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Phase transition in the Zr_(60)Al_(15)Ni_(25) bulk metallic glass subjected to rolling at room temperature

science China(Technological sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2, LI Jinfu1, ZHOU Yaohe1 & WU Yanqing3 1. State Key Laboratory of Metal Matrix Composites, school of Materials science and engineering, Shanghai Jiao Tong University, Shanghai 200030, China 2. school of Materials science and engineering, Taiyuan University of science and Technology, Taiyuan 030024, China 3. school of Environmental science and engineering, Shanghai Jiao Tong University, Shanghai 200030, China State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai China school of Materials science and engineering Taiyuan University of Science and Technology Taiyuan China school of Environmental science and engineering Shanghai Jiao Tong University Shanghai China

The microstructure evolution of the Zr60Al15Ni25 metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 20%, the values of FWHM; ΔH are lower than that of the as-cast state. When reaches 30%, the values of FWHM; ΔH become larger than that of the as-cast state, while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

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Effects of Fe-Oxide and Mg Layer Insertion on Tunneling Magnetoresistance Properties of CoFeB/MgO/CoFeB Magnetic Tunnel Junctions

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Chinese Physics Letters 2016年第11期33卷 124-126页

作者：娄永乐张玉明郭辉徐大庆张义门 school of Microelectronics Xidian University school of Electrical and Control engineering Xi'an University of Science and Technology

To study the influence of CoFeB/MgO interface on tunneling magnetoresistance （TMR）, different structures of magnetic tunnel junctions （MTJs） are successfully prepared by the magnetron sputtering technique and characterized by atomic force microscopy, a physical property measurement system, x-ray photoelectron spectroscopy, and transmission electron microscopy. The experimental results show that TMR of the CoFeB/Mg/MgO/CoFeB structure is evidently improved in comparison with the CoFeB/MgO/CoFeB structure because the inserted Mg layer prevents Fe-oxide formation at the CoFeB/MgO interface, which occurs in CoFeB/MgO/CoFeB MTJs. The inherent properties of the CoFeB/MgO/CoFeB, CoFeB/Fe-oxide/MgO/CoFeB and CoFeB/Mg/MgO/CoFeB MTJs are simulated by using the theories of density functions and non-equilibrium Green functions. The simulated results demonstrate that TMR of CoFeB/Fe-oxide/MgO/CoFeB MTJs is severely decreased and is only half the value of the CoFeB/Mg/MgO/CoFeB MTJs. Based on the experimental results and theoretical analysis, it is believed that in CoFeB/MgO/CoFeB MTJs, the interface oxidation of the CoFeB layer is the main reason to cause a remarkable reduction of TMR, and the inserted Mg layer may play an important role in protecting Fe atoms from oxidation, and then increasing TMR.

关键词： MgO of TMR Fe Effects of Fe-Oxide and Mg Layer Insertion on Tunneling Magnetoresistance Properties of CoFeB/MgO/CoFeB Magnetic Tunnel Junctions in is that on

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Optimization on temperature efficiency and switch time of thin-walled regenerator with perturbation analysis

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Journal of Central South University of Technology 2006年第5期13卷 506-510页

作者：艾元方梅炽蒋绍坚黄国栋陈红荣 school of Energy science and engineering Central South University

The heat transfer characteristic of honeycomb ceramic regenerator was optimized by the perturbation analytical-numerical method. The results show that there is a temperature efficiency peak and the corresponding optimal switch time. The decrease of air oxygen concentration leads to the decrease of maximum temperature efficiency. Optimal switch time is directly proportional to the matrix thickness. The solid heat conduction along the flow direction and the regenerator heat storage capacity of the unit volume have no impact on maximum temperature efficiency and optimal switch time. The temperature efficiency tendency based on the semi-analysis is the same as dispersion combustion tests with low oxygen concentration, and optimal switch time of 2-4 s agrees well with that of 4 s in high-temperature gasification tests. The possibility of design, operate and control a thin-walled regenerator with high efficiency by means of the perturbation method is proved.

