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Analysis of destructive effect of Zn on carbon brick and way of Zn into carbon brick

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1344-1354页

作者： Peng-bo Liu Shu-sen cheng yu-qing Xue Xiao-man cheng Zhao Liu University of Science and Technology Beijing Beijing 100083China ministry of Ironmaking Shangdong Taishan Steel Group Co.Ltd.Taian 271000ShandongChina

The service life of a blast furnace depends largely on the degree of damage to the carbon brick in the *** brick and ramming material in the hearth of a 1780 m3 blast furnace after shutdown were sampled and *** was found that the substances in the cracks of the carbon brick near and above the taphole were ZnO and Zn_(2)SiO_(4),whereas the substances in the cracks of the carbon brick below the taphole were *** reaction of Zn with CO,SiO_(2),and Fes generates ZnO,Zn_(2)SiO_(4),and ZnS,resulting in volume expansion,which is an important reason for the cracking of carbon ***,several obvious Zn vapor flow channels were found in the ramming material,through which Zn vapor could enter the carbon brick,causing damage to the carbon *** the compactness of the ramming material is beneficial to preventing Zn vapor from entering the carbon brick through the voids in the ramming material,reducing the destructive effect of Zn on the carbon brick and further extending the service life of the blast furnace.

关键词： Zn Blast furnace Carbon brick Ramming material Crack

The minimum Centroid Branch Spanning Tree Problem

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Journal of the Operations Research Society of China 2024年第2期12卷 528-539页

作者： Hao Lin cheng He School of Science Henan University of TechnologyZhengzhou450001HenanChina

For a spanning tree T of graph G,the centroid of T is a vertex v for which the largest component of T-v has as few vertices as *** number of vertices of this component is called the centroid branch weight of *** minimum centroid branch spanning tree problem is to find a spanning tree T of G such that the centroid branch weight is *** application to design of communication networks,the loads of all branches leading from the switch center should be as balanced as *** this paper,we prove that the problem is strongly NP-hard even for bipartite ***,the problem is shown to be polynomially solvable for split graphs,and exact formulae for special graph familis,say Kn_(1),n_(2),...,n_(k)and P_(m)×P_(n),are presented.

关键词： Spanning tree optimization Centroid branch-NP-hardness Polynomial-time algorithm

Achieving superior performance in powder-metallurgy near-βtitanium alloy by combining hot rolling and rapid heat treatment followed by aging

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Journal of materials Science & Technology 2024年第4期171卷 24-36页

作者： Fucheng Qiu Tuo cheng yuchao Song Orest m.Ivasishin Dmytro G.Savvakin Guangyu ma Huiyan Xu College of materials Science and Engineering Jilin UniversityChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130025China G.V.Kurdy.m.v Institute for metal Physics KyivUkraine College of Biological and Agricultural Jilin UniversityChangchun 130025China

Heat treatment plays an important role in tailoring the mechanical properties of powder-metallurgy(Pm)titanium ***,only limited work about the rapid heat treatment(RHT)of Pm titanium alloys has been *** this work,RHT was applied to Pm Ti-5Al-5mo-5V-1Cr-1Fe alloy after hot rolling to study the evolution of its mechanical properties and the influence of residual pores on its *** hot rolling and annealing,a fine and uniformα+βstructure with few residual pores is *** RHT,the primaryαdissolves gradually and completes in theβregion,and theβgrains then grow,resulting in the continuous decrease in elongation after ***,the tensile strength first increases and then decreases with increasing RHT temperature,owing to the increase in volume fraction of secondaryαinα+βregion and theβgrain growth inβ*** contrast to the RHT of cast-and-wrought titanium,the negative influence of residual pores lowers the RHT temperature for obtaining the highest tensile strength to a temperature below theβ-transus *** the negative influence of the residual pores,retained primaryαand fineβgrains with fine secondaryαinside contribute to achieving a good strength/ductility balance(1570 mPa and 6.1%,respectively).Addi-tionally,although at higher cycles to failure,the negative influence of residual pores increases as it affects the crack initiation zone at the subsurface,the good resistance of secondaryαto fatigue crack propaga-tion still enhances the fatigue strength considerably(about 300 mPa).This work suggests a cost-effective strategy to produce titanium alloys with high performance.

关键词： Rapid heat treatment Powder metallurgy mechanical properties Near-βtitanium Residual pores

Towards a blood ecosystem approach to dissect systemic diseases

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Science China(Life Sciences) 2024年第7期67卷 1528-1531页

作者： Hong Wang Tao cheng State Key Laboratory of Experimental Hematology Haihe Laboratory of Cell EcosystemNational Clinical Research Center for Blood DiseasesInstitute of Hematology&Blood Diseases HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300020China Tianjin Institutes of Health Science Tianjin 301600China

Systemic diseases,in contrast to localized ailments,exert widespread effects and can impact the entire *** of systemic diseases encompass autoimmune disorders,infectious diseases,metabolic disorders,and chronic conditions like *** diseases often entail intricate interactions among diverse organs,tissues,and physiological systems,influenced by a myriad of factors.

