Contents and Distribution of Petroleum Hydrocarbons (PHC) in Jiaozhou Bay Waters

Based on data from the investigation in Jiaozhou bay waters in 1979, the distribution, pollution source and seasonal variation of PHC in Jiaozhou Bay are analyzed. It is showed that in Jiaozhou bay PHC contents arrived the national Category Ⅱof the water quality standard during this year. In summer in the bay the pollution of PHC was heavy, while relatively light in spring. In the coastal waters in the east and the northeast of the bay, the PHC contents in spring surpassed the national Category Ⅱ, and surpassed the national Category Ⅲ. In the coastal waters, in the northeast of the bay, the change of the PHC contents formed the grads: the contents presented the falling trend from the big one to the small, which unveiled that the PHC souce in the bay mainly came from the discharge of the industrial waste water and living sewage.

Effects of Different Processing Methods on Chlorogenic Acid Content in Fructus Gardeniae

[Objective] This study aimed to compare the effects of different processing methods on the content of chlorogenic acid in Fructus Gardeniae. [Method] The chromatographic separation was performed on an Inersil ODS-2 C18column(250 mm × 4. 6 mm,5 μm) with acetonitrile- 0. 1% acetic acid solution(12∶ 88,V/V) as the mobile phase under conditions of flow rate 1. 0 ml/min,detection wavelength 327 nm,column temperature 25 ℃. [Result]With a range of0. 42- 2. 52 μg / μl,chlorogenic acid concentration exhibited a good linear relationship with peak area( n = 6,R = 0. 999 9). The average recovery rate was100. 83%,RSD was 1. 30%. [Conclusion] The established method is convenient,rapid and accurate with good repeatability,which can be used to effectively control the quality of different processed products of Fructus Gardeniae.

Effect of C/N Ratio on DHA Production by Schizochytrium sp.JN-3 and Its Pilot-scale Fermentation

[Objective] This study aimed to explore the effect of C/N ratio on DHA production by Schizochytrium sp.,and the results were verified by pilot-scale fermentation.[Method] Effect of C/N ratio on DHA production by Schizochytrium sp.JN-3 was explored.The industrial fermentation potential of Schizochytrium sp.JN-3 was investigated by pilot-scale fermentation in a 200 L fermentation tank.[Result] Results of fermentation in a 7 L fermentation tank showed that the maximum biomass and total lipid content were 34.3 and 20.1 g/L,respectively,when C/N ratio was 10;the maximum DHA yield was 46.9% when C/N ratio was 20.When pilot-scale fermentation was conducted in a 200 L fermentation tank,the biomass was 30.2 g/L,total lipid content was 18.4 g/L,accounting for 63.2% of the dry weight of cells;DHA content was 7.4 g/L,accounting for 40.2% of the total lipid content.[Conclusion] Schizochytrium sp.JN-3 has good industrial fermentation potential.

Formation mechanisms of Ti_(3)(Si,Al)C_(2)/Al_(2)O_(3) composites from Ti_(3)AlC_(2) and SiO via low-temperature sintering

Ti_(3)SiC_(2)/Al_(2)O_(3) composites have attracted attention due to their excellent mechanical and electromagnetic properties,but the high temperatures(≥1400℃)required for the densification of aluminum oxide(Al_(2)O_(3))leads to the decomposition of Ti_(3)SiC_(2).To address this issue,Ti_(3)(Si_(x)Al_(1−x))C2/Al_(2)O_(3)(x represents the Si content)composites were synthesized for the first time via hot-pressing(HP)sintering and current-assisted sintering(CAS)of mixed Ti_(3)AlC_(2) and silicon monoxide(SiO)powders at 1300 and 1200℃,respectively.Both approaches produced composites with x values greater than 0.9,indicating that the compositions of the prepared composites were similar to those of Ti_(3)SiC_(2)/Al_(2)O_(3) composites.The synthetic mechanism involved substitution and continuous interdiffusion of Al and Si atoms.The composite prepared by CAS at 1200℃ was compacted,whereas the composite prepared by HP had a low density.The low-temperature densification mechanism is attributed to the combined effects of amorphous SiO,liquid Al,and the high heating rates for CAS.The flexural strength and hardness of the composite prepared by CAS were also comparable to those of compacted Ti_(3)SiC_(2)/Al_(2)O_(3) composites.