Advanced Materials Research Vols. 150-151

Abstract: Electromagnetic shielding clothes for protecting human exposure from harmful radio waves have been commercialized. However, most research has so far focused on the fabrics. In this paper, based on the orthogonal experiment method, design the structure of the electromagnetic shielding clothes, and conduct the performance test. Through direct and variance analysis, find out the significance degree of the structure factors, and then get the best level combination of the factors, thus provide a theory basis for optimization structure design of electromagnetic shielding clothes.

Abstract: Reactive Powder Concrete (RPC) is a new kind of building material with high strength and other good performance. The combination of RPC and steel tube will compensate the brittleness of RPC and enhance the stability of steel tube, and the loading capacity of the RPC filled steel tube will be improved. Five RPC filled steel tube columns are designed and tested to obtain the ultimate load bearing capacity, the deformation and the strain information. During the loading process, the concrete and the steel tube of the RPC filled steel tube columns are loaded simultaneously. The loading results show that the deformation of the RPC filled steel tube columns are mainly in elastic phase before the loading capacity is up to the ultimate value. The test load decreases to be 80%~90% of the ultimate loading value and then it changes to be smooth. The failure mode of the RPC filled steel tube columns is ductile. The test loading capacity is compared with the formula from the reference. The tested ultimate load bearing capacity of the steam cured RPC filled steel tube columns is higher than the calculated value. The calculated value is safe for the engineering application. The study is useful for the research and application of RPC filled steel tube column.

Abstract: Trisiloxane surfactants can significantly enhance the biological activity of pesticides, in order to optimize of synthesis technology,in this paper,there was no gas protection,cleared trisiloxane surfactants optimization conditions by took the sample at different reaction time and measured degree of reaction degree by chemical titration method,infrared spectroscopy characterized,deteminated surface tension and controled weeds. This technology is more convenient than existent technology.The best reaction conditions:catalyst was 10mg/L,reaction temperature was 80 ,material ratio was 1:1.2, reaction time was 5 hours,the degree of their response would totally up to 93.83%.The surface tension compared with Silwet408 no significant difference to water and liquid. Different reaction degree trisiloxane surfactant could increased weed control of fomesafen differently.When added reaction degree 93% trisiloxane surfactant,dosage 1‰((v/v),enhanced observing 28.5% and fresh weight 29.5% than 252g ai/hm-2 only treated.Thus,this method could be used in production of trisiloxane surfactants.

Abstract: The natural villous bamboo fiber is a kind of debris that product in the process of natural bamboo fiber production. Using villous bamboo fiber to product MDF, bamboo resources can be fully used, and this can perfect the natural bamboo fiber production chain. For determining the optimum technological parameters of villous bamboo fiber MDF, the relationship between the technological parameters and the performances are discussed in this paper. By comparing the GB/T11718-1999 MDF standards, we found the villous bamboo fiber MDF with optimum technological parameters that cost is low, performance is moderate. It’s in line with the requirements of large-scale production.

Abstract: The composite DLC films doped with different content of Cu, Ti unitary and binary metal have been deposited on stainless steel and silicon substrate using DC-magnetic separation and pulse cathode double-excitation source plasma arc deposition technique. Structural and mechanical properties of the films were investigated by Raman spectroscopy, Atomic Force Microscope, micro-sclerometer and surface profilometer. The results indicated that the hardness and internal stress of Cu-DLC films decrease upon incremental content of copper from 0 to15 at.%. More attractively, a simultaneous improvement of the hardness (31GPa) as well as the release of the internal stress (up to 55%) can be achievable for samples with the relative atomic percentages of Ti and Cu contents of 43.6% and 1.56% respectively.

