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Researches suggest that mass transfer coefficient in RBHC is 10-1000 times of that in conventional devices[14].A large number of reported literatures[15-18] confirm that RBHC has been successfully applied in the preparation of ultrafine nano-powders via chemical precipitation method because of the higher efficiency micro-mixing and strengthener mass transfer.
It’s known that the higher peaks intensity presents, the higher crystallinity, larger grain size will.
Big crystal grains will reduce powder surface energy so that agglomeration phenomenon will be improved.
What’s more, the grain sizes of ZrO2 varying with different hydrothermal time calculated from the Scherrer’s formula are shown in Fig.6, with the increasing of hydrothermal crystallization time grain size increased significantly firstly,following by a slight increase.
As the extension of hydrothermal time, the equilibrium trends to crystalloid which is more stable than amorphous.Therefore, the crystal conversion rate raised , meanwhile grain growth becomes more fully along as the increasing of grain size.

Specimens were water quenched after the roughing step to determine the initial grain size (see results in Table 1).
Examples of the grain size maps obtained for some of the steels investigated are shown in Fig. 1.
Grain size maps of the initial microstructure obtained for some of the steels investigated.
In the bibliography, different values for the grain size exponent have been reported.
This was attributed to C segregation effects and/or to the formation of a larger number of C-Mn dipoles.

Grain safety is always the major global strategic issue related to national economic development, social harmony and stability, national security and self-reliance. 
The grain industry is also faced with severe challenges and good opportunities for development from the production, processing, circulation to consumption.
The safety of national grain is mainly measured by the safety coefficient for grain storage.
As the key equipment of access in the grain circulation link, granary plays an important role in grain safety, which is related to national security and calls for intensive construction.
With the help of these parameterized information, software based on BIM can automatically recognize different components in the model, and get statistics on the number of different components in the model, forming a database to facilitate later modifications.

However, the dimension and number of rosette-like grains were changed in accordance with the different processing parameters.
For example, when the films were preheated at 400°C with a heating rate of 20°C/min in electric furnace instead of hotplate (which was used to prepare most of the samples), the rosette-like grains could still be observed - their dimensions were significantly reduced whilst the number of rosette-like grains was increased (Fig. 3(b)).
Both the pore and the grain size are around 50nm.
The rosette density (the number of the rosettelike structures in a same area) increased with the increase of the lead excess.
At the same time, the grains grew up significantly at the expense of fine grains which were more soluble in the liquid phase[20, 21,22].

The dark grains, referred to as point (a), which is represent Al2O3 grains and show the existence of Al and O elements.
Al2O3 is the dark grains, while the light grains are YSZ.
The Al2O3 and YSZ grains are uniformly distributed.
However, abnormal growth, formed as platelet grains, occurs between ZrO2 grains; this is especially apparent in samples containing 0.7 wt.% of Nb2O5.
The existence of the Nb2Zr6O17 phase promotes grain cohesion by reinforcing the matrix's phase contact and grain boundaries [23].

However, if single crystals are used in ECAP the deformation process is not affected by grain boundaries and by any interactions between adjacent grains.
The numbers labeled in the high magnification images at the upper right correspond to the numbers labeled in a low magnification image at the upper left.
Figure 3 shows the (111) pole figures at positions having numbers labeled in the schematic Fig.1.
Sub-grain boundaries are aligned in a direction inclined at 45° to the X-axis and the width of these sub-grains is about 0.2 µm which is essentially identical to the grain size of polycrystalline pure Cu after ECAP [14].
Sub-grain boundaries are aligned in two directions inclined at 45° and -20° to the X-axis.

Grain refinement is a promising technique for improving the strength and ductility of wrought magnesium products due to the strong influence that grain size has on the mechanical properties.
A number of previous investigations were performed to predict material behavior under a specified deformation conditions, mechanical anisotropy and so on [3, 4, 5].
Contour numbers represent percent efficiency of dissipation and shaded region corresponds to flow instability [8].
When temperature rises to 400°C, the grain distribution is new and equiaxed grains completely replace the original grains which display full recrystallization occur.
(Item number: 20090322007).

The toughness improvement of the fine-grained HAZ (FGHAZ) and the intercritical HAZ (ICHAZ) is chiefly resulted from the complete decomposition of martensite and M-A constituent.
The simulated welding thermal cycle is identical or similar to the actual one, and five kinds of peak temperature were selected based on the characteristics of the temperature distribution in the actual HAZ, representing the coarse-grained HAZ (CGHAZ, 1350 °C, 1200 °C), the fine-grained HAZ (FGHAZ, 950 °C), the intercritical HAZ (ICHAZ, 800°C) and the subcritical HAZ (SCHAZ, 700 °C), respectively.
The microstructure difference between the peak temperature 1200 ℃ and 1350 ℃ mainly lies in the prior grain size and cooling rate.
On one hand, before PWHT, the number and size of undissolved carbides in FGHAZ are less and smaller than that in ICHAZ, accordingly, after PWHT, big carbides which may be harmful to toughness is seldom compared with ICHAZ.
At the same time, the remaining dislocations form sub-grains, hence recovery and recrystallization of α phase occurs.

Fundamentals of torsion/shear textures and its application to QTA were well-developed and successfully applied to a number of cases in [9, 10, 11], where deformation textures are analyzed in terms of ideal shear orientations.
The nanostructure is described by extremely small grain size and high-angle grain boundaries [1,3].
During the first few turns of a die initially coarse-grained structure is refined in such way that the grain size comes to saturation down to the least value for the given applied pressure and does not change anymore.
At the same time the orientation mapping observations allow to state that the grains are highly misoriented and their spectra resemble to those of nondeformed coarse-grained materials.
Such grains have to be consumed by low dislocation density grains ( A / A - the least Taylor factor) which are assumed to be easily converted to large dislocation-free nuclei of recrystallization [22].

The electron and X-ray images provide maps with the elemental distribution in the lead matrix, in phases, inclusions and grain boundaries.
The materials were prepared by different techniques, for a large number of applications [3, 4].
On the other hand, WO3, which has only limited solid solubility in the matrix of PbO, diminish the number of Pb-position vacancies and causes the existence of O-vacancies in the crystalline lattice.
One can observe an increasing of the W concentration on the crystallite boundaries, as well as grains of unreacted WO3.
The number of the unreacted WO3 grains increases and their concentration in WO3 is higher (Fig. 4).