基于荧光法和多元回归分析的混合海藻识别方法研究

钱对单一海藻和混合海藻进行荧光激发光谱的二阶导数分析,发现它们的峰值点和谷点有很强的相似性.因此,用二阶导数荧光发射光谱的谷点和峰值点为特征点,取特征点对应的荧光发射光谱的相对强度的归一化数据为特征参数,进行混合海藻的线性多元回归分析,得到分配系数矩阵.去掉分配矩阵中的负分配系数和相对很小的分配系数,重新进行多元线性回归分析,直到达到目标模型为止,这样可以根据剩余的分配系数得到混合海藻中的单一海藻类目.     

STABLE ISOTOPE ANALYSIS REVEALS ANTHROPOGENIC EFFECTS ON FISH ASSEMBLAGES IN A TEMPERATE RESERVOIR

Effluent from anthropogenic inputs can affect fish assemblages in aquatic ecosystems by altering species richness, diversity and trophic structure. To investigate the effects of a bleached kraft pulp mill effluent (PME) and municipal sewage treatment plant (STP) discharge on fish assemblages in a temperate reservoir, we combined standard ecological methodologies with stable isotope analysis of δ¹³C and δ¹⁵N. Total catch, species richness, diversity and coefficient of community loss indicated lower species richness and diversity at sites exposed to PME, whereas sewage‐exposed assemblages had intermediate richness and diversity relative to reference sites. Stable isotope analysis of δ¹³C and δ¹⁵N revealed that many species fed at higher relative trophic positions in the presence of both effluents and showed shifts towards increased reliance on littoral‐derived and benthic‐derived carbon at sites downstream of the PME discharge. Fishes at PME‐influenced sites had also generally higher condition factor whereas fishes at STP‐influenced sites were more variable in condition factor. These differences may, in part, be due to decreased species diversity at these sites and to nutrient enrichment manifest from the effluent discharge. While standard fisheries and ecological methodologies and stable isotope analysis have been separately used in other studies of anthropogenic effects on fishes, their integration in this study provides greater resolution than either could alone. Copyright © 2011 John Wiley & Sons, Ltd.     

Characterizing Soy Sauce Moromi Manufactured by High‐Salt Dilute‐State and Low‐Salt Solid‐State Fermentation Using Multiphase Analyzing Methods

Present study was to characterize the physiochemical properties, free amino acids (FAAs), volatiles and microbial communities of various moromi, respectively sampled from different stages of high‐salt dilute‐state (HSDS) and low‐salt solid‐state (LSSS) fermentation, using multiphase analyzing methods. Phospholipid fatty acids (PLFA) analysis indicated that Gram‐positive bacteria were dominant bacteria and fungi were principal microbes. For DGGE analysis, dominant microbes in moromi were mainly fell into Weissella, Tetragenococcus, Candida, Pichia, and Zygosaccharomyces. During fermentation, the dominant microbes shifted from nonhalophilic and less acid‐tolerant species to halophilic and acid‐tolerant species. Total of 15 FAAs and 44 volatiles were identified in moromi, mainly Glu, Asp, Tyr, and acids, alcohols, esters, aldehydes, respectively. Odor activity values analysis suggested that the final moromi of LSSS fermentation had more complicated odors than that of HSDS fermentation. Conclusively, technological parameters, microbial communities, raw materials and fermentation process may result in the discrepancy of HSDS and LSSS moromi.     

Specific inhibition of biohydrogen-producing Clostridium sp. after dilute-acid pretreatment of sunflower stalks

Dilute-acid pretreatments are commonly used to solubilize holocelluloses of lignocellulosic materials and represent a promising route to enhance biohydrogen production by dark fermentation. Besides the soluble sugars released, furan derivatives, such as furfural and 5-HMF, as well as phenolic compounds can accumulate in dilute-acid hydrolyzates and that may affect fermentative microbial populations. In this study, biohydrogen production from glucose (5 g VS L⁻¹) in batch tests was investigated in presence of increasing volumes (0% – control, 3.75%, 7.5%, 15% and 35% (v/v)) of dilute acid hydrolyzate generated from sunflower stalks (170 °C, 1 h, 4 g HCl/100 gTS). A sharp decrease of the hydrogen yield was observed from 2.04 mol H₂ mol⁻¹_{eq. hexose initial} in the control to 0 mol H₂ mol⁻¹_{eq. hexose initial} for volumes higher than 15% of added hydrolyzate. Although acetate and butyrate were the main end-products found in the control, ethanol and lactate accumulated accordingly with the increasing addition of hydrolyzate. A clear shift of dominant microbial populations from Clostridium sp. to Sporolactobacillus sp. was concomitantly observed, suggesting a specific inhibition of the biohydrogen-producing bacteria by adding increasing volumes of hydrolyzates.     

