A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period...A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components （14：0, 16：0, 16：1, 18：1 and 20：5）, and n-alkanes （C16-C23） were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017-0.024 d^-1, 0.049-0.103 d^-1 and 0.011 to 0.069 d-l, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments.展开更多
This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Ch...This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Chinese non-English majors＇ learning styles and their learning strategies in English study, and to analyze the impact of learning styles on learning strategy preferences statistically so as to provide empirical evidence in this field, and then present some implications for college English teaching and learning in Chinese context. This study has significance for pedagogy. Teachers should make language learners aware of their own learning styles and strategy preferences and help them select strategies matching their own style preferences in second language learning. It is hoped that this study can benefit language teachers, learners, and researchers to some extent and can spark more teaching research in the future.展开更多
In this paper, we introduce the concept of the general butterfly graph B[m,n;d] for integers m,n ≥ 3, d ≥ 1, determine its balance index set, and give the necessary and sufficient condition for balanced graph B[m,n;...In this paper, we introduce the concept of the general butterfly graph B[m,n;d] for integers m,n ≥ 3, d ≥ 1, determine its balance index set, and give the necessary and sufficient condition for balanced graph B[m,n;d] to exist.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 40476038 and 40576039)
文摘A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components （14：0, 16：0, 16：1, 18：1 and 20：5）, and n-alkanes （C16-C23） were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017-0.024 d^-1, 0.049-0.103 d^-1 and 0.011 to 0.069 d-l, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments.
文摘This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Chinese non-English majors＇ learning styles and their learning strategies in English study, and to analyze the impact of learning styles on learning strategy preferences statistically so as to provide empirical evidence in this field, and then present some implications for college English teaching and learning in Chinese context. This study has significance for pedagogy. Teachers should make language learners aware of their own learning styles and strategy preferences and help them select strategies matching their own style preferences in second language learning. It is hoped that this study can benefit language teachers, learners, and researchers to some extent and can spark more teaching research in the future.
基金the National Natural Science Foundation of China （No. 10671005） the Natural Science Foundation of Hebei Province （No. A2007000230）.
文摘In this paper, we introduce the concept of the general butterfly graph B[m,n;d] for integers m,n ≥ 3, d ≥ 1, determine its balance index set, and give the necessary and sufficient condition for balanced graph B[m,n;d] to exist.
