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Carbonate can substitute at two sites in the apatite structure, namely the hydroxyl and the phosphate ion positions, giving A and B-type CHA, respectively.
Fig.3 SEM morphologies of HA reacted with SBF for different times (a) 6 days; (b) 12 days; (c) 18 days; (d) 24 days The distortion of crystal structure increases the solubility [15, 16], attributable to the carbonate substitution.
The disorderly structure of CHA increased the solubility, attributable to the carbonate substitution, thus more Ca 2+ and PO43- ions contained on the surface.
Kawashita: Bone Engineering( Canada: 2000) [12] Zhao Zhengguo:Colloid and interface chemistry (Chemical industry Press,Beijing: 2004) [13] Wang Hui, Gu Guo-Hua, Qiu Guan-zhou: J Cent South Univ T.
Vol. 5(2006), p.942-947 [14] Wu Ji-hua, Yang Zhao-xi, Zheng Zhong:Colloid and interface chemistry (South China Univ of Tech Press, Guangzhou: 1999) [15] R.Tang, Z.

From the theory of chemistry valency and bond, we can see that the longer bond-length is, the lower energy is needed for destroying the steady structure mentioned above.
So the chemistry bond between Sn 4+ ion and Fe 2+ transforms from steady structure (25 ℃) to sub-steady structure (100 ℃), that is, the bond is broken at 100 ℃ and electron hopping between Fe 3+ ion and Fe 2+ takes place.

MgO-Al2O3-SiO2 Glass-Ceramic Prepared by Sol-Gel Method Qiuhua Yuan1 , Peixin Zhang1a, Li Gao 1,Hailin Peng 1, Xiangzhong Ren 1, Dongyun Zhang2 1.School of Chemistry and Chemical Engineering, Shenzhen University , Shenzhen 518060, P.R.China 2.
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, P.R.
The powder was pressed to obtain the green body using a performing machine, and the green body was sintered to obtain the glass-ceramics at a certain temperature. 2.2 Testing of Structure and Performance DTA was performed with Netzsch STA409c at a scan arte of 10°C/min.
Results and discussion 3.1 Characteristics of gel powders Figure 1 shows the DTA curve of gel powder, it can be seen that the powder exhibited the change of its structure at 790 °C, and then the crystallization peak emerged obviously at about 897 °C and 1058 °C. 600 700 800 900 1000 1100 1200 897℃ 1058℃ 790℃ 图39 凝胶粉末的DSC曲线 Fig 1.
On the other hand, it has been established that most of the glass powders calcined at 700 °C reveal an unstable amorphous state by XRD analysis, it is easy for them to change the original disorder structure, and translate into the state of low-energy stable crystallinization by the mass transfer of proliferation, evaporation-condensation and nucleation growth, and promote the progress of sintering.

At ambient conditions magnetite, Fe23+Fe2+O4, adopts a cubic spinel structure (space group Fd3m) with the inverse configuration [Fe3+][Fe2++Fe3+]O4 , where A and B mean respectively the tetrahedral and the octahedral sites in the spinel structure, AB2O4. [7] It can clearly be seen that substance reacted with SiO2 is Fe2+ (FeO) from the FeO-SiO2-Fe phase diagram. [8] At room temperature, Fe2+ (FeO) exists in the form of Fe3O4 (FeO·Fe2O3).
(5) It could be speculated that the element Si gets into Fe3O4 and partially replaces Fe2+ because Fe3O4 and Fe2SiO4 have the same crystal structure.
[3] Chern, Tsann-Shyi and Tsai, Hsien-Lung:  Materials Chemistry and Physics (2007), Vol. 104, No. 2-3, p. 472-478
[4] Mai TA and Spowage AC: Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing (2004), Vol. 374, No.1-2, p. 224-233 [5] Chern, Tsann-Shyi and Tsai, Hsien-Lung: Materials Chemistry and physics (2007), Vol.104, No.2-3, p.472-478 [6] Zanchrtta.A, Lortholary.P and Lefort.P: Journal of Alloys and Compounds(1995), Vol. 228 , No.1, p.86-95  [7] Information on http://www.factsage.cn/ [8] Luo Dawei and Shen Zhuoshen: Journal of Alloys and Compounds(2009), Vol.477, No.1-2, p.407-413 [9] Sasaki S 1997 Acta Crystallogr.

