8-羟基喹哪啶固相萃取光度法测定生物样品中的钴

研究了8-羟基喹哪啶与钴的显色反应,在pH为8.0的氯化铵—氨水缓冲介质中,乳化剂-OP存在下,8-羟基喹哪啶与钴反应生成3∶1稳定的蓝紫色配合物,该配合物可被Waters Plus-C18固相萃取小柱萃取富集,小柱上富集的配合物用乙醇为洗脱剂洗脱后用光度法测定,在乙醇介质中,配合物最大吸收波长λmax为595 nm,ε为7.82×103L.mol-1.cm-1。钴含量在0.1~5.0 mg/L内符合比耳定律,方法用于生物样品中痕量钴的测定,结果令人满意。     

Forest cover change and fragmentation using Landsat data in Maçka State Forest Enterprise in Turkey

In this study, Grey model (GM) and artificial neural network (ANN) were employed to predict suspended solids (SSeff) and chemical oxygen demand (CODeff) in the effluent from a wastewater treatment plant in industrial park of Taiwan. When constructing model or predicting, the influent quality or online monitoring parameters were adopted as the input variables. ANN was also adopted for comparison. The results indicated that the minimum MAPEs of 16.13 and 9.85% for SSeff and CODeff could be achieved using GMs when online monitoring parameters were taken as the input variables. Although a good fitness could be achieved using ANN, they required a large quantity of data. Contrarily, GM only required a small amount of data (at least four data) and the prediction results were even better than those of ANN. Therefore, GM could be applied successfully in predicting effluent when the information was not sufficient. The results also indicated that these simple online monitoring parameters could be applied on prediction of effluent quality well.     

龙眼miR167家族分子特性及其潜在靶标在体胚发生早期的表达模式

为了解miR167家族成员的分子特性及其可能互作的靶标在龙眼体胚发生早期的调控机制,采用生物信息学分析方法进行龙眼miR167基因家族序列分析、二级结构预测、分子进化树分析、靶基因预测及其靶标特异表达的FPKM值分析,并采用实时荧光定量PCR技术(quantitave real-time PCR,qPCR)检测miR1...     

近30年来鄱阳湖环湖区土地利用与景观格局变化研究

以1988—2018年7期Landsat遥感卫星影像为数据源,采用土地利用转移矩阵、景观格局指数等方法探究了鄱阳湖环湖区近30年来土地利用与景观格局变化特征.结果表明：(1)近30年来鄱阳湖环湖区建设用地和林地面积显著增加,耕地、草地、水域和未利用地面积减少.(2)建设用地的转入类型以耕地为主,30年间共侵占耕地面积1243.66 km²,占建设用地面积增加量的71.19%.林地的转入类型主要为耕地和草地,其中,耕地转入占比56.95%.耕地的转出类型以建设用地、草地和林地为主,且1999年以后随着城镇化的发展耕地主要转向建设用地.(3)近30年来鄱阳湖环湖区景观总体破碎程度逐渐增大,景观斑块个数共增加63492个,增幅为11.68%.景观连通性降低,各类型土地呈均衡化趋势分布,景观异质性增加.研究结果可为推动鄱阳湖环湖区土地资源保护、生态环境保护和经济协同发展提供参考依据.     

基于Landsat／TM和ETM＋的理塘草地沙化趋势及其驱动力分析

文章利用1989、1994、2000和2005年的4期Landsat／TM,ETM＋遥感影像,在几何校正、辐射定标、大气校正的基础上计算了归一化植被指数（NDVI）,建立最小二乘法线性回归方程对多时相NDVI进行同化处理,基于二分模型提取植被覆盖度并转换成荒漠化指数（DI）,对理塘县城附近约103．1km2范围的分类研究结果表明：（1）分为无沙化、轻度、中度、重度和严重沙化5级,其中2005年中度、重度和严重沙化面积分别为2．562km2、2．925km2和1．576km2;中度沙化比1989年减少9．69％,重度和严重沙化分别增多35．79％和161．8％;（2）2005年中度以上沙化面积比1989年增加1．470km2,增加了26．3％,年增加率为1．47％;（3）沙化面积呈前期小、中期大幅增加、后期增加减缓的总体趋势;（4）降水量和风速因子的变化趋势有利于缓解沙化,气温变化趋势没有反映出对沙化的促进作用。人类活动是造成沙化趋于恶化的主要因素;（5）沙化增加趋势与同类研究结果一致。     

