Search results

The reason for the peak decreases is probably that more ionized Al3+ combine with O and form Al2O3 while substrate temperature further increasing above 300℃, which reduces the number of the substitute Al and carrier concentration.
Comparing these figures, it can be seen that the grain sizes of the AZO films increase when sputtering power rises from 90W to 180W and the crystallization improves.
(a) 90W (b) 150W (c) 180W Fig.3 AFM images of AZO films deposited with different sputtering powers at 150˚C Comparing the AFM images of the AZO film samples in Fig.4, which were prepared at substrate temperatures of 200˚C, 300˚C, 400˚C with sputtering power 180W, we find that the grains are clearer and their sizes bigger when the substrate temperature rises from 200˚C to 400˚C, and that the size difference of the grains is smallest and crystalline quality best at 300˚C.
This means that the carrier concentration and mobility rise, which is caused by the size enlargement and scattering reduce of the film grains.

Huang[5] and Sanoj[6] reported that the sintering temperature of MgTiO3-CaTiO3 ceramics doping with a large number of B2O3 glass can be decreased to 900~1050°C.
The changes in the amount of glass and grain size can be seen clearly in the SEM photographs.
The increase in the bulk density was due to the elimination of pores and enlarged grain size as observed in Fig.2.
However, it slightly decreased at temperatures higher than 1255°C for specimens owing to a rapid grain growth.
Dielectric loss is caused not only by the lattice vibration modes, but also by the pores, the grain morphology and the second phases [10].

It is well known that a large number of practical properties of magnetic materials are considerably affected by their particles size and consequently specific surface area [6-8], which are promising in magneto-optics device, gas sensor device and for using in catalytic applications.
Fig. 4b is related to cell wall of achieved porous structure, shows that the main grain growth occurred in smaller particles in comparison with as synthesized powder (Fig. 2).
Also, it could be seen that the particles arranged in cell wall exhibits no significantly grain growth and their particles size are approximately about 80-120 nm.
Incompletely sintering could be attributed to low temperature sintering and solid state sintering phenomena, which is desired for dramatically grain growth prohibition.
Also, no significantly grain growth, was observed during the sintering stage and mean particles size of cell wall were about 100 nm.

And after selecting the sintering process parameters of curve 2 and sintering with a high temperature of 1450°C, the stoma number of the sintered sample cross-section can be reduced and relatively scattered.
The 20,000 times SEM image can be clearly seen that the sintered ceramic substrate has a continuous grain boundary.
The sintered grain size is between 0.8 ~ 0.9 um, pore size is about 0.52 um when the highest sinter temperature is 1450°C.
And the sintered grain size is between 0.6 ~ 0.7um and the pore size is about 0.6um when the highest sinter temperature is 1500°C.
Thus, selecting the appropriate sintering temperature curve can make sectional size of the grains in the sample become larger, the size of the pores smaller and the ceramic hardness and relative density increase.

Its transfer matrix consists of four elements in the form of a 2×2 square matrix and can be described as a transformer characteristic equation:              − − =            =      1 1 1 1 2221 1211 2 2 cos sin sin cos F u LLcj cS Lj L F u aa aa F u & & & κκρ ρ κ κ (3) Wherein: ρis density; L is the length of the cylinder; S is the sectional area; c is the wave velocity propagating in the cylinder and ρ E c = ; E is elastic modular; κis wave number and c ω κ=
To study on the traces of abrasive grains in ultrasonic vibration, a honing gear cutter with less CBN grains is electroplated.
Fig. 7 Test machining traces of the honing wheel with less abrasive grains Left: in traditional gear honing; Right: in ultrasonic gear honing The ultrasonic gear honing is carried out with normal honing gear cutter and the machining results show in Fig.8.
Fig. 8 Normal machining trace of the abrasive grain Left: in traditional gear honing; Right: in ultrasonic gear honing Conclusions Investigations above may lead to the following conclusions: (1) The equivalent four-terminal network is an effective method to design complex horn vibrating longitudinally.

A number of factors such as the fiber characteristics (content, length, thickness, modulus, tensile strength and failure strain) and the soils characteristics (grain size distribution and mean particle size) influence the behavior of the soil-fiber composite [14].
The grain size distribution curve is shown in Fig. 1.
The grain size is entirely fine sand with an effective diameter of 0.16mm, and uniformity and curvature coefficients of 1.9 and 1.2, respectively.
Grain size distribution curve Drained Standard Triaxial Tests The compacted soil and fiber-reinforced specimens used in the triaxial tests were prepared by hand-mixing dry soil, water and curauá fibers (when used).

