原油降解菌株Pseudomonas sp.6-1B 趋油性迁移特征

引言烃降解微生物接触烃类有3种方式[1]:一是主动接近并附着在大分子烃类物质上,利用细胞膜上的烷烃加氧酶改变烃类性质;二是产生表面活性剂类物质将石油烃乳化成小液滴,进而靠主动运输摄取交换;三是直接将大分子烃类物质运输至胞内利用。无论以哪种方式,能主动与原油接触的微生物     

微生物降解原油发酵液中低分子量有机酸的测定

本文使用气-质联用仪对微生物降解原油发酵液中低分子量有机酸进行测定。采用水蒸汽蒸发法蒸出发酵液中低分子量有机酸，从而使其与样品中大量的无机盐和表面活性剂分离，浓缩后直接进样。该方法简单直接，可以减少有机酸的损失。     

Aging of polyamide 11. Part 1: Evaluating degradation by thermal,mechanical, and viscometric analysis

Hydrolytic degradation at elevated temperatures is a key reason for failure in offshore flexible risers. In this article, the aging of polyamide 11 in deoxygenated water at 90°C and 120°C was studied. Tensile and dynamic mechanical thermal analysis tests were performed to measure changes in mechanical properties. Viscometry, gravimetric measurements, differential scanning calorimetry, and thermogravimetric analysis were used to link these properties with morphological changes. General trends are increased stiffness, tensile strength, and glass transition temperature as well as decreased glassy state damping efficiency with increased aging times. Changes can be initially ascribed to plasticizer depletion and then to interplay between molecular weight decrease and crystallinity increase. Viscosity at hydrolysis equilibrium indicates that brittle failure typically involves oxidation or UV exposure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41971.     

Identification of Turkish extra virgin olive oils produced in different regions by using NMR (1H and 13C) and IRMS (13C/12C)

Isotope ratio mass spectroscopy (IRMS) and nuclear magnetic resonance (NMR) spectroscopy techniques are two of the analytical methods that are used to characterize food products. The aim of this study is to classify extra virgin olive oil (EVOO) samples collected from different regions of Turkey based on ¹H and ¹³C NMR spectra along with IRMS δ¹³C carbon isotope ratio data by using chemometrics multivariate data analysis methods. A total of 175 EVOO samples were analyzed in 2014/15 and 2015/16 harvest seasons. Multivariate classification and clustering models were used to identify geographical and botanical origins of the EVOOs. IRMS results showed that there was no significant difference in terms of δ¹³C values between the years in terms of harvest year (p > 0.05), only extraction phase and variety were statistically significant factors (p < 0.05). The interactions of the factors showed that the harvest year × variety interaction is important. The outcomes of this research clearly indicated that considering the partial least squares discriminant analysis result with NMR spectra, the percent success of the model in the South Marmara, North Aegean, and South Aegean region samples were 95%, 95.7%, and 96.4% in the model set, respectively. The results showed that by using classification and clustering models, geographic marking and labeling of these oils can be carried out regardless of differences in year and production systems (2 and 3 phase extraction system) according the NMR analysis.