Applied Mechanics and Materials Vols. 198-199

Abstract: Shape memory alloy (SMA) has a good application prospect in structural vibration control due to its unique shape memory effect and superelasticity. First, the characteristics of SMA is briefly introduced. This paper then reviews research results on SMA for passive energy dissipation in the past decades, including development of different mechanisms of SMA-based passive devices and their performance tests and application research. Finally, application of SMA for passive energy dissipation is prospected.

Abstract: In this paper, the Neimenggu high alumina coal gangue was calcined at 400°C~1000°C, its micro-structure in different calcining temperature was studied using XRD and IR, and then the preferred activated condition and the PAI were investigated by testing the strength of cement mortars with activated coal gangue. The result shows that: the optimal calcining temperature of the gangue is 800°C, at this temperature the high activated SiO₂ and AI₂O₃ can be decomposed from the gangue. The activity of the original gangue is very high, the PAI of the cement mortars with 800°C activated coal gangue can achieve to 126%, and thus can be used as high activity cement admixture. The PAI of the high alumina gangue is higher than that of coal gangue from other parts of China.

Abstract: Bulk metallic glass (BMG) formers are multicomponent alloys that vitrify with remarkable ease during solidification. Technological interest in these materials has been generated by their unique properties, which often surpass those of conventional structural materials. The metastable nature of BMGs, however, has imposed a barrier to broad commercial adoption, particularly where the processing requirements of these alloys conflict with conventional metal processing methods. Research on the crystallization of BMG formers. In this paper, we fabricated metallic glass of Nd-based and carried out experimental research. This kind of metallic glass has shown a distinct glass transition and stable super-cooled liquid region. At the same time, we find the paramagnetic performance of Nd-based metallic glass is different from other hard magnetic alloys at ordinary temperature. The DSC experiment indicate that the glass transition temperature increase with the heating temperature.

Abstract: The aqueous solution polymerization of acrylic acid, acrylamide and oxidized starch under single mode microwave irradiation was studied, and a polymer suppressant was synthesized. The factors that influence on performance of the polymer suppressant were discussed, including microwave irradiation time, neutralization degree of acrylic acid (AA), the dosage of oxidized starch. The polymer suppressant was characterized by IR and scanning electron microscopy (SEM). Results indicated that the optimal synthetic conditions are as follows: microwave irradiation power, 300 W; radiation time, 2 mins; 50% neutralization degree of the AA; m(AA) : m(AM) : m(oxidized starch)= 5.0 : 3.3 : 3.4, weight ratio initiator in the feed is 0.4%, respectively.

Abstract: Based upon the density functional theory (DFT) in this paper, the first-principles approach is used to study the electronic structure of different cross-sectional diameters of ZnO [0001] nanowires of wurtzite structure. The results show that ZnO [0001] nanowires have a wide direct band gap. Located in the G-point of the Brillouin zone the conduction band minimum and valence band maximum are relatively smooth. The conduction band is mainly composed of Zn 4s and Zn 4p states, and the valence band is composed of Zn 3d and O 2p states. The effective mass of conduction band electrons and valence band holes are large while their mobility is very low which show that conductive ability of pure defect-free [0001] ZnO nanowires is weak. Along with the increase of the cross-sectional diameters, the band gap gradually decreases that indicates quantum size effects are obvious in the nano size range.

Abstract: Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.

Abstract: The effects of different pure Al compositon in the pack powder on aluminide coating formation of a new kind of Ni-Cr-W-Al nickel-base superalloy by pack cementation aluminizing was investigated. The content of pure Al powder is 15% and 30% in the aluminizing agent. The microstructure and phase composition of diffusion coating was studied.

Abstract: with DLC coating spinning rings as the subject, focuses on the mechanism of damage on spinning ring track caused by textile fiber fabrics adhering to spinning ring surface and relevant adhesive wear and fatigue wear. Aiming at its failure, single DLC coating is substituted by Ti-DLC coating spinning rings. The process after improvement adopts unbalanced closed magnetron sputtering ion plating and Ti-doping multi-layer composite coating technology to prepare Ti-DLC composite film on the surface of spinning rings under the condition of basic temperature below 100°C. As indicated by the study on the impact of different Ti contents on friction and were performance of the film, improved Ti-DLC coating spinning rings are superior to DLC coating spinning rings in terms of deposition rate, adhesion, hardness, wear resistance, friction coefficient and wear rate, ensuring better adhesion resistance and fatigue resistance.

Abstract: Due to the critical positions of the studies of protein folding in medical and biological systems, the intelligent computation has been playing more and more important role in modeling and optimization for protein folding systems. This paper presents the applications of hysteretic optimization (HO) being a recent proposed physical principle inspired intelligent optimization solution for a 3D protein folding problem with lattice model. According to the characteristics of 3D protein folding model, the four key ingredients of HO approach, namely dynamics, distance, reference states and point of avalanche, are well defined. A proposed modified HO algorithm is successfully implemented for studies on 3D protein folding problems. Furthermore, the benchmark based numerous simulation results show the efficiency of the proposed HO method, and the relationship between the HO parameter setting and the resulting performance.