Advanced Materials Research Vols. 971-973

Abstract: Physical and chemical properties of 6 apple varieties were measured to gain the variations. The qualities of apples are important for the consumer. These quality attributes can be described by colour, texture and physical attributes such as size and shape. Individual sugars, organic acids, and vitamin C were quantified in six apple cultivars with same soil, climatic conditions and altitudes. The results showed physical and chemical characterization existed different variance in apple varieties, the variance ranged from 6.1% to 109.05%. Fructose was the most dominant sugar in the different apple cultivars, followed by glucose and sucrose, while malic acid was the principal organic acid.

Abstract: The mixed silane films were obtained on the surface of the Q235 steel sheets by directly immersing in a mixed silane solution containing γ-Glycidoxypropyltriethoxysilane (γ-GPS) and 1, 2-bis (triethoxysilyl) ethane (BTSE), The chemical compositions and microstructures of the films were examined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared spectroscopy (FTIR).The corrosion resistances were investigated by electrochemical measurements and neutral salt spray (NSS) test. The effects of silane films to the epoxy coating were investigated through the adhesive property test. The results showed that the γ-GPS/BTSE mixed silane film could remarkably improve the corrosion resistance of epoxy coating and prolong its service life.

Abstract: According to the monitoring requirements of the national grid, geometry size detection program and detection methods of tower materials are determined, based on the demands of the engineering and field measurement. Digital Caliper and Portable Three-coordinate Measuring Machine are further chosen as the measuring equipment. By the research of quality control method, geometry size data of tower materials are analyzed by histogram and Xbar-R chart. Geometry size detection of tower materials and quality control system's framework and module are preliminarily designed. Ultimately, it can provide the theory basis for that the national grid to realize the monitoring and information system management of the purchase quality of tower materials.

Abstract: The development of a new generation of high performance gas turbine engines requires gas turbines to be operated at very high inlet temperatures, which are much higher than the allowable metal temperatures. Consequently, this necessitates the need for advanced cooling techniques. Among the numerous cooling technologies, the film cooling technology has superior advantages and relatively favorable application prospect. The recent research progress of film cooling techniques for gas turbine blade is reviewed and basic principle of film cooling is also illustrated. Progress on rotor blade and stationary blade of film cooling are introduced. Film cooling development of leading-edge was also generalized. Effect of various factor on cooling effectiveness and effect of the shape of the injection holes on plate film cooling are discussed. In addition, with respect to progress of discharge coefficient is presented. In the last, the future development trend and future investigation direction of film cooling are prospected.

Abstract: This paper study on AC-13 skeleton dense-graded asphalt mixtures by fractal theory, obtaining that both aggregate size and gradation have fractal character. Compared three kinds of asphalt mixture, we found that there was a strong correlation between fractal dimension of aggregate and aggregate size distribution. AC-13 skeleton dense-graded asphalt mixtures were tested. The results show that the aggregate fractal dimension has a good correlation with mixture’s bulk density, mineral aggregate gap rate, percentage of voids and asphalt degree of saturation too. The study is useful for reference to the readers who engage in further study of the fractal theory’s application to asphalt mixtures.

Abstract: Carbon nanotube is one of the strongest materials in nature. Carbon nanotubes (CNTs) are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp² bonds formed between the individual carbon atoms. A multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (GPa). Further studies revealed that individual CNT shells have strengths of up to ~100 GPa, which is in agreement with quantum/atomistic models. Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g/cm³, its specific strength of up to 48,000 kN·m·kg^-1 is the best of known materials, compared to high-carbon steel’s 154 kN·m·kg^-1.

Abstract: Mo-Ni coatings were prepared on Ni alloy by pulse electrodeposition method. The effects of current density, electrodeposition temperature, frequency, duty cycle and electrodeposition time on microhardness of Mo-Ni coating were researched, respectively. Microhardness of Mo-Ni coating increases with the increase of current density, electrodeposition temperature, frequency and electro-deposition time in 17.75 A/dm² ~ 19.25 A/dm². 21 °C~ 25 °C, 1000 Hz ~ 5000 Hz and 10 min ~ 20 min, respectively. Microhardness of Mo-Ni coating decreases with the increase of electrodeposition temperature, electrodeposition time and duty cycle in 25 °C ~ 37 °C, 20 min ~ 30 min and 0.5 ~ 0.9, respectively. In the range of current density from 19.25A/dm² to 20.75 A/dm², microhardness of Mo-Ni coating is neariy constant with the increase of current density. When electrodeposition parameters: current density 19.25 A/dm², electro-deposition temperature 25 °C, frequency 5000 Hz, duty cycle 0.5 and electrodeposition time 20 min, microhardness of Mo-Ni coatin is as high as 707.9 HV.

Abstract: Low-dimensional semiconducting metal oxide nanostructures have gained great interest for developing high performance chemical gas sensors. In this study, we successfully synthesized quasi one-dimensional zinc oxide nanowires via a simple and facile hydrothermal process with zinc acetate dihydrate as precursor and polyethylene glycol as surfactant. The crystalline structures and microstructures of the as prepared samples were investigated by X-ray powder diffraction and field emission scanning electron microscopy, and a possible growth process was discussed in detail. Moreover, thick film gas sensor was fabricated with the as prepared nanowires and its sensing properties to acetylene gas, an important fault characteristic gases dissolved in oil-filled power equipments was measured.

Abstract: Synthesized β-SiAlON based on bauxite (Al₂O₃ in 68wt%) by using combined reduction agents aluminum/carbon, aluminum/silicon were studied. Calculated mass change ratio of the specimens after firing, Examined Phase composition and microstructure of the specimens by using XRD, SEM and EDS, Examined the relative content by using chemical analysis.The results show that: the synthesis mechanism of two combined reduction agents specimens are different, the formation amount of β-SiAlON are different, crystal morphology are not the same, the production costs are different; the end of the reaction temperature are 1500°C, the column β–SiAlONˊz are about 3.

Abstract: This paper investigated the microbial infection of postharvest diseases of Dapingding jujube and cited the symptoms of common rot disease .At the same time, the antibacterial effect of cinnamon oil, natamycin and their composition on Dapingding jujube during the period of storage were studied. The results showed that the preservation inhibitory effect of cinnamon oil was better than natamycin at earlier storage, but just the opposite at later storage, while, the effect of the composition had been very good during the whole storage with higher rate of intact fruit, better fruit firmness and lower cankered index.