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871.
针对南极普里兹湾内达恩利角附近海域的3个测站共12份海水样品,采用寡营养培养基分离培养极地浮游细菌,通过PCR方法获取其中95株细菌的16S rRNA基因序列。序列分析结果表明,分离获得的95株细菌分属α-变形杆菌纲(Alphaproteobactia)、γ-变形杆菌纲(Gammaproteobacteria)和拟杆菌门(Bacteroidetes)3个类群下的35个不同分类单元,其中α-变形杆菌纲为优势细菌,在不同水层中所占的比例为52.6%—62.5%。通过Shannon多样性指数分析发现,南极普里兹湾陆架区测站P2-14多样性指数较陆坡区两测站P2-11和P2-8的高,细菌多样性与浮游植物量和生产力水平呈现正相关。表层细菌Shannon多样性指数最低,50 m水层最高,100和200 m水层多样性指数变化不明显,真光层水体中细菌垂直分布与营养盐和溶解氧浓度存在关联。此外,采用寡营养陈海水培养基,还获得了一些与已报道的16S rRNA基因序列相似性较低的菌株,它们代表了微生物新物种,可能也是南极真光层特有的细菌。研究工作表明,南极普里兹湾真光层水体中蕴藏着丰富的浮游细菌资源,它们有待保护、开发和利用。 相似文献
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874.
In order to clarify the statistical pattern by which landfalling strong tropical cyclones(LSTCs)influenced the catastrophic migrations of rice brown planthopper(BPH),Nilaparvata lugens(stl)in China,the data of the LSTCs in China and the lighting catches of BPH that covered the main Chinese rice-growing regions from 1979 to 2008 were collected and analyzed in this work with the assistance of ArcGIS9.3,a software of geographic information system.The results were as follows:(1)In China,there were 220 strong tropical cyclones that passed the main rice-growing regions and 466 great events of BPH’s immigration in the 30 years from 1979 to 2008.73 of them resulted in the occurrence of BPH’s catastrphic migration(CM)events directly and 147 of them produced indirect effect on the migrations.(2)The number of the LSTCs was variable in different years during 1979 to 2008 and their influence was not the same in the BPH’s northward and southward migrations in the years.In the 30 years,the LSTCs brought more obvious influence on the migrations in 1980,1981,2005,2006 and 2007.The influence was the most obvious in2007 and all of the 7 LSTCs produced remarkable impact on the CMs of BPH’s populations.The effect of the LSTCs on the northward immigration of BPH’s populations was the most serious in 2006 and the influence on the southward immigration was the most remarkable in 2005.(3)In these years,the most of LSTCs occurred in July,August and September and great events of BPH's immigration occurred most frequently in the same months.The LSTCs played a more important role on the CM of BPH’s populations in the three months than in other months.(4)The analysis on the spatial distribution of the LSTCs and BPH’s immigration events for the different provinces showed that the BPH’s migrations in the main rice-growing regions of the Southeastern China were influenced by the LSTCs and the impact was different with the change of their spatial probability distribution during their passages.The most serious influence of the LSTCs on the BPH’s migrations occurred in Guangdong and Fujian provinces.(5)The statistical results indicated that a suitable insect source is an indispensable condition of the CMs of BPH when a LSTC influenced a rice-growing region. 相似文献
875.
基于中国南海海域风暴环境条件,研究分析南海海域固定式导管架平台结构整体性和可靠性,以及新建固定式平台结构设计准则。采用海洋环境数据后报方法,得到南海海域1972~2011共40年的风、浪、流联合数据,从中抽取风暴环境条件;利用通用荷载模型,将40年间的风暴环境数据转变成结构的荷载数据,即基底剪力或倾覆力矩;并计算得到风暴环境荷载的短期及长期分布,以及任意风暴下荷载的概率分布;根据结构可靠性模型,结合荷载的长期分布,研究基于结构暴露等级及失效概率的固定式平台结构强度储备比。根据计算,得到了不同暴露等级下中国南海平台的强度储备比,并与墨西哥湾及北海海域进行了比较,为新建平台提供设计参考。 相似文献
876.
