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This paper introduces system dynamics (SD) model to build a dynamic global network model and analyzes the network structure, including link properties and feedback loops.
·In the subsystem network, each of elements is a subsystem affected by some factors.
ØPopulation subsystem’s main negative feedback loops This loop shows: The population growth diminishes the per-capital GDP, next boosts mechanical growth population, next boosts the population growth in turn. 2.3.2 The other three subsystems Other three subsystems are formed as the population subsystem.
The following equations can be obtained: (1) · : the number of planets to provide the resources we use and absorb our waste · : Ecological Footprint · : Biocapacity According to the system dynamics model, the factors affected earth’s health is mainly population, nonrenewable resources, industrial output and persistant pollution.So we use multiple linear regression[3] to analyze the relationship between factors by SPSS.

Our purpose is based on the existing construction technology, mechanical equipment; building materials and construction technology of comprehensive study, for the later of the continuous rigid frame bridge construction provide a certain amount of experience.
And flexibility of piers should be adapted to the temperature variation and concrete shrinkage, creep and braking force caused by factors such as the horizontal displacement.
Causes of the bridge construction control: Cantilever construction method is adopted to build the prestressed concrete continuous rigid frame bridge directly, faced with the problem of reinforced concrete is a kind of heterogeneous material, material properties is not stable, but also affected by factors such as temperature, humidity, time, and this kind of influence each other and there are differences, resulting in concrete pouring segment that would produce the different stress and displacement, the actual state of the bridge deviates from the value of the design.
At the top of the pier construction, the bridge has been basically completed, not affect the traffic, bridge construction is basically on a stage of the repeated, can make the construction personnel skilled construction technology, construction skills, thus ensuring the construction quality, construction process of the influence of the small on the surrounding environment.
Before pouring sequence by backward, from the web to promote among, layered casting, casting thickness remains at about 30 cm. 5.3 side span and closure period of construction, erection of temporary piers can use assembled components, which is set on the piers steel bearing beam, instead of a floor stand, can also adopt the way of the final closure for the side span and the approach span cantilever connection instead of floor stand. 5.4 closure segments in continuous steel structure bridge during construction is the most key link, determines the linear meets the requirements, the closure segments to factors such as shrinkage, creep of concrete at the cracking problem has a great influence.

In many applications the fatigue behavior is one of the most important factors which should be considered because the most parts of machines are susceptible to fatigue fractures.
Variations of these factors affect the KIC which expresses the fatigue behavior of ADI.
Optical and Mechanical Test.
The mechanical properties of austempered specimens at two temperatures of 320 and 400°C are compared in Table 2.
Mechanical properties of austempered specimens.

Introduction The increasing need to use the technological properties of materials with special reports are increasing use the thermal spray coatings [1].
The application of coatings is widely used in industry as a way to prevent wear of mechanical components [1].
It is among the different types of wear that affect the performance of different industrial processes.
The mechanical behavior was assessed via measures of micro-indentation hardness, using a microhardness tester (Futuretech – Model.
This resulted in greater mass loss, although this material offers greater mechanical strength.

A modified CP constitutive model, which considers the backstress evolution, is employed to describe the mechanical behaviour of AA7075 under cyclic loading.
The factors affecting local deformations are complicated, including the inhomogeneity of material, crystallographic orientation, grain morphology, particles, geometry of specimen, elastic and plastic anisotropy, loading conditions.
Recently, Li et al. [10] investigated the local deformation of polycrystalline aluminium alloy (AA) 2024 under nanoindentation through CPFE model which includes the effect of grain morphology, and found that the pile-up pattern and local stress in the indentation zone strongly depends on grain properties.
No particular treatment is applied to the grain boundaries, thus the grain boundary effect is entirely caused by the different crystalline properties of neighbouring grains.
Morel, Micro-mechanical modelling of high cycle fatigue behaviour of metals under multiaxial loads, Mech.

However, due to inaccuracy of experimental data caused by uncertain factor, the limitation of space and experimental expense, numerical simulation is accepted as an effective and efficient mehtod in the research of wind-blown sand movement.
The aerodynamic drag FD: The forces acting on a sand particle moving in air flow, at the same time, air flow is also affected by the force of particle.
Fig.2 The smoothed length and support domain The Key Factor of SPH Method.
By observation over these results, it can be concluded: (1) The sand particles at the top of the sand bed are remarkedly affected by the air flow speed, and it will turn into the state of lifting-off motion in a short period of time.
(2) The sand particles in the middle layer of sand bed is not only affected by the air flow, but also by the extrusion and haunch-up actions from its upper and lower sand particles, respectively.