CaO MgO K2O Na2O I.L White ball clay 51.33 33.45 0.60 0.35 0.46 0.20 0.15 0.22 12.91 Feldspar 73.30 14.94 0.14 0.10 0.56 0.12 4.42 6.19 0.16 Burned talc 62.66 0.04 0.12 0.26 3.10 30.76 0.16 0.12 0.36 Albite 73.34 16.54 0.15 0.11 0.29 0.14 0.15 8.83 0.47 Dolomite 2.58 0.66 0.12 - 30.18 19.11 - - 44.73 General quartz 99.11 0.45 0.08 - - - 0.06 0.08 0.22 Melt silica quartz 98.95 0.56 0.12 - - - 0.12 0.14 0.10 Table 2 Technological properties of the main raw materials used in this paper Name of the raw materials Color The whiteness and the show after sintering（1200℃,75min） White ball clay Black brown 78 deg, no glass phase, a little yellow Feldspar White 55 deg, glass phase exists Burned talc White 56 deg, glass phase exists Albite Pure white 93 deg, no glass phase Dolomite White 92 deg, no glass phase General quartz White 90 deg, no glass phase Melt silica quartz White 90 deg, no glass phase Experimental Formulas and Technological Process Based on the relevant documents and a large number
Test Analyses and Discussion Study of Basic Formula Based on scattering loss theory, incident light will be scattered, refracted and reflected when goes to porcelain tiles, due to some factors such as porosity, impurities, grain boundaries, roughness of phase boundaries, additive types and content, sintering system including sintering temperature, heating and cooling mode, thermal insulation, sintering atmosphere, forming pressure, thickness of products and surface active substances, etc, which is shown in Figure 2, so light transmittance of porcelain tiles are usually lower. [3] As scattering particles, pores and impurities in the porcelain tiles are similar in the mechanism of light loss, differing only in the refractive index.
In addition, there is a second phase or more phases on the grain boundaries that is different from the main phase in the optical properties, which undermines optical uniformity of porcelain tiles.
When there are lots of grain boundaries per unit volume or grain configuration is disorderly, incident light will be reflected and refracted continuously, which also reduces the light transmittance.

Experimental The commercial BaTiO3 powders (Shandong Guoci Company) were synthesized by a hydrothermal method with the average grain size of 120nm.
Although more flux was beneficial for ceramics densification and mass transfer, more paraelectric phase in the shell of the grain would dilute the ferroelectric properties and depress the permittivity.
When the flux content was higher than 0.8wt%, glass phase would occur on the grain boundary, which affected dielectric constant little.
The factor influencing IR change is mainly related to the number of charge carrier which reduced IR of the samples.
The dense ceramics show very fine and homogeneous microstructures with the average grain size about 160nm.

With the addition of Sb (Fig. 2(c)) or Sr (Fig. 2(d)), microstructural changes can be clearly observed: (1) morphology of the Mg2Si phase has modified and refined from coarse Chinese script shape to polygonal shape; (2) the average grain size of α-Mg matrix also refined (36 to 31µm on average).
With addition of Sr or Sb, finely distributed polygonal type Mg2Si particles are formed at the interfaces of liquid-solid phase during solidification, thereby it might restrain further growth of α-Mg matrix grain.
It may be attributed to three aspects : (1) the suppression of formation of thermally unstable β phase ; (2) morphology modification of Mg2Si from coarse Chinese script to refined polygonal shape; (3) distribution of larger number of refined Mg2Si particles with thermal stability distributed in the grain boundary and pinning the grain boundary sliding during creep.

The ‘n’ values in these BSCCO system refer to the different number of Cu-O planes which are perpendicular to the c-axis in the crystal structure.
By adding nanoparticles into the BSCCO system, it will settle easier among the grains of these cuprate superconductors due to their tiny size of nanoparticles [7].
Consequently, introduction of nano-size rare earth elements to the (Bi,Pb)-2223 superconductor system will improve the connectivity between the grains.
Previous work by [13] explained that smaller grain size resulting in weak connectivity between the grains thus decrease the JC values.