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Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl₂F₂) in the presence of water vapor and oxygen was studied over solid acid MoO₃/ZrO₂ using a fixed-bed reactor. The adsorption velocity equation was calculated by Bangham Equation. Reaction energy was determined by Arrhenius Equation and it was 123.12 KJ.mol^-1.

The Φ730 / Φ340 mm hollow ingots of 2A14 aluminium alloy were produced by conventional and electromagnetic stirring (EMS) DC casting with extremely fine grain morphology. The results indicate that the metallographic microstructure of the alloy was more uniform and homogeneous in the EMS hollow ingot and the finer grain size was obtained. The average grain size dramatically decreased from 115 μm to 70 μm with applying EMS. The macrosegregation patterns of Cu element in EMS and conventional hollow ingots along the radial direction were both following the similar trend that positive segregation occurred in inner subsurface and middle section. Meanwhile negative segregation occurred in section offset to inside of centerline and outer surface. The extent of macrosegregation in EMS hollow ingot was severer than that in the conventional one. The mechanism of EMS was discussed to reveal its effect on the microstructure and macrosegregation.

The welding temperature field of twin-wire submerged arc welding (SAW) in an X80 pipeline steel welded joint was analyzed using a three-dimensional (3D) finite element (FE) model. Taking into account nonlinear relationships between temperature and mechanical properties, a coupled thermo-mechanical FE solution was used to obtain the temperature distribution for varying set of welding conditions. Effect of welding speed, inter wire spacing on welding temperature field were studied and presented. It is found that welding speed and inter wire spacing play a significant role in deciding the temperature distribution of twin-wire submerged arc welding. Simulation results were well consistent with theoretical analysis.

The author firstly summarized the principles, performance and theoretical resilience model of the new type electromagnetic damper. The theoretical resilience model is further improved on this basis—normalizing the impact of vibrant frequency and vibrant amplitude on resilience as the impact of single parameter velocity amplitude. The results show that improved model can give a better effect as shown in experiment. This lays a sound foundation for simulation calculation in developing products using for practical engineering and installing the structural vibration reduction system of electromagnetic damper.

Traditional medical image enhancement method has some disadvantages. They can not significantly improve the medical image edge, texture and detailed information. Besides the enhancement effect is susceptible to interference noise information. This paper proposed enhancement algorithms combining bidimensional empirical mode decomposition and the wavelet edge enhancement method. The first step is using the method of bidimensional empirical mode decomposition to process medical image, achieve image information with different frequency. And then our method using wavelet transform to enhance different frequency image edge, texture information. Through the comparison of proposed method with the existing method, it has been verified the proposed method has a better effect in the detail enhancement of medical images.

A series of the experiments were carried out on the Nandan lead-zinc tailings management and one bioleaching method was proposed with the purpose of recovering the valuable metal such as Zn. Firstly, multi-elements analysis was performed to provide theoretical data. Secondly, the effect of the pH on the bacterial growth and Fe²⁺ oxidation was investigated. The results showed that pH at 2.5 was the optimum for the bacteria. The concentration of the bacteria at pH 2.5 can be up to 9.3×10⁷ cells/mL. Finally, the bioleaching treatment was performed to study the potential of bioleaching the tailings. The data illustrated that the method of bioleaching can extremely recover metals such as zinc from the tailings, which provided novel insights into metal recycling.

A novel robust control scheme for decentralized generator excitation and valve coordinated control systems to improve power system stability is proposed. By utilizing generator terminal voltage magnitude and phase angle to represent the interactions among generators, decentralized generator excitation and valve coordinated control in multi-machine power systems is achieved. The control is realized by robust parametric approach. Simulation results show that the proposed robust parametric coordinated control can improve power system stability.

This study was a continuation of previous work designed to further explore the effect of different culture condition on the recovery of the valuable metals by bacteria. The experiment focused on the Nandan lead-zinc tailings from different depths. First of all, the study systematically performed multi-elements analysis. Subsequently, the effect of the temperature and agitation speed on the bacterial growth was investigated. The data revealed that the temperature of 35°C and the agitation of 160 rpm were the optimum culture conditions for the bacteria. Finally, the bioleaching experiments were performed to explore the ability of bioleaching the tailings. The study illustrated that the microorganism was able to effectively extract valuable metals from different depths samples.

Power flow shift being one of the main reasons that cause a large-scale blackout of power system, it is important to get the power flow shift under control at the beginning of the failure. In view of multidrop overload which frequently occurs in power outage, a comprehensive evaluation method is proposed to control the power flow shift. This method synthetically considers the control nodes' ability to eliminate the overload of the transmission in combination with PCA in which nodes' sensitivity of branch is selected as the evaluation index, divides them into two types (nodes that increase the power output to branch and others that decrease the power output to branch) and then obtains the control nodes' operation sequence. Additionally, a reverse equal matching adjustment is used to realize the control over multidrop overload. Typical numerical example is used to verify the effectiveness of the comprehensive evaluation method.

A series of porphyrin sensitizers with different central metal ions (PMn, PFe, PCo, PNi, PCu, and PZn) have been studied based on density functional theory (DFT). The geometric structure of the dyes was optimized and the frontier molecular orbital were calculated. The result shows that the LUMO levels of PFe, PNi and PZn were much lower than that of PMn, PCo and PCu, which suggest a lower energy barrier for electron transfer from the donor to the acceptor tunneling. Furthermore, the energy gap of HOMO and LUMO for PFe was only 0.81 eV, it indicates a significant red shift of the absorption spectrum. The LUMO of PMn, PNi, PCu and PZn were mainly decocalized on the porphyrin core and the bridge moiety, which was beneficial to electronic transport.