Applied Mechanics and Materials Vols. 155-156

Abstract: An indoor simulation experiment has been carried out to study the effects of Roxarsone on the soil neutral phosphatase, catalase and urease activity. The result showed that the enzyme activities were reduced by the Roxarsone, and the effect degree was aggravated with the increasing consistency. It also showed that inhibition of various enzymes on the rise - decrease trend during the whole incubation period reached its peak on the tenth day as 54.71%,33.92% and 13.81% sorting the phosphatase, the catalase and the urease in a descending order consulting the enzyme sensitivity to Roxarsone. Taking the ED10 as an example, which is 18.83, 48.31 and 185.2 mg.kg-1 on the tenth day: Negative exponential growth model were used to fit the regression rate of enzyme activities with time indicating that the time of Roxarsone toxic effects on soil enzyme extended with the consistency being increased.

Abstract: 45 steel was selected as the testing material, QPQ salt bath treatment was conducted by nitriding at the same teperature of 565°C for various time, followed by the same post-oxidation process. Characterization of modified surface layers was made by optical microscopy, X-ray diffraction and corrosion test. The results showed that the cross sectional microstructure was consisted of a thin oxide layer of Fe3O4 at the external surface formed during post-oxidation, a bright zone of εnitrides at the subsurface formed during nitriding and a diffusion zone related to the core. The corrosion resistance of 45 steel in hot water can be significantly improved by QPQ complex salt bath treatment, and the suitable duration of nitriding and post-oxidation to improve the corrosion resistance was 90min and 100min, respectively.

Abstract: Using first principles calculations based on the density functional theory, we have studied the structural and mechanical properties of Ti1-xAlxN and Ti1-x-yAlxSiyN metastable phase. Focus on the calculation of the Ti1-x-yAlxSiyN the cohesive energy, mechanical constants, elastic modulus and shear modulus. These calculated values were analyzed, then we obtained that Ti1-xAlxN lattice parameter decreased after adding Si, while the cohesive energy was rising, the mechanical properties decreased, indicating that in the case of the Al content determined, the structure of Ti1-x-yAlxSiyN is more stable than Ti1-xAlxN, but the mechanical performance ,stiffness and brittleness are reduced.

Abstract: The fracturing fluid with solid particles in the process of high-speed injects to high pressure pipe manifolds will cause serious erosion damage, lead to serious material loss and equipment failure. Thus the prevention of erosive wear on high pressure pipe manifolds is regarded as one of the most important problems in practical engineering. In this paper, a new type of test machine was developed to simulate the erosive wear behavior of metal materials caused by the multiphase fluid such as fracturing fluid, and study the erosion failure mechanism by various metal erosion influencing factors including the velocity of multiphase flow, solid particles of fracturing proppant and impact angles, etc. The erosion-wear experiments on 30CrMo steels used in high-pressure pipe manifolds is described in detail. Finally, the microcosmic surface testing was also used to analyze the erosion failure mechanism of metal materials for high pressure pipe manifolds.

Abstract: The influence of low temperature plasma treatment on the interfacial performance of aramid fiber was studied. SEM and XPS were used to investigate the surface morphology and the chemical elements of the fiber before and after plasma treatment. The etching degree of the surface of aramid fiber was determined by wettability experiments and tensile/bending measurements before and after low temperature plasma treatment. The result showed that under the condition of 200W/10min/10Pa, the etching effect of the surface of aramid fiber was optimal.The wettability of fiber obviously improved and the bending intensity increased by about 30%.but the tensile performance of aramid fiber did not change much.

Abstract: Load-Unload Response Ratio (LURR) is one of the parallel applications for seismological analysis and requires large amount of computation resources for simulation. In order to accelerate the LURR calculation and optimize the resource allocation, this paper presents a REST style Web Service LURR-Grid. Based on Globus Toolkit, AIS and MyProxy, LURR-Grid is able to accept LURR job request and conduct LURR calculation tasks on Grid Resources. Using MDS in Globus for resources and GRAM5 for job execution engine, LURR-Grid schedule the task using the SED algorithm. The Experiments proves the LURR-Grid is scalable and efficient in resource allocation.

Abstract: Energy consumption and economic growth are inseparable, along with the constant expansion of the economy, increasing energy consumption in China, a huge energy consumption is greatly beyond the capacity of China's energy supply, while causing serious environmental pollution, the threat of China sustainable economic development. In this paper, China's energy consumption and economic growth analysis of the relationship between research, through error correction model to arrive at energy consumption and economic growth of the long-term equilibrium relationship, and accordingly put forward a sound proposal related to this relationship, for the government to take certain economic reforms was provided.

Abstract: Objective: probe into the influence of comprehensive materials multimedia on the students' sports motivation. Methods: the present study proceeds from the mode of teaching in the traditional physical education by the literature method, experimental method, Delphi method and the mathematical statistical analysis method to the comparison of the means of comprehensive materials multimedia in the physical education classes with the traditional education and study by the tool of the Sport Motivation Scale. Results: Practice of comprehensive materials multimedia in physical education can improve the students' sports motivation, activate their intrinsic motivation and guide it into a more active tendency.

Abstract: In order to improve the performance of gypsum mould, dry grinding process was applied to the pretreatment of gypsum powder and the effect of the ball-milling time on the performance of gypsum powders was mainly studied in our work. X-Ray powder diffraction (XRD) and scanning electron microscope (SEM) were employed to characterize the phase compositions and microstructures of gypsum mould. The results show that the initial and final setting time of gypsum slurry reduces with the increasing of ball-milling time. But the initial and final setting time changed slightly when the ball-milling time was extended to 1 hour or more. Furthermore, the water absorption of gypsum moulds made by the pre-grinded gypsum powders was increased by 42.0 percent in the case of 2 hours’ grinding time, yet the flexual strength of the mould was slightly decreased by 12.5 percent. The main phase of gypsum powder was unchanged, but decrystallization degree increased after dry grinding process. Meanwhile, the crystal orientation and particle aggregation of the gypsum powders were destroyed, and the particle length of that was shortened. As a result, the gypsum moulds obtained by the as-treated gypsum powders have high porosity and water absorption.

Abstract: As ELID grinding technology is characterized by simpleness, practicality, low cost and so on, it is wildly used in ultra-precision sharpening, ultra-precision grinding, ultra-precision polishing and some other fields of difficult-to-cut material. ELID grinding technology was applied in the grinding of cutting tool in this paper, and the cutting tools with nano-grained cemented carbide, common cemented carbide, nanoY-TZP ceramics and some other materials were respectively grinded. Then, the surface quality of their anterior and posterior grinding horns and their edge radius were studied and compared with traditional grinding technology of cutting tool. The results show that the surface roughness and edge radius of nano-grained cemented carbide cutting tool are respectively Ra2nm and 0.3μm, the surface roughness and edge radius of common cemented carbide cutting tool are respectively Ra20nm and 1μm and the surface roughness and edge radius of nanoY-TZP ceramic cutting tool are respectively Ra60nm and 0.2μm after grinding by applying ELID grinding technology, which are far better than that from traditional grinding technology; this further proves that the adoption of ELID grinding technology in the grinding of cutting tool is feasible.