Advanced Materials Research Vol. 800

Abstract: Using Gas Chromatography and Fourier Transform Infrared Spectroscopy (FT-IR), the content of metal impurity element and gas-liquid inclusions in natural crystal and ordinary silica mine of different mining area had been studied. The characteristics of silica mine which was suitable for microwave-acid etching process to remove gas fluid inclusion in quartz sand had been discussed.Our results showed that the silica mine which had low content of impurity, less content of gas-fluid inclusion and high water filling degree was suitable for the microwave-acid etching process to remove gas-liquid inclusion in quartz sand; the content of metal element impurities in quartz sand from Madagascar was nearly close to the primary natural crystal, had less content of gas-fluid inclusion and high water filling degree, and was suitable for the microwave-acid etching process to remove.

Abstract: The tunnel wet dust precipitator (TWDP) is designed and applied to the underground mine tunnel dust control. The TWDP is a modular design with the disc which the radiant fine stainless-steel filament and nozzle. Discs are used in serial in axial direction in the TWDP to lift the collection efficiency, and discs are parallel in a section to enlarge the volumetric flow rate. The TWDP, which is connected with the local fan, is mounted at the discharging mine platform, and the experiment is conducted for its performance testing. Results show that the collection efficiency for respirable dust is above 80%.

Abstract: Most of photocatalytic reaction taken place in a slurry type reactor, which is of poor light utilization and difficulty to recycling of photocatalyst. To overcome these drawbacks, a floating photocatalyst (TiO₂/EP) was prepred by hrothermal method, in which EP(Expanded Perlite) was used as an substrate. Photocatalysts activity was evaluated under UV light using Rhodamine B as the pollutant model. The effect of heating temperature, heating time and dosage of EP on activity of TiO2/EP were Discussed. The results showed 2h and 200°C were the optimal conditions and the dosage of EP has no significant effect on activity of TiO₂/EP. The results of XRD and SEM showed TiO₂ is anatase form, well crystallized and dispersed; its particle size is about 100~150nm. This floating photocatalyst can remove about 97.4% rhodamine B(10mg/L) during 90min under UV light. It has broad prospects for engineering applications.

Abstract: In this paper, physical model and mathematical model of the hot water radiant heating phase change wallboard were built. The heat transfer process of wallboard was simulated to analyze different influencing factors and optimize the design of the hot water heating phase change wallboard. The research results can provide reference and basis to the optimization of low temperature hot water radiant heating phase change wallboard.

Abstract: With the elution curves of glycine and taurine, the ion exchange isotherm parameters of glycine and taurine on D290 anion exchange resin are determined by the inverse method. In this work, with the multi-component competitive ion exchange isotherm and the equilibrium dispersion chromatographic model, the elution curves of glycine and taurine on D290 anionic fixed bed are fitted. The parameters of competitive isotherm are determined, K_tau is 2.55, K_gly is 1.65. The result s showed good agreement between the elute curves fitted by the model and the separation data which confirmed the validity of the model selected.Keywords-taurine; glycine;competitive isotherm;inverse method;

Abstract: According to the principle of dynamic quenching a new ON-OFF fluorescent chemosensor for Cu2+ ions was designed, this chemosensor was composed of sodium dodecyl benzene sulfonate (SDBS), p-tert-butylthiacalix[4]arene (TCA) and perylene through the form of self-assembly in aqueous solution. Addition of Cu2+ ions could result in a quenching of the fluorescence emission of perylene inside micelles, which is ascribed to intramicellar complex-fluorophore electron-transfer or energy-transfer effects induced by the complexation of TCA with the Cu2+ ions.The results of the experiment indicated that: With the condition of TCA/perylene = 1000/1, SDBS concentration was 50mmol/L and pH value above 7, concentration of Cu2+ ion can be linearly determined according to the fluorescence quenching in a certain range.

Abstract: This study was conducted to examine whether negative air ions created by anion-fiber would influence the human physiology and psychology. Dynamic continuous blood pressure and electroencephalogram were examined during a 5-h exposure to negative air ions created by anion-fiber in ten adult healthy volunteers. Physiological experiment research was carried out in environmental science laboratory with the anion-fiber curtain. The concentration of negative ions is above 1300 ion/cm³ and the normal standard is 720 ion/cm³.The results suggest that the dynamic continuous blood pressure and skin temperature could possibly be reduced (P<0.01) and the β index of each region decreased significantly.

Abstract: The plutonium material within the nuclear devices would be aerosolized and cause intense respirable hazards in the scenes of nuclear test and nuclear accident. The assessment of plutonium aerosol resuspension according to the typical radioactive contaminated sites would provide instructional data for the resuspended aerosol fluctuation study and edaphic cleanup, which can remedy the uselessness of aerosol diffusion model in the study of plutonium contaminated regions. The empirical model of plutonium aerosol resuspension is based on the aerophysics, the geognosy and the radiochemistry. This method was applied to analyze the representative plutonium contaminated regions. The results indicate that soil erosion is the intrinsic factor of resuspension process. The resuspended concentrations of plutonium aerosols in nuclear test sites are much less severe than those in the “non-nuclear” test sites (safety shots and simulated nuclear accident tests). Short-term, orders-of-magnitude fluctuations of the airborne concentrations are observed due to the natural and man-made disturbances. After systematic soil cleanup the resuspended plutonium aerosol concentration could fall down to the public allowable level.

Abstract: Artificial sand can be obtained by mixing washed sand formed from the the poor quality of natural sand with high clay content and stone powder formed from processing and screening production by appropriate ratio, Which be applied to C20~C35 ready-mixed concrete. By studying the effect the artificial sand on the properties of fresh concrete and concrete after hardening, the result showed that artificial sand substitute for natural sand as ready-mixed concrete fine aggregate is entirely feasible. Key words: Artificial sand, Ready-mixed concrete, Property