To reduce interactions, the most sensitive material is usually sandwiched within a multilayer structure that modulates the effective diffusivity and the solubility to penetrants.
According to literature, two effects independent of polymer chemical structure are known to impart D in solids: tortuosity [13] and local distribution of free energies [12,14].
Relationships between heat of adsorption and molecular structure were used to derive the activity coefficient of the non-volatile diffusing solute: biphenyl.
Desobry: Industrial Engineering Chemistry Research 48 (2009), p. 5285
Desobry: Industrial Engineering Chemistry Research 10 (2010), p. 1021

The test results show that: Aluminum alloy 6063 bonding joints occur serrated yielding phenomenon in the tensile shear test; In a certain layer thickness range, tensile shear strength of aluminum alloy 6063 bonding joints correspondingly increases with the thickness of samples increasing; Different surface treatments on aluminum alloy 6063 have a great influence on tensile-shear strength, and mechanical polishing and skim can significantly improve tensile shear strength of aluminum alloy 6063 bonding joints. 0 Introduction Using lightweight materials is one of the primary methods of automobile lightweight structure.
Bonding method is simple operation, low cost, adopted by more and more[2] .The strength of adhesive joints is a primary evaluating factor for bonding structure , which is closely related to vehicle safety.
Different surface treatments can affect bonding properties because of the change on aluminum alloy surface cleanliness and roughness and surface chemical structure.
Chemistry and Adhesion, 2004( 6): 303- 333
[6]Jianfang Zhou, AnLi,Baolin Rao.The impact of Shear strength between the metal workpiece surface treatment and bonding process of bonding [J].Chemistry and Adhesion,2007 (29) :30-32

Cyclodextrins in Textile Finishing: Fixation and Analysis Attila Bereck University of Wuppertal, FB C/Textile Chemistry, Gauss-str.20, D-42097 Wuppertal bereck@uni-wuppertal.de Keywords: cyclodextrin, cyclodextrin analysis, textiles, permanent finish, formaldehyde release Abstract.
Therefore, cyclodextrins build host-guest complexes with molecules of suitable structure (form/size/polarity).
As compared to the samples treated with crosslinking agents alone (regardless of the chemical structure of the crosslinkers), Cavatex HP® reduced formaldehyde release in each case.
References [1] Szejtli, J., Osa, T., Comprehensive Supramolecular Chemistry,Vol.3, Cyclodextrins, Elsevier, (1996) (Pergamon) Elsevier, Oxford, N.Y., Tokyo, 1996 [2] W.
Riegel, J. of Molecular Structure, 744-747 877-880 (2005) [10] H.M.

Introduction Surface modification provides a large flexibility regarding materials with unique features through the manipulation of materials chemistry and structure as well as through the combination of base material properties with surface attributes.
One of the most important and applied techniques to modify the surface structure and chemistry is plasma technique.
Amorphous, "glassy" and dense structures were revealed for DLC-layers independent form the treatment of substrates.
Furthermore growth CrN structure was observed.

Zirconia exists as three different structures, the monoclinic phase is thermodynamically stable up to 1100℃, the tetragonal phase can exist in the temperature between 1100℃ and 2370℃, and the cubic phase is found above 2370℃.
Martensitic transformation will occur when ZrO2 changes from tetragonal to monoclinic structure, along with lattice expansion of about 7% in volume, which will cause cracks in materials.
In this article effect of stabilizer CaO on the phase structure of ZrO2 was mainly studied.
From Fig.4c, the phase structure of not doped ZrO2 powders are mainly monoclinic phase, while CaO stabilized ZrO2 powers tend to keep the cubic phase.
Materials Chemistry and Physics, 2010,120: 148-154

Improvement of Water Vapor Permeability of LLDPE/EVA Film with Zeolite A as Filler Suparat Rukchonlatee1, 2, a*, Nattarika Jaisomboon1, b, Tawan Sooknoi1, 3, c 1Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand 2Polymer Synthesis and Functional Materials Research Unit, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand 3Catalytic Chemistry Research Unit, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand asuparat.ru@kmitl.ac.th, bnat9nat@gmail.com, ckstawan@gmail.com Keywords: LLDPE, EVA, Zeolite, Water Vapor Permeability (WVP), Packaging film.
However, LLDPE packaging exhibits low water vapor permeability (WVP) due to a nonpolar nature and its semi-crystalline structure [2].
However, as EVA contains both polar component derived from the vinyl acetate group and a nonpolar chain structure similar to LLDPE, it can readily improve compatibility between the LLDPE and the zeolite A.
The marked increase in WVP of this film is not only derived from the presence of highly flexible and polar structure of EVA, but also a high loading (25%) of polar and porous structure of zeolite A.