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Static Recrystallization Behavior of Hot Deformed Austenite for Micro-Alloyed Steel

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Journal of Materials Science & Technology 2003年第Z1期19卷 117-118页

作者： Jie huang Zhou XU Xin xing Key Laboratory for High Temperature Materials and Tests of Ministry of Education Shanghai Jiaotong UniversityShanghai 200030 China Key Laboratory for High Temperature Materials and Tests of Ministry of Education Shanghai Jiaotong UniversityShanghai 200030 China Key Laboratory for High Temperature Materials and Tests of Ministry of Education Shanghai Jiaotong UniversityShanghai 200030 China

Static recrystallization behavior of austenite for micro-alloyed steel during hot rolling was studied and the influence (τ-ε diagram) of holding time and deformation at different deformations and isothermal temperatures on microstructuralstate of austenite were discussed. Corresponding to parameter Z in the dynamic recrystallization diagram, parameterY was then introduced to simplify static recrystallization diagrams.

关键词： Micro-alloyed steel, Hot deformation of austenite, Static recrystallization

Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

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Journal of Materials Science & Technology 2006年第6期22卷 775-778页

作者： Zhifu huang Jiandong xing Anfeng ZHANG School of Material＇s Science and Engineering Xi＇an Jiaotong University Xi＇an 710049 China School of Mechanical Engineering Xi＇an Jiaotong University Xi＇an 710049 China

In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method （SC-CCM）, and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138% more than that of the hypereutectic high Cr one prepared by conventional casting method.

关键词： Slope cooling body-centrifugal casting method Hypereutectic high Cr cast iron Primary carbides Microstructure Impact toughness

High-Efficiency Graphene Photo Sensor Using a Transparent Electrode

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Chinese Physics Letters 2011年第10期28卷 192-194页

作者： LIU tao huang Zheng National Key Laboratory for Electronic Measurement Technology and Key Laboratory of Instrumentation Science and Dynamic Measurement North University of ChinaTaiyuan 030051 Xi'an Institute of Electromechanical Information Technology Xi'an 710065

We report the first implementation of transparent electrodes in bottom-gate graphene transistors used for photo *** to conventional nontransparent electrodes,the transparent electrodes allow photons to transmit through to the graphene beneath,providing an enlarged absorption area and thereby giving rise to an enhancement of photocurrent *** devices are fabricated with an asymmetric metallization scheme and the experimental results show that the maximum photocurrent density using the transparent electrodes(ITO and Pd/ITO)is over two times higher than that using the nontransparent electrodes(Ti and Pd),indicating a significant enhancement in the performance of graphene photo sensors.

关键词： transparent thereby asymmetric

Nanosized Rh grown on single-walled carbon nanohorns for efficient methanol oxidation reaction

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Rare Metals 2022年第6期41卷 2108-2117页

作者： Xiang-Jie Guo Qi Zhang Ya-Nan Li Yang Chen Lu Yang Hai-Yan He xing-tao Xu Hua-Jie huang Collegeof Mechanics and Materials Hohai University Nanjing 210098China International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials ScienceIbaraki 305-0044Japan

Reasonable design and controllable synthesis of non-Pt catalysts with high methanol oxidation activity are regarded as a valid way to promote the large-scale com-mercial applications of direct methanol fuel cells(DMFCs).Herein,we develop a convenient and cost-ef-fective approach to the successful fabrication of nanosized Rh grown on single-walled carbon nanohorns(Rh/SWCNH)as anode catalysts for *** unique architectural configuration endows the as-obtained hybrids with a series of intriguing structural merits,including large specific surface areas,abundant opened holes,optimized electronic structures,homogeneous Rh dispersion,and good electrical *** a consequence,the resulting Rh/SWCNH catalysts exhibit exceptional elec-trocatalytic properties in terms of a large electrochemically active surface area of 102.5 m^(2)·g^(-1),a high mass activity of 784.0 mA·mg^(-1),as well as reliable long-term durability towards the methanol oxidation reaction in alkaline media,thereby holding great potential as alternatives for com-mercial Pt/carbon black and Pd/carbon black catalysts.

关键词： Rhodium Carbon nanohorns Electrocatalysts Methanol oxidation Fuel cells

Frequency-dependent reflection of elastic wave from thin bed in porous media

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Chinese Physics B 2020年第6期29卷 249-254页

作者： Hong-xing Li Chun-Hui tao Cai Liu Guang-Nan huang Zhen-An Yao State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China Department of Geophysics Jilin UniversityChangchun 130026China

The reflection of elastic wave from thin bed in porous media is important for oil and gas reservoir seismic *** equations for calculating frequency-dependent reflection amplitude versus incident angle(FDAVA)from thin bed in porous media are obtained based on porous media *** conclusions are obtained from numerical analysis,specifically,slow compression wave may be ignored when considering boundary conditions in most situations;the dispersion of reflection from thin bed is much higher than that from thick layer and is periodic in frequency domain,which is affected by the thickness of thin bed,velocity,and incident angle;the reflection amplitude envelope in frequency domain decays exponentially,which is affected by the thickness of thin bed,attenuation,and incident angle;the reflection amplitude increases with thickness of thin bed increasing,and then it decreases when the thickness reaches to a quarter of wavelength.

