Search results

Introduction To ensure grain security, China set a "red line" demarcating that its arable land never drops below 1.8 billion mu.
But with the acceleration of industrialization and urbanization, on one hand, the contradiction between population increase and farmland decrease has been intensifying, that pushing the “red line” to a precarious situation; on the other hand, a large number of farmland was artificially abandoned.
So, under the condition that the productivity of farmland can not be improved easily, whether the limited farmland can ensure the national grain security or not, that is what we need concern and consider.
The main reason is that the investment policies of local government and establishment of Industrial Park caused a large number of farmland to be contracted, that provided local farmers with more local employment opportunities.
The contractors contracted a large number of lands for tourism and large-scale management of agriculture.

This is because the NaOH ionization produce a large number of OH- ions in the water after it add to the slurry.
This paper argues that the reason of the phenomenon is: (NaPO3)6 ionization and produce a large number of PO3- ions in the water.
A large number of PO3- ion are selectively adsorption by Al2O3 particles into solid phase.
According to Woodcock formula [8]: (1) where h is the particle spacing, d is the grain diameter and Φ is the volume fraction of solid phase.
We can see the volume fraction (mass fraction) of solid phase is inversely proportional with the spacing of particles while proportional to grain diameter.

Introduction There is a number of features that can be achieved by materials processed by Severe Plastic Deformation (SPD) only, i.e. not by otherwise processed nanomaterials.
Probably due to refined grain structure caused by HPT deformation, desorption of hydrogen in HPT processed sample occurs at an about 35 K lower temperature with respect to the undeformed one.
Furthermore, positron annihilation and neutron scattering investigations should clarify the number of vacancies in the vacancy clusters.
(4) The high stability and number of vacancy type defects can be attributed to the formation of vacancy-hydrogen clusters.
Symp. on Ultrafine Grained Materials, ed.

In order to analyze intuitively, set number of levels of factors as abscissa and the tension-shear force of welding joint as ordinate, then the standard curve was obtained, as shown in figure 2.
The cross-section morphology of number 5, 6, 9, 12, 15, 18 are comparatively good and their penetration rate of nuggets are high; while the phenomenon of incomplete fusion happened in the joints in number 4, 7and 13, that is because of low welding current, short welding time and great electrode pressure; the cross-section morphology of the joints of number 1, 2, 3, 8, 10, 11, 14, 16, 17 are poor and penetration rate of nugget are low, as shown in figure 3.
The nugget is composed of swirling organization, with copper and a little of nickel uniformly distributed in weld nugget (Fig.4d and Fig.4e); the microscopic structure of nickel-plated steel (Fig.4b); the edge microscopic structure of nickel-plated steel and nugget (Fig.4c); the edge microscopic structure of copper and nugget is coarse columnar grain, heat-affected zone is coarse equal grain (Fig.4f); the microscopic structure of copper is streaky structure of rolling (Fig.4g).

When the average grain size of such materials reduces to nanometer level, nanostructured WC/12Co (n-WC/12Co) coatings can be obtained, which exhibit a great improvement in strength, toughness and wear resistance over their conventional counterparts.
Table 1 Physical Properties of n-WC/12Co Coatings Powder grain size [nm] Density [g/cm3] Fracture toughness [MPa·m 1/2] Vickers hardness [GPa] Elastic modulus [GPa] Poisson's ratio 30-50 14.50 5.5 13.50 405 0.30 Table 2 Specifications of Diamond Wheels Diamond wheel SD600N100V SD2000N100V SD600N100B SD80N100B Notation 600V 2000V 600B 80B Wheel diameter, [mm] 200 200 200 200 Grit size, [µm] 25 10 25 210 Active grit number of unit area 30 100 60 5 Bond type Vitrified Vitrified Resinoid Resinoid Experiment Results Grinding Forces vs.
The number of active grits would be more with the resinoid bond wheel and the workpiece, and therefore, a larger grinding force would be resulted.
The number of active grits was more when using smaller grit wheels as compared to larger grit ones.
Fig. 2 Normal grinding force vs. workpiece federate The aforementioned results can be explained in terms of the active grit number per unit area.

Sand is the ordinary river sand, which belonged to medium sand.The maximum grain size is 5mm.
Coarse aggregate is granite stone, its grain size is 525mm.
Mix ratio of cement concrete Specimen number Material dosage/kg/m3 Cement water ratio Cement Water Sand Gravel Recycled plastic partcle A0 0.43 370 160 624 1306 0 A2 0.43 370 160 606 1306 7.4 A5 0.43 370 160 580 1306 18.5 A8 0.43 370 160 554 1306 29.6 A11 0.43 370 160 527 1306 40.7 Experiment Results and Analysis Cubic compressive strength.
Table 3.Test result of split tensile strength and compressive strength Specimen number Splitting tensile strength/MPa Compressive strength /MPa tension-compression ratio A0 2.07 37.44 1/18.1 A2 2.71 38.91 1/14.4 A5 3.08 44.81 1/14.5 A8 2.82 41.19 1/14.6 A11 2.64 39.64 1/14.6 Fig.2.
Result of bending strength test Specimen number Bending strength /MPa Compressive strength /MPa Bending strength / Compressive strength A0 4.35 35.57 0.122 A2 4.80 36.96 0.129 A5 5.05 42.47 0.119 A8 5.03 39.13 0.128 A11 4.93 36.71 0.134 Fig.3.

A trend in the development of WC based cemented carbides and zirconia based ceramic composites is grain size refinement and more narrow grain size distributions of the starting powder, in order to accomplish higher hardness and abrasive wear resistance.
This stress can easily be converted to a dimensionless number for determining the mechanical severity of contact [2,3].

This reduction is related to the segregation of this reactive element to the metalalumina interface and the alumina grain boundaries, which inhibits outwards Al diffusion in the αAl2O3 [15].
Finally, an additional interest must also be taken in the grain structure of the bond coat prior to oxidation.
It has been shown that the refinement of the bond coat grain size could lead to an increase in scale spallation during cyclic oxidation at 1150°C [15].
Tolpygo et al. [28,29] observed a thicker alumina scale on small grains, attributed to faster oxidation occurring at the oxide grain boundaries.
These results suggest that an increase in the grain size is closely related to the reduction of the oxide growth rate [30], which, in turn, should have a positive effect on the adhesion of the alumina-scale.

In recent years, the development of automated control systems, has become of special urgency, which is reflected in a number of scientific papers [6].
The microscopic picture of the material structure is referred to as microstructure and is characterized by the number, shape and arrangement of the phases, and grain size and anisotropy, that effect the mechanical properties of alloys.
Generatrix connections are characterized, above all, by arity value which reflects the maximum number of connections that bind this generatrix and the surrounding generatrices.
Therefore, the chi-squared test is applies independently for each of the classes, with number of tests .
Summary The complexity of functional materials quality control problem is accounted for by its enormous information capacity due to the high level of detailization, determined, firstly, by a very large number of microstructure elements (grains, phase areas, their boundaries, and so on), secondly, by defects of this microstructure due to extraneous inclusions, cavities, cracks, etc., and, thirdly, by shooting defects (defocusing of separate parts of the image, glare, table shake, etc.).

With the naive Bayes classifier it is possible to categorize the clusters more fine-grained and faster than with a correlation function.
Every cluster receives a unique ID-number after the extraction from the measurement signal.
So PAC is a real number between zero and one (10) [17-21].
The relatively small number of major clusters that are converted subsequently to classes is very suitable to train in clusters around the naive Bayes classifier in combination with the total number of clusters.
With the classifier it is possible to categorize the clusters more fine-grained and faster than with a correlation function.