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There are a number of models available for the description of hysteresis loops of soft magnetic materials [6–8].
On the other hand, the models should have a limited number of degrees of freedom (parameters).
Its features have been thoroughly described in a number of useful publications, cf. e.g. [30, 31].
Another problem to be addressed in a forthcoming research is the attempt to correlate the values of model parameters with physical features of the material, e.g. statistical distribution of grain diameters, shape of grains etc.
Sablik, Modelling the effect of grain size and dislocation density on hysteretic magnetic properties in steels, J.

The backscattered image is according to the atomic number and the content.
The bright an area is, the bigger the atomic number is and the higher its content.
The atomic numbers of Fe and W are 26 and 74 respectively, and the difference is noticeable.
And it can be conjectured that WC with small size evenly dispersed in the grains.
Thus the grain of WC could grow on the crystal faces of (110), (20) and (20) in two-dimension way.

By calculating 3D properties like number of pixels and geometric 2D properties like circularity and perimeter for each of these shapes, they can be categorized into a group of precipitates and a group of shapes being in the foreground because of image effects like the curtaining effect.
It has to be mentioned that the recombination active defects of the first two groups are located within a grain and not at a grain boundary.
(C) Recombination active grain boundaries.
Similar transition metal precipitate distributions at grain boundaries compared to defects of group (B) are only found if deep etch pits along the grain boundaries indicate highly disordered areas.
Weber, Metal precipitation at grain boundaries in silicon: dependence on grain boundary character and dislocation decoration, Appl.

Average number density of particles (N) was calculated taking into account the number of particles of Ω phase precipitated on two {111}α planes and finally multiplied by 1.5 and divided by the area of the view area and foil thickness, which was measured by the convergent electron beam diffraction (CBED) method described in work [11].The errors associated with measurements of the diameter and thickness of Ω plates are listed based on the particle size distributions.
The microstructure of the solution treated alloy consisted of initial grains having average dimensions of ∼48 and ∼30 μm in the longitudinal and transverse directions, respectively.
Coarse particles of the primary θ-phase and ternary W-phase (Al8-xCu4+xSc) were situated on grain boundaries [10].
It is worth noting that the coherent particles of the Al3(Sc,Zr) phase having average size of ~25 nm were non-uniformly distributed within interiors of grains [10].
Values of the length (D), thickness (h) and number density (N) of the Ω particles within grain interiors are listed in Table 2.

This session is also held as the 4th symposium in succession to the serial symposia on "Ultrafine Grained and Nanostructured Materials", held in Nanjing in 2002, 2004 and 2007.
This reflects the large domestic research team on topic of "Ultrafine Grained and Nanostructured Materials". 35 papers was included in the present Proceedings.
Today, together with the growth of international community, we are witnessing the steady growth in fundings, research team numbers, as well as publications in this area in China.

On the other hand, tin (iv) chloride pentahydrate deposition showed a huge number of small particles that deposited on the glass substrate.
Larger grains size makes SnCl2 thicker than SnCl4.
Grain size and thickness directly affects to the electron mobility due to the variation of no of grain boundaries with the grain size of FTO film.
The grain size and its distribution are very important in a FTO fim since they affect not only to the sheet resistance but also transmittance [11].
Although the transmittance for SnCl2 higher than SnCl4 , it may be caused by the uneven distribution of grains on the soda lime glass.

In addition, the highly conductive Ag particles at the grain boundaries of the Ca3Co4O9 ceramics can form good electric connection and increase σ effectively[16].
This reveales that Ag particles are dispersed as the second phase at the Ca3Co4O9 grains boundaries.
The number of agglomerated Ag particles increases with an increasing Ag content.
The dispersed Ag particles contribute to the good connection between cobaltite grains, which reduces effectively the carrier scattering at the grain boundary. σ increases significantly over the whole temperature range with Ag content increasing and reaches a maximum σ of 126.39S·cm−1 for CGCO-0.2Ag at 700 o C, which is 23% larger than that of CGCO without Ag, and 10% larger than that of the undoped Ca3Co4O9 sample.
However, for all Ag added composite samples, the S value of the composites decreases with further increase of Ag content , which can be explained by the following reasons: the Ag particles with small grain size are well dispersed at the Ca3Co4O9 crystal boundaries, where Ag particles act as electrical connections between cobaltite grains, which has little influence on S[18].

Recently, nanocrystalline alloys containing tungsten as an alloying element for grain size control were developed [4].
Mild steel (3x3cm2) was mechanically pre-treated by sand paper with different grain size to reach homogenous bright surface.
Ni-W alloy labelled Ni-7W contains tungsten content 7 at. % and grain size reaches 16 nm in average (7W_16nm).
The average grain size of 16 nm was calculated using TOPAS software and the prevailing crystalline phase was found in this type of alloy.
The higher tungsten content in the alloys, the number of electroactive sites and corrosion rate growing due to amorphous character of the alloy.

Table 1 shows the calculated average crystalline grain size of β-MgH2.
For the mixture Mg + 2.5 mol% MgF2 + 5 mol% Fe, the average grain size reaches a critical value about 10 nm after 12h and then become steady.
For the complex hydride, the grain size calculated is around 10nm for the mixtures milled for 12, 24 and 48h.
Table 1. β-MgH2 grain sizes for the compositions Mg + 2.5 mol% MgF2 + 5 mol% Fe and Mg + 5 mol% FeF3 for different milling times.
In addition to the known effects of Fe acting as catalyst and the grain size reduction in lowering the temperatures of H-desorption, the number of transformation stages can be associated to the decomposition of a second hydride phase during heating.

The ELID grinding technology, using the electrolytic in-process dressing to make micron order, submicron order and even nano-scale superfine fine-grained grinding wheel maintain good machinability in the grinding process.
Giving full play to the cutting trace of the stability of the ultra fine-grained grinding wheel, with high efficiency, high accuracy, good surface quality, simple processing equipment and wide adaptability of processing materials[1].
Because in a certain range, with the increases of grinding wheel rotation speed, an increase is in the number of abrasive grains of the grinding area per unit time through, cutting thickness of each grinding grain un-deformed decreases, which result in declining in the cutting force of the single particle, less scratches left on the surface and the trace left by a grinding grain density increases when grinding.
According to the indentation fracture mechanics theory, this will cause brittle fracture of the SiC particles and remove and bring down the surface quality, which result in increasing surface roughness; on the other hand, the increase the feed speed makes the abrasive grinding force increase, scratches when grinding on the surface left increase and reduce the trace density left by a grinding grain, thus the surface roughness increased.