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Science direct.2:190–196.(2003)
Journal of Applied Polymer Science, 58: 209-230(1995)
Science direct.4:156–160.(2002)
Encylopedia of Polymer Science and Engineering.730(1989)
Oil & Gas Journal 95 (3): 70–72.(1997)

A Brief Analysis of Global Rare Earth Trade Structure Ying Li1,a,Anjian Wang2,b, Jianwu Li3,c*, Qishen Chen4,d 1Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China 2Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China 3Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China 4Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China aliyinghzy@sina.com, bajwang@cags.ac.cn, c jwli67@126.comdchenqishen2012@126.com Keywords: rare earth, trade structure, rare earth prices Abstract Since a large number of cheap rare earth from China entered the international market in the late 1980s, the rare earth structure in world started to change, and China replaced the United States as the largest rare earth producer and exporter.
However, it is concerned that the trade structure that China exports the cheap raw materials and buys finished goods back at a higher price is still continue to exist, for the reason that rare earth researches in China mainly focus on rare earth separation, extraction, as well as applied researches on traditional fields [2].
Statistics show that most of Japan’s exports of primary rare earth products (not including materials, components and products containing rare earth) were sold at a higher average price than imports, with higher added value after further processing (Figure 4).
China’s technology advantages are mainly in the front process of rare earth industry chains such as mining, smelting separation and production of some materials, and China still export primary mineral products to other countries.
Japan and the United States have a considerable advantage in manufacturing rare earth materials, components and final products, and the additional value of rare earth products in these countries is much higher than that in China.

Material and Method Test Material.
In addition to the differences on protein content, there are also differences on wheat grain shape, grain color, grain weight and many other characteristics between these materials.
These materials have better differentiation and representation.
Chinese Agricultural Science Bulletin. 22 (2006) 366-371
Journal Infrared Millim.

The laser micromachining is the process that omits small energy pulse laser beam on the surface of the workpiece and removes the material from the surface.
Because of the thermal process of the laser, the material melts and vaporizes away.
Then, it forms a crater on the surface around spatter of melting material, as shown in Fig.1.
Changsha Telecommunications Technology College Journal, 2010.9 (3): 22-25
[5] M.Kiyak,Q.Cakir.Examination of machining parameters on surface roughness in EDM of tool steel.Journal of Materials Processing Technology.2007,191(1-3):141-144P.

Fused materials and bond quality are also the main elements of the factors affecting the quality of clothes.
Conclusions In this paper, we present the principal component analysis .In general, the bond quality is closely related to the material properties under the correct pressing condition.
Acknowledgement Thanks for the the aid financially help of the Development Funds Project About the Humanities and Social Sciences of Shandong University of Technology.
[2] Jeong, S.H., and Barker, R.L., Journal of Korea Fiber Society., 33(1996),p. 83

Such treatment measures, not only obviates the manual handing process, and also achieve automatic air temperature control through the preferred PID algorithm and set of different heating curve, according to different material types of mold sand.
Analysis of experiment result The actual drying process of large scale mold sand is carried out under relatively open environment, and needs to preset heating curve different according to different materials with better consistency.
Acknowledgement In this paper, the research was sponsored by the Natural Science Foundation of Zhejiang University of Technology (Project No. 2012XZ013).
Journal of Inner Mongolia University(Acta Scientiarum Naturalium), 1997-28(6):838-841.

Determation of material performance.The material performance datas needed during fatigue assessment are the coefficents and in Eq.1,also the threshold stress intensity factor .These coefficents can be got through special fatigue crack propagation rate test.According to the test data, using the least squares regression,we can get and .
Fatigue assessment program develop and verify of surface defects According to the surface defect assessment methods provided in the previous chapter, a special program is developed with Fortran language.The program can be used to calculate the fatigue crack propagation and assess the lifetime.Once the material properties , the range of stress and the initial size of defect are known,the initial amplitude of stress intensity factor can be calculated through this program, then we can determine that whether the fatigue asseement should be necessary.As to the defect need be assessed, if the fatigue cycle number is known,the final size of the defect can be calculated after the cycle,then the safty assessment can be conducted.Besides,if without the fatigue cycle life information, we can set the crack deepth,length or amplitude of stress intensity factor be assessment parameters,thus providing reasonable technical data for the determination of repair cycle.
Guedes Soares, Fatigue damage assessment of corroded oil tanker details based on global and local stress approaches,International Journal of Fatigue 43 (2012) 197-206
(In Chinese) [6] Shun Diao, Yaorong Feng, Zhuangchuan Jing, Study on the fatigue properties of oil gas pipelines and its prediction of service life, Chinese safety science, 18 (2008) 123-130.