关键词： frequency-dependent reflection porous media thin bed reservoir

Tunable band structures of polycrystalline graphene by external and mismatch strains

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Acta Mechanica Sinica 2012年第6期28卷 1539-1544页

作者： Jiang-tao Wu xing-Hua Shi Yu-Jie Wei LNM Institute of Mechanics Chinese Academy of Sciences

Lacking a band gap largely limits the application of graphene in electronic devices. Previous study shows that grain boundaries （GBs） in polycrystalline graphene can dra- matically alter the electrical properties of graphene. Here, we investigate the band structure of polycrystalline graphene tuned by externally imposed strains and intrinsic mismatch strains at the GB by density functional theory （DFT） calcu- lations. We found that graphene with symmetrical GBs typ- ically has zero band gap even with large uniaxial and biax- ial strain. However, some particular asymmetrical GBs can open a band gap in graphene and their band structures can be substantially tuned by external strains. A maximum band gap about 0.19 eV was observed in matched-armchair GB （5, 5） I （3, 7） with a misorientation of θ = 13° when the applied uniaxial strain increases to 9%. Although mismatch strain is inevitable in asymmetrical GBs, it has a small influence on the band gap of polycrystalline graphene.

关键词： Graphene Grain boundary Defects Strain and gap

Pryce's mass-center operators and the anomalous velocity of a spinning electron

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Science China(Physics,Mechanics & Astronomy) 2018年第8期61卷 1-7页

作者： Long huang XiaoHua Wu tao Zhou College of Physical Science and Technology Sichuan University School of Physical Science and Technology Southwest Jiaotong University

In the present work, we develop a method to derive the anomalous velocity of a spinning electron. From Dirac equation, the relationships among the expectation values of the Pryce's mass-center operator, the position operator, the spin operator and the canonical momentum operator are investigated. By requiring that the center of mass for a classical spinning electron is related to the expectation value of Pryce's mass-center operator, one can obtain a classical expression for the position of the *** the classical equations of motion, the anomalous velocity of a spinning electron can be easily obtained. It is shown that two factors contribute to the anomalous velocity: one is dependent on the selection of Pryce's mass-center operators and the other is a type-independent velocity expressed by the rotational velocity and the Lorentz force.

关键词： mass-center operator anomalous velocity Foldy-Wouthuysen transformation

Quantifying the influence of magmatism and tectonism on ultraslow-spreading-ridge hydrothermal activity:Evidence from the Southwest Indian Ridge

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Geoscience Frontiers 2023年第5期14卷 39-54页

作者： xing Xu Shili Liao Chunhui tao Lushi Liu School of Oceanography Shanghai Jiaotong UniversityShanghai 200030China Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Northeast Institute of Geography and Agroecology CASChangchun 130102China

Hydrothermal activity in mid-ocean ridges(MORs)is an important intermediary for the mass and heat exchange between the ocean and *** development of hydrothermal activity on MORs is primarily controlled by coupled magmatic and tectonic *** ultraslow-spreading ridges,deepdipping low-angle normal faults with large offsets,typically detachment faults in the inside corners of ridge offsets,favor the formation of tectonic-related hydrothermal activities,whereas volcanic-related hydrothermal fields are typically developed in neovolcanic zones in this category of the ridge ***,whether tectonic or magmatic activity is dominant and to what extent they control the formation of hydrothermal activities on ultraslow-spreading ridges remain *** in the west and east of the Gallieni transform fault(TF)located in the ultraslow-spreading Southwest Indian Ridge(SWIR),namely,western area(WA)and eastern area(EA),exhibit distinct magma-supply conditions that provide favorable conditions for examining the influence of magmatic and tectonic *** generated prediction models for these areas using the spatial analysis of the water depth,minor faults,large faults,ridge axis,nontransform discontinuity(NTD)inside corners,TF inside corners,Bouguer gravity anomaly,magnetic anomalies,and seismic *** employing the weights of evidence method,we reported that the formation of seafloor hydrothermal systems in SWIR was primarily correlated to the NTD inside corner,ridge axis,and minor fault(i.e.,contrast values(C)of 4.186,3.727,and 3.482 in WA and 4.278,3.769,and 3.135 in EA).Furthermore,EA was significantly affected by the TF inside corner(C=3.501),whereas WA was influenced by large faults(C=4.062).Our results demonstrated that tectonism was the primary controlling factor in the development of hydrothermal activities in the study area,and the contribution of magmatism was secondary,even in WA,which has a relatively robust magma *** d

关键词： Southwest Indian Ridge Hydrothermal activity Weights of evidence Spatial analysis Magmatism and tectonism

Joint estimation of DOA, frequency, and polarization based on cumulants and UCA

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Journal of Systems Engineering and Electronics 2007年第4期18卷 704-709页

作者： huang Jiacai Shi Yaowu tao Jianwu Automation Dept. Nanjing Institute of Technology Nanjing 211167 P. R. China Coll. of Communication Jilin Univ. Changchun 130025 P. R. China Univ. of Aeronautics Changchun 130022 P R. China

A joint estimation algorithm of direction of arrival （DOA）, frequency, and polarization, based on fourth-order cumulants and uniform circular array （UCA） of trimmed vector sensors is presented for narrowband non-Gaussian signals. The proposed approach, which is suitable for applications in arbitrary Gaussian noise environments, gives a closed-form representation of the estimated parameters, without spectral peak searching. An efficient method is also provided for elimination of cyclic phase ambiguities. Simulations are presented to show the performance of the algorithm.

关键词： polarization direction of arrival frequency fourth-order cumulant uniform circular array vector sensor