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As the rotation of the body in the process of unloading, the surface has a Reynolds number is Re, (3) u—line speed, ；—perimeter of the revolving body,; V—kinematical viscosity of air.
Body part is a circular pipe still, belonging to the state of natural convection, as the calculation of the convection coefficient: (5) In the formula: d—projectile diameter; Nu—Nusselt number
(6) Gr is Grashof number, the size is: (7) In the formula: g—acceleration of gravity; —expansion coefficient
According to the characteristics of ammunition propellant ignition, generally at higher ambient temperature, the ignition is not due to grain internal heat accumulation, but because of the high local temperature and decomposition reaction, or is directly caused by the local ignition, resulting in the propellant explosion.
The temperature is increased with the increase of speed, the amplitude of temperature rise is not obvious, no risk for grain, safety conclusions rotary unloading process.

As showed in Fig. 1, the number and size of droplets on coating surface decreased when N2 partial pressure increased from 0 Pa to 0.6 Pa.
It has been shown that melting point of target materials affects the number and size of Fig. 1.
But when N2 partial pressure got to 1.2Pa, there were an increase in number and size of droplets and some part of the coating peeled off (Fig. 2).
It can be observed that the number and size of the droplets on the coating surface decreased with increasing pulse bias voltage.
The crystalline grain of oxide was fine and oxide scales were thin for both (Ti,Al)N and (Ti,Al,Y)N in less than 10 hours at this temperature.

Introduction The great interest to nanotechnologies is explained by the possibility of changing significantly and sometimes imparting new in principle properties to known materials at their transition into the nanocrystalline state (about 100 nm); such effects are more distinctly expressed when the grain size is smaller than 10 nm [1].
When the grain size is changed by four orders of magnitude by cold rolling, the hardness of nanostructured maraging steel is 5 GPa (510 kg/mm2), which is 12 times as that of high-strength carbon steel [5].
It is also known that nitriding in a confined space has a number of advantages over other advanced methods for saturation with nitrogen [6, 9].
At the treatment in the confined space under the air low pressure (about 0.1 MPa), it is possible to significantly change the surface properties of a number of nanostructured stainless maraging steels and ferrite iron-chromium alloys [13 – 15]; the interaction of the atmospheric nitrogen with the surface results in the formation of nitrogen austenite (gN).
It has become the basis for the method for high-temperature nitriding with the air nitrogen which can be considered as nanotechnology due to a number of its characteristics (the use of ultralow pressure of atmospheric air with narrow ranges of the appearance of the effect of higher nitrogen solubility in the high-temperature g-phase) [12].

The Hardness Number as a measure of the degree of plastic deformation Hardness tests have been conducted for a long time to characterize materials, mostly because of their characteristics (simple, non-destructive, low-cost), as well as for their capacity to assess low-volume mechanical characteristics, [1].
As known, [2], the hardness Number represents a measure of degree of plastic deformation suffered by some materials.
For normal 1C45 (1.053) steel, the graph of Fig. 2a allows the conclusion that high hardness values are registered in the zone where fatigue crack was initiated, which required a significant number of loading cycles, about 120.000.
Vickers hardness increases in the area of the sudden fracture of the specimen (the final zone, with bigger and more brilliant grains), the values registered in this zone occurring within a certain level.
The hardness values are higher in the zone where the fatigue crack is initiated, for which a relatively high number of fatigue cycles are necessary.

a) d) g) b) e) h) c) f) i) Fig. 2 Morphologies of dendrite growth with and without heat flux Compared with the extraction boundary condition, under the Zero-Neumann boundary condition the under-cooling was smaller, while the growth rate was slower, and the number of secondary dendrite arms was less.
The disturbance at the interface was difficult to be amplified and the number and size of secondary branches was the least, so the solute can be diffused fully.
Fig. 7 The Peclet number of dendrite growth process versus time As can be seen in Fig. 7, with the increase of temperature the simulation result became gradually consistent with Ivantsov function.
Grain growth competition during thin-sample directional solidification of dendrite microstructures: A phase-field study [J].
Growth competition of columnar dendrite grains: A phase-field study [J].

When coupled with large and variable grain sizes, the HCP structure has in the past lead to less than optimum mechanical properties.
While the weight savings with magnesium has the potential to be enormous, in comparison with aluminum the tensile strength of magnesium is approximately 25% less, fatigue behavior (number of cycles to failure) is 35% less, hardness 30%, modulus, 40%, and thermal expansion 15% less.
(9) Where cσ∆ and p cε∆ denote local stress and strain of a randomly distributed single crystal while σ∆ and p ε∆ are the overall stress and strain that are considered as the average of the local stresses and strains over all randomly distributed single crystal grains. 1 1 i � p p c i� ε ε ' = ∆ = ∆ '∑
Stress-strain hysteretic loop data were captured following linear increasing cycle number basis at the first 5 cycles.
As observed in Figure 10, the cyclic mean stress mσ decreases with increasing cyclic number N for AM60 with strain amplitude aε =0.3% and R ratio R=0.7 obviously.

In cyclic conditions, the weight gain vs. cumulative cycle number curves showed approximately parabolic behavior at 850 and 950°C.
Cycle number 0 25 50 75 100 125 150 Mass variation (mg/cm²) -2 -1 0 1 2 3 Fe-17Cr-0.4Ti Fe-17Cr Fe-17Cr-0.2Ti Fig. 4.
Number of cycles Fe-17Cr Fe-17Cr-0.2Ti Fe-17Cr-0.4Ti 150 0.7 % 0.23 % 7.3 % 300 0.02 % 0.54 % 3.2 % Oxide characterization.
It was also observed on the cross sections that both reference and low-Ti grades exhibited marked interface undulation, whereas the high Ti grade exhibited a flat interface, except at the locations of grain boundary emergence.
Scale adhesion seemed to be directly linked to chromia scale keying into the steel substrate at locations of grain boundary emergence.

Introduction In the effective short fatigue crack (ESFC) criterion proposed by Zhao et al. [1], the definition of ESFCs density is the average number of micro-cracks per unit area in the initial zone of dominant ESFC (DESFC) in MSC stage.
Compressive residual stress and heavy plastic deformation imposed on the surface grains due to cold work make it difficult for the cracks to nucleate and propagate at the rolled surface [7, 8].
C1 and C2 in Fig. 3b coalesce with each other and become a new crack C1 in Fig. 3c, the total number of micro-cracks increases stably.
Crack numbers of Fig. 3d-e are 9 and 11, respectively.
Compressive residual stress and plastic deformation are imposed on the surface grains and make it difficult for the cracks to nucleate and propagate at the rolled surface.

It requires the investigator to live together with the investigated objects for some time, and to observe, to understand and to be awareness of their social as well as cultural from it. 1.2 Research object On March 23, 2011, we chose Huofeng village of Quejia town as our research object, and selected a number of local residents to face-to-face interview while we observed.
Obviously, the interests of farmers of relatively weak competitiveness are severely squeezed. 2.2 Existing problems First, returning farmland to forest makes the local ecological environment greatly improved, the forest coverage rate significantly increased and wildlife species and amount apparently increased, but also leads to a surge in the number of grain-eating birds, which causes the prominent phenomenon that “human fighting birds over food”.
The nation pays attention to agriculture, rural areas and farmers, and gives out a certain amount of agricultural subsidies, but “agricultural subsidies” is a complement to the plot of farmlands, and there is no subdivision of whether to grow grain, so some farmers live the farmlands fallow to work outside the home on the one hand, and on the other hand still get the agricultural subsidies.
After a number of years, they will go back home use the accumulation to rebuild their houses.
A large number of young labor outflow causes seriously lacking of young adults, and the average age of the village leadership is about 60-year-old.

However, compared with experimentally measured temperatures and nodule size distributions it has been shown that such a solidification model underestimates the nodule number density after solidification is complete.
The number of new nodules as a function of time and temperature is given by the open circles in Fig. 2a.
Instead multiple nodules can be embedded in the same austenite grain.
Numbers refer to the particles described in Fig. 6.
Atwood, Transgranular liquation cracking of grains in the semi-solid state., Nat.