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In comparison with gas refrigerators, magnetic refrigerators have a number of advantages such as high efficiency, small volume, and ecological cleanliness.
Experimental procedure Two types of CoCr2O4 samples with different grain sizes, as representatives of bulk and nanocrystalline materials, have been prepared by calcining oxides and chemical coprecipitation methods, respectively.
With the crystal size down to nanoscale, the number of magnetically disordered surface atoms increases, leading to a reduced magnetization, simultaneously, the magnetic exchange interaction and magnetic anisotropy deviate from the bulk material, giving rise to a reduction of TC [9].

Hardness value of T10 steel specimen becomes smaller with the increase of impact times, but after 8000 times, it significantly increases along with the increase of the number of impact .At point5, that is after 16000 times, hardness value tends to rising steadily.
XRD map analysis of Specimens Fig 5 Original XRD mapping of T10 steel specimen Fig 6 Static load XRD mapping of T10 steel specimen Fig 7 Impact load XRD mapping of T10 steel specimen Compared Fig 5, Fig 6 and Fig 7，we know that the specimen, before and after the experiment ,are different in peak position and number of peak .Crystalline phase index is also different, and its ratio follows: 1:2:3:4:5:6:8:9:10:, 1:2:3:4:5:6:8without 7,both complying with simple cubic crystalline structure types.
Table 1 Parameter values when the diffraction intensity I = 100% Parameter character of load, 2θ[Prague diffraction Angle] Average grain size[nm] Micro strain[nm] Faces spacing[nm] Crystal area[nm2] original 44.57 29 -0.1076 0.20363 1462 Static 44.561 29.4 -0.1253 0.20316 1345.8 Impact 44.603 29.6 -0.1273 0.20349 1335.5 Interplanar spacing and crystal area are smaller, yet crystal size and microscopic strain are getting bigger after static load or impact load.

Heat source model Fig.1 Illustration of the grinding zone heat source Journal Title and Volume Number (to be inserted by the publisher) 255 When t � � , the process of heat conduction reaches its quasi-steady state in the moving coordinate.
The reason is that with an increase of the feed speed, the cutting thickness of each abrasive grain augments correspondingly, so the grinding force and energy rise notably.
It can be obtained from the Fig.6b that the adoption of an appropriate and higher feed speed of worktable makes the temperature field of Journal Title and Volume Number (to be inserted by the publisher) 257 workpiece more homogeneous and improves the surface quality of workpiece.

Experimental The �-Fe-Ni nanoalloy powder in the form of agglomerate consisting of 40 nm grain size was fabricated by hydrogen reduction of Fe2O3-NiO powder at 600 o C for 1h.
It was interesting to note that, the average size of inter-agglomerate pore in the PIM part (brown part) Journal Title and Volume Number (to be inserted by the publisher) (a) (b) (c) (d) (e) (f) (g) (h) 800o C Brown part 1100o C 650o C PIM PM 50µµµµm 400 500 600 700 800 900 1000 1100 0 5 10 15 20 25 30 35 (a) ����V / V0 (%) Temperature ( o C) PIM PM 400 500 600 700 800 900 1000 1100 0 5 10 15 (b) Temperature ( oC) d(����V / V0) / dt [10 -4 s -1 ] 400 500 600 700 800 900 1000 1100 0 1 2 3 4 (c) Shrinkage anisotropy Temperature ( o C) Fig. 2.
Vol. 38 No. 1 (2002), p. 51 Journal Title and Volume Number (to be inserted by the publisher) [6] E.S.

These damaged cells are dispersed,initially.With the number of broken cells increased,the ruptured cells gathered gradually,micro-fracture led to micro-cracks`s generation.And micro- cracks,with the hydraulic pressure`s increase,extends along the horizontal direction substantially to form a horizontal macro-cracks. rock samples are not instability and failure, although the macroscopic crack has been generated.That is the wall of pore began to crack under hydraulic pressure ,does not mean samples are damaged all along or unstable propagation of crack.
We can read from the figures, the general direction of macroscopic crack`s extension does not change much, but remain level.High water pressure and high stress areas moves along crack tip, hydraulic pressure distribution becomes oval,because of the increased number of adjacent destroyed cells.Increased stress area transfer to the crack tip to promote crack propagation.Due to the non-uniformity of the rock material, it could be found in figures that the size, length, extending direction of two crack is not identical.
Observations of intergranular stress corrosion cracking in a grain-mapped polycrystal[J].

, (5) Where the Empirical constants =0.09; Turbulent Prandtl number =1.0,=1.3; Equation constants =1.44,=1.92; the turbulent kinetic energy production caused by mean velocity gradient , (6) two-phase flow related to the flotation cell fluid flow equation is established.
The greater pressure difference is, the greater saturation gas dissolved in the slurry is, the smaller the surface energy is, the more number of the precipitated bubbles is and the smaller the bubble diameter is[10,11].
This can significantly reduce the induction time of the flotation and reinforce the selective sorting of fine-grained materials[12].

There have been a number of investigations of carrier lifetimes [1], and in recent years several studies of post-growth improvements of the carrier lifetime [2,3].
These features are either related to high dislocation densities, such as grain boundaries, or stripe-like features normally orientated perpendicular to the [11-20] off-cut direction.
A rough estimation of the individual radial wafer rotation rate and the gas flow speed over the substrate gives comparable numbers.

This is parallel to the findings of Grimes et al whereby heat treatment of TNTs at high temperature results in the oxidation of the underlying Ti foils accompanied by grains growth, destroying the nanotubes structure completely [6].
Anatase peaks are 25.2o, 37.8o 48o and 53.8o with ICDD number of 00-021-1272.
It will reduce the number of charge carriers reaching the electrode.

The potential approximation will approach the true potential when the number of segments increased.
All materials in solid form was previously crushed for 3 hours in order to obtain refined grains, and then shaken manually for 1 hour to produce precursors.
It is because when an increase in bias voltage, the number of electrons that goes through n-p heterojunction will increase as well.

In principle, a number of glass-ceramic systems could be used to give the characteristics required for sealing to metals and alloys.
Materials from the Li2O-ZnO-Al2O3-SiO2 system do, however offer a number of distinct advantages over other candidates.
The spherical grains with a size of 0.2-0.5um and close similar microstructure can be observed from Fig. 3(c) and (d), which shows the microstructure of the glass-ceramics obtained by treating K0 and K3 at 820°C for 2h respectively.