关键词： diseases organs autoimmune

Rational Schur Superalgebras

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Algebra Colloquium 2024年第2期31卷 209-220页

作者： Andrew Riesen Shun-Jen cheng Department of mathematical and Statistical Sciences University of Alberta 1132489 Ave NWEdmontonAlbertaCanada 不详

We develop and study the generalization of rational Schur algebras to the super *** to the classical case,this provides a new method for studying rational supermodules of the general linear supergroup GL(m|n).Furthermore,we establish a Schur-Weyl duality result for rational Schur superalgebras and conclude that under certain conditions these objects will be semisimple.

关键词： Schur algebra supermathematics general linear supergroup

Compound Product of Hypermatrices

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Journal of Systems Science & Complexity 2024年第1期37卷 169-183页

作者： cheng Daizhan mENG min ZHANG Xiao JI Zhengping Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Department of Control Science and Engineering School of Electronics and Information EngineeringTongji UniversityShanghai 201210China National Center for mathematics and Interdisciplinary Sciences Chinese Academy of SciencesBeijing 100190China School of mathematical Sciences University of Chinese Academy of SciencesBeijing 100149China.

The semi-tensor product(STP)of matrices is generalized to multidimensional arrays,called the compound product of *** product is first defined for three-dimensional hypermatrices with compatible orders and then extended to general *** different types of hyperdeterminants are introduced and certain properties are *** Lie groups and Lie algebras corresponding to the hypermatrix products are ***,these results are applied to dynamical systems.

关键词： Compound semi-tensor product hyperdeterminants hypereigenvalues and hypereigenvectors hypergeneral linear groups hypermatrices.

Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

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Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： Liang cheng Xiaolei CHEN Zhisen yE yongjun ZHANG State Key Laboratory of Precision Electronic manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced manufacturing Technology of marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. Simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

Strong,tough,and thermally conductive nacre-inspired boron nitride nanosheet/epoxy layered nanocomposites

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Nano Research 2024年第2期17卷 820-828页

作者： Huagao Wang Rongjian Lu Lei Li cheng Liang Jia yan Rui Liang Guoxing Sun Lei Jiang Qunfeng cheng School of Chemistry Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of EducationBeihang UniversityBeijing 100191China School of Chemistry and materials Science University of Science and Technology of ChinaHefei 230026China Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China Department of Stomatology Fifth Medical CenterChinese PLA General HospitalBeijing 100039China Department of Engineering Science Faculty of Innovation EngineeringMacao University of Science and TechnologyAvenida Wai LongTaipaMacao 999078 China Joint Key Laboratory of the ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoAvenida da UniversidadeTaipaMacao 999078China Institute of Energy.m.terials Science(IEmS) University of Shanghai for Science and TechnologyShanghai 200093China

Thermally conductive polymer nanocomposites integrated with lightweight,excellent flexural strength,and high fracture toughness(KIc)would be of great use in many ***,achieving all of these properties simultaneously remains a great *** by natural nacre,here we demonstrate a lightweight,strong,tough,and thermally conductive boron nitride nanosheet/epoxy layered(BNNEL)*** of the layered structure and enhancing the interfacial interactions through hydrogen bonding and Si–O–B covalent bonding,the resulting nacre-inspired BNNEL nanocomposites show high fracture toughness of~4.22 mPa·m^(1/2),which is 7 folds as high as pure ***,the BNNEL nanocomposites demonstrate sufficient flexural strength(~168.90 mPa,comparable to epoxy resin),while also being lightweight(~1.23 g/cm^(3)).Additionally,the BNNEL nanocomposites display a thermal conductivity(κ)of~0.47 W/(m·K)at low boron nitride nanosheet loading of 2.08 vol.%,which is 2.7 times higher than that of pure epoxy *** developed nacre-inspired strategy of layered structure design and interfacial enhancement provides an avenue for fabricating high mechanical properties and thermally conductive polymer nanocomposites.

关键词： nacre-inspiration nanocomposites flexural strength fracture toughness(KIc) thermal conductivity

Bed inventory balance and stability of dual circulating fluidized bed systems

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Particuology 2024年第1期84卷 98-106页

作者： yangjun Wei Leming cheng David Pallares Bo Leckner Institute for Thermal Power Engineering State Key Laboratory of Clean Energy UtilizationZhejiang UniversityHangzhou310027China Department of Space Earth and EnvironmentChalmers University of TechnologyS-41296GöteborgSweden

Experiments and modelling are conducted for general understanding on the imbalance phenomenon and for discussion on the strategies to improve the bed inventory balance and stability of a dual circulating fluidized bed(DCFB)*** experiments are carried out in a 15.5 m high pilot-scale DCFB cold test system.A fluid-dynamic DCFB model is developed based on a 1.5-dimensional semi-empirical model of an industrial CFB boiler,validated by experimental *** effects of control methods and operation conditions on the bed inventory balance and on the stability of the pilot-and large-scale DCFB systems are discussed.A"stable-unbalanced"state,where the system reaches a steady state,consisting of un-balanced bed inventories,is observed in both experiments and model *** maintain a balanced state and similar bed inventory in the DCFB systems with similar cross-sectional areas,it is recom-mended to keep similar total pressure drops or gas velocities in both reactors.

关键词： Bed inventory balance Stability Dual circulating fluidized bed(DCFB) Experiment modelling