材料期刊网

Synthesis of Nanocrystalline FeS2 with Increased Band Gap for Solar Energy Harvesting

Somnath Middya , Animesh Layek , Arka Dey , Partha Pratim Ray

材料科学技术（英文）

关键词:

Surface Yielding of Metals by X-ray Diffraction

Xiuying GAI Jiabao LI Zengqiao KANG State Key Lab.for Fatigue and Fracture of Materials , Institute of Metal Research , Academia Sinica , Shenyang , 110015 , ChinaJiawen HE Xi'an Jiaotong University , Xi'an , 710049 , China

材料科学技术（英文）

Surface yielding of metallic material was measured with strain gage and X-ray diffraction methods. The results show that.when the residual stress in the transverse direction is involved,the surface yield strength should be evaluated with biaxial Mises criterion.For a medium carbon high strength steel, the yield strength of the bulk material is 581 MPa and the surface yield strengths for 0.05% and 0.1%plastic strain are about 436 MPa and 463 MPa respectively.The 0.05% yield strength will approximately increase to 788 MPa after shot peening.In the early stage of plastic deformation, strain hardening in the surface layer is quite different from that of the bulk sample.

关键词: biaxial stress , null , null , null

STUDY OF RAY IRRADIATION ON DIAMOND-LIKE CARBON FILMS

G.A.Liu

金属学报(英文版)

Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (rf) plasma deposition method, γ-ray, ultraviolet (UV) ray were used toirradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were usedto characterize the changing characteristics of SP3 C-H bond and hydrogen content inthe films due to the irradiations. The results show that, the damage degrees induced bythe UV ray on the SP3 C-H bonds are much stronger than that by the γ-ray. When theirradiation dose of γ-ray reaches 10× 104Gy, the SP3 C-H bond reduces about 50% innumber. The square electrical resistance of the films is reduced due to the irradiationof UV ray and this is caused by severe oxidation of the films. By using the results onoptical gap of the films and the fully constrained network theory, the hydrogen contentin the as-deposited films is estimated to be 10-25at.%.

关键词: diamond-like carbon film , null , null

STRESS CORRECTION FOR REMOVAL OF MATERIAL IN X-RAY STRESS DETERMINATION

Journal of Testing and Evaluation

To determine residual stresses in a (flat) plate or bar with a rectangular cross-section by X-ray diffraction after removal of material, we can sectionally approximate the measured stress curve with depth using power series, then consequently evaluate the additional stresses created by removal, and finally obtain the true stress distribution with depth before the layers were removed. Formulas to evaluate corrections for stress have been derived. Two examples demonstrate that power series with few terms can provide us with an approximation good enough for the measured stress curve, and that the influence of the approximation on the corrective result is far less than that of the errors arising from the X-ray stress determination itself.

关键词: x-ray stress determination;stress correction;approximation;power;series;single-side removal;double-side removal;shot peening

PREPARATION OF ULTRAFINE METAL PARTICLES BY COMBINED METHOD γ-RAY RADIATION—HYDROTHERMAL CRYSTALLIZATION

CHEN Zuyao CHEN Bo QIAN Yitai ZHANG Manwei YANG Li FAN Chenggao University of Science and Technology of China , Hefei , China

金属学报(英文版)

The γ-ray radiation technique combined with hydrothermal crystallization was firstly used to prepare ultrafine metallic particles of An,Cu and Au-Cu alloy.Particle size for Au in average is about 10 nm.The morphologies were observed by TEM.The nucleation mechanism of metal particles and their stability are discussed.

关键词: radiation chemistry , null , null , null , null

X-Ray and Neutron Diffraction Studies on Thermal Parameters of Thalous Bromide

J.Bashir , R.T.A.Khan , T.Ikeda , Kenichi Ohshima

材料科学技术（英文）

Thermal parameters of TlBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order reflections, it was not possible to determine the individual thermal parameters. The X-ray diffraction measurements yielded B Tl=0.296(5) nm2 and BBr=0.162(5) nm2. The overall isotropic value, B was 0.252(7) nm2 which is in good agreement with B=0.230(8) nm2 obtained from present neutron diffraction measurements. The present values are also in good agreement with theoretical estimates obtained from the shell models.

关键词: Thallium bromide , null , null , null

Structural characterization of nanocrystalline copper by means of x-ray diffraction

Journal of Applied Physics

Quantitative x-ray-diffraction measurements were performed on a nanocrystalline Cu sample made by severe plastic deformation. The shape of Bragg reflections was found to be represented primarily by a Lorentzian function. A difference of as much as 6%+/-3% was revealed between the integrated intensities from the nanocrystalline and a reference coarse-grained Cu samples. The broadening of Bragg reflections from the nanocrystalline Cu sample was mainly induced by small crystallite sizes and microstrains inside the grains and/or the deformed layers near the grain boundaries. It was found that the grain sizes of nanocrystalline Cu in different crystallographic orientations are essentially the same, while the microstrains exhibit a significant anisotropy. The Debye-Waller parameter B of the nanocrystalline Cu sample was 0.97+/-0.06 Angstrom(2), which suggests that the atomic displacement from their ideal lattice positions equals on average 0.111+/-0.004 Angstrom or 4.3% of the nearest-neighbor spacing. (C) 1996 American Institute of Physics.

关键词: pd

聚碳硅烷纤维γ-ray辐射交联的研究

楚增勇 , 宋永才 , 许云书 , 傅依备

宇航材料工艺 doi:10.3969/j.issn.1007-2330.1999.06.008

研究了聚碳硅烷(PCS)纤维γ-ray辐射交联的不熔化效果,利用IR、TG分析了交联机理.结果表明,PCS纤维在空气、N2、He气氛下辐射13.8 MGy时均已实现不熔化,三者中以空气气氛下交联程度最高,N2、He气氛下辐照的PCS纤维的氧含量较低.在N2、He气氛下,Si-H及部分Si-CH3辐照产生自由基交联,形成了Si-CH2-Si的桥联结构;而在空气气氛下,氧参与交联还形成了Si-O-Si的桥连结构.

关键词: 聚碳硅烷纤维 , γ-ray , 辐射交联 , 不熔化

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

ZHAO Han GONG Yansheng SHEN Jingyuan RUAN Qikuan JIN Jialing ZHU Hanyu Research Institute of Qiqihar Steel Works , Fulaerji , China

金属学报(英文版)

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus.The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

关键词: X-ray diffraction , null , null

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

ZHAO Han GONG Yansheng SHEN Jingyuan RUAN Qikuan JIN Jialing ZHU Hanyu Research Institute of Qiqihar Steel Works , Fulaerji , China GONG Yansheng Senior Engineer , Research Institute of Qiqihar Steel Works , Filaerji 161041 , China

金属学报(英文版)

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus,The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

关键词: X-ray diffraction , null , null