关键词： thin-walled regenerator perturbation temperature efficiency switch time

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Numerical simulation of temperature and velocity fields in plasma spray

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Journal of Central South University of Technology 2007年第4期14卷 496-499页

作者：范群波王鲁王富耻 school of Materials science and engineering Beijing Institute of Technology

Based on the turbulence jet model, with respect to Ar-He mixture plasma gas injecting to ambient atmosphere, the temperature filed and velocity field under typical working conditions were investigated. Given the conditions of I=900 A, FAr= 1.98 m^3/h, FEe=0.85 m^3/h, it is found that both the temperature and the velocity undergo a plateau region near the nozzle exit （0-10 mm） at the very first stage, then decrease abruptly from initial 13 543 K and 778.2 m/s to 4 000 K and 260.0 m/s, and finally decrease slowly again. Meanwhile, the radial temperature and radial velocity change relatively slow. The inner mechanism for such phenomena is due to the complex violent interaction between the high-temperature and high-velocity turbulent plasma jet and the ambient atmosphere. Compared with traditional methods, the initial working conditions can be directly related to the temperature and velocity fields of the plasma jet by deriving basic boundary conditions.

关键词： plasma spray plasma jet temperature field velocity field

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Effect of electrolysis superheat degree on anticorrosion performance of 5Cu/(10NiO-NiFe_2O_4) cermet inert anode

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Journal of Central South University of Technology 2007年第6期14卷 768-772页

作者：王家伟赖延清田忠良刘业翔 school of Metallurgical science and engineering Central South University

5Cu/(10NiO-NiFe2O4) cermet inert anodes were prepared by cold-pressing and sintering process, and the effect of superheat degree of melting K3AlF6-Na3AlF6-AlF3 on their anticorrosion performance was studied under electrolysis conditions. The results show that, the fluctuation of cell becomes small with increasing of superheat degree, which is helpful to inhibit the formation of cathodic encrustation; the concentration of impurities from inert anode in bath goes up to certain degree, but it is far smaller than those in traditional high-temperature bath. Increasing the superheat degree of melting K3AlF6-Na3AlF6-AlF3 has unconspicuous effect on the contents of impurities in cathodic aluminum. The total mass fractions of Fe, Ni and Cu in aluminum are 15.38% and 15.09% respectively under superheat degree of 95 and 195 ℃. From micro-topography of anode used view, increasing the superheat degree can aggravate corrosion of metal Cu in inert anode, and has negative influence on electrical conductivity of electrode to some extent.

关键词： cermets inert anode aluminum electrolysis electrolysis corrosion superheat degree

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Synthesis and Crystal Structure of 1-(3'-Amino-2',4',6'-trinitrophenyl)-4,5-dinitroimidazole

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Chinese Journal of Structural Chemistry 2013年第6期32卷 823-826页

作者：侯可辉刘祖亮 school of Chemical engineering Nanjing University of Science and Technology

1-（3＇-Amino-2＇,4＇,6＇-trinitrophenyl）-4,5-dinitroimidazole was structurally determined by single-crystal X-ray diffraction. The title compound belongs to the monoclinic system, space group P212121 with a = 8.4941（7）, b = 12.7651（10）, c = 13.3699（12）A, V= 1449.7（2） A3, Z = 4, Dc = 1.760 g/cm^3, p = 0.162 mm^-1, F（000） = 776, R = 0.0780 and wR = 0.1453.

关键词： N-aryl-C-dinitroimidazole single crystal synthesis

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Influence of Rare Earth Co-dopant on the Photocatalytic Property of TiO_2 Nano-particles

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Journal of Wuhan University of Technology(Materials science) 2010年第3期25卷 370-374页

作者：徐晓虹 school of Materials science and engineering Wuhan University of Technology

