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Synthesis and hydrodesulfurization of zirconium binary nitrides

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Chinese Science Bulletin 1997年第15期42卷 1274-1278页

作者： zhang, YJ zhao, XG zhou, zh Yan, WH Ying, PL Xin, q CHINESE ACAD SCI DALIAN INST CHEM PHYSDALIAN 116023PEOPLES R CHINA

As a new material to be used widely in catalytic field, γ-mo2N with high specific surface area(usually, SBET>100 m2·g-1 has recently aroused much attention. Its catalytic activities re-semble those of noble metals （Rh, Pd and Pt） in hydrogenation of hydrocarbon. Especially,it has some marvelous characteristics for deep hydrodesulfurization （HDS）, hydrodeni-

关键词： high surface area binary nitrides hydrodesulfurization H2-TPD.

Study of magnetic and optical properties of Zn1-xTmxTe(Tm = mn,Fe,Co,Ni) diluted magnetic semiconductors：First principle approach

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Chinese Physics B 2017年第2期26卷 452-460页

作者： q mahmood m Hassan m A Faridi Department of Physics University of the Punjab Quaid-e-Azam Campus-54590 Lahore Pakistan Centre for High Energy Physics University of the Punjab Lahore Pakistan

We present structural,magnetic and optical characteristics of Zn_（1-x）Tm_xTe（Tm = mn,Fe,Co,Ni and x = 6.25%）,calculated through Wien2 k code,by using full potential linearized augmented plane wave（FP-LAPW） *** optimization of the crystal structures have been done to compare the ferromagnetic（Fm） and antiferromagnetic（AFm） ground state energies,to elucidate the ferromagnetic phase stability,which further has been verified through the formation and cohesive ***,the estimated Curie temperatures T_c have demonstrated above room temperature ferromagnetism（RTFm） in Zn_（1-x）Tm_xTe（Tm =mn,Fe,Co,Ni and x= 6.25%）.The calculated electronic properties have depicted that mn- and Co-doped ZnTe behave as ferromagnetic semiconductors,while half-metallic ferromagnetic behaviors are observed in Fe- and Ni-doped *** presence of ferromagnetism is also demonstrated to be due to both the p-d and s-d hybridizations between the host lattice cations and Tm *** calculated band gaps and static real dielectric constants have been observed to vary according to Penn＇s *** evaluated band gaps lie in near visible and ultraviolet regions,which make these materials suitable for various important device applications in optoelectronic and spintronic.

关键词： magnetic semiconductors density functional theory optical and dielectric properties electron density of states and band structure of crystalline solids

High mechanical strengths and ductility of stainless steel 304L fabricated using selective laser melting

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Journal of materials Science & Technology 2019年第2期35卷 388-394页

作者： q.B.nguyen Z.zhu F.L.ng B.W.Chua S.m.L.Nai J.Wei Singapore Institute of manufacturing Technology Institute of Research and Development Duy Tan University

Achieving not only high mechanical strengths but also high ductility is recently established using an additive manufacturing technique called selective laser melting. In the present study, stainless steel 304 L fully dense samples were successfully printed using the 3 D systems – ProX 300 printing machine. The ductility and tensile yield strength were almost two and three times higher compared to those of ASTm cast's alloy. Honey comb like nano-cellular structure with different orientation was observed in the fine grains(~4μm) due to fast cooling rate. In addition, the formation of martensite phase in random grains is also a contributor to the strengths. Furthermore, negative residual stresses in the build and horizontal directions were detected and assisted further increase in the tensile strength. Fractography revealed the ductile feature of plastic deformation and the crack openings at unmelted particles or pores.

关键词： Additive manufacturing Stainless steel Powder Selective laser melting

Reliability of quasi integrable and non-resonant Hamiltonian systems under fractional Gaussian noise excitation

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Acta mechanica Sinica 2020年第4期36卷 902-909页

作者： q.F.Lu W.q.zhu m.L.Deng Department of mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is *** rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band ***,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin *** validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from monte Carlo simulation.

关键词： Reliability Fkst passage time quasi integrable and non-resonant Hamiltonian systems Fractional Gauss noise

Gnetifolin K, a New Stilbene Diglucoside from Gnetum parvifolium

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Chinese Chemical Letters 1997年第6期8卷 509-510页

作者： Xu, q Lin, m CHINESE ACAD mED SCI INST MAT MEDBEIJING 100050PEOPLES R CHINA BEIJIng UNION mED COLL BEIJING 100050PEOPLES R CHINA

A new stilbene diglucoside, gnetifolin K, was isolated from the lianas of Gnetum parvifolium. Its structure was established as isorhapotigenin-3,4'-di-O-beta-D-glucoside on the basis of spectral and chemical evidence.

