Search results

It is the carrier and the material and energy providers of the all the region life organisms to suivive and develop.
Chinese Journal of Applied Ecology, 2002, 13(3): 354-35.
Journal of Environmental Management, 1995, 3(57): 21-29
Science, 1997, 277:515-524
Journal of Tsinghua University(Science and Technology), 2010, 50(6): 913-916.

Generation of void-like structures during hot-hydrogen etching of Si substrates for 3C-SiC epitaxy P.Hens1,a, J.Müller2, L.Fahlbusch1, E.Spiecker2, P.Wellmann1 1 Department of Materials Science, University of Erlangen-Nuremberg, Germany 2 Center for Nanoanalysis and Electron Microscopy (CENEM), University of Erlangen-Nuremberg, Germany aphilip.hens@ww.uni-erlangen.de Keywords: 3C-SiC, heteroepitaxy, silicon, cleaning, voids Abstract.
Fig.1: Plan view SEM image of an irregular shaped void of type II within the 3C-SiC seed layer Experimental Standard silicon (100) wafer material was used as substrate for the epitaxial growth.
As pure silicon does not evaporate under conditions applied during hydrogen etching, a kind of catalyst for evaporation or diffusion of material is needed to form the voids of type II.
Sundgren, Journal of Crystal Growth Vol. 182 (1997), pp. 379-388 [2] B.
Stoldt, Carlo Carraro, Roya Maboudian, Diamond & Related Materials, Vol. 16 (2007), pp. 74–80 [4] K.

Orientation relationship between Fe2M and martensite in M50NiL steel Lou yanzhi Beijing Institute of Aeronautical Materials, Beijing 100095, China louyanzhi@sina.com Keywords: M50NiL steel; Fe2M; orientation relationship Abstract: In this paper, high resolution electron microscopy (HREM) was used to observe nano-sized Fe2M precipitates in M50NiL steel, and crystal structure of which was also investigated by selected area electron diffraction(SAED).
M50NiL steel is ideal material for high temperature aerospace structural parts[1-5].
Materials and Methods The experimental steel samples were taken from M50NiL bearing steel.
Journal of University of Science and Technology Beijing, Vol. 35(2013),p.201 [5] J.F.
Metallurgical and materials transactions A, Vol. 33(2002), p.1963 [7] C.Z.

“4M1E” Factors and Analytic Hierarchy Process (AHP) The influence factors mainly include five aspects: Man, Material, Machine, Method and Environment，referred to 4M1E factors[2].
Material factor: It directly influences the construction quality, especially for structural materials, so the material quality assurance is the premise of engineering quality.
Table 5 Judgment matrix of material factor B2 C4 C5 C6 Wi C4 1.0000 3.0000 0.2000 0.1782 C5 0.3333 1.0000 0.1111 0.0704 C6 5.0000 9.0000 1.0000 0.7514 Judgment matrix consistency ratio：0.0279＜0.1，meet the consistency；Weight of total goal：0.6377.
Communicating Design Quality Requirment for Public Sector Design, Journal of Management Engineering(2008) [2] Qi Chen: the Research of key Problems in Construction Quality Control, in:Architectural Technology and Applications(2006) [3] Maosheng Yang, Operational research .
Xi 'an: Shaanxi Science and Technology Press(2011)

Rietveld refinement of the BaTiO3 from X-ray powder diffraction Sun Feng1, a , Yin yansheng1,b 1 Institute of Material Science and Engineering; Ocean University of China; Qingdao 266003; China a kyoback@ouc.edu.cn, byys2003@ouc.edu.cn Keywords: Ferroelectric Ceramic; X-ray diffraction; Crystal structure Abstract.
The raw materials were C16H36O4Ti , Ba(OOCCH3)2, C2H5OH, CH3CO2H.
Grain size effect on ferroelectric phase transition in Pb1-xBaxTiO3 ceramics.J.Phys.Chem.Solid. 1998,59(6-7):1161~1167 [2] P.P.Phule,S.H.Risbud.Review-Low-temperature synthesis and processing of electronic materials in the BaO-TiO2 system [J].
Journal of Materials Seience,1990,25(2B):1169-1183

Basic Assumptions (1) a model materials for an ideal elastic-plastic;(2) the same of the component section remains when the lateral bending and twisting;(3) The side of the twist deformation is a very small ;(4) Component without defect.
Material Model The ANSYS takes ideal elastic-plastic model.
The Solving steps and methods of ANSYS (1) Selecting unit type, defined unit real constant and built the ideal model of unit elasto-plastic material
(2) Building finite element analysis model, attached geometry and material characteristics to the flange, webs and so on, divided unit grid, and built finite element model of wedge-shaped beam
Journal of Xi＇an University of Architecture & Technology, 1998 [2] Ping Ji.

The stress intensity factor analysis of crack tip in plastic zone Glass fiber reinforced plastic composite materials are used in a wind turbine blade in this paper, the classic fracture theory is not suitable for the crack-tip’s stress field of this kind of composite material.
Examples In the modeling, width of the flat is b = 0.2 m, the crack length is 2a, the material of the elastic modulus is Pa, and, the Poisson ratio is 0.29.
Acknowledgments The paper is supported by National Natural Science Foundation of China (50975180 and 51005159) and Foundation of Liaoning Educational Committee (L2010401).
[6] Nakagaki, M. and Atluri, S.N: Structures and Materials, Vol. 18 (1980) No.9, p.1110~1117
Pierre: Journal of Sound and Vibration, Vol.138 (1990), p.115~134.

Experimental Materials Calcium lignosulfonate purchased from Feihuang Chemical Company (Mw19605, Mn17774, ash16.3%), was used without further purification.
Other materials used were of technical grade.
Recent application of lignin: A sustainable alternative to nonrenewable materials.
Journal of Polymers and the Environment, 2002, 10, 39-48
Journal of Applied Polymer Science, 2002, 84, 468-472

It has been a hot research topic to develop structral materials with properties of lightweight, high strength, versatility, durability and sustainable development etc [1-5].
Anyway, it is very significant and necessary to deal with study on frost resistance of steel fiber reinforced lightweight aggregate concrete or promote its application in engineering, no matter from view of engineering and technical progress, materials science development or implementation of sustainable development strategy.
Zhao, Development and applications of concrete and its reinforcing materials, Journal of Building Materials, Vols. 3 1 (2000) 1-6
Yu, Factors affecting frost resistance of concrete and its prevention measures, Learned Journal of Taishan Township Enterprises University for Employees, 2 (2010) 47-48
Huo, Effect of silica fume and fibers on frost resistance durability of lightweight aggregate concrete, Journal of Wuhan University of Technology, 11 (2008) 65-68

Optimizing the Design Parameters of Spherical-cymbal Transducer Based on Comprehensive Point-rating Method Wu Shilin a, Zhang Qi b, and Xiong Jiulong c Department of Instrument Science and Technology, College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan, P.
When designing a spherical-cymbal transducer, nine different design parameters (refer to Fig. 1 and Fig. 2), including transducer diameter Dp, cavity depth h, cavity bottom diameter dc, PZT thickness tp, end-cap thickness te, epoxy thickness, PZT material, end-cap material, and epoxy material, should be considered.
Chinese Journal of Sensors and Actuators.
Journal of National University of Defense Technology.
Chinese Journal of Scientific Instrument.