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As the solid granule medium is single and independent, its mechanical characteristics can be summarized as loose and dynamic, the former refers to the physical features, grain size and disperse of the shape, while the latter means the transient and fluctuation movement with collision, particle cohesion, clump abruption and fracture.
Introduction of DEM The DEM was first proposed by Cundall, etc. in the late 70s of 20th century [7], whose basic idea is simplifying the particle group into a collection of a finite number of discrete components with certain shape and mass, for the particle system, a single particle (circle disk or ball) is treated as an element, and the group behavior of granules is described according to the interaction forces between elements and Newton's laws of motion.
After loading, the force chains gradually get dense, with the formation of a number of short and thick strong chains, the external load are transmitted.

Introduction In Al-Si hypoeutectic alloys, trace level additions of Na or Sr refines the eutectic Al grains and the coarse plates of eutectic Si to a fine morphology [1-3].
The number density at each alloy temperature was evaluated based on the molar weight and molar volume data obtained from the FactSage thermodynamic database software*.
(1) In Eq. 1, νo is a constant calculated from the Lindemann’s melting point atomic frequency formula modified for metals by Iida et al [16], n is the number density, xAl, xSI are the concentrations of Al and Si, respectively, P(Al) and P(Si) are the proportions of vibrating atoms of Al and Si in the liquid, and a, b and c are values of r (radial distance form a given centre atom) corresponding to the first minimum of the partial pair correlation functions gAl-Al(r) , gSi-Si(r) ard gAl-Si(r).

To reduce the unnecessary number of elements and to guarantee the calculation is performable, element type transition in the space must be carried out.
The total elements amount of ChaHanWuSu CFRD is 18,981 and the total nodes number is 20,443.
Constitutive models 3.1 Coarse–grained material constitutive model Nonlinear elastic Duncan-Chang E-B model [1] which widely used in China is adopted to simulate the behavior of Rockfill materials.

SEM surface of the second layer of MgB2 superconducting film The SEM photo of the surface of the second layer MgB2 film was shown in figure 4, we could see from this photo that the MgB2 crystalline grains were dense and well-distributed expert a few hollows, according to the experiment we found that the hollows may come of the dust pollutition of the system.
State invention patent: Date of authorization proclamation: September 10th, 2003; Patent number: ZL 01 1 28831.0; International Patent Classification number C23C 16/38

(3) Do the natural grain sieve analysis, and then make the evaluation particle size distribution and draw the grading curve
(3) Increase the number of layers.
If increasing the number of layers, lighting effect is forced to consider for the surrounding residents.

Simulation results and discussion Fig4 Clock offset performance of Collaborative synchronous Figure 4,=1 through computer simulation synchronous clock deviation of maximum likelihood estimation MSE and CRLB curve.Figure 4 shows the synchronization node on the interaction between the news the more the number, the higher the synchronization accuracy.
But for the purposes of the wireless sensor network, the more the number of messages exchanged between the node pair, it consumes more energy.
Fine-grained network time synchronization using reference broadcasts[C].

PTRACE_TRACEME tells the kernel that the process is being traced PTRACE_PEEKUSER can read the system call number which saved the original contents of the exam register , etc.
The steps are following: ① PTRACE_ATTACH: parent can trace an existing process ②PTRACE_GETREGS: get register value, including system call numbers. ③PTRACE_PEEKDATA, PTRACE_POKEDATA: a word from location data is copied to the child's memory location adder.
For example, some experienced users would be able to use to gain fine-grained access control to input specific PID.

For example, if the abrasive tool wears by a slow glazing of the grains, the machining forces will rise and may lead to various problems such as poor size-holding, vibrations, and poor surface texture.
This is because that, the surface roughness is directly to the particle number Ng and the particle shape which participated in the grinding process.
The particle number Ng is increased with the increase of contact pressure under lower contact pressure, so the amount of grinding surface roughness decreases uniformly. 

Dry Shrinkage Table5 Dry shrinkage of high performance pavement concrete Num C kg/m3 CUFA kg/m3 CUFA % SL mm Dry shrinkage（10-6） 3d 7d 14d 28d 60d 90d 180d 1 320 80 20 45 90 180 250 290 420 460 474 2 280 120 30 35 80 150 190 230 362 402 432 3 240 160 40 40 75 146 184 241 382 412 429 Figure2 The influence of CUFA on drying shrinkage A large number of research data [5] show that ultra-fine fly ash can well restrain the dry shrinkage of concrete for its excellent water reduction, close-grained filling, and micro-aggregate effect.
Flat Test Table6 Record of the cracks Num Record of the cracks 8h 10h 12h 23h 25h 26h 1 Crack free Crack free Crack free Minute crack/two Minute crack/two Minute crack/two 2 Crack free Crack free Crack free Minute crack/one Minute crack/one Minute crack/one 3 Crack free Crack free Crack free Crack free Crack free Crack free Table7 The influence of CUFA on cracking performance Num Initial cracking time Average area of cracks（mm2） Fracture number（/m2 ） Crack area （mm2/ m2 ） Cracking grade fcu,28d (MPa) 1 23h 5 5.56 27.8 I 54.1 2 23h 2 2.78 5.56 I 55.4 3 Crack free Crack free Crack free Crack free I 52.2 The results in Table 6 and Table 7 show that high performance pavement concrete has better crack resistance.

Besides, the movement kinematics is determined by a number of external factors, such as: type of the movement, the load friction, the shape of the cooperating surfaces, the surface roughness, the type of lubricant, and finally the type of material association.
The grinding of metallic specimens was performed with papers Nos. 200 to 2400, and final polishing was made with the diamond suspension of 3 and 1 µm grain size.
Comparison of the circumferential groove depth for experimental samples Friction pair Number of sample Material Circumferential groove depth d [µm] Average circumferential groove depth dav[µm] Ti6Al4V/UHMW-PE 1 Ti6Al4V -22.56 - 2 8.82 13.42 3 18.02 1 UHMW-PE 14.14 22.25 2 35.26 3 17.34 Ti13Nb13Zr/UHMW-PE 1 Ti13Nb13Zr -12.40 - 2 0.34 7.43 3 14.51 1 UHMW-PE 21.53 26.38 2 28.71 3 28.91 The negative values obsrved for both alloys are an evidence of deepening of circumferential grooves as a result of migration of wear products into the grooves and their further degradation.