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Because the absorption of SO42- prevented the anisotropic growth of grains to a certain degree and therefore isotropic growth occurred.
Moreover, this absorption also inhibited the abnormal growth of the grains.
It can be seen that under such circumstance, the ZrO2 composite ceramic acquired by using the combination method displayed smaller grains.
Consequently, the stability of t-ZrO2 is weakened as the number of ions in metastable state increases.

He also identified in such conditions some fine-grain structures, which can improve a uniform-elongation of the nugget.
Table 2: Welding parameters and the nuggets diameters Sample number Current value, [kA] Force value, [kN] Time per welding (soft cycle), [s] Holding time [s] Nugget diameter (Dn), [mm] 1 5 4 0.7 2 5.1 2 5.1 3 4.9 4 4.8 5 4.9 6 5.0 7 4.9 8 4.9 9 5.0 10 4.9 Figure 4: Image of the mark obtained by means of the AFFRI equipment (magnification: 10x) In order to determine the micro hardness of the welded parts, it was necessary to obtain flat surfaces; the test samples were sectioned along the axis of the welded nugget using a disc tool and adequate cutting equipment.
Subsequently, the resulted surfaces were finished by abrasion using silicon carbide with low grain sizes.
Analysing the hardness map, it can say that sometimes there are large gaps between measured values of distinct interest areas which could be caused by inhomogeneity and changes in the grain size of the materials in the newly formed structures.

Nie et.al found that Er in alloy can play an important role like that of Sc and Zr, which could optimize grain structure, and improve comprehensive mechanical properties, thermal stability and weldability.
We also predict that interaction energy of Al-Er is much negative under the same temperature, which showed that bonding ability and interaction of Al and Er is stronger, and they have a great tendency to combine in alloy solution, the composition super-cooling in the interface occurred easily during the solidification, naturally prone to segregate, even though the concentration of Er is small, the Al3Er phase precipitate preferential at interface, which act as the center of heterogeneity nucleus, naturally remarkable refine grain size.
Conclusion 1)Er concentration in Al-Er alloy shows a negative deviation from Rault's Law at 1073K, deviation degree is larger at the low concentration range, therefore real concentration is low, mainly due to Er atoms are prone to segregate at interface or dislocation; 2)The interaction parameters between Al and Er is LAl-Er=-204.29exp(-T/2000) kJ/mol, which shows the bonding ability and interaction energy between Al and Er are strong, and Al and Er have a great tendency to combine in alloy solution, the composition super-cooling in the interface occurs easily during the solidification, intensively refine grain size; 3)The minimum of mixing enthalpy, excess Gibbs energy and excess entropy are -38.5 kJ /mol, -27.6kJ/mol, -10.5J/mol respectively in the whole concentration range, which indicate that properties of alloy solution are stable.
Acknowledgement The authors thank the financial supports of the State Key Foundamental Research Project of China with the contract number (2005CB 623706) and China National Outstanding Youth Plan (50525413) and Beijing Education Plan (KM200710005011 and 000855).

The tests conducted on specimens and the numbers and dimensions of each kind of specimens produced in this study are different with each other.
Obviously, the size and shape of IOT grains are smaller and more irregular respectively than those of NS ones.
Comparing to mortars with NS as fine aggregate, those with IOT as fine aggregate, the size and shape of IOT grains are both finer and more irregular respectively. 2.
In summary, comparing to reference sand, as fine aggregate, iron ore tailings can enhance compressive strength related to its finer and more irregular grain shape and the ability on complicating porous structure in mortars.

The results of plasma nitrocarburizing at 570 °C showed the highest surface hardness, highest wear resistance and lowest coefficient of friction due to the number of phases ε.
The α-Ti phase had equiaxed grain.
The grain structure (spectrum 1) on the surface contains 27.39% titanium atoms, 45.42% nitrogen atoms and 27.19% carbon atoms.
The grain structure at cp titanium surface has a higher nitrogen and carbon content than dark areas and light areas.

Therefore, recently improved efficiency of TiO2 based photocatalysts is associated with the synthesis of the anatase crystalline particles containing a greater number of unstable faces (001) [5-6], or thermodynamically less stable TiO2 modifications, such as brookite [6-7].
Thus, having been heated to 300°С in vacuum and in air, TiO2 film structure can be represented as an amorphous matrix with separate anatase crystal grains.
Temperature increase to 400°С leads to increase of existing anatase crystal grains and formation of new rutile crystal grains in TiO2 films, but does not transform it into crystalline state.

