Applied Mechanics and Materials Vol. 508

Abstract: In early research based on the study of gypsum, slag and other cotton stalk fiber composite of wall, by mixing EPS beads developed a lightweight, insulated, has a certain strength of new wall multifunctional composites. The material use EPS as insulation particles aggregate, slag as aggregate, cement and gypsum as matrix,through mixed with straw fibers of crushed cotton to solve inorganic and organic materials interface bond strength is low and EPS particles floating problems, In order to trial a kind of good performance of the wall material.

Abstract: High-strength steels are usually microalloyed with niobium (Nb), titanium (Ti) and vanadium (V), individually or in combination. The reheating temperature during austenization has a significant influence on the precipitation of microalloyed steels. The purpose of the study is to investigate the effect of reheating temperature on precipitates of microalloying elements. The research results show that reheating temperature should be high enough to ensure the dissolution of carbide and nitride precipitates in order to improve the precipitation strengthening of microalloying elements during rolling and cooling. The results provide the theoretical reference for the determination of reheating technology of microalloyed steels.

Abstract: Microstructure and precipitation of a Ti-Nb microalloyed high-strength steel were studied. The objective of the study is to examine the factors affecting yield strength and the effect of processing temperatures on microstructure and precipitation. The research results indicate that the dominant factors responsible for yield strength are fine ferrite grains and fine-scale carbonitride precipitatates, which are affected by processing temperatures. The influence of reheating temperature on precipitates was analyzed. Moreover, the optimum reheating temperatures is suggested for Ti-Nb microalloyed high-strength steel.

Abstract: The influence of grain refiner on the microstructure and mechanical properties of pure aluminum was investigated by separate and combined addition trace ScZr elements. The results show that the grain refinement effect of 0.2%Zr added alone is better than that of 0.2%Sc, each of them separate addition can make the strength and hardness of alloys increased obviously, and the decrease of the ductility is not remarkable, but the hardness increase of the alloy with 0.2%Sc is more significant than 0.2%Zr because of the strongly solid solution strengthening of Sc. While, the combined addition of 0.2%Sc and 0.2%Zr possesses the most excellent grain refining effect and change the growth morphology from columnar grains to equiaxed ones, the average grain size of the alloy is dropped to only about 100μm, and the strength, plastic and hardness of the alloy meet the reasonable matching, which is largely attributed to the effectively reduce of the Al-Sc eutectic point and the formation of Al₃(Sc, Zr) composite particles, These Al₃(Sc, Zr) particles can not only keep all the beneficial effect of A1₃Sc but can act as extremely effective nucleation sites of α (Al) and cause strongly fine-grain strengthening effect.

Abstract: seismic wavess energy and frequency will attenuate with its dissemination is one of the important seismic waves dynamic characteristics, and the most influential factors including the frequency, oil and gas saturation and porosity, so we can forecast the oil and gas according to the attenuation characteristics of the wavlet. The article extracted and analysised the attenuation properties of two different time seismic, and it could be seen that the remaining oil should be distributed in the southwest. So the result had a certain guiding significance to the exploration and development of the work area.

Abstract: An efficient near-infrared (NIR) quantum cutting (QC) nanophospors with Ce³⁺, Yb³⁺ co-doped in YF₃ had been prepared by hydrothermal method and characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), photoluminescence spectra and decay dynamics. The obtained nanorods were uniform and monodisperse. Under the excitation of 5d level of Ce³⁺, an intense NIR emission at 900 1100 nm was observed which match to the energy of Si band gap of Si - based solar cells. In the Ce³⁺, Yb³⁺ codoped YF₃, the lifetime of Ce³⁺ decreases and the quantum efficiency (QE) increases with increasing Yb³⁺ concentration.

Abstract: 30CrMnSiA steel is welded by CO₂ shielded arc welding with H08Mn2SiA and Ok Aristorod 12.5 welding wire respectively. The effect of welding compositions on the microstructure and mechanical properties of welded joint are studied. The results show that using Ok Aristorod 12.5 for welding, the microstructures of weld metal are mainly composed of acicular ferrite, proeutectoid ferrite and pearlite, the tensile strength of the welded joint is poor. When using H08Mn2SiA for welding, the microstructures of weld metal are mainly composed of fine grain ferrite and acicular ferrite, the acicular ferrite is refined and the content of acicular ferrite is increased, so the tensile strength of the welded joint is improved. Using these two welding wires are welded, the joints both have excellent bending properties.

Abstract: Pyrolysis is a new technology for scrap tires treatment and reuse. NATPC (non-activated tire-based pyrolytic char), the solid products from waste tire pyrolysis without subsequent activation procedure, was used in this paper to determine its potential ability as an adsorbent. The adsorption performance to Methylene Blue (MB) by NATPC was analyzed. Based on Uniform Design theory, the influence of pyrolysis parameters, temperature, heating rate, heating time and particle size were discussed. The adsorption of MB onto NATPC was conducted under different contact time, adsorbent dosage, MB concentration, pH and temperature. Langmuir and Freundlich adsorption isotherm models were applied and the corresponding sorption constants were evaluated. The maximum amount of MB adsorbed was 53.41mg·g^-1 at 20°C, which indicated NATPC can be used as an excellent adsorbent with good efficiency, simple manufacture and low cost.

Abstract: The desalination effect of two kinds of nanofiltration membrane, NF-1812-270 and NF-1812, were compared. Under the conditions of different pressure, made the comparison of the quotas between two different nanometer filtration membranes, including membrane flux, ash content, retention rate of chlorine, conductivity. The test results showed that the effect of desalination of NF-1812 nanofiltration membrane was better than the effect of desalination NF-1812-270 nanofiltration membrane.