A series of nanometer TiO2 photocatalysts co-doped respectively with rare earth Er^3＋-Ce^3＋ and La^3＋-Fe^3＋ were prepared by sol-gel method,and the photocatalytic activity under ultra-violet light was evaluated by photocatalytic degradation of methyl *** crystallographic forms,particles size,and morphology were characterized by XRD and *** results showed that the optimum heat temperature of co-doped TiO2 was 550 ℃,and the co-doped TiO2 kept *** anatase crystal had the average size of 20 *** co-doping caused red-shift of the UV-Vis absorption spectra and enhanced the absorption of *** with the spectrum of pure TiO2 photocatalysts,the red-shift of Er^3＋-Ce^3＋ co-doping and La^3＋-Fe^3＋ co-doping catalysts was 53 nm and 34 nm,*** co-doping amount for Er^3＋-Ce^3＋ was n（Er^3＋）：n（TiO2）=0.1%,n（Ce^3＋）：（TiO2）= 0.05% and La^3＋-Fe^3＋ was n（La^3＋）：n（TiO2）=0.05%,n（Fe^3＋）：（TiO2）=0.5%.Under the condition the photocatalysis properties of the samples can be *** was found that the catalytic activity correlated well with the *** degradation rate of methyl blue examined at two hour of the reaction was 92.37%,and the better photocatalysis properties than the non-doped TiO2 were *** co-doped photocatalyst on methyl blue degradation follows the apparent first-order kinetics.

关键词： nano-TiO2 rare earth co-doped photocatalytic degradation sol-gel method

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The Microstructure and Properties of Diffusion Layer of Spray Aluminum

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Journal of Wuhan University of Technology(Materials science) 2005年第3期20卷 81-83页

作者：叶宏 school of Materials science and engineering Chongqing Institute of Technology

After diffusion processing of thermal spraying , aluminum on 20^# steel is discussed in this article. Variations of microstructure, composition as well as mierohardness and corrosion resistatwe of diffusion layer of spray aluminum were explored by means of X-ray diffraction, scanning electron microscopy （SEM） and electron probe microanlysis （ EPMA ） . The result shows that the diffusion layer of spray aluminum consists of η phase （ Fe2Al5 ）, ξ phuse （ FeAl2 ）, β2 phase （ FeA1 ）,β1 plmse （ Fe3Al ） and α pluse from surface to substrate. There are balanced transitions between phases. The layer has extra high hardness and corrosion resistance.

关键词： spray aluminum diffusion microstructure composition properties

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Ext-ICAS:A Novel Self-Normalized Extractive Intra Cosine Attention Similarity Summarization

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Computer Systems science & engineering 2023年第4期45卷 377-393页

作者： P.Sharmila C.Deisy S.Parthasarathy Deparment of Information Technology Thiagarajar College of EngineeringMaduraiIndia Deparment of data science Thiagarajar College of EngineeringMaduraiIndia

With the continuous growth of online news articles,there arises the necessity for an efficient abstractive summarization technique for the problem of information *** summarization is highly complex and requires a deeper understanding and proper reasoning to come up with its own summary *** summarization task is framed as seq2seq *** seq2seq methods perform better on short sequences;however,for long sequences,the performance degrades due to high computation and hence a two-phase self-normalized deep neural document summarization model consisting of improvised extractive cosine normalization and seq2seq abstractive phases has been proposed in this *** novelty is to parallelize the sequence computation training by incorporating feed-forward,the self-normalized neural network in the Extractive phase using Intra Cosine Attention Similarity(Ext-ICAS)with sentence dependency ***,it does not require any normalization technique *** proposed abstractive Bidirectional Long Short Term Memory(Bi-LSTM)encoder sequence model performs better than the Bidirectional Gated Recurrent Unit(Bi-GRU)encoder with minimum training loss and with fast *** proposed model was evaluated on the Cable News Network(CNN)/Daily Mail dataset and an average rouge score of 0.435 was achieved also computational training in the extractive phase was reduced by 59%with an average number of similarity computations.

关键词： Abstractive summarization natural language processing sequence-tosequence learning(seq2seq) self-normalization intra(self)attention

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Effect of CaO doping on mechanical properties and thermal shock resistance of 10NiO-NiFe_2O_4 composite ceramics

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Journal of Central South University of Technology 2008年第1期15卷 25-28页

作者：赖延清张勇张刚田忠良李劼 school of Metallurgical science and engineering Central South University

The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.

关键词： mechanical property thermal shock resistance CaO doping 10NiO-NiFe2O4 inert anode

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