九龙江河-海系统夏季浮游植物磷胁迫研究

采用群落水平和细胞水平碱性磷酸酶活性(APA)相结合的方法,研究了2010年夏季(6-7月)九龙江河-海系统(河流-河口-邻近海域)浮游植物的磷胁迫,结果表明,单位叶绿素a的APA在河流下游区[(48.80±14.69)nmol/(h.μg Chl a)]显著高于河口区[(10.60±15.58)nmol/(h·μg Chl.a)]和邻近海域[(23.54±25.41)nmol/(h·μg Chl.a)],表明河流区的浮游植物磷胁迫显著高于河口区和邻近海域.三个区域高比例的游离态APA表明该水域浮游植物已较长时间处于磷胁迫状态.细胞水平的浮游植物荧光标记结果显示,河口区(20％±20％)与邻近海域(38％±20％)无显著差异(P＞0.05),此结果与群落水平APA结果相一致;但河口-邻近海域浮游植物的标记比例显著高于河流下游区(9％±3％)(P＜0.05).     

Urbanised beaches of the Ligurian coastal area (NW Mediterranean): A classification based on organic-matter characteristics and hydrolytic enzymatic activities

The beaches of Liguria have been intensively affected by human activities for over a century, transforming nearly the entire coastline from natural to urbanised and significantly upsetting beach ecological properties. The present study aims to investigate 9 Ligurian beaches characterised by different degree of urbanisation, to test if and to what extent the organic-matter (OM) recycling processes can be linked to the human activity. Swash zone sediment, sampled during the spring–summer–autumn period, when the anthropogenic influence is at its maximum due to tourism, was analysed for OM features and recycling processes. Multivariate statistical analyses showed that huge amounts of detrital OM accumulated in the more urbanised sites, where the anthropogenic influence was at its peak, deriving from higher inhabitant number and density, from the presence of crowded roads very near to the swash zone and sewage treatment plants. The presence of torrent outlets on the beaches provided further OM accumulation. Lipids, carbohydrates and degraded autotrophic pigments were the OM fractions mainly responsible of the differentiation, and rather constant, high labile phosphorus contents were found in the more urbanised sites. The high activity values of the hydrolytic enzymes indicate the response of the microbial system to the OM accumulation in the urban sites. However, a decoupling of the trends of some enzymatic activities (namely glucosidase and lipase) and their target OM was observed in the highly urbanised conditions.     

Weed preference and growth of young grass carp in New Zealand

In each of eight 5‐day pond experiments carried out at intervals over a year, 0+ to 1 +‐year‐old grass carp, Ctenopharyngodon idella Val., were offered a choice of at least 10 species of water weeds from the Rotorua area. Water temperature was measured each day. Food selectivity decreased with increasing temperature and size of fish, but preference for the weeds did not change. At summer temperatures the fish ate much weed and grew at about 4g/fish/day, but in winter little food was taken and growth was slow.     

Population dynamics and chemical ecology of New Zealand Demospongiae Latrunculia sp. nov. and Polymastia croceus (Poecilosclerida: Latrunculiidae: Polymastiidae)

For 3 years aspects of the population dynamics, growth, and bioactivity (measure of biologically active metabolite biosynthesis) of the Demospongiae Latrunculia sp. nov. and Polymastia croceus (Kelly‐