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With the development, various kinds of fibers have been developed for microwave absorption, such as carbon fiber [1], [2]and[3],silicon carbide fiber [4] and[5], polycrystalline iron fiber [6]and[7] and their modified fibers[8],[9]and[10] because of their light mass, excellent mechanical properties and electromagnetic properties.
And obtain the good absorbing properties by optimizing fabric specifications.
Orthogonal experimental with three factors and three levels of the fabric specifications and was the test results of absorbing properties were shown in Tab.1.
Putting the measured value into Matlab program, the net surface figure and contour map of minimum reflectivity and bandwidth were simulated and shown in Fig.1: From the Fig. 1 we can see, when the core-spun yarn diameter was in 20 ~ 35μm and the total fabric density was in 6×104~7×104/100 cm2, the minimum reflectivity can below -20dB; When bandwidth over 3GHz, core-spun yarn diameter should be limitted in 25-30μm and total fabric density in 6.5×104/100 cm.Fig. 1 also revealed the interaction between core-spun yarn diameter and total fabric and the latter was the main factors affecting the minimum reflectance and bandwidth.
As the experimental results showed, the factors of gram weight, blending ratio and interlacing point can obviously effect the absorbing performances of the double composite fabrics.

Zhao has been conducted a series experimental study of sulfate attack on ordinary concrete with or without stress in conditions of long-term immersed in sodium solution, wet-dry cycles, carbonation and compound factors [3-8].
However, with the increasing use of machine-made sand as fine aggregate, the durability of concrete affected by machine-made sand is necessary to be studied [9, 10].
Their physical, chemical and mechanical properties are listed in Table 1 to Table 4.
Table 1 Physical and mechanical properties of cement Grade Fineness (%) Water content of standard density (%) Setting time (h:min) Compressive strength (MPa) Tensile strength (MPa) Initial Final 3d 28d 3d 28d 42.5 4.6 26.74 3:28 4:07 18.8 57.5 4.7 8.7 Table 2 Properties and chemical combinations of fly-ash (%) Fineness Ignition loss (%) Ratio of water demand (%) SO3 MgO SiO2 Fe2O3 Al2O3 CaO Na2O K2O 13.6 5.17 100 0.50 1.47 52.91 4.85 26.91 4.7 0.42 1.60 Table 3 Physical properties of machine-made sand Series (mm) Fineness modulus Apparent density (kg/m3) Bulk density (kg/m3) Closed volume density (kg/m3) Content of stone-powder (%) 0~4.75 3.5 2720 1475 1700 4.6 Table 4 Physical properties of coarse aggregate Series (mm) Apparent density (kg/m3) Bulk density (kg/m3) Crush index (%) Mud content (%) Closed volume density (kg/m3) Content of needles-silce and particular (%) 5~20 2740 1450 7.2 0.56 1630 11 Table 5 Mix proportions of concrete No.
The sulfate-ion content in the first layer does not reflect the real status of concrete affected by tensile stress levels due to the damages.

Experimental results suggested that temperature and humidity could individually reduce the mechanical properties of Hemp fibre.
Semi empirical and neural networks were used to predict the hygro-thermal effects on the mechanical properties under static tensile loading.
It was found that the lost in stiffness of Hemp fibre following immersion in water was identified as one of the major factors in the lost of tensile modulus and strength of polyester/hemp fibre composite [10].
It was claimed that besides the humidity, micro fibril angle could also affect the mechanical properties of Hemp fibre.
Prediction of tensile properties.

We can get the basic physical and mechanical performance parameters of the sample: the uniaxial compressive strength and elastic modulus and stress-strain curve, etc.
With reference to the coal industry standard of the artificially frozen soil physical and mechanical performance test (MT/T593.4 1996); 3.
Study on mechanical properties of frozen rocks The cretaceous strata frozen rocks stress-strain curve is the relationship curve of the vertical load (the axial stress σ) and vertical compression deformation ε.
As some of the soil samples contained sandwich, some test result laws were not obvious.The elastic modulus of rock samples had business with the soil properties, and stress-strain curves of the sample loading process, and many other factors. 
Experimental research on the mechanical parameters of frozen pipes under low temperature [J].

