Advanced Materials Research Vols. 311-313

Abstract: The catechins composition of tea polyphenols with different extracted methods was analysed by HPLC. The aim is to compare the extraction effect of water-extracting and alcohol-extracting method, the purification effect of solvent extraction and ionic precipitation method. The results indicated that organic solvent extraction method can improve the extraction rate of catechins, especially can increase the content of estered catechins. In the technic of organic solvent extraction, the total content of catechins can effectively be increased by using alcohol extraction. Ion precipitation can enhance the content of gallocatechins，while organic solvent extraction can raise the contents of catechins，EC and estered catechins.

Abstract: Under the protected condition of the purified argon atmosphere, Mo-ZrO₂ cermets were sintered by Mo powder and ZrO₂ powder at 1873K for 2 hours. Mircostructure of cermets were observed by means of XRD, optical microscope and SEM anslysis. Electrical properties of sintered samples with different Mo content and temperature were measured using DC four-electrode method. The results showed that metal phase and ceramic phase were independent of each other. With the reduction of Mo content, Mo metal phase as the continuous network structure is dispersedly distributed in the ceramic phase zone. The electrical conductivity of cermets at room temperature increased with decreaseing of the Mo content. The trend that the high-temperature electrical conductivity of cermets changed with the Mo content is the same as the trend that at the room temperature. When the Mo content is greater than 40%, the high-temperature electrical conductivity increased linearly with increasing temperature. The electrical conductivity of 40mol-% Mo-ZrO₂ reached the peak at 1223K and 1473K.

Abstract: Continuous extrusion foaming of CO₂ gas is an efficient method to produce microcellular. The CO₂ concentration in polymer melt is related to initial bubble morphology. Using video recording in this paper bubble interfacial morphology was studied when the gas was injected into polymer melt . The process of single bubble formation in the static and dynamic polymer melt includes three stages. Screw was more effective for gas breaking up and separating. When mixed in screw channel, and blent in the mixing segment, the dispersion, and diffusion rate of gas into polymer melt were increased largely.

Abstract: Potentiodynamic electrochemical tests and surface analysis technics, such as scanning electronic microscope (SEM), energy dispersive spectrum (EDS) and X-ray diffraction analysis (XRD), were applied to investigate the microstructure and corrosion behavior of Ag-Cu-Zn-Ni alloys in Na2S solution. The results reveal that the α-Ag phase is the main matrix of the studied silver alloys. The second phase of Ag-4Cu-0.3Ni and Ag-3Cu-Zn-0.3Ni/Ag-6Cu-Zn-0.3Ni are respectively CuNi and CuNi(Zn) phases. The second phases of Ag-6Cu-Zn-0.3Ni are well-distributed, which leads to an improvement in the corrosion resistance in Na2S solution.

Abstract: According to LPC Bituminous Mixtures Design Guide, performance of several kinds of additives for high modulus asphalt mixture is evaluated by tests. It has done performance comparison among AC20, Sup20 and EME20 using AH70# asphalt. The results show that high modulus asphalt mixture EME2 has high temperature stability and anti-fatigue capability. The testing results in the article had proved that the existing China-made additives can also meet the requirement of High Modulus Asphalt Concrete (HMAC). The mix design of AC20 and Sup20 was done according to LPC Bituminous Mixtures Design Guide, test results are basically the same as EME20 and meet the design requirement. So it can consider using HMAC which satisfies China’s requirement in China.

Abstract: The fire-resistant properties of FRW fire-retardant particleboard and untreated particleboard had been measured under a heat flux of 75 kW/m² by cone calorimeter (CONE). Through the compare between FRW fire-retardant particleboard and untreated particleboard, the influence on the particleboard by FRW fire retardant had been indicated. The results showed that the indexes of heat release rate (HRR), total heat release (THR) and efficient heat combustion (EHC) etc of FRW fire-retardant particleboard were obviously reduced contrast to the ordinary particleboard, but the char-forming rate had a high increase.

Abstract: An organic–inorganic hybrid perovskite (C₆H₅CH₂NH₃)₂CuCl₄was synthesized successfully by solution method at room temperature and the thin film of (C₆H₅CH₂NH₃)₂CuCl₄ was also prepared by spin-coating on the quartz substrate. The perovskite and the film were characterized with X-ray diffraction (XRD), Scan electronic microscope (SEM), Atomic force microscope (AFM), Fourier transform infrared spectroscopy and Thermo Gravimetric Analyzer. Results show that the obtained perovskite has unique layer structure and good thermal stability with melting point around 243.3°C. And the prepared film appears very smooth, continuous and uniform with a grain size of 0.1μm, highly oriented with the (0 0 l) planes perpendicular to the substrate surface. Its optical photoluminescence spectrum mainly depends on the inorganic part so the bandgap can be tuned by changing the inorganic composition. The carrier mobility is around 0.26cm²V^-1S^-1 , which indicates its potential application in field effect transistor with improved film quality.

Abstract: It provides a new way to solve the worldwide the low-temperature cracking and high temperature rutting distresses of the asphalt pavement, by mixing the composite shape-stabilized phase change material (CSPCM) to asphalt mixture. The effect of CSPCM on the temperature of asphalt mixture is analyzed by the monotonic cooling test, the monotonic heating test and the outdoor simulating cycle test. The results of monotonic cooling and heating tests indicate that mixing CSPCM into asphalt mixture can increase the temperature of asphalt mixture during cooling process and decrease the temperature of asphalt mixture during heating process. It has a temperature damping effect as well. The results of outdoor simulation test shows that mixing CSPCM into asphalt mixture decreases the maximum temperature of the bottom of the specimen and increases the minimum temperature of the bottom of the specimen. It cannot change the critical temperature occurring time of the bottom of the specimen. The test results indicate that mixing CSPCM into asphalt mixture could actively adjust the working temperature of asphalt mixture, prolong the ideal temperature of asphalt mixture and improve asphalt mixture’s adaptability to the changing environment.

Abstract: A large-sized high-quartz translucent porcelain plate was developed, which has good decorative effect and market prospects. The light transmittance of the high-quartz translucent porcelain plate (Its thickness: 3.6mm) reaches 0.72%. Compared to other large-sized translucent plates, large-sized high-quartz translucent porcelain plates have obvious advantages about mechanical properties, glossness and the price.

Abstract: For the instability problem of gravity dam sliding along base surface, cubic nonlinear constitutive model of soft material in base surface is adopted, which is usually expressed by Weibull model. Dynamic Equations of dam sliding along base surface is established. By means of catastrophe theory, the jumping and hysteresis phenomena of the vibration amplitude of the dam is analyzed, the parameter range of stable region in which amplitude doesn’t happen catastrophe is given and the factors which cause amplitude instability are discussed. The results obtained in the paper are of significant value for understanding the sliding instability mechanism of gravity dam under earthquake, as well as guiding the design of gravity dams.