Materials Science Forum Vols. 575-578

Abstract: Flashover in compartment fire itself is a catastrophe process. Its catastrophe behavior can be analyzed, and its topological function equation can also be set up by catastrophe theory. On the basis of analyzing swallowtail catastrophe characteristic, a flashover model of hot smoke layer, which is established based on energy conservation, is transformed in the dimensionless form firstly, and then diffeomorphism is applied to simplify it. By these transform, a catastrophe potential function is gained. The format of the catastrophe potential function makes it clear that this type of flashover belongs to swallowtail catastrophe. Subsequently, taking passenger carriage fire as an idiographic object, the connection between system control variable and burning condition is discussed. The results show that the space of catastrophe bifurcation in muster divide the fire into two section, namely flashover section and non-flashover section. If in flashover section, an unstable point can be obtained by using qualitative curve or differential coefficient curve of potential function. Furthermore, the temperature of hot smoke layer is calculated by the value of the critical point when flashover occurs. The calculation case of passenger carriage fire shows that the temperature of hot smoke layer is 625.3°C when flashover occurs in the carriage, which is agreement with real instance.

Abstract: Asphalt pavement serving as solar collector has been developed for the heating and cooling of adjacent buildings as well as to keep the pavement ice-free directly. Material parameters such as thermal conductivity and heat capacity are some of the critical parameters related to the efficiency of the asphalt collector. Graphite powders were utilized as thermal conductive fillers to make asphalt collector conductive so as to improve the efficiency of the asphalt collector. The material parameters change with the addition of graphite consequently. In order to access the solar energy absorbability of conductive asphalt collector, it is necessary to predict the temperature distribution within the asphalt layers. A transient, two-dimensional finite element model is developed to predict temperature distributions in conductive asphalt solar collector due to material parameters. The ability of accurately predict asphalt pavement temperature at different depths will greatly help pavement engineers in determining the solar energy potential of conductive asphalt collector. The results from the prediction model show that the surface temperature of pavement decreases slightly with addition of graphite. The differential maximum asphalt temperature variation at a depth of 10cm is significantly more than that at the surface. Higher temperature and lower temperature gradient can also be observed at the depth of 10cm because the heat conduction is accelerated by the addition of graphite.

Abstract: The chemical components from superheated water extractive of fresh Phyllostachys heterocycla shavings were separated and identified by GC/MS after enriched. Relative content of each component was determined by area normalization. 31 compounds representing 99.99% of the extractives were identified. The main and abundant constituents were as: heptacosane (35.37%), 2,2,4-trimethyl-3- (3,8,12,16-tetramethyl-heptadeca-3,7,11,15-tetraenyl)-cyclohexanol (16.25%), isochiapin B (12.24%), tetradecane, 2,6,10-trimethyl- (cas) (7.59%), dibutyl phthalate (5.66%), etratriacontane (cas) (4.89%), 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester (cas) (3.74%), phosphoric acid, tributyl ester (cas) (2.92%), silicone polymer (2.47%), silicate anion tetramer (2.43%), 2,3-dihydro-benzofuran (2.01%), quercetin 7,3',4'-trimethoxy (1.04%), 1-heptatriacotanol (0.98%) and so on. Most components of superheated water extractives of fresh Phyllostachys heterocycla are abundant and healthy to human, indicating that there are natural health elements in Phyllostachys heterocycla.

Abstract: The extractives from the fresh E. urograndis wood were obtained through red 1%NaOH solution. The chemical components for the extractives were identified by GC-MS. Relative content of each chemical component was determined by area normalization. Ninteen kinds of compounds representing 52.99% of the extractives which take on 36 peaks were identified. The result showed that the principal constituents were 9-octadecenoic acid (z)-, methyl ester (cas) (11.34%), 3-diphenyl-5-(3-methoxyphenyl)pyrrole(10.77%), hexadecanoic acid, methyl ester (cas) (6.23%), 9,12-octadecadienoic acid (z,z)-, methyl ester(6.16%), 9-octadecenoic acid (z)-, ethyl ester (cas) (3.17%), di-(9-octadecenoyl)-glycerol(3.14%), hexadecanoic acid, ethyl ester (cas) (1.93%), ethyl linoleate(1.81%), 3-acetoxychol-5-ene(1.62%), ethyl linoleate(1.60%), octadecanoic acid, methyl ester(1.05%)and so on. Therefore, this result reported in the present study for the first time provides the scientific basis for the further exploitation and development of E. urograndis wood. At the same time, the pollution prevention of the waste water of paper mill, wood industry would being realized from the results.