丝瓜瓤固定化脱色菌Enterobactor sp.S8 对活性黑5的脱色

利用植物载体丝瓜瓤对肠杆菌(Enterobactor sp.S8)进行固定,并对活性黑5进行脱色研究.探讨了固定化菌体的菌龄、菌量、pH、温度对染料脱色的影响.研究了该固定化菌体的重复利用和动力学实验.结果表明,最佳脱色条件为:菌龄3d、接菌量2％、温度30℃、pH 6.0.该固定化菌体对不同初始浓度活性黑5的脱色符合二级反应动力学方程.经9次重复利用后的该固定化菌体,其脱色率仍达76.8％.在优化实验条件下,根据降解3d前后的紫外-可见光谱图分析可知,活性黑5并非完全被降解为CO2和H2O,而是生成一些小分子有机中间体.     

Assessment of Chlorophyll-a Concentration and Trophic State for Lake Chagan Using Landsat TM and Field Spectral Data

In this study, we present the digital evaluation of Landsat TM data and field spectral measurements for retrieving chlorophyll-a (chl-a) concentration and trophic state index in Lake Chagan of Northeast China. Chl-a concentration of the lake can be estimated from the band ratio (TM4/TM3) and the field spectral data at 670 nm (absorption peak) and at 700 nm (reflectance peak). The results show that the best determination coefficient (R ²) is 0.67 from the TM data, by which chl-a distribution can be mapped. Based on chl-a determination from laboratory analysis, field spectral and TM data, the modified trophic state index (TSI_M) was applied to assess the lake’s trophic state. With the available data in Lake Chagan, each algorithm demonstrates the similar result for assessing the lake’s chl-a and trophic state. Our results indicate that Landsat TM and field spectral data could be used effectively to determine chl-a concentration and evaluate the trophic state of Lake Chagan in the study.     

Oxidative damage in gill of Mytilus edulis from Merseyside, UK, and reversibility after depuration

Mussels were collected from the urban/industrialized site of New Brighton, Merseyside and the relatively non-industrial site of Llandudno, North Wales. All mussels were identified as Mytilus edulis by PCR amplification of Mefp1. DNA single strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine were measured in gill within 24h of collection, using the COMET assay, both with and without formamidopyrimidine glycosylase. Gill lipid peroxidation was also measured within 24h. No difference between sites was found for frank SSB and malonaldehyde levels, however 8-oxo-dG and 4-hydroxynonenal were significantly greater in New Brighton mussels compared to Llandudno mussels. After 1-month laboratory maintenance, lipid peroxidation and 8-oxo-dG levels were lower. In contrast, frank SSB were higher. This could reflect enhanced DNA repair excision, though we cannot exclude the possibility of other non-oxidative DNA damage. The results suggest that laboratory maintenance allows recovery from environmentally induced oxidative damage, which was more extensive at Merseyside.     

土地利用/覆被变化对小流域地表温度的影响

遥感和GIS技术被用于检测白家湾河流域土地利用/覆被变化,并评估土地利用/覆被变化对白家湾河流域地表温度的影响。不同时期的Landsat TM和ETM+影像被用于确定土地利用/覆被变化格局,并对矿点增长及相关的植被覆盖减少情况进行量化。采用Landsat数据的热红外波段进行地表温度的反演。结果表明:(1)小流域内不同土地利用/覆被类型上地表温度具有差异;(2)由于不同时期不同人为干扰造成的影响不同,不同时期土地利用/覆被类型间的地表温度差异不同。(3)在整个研究区域内,平均地表温度和NDVI之间呈负相关关系,各种土地利用/覆被类型上的平均地表温度和NDVI都呈现负相关性,但一些土地利用/覆被类型与NDVI的相关性高于平均水平。(4)植被覆盖情况越好,对稳定地表温度所起的作用越大。