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Van der Pauw correction factor were calculated based on the results of the two-times voltage measurement.
However, his study focused on the determination of geometrical correction factors for the general case of an in-line four-point probe positioned on a thin circular sample.
There is reason to believe that the better performance of the designed measurement system is mainly attributed to the superior properties of dual-measurement with four-point probe method.
Lee, A New Micro-Four-Point Probe Design for Various Applications, IEEE 22nd International Conference on Micro Electro Mechanical Systems 2009 84-87
Perloff, Four-Point Probe Correction Factors for Use in Measuring Large Diameter Doped Semiconductor Wafers, Journal of the Electrochemical Society: Solid-State Science and Technology (1976) 1745-1748

Research on the Impact of Needle Valve Orifice Chamfering on the Performance Based on Fluent Yong Tao a*, Hongxia Cai b, Yujie Bai c and Tingting Yu d Shanghai Key Laboratory of Mechanical Automation and Robotics, School of Mechatronics Engineering and Automation, Shanghai University, Shanghai, China ataoyong@shu.edu.cn, bhxcai@staff.shu.edu.cn, cbaiyujie@shu.edu.cn, dyutingting499@163.com Keywords: Needle Valve; Flow Coefficient; Computational Fluid Dynamics; Grinding.
Needle valve as one of the most important components in injection system, it will directly affect the performance of the injection system0.
When r / D is about 0.3 to 0.4, that is, when the improvement of orifice chamfering on orifice flow coefficient closes to stable, the impact of cavitation on jetting property is minimal.
[2] J.D.Yu, X.L.Miao.The research of nozzle flowcoefficient factor and injection characteristics [J].Modern Vehicle Power, pp.19-23, August 2007
Solid-liquid two-phase flow model and pressure characteristics simulation of abrasive flow machining [J].Chinese Mechanical Engineering, pp.17-19, April 2008

Introduction Hydraulic cylinder is the hydraulic actuator which changes hydraulic energy into reciprocating motion or rotational motion mechanical energy.
Therefore, the quality of raw materials and processing directly affect hydraulic cylinder’s qualification rate, lifetime and reliability.
Through the above analysis about the frequency influence to ultrasonic detection and the different frequency probes practical testing experiments of hydraulic cylinder, observed in about 5MHz frequency, the echo of cylinder barrel and the details of defect echo performs very well, so comprehensive consider all aspects of the factors, we choice the frequency is 5MHz.
From the point of view of sound delivery, the couplant should have following properties: 1.
Comprehensive consider all factors, we select water as the couplant in the process of hydraulic cylinder ultrasonic flaw detection.

In addition, many plain reservoirs are of shallow water storage, water pollution, which not only lead the poor economic performance, the serious problem of salinization, but also adverse impact to the environment and affect the efficiency of the use of plain reservoirs seriously.
The physical and mechanical properties of field test area’s foundation soil is illustrated in Tab.1[5-6].
Tab.1 Values of mechanical parameters Soil class Thickness（m） ρ（kg/m3） Es（MPa） c（kPa） φ（°） Old dam sandy loam 2 / 4 2130 6.696 20.8 10 New dam sandy loam 5 1700 3.912 21.0 12 Foundation sandy loam 3 1960 4.93 21.0 11 silt 7 1970 10.65 25.0 10 clay 3 1880 3.92 18.2 19 sandy loam 2 1990 4.83 19.4 18 clay 3 2040 4.62 18.1 16.6 2 Vertical expansion modes In the view of the project present state (2 meters height, 3.5 meters water storage depth, 1:3 slope gradient) and geological information, two vertical expansion modes had been put forward.
Tab.2 Vertical expansion modes Vertical expanding modes Height(m) Water storage depth(m) Expanding capacity Present 5 3.5 Δh(m) Expanding percent(%) ①：+2m 7 4.5 1 28.6% ②：+4m 9 6 2.5 71.2% 3 Mechanical effects analysis of different treatments 3.1 Numerical computational model At present, the dam impounds 3.5 meters depth water and the dam foundation do not take any anti-seepage control measures.
But the bottom of new dam requires special treatment to prevent the dam from subsidence crack. 4 Dam slope stability analysis Tab.3 Minimum safety factors under different methods Mode I II Minimum safety factors Bishop method Swedish circle method Bishop method Swedish circle method Project (I) Upstream 3.967 3.777 3.314 3.140 Downstream 2.026 1.822 1.816 1.662 Project (II) Upstream 3.404 3.157 3.278 3.070 Downstream 2.025 1.821 1.818 1.652 By analyzing the results in Tab.3, the dam slope stability in two ways of heightening dam is of litter difference and can both satisfy the stability requirement.