How the online social networks are used: dialogues-based structure of MySpace

Quantitative study of collective dynamics in online social networks is a new challenge based on the abundance of empirical data. Conclusions, however, may depend on factors such as user''s psychology profiles and their reasons to use the online contacts. In this study, we have compiled and analysed two datasets from MySpace. The data contain networked dialogues occurring within a specified time depth, high temporal resolution and texts of messages, in which the emotion valence is assessed by using the SentiStrength classifier. Performing a comprehensive analysis, we obtain three groups of results: dynamic topology of the dialogues-based networks have a characteristic structure with Zipf''s distribution of communities, low link reciprocity and disassortative correlations. Overlaps supporting ‘weak-ties’ hypothesis are found to follow the laws recently conjectured for online games. Long-range temporal correlations and persistent fluctuations occur in the time series of messages carrying positive (negative) emotion; patterns of user communications have dominant positive emotion (attractiveness) and strong impact of circadian cycles and interactivity times longer than 1 day. Taken together, these results give a new insight into the functioning of online social networks and unveil the importance of the amount of information and emotion that is communicated along the social links. All data used in this study are fully anonymized.     

Replacement of Diesel Generator Sets in Isolated Communities with More Efficient Biomass Combustion Process

Electrical power supply to communities isolated from urban areas is typically complex and expensive. Their geographical situation and the lack of infrastructure and qualified workforce impede the provision of electricity. Many are the sources of energy available, but few are appropriate or sustainable. Combustion of diesel fuel is a good technical solution; however, it is neither economic nor environmentally tenable. This paper presents the advantages of using biomass as an energy source, along with its potential increase in efficiency when steam is generated in specific circumstances of temperature and pressure.     

对原水中藻类及嗅味的去除

本文主要介绍了给水系统中藻类产生嗅味的种类,及藻类与嗅味的去除和控制方法。     

从“树形”到“互动网络”——公交引导下的村镇社区空间发展模式初探

公共交通导向(TOD)的村镇社区空间发展模式,是基于东部沿海平原省份城乡公路与道路网络较为发达的地域特性,通过选择性地建设设置公交站点的"城镇型社区",形成网络化互动连接的城乡公交体系及公共服务设施体系,进而触发城乡要素流动、优化公共服务,改变传统发展动力自上而下的树形结构模式。通过对德州市临邑县村镇体系规划的实践研究,发现TOD村镇社区空间发展模式能够在依托地域需求、服务政府决策、优化规划模式和改善功能结构等方面为我国的新农村规划建设提供参考。     

Study on Microbial Communties during the Fermentation Process of Feng ＆ Composite-flavor Taibai Liquor（II）：Microbial Communities in Fermented grains

对凤兼复合型太白酒发酵过程中糟醅微生物区系的多样性、构成及演替规律进行研究,并通过形态、生理学特性的分析比较和16S rRNA基因序列分析,对发酵过程中主要微生物类群进行了分类鉴定。     

New nitrogen-containing bromophenols from the marine red alga Rhodomela confervoides and their radical scavenging activity

In addition to nine known bromophenol derivatives, five new nitrogen-containing bromophenols were isolated from an ethyl acetate extract of the marine red alga Rhodomela confervoides. By using spectroscopic methods, the structures of the new compounds were identified as 3-(2,3-dibromo-4,5-dihydroxybenzyl)pyrrolidine-2,5-dione (1), methyl 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoate (2), 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoic acid (3), 3-bromo-5-hydroxy-4-methoxybenzamide (4), and 2-(3-bromo-5-hydroxy-4-methoxyphenyl)acetamide (5). All of these bromophenols showed potent scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals, with IC(50) values ranging from 5.22 to 23.60μM. These compounds also displayed moderate activity against ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radicals, with Trolox Equivalent Antioxidant Capacity values (TEAC) ranging from 2.11 to 3.58mM. The results obtained in this study demonstrate that the bromophenols obtained from R. confervoides may have potential application in food and/or pharmaceutical fields as natural antioxidants.