The interaction between the fiber and the matrix is the fundamental property that affects the performance of discrete fiber composite cement past.
In this case, the fibers behave as non-active inclusion leading to only marginal improvement in the mechanical properties [1].
Table 2 Experimental tested results Specimen Factors Compression strength (Mpa) Increase ratio density (kg/cm2) Fiber length fiber ratio C : S W:C Group one 1 20 1.5 1:3 0.47 27.1 15.3 2030 2 35 1.5 1:3 0.47 27.4 16.5 2240 3 50 1.5 1:3 0.47 24 2.0 2180 4 20 3.0 1:3 0.47 29.45 25.3 2200 5 35 3.0 1:3 0.47 28.2 20 2270 6 50 3.0 1:3 0.47 20 -15 21750 7 20 4.5 1:3 0.47 17.2 -27 2070 8 35 4.5 1:3 0.47 21.1 -10.2 2175 9 50 4.5 1:3 0.47 17.96 -23.6 2195 Group two 10 20 1.5 1:2 0.47 22.04 13.02 2200 11 35 1.5 1:2 0.47 22.00 12.8 2300 12 50 1.5 1:2 0.47 20.45 4.8 2285 13 20 3.0 1:2 0.47 25.0 35.9 2280 14 35 3.0 1:2 0.47 25.8 32.3 2240 15 50 3.0 1:2 0.47 21.2 8.25 2150 16 20 4.5 1:2 0.47 21.0 7.7 2184 17 50 4.5 1:2 0.47 20.7 6.1 2180 Group three 18 20 1.5 1:4 0.47 16.02 9.70 2030 19 35 1.5 1:4 0.47 16 8.6 2050 20 50 1.5 1:4 0.47 16.25 11.30 2140 21 20 3.0 1:4 0.47 11.5 -21.5 2050 22 35 3.0 1:4 0.47 10.1 -30.8 2000 23 45 3.0 1:4 0.47 9.5 -35.5 1850 24 20 4.5 1:4 0.47 6.75 -53.7 1835 25 50 4.5
S.: Mechanical properties of steel fiber reinforced rapid-set materials.
:Mechanical properties of glass and steel fiber reinforced mortar,” ACI Journal. – V.73, № 10. – (1976) P. 50 – 53.

So basically the speed of the process has three influencing factors: - geometrical complexity of parts in the build job that influences the yield of the working space in part’s direct vicinity (“density” of a part), - yield of the whole working space of the AM system (“density” and numbers of parts in the job), - the technology used in the specific AM systems.
This paper will focus on the effect of the laser speed in the SLS process and will use the first 2 factors to determine the results.
When increasing the laser speed with a factor 2, the average manufacturing speed will increase by a factor lower than 2.
The 2k factorial design principle on which this experiment is based, requires that the test needs to be performed at combinations of both high and low levels of the influential factors [4].
Berce, et al., Research on improving the mechanical properties of the SLS metal parts, Proceedings of the 19th International DAAAM Symposium, (2008) 1003-1004 [4] Montgomery, D.C.

The magnitude of the electrical conductivity of host oxides themselves is determined by the different factors.
Compared to materials based on zirconia, CeO2-based materials have poorer mechanical properties.
It is reported that Gd2TiO7 is a better sintering aid than pure TiO2 in terms of lowering the sintering temperature without adversely affecting other properties [264-265].
As a result, these processes may become the limiting factors for the cell performance.
Meriani, Mechanical properties in the ceria-zirconia system, J.

On the other hand, changing the size and structure of two-dimensional materials result to nanostructures with new and unique properties.
These nanoallotropes consist mainly of sp2 carbon atoms positioned in a hexagonal network, meaning that this common structure leads to some common properties e.g., similar levels in optoelectronic properties, mechanical strength, and chemical reactivity.
In contrast, significant differences in sizes and shapes attribute different morphological properties e.g., porosity, specific surface area, etc.[8] Among the carbon nanoallotropes, graphene nanoscrolls (morphologically similar to multiwalled nanotubes) and quantum dots, present a unique set of properties mainly due to their open-ended morphology and exceptional optical properties, respectively.
The scrolling tendency of germanane nanosheets is probably based on similar factors reported in the literature for graphene nanoscrolls, including specific solvents, sonication time, power etc.[9,13] Summary Here we present the synthesis of siloxane and germanane nanosheets and their conversion through an ultrasonication approach into nanodots and nanoscrolls, respectively.
The production of 0D and 1D nanostructures from these layered materials can result to novel nanostructures with unique properties.