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This indicates that there are very small grains or amorphous phase of CuO in samples.
The CuO mingling and the second sintering resulted in grain growth and specific surface area decreasing.
It is believed that the contact between CuO and SnO2 grain formed a p-n junction which resists electron transfer.
The high response is possibly ascribed to the less grain size and higher specific surface area.
The maximum responses to H2S of CuO coated SnO2 were higher than that of the CuO doped SnO2, which may be related to the number of electron channel.

For example the material removal in the high speed deep grinding of alumina and alumina–titania was dominated by grain dislodgement or lateral cracking along grain boundaries, while the removal for zirconia was via both local micro fracture and ductile cutting [6].
In contrast, however, the share of grit splintering increases, leading to an increase in the number of single cutting edges.
It’s necessary for the trued wheel to be electrically pre-dressed to form insulating layer composed of the oxidized bonding material and protrude the grains on the wheel surface.
As grinding begins, the grains and the oxide layer begin to wear.
The protrusion of diamond grains from the grinding wheel therefore remains constant.

At the initial stage of compression, there is higher dislocation density on account of a large number of dislocation multiplication and dislocations tangle.
The grain orientation is represented by different colors.
From Fig. 10, what can be seen is that at deformation temperature of 150 ℃ and strain rate of 0.001 s-1 and, more than 90% of the grain size is below 10 μm; at strain rate of 1.0 s-1, approximately 65% of the grain size is below 10 μm.
It can be concluded that under the condition of low strain rate, the deformation of the alloy is more coordinated and the grain is refined.
Fig. 10 Grain size histogram at 150 ℃: (a) 0.001 s-1, (b) 1.0 s-1.

Hydrogen interacts with the microstructure defects such as precipitates, voids, vacancies, dislocations and grain boundaries promoting segregation [2].
On hydrogen attack, the hydrogen dissolved in the microstructure reacts with carbon in the lattice and carbides, forming methane inside the grain boundary cavities.
The increase on internal pressure because of the gas in the voids, plus the effect of the surface and grain boundary diffusion and dislocation creep, makes the voids grow.
The precipitates tend to take place in grain and inter-lath boundaries, see Fig. 2.
This phenomenon reduces the number of hydrogen trap sites considerably, mostly in the vanadium added steel which the lower energy trapping site loses a considerable part of its trap capacity with tempering, Fig 4.

While Cu-C binary phase diagram and previous works [13,16,17] showed that C had no solid solubility in Cu, so C could only exist at the defects, grain boundaries, etc.
Cu grain had grown distinctly in the film, which indicated that Sn was dissolved in the Cu film, and the number of C elements was insufficient to fill the Cu diffusion channel, so it could not prevent the Cu grain growth completely.
The Cu grain growth after annealing was helpful for the annihilation of defects and decreasing of grain boundaries, which leaded the diffusion of C atoms to the interface.
Cabral, et al, Annealing behavior of Cu and dilute Cu-alloy films: Precipitation, grain growth, and resistivity, J.

The grain size is less than 4um.
Table 2 Non metallic inclusions in as-atomized powders (1 kilogram powder) size range + 150 um -150 um + 75 um - 75 um + 45 um number 11 7 5 Microstructure of consolidated PM HSS materials.
There exists a fine microstructure in the as-HIPed HSS materials, with fine carbides less than 3um evenly dispersed in the matrix, the grain size is lee than 5um.
Owing to the anchoring effects of carbides at the grain boundaries, the grain growth was hindered and the grain size was kept less than 5um even after austenetizing at high temperature of 1220°C.
(2) The as-HIPed and forged PM HSS materials exhibit a refined structure and even distribution of carbides, with grain size less than 5 microns and carbides less than 3 microns.

The average grain size was determined in accordance with GOST 5639-82.
The structure of BM steel 09G2S (figure 1, a), is a ferrite-perlite mixture with a volume fraction (VF) of the ferritic component FVF = 68% and the size of the ferrite grain DF, varying within DF = 5.02-10.40 microns.
In the metal of WM welded joints of series 3 and 4 set of experiments, the volume fraction of ferrite and the size of the ferritic grain are the values of FVF = 60-66% and DF = 5.24-5.36 µm, respectively.
With a sample of series 1 (DCW), figure 2, a, dendrite-like the structure contains large grain sizes compared to the microstructural elements of the sample series 2nd set of experiments (CMW), figure 2, b.
The dimensions of dendrite-like grains in the second case (CMW 2) are smaller, which confirms the previously established effect of structure refining as a result of a pulse change in the energy parameters of the welding mode.

Because increasing the number of grinding balls equals to reduce the space between the balls, leading to a size decrease of the compound granule. 4mm (a) 4mm (b) 4mm (c) Fig. 2.
Regardless of the refinement effect of ultrasonic vibration, the nano-SiCP embedded on the grain boundary will inhibit the growth of the grain.
Because the nano-SiCP cannot be captured by the growing crystals, so they have refinement effect on the grains during solidification.
With the temperature drops to the solidus, the eutectic reactions located in the inter-grains occur, and these nano-SiC particles pushed by the growing grains will be surrounded by the eutectic phases (Fig. 7a).
In addition, nano-SiC particles concentrate at the grain boundary can hinder the dislocation slip because of their high elastic modulus and high hardness.

From the manufacturer's point of view, the range of materials that can be rolled per calibration and the resulting minimisation of roll or pass changes, the minimisation of roll wear to increase roll service life or the possible numbers of exit cross-sections per calibration are significant cost factors.
The large number of free optimization parameters often cause problems due to a necessary high number of iterations for classical optimization approaches and the use of e.g. conventional finite element tools.
The resulting yield or tensile strength values for steels are functions of the chemical composition of the matrix [Xj, ss], the ferrite grain size Dα, the pearlite colony size p or the cementite lamella spacing S0, among others.
· · · + 63.1[Si] + 425 p [Nsol] (5) Rm = 3pfα �246 + 1142 p[Nsol] + 18.2 √Dα� + �1 − 3p f� � 719 + 3.56 √S0� + 97[Si] (6) To close the system and predict the necessary austenitic grain size Dγ, effective strain before phase transformation εeq as well as the cooling rate ˙T relationship similar to those of Equation 7 to Equation 13.
Number: 20, pp. 492-517

Polypropylene powder: TC-0, standard of Q/HC001-1898, lot number:12148101, China National Bluestar Group Corporation Tianjin Branch made. 1010 antioxidant: food-grade, CIBA Company. 168 antioxidant: food-grade, CIBA Company.
×100 (1) A—ink adhesion fastness; A1—grid number of ink mark layer; A2—grid number of scraped ink layer Toluene residue Put PP sheets in 60℃ oven and weighted after 24h drying.
This phenomenon indicate that the addition of nano SiO2 attribute to the heterogeneous nucleation, the nucleation point increased with the increasing of nano SiO2 proportion, thus the increased number of spherulite lead to the reduction of spherulite size.
The reason maybe that the addition of nano SiO2 provided more nucleation points but it also made the grain size reduced which is bad to the integrity of crystal lattice and thus lead to a decline of PP crystallinity.
Small grain size made the toughness of sample 2 increased to a large extent, and its breaking elongation enlarged 4 times when tensile strength remained the same (seen in table 4 ).