关键词： Gnetifolin K a New Stilbene Diglucoside from Gnetum parvifolium

Stochastic averaging of quasi integrable and resonant Hamiltonian systems excited by fractional Gaussian noise with Hurst index 1/2

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Acta mechanica Solida Sinica 2017年第1期30卷 11-19页

作者： q.F.Lü m.L.Deng W.q.zhu Department of mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrable and resonant Hamiltonian systems under excitation of fractional Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and related fractional Brownian motion （iBm） are briefly introduced. Then, the averaged fractional stochastic differential equations （SDEs） for the first integrals and combinations of angle variables of the associated Hamiltonian systems are derived. The stationary probability density and statistics of the original systems are then obtained approximately by simulating the averaged SDEs numerically. An example is worked out to illustrate the proposed stochastic averaging method. It is shown that the results obtained by using the proposed stochastic averaging method and those from digital simulation of original system agree well.

关键词： quasi integrable and resonant Hamiltonian system Fractional Brownian motion Fractional Gaussian noise Stochastic averaging method Internal resonant

Strain Growth in Containment Vessels

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Transactions of Tianjin University 2006年第B09期12卷 193-198页

作者： DOng q LI q.m.zh.ng J Y School of mechanical Aerospace and Civil Engineering The University of Manchester PO Box 88 Manchester M60 1QD UK Institute of Chemical machinery Zhejiang University Hangzhou 310027 China

Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading. The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage. The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA. The development of bending modes and the interaction between the breathing mode and bending modes are observed. The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels. It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

关键词： strain growth containment vessel dynamic response impulsive loading

Theoretical investigation of optical properties and band gap engineering for Zn1-xTmxTe(Tm=Fe,Co)alloys by modified Becke-Johnson potential

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Chinese Physics B 2017年第8期26卷 491-498页

作者： q mahmood m Yaseen m Hassan Shahid m Ramay Asif mahmood materials Growth and Simulation Laboratory Department of PhysicsUniversity of the PunjabQuaid-i-Azam Campus54590LahorePakistan Department Of Physlcs University of Agriculture UniversityFaisalabad 38040Pakistan Physics and Astronomy Department College of ScienceKing Sand UniversityRiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The direct band gap ZnTe with transition metal （Tm） impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson （mBJ） functional for performing the structural computations and detailed investigations of the optical characters in Zn1_xTmxTe （Tm = Fe, Co） alloys with 0 ≤ x ≤1. By employing the FP-LAPW method, we determine various optical parameters for the ternary alloys and for the end binaries. The calculated static dielectric constants and optical band gaps for Zn1_xTmxTe （Tm = Fe, Co） have an inverse relation that verifies the Penn model. We find that the static dielectric constant is nearly equal to the square of the static refractive index, and both increase with Tm content. Furthermore, we also find a slight shift of peaks to a higher energy region with increasing Tm concentration. The decreasing band gap and high value of the absorption in the visible region of electromagnetic spectrum make these alloys suitable for photonic and solar cell applications.

关键词： amorphous semiconductors transition metal-doped ZnTe structural computation optical property

COSET DIAGRAmS FOR A HOmOmORPHIC ImAGE OFΔ(3,3,k)

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Acta mathematica Scientia 2008年第2期28卷 363-370页

作者： m.Ashiq q.mushtaq Department of Basic Sciences and Humanities College of E and mE National University of Sciences and Technology RawalpindiPakistan Department of mathematics quaid-i-Azam University IslamabadPakistan

Let q be a prime power. By PL（Fq） the authors mean a projective line over the finite field Fq with the additional point ∞. In this article, the authors parametrize the conjugacy classes of nondegenerate homomorphisms which represent actions of △（3, 3, k） = （u, v： u^3 = v^3 = （uv）^k = 1〉on PL（Fq）, where q ≡ ±1（modk）. Also, for various values of k, they find the conditions for the existence of coset diagrams depicting the permutation actions of △（3, 3, k） on PL（Fq）. The conditions are polynomials with integer coefficients and the diagrams are such that every vertex in them is fixed by （u^-v^-）^k. In this way, they get △（3, 3, k） as permutation groups on PL（Fq）.

关键词： Coset diagrams conjugacy classes nondegenerate homomorphism projec tire line and triangle groups