Advanced Materials Research Vols. 291-294

Abstract: Red mud has been used to develop effective adsorbents to remove phosphate from aqueous solution. The effects of different dosage, pH of solution and reaction time on adsorption have been examined in batch experiments. It was found that red mud samples show higher removal efficiency for phosphate. The results showed that phosphate removal efficiency was found to be 97 % with optimal reaction conditions initial phosphate concentration 100mg L−1, red mud dosage 10g L−1, pH 2.0, respectively. The phosphate removal efficiency of the red mud adsorbents decreases with increase of pH.

Abstract: In this study, production of Si-Al-Fe alloy with coal fly ash and bauxite as the major raw materials in the induction furnace at high temperatures were studied. The results show that carbothermal reduction of mixture of coal fly ash, bauxite, hematite, silica and CaF₂ in the induction furnace can produce Si-Al-Fe alloy, and it can therefore improve the utilization value of fly ash and reduce its pollution to the environment. The reduced alloy phase mainly contains ~23% Si, ~19% Al and ~52% Fe, and small amounts of P and S. The main phases of alloy are Al_0.5Fe₃Si_0.5, FeSi, SiC, Si₅C₃, FeC, and TiC.

Abstract: This article utilizes the synthetic analysis method to propose the proposition of excellent engineers’ quality training. Excellent engineers are those who are outstanding and better than general engineers. The paper discusses the background and the practical demand of excellent engineers’ developing, it also expounds the basic qualities that excellent engineers should possess and clarifies the trainning of excellent engineers is the higher project education’s sacred mission. The conclusion is: it should take the way of co-production and learning, and the government departments should provide support in politics, economy, law and so on, then it will help to improve the enterprises’ initiative to participate in engineering talents’s training.

Abstract: Uncertainties for thermal protection efficacy caused by deviations of the values of phase change materials (PCMs) properties (including conductivity, heat capacity, thermal conductivity, latent heat and phase transition temperature) were studied based on our previous study. Our results suggested that the radius of the micro/nano PCM particle, and the upper and lower phase transition temperatures of the PCM should be carefully measured before performing thermal protection by PCMs during hyperthermia. The results will further help us to enlarge the application of clinical hyperthermia in cancer treatment and optimize the treatment protocol of thermal protection by PCMs.

Abstract: Vicat softening temperature (VST) is one of the most important parameters to evaluate heat resistance of thermoplastic materials. However, the initial test temperature is difficult to control, which may reduce the testing efficiency and the precision of VST. Moreover, according to the procedure of GB/T 1633-2000, the specimen should be placed horizontally under the indenting tip of unloaded rod for 5min. After that, add a sufficient weight to the weight-carrying plate, and then set the penetration indicator to zero to start the experiment. However, the waiting period between adding the extra mass and starting the test may be different during the real operation. Such longer or shorter waiting periods can also influence the tested VST. In this paper, ultra-high molecular weight polyethylene (UHMWPE) was used to discuss the influence of initial temperature and waiting period on its final VST. The results show that, in order to satisfy the practices of standard GB/T 1633-2000, the initial temperature and the waiting period should not exceed 40°C and 25min, respectively.

Abstract: In the paper, we selected high manganese steel as the binder and titanium carbide as the hard phase, which could attain single austenite bonded titanium carbide after water toughening in order to combine excellent toughness of matrix with good wear resistance of TiC organically for some components that required excellent toughness and wearability. By dint of SEM, XRD etc. detection means, effects of ingredient proportion, preparation technics and heat treatment parameters on hardness, microstructure, and mechanical property were investigated; so the composition and preparation process of TiC cemented were confirmed, which was applied to grinding with large impact force.

Abstract: In order to study the inherent characteristics and aseismic characteristics of ancient Chinese structure, according to the reconstruction engineering data of the embrasured watchtower on Yong-Ning Gateway of Xi'an City Wall, two finite element models (local and whole models of large timber frame of the embrasured watchtower are built by applying semi-rigid spring element to simulate the mortise-tenon joint, the bracket set and the plinth (that is column base) joint in the real timber structure. The first 10 natural frequencies as well as corresponding vibration modes of the structure are obtained using the method of Block-Lanczos. With full transient analysis, considering time history analysis of two models under the three earthquake excitations of the El-Centro wave, Taft wave and the Lan-Zhou artificial wave, the model displacement and acceleration time history curves were got. By comparing the two model’s basic modeling parameters as well as, the relative errors of the frequencies, the vibration modes, the excitation effects and, the feasibility of using the local model instead of the whole model in the structural analysis were to be discussed one by one. the results show that the local model can stand for the whole model for structural analyzing. Based on the results, the analysis methods and the relevant conclusions could be referenced to study the preservation and the rehabilitation of the ancient Chinese timber structures.

Abstract: Single polytetrafluoroethylene composites were prepared of cold compression molding and free sintering with various cooling conditions. The microstructure and properties of single polytetrafluoroethylene composites were investigated. The tensile and flexural properties of PTFE SPCs were investigated with various cooling conditions. The results show that The tensile strength and the tensile modulus of the samples cooling with the furnace are higher than these of the samples cooling by air, and cooling by water. The effect on flexural properties is the same to that on tensile strength. The structure of single polytetrafluoroethylene composites were analyzed by IR and SEM. It shows that cooling with the furnace is the better way for preparing of single polytetrafluoroethylene composites.

Abstract: The author analyzes the problems existing in the traditional assembly system and puts forward a new method based on the motor control. This paper introduces the design and development of the automatic assembly system of ultrasonic cleaning transducer. In the system we use photoelectric isolation technology to solve the problems that driving circuit interference control chip while using a chip control many motors and this simplify the assembly system structure, reduce the cost of the assembly system and improve the assembly system automation and precision.

Abstract: The paper expounded the impact of coal gangues on environment. Also it deals with the feasibility of making polymeric aluminum and ferric chloride (PAFC) using coal gangue. Through orthogonal test, the paper explores such factors as roasting temperature, roasting time, hydrochloric acid concentration, reaction temperature and grain size influence on the making process, and give the best operation conditions: roasting temperature is 700°C, roasting time is 1.5～3.5h, hydrochloric acid concentration is 25%～30%, reaction temperature is 120°C and grain size is 60 mesh. At last, the qualities of products are analyzed and the conclusion is given: it is feasible to make PAFC from coal gangue and it should be popularized.