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Introduction Processing through the application of severe plastic deformation leads to very significant grain refinement in bulk solids [1].
For example, tests on an Al-5% Fe alloy gave grain sizes of ~300 nm in ECAP and ~100 nm in HPT [5] and an investigation of highpurity Ni gave grain sizes of ~350 nm in ECAP and ~170 nm in HPT [6].
Prior to testing, the disks were annealed for 1 h at 773 K to give an initial grain size of ~1 mm.
Thus, the shear strain is 2πNr/h where N is the total number of rotations and r and h are the disk radius and height, respectively.
A similar set of datum points is shown in Fig. 3 for the HP Al, where results are presented for (a) different numbers of turns at a pressure of 1.25 GPa, (b) different numbers of turns at a pressure of 6.0 GPa and (c) for a total of 5 turns using different levels of applied pressure [9].

Judging from the structure of China's current agricultural trade, the scale of China's grain trade has been increasing since joining WTO.
And China's grain trade is affected by international trade environment.[8] Guiliang Tian: Virtual Water Trade Theory (China Water Power Press, China 2010) In Chinese. 8] The soybean imports are more than 80% of the total annual import and corn accounted for about 70% of export.
The major grain producing areas include Henan, Anhui, Shandong, Jiangxi, Hunan, Hubei, and Hebei.
Let’s examine the matter from the angle of virtual water, the country import a large number of food corps with high virtual water content (such as soybean), and export a great quantity of food corps with lower virtual water content (such as corn).
Therefore, each region of China should adjust its layout of the food production in order to give full play to the comparative advantage of China’s grain product, avoid planting disadvantage of the food products with high water consumption, and optimize the structure of grain industry.

Increase of ageing time reduces the number of nano/micro-twins, but they can be observed in all aged materials in spite of different strain rates.
The grain size is about 72 mm.
Grain structure (transversal direction) from EBSD mapping, (b).
The EBSD technique was used to analyze the grain or twin structure.
EBSD image, grain structure near the crack front, black line: grain boundary (GB); red line, low angle grain boundary<10° (LGB), pink line: twin boundary (TB).

Researches have indicated that damping behaviour of Mg varies with large number of factors, such as solute element, grain size and its distribution, grain boundary condition, texture, and et al.
It can be found that great numbers of basal planes are parallel to the loading direction in 0º specimen which leads to a hard orientation in the tensile specimen.
The preferred orientation should play an important role in the damping behaviour since these three types of specimen have the same grain size and grain boundary condition under room temperature.
The preferred orientation effect of grains at elevated temperatures could be softened.
The temperature effect should exceed the effect from preferred grain orientation.

Synchrotron radiation, with the benefits of a high ratio of signal to noise and high intensity, has been employed in a number of studies.
As Ce and Si introduced into TiO2, the peak of Eg(1) shifts to a low wave number, which indicates that the grains become smaller.
It indicated that Si doping could seriously affect the grain size of TiO2 nanoparticles, after Si doping, the grain size of TiO2 nanoparticles decrease obviously.
However, Ce doping has nearly no effect on grain size.
The Raman results indicate that the grains of CexSi0.10/TiO2 nanoparticles become smaller.

Owing to the chemically aggressive nature of hydrofluoric acid, a number of requirements are imposed on the protective coating: 1.
The influence of substrate surface roughness to the number of pinholes was studied in [14].
It should be noted that the formation of molybdenum columnar grains promotes efficient diffusion of hydrofluoric acid to the glass surface along the grain boundaries, extending continuously over the entire thickness of the film.
Fig. 2 shows the geometry of the system with parallel grain boundaries.
The geometry of the system with parallel grain boundaries.

Often a bimodal size distribution can be observed of large randomly situated ferrite grains in a matrix for very fine complex shaped grains.
In this case 60 grains has been assigned with an extra weight
This is especially the case with higher number of cells.
This enables an accurate applying of grain boundary properties.
Every Fourier point gets the grain (or cell) id of the grain where it is located in.

The average grain size of a sintered body was measured over 200 grains by the linear intercept method to compare with Scherrer formula’s results.
This results in better grain smoothing and magnetic isolation of the grains, giving rise to higher coercivities.
The average grain size of a sintered body was measured over 200 grains by the linear intercept method.
The average grain size was shown in Figure 3.
This layer at the boundary would result in reducing the number of sites available for the formation of reverse domains and then this would provide better magnetic isolation of the grains.

Also, higher upset length was reported for the toughness deteriorations in steels, that contain large number of inclusions that tend to arrange itself parallel to the weld interface, due to the metal flow [1].
The impurity atoms (P, S) tend to migrate to the grain boundaries.
The finer the grain size is, the greater the total grain boundary surface will be, and the impurity atoms will be more diluted.
There is a significant grain boundary effect on the macroscopic strength of the tempered martensite matrix, a strengthening mechanisms occurs based on the carbide precipitation at the grain boundary [8].
Another inconvenient are the impurities segregation at the grain boundary.

The dimensions of the particles, the number and composition of the liquid phrase as well as the number and the morphology of the pores will be directly affected by sintering temperature; then the properties of the ceramic proppant will be influenced by those above comprehensive factors.
With the holding time prolonged, new solid phase separated and grain boundaries formed, original particles grew gradually, the uniformity of the microstructure in the sample was affected to a certain extent, so the bulk density of the samples decreased gradually, the strength decreased slightly.
It can be observed in Fig. 2 that there were lots of alumina crystal grains and a few mullite crystal grains of rod like structures; the grains were filled among the glass phase, and all the grains were covered by the glass phase; in addition the interconnected pores can be observed inside the samples.
The mullite contained in the products was not much due to the high temperature required for its formation; the glass phase was produced by the reaction between the Fe2O3, MnO2, TiO2, alkali metal, alkaline earth etc. and Al2O3, SiO2, by which the crystal grains were bonded firmly [4,6]. 3.
The main crystal phase of ceramic were alumina, mullite and little aluminum titanate; the grains were filled by the glass phase. 3.