All those aspects consequently enhance the mechanical properties of the weld metal and the joint itself.
Digital voltage and current signals recorded were used for further statistical analysis with number of factors and indicators commonly utilizing for signals analyzes.
Carrer factor [8] as defined as the ratio between the minimum of current registered and the mean current value, calculated as ratio (n) of the east current value (occurred directly after short circuit) to the mean of welding current: The Carrer criterion (n) states that higher value of factor corresponds with better welding properties.
Sharma, Process stability evaluation of basic coated MMAW electrodes, using statistical analysis, mechanical properties and hydrogen content, Journal of Production Engineering, Institution of Engineers (India) (2006), 86
Cegielski, Study of technological properties of inverter welding power supplies, Welding Overview (2006), 9-10 (in Polish)

In the event of an accident, the spot welded joints could fail by different mechanisms including ductile tearing of the heat affected zone and base metal under slow strain rates to rapid shearing across the fusion zone/ weld nugget at high strain rates.
Some studies have attributed the inaccuracy in the simulation results to poor representation of the mechanical behavior and failure process in spot-welded joints [5,6].
Local variation of material properties and hardening characteristics of the fusion zone and HAZ is approximated based on the hardness profile.
Stress triaxiality could affect the failure process either through a constrained plastic deformation with increasing stress leading to cleavage fracture or by voids nucleation, growth and coalescence under local straining resulting in the anticipated ductile failure.
This is likely due to mismatch of the stiffness of adjacent regions and the inherent geometrical stress concentration factor.

Fig.2 Planetary gear mechanism of shearer cutting department 1 sun gear;2 planetary gear;3 planet carrier;4 ring gear Objective function.Low coal loading efficiency of shearer drum is a key factor that restrains the development of thin seam shearer,and the volume of planetary gear mechanism is directly related to the coal loading efficiency of shearer drum.In the design of shearer cutting department,the smallest volume of planetary gear mechanism is required,and the main parameters that affect the volume are the parameters of sun gear and planetary gears.
Pre-treatment.The pre-treatment of finite element analysis mainly contains material properties definition,unit selection,mesh,loads.In order to reduce the amount of computer calculation, the paper carried out FEA for 1/4 model.
Contact stress cloud of planetary gear and ring gear was shown in Fig.9.Maximum stress occured at the tooth root was 103.5MPa, and the value difference was small compared with traditional method.The safety factor checked was 8(Allowable stress/Maximum stress) that could meet the requirements of mining machinery design safety factor.
The safety factor checked was 8 that could meet the requirements of mining machinery design safety factor,but there was a certain surplus amount of safety factor for improving and refining the design of Planetary gear mechanism.
References [1] Chuliang Yan,Fangfei Yang:New Technology of Mechanical Digital Design.

The use of this material for safety applications requires the identification of the mechanical properties of these cellular materials under different kind of loading and in a large range of strain rates.
The properties of these components are resumed in table 2.
Since one wants to establish response surfaces (for each response E, and ) as a function of the three parameters D, e and , the estimation of the quadratic model can be obtained using a 3 factors Box-Benkhen Design.
Brechet, Quasistatic mechanical behaviour of stainless steel hollow balloon foam: Macroscopic properties and damage mechanisms followed by X-ray tomography, Materials Letters, Volume 63, Issues 13-14, 31 May 2009, Pages 1113-1116, ISSN 0167-577X [2] S.
B., Uniaxial tensile elastic properties of a regular stacking of brazed hollow balloons, Scripta Materialia, 2003, 48, 1617-1623 [3] H.B.

Thus, mechanical and retentive properties of the cold pressed metal matrix mainly depend on the sintering conditions, which affect the matrix microstructure.
It is stated, that metal matrix is characterised by good retentive properties when holds diamond crystals firmly and keeps them exposed for maximum cutting efficiency.
When matrix contains high affinity element(s) for carbon, e.g. iron, than mechanical bonding is supported by metal-carbon (diamond) chemical reaction [1,2].
These allotropic phases are characterised by different properties: the phase ε is much more brittle and harder then phase α [3].
Then, it is obvious that cobalt's properties depend on its phase composition.

Measures factor adopted is as followed.
Where n is resource number, m resource’s property number.
These properties contain several main data of manufacturing service such as business function, business process, and quality of service and so on. 500 different particle size of Req requests are randomly generated.
In the future, the further research on performance evaluation factors’ selection and perfecting evaluation system will be done.
China Mechanical Engineering, 2012, 23 (15):1818-1824