Materials Science Forum Vols. 575-578

Abstract: On the basis of suitable arrangement for the special stress surrounding and parameters selection, Realistic Failure Process Analysis 2-D (RFPA2D) numerical simulation of extra-thick coal seams’ displacement and failure is carried out. It’s proved that the numerical simulation results are consistent with the in-sit measurement results of top coal’s advance supporting stress and deep-hole displacement. So application of RFPA2D in sub-level caving mining extra-thick coal seams is reliable. It’s also proved that application of RFPA2D in sub-level caving mining can do great help to study the nature of top coal’s displacement, fragmentation and failure process of extra-thick coal seams. As the top coal’s displacement and failure situation under certain circumstance can be forecasted by RFPA2D numerical simulation, the most suitable top coal thickness under certain circumstance can be predicted by RFPA2D numerical simulation test, which can do great benefit to extra-thick coal seams’ safe and high efficient mining.

Abstract: The spatial phase locked scanning electron beam lithography systems (SPLEBL) is a new lithography technique with a pattern placement precision of about 1 nm. The SPLEBL technique can solve the major problem of poor placement accuracy existed in the conventional scanning electron beam lithography for that it uses a Fourier technique to detect the beam position in real time during exposure. The fiducial grid plays a key role in SPLEBL. The two-dimensional global fiducial grid with a grid period of 250 nm placed on top of the e-beam resist used in SPLEBL with high contrast, high brightness, long-range spatial-phase coherence, large area and a pattern placement precision of about 1 nm is fabricated using optical interference lithography in this article. The detail fabrication process is described and the SEM images of the fabricated grid are also presented in this paper. Only one evaporation step and several spin-coating steps are required in the fabrication process, so it is simple and user friendly.

Abstract: On the basis of similarity principle a water-simulative study of the process of rotating impeller degassing (RID) was executed by means of self-made purifying system. The influencing factors on the RID process were studied and laid a theoretical basis for the further development of this kind of technique. The shape of vortex originated in rotating of impeller and its adverse effect on degassing effectiveness were discussed. Meanwhile the influences of shape as well as position of bluff body on degassing efficiency were investigated. The impacts of parameters such as gas feed rate and rotational speed of on degassing efficiency were discussed. The result revealed that the structure and design parameters of impeller are the decisive factors of effectiveness of RID facilities, and the design of the swivel head ought to aim for increasing the additional turbulent shear stress on air bubble and improving the degassing condition.

Abstract: In this paper, existing models of fabric’s optical behaviors are classified and estimated briefly. Then, basing on the optical theories, this paper abstracts the commonness of fabric’s optical behaviors and put forward an improved model of them, which includes a physical model and its corresponding mathematical model. The physical model describes the light falling on fabrics splits into six components, which compose another four components. The ten light components divided by the incident light yields ten light component parameters, which are functions of the wavelength. The mathematical model connects the ten light component parameters and gives formulas to calculate them. Thus, the light component parameters are connected with the basic optical parameters and structural parameters of fabric. This improved model provides a fundamental and theoretical guide for studying fabric’s optical properties systematically, which has been proved to be effective in solving some problems related fabric optical properties.

Abstract: The chemical components of red 1%NaOH extractives of Castanopsis fissa wood chips were separated and identified by GC/MS after enriching and dissolving in benzene-methanol. Relative content of each component was determined by area normalization. 24 compounds representing 71.87 % of the extractives were identified. The most abundant constituents were hexadecanoic acid,methyl ester(17.08%), 9-octadecenoic acid (z)-,methyl ester (cas) (15.08%), 2,3-diphenyl-5-(3-methoxyphenyl)pyrrole(7.05%), hexadecanoic acid,ethyl ester (cas) (7.02%), 9,12-octadecadienoic acid (z,z)-,methyl ester(4.82%), 9-octadecenoic acid (z)-,ethyl ester (cas) (4.70%), octadecanoic acid,methyl ester(2.66%), 10-methoxy-nb-à-methylcorynantheol(1.90%), di-(9-octadecenoyl)-glycerol(1.70%),ethyl linoleate(1.09%), 9-octadecenoic acid (z)-,methyl ester (cas) (1.03%), eicosanoic acid,methyl ester(1.01%), and so on.

Abstract: The preparation technologies of thermal barrier coating by the Electron Beam Physical Vapor Deposition (EBPVD) technique were briefly introduced in this paper. And design principal of thermal barrier coating is discussed, at the same time the selection of raw material was also taken into account. On the basis of several assumed perfect conditions, a reasonable Finite Element Analysis (FEA) physical model was built up in order to exactly describe the whole deposition process. Taking the advantage of the large-scale commercial software of FEA, the distribution of residual stress and the possible displacement tendency were obtained. The analysis results show that: with the increasing substrate preheating temperature, the inter-laminar shear stress increases but the axial residual stress decreases. And the probability of cracking after de-bonding tends to enhance as the thickness of deposition coating is increased. Also it is verified that the FE model has produced little numerical error.

Abstract: This paper deals with the temperature measuring of the glow discharge zone in double glow plasma surface alloying process. CCD technique was employed to get the temperature distribution profile. The results show that CCD method is a simple and effective non-contact temperature measuring technique, applicable in fields of low temperature and high temperature plasma processes.

Abstract: Surrounding rock mass stability is one of the key technical problems in the design of the diversion tunnels in Jinping II Hydropower Plant Project. The major difficulties lie in three facts: (1) high stress induced by the great depth; (2) the brittle failure characters of marble; (3) the interaction of these four tunnels. A systemic procedure is introduced in this paper. Firstly, the integration of the code FLAC3D and the multivariate linear regression method is adopted to back analyze the in situ stress field. Then the mechanical parameters of the surrounding rock mass are back analyzed based on the PSO (Particle Swarm Optimization) algorithm and the code FLAC3D. The stress release method is adopted in the numerical analysis of the excavating and supporting process of tunnels by the code FLAC3D. Finally, the multi indexes integration method is presented to analyze and evaluate the stability of the tunnels and to validate the rationality of the design scheme.

Abstract: In this paper, the functions and tasks’ distribution of control system in thermo-mechanical simulator are described.The characters and methods to solve multi-closed loop tasks and contradiction among synchronous collection are explained. This work combines technical processes. and introduces design feature and principle of operation of control system that is made up by different controllers.

Abstract: This paper discusses the magnetic drag force resulting from the relative motion of a permanent magnet moving along a finite dimensional conducting plate. The image method with imaginary eddy currents is investigated. Boundary conditions are established to ensure that the eddy currents vanished at the boundaries of the conducting plate. Magnetic drag force is computed based on the eddy current distributions using Lorentz force law. A test system is built to demonstrate the magnetic brakes arose from the electromagnetic interactions.