Materials and Methods Bacterial Strain and Culture Media The microorganism used throughout the study was Sporosarcina pasteurii (strain number 11859 provided by American Type Culture Collection(ATCC)).The diameter of rotundity spore is about 0.5~1.5μm.
However, samples subjected to bacterially induced mineralization showed much less damage, and the newly formed carbonate grains were not removed in detectable amounts.
However, samples subjected to bacterially induced mineralization showed much less damage, and the deposit grains were not removed in detectable amounts(Fig. 5, Fig. 6).
SEM observations and weight loss measurements of sonicated samples demonstrate the strong adhesion between the samples and the deposit grains, as well as the positive consolidating and/or protecting effect of the biodeposition. 0 5 10 15 20 25 30 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 a △Wt / % Time / min culture sonicated control sonicated uninoculation sonicated fresh sonicated culture non-sonicated control non-sonicated fresh non-sonicated 0 5 10 15 20 25 30 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 b △Wt / % Time / min culture sonicated control sonicated uninoculation sonicated fresh sonicated culture non-sonicated control non-sonicated fresh non-sonicated (a) Concrete (Urea-CaCl2) (b) Marble (Urea-CaCl2) Figure 8: Mass loss (△W) vs ultrasonication time of samples Conclusionss Bacterially induced mineralization

The transparent powder grains were found to become translucent at the phase transition as had previously been observed.[9,10] It is clear that pressure induced changes to the diffraction pattern of walnut GeO2 were observed above 8.99 GPa.
It is worthymetioned that the high pressure behavior of GeO2 bulk materials remains under controversy. [9-11] Itie et al, [11] reported a transition occurred above 6 GPa at which the germanium coordination number increases from four to six by EXAFS.
As the nano-crystalline b-GeO2 sample are of an average grain size of 20nm.
As a result, the high pressure phase transition of b-GeO2 to monoclinic phase may occur on the grain boundary of these nano particles. [18b] but further studies are still needed.

Introduction The prolonged life-expectancy leads to an increasing number of people that require the replacements of degenerated or damaged tissues by artificial materials.
In all studied cold swaged (with minimal section reduction 75%) and solution treated specimens the microstructure consists of equiaxed β-grains (see Fig. 6).
During aging treatment (450°C/8h/water quenched) of cold swaged (section reduction 90%) specimen with the lowest oxygen content fine needle-like α-particles precipitated in grain interiors.
There can be also observed coarser precipitates on grain boundaries, which can be also distinguished in light micrographs (Fig. 7a,b).

Standard k-ε turbulence model of turbulent kinetic energy equation (3) Standard k-ε turbulence model dissipation rate equation (4) In (3) and (4), k-turbulence kinetic energy; μt is turbulent viscosity, Pa/s; σk, σε is turbulent Schmidt number of the k equation and ε equation; C1ε is turbulent kinetic energy of the shear rate multipliers; C2ε is turbulent kinetic energy dissipation of the multiplier; Cμ is turbulent viscosity correction factor; the C3 is k-ε buoyancy model coefficients; C4 is k-ε buoyancy multiplier; β is coefficient of thermal expansion; σt is empirical parameters; T is Temperature, k; Ф is viscous heat generated items.
(5) Where, Hcmax is vacuum maximum value of the vacuum chamber, kPa; d is suction hole diameter of the seed plate, cm; C is distance between the center of seed gravity and the suction seed plate, cm; m is one seed quality, kg; v is line speed at the center of the suction hole on the row seed plate, m/s; r is turning radius at the suction hole of the row seed plate, m; g is acceleration due to gravity, m/s2; λ is seed frictional resistance combined factor, λ=(6 to 10) tan θ, θ is natural angle of repose of the seed; K1 is coefficient of reliability of the absorption seed, taking 1.8 to 2.0, thousand grain weight of the seed are small and shape spherical, taking a small value; K2 is outsidecondition factor, taking 1.6 to 2.0, it take greater when the seed grain weight is large.
The test used the seed plate with diameter of 180 mm and thickness of 2 mm, according to the literature[14], the suction hole diameter selected 4.2 mm for small grain corn. 1. rack 2.exciter 3. sediment device 4. pulley 5. sandbox 6. triangle bracket 7. seed containers 8. air-suction seed metering device 9. the inverter 10. conveyor belt 11. fan 12. exciter control panel Fig.5 The simulated surface air-suction seed metering test-bed Experimental analysis of rowing performance of different distribution diameter of suction hole.