ZHOU et al[2] studied factors affecting cyclic loading which contain cyclic stress ratio, loading frequency and other factors.
The soil stratification and physic-mechanical properties is shown in table 1.
Table 1 Soil stratification and physic-mechanical properties Index Soil stratum w（%） γ(kN/m3) Ip Il C(kPa) φ(°) Es(MPa) fk(kPa) qsa(kPa) qpa(kPa) 1 undisturbed soil 2 Silty clay 27.1 18.8 15.8 0.343 31.3 17.7 5.0 120 16 4 Silty clay 21.1 19.5 13.3 0.333 29.7 14.1 10.0 200 20 6-1 Highly weathered limy siltstone 29.1 19.2 21.0 0.247 31.8 11.8 8.0 300 25 6-2 Strongly weathered limy siltstone 500 35 6-3 Intermediary weathered limy siltstone 1000 50 3000 Note: w is natural water content of soil; γ is natural unit weight of soil; Gs is specific gravity of soil; e is void ratio of soil; IP is plasticity index of soil; IL is liquidity index of soil; C is cohesive strength of soil; φ is internal frictional angle of soil; Es is modulus of compressibility of soil; fk is calculated ground bearing capacity; qsa is limit frictional resistance; qpa is ultimate tip resistance.

The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties.
The software, due to self centring properties, allows to simulate the process without the Guide rolls.
All the tools were simulated as rigid bodies and between the rolls and the workpiece a shear friction factor equal to 0.7 was set.
Therefore the different axial roll speed laws do not significantly affect the ring geometry produced.
The maximum Idle load seems to be not affected by the different Axial roll speed laws.

Sewage treatment plant process aeration or mechanical agitation , the sewage in a variety of microorganisms may send out into the air, the form of aerosol form toxic and harmful air pollutants. 2.2 weather’s characteristics of the formation formation factors of haze had three main aspects: one was the increase of the particle suspension, motor vehicle exhaust and smoke exhaust particle size in micron level that stays in the atmosphere; The second was horizontal direction in no wind.
Indirect effect refered that the change of aerosol concentration affected the characteristics of cloud (including optical properties, the cloud cover, cloud, etc.), increased the reflectivity of cloud to solar radiation or made cloud last longer, and even reduced rainfall.
The reaction mechanism was likely to be: oxygen freeed radicals in the lung; chemical factor and cytokine released.
Organic carbon in the haze would seriously affect human health.
The harmful components such as fine particulate matter and ozone identified and monitored , the source of the physical and chemical properties of particle emission diffused reaction and transformed between the various substances in the process of research.

Composite is a material made out of two diverse constituent materials each having distinctive physical and substance properties and this would make a last consolidated material with unexpected properties in comparison to that of parent constituents.
MMCs can offer fundamentally enhanced properties including durability; particular modulus, damping limit, and great wear opposition contrasted with original material.
Major factors affecting wear are sliding distance, load, speed, etc. and it is therefore important in tailoring the composite materials and come up with optimized material to get the best performance [10-14].
In this research, attempts have been made in producing hybrid Al-MMCs by liquid state processing and examine its mechanical properties.
Conclusions · Preparation of hybrid composites by liquid metallurgy technique was made with analyzing of mechanical properties.

It is assumed that the material properties of arches vary with the thickness direction as a power function.
Because of the superb properties of high strength and high temperature resistance, FGMs (functionally graded materials) are ideal materials for preparing structural elements used in aerospace, nuclear reactors and other high temperature environments.
The main factors affecting elastic buckling load may be load type, the geometrical shape or size, and boundary conditions of the arch.
Considering a circular arch of ceramic-metal FGM with rectangular cross-section, subjected to uniformly distributed radial follow load as shown in Fig. 3, the material and geometric properties of the arch are given as follows [16]: ,, =27.88 , =380,
The factors that affect buckling of FGM arches are discussed.

Temperature gradient determines the microstructure and mechanical properties of the SLM part, so studies about temperature fields are primarily important.
The temperature is one of the key parameters which define properties of matter, phase transitions, the rate of chemical reaction, microstructure of sintered material and mechanical properties of produced SLM object.
All properties of the material were temperature-dependent (Fig. 1).
Kruth, Determination of geometrical factors in layerwise laser melting using optical process monitoring, Opt.
Mills, Recommended values of thermophysical properties for selected commercial alloys.