Taxonomic diversity of fish community in the waters surrounding the Taishan Islands of Fujian Province

根据2012年~2013年在台山列岛周边海域进行的4个航次底拖网调查资料,并结合该海域的历史资料系统整理了台山列岛周边海域鱼类总名录,使用PRIMER 5.0软件计算了该海域鱼类的分类多样性指数,研究了分类多样性指数的季节变化。结果显示,台山列岛周边海域共记录鱼类2纲20目81科150属208种,以鲈形目种类占绝对优势;2012年~2013年调查记录到鱼类2纲11目40科63属77种。台山列岛周边海域鱼类的平均分类差异指数(△~+)和分类差异变异指数(∧~+)的理论平均值分别为63.14和378.4。鱼类分类多样性指数(△)秋季最高,春、夏季次之,冬季最低;鱼类分类差异指数(△~*)秋季最高,春季次之,夏、冬季较低。研究结果表明,春季鱼类种类数最多,夏、秋季次之,冬季最少,水温和饵料决定了研究海域鱼类种类组成。According to the data collected from four seasonal trawling surveys between 2012 and 2013 in the waters surrounding the Taishan Islands,we made a list of fish species in this area and calculated its taxonomic diversity by PRIMER 5. 0. We identified 208 fish species including 2 classes,20 orders,81 families and 150 genera in the waters around Taishan Islands,with Perciformes being the major order. According to the survey data from 2012 to 2013,77 fish species including 2 classes,11 orders,40 families and 63 genera were identified. The average taxonomic distinctness( △~+) and variation in taxonomic distinctness( ∧~+) of fish species listed in that area were 63. 14 and 378. 4,respectively. The taxonomic diversity( △) and taxonomic distinctness( △~*) were higher in autumn and spring than in summer and winter. It is concluded that the species in spring was more than that in summer and autumn,and was the least in winter. Water temperature and food were the main factors which affect fish species composition.国家自然科学基金项目(41106073);; 福建省科技计划项目(2012Y0072);; 福建省海洋与渔业厅科技项目[(2012)013号

Density functional theory study of CHx (x=1-3) adsorption on clean and CO pre-covered Rh(111) surface

CHx (x=1-3) species, central in many catalytic reactions occurring on transition metal surfaces, have been extensively studied from both of experimental and theoretical points of view. Among them, rhodium is a unique catalyst due to its high selectivity and activity for the synthesis of higher oxygenated compounds, especially in methane partial oxidation to syngas and subsequent C2-oxygenates. Although significant efforts have been pursued on the experimental characterization of small hydrocarbons on Rh surfaces, there are still many remain. For example, in CO hydrogenation over promoted Rh catalysts it is widely accepted that during the formation of C2-oxygenates, CO is inserted into the surface-alkyl group and generates CHxCO species. There is, however, no agreement on which CHx species will be inserted by CO. [1-2] To unravel the microscopic mechanisms, it is mandatory to study the elementary steps for insertion which begins with co-adsorption of CHx and CO on these surfaces, and studied by density functional theory calculations.[3] It is found that CHx (x=1-3) radicals prefer three-fold hollow sites on Rh(111) surfaces, and the bond strength between CHx and Rh(111) follows the order of CH3 < CH2 < CH. When the coverage is larger than 1/4 ML, considerable repulsion is built up between adsorbates. We find that surface work function decreases after CHx adsorption due to charge transfer from the radicals to the substrate. For adsorbed CH3, charge back donation from the substrate to C-H bond is identified and results in C-H stretch mode-softening. The mode-softening is however prevented by co-adsorbed CO via charge competition. Conversely, C-O stretch is softened by enhanced backfilling of anti-bonding states of five sigma orbital from the CH3. Finally, the C 1s surface core level shifts (SCLS) for CHx with and without the presence of CO are calculated, and compared with experiments

Assessment on the vulnerability of Luoyuan Bay ecosystem, Fujian

本研究以"暴露程度-敏感性-适应能力"为框架,构建了罗源湾海湾生态系统脆弱性评价指标体系,并运用模糊综合评价法对罗源湾海湾生态系统在1986~1; 990、2004~2006、2010~2012年三个阶段的脆弱性状况开展了定量评价,结果显示,罗源湾海湾生态系统在三个阶段均处于"中度脆弱"水平; ,综合评价得分逐年上升,呈现渐脆弱趋势.三个子系统的模糊评价结果表明,罗源湾海湾生态系统面临的暴露程度不断增大,其主要人为胁迫因子为滩涂围垦面积; 、临港工业发展和海水养殖密度;其次,罗源湾海湾生态系统的敏感性也越来越强,主要的敏感因子有海洋生物质量综合指数、浮游动物和潮间带底栖生物多样性指; 数和鱼卵仔稚鱼种类与密度;与此同时,适应能力则呈较好态势.研究结果可为相似区域海湾生态系统脆弱性评价提供参考.Based on the "Exposure- Sensitivity- Ability to adapt" framework, the; vulnerability assessment index system was established for Luoyuan Bay; ecosystem. The ecosystem vulnerabilities in 3 periods (1986~1990,; 2004~2006, 2010~2012) were studied used the fuzzy comprehensive; evaluation method. The results showed that all 3 periods were in; "mild-vulnerability". The scores increased in years and Luoyuan Bay; ecosystem tended to be increasingly vulnerable. The evaluate results of; 3 subsystems showed that the exposure intensity of Luoyuan Bay ecosystem; was increasing and the major artificial stress factors were reclamation; areas, port industry developments and aquaculture density. And the; sensitivity of Luoyuan Bay ecosystem was obviously intense, the main; sensitive factors were comprehensive index of marine life quality,; biological diversity indexes of zooplankton and intertidal benthic, and; species and density of fish larvae and eggs. Meanwhile, the adaptive; capacity of Luoyuan Bay ecosystem presented a good tendency. This; research can provide a reference for the vulnerability assessment of bay; ecosystem in similar regions.农业部2014年物种资源保护(渔业)资助项

MCM-22分子筛酸性的DFT理论计算研究

本文利用量子力学中的密度泛函理论（DFT）计算，研究了MCM-22分子筛上骨架Al在8个不同的T位的分布和Broensted酸的落位及强度。所有计算基于分子筛的8T簇模型（H3SiO)3Si-O（H)-T（OSiH3)3（T=Si，Al)，采用DFT的BLYP方法，所有原子均应用DNP基组。通过计算（Al，H)／Si替代能和质子亲和势，得出推论：MCM-22分子筛中骨架Al的最有利落位在T1，T4，T3和T8位。而形成Broensted-酸的最可能的位置为Al1-O3-Si4，Al4-O3-Si1，Al3-O11-Si2和Al8-O10-Si2桥基。Al1-O3H-Si4和Al4-O3H-Si1位的酸性强度接近，Al3-O11H-Si2和Al8-O10H-Si2位的酸性分别略低于和略高于前两个酸位。通过计算模板剂分子六次甲基亚胺(HMI)与B-酸中心的相互作用，进一步探讨了HMI对分子筛中Al落位的靶向作用