Key Engineering Materials Vols. 480-481

Abstract: A kind of novel betaine type amphoteric surfactant was synthesized using tetradecylamine and pentaerythritol as the starting material. The structure of bismyristyl bisulpho betaine type amphoteric surfactant was identified by FTIR.The influence factors of the synthesis process were studied.The optimal condition of the synthesis was gained. The results have show that the reaction time and mole ratio (Intermediate / Dimethyl tetradecyl tertiary) were 18 h and 0.5/1 at 135°C. Then it was performed the surface tension tests to determine the critical micelle concentration(cmc).

Abstract: General purpose pitch-based carbon fiber (PCF) was pretreated with steam to develop pores on the surface of fiber. After immersed in cobalt salt solution, PCF was used as raw materials to prepare activated carbon fiber (ACF) through steam activation process. The effect of pretreatment of carbon fiber on specific surface area, mesopore volume and pore size distribution was investigated by N2 adsorption, and morphology of the resultant ACF was observed with scanning electron microscope(SEM). The results show that pretreatment of PCF enlarges specific surface area and mesopore ratio of ACF remarkably. The best ACF obtained in experiment is the one with specific surface area of 2670 m2/g and mesoporosity of 61.8%. Cobalt has evident catalysis in preparing ACF from activation of PCF, while specific surface area and pore size of ACF get smaller with cobalt salt immersion when pretreatment is too strong.

Abstract: In this paper,Palmitic acid-2-hydroxy-3-sulfonic sodium propyl ester was prepared with palmitic acid as main material by steps of sulphonation, saponification and esterification. And optimum reaction conditions of each experiment was investigated, the results showed that the best conditions for sulphonation were n(epichlorohydin):n(sodium bisulfite)=0.87:1, reacted at 85°C for 3.5h,conversion ratio was 80.4%. The optimum reaction conditions of sodium palmitate were n(palmitic acid):n(sodium hydroxide)=1:1, reaced at 85°C for 4.5h, conversion ratio was 83%. Palmitic acid-2-hydroxy-3-sulfonic sodium propyl ester was obtained under optimum conditions of n(3-chloro-2-hydroxy sulfonate): n(sodium palmitate)=1.1:1, reacted at 65°C for 6.5h, conversion ratio of product was 86.82%. The structures of product were characterized by FTIR, and its surface properties were studied: such as critical micelle concentration, surface tension , emulsibility and foamability .

Abstract: A Detection system of Orange shape structure parameters Based on DSP, including its hardware part and software part was introduced. The hardware part equipped with the high performance DSP acts as the core component of the image processing, which provides a guarantee of the real-time of the shape detection. The software part introduces the basic principle of the orange recognition arithmetic, and differentiates by Zernike moments and k-means algorithm. The experiments show it can meet the practical detection requirements that the high detection accuracy of the normal fruit shape and the low-grade fruit shape.

Abstract: Corn fiber is a polymeric fiber made from corn as the raw material. Wide applications have been found for corn fibers in recent years and many progresses on the study of corn fibers have been made as well. The performance of corn fiber is determined by the molecular weight of polylactic acid. Corn fibers have some professional properties, such as high transparency, well-heat-resistant stability, well-coloring, and full biodegradability, as well as the feature in ecological recycle. These means the corn fibers are new-typical and green, full-environmental fibers. The corn fibers can be blended with other fibrin fibers with good hygroscopic to get products of high-performance and low in price. The blending techniques of corn fibers with color cotton fibers and corn fibers with Richcel and lambsdown are studied and developed in this paper and good social and economical benefits have been achieved.

Abstract: In order to find the influence of exercise on the free radical level and the anti- oxidized ability of female elite speed skaters before competition, we measured blood serum GSH-PX, SOD, MDA and ROS of 24 female elite speed skaters' who participated in the "the body is outstanding" nation female elite speed skaters tournament. Research consequence is: the density of female elite speed skaters ' blood serum ROS has the trend of escalation before competition (P<0.05, P<0.01), and the MDA density has the drop tendency (P<0.01, P<0.05); GSH-PX/MDA, SOD/MDA is higher than SOD/ROS, GSH-PX/ROS (P<0.05, P<0.01).

Abstract: The organic-silicon films, polytetrafluorethylene (PTFE) films and its composite films with copper have been fabricated from an active gas phase by pulse laser dispersion from initial powder species. The features of all films obtained were studied with the application of attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Our results suggest that the wavelength of laser radiation impact a strong effect on the molecular structure of all films. Specifically, the peaks corresponding to the detachment of C-H bonds in the organic-silicon films and its Cu doped films at a laser wavelength of 532 nm and the destruction of the Si-O-Si groups at 266 nm due to the ultraviolet radiation have been observed. Interestingly, the concentration of Si-С6Н5 groups relative increases with a decremental of the wavelength of laser radiation. In addition, the PTFE films formed at a laser wavelength of 355 nm presented a lower order degree and high amorphous phase, while PTFE-Cu composite films at laser wavelength 266 nm exhibited enhanced crystallinity due to the presence of copper species, wherein being served as nucleation centers. Remarkably, the wavelengths of laser radiation nearly play no effect on the orderness of PTFE-Cu composite films.

Abstract: In this paper, equilibrium phase diagram in Al-15Si-xCu system piston alloys was calculated using “Pandat” software. The influence of Cu content on the friction and wear behavior of Al-15Si piston alloys at elevated temperature was investigated by the combination use of optical microscopy (OM) and scanning electron microscopy (SEM). Experimental results showed that the abrasive and wear weight and the friction factor in the T6-treated piston alloys were reduced with the increase of Cu content. The friction and wear properties differ slightly in the piston alloys containing 4.5% and 5.5%Cu, which is related to the high thermally stable precipitates, i.e., Q-phase, ε-phase, and θ-phase. For the piston alloys containing low Cu content, the wear mechanism belongs to adhesive wear, while abrasive particle wear is responsible for the high Cu content piston alloys.

Abstract: Chemical composition and physical properties are measured and inspected for China railway grade B cast steel wheel. The wheel shows slight higher for chemical elements C and Cr, much higher for Al and Mo, and significant lower for P and S comparing to the AAR code. Gross pearlites plus net-like continuum ferrites appear in wheel hub; ferrites exhibit also net-likely but dis-continuously in web with a shot peening effect; and in rim, dis-continuous ferrites with few of net-like signs distribute randomly due to a quenching and tempering effect. Bigger hardness values appear in rim; and the values in web and hub appear a decrease in sequence. Major flaw affecting material condense is shrinkage porosities. Flawed content is closely between hub and web. More condense appears in rim. Material inclusions are non-metallic compounds of MnS and Al2O3. They appear sphere-like shapes having around 8 μm diameters.