Abstract: nylon 11 nanocomposites with different montmorillonite loadings were successfully prepared by melt compounding. XRD and TEM show the exfoliated nanocomposites are formed at low montmorillonite concentration(less than 2wt%) and the intercalated nanocomposites are obtained at higher montmorillonite contents. TGA shows that the thermal stability of the nanocomposites is improved by 27°C when the montmorillonite content is only 2wt%. Mechanical testing shows that the Izod impact strength of all nanocomposites are higher than that of the neat nylon 11, but the tensile strength of the nanocomposites decrease at low nanofiller concentrations (less than 8wt%) and than increased, when the montmorillonite content is 10wt% ,the tensile strength of the nanocomposite is 5% improved than neat nylon 11. This is may be due to the strong interaction between the nylon 11 matrix and the montmorillonite interface.

Abstract: Ultra-high toughness cementitious composite (UHTCC) is a PVA fiber reinforced cementitious composite. Tensile strain hardening behavior with ultimate tensile strain of more 3% under direct tensile loading is one of its important characteristics. In the current article, nine simply-supported reinforced UHTCC beams were subjected to four-point bending loading to experimentally investigate the influence of ductile deformation behavior of UHTCC on ductility capacity of reinforced structural members. Ductility index is determined by adopting three different parameters, i.e., deformation capacity, energy dissipation capacity as well as curvature capacity. The effect of longitudinal tensile reinforcement ratios on the variation of ductility in UHTCC reinforced beams was examined. It was found from the experimental results that the combination of ductile matrix (UHTCC) and steel bar prevents from occurrence of localized cracks in pure bending zone, showing high damage tolerance and ductile failure behavior. The results also show that as longitudinal tensile reinforcement ratio increases, deformation ductility and curvature ductility both exponentially decrease while a small reduction is demonstrated for energy ductility at ultimate failure.

Abstract: Compressive buckling of laminate plates with a delamination are simulated using ABAQUS 6.8 software. Effects of sizes, positions, asymmetric and shapes of delamination on the compressive buckling are investigated without the consideration of delamination growth and contact. The results indicate the sizes, positions, asymmetric and shapes of delamination have an important influence on compressive buckling.

Abstract: The steady thermal stress distributions and effect factors in a ceramic/FGM/metal composite EFBC plate considered constant material properties under convective heat transfer boundary were investigated by the FEM and the Sinpson method. From numerical calculation, when , T0=300K, Ta=400K and Tb=1 400K, the stress distributions in the plate were obtained. The results are as follows. With the increase of the FGM layer thickness, the stress distribution in the composite plate is more reasonable. Compared with M=0.2, when M=5, the compressive stress on the ceramic surface reduces by 10.2%, and the tensile stress on the metal surface reduces by 21.7%. With the increase of A, the variations of thermal stress curves become big. Compared with A=0, when A=3.99, the tensile stress on the metal surface increases by 198.0%, and the maximum compressive stress on the surface of ceramics increases by 66.0%. Compared with the mutation of thermal stress at the cohesive interface of ceramic / metal two-layered composite plate, the thermal stress of ceramic/FGM/metal composite plate is very gentle. Compared with , when , the maximum tensile stress on the metal surface increases 1.44 times, and the maximum compressive stress on the surface of ceramics increases 1.50 times. The results provide the foundations of theoretical calculation for the design and application of the composite plate.

Abstract: In order to study various factor affecting durability of steel fiber reinforced concrete (SFRC), basic experimental research that combine the action of freezing-thawing cycles and deicing salt to SFRC was conducted. In the experiment, the volume fraction of steel fiber and number of freeze-thaw circulation are taken as variable parameter. Based on the different numbers of freeze-thaw circulation, weight losing of SFRC, splitting strength and the dynamic modulus of elasticity were measured. Furthermore, the reinforced mechanism of the SFRC under the action of freeze-thaw was analysed. The test results show that after adding a certain amount of steel fiber to the concrete, cracks in concrete at early stage are effectively prevented and the permeability of concrete is obviously reduced, thus the durability of concrete is improved. The reinforced actions of steel fiber on splitting strength of concrete are notable and the influence of steel fiber volume fraction on the frost-resisting property is obvious. On the contrary, the negative effects of steel fiber with high volume fraction on the splitting strength of concrete exist. The best performance of SFRC can be got when the steel fiber quantity is 1.5%.