based on ***,through collecting the excellent works,we conclude the future development potential of LDH and provide a perspective.

关键词： Layered double hydroxide(LDH)material Heterogeneous catalysis Structure engineering