Advanced Materials Research Vols. 641-642

Abstract: The staining effects of two staining methods of acetylcholinesterase isozymes were compared . One using acetylthiocholine iodide , K3[Fe(CN)6] and CuSO4 was named as AFCu method, and the other one using acetylthiocholine iodide , K3[Fe(CN)6] and FeCl3 was named as AFFe method. The staining effect of former was better.

Abstract: 1,1-Bis(hydroxymethyl)cyclopropane was synthesized by reaction dibromoneopentyl glycol with zinc powder at mole ratio of nDG:nzinc=1:1.05 and 80oC (slightly reflux) for 7 hours. Under optimal conditions, yield and purity of the title compound were 87.3% and 98.67%, respectively. Dibromoneopentyl glycol was also prepared in 91.7% yield with pentaerythritol and hydrobromic acid as material and diethyl sulfate as catalyst under reflux for 10 hours. Structural characterization of 1,1-bis(hydroxymethyl)cyclopropane was conducted by IR and H-NMR.

Abstract: This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO₂ nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO₂ nanotube arrays, and compared to undoped TiO₂ nanotube arrays Br doped TiO₂ nanotube arrays had better photocatalytic properties.

Abstract: Changes of oxidative stress and antioxidant system were studied in leaves of Ginkgo biloba exposed to elevated CO₂ and O₃ fumigation (2006-2008), and released the gases fumigation for the natural recovery in open-top chambers (OTCs) during the growing season in 2009. Elevated CO₂ had no significant effect on hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents, and the activities of antioxidant enzymes in leaves of G. biloba during the gas fumigation in 2008. Elevated O3 increased significantly H₂O₂ and MDA contents, especially after 90 days of gas fumigation. The adverse effect or damage of elevated O₃ on trees during the gas fumigation was also alleviated by the released-O₃ exposure during the natural recovery. The antioxidative enzyme including superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities showed higher levels under the natural recovery than under the gas fumigation, which may be a helpful response to scavenging reactive oxygen species (ROS). The results also indicated that future alleviating the emissions of CO₂ and O₃ would differentially affect the antioxidant system in plants.

Abstract: We compared the differences in photosynthesis of four urban tree species (Ginkgo biloba, Pinus tabulaeformis, Quercus mongolica and Pinus armandii) exposed to long-term elevated CO₂ (700 ppm) and/or O₃ (80 ppb) fumigation in (open top chamber) OTC. Our results suggest that elevated CO₂ alleviated the damaging influence of elevated O₃ on photosynthesis in the four urban tree species. Both Q. mongolica and P. armandii showed photosynthetic acclimation after long-term treatment under elevated CO₂. The combined effect of elevated CO₂ and O₃ caused the changes including net photosynthetic rates (Pn), stomatal conductance (gs) and chlorophyll content that were more similar to ambient air (CK) or slightly lower than elevated CO₂, indicating that elevated CO₂ is able to totally or partly alleviate the harmful effects of elevated O₃ on urban tree species.

Abstract: CBM has the largest reserve except for conventional natural gas and is the cleanest energy. However, neither coal seam permeability nor CBM vertical well productivity has been determined when the immigration of coal dust are considered, which restricts the economic CBM exploitation. Based on coal seam characteristics, use permeability parallel path model and CBM seepage equation. The results show that with different ratio of non-clogging path and the total path, coal seam permeability and CBM vertical well productivity may either increase or decrease.

Abstract: Using heterogeneous Fenton system dynamic method, a decolorization test was operated for three kinds of simulated dye wastewater (Reactive Red KE-3B, Reactive Yellow KE-4R and Reactive Blue KN-R). Through the single factor experiments to examine the pH, H2O2 dosage, catalyst dosage, reaction temperature and residence time of simulated dye wastewater effected on the simulated dye wastewater decolorization rate. Determined the best decolorization reaction conditions as pH value of 4, the H2O2 concentration of 800 mg/L, catalyst dosage of 20 g, reaction temperature of 60 °C and reaction residence time of 9 minutes. Under this reaction conditions, in heterogeneous fenton system, degradation rate of the three kinds of simulated wastewater reached 95.01%, 93.86% and 97.74%, respectively.

Abstract: Chromatography has found an increasingly wide utilization in scientific and technological fields, even in some cases, has become indispensable methods for analysis and separation. Compared with its application, some common queries in chromatography still lack for good theoretical explanations, for instance, the action of flow rate of mobile phase on symmetry of peak. As is familiar to people, an increase in flow rate of mobile phase always causes theoretical plate number to decrease under normal conditions. At the same time, maybe the symmetry of chromatographic peak obviously increases, on the contrary. This result is self-contradictory. Why does the theoretical plate number not increase under the condition Utilizing our prior paper on five plate numbers in chromatography, this paper points out why theoretical plate number decreases with an increase in symmetry of peak when flow rate of mobile phase increases. Based upon gas-solid chromatography results, the relation between flow rate of mobile phase and frequency of partition of solute, and the relation between flow rate and plate number are deduced. From the angle of theoretical model, this paper discusses the relation between solute partition in static mobile phase such as partition between two phases in plate theory and solute partition in flowing mobile phase such as Martin-Synge partition in slip mechanism, and their characteristics.

Abstract: Well-aligned carbon nanotubes were synthesized in a horizontal furnace using acetylene as the carbon source and argon as the carrier gas through by AAO templates. To cut the upper parts of CNTs out of the template, the temperature of the furnace was first cooled to 350 °C under an argon atmosphere, and the temperature of 350 °C was remained for 5 min under an air atmosphere, then the furnace was cooled to room temperature in air. The as-prepared aligned CNTs were also carefully scratched from the substrate and some of them were placed on a copper grid for high resolution transmission electron microscopy (HRTEM) observations. The morphology of CNTs was examined by scanning electron microscopy (SEM). The results show that well-aligned carbon nanotubes were obtained and the carbon nanotubes on the surface of AAO templates were cut off successfully.