Low-temperature cracking analysis of asphalt pavement LI Zhaoshenga, TAN Yiqiub School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, P.R.China alizhaoshenghit@163.com, byiqiutan@163.com Keywords: asphalt pavement; low-temperature performance; temperature shrinkage coefficient Abstract: Establish the mechanical model of asphalt pavement low-temperature cracking, analysis the factors leading to cracking.
The main factor of resistance to low-temperature shrinkage cracking refers to unit area cracking energy accumulated along the thickness direction of asphalt surface layer: In the formula: --tensile strength of asphalt mixture in the temperature of Ti; --limit tensile deformability of asphalt mixture in the temperature of Ti; h--thickness of asphalt layer; Formula shows that: ability of resistance to low-temperature cracking is not only related to factors of material (tensile strength and limit tensile deformability of asphalt mixture) but also related to the asphalt layer thickness h and its structure factors such as combination.
The deposited energy that leads to shrinkage cracking is represented as: In the formula: аi:Temperature shrinkage coefficient of asphalt mixture; B,L:Respectively represent the width of the pavement and crack spacing; σ(T0，hi):temperature stress at hi thickness of asphalt pavement ; ΔT(T0，hi):difference in temperature leading to temperature stress Formula shows that: the factors that lead to crack are not only related to factors of materials such as temperature shrinkage coefficient of asphalt mixture and temperature stress but also related to other factors such as structure combination and temperature distribution.
[5] J.T.Christison,The Response of Asphalt Concrete Pavements to Low Temperature climatic Enviroments,Proceedings of 3rd Int.Conf.on the Structural Design of Asphalt Pavements,Vol.1,1972 [6] C.Vander Poel,A.General System Denscribing the Vicoelastic Properties of Bitumen and Its Relation to routine Test Data Journal of Applied Chemistry, Vol.4,1954,P221~236 [7] B.

Liu c Department of Mechanical Engineering, Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084, China a liuzy02@mails.tsinghua.edu.cn, b scjxqy@tsinghua.edu.cn, c liubc@tsinghua.edu.cn Keywords: microstructure simulation, AZ91D alloy, die casting, cellular automation method Abstract.
Simulation Results and Experiment Validation Experimental Material and Method.
Fig.2: Specimen positions on the cylinder cover casting overflow and exhaust channel casting runner P3 P2 P1 Experimental grain structure solute concentration Fig.3: Comparison of the experimental micrographs and modeling results for the positions P1~P3 Table 2: Grain size and eutectic percent Average grain size [µm] Eutectic percent [%] Position Experiment Simulation Experiment Simulation P1 30.1 31.8 9.6 10.3 P2 13.2 14.7 10.2 11.3 P3 8.2 9.1 10.8 11.7 Acknowledgements The research was sponsored by National Basic Research Program of China (2005CB724105) and National Natural Science Foundation of China (10477010).
References [1] Beltran-Sanchez L, Stefanescu D M: Metall and Mater Trans 35A(2004), p. 2471 [2] Thuinet L, Lee P: Modeling of Casting, Welding and Advanced Solidification Processes - XI(2006), p. 457 [3] Wang Y S, Zhang Y B, Wang Q D etc: Acta Matall Sin 38(2002), p. 539 [4] Thévoz Ph., Desbiolles J.L., Rappaz M: Metall Trans 20A(1989), p. 311 [5] Kurz W., Giovanola B., Trivedi R: Acta Metall 34(1986), p. 823 [6] Feng W M, Xu Q Y, Liu B C: Journal of Tsinghua University 43(2003), p. 605 [7] Xu Qingyan, Feng Weiming and Liu Baicheng: J Mater Sci Technol 19(2003), p. 391 [8] Steinbach I, Beckermann C, Kauerauf B, Li Q, Guo J: Acta Materialia 47(1999), p. 971 [9] Li Q, Beckermann C: Physical Review E 57(1998), p. 3176 (c1) (a1) (b3) (c3) (b2) (c2 ) (b1 (a3 ) a2 P1 P2 P3

As advanced material, which is high-strength, it is the favor object of lots of researchers.
So the equation 3-1 and 3-1’ can be writeen as follows: (3-2) (3-2’) is the effective bonding coefficient between binding material and FRP bars (0.5<<1).
Assume that , and , are respectively shear elasticity and shear strain, , and , are lateral displacement and longitudinal displacement, suppose the stress-strain relation of the binding material and geometrical relationship are linear, that is: (3-3) Because all of factor of the FRP bars are same, so ==；；,and we can get that: (3-4) (3-5) (3-6) Simultaneous equations 3-4,3-5 and 3-6, Equation on both sides derivation of x, (3-7) Because of the thickness of binder is very little, so we can show like t his (3-8) In the equation is thickness of binder, and and are longitudinal strain along flank of FRP bars and concrete.so equation 3-8 can be writeen like this: (3-8’) And in the eqution, and are strain of FRP bars and concrete, and are modulus of elasticity of FRP bars and
From:Science and technology department of hebei province
Journal of South China University of Technology, 2002,30(11):101-105