Advanced Materials Research Vols. 989-994

Abstract: A simple process was developed for preparation of highly photoactive Fe and S codoped TiO₂-SiO₂-ZnO composite film. The Brunauer–Emmett–Teller (BET) surface area results showed that the specific surface area of the composite TiO₂ sample was 432.5m²g^-1, while that of the pure TiO₂ was 103.4m²g^-1. The diffuse reflectance measurements exhibited an extension of light absorption into the visible region for the composite TiO₂. The photoluminescence (PL) spectra analysis indicated that the electron-hole recombination rate was effectively inhibited in the composite TiO₂. The photocatalytic activities of the TiO₂ films were evaluated by the photocatalytic decomposition of methyl green in aqueous solution. The composite TiO₂ film exhibited excellent photocatalytic activities compared to pure TiO₂ film.

Abstract: This study was undertaken to evaluate a new kind of polycarboxylate superplasticizer .Used polyoxyethylene ether (TPEG), acrylic acid (AA) as the monomer, ammonium persulfate (APS) as initiator, thioglycolic acid (TGA) as chain transfer agent, synthesised polycarboxylate superplasticizer with high water reducing rate. The effect of admixtures on fluidity and concrete slump were discussed in this paper. The structure of carboxylic acid water reducing agent was characterized by IR spectra and Gel permeation chromatography.This investigation also evaluated the influence of different serials of polyoxyethylene ether (TPEG), the dosage of acrylic acid (AA) and ammonium persulfate (APS).

Abstract: A new type of amide-modified polycarboxylate superplasticizer was synthesized by a two-step method: Firstly, a mixture of amidated and esterified products reacted by maleic anhydride and 2-aminoethanol was modified through Mannich reaction. Then, the modified product was reacted with Prenyl alcohol polyethenoxy ether (TPEG), acrylic acid and other monomers to obtain an amide-structured polycarboxylate superplasticizer. The molecular weight and molecular weight distribution were measured by Gel permeation chromatography (GPC). Lastly, the optimum AA to modified product ratio, initiator dosage and reaction time were determined by cement mortar test. The concrete application performance showed that the synthesized superplasticizer could improve the fluidity of the concrete and maintain the slump loss as well. The introduction of modified PCE has no harm for the concrete strength.

Abstract: A low carbon content and improved steel making practices have imparted advanced high strength steel (AHSS) CP800 with superior combination of strength, ductility and weldability. Its performance in fatigue, however, is not well understood. Stress-controlled high cycle fatigue (HCF) tests were conducted to obtain stress vs. fatigue life curve (S-N curve), and the fatigue limit of CP800. The follow HCF performances were obtained. , SRI1=1940MPa, b=-0.09972, Nc₁=2.89×10⁶, and R²= 0.88. The collected material data are used as a basis of comparison of CP800 with more common grades of structural steel. CP800 steel shows high strength, comparable ductility, and high fatigue limit level. The test results indicate that compare to that of lower strength common grades of structural steels, CP800 steel has a much higher fatigue endurance limit (say, 476MPa), about 0.6 of its tensile strength (TS). Thus, provides a distinct advantage.

Abstract: Conductive particle fillers could improve the dielectric properties of the polymer matrix. By solvent casting method, different volume fraction of nanosilver particles were added into the PVDF film to prepare Ag/PVDF composite film so as to increase the dielectric properties of the materials. SEM was used to analyze the microstructure of the films. SEM images show that nanoAg filler particles were uniformly distributed throughout the whole matrix of the composite films. Dielectric property tests show that with the increase of nanoAg content, the dielectric constants of the composites increase first and decrease later while the dielectric losses decrease first and increase later. In the case of the optimal 17vol% Ag content, the dielectric constant of the composite film is the highest (14.5 at 100 Hz) with lower dielectric loss, and the energy storage density is relatively high (0.340 J·cm⁻³).

Abstract: To improve the wear properties of AZ91D magnesium alloys, a Cu_0.9NiAlCoCrFe high entropy alloy (HEA) coating was fabricated on AZ91D magnesium alloys by laser cladding using prealloyed Cu_0.9NiAlCoCrFe powders. The microstructure of the HEA coating was characterized by OM, SEM and XRD. The wear resistance of the HEA coating was evaluated under dry sliding wear test condition at room temperature. The results show that the HEA coating mainly consists of a simple BCC solid solution phase. The HEA coating exhibits excellent wear resistance. The main wear mechanisms of the HEA coating and the AZ91D substrate were different, the former dominated by oxidative abrasive wear and the latter suffered from both adhesive and abrasive wear.

Abstract: Plasma emission spectroscopy was used to study the evolution behavior of the Zn ions in the plasma produced by nanosecond pulsed laser beam irradiating on pure zinc metal targets. The measurements indicated that the hotter and denser region in the plasma was located at about 0.75mm from target surface and presented at delay time 250 ns with respect to the laser pulse. Compared to Zn atoms in the plasma expansion, the results reveal that Zn ions are characterized by weaker intensity in spatial profiles and shorter lifetime in temporal evolution, while, much higher brightness of Zn ions can been observed in early-state plasma emission.

Abstract: For study on SO2 and NO emission characteristics of circulating fluidized bed boiler experiments were carried out in a 300MW circulating fluidized bed boiler. In these experiments, the variables were the amount of limestone and bed temperature. While conducting the test, the reasons for the changes in emission were analyzed, and some advices about combustion adjustment were proposed.

Abstract: This article presents a new design of waterproof ground for rest rooms in basements by using new materials and new combination. First use cement mortar to paste the waterproof and heat resistance foam glass furring bricks which have low density and high strength on the ground. Then use silicon sealant to fill the gap between the bricks. Roll brush the multifunctional transparent elastic waterproof coating pure acrylic JQ - 168 on the bricks as surface. The combination of the two formed a sealed waterproof ground in indoor restrooms with certain strength and toughness. So this kind of ground surface can have stable and reliable waterproof function when in face of the situation that groundwater upwelling through fissures in concrete created by resistless damage like earthquake and so on.

Abstract: The influence of minor Mo addition on the lattice misfit and creep rupture strength of a new single crystal superalloy have been investigated. It was shown that Mo can reduce the lattice misfit; increase the tendency of forming TCP phase; extend the time to material failure.