Abstract: Owing to two phases are continuous and penetrated each other, Interpenetrating composites exhibit good abrasive wear properties, can be an attractive candidate for structural and functional materials. Specifically, the abrasive wear model of IPCs is an important topic in the field of tribology. In present work, the model has been proposed according to the mixing rule. Many factors such as special topology structure characteristic of reinforcement, hardness and elastic module are discussed in this model. One kind of Al2O3/Mg composite with different volume content was fabricated and many test data of friction wear were obtained. These data validate the correctness and universality of model.

Abstract: How the volume resistance rate of the conductive polymer composite material such as nitrile rubber (NBR) filled with ACET changes with temperature is studied. How the volume resistance rate of different conductive polymer composite material is affected by the content of ACET is studied. Such cases are then explained theoretically.

Abstract: When Zn-Sn-Ni ternary alloy is electroplated on electrolyte copper foil, the surface properties can be comprehensively improved by using alkaline salt pyrophosphate solution. After the bath composition and processing conditions are optimized, and an appropriate additive is chosen, the SEM images shows the electrocrystalized substance obtained is composed of nano-crystals. Besides, XRD analysis on the deposits of electroplated Zn-Sn-Ni alloy shows Zn in the deposits exist in the form of metal compound, including δ phase Ni3Zn22 as well as γ Ni5Zn21. This indicates under the pyrophosphate salt the process of nucleation of Zn-Sn-Ni ternary alloy is similar to the process of three-dimensional successive nucleation controlled by diffuseness. All these demonstrate that after the disposal of this study, the corrosion resistance, the heat resistance and the binding intensity of electrolyte copper foil are obviously improved.

Abstract: To a certain mortar, the identical measuring means can results in quite difference .Through determination intelligence concrete mortars mechanical –electrical with direct current ,alternating circuit,direct bridge and alternating electric bridge,the authors points out the outcomes stability from direct current and direct bridge get worse because they can´t dispel polarization existed in mortar itself. On the contrarory , both alternating circuit and alternating electric bridge can . At the same time, The authors discussed the influence on impedance (Z) of difference equivalent and frequency, and found that the using of series connection and high frequency sine wave can released impedance Z in this materials.

Abstract: Chemical mechanical polishing (CMP) has been widely accepted in modern integrated circuit (IC) industries and hard disk manufacturing processes, to insure wafer surface with high level of global and local planarity required. In CMP process, temperature rise has two-edged influences: temperature-rise accelerates the chemical activity and the motion of nano-particles contained in the slurry through which material removal ratio (MRR) is enhanced; the other side of the same coin is, however, that it will soften the pad surface and subsequently reduce the MRR. Furthermore, it is found that temperature-rise would cause agglomeration of nano-particles, which would cause the wafer surface defect. The net effects of temperature thus should be under investigation with scrutiny. In an attempt to study the temperature variation and influencing rule, in this paper we firstly establish the flow equation considering pad roughness, coupling the energy equation on the basis of thermodynamics. Then, by taking numerical simulation which is carried out to give out the temperature distribution of conventional CMP process. The results show that temperature-rise in the CMP process is very minor. The research will surely shed some lights on the mechanism of CMP and lay a feasible foundation for possible future utilization.

Abstract: Weight calculation of steel pipe by hand is difficult and apt to be inaccurate .It could be solved easily by Visual Basic programme.The programme is simple and intuitionistic. The efficiency and exactness have been improved greatly.