通过对三山岛岸段冬夏重复的地形测量和表层沉积物的粒度分析,研究了其地貌特征与地形变化规律、沉积物类型、粒度特征、运移趋势,并探讨了沉积物运移的动力机制。结果表明:该岸段可根据1985黄海高程-1.2m(低潮水位)和-6.5m(闭合深度)平面划分为海滩、水下岸坡和浅海陆架三个地貌单元,各地貌单元表层沉积物分布规律与地形变化特征区别显著。其中水下岸坡和浅海陆架地貌单元主要受潮流作用,海滩地貌单元主要受波浪作用。在西向落潮流和西南向潮余流的作用下,水下岸坡地貌单元发育一个中等规模潮流通道-沙脊沉积系统。表层沉积物以向西运移的趋势为主,少数滞留于西部潮流沙脊处,与地形"东侵西淤"的变化规律相符,这些西向运移的沉积物最终离开研究区,补给莱州浅滩。 相似文献
877.
采用溶液插层法,利用壳聚糖和蒙脱土制备了壳聚糖/蒙脱土插层复合物,使用红外光谱和X-射线衍射分析对其结构进行了表征;以此复合物为活性红染料RR136的吸附剂,考察了复合物中壳聚糖与蒙脱土的摩尔比、染料溶液pH值和浓度、吸附温度及吸附剂用量等因素对吸附性能的影响。结果表明,吸附反应的最佳条件是以壳聚糖与蒙脱土摩尔比为5∶1的插层复合物为吸附剂,反应温度20℃,RR136溶液pH为3。壳聚糖/蒙脱土插层复合物对活性红染料的吸附更符合Langmuir模型,吸附热力学参数ΔGo、ΔHo和ΔSo值分别为-3.338kJ·mol-1(30℃),-37.98kJ·mol-1和-114.77J·mol-1·K-1,表明壳聚糖/蒙脱土插层复合物对活性红染料的吸附是自发的、以物理吸附为主的放热反应。 相似文献
878.
Won Duk Yoon Hye Eun Lee Changhoon Han Soo-Jung Chang Kyunghoon Lee 《Ocean Science Journal》2014,49(3):183-192
Nemopilema nomurai have appeared massively since 2003 in Korean waters, and regular offshore monitoring has been performed since 2005 in the eastern Yellow Sea (YS), northwestern East China Sea (ECS), Korean southern waters (Ksw), and western East Sea (ES). Korea Jellyfish Monitoring Network (KoJEM) was established in 2006 for coastal jellyfish monitoring. From these, sight survey monitoring data were gathered and analyzed to extract the yearly and seasonal fluctuation of N. nomurai’s abundance and distribution. The first massive annual appearance of N. nomurai occurred in the northwestern ECS, off Shanghai, China, in mid May of 2005–2008 and of 2012–2013. In other years or concurrently with the appearance in the northwestern ECS in the same year, several individuals were found in the mid-eastern YS and Ksw, and southwestern ES. The population of N. nomurai at the northwestern ECS moved to the southeastern YS and Jeju Strait in June, and from the July to August it extended its distribution all around the Korean peninsula and persisted till October. Since October, the distribution was retracted into the southern YS and Ksw, and disappeared slowly. N. nomurai’s yearly abundance varied a lot, from nearly 0 inds 10?4m?2 in 2010 to 62.4 inds 10?4m?2 in 2005. The highest abundance was recorded in 2005, followed by 2007 and 2009, and the least abundance was in 2008 and 2010–2013. The results were compared with those of the Liaoning Bay, Bohai Sea, which led to speculation about a new seeding place of N. nomurai, and mortality during the early planktonic phase of N. nomurai was proposed as the determinant of the yearly variation in abundance. 相似文献
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880.
?????????????????????????ο??????????????????????????????????????????????????????????NGA?????????????????????????飬??????????????????????о?????????????????????????????????????????2012?????4.7??????????е?????????????????????????????????????PGA??????S??a??T???????б????о?????????????????????????????????????????????????????????????????????????????????????????????? 相似文献