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We then multiplied the mean number of pollen grains per anther by the number of stamens per flower to estimate the number of pollen grains per flower.
The P/O ratio was finally calculated as the number of pollen grains in one anther divided by the number of ovules.
The number of pollen grains that changed to red color per 100 pollen grains was taken as the pollen viability index [4].
The pollen grain numbers, ovule numbers, and P/O ratios for this species are given in Table 1.
The pollen grain number, ovule number, and P/O ratios for Calligonum Mongolicum Stamens no.

With increasing the number of rolling steps, the content of CNTs coated on the Cu powder surface increased because of the increment of the flat surface area of flaky Cu rolled powder.
CNTs distributed at primary particle boundaries were effective to prevent the grain coarsening by their pinning effects, and this grain refinement was the main strengthening factor of the Cu-CNT composite via rolling process.
These raw materials are shown in Figure 1.The grain size of Cu powder was about 3μm.
The grain growth was promoted during sintering even though dispersed with Cu2O particles.
Fig.7 Relationship between yield stress and grain size of extruded materials.

The properties of welded joint will been improved by these fine crystal grain.
Following the increasing of magnetic field current, the number of α-Mg increases and displaies as equiaxed grain, the β-Al12Mg17 is diffusion distribution at the grain boundary of α-Mg.
The grain consists of coarse α-Mg and series β-Al12Mg17.
Large surplus of aluminum accumulate along the grain boundary at this time, which make the Aluminum rich in grain boundary and segregate the α-Mg.
The crystal grain will be coarsening and the properties of welded joint will deteriorate.

In fully recrystallized samples, grain size measurements were done by using line intercept method (ASTME112) to obtain grain growth versus annealing time relation at different temperatures and plotted in Fig. 1.b.
Nucleation observed (a) along the grain boundaries and (b) inside the twins (white circles).
The presence of more complex deformation mechanisms in swaging, which probably generated higher stored energy and larger numbers of preferred nucleation sites, is believed to be the reason of differently sized grains obtained after the same heat treatment.
Preferred nucleation sites were observed to be the twinned regions and grain boundaries.
Grain growth kinetics of bulk AZ31 magnesium alloy by hot pressing. 

Although the Linux system has a number of security mechanisms, such as identity and authentication mechanism, file access control mechanism and capacity mechanism, there are still security flaws.
The ACL can control any single user, ACL’s file access control is more detailed, fine-grained.
The structure also contains a number of auxiliary fields, for the quick search of subjects or objects. 5 CONCLUSION In this paper, we researched the access method of Linux files, and studied the Linux Security Module (LSM).
LSM can not deal with the issue of fine-grained access.
So the paper designs a mechanism for fine-grained access called ACL.

Furthermore, small addition of MgO caused the second crystalline phase in the ceramic structure and higher concentration of MgO produce an increased number of second crystalline phases (spinel) [7,8].
Apart from that, the addition of MgO led to an increase in densification and decrease in porosity that occurs in ceramic samples, the increase in densification occurs because of magnesia at grain boundaries which reduces the mobility of the grain boundaries, magnesia can also increase the grain boundary energy and consequently increase the surface diffusion mobility Al2O3 pore trapped in the grain increases and can be moved [9].
Graph between Vickers hardness numbers with compaction pressure.
Solid-state sintering can happen by coarsening and grain growth.
(a) Ceramic grain growth and (b) Structure micro of ceramic composite.

The numbers along the horizontal and vertical axis correspond with the position in microns.
The interface crack length for the left grain is only 0.5 µm, which is much smaller than the interface crack length for the right grain, viz. 6.0 µm.
(a) Two α-Zn grains with similar crystal orientation.
(b) Two α-Zn grains with different crystal orientation, as indicated.
Acknowledgements This research was carried out under project number MC7.00075A in the framework of the strategic research program of the Netherlands Institute for Metals Research (www.nimr.nl).

We can see from surface of casting blank in picture 1 that, the grain is refined, zone of columnar crystal is reduced and equiaxed grain is enlarged.
From table 2 we can see that, when content of rare earth is 600ppm, the grain is refined obviously.
However, when content of rare earth exceeds a certain range, the grain is enlarged.
Table2 Comparison of the grain diameter Number of Sample Amount of rare earth added (PPm) Average Diameter of Grain (mm) Sample 1 0 0.165 Sample 2 70 0.078 Sample 3 84 0.062 Sample 4 112 0.071 Sample 5 140 0.090 Cu-Ag alloy casting blank without rare earth Cu-Ag alloy casting blank with rare earth Fig. 1: Macro-organization pictures of Cu-Ag alloy casting blank without rare earth and Cu-Ag alloy casting blank with rare earth 3.2.3 Effect of rare-earth addition on mechanical property and electrical conductivity of Cu-Ag alloy wire pole The reason why rare-earth element can enhance high-temperature plasticity of Cu alloy is mainly that, rare-earth element is a kind of active element which can react with low melting point impurity elements such as Pb, Bi, P and S in Cu alloy to produce high melting point compounds, which eliminates effect of harmful substances on grain boundary.
We can see from surface of casting blank in that the grain is refined, zone of columnar crystal is reduced and equiaxed grain is enlarged

The maximum number of layers in the composites was 21.
Transmission electron microscopy revealed that the sizes of the grain-subgrain clusters forming in the weld adjacent zones are about 100…400 nm.
Vortices forming in the process of explosive welding of thin steel plates At the sides of the wave crests the ferrite grains are strongly deformed.
Transmission electron microscopy showed that the sizes of the grain-subgrain clusters forming in the weld adjacent zones are about 100…400 nm (Fig. 5).
The number of twins in coarse grains reaches several dozens.

However, with the advancement of computer processing power, numerical modeling of diffusion phenomena has become more affordable, resulting in an increasing number of studies in this area.
They reported the initial grain size values and that no grain growth was observed during experiments.
The authors also measured the strain rate dependence on grain size, from which they calculated the inverse grain size exponent to be 2.3.
The authors report that the grain morphology was unaffected by creep, which is consistent with grain boundary sliding accommodated by diffusion.
Discussion A number of high temperature creep studies on perovskites have been reviewed.