Abstract: The morphology and growth mechanism of carbon nanotubes(CNTs) and carbon nanospheres (CNSs) produced by in-situ CVD method on different substrates were investigated using scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) technology. The experimental results show that the growth of carbon-nano-material has great substrate independence during in-situ CVD process. At the same reaction conditions, CNTs with diameters of 60-140nm and CNSs with diameters of 150-450nm were synthesized on the 1K carbon cloth and graphite paper substrate, respectively. Based on the experimental results, a probable growth mechanism was presented for different carbon substrates. The explanation for the formation process is the difference of the concentration gradient and growth rate in the catalyst.
Abstract: To research the strength of composite material barrels, based on the CDM theory, an energy-based stiffness degradation method is proposed to predict the progressive failure properties of steel- fiberglass/ epoxy composite laminated barrels. Three failure modes of fiberglass/ epoxy composites, including fiber breakage, matrix cracking and fiber/matrix interface shear failure are considered in the present model. A 3D finite element technique including the multiframe restart analysis is employed to conduct the progressive failure analysis. The results indicate that the mode considering the stiffness degradation and progressive failure of the material is more reasonable on researching the strength of composite material barrels. The strength of composite material barrels in this paper is influenced by the fiber strength mainly.
Abstract: Using finite element method, we solve the heat conduction equation. In our calculation, we use 0.02 and 0.052 °C/year as temperature rising rate (Gt) in order to get the change of gas hydrate layer of Qinghai-Tibet Plateau (QTP) in global warming situation. Our calculation’s major results are as follows: Our calculation demonstrates the gas hydrate layer’s surface temperature is one of the major factors which influence the thickness of gas hydrate layer (TGH). When Gt=0.02 and 0.052°C/year, the changes of TGH are almost same. The lower the ground surface temperature (GST), the more change of TGH. Therefore we need to monitor the Qiangtang plateau which has low surface temperature and good organic material.
Abstract: This article is taking 5.5"special thread petroleum casing-pipe as example, using nonlinear technology of Ansys FEA software to analyze characteristics of threading up and unload of the petroleum casing-pipe. The result of FEA is conformed to the experiment. It provides strong help for the enterprises using research data to instruct practice further.
Abstract: The effect of 11S/7S ratios on mechanical and barrier properties of soybean-protein-isolate films was evaluated. The tensile strength increased with an increase of 11S globulin ratio when it was higher than 50 % in soybean-protein-isolate films, and decreased with an increase of 11S globulin ratio when it was lower than 50%. Moreover, the total soluble matter of soybean-protein-isolate films decreased with an increase of 11S globulin ratio, while the elongation at break, moisture content, and optical transparency of soybean-protein-isolate films increased with an increase of 11S globulin ratio. Furthermore, 11S/7S ratios had no influence on the water vapor permeability of soybean-protein-isolate films. These phenomenon mainly resulted from that the matrix of soybean-protein-isolate films was mainly maintained by disulfide bonds when 11S globulin ratio was higher than 50%, while that was maintained by intermolecular hydrogen bonds when 11S globulin ratio was lower than 50%.
Abstract: A kind of SMS composite nonwovens with excellent antistatic property was developed by mixing the polypropylene resin and the antistatic agent. Mechanical property, air permeability, drapability and antistatic property of the products at different antistatic agent content were analysed. The results show that the antistatic property of SMS composite nonwovens was improved significantly by blending antistatic agent, Although the mechanical property, drapability and permeability is deceased slightly.
Abstract: The influence of ac driving current on the frequency dependence in the range from 0.1 to 20 MHz of the giant magnetoimpedance effect (GMI) of glass-covered amorphous microwires were investigated. The dependence of GMI for a range of values of ac current (from 0.5 mA to 20 mA) flowing along the microwire has been measured in as-prepared samples. The double-peak feature is changed to the single-peak festure and the magnetic field at which the value of GMI reaches a maximum should increase with the higher the amplitude of the ac at low frequency. It was found that the change of GMI related to circular coercivity.
Abstract: Elastic constants and some thermodynamic properties of Cu and copper oxides were studied by first-principles total energy calculations. The elastic constants of Cu and copper oxides were calculated on pressure. It was shown that the calculated elastic constants of Cu, Cu2O and CuO at zero pressure were well consistent with previous experimental data. The specific heat capacities and thermal expansion coefficient of Cu and copper oxides were successfully obtained. The calculated specific heat capacities of Cu were well consistent with the previous experimental data.
Abstract: It is of great importance to innocuity, minimization and reutilization of manganese slag generated in manganese product by electric furnace process. In the paper, ordinary Portland cement was replaced partly by manganese slag to then evaluate manganese slag’ effect on mechanical performances of them. The experimental results obtained show that ordinary Portland cement added less than 30% by manganese slag was improved in mechanical performances and the cement concrete added less than 30% by manganese slag was not changed significantly. To lower economic cost and achieve enhanced mechanical performances, manganese slag can be substituted partly to cement concrete.
Abstract: This paper describes an numerical method and simulation experiment investigation on the rail wear affected by the curve radius and axle load etc. the effects of curve radius and axle load on The effects of axle load and curve radius on total slippage of contact particles and friction work of wheel/rail are investigated with numerical methods are analyzed by kalker’s program CONTACT. The effect of curve radius and axle load on rolling wear behaviour of rail is investigated by simulation experiment. It is indicated that axle load and curve radius are important factors to effect rolling contact wear of wheel-rail, and there is a linear relationship between wear volume of rail and friction work of wheel/rail; The preliminary empirical formula between wear volume of rail sample and friction work is given by analysis the experimental and calculation results, the formula offers a certain reference value for researching wear of wheel-rail and predicting wear volume of rail.