Advanced Materials Research Vols. 383-390

Abstract: The designs to improve the problem such as large temperature fluctuations in polymerization reactor affect the quality of CH₄. The slave computer MCU controls temperature sensor to detect temperature; the host computer PC monitors temperature of polymerization reactor, and draws a monitoring interface by Kingview. In order to control the temperature of polymerization reactor, the MCU uses Dahlin algorithm. Meanwhile, the system has real-time temperature displaying, recording, storing, alarming, serial communication and so on functions. Establishing the control system based on the PROTEUS simulation. Experiment shows that temperature is controlled at 200±3°C in the constant temperature phase, and it is superior to polymerization reactor required at 200±5°C.System Experiment Completely Meet the Requirement.

Abstract: After FBG was nickel electroless plated, the stresses and strains on the FBG and nickel eclectroless plated layer under varied temperature were analyzed in theory. In order to verify the theoretical analysis of stress and strain,a finite element analysis software(ANSYS) was used to simulate the stresses and strains on the FBG and nickel ececltroless plated layer. The results of theoretical analysis matches the ones form simulations well.

Abstract: This work deals with the welding simulation by the Finite Element Method (FEM). For the tube plate welding structure features of Membrane water-wall, the numerical computation method is applied to do the real-time simulation research on the temperature field and stress field during the welding process. The implemented models include a moving heat source, temperature dependence of thermo-physical properties, elasto-plasticity, non-steady state heat transfer, and mechanical analysis. The thermal problem is assumed to be uncoupled from the mechanical one, so the thermal analysis is performed separately and previously to the mechanical analysis at each time step. The mechanical problem is based on the thermal history. A special treatment is performed on mechanical elements during the liquid/solid and solid/liquid phase changes to account for stress states. The established simulation analysis method of welding temperature and stress field can provide theory foundation and direction for optimizing the welding structure design and standardizing the welding parameter.

Abstract: In view of the serious misalignment, the mathematical model's uncertainty, the characteristic of the system operating point changing fiercely of the heating furnace temperature control system, this paper designed a new type of intelligent control system - PID neural network system (PIDNN) which melt the PID control rule in the neural network. This system has the quick reasoning speed and the strong anti-interference ability.

Abstract: Combined with the flume experiments and 1D unsteady flow numerical model, the paper has investigated the overtopping breach process of the non-viscous embankment. The breach expansion and the variation process of water level above the breach gate have been studied by series of experiments. Considering the difficulty to monitor the discharge through the breach, 1D unsteady flow numerical model has been applied to simulate discharge variation process. It is found that the width of breach gate and water level above the breach gate are the two key factors which influence the discharge through the breach significantly. Discharge variation process through the breach gate is consistent with the flow rule of side weir. The calibrated flow coefficient is from 0.389 to 0.696. The investigation results can provide scientific basis for disaster prevention and evaluation of embankment burst.

Abstract: The formation process of Galfan alloy transition layer in Sendzimir process was studied by SEM and EDS method. The results showed that the thickness and aluminum content of transition layer increased with the increase of dipping time. Hypoeutectic structure of zinc appeared as the decrease of Al in Galfan coating. The Fe content decreased from the steel matrix to alloy layer.

Abstract: Both of noise and building energy efficiency are attached importance to in the world. A novel material is developed to control noise, save building energy and decorate for buildings. Porous absorber, cavity resonator resonance sound absorber, film resonance sound absorber, functional absorber and high sound absorber are utilized to improve the sound absorbability. Perlite, Ordinary Portland cement, silicon fume, re-dispersible emulsion powder or emulsion, air-entraining agent, superplasticizer, short fiber and mesh fabrics are used to prepare novel material. Organic silicone waterproof material is used to prevent it from destroying, assist for sound absorbability and decorate for surface. After designing wedge sound absorber by mould, forming cavity resonator resonance sound absorber by air-entraining agent, and controlling compression ratio, diameter of perlite grain and cement dosage, final performances of sound absorbability and heat preservation can meet requirements of ASTM C423-84A and GB/T 20473-2006 respectively.

Abstract: Flame sprayed iron tailings coatings on the boiler steels are characterized before and after melting. The attempt has been made to investigate the microstructure, erosion resistant, wear resistant of the coated and melted samples. The techniques used are SEM and XRD. The results show that: Good adhesion between the coating and the substrate is caused by the formation of Al₂SiO3 and (Cr, Fe)₂O₃ at the interface of the coated specimen. The stainless steel substrate with ceramic coating has a higher erosi_{Subscript text}on resistance than the uncoated specimen because the mixed powder changes to a glass-coating in the high temperature heat treatment, and a few mullite are formed. Mullite has the high hardness value that makes the hardness of the coating increased. The wear resistance of the coated samples is better than that of the uncoated samples because glass-coating is more smooth than the uncoated specimen and the mullite in the coating has the high hardness value that makes the hardness of the coating increased.

Abstract: Aiming at the durability deterioration of the coating of steel structure because of being eroded in sandstorm. through the erosion test to the coating of steel structure by airflow jet with sand at low erosion-angle, the mass-loss measurement method is used to assess erosion-wear degree of the coating, Observation of microstructure of the erosion zone using SEM to analyze the erosion-wear mechanism of the coating, and proposes a assessment formula for assessing the erosion-wear degree of the coating. Results show that the erosion-wear mechanism is that erosion is mainly micro-cutting role at low erosion-angle, materials hardness is decisive factor, and erosion is mainly compression deformation at high erosion-angle, materials toughness plays decisive role, as the coating is low hardness and high toughness materials, which is eroded more seriously at low erosion-angle. The reliability of the assessment formula is verified to assess the erosion-wear degree of the coating. The study will provide basis for exactly assessing the durability of steel structure.

Abstract: This paper researched on the adsorption kinetics and thermodynamics of the typical components of petroleum hydrocarbon-benzene, naphthalene, phenanthrene and their mixed solution on the typical media-the medium sand from the aquifer in an oil contaminated field, with a self-made rotary adsorption device. The result showed that the adsorption of the three adsorbates on the media follows the Henry adsorption model, no matter when they are separated or mixed. The adsorption capacity order of benzene, naphthalene and phenanthrene on the medium sand is phenanthrene> naphthalene>benzene, when they are separated or mixed. Comparing with the adsorption capacity when the adsorbates are single, benzene and naphthalene in the mixed solution shows stronger adsorption capacity, while phenanthrene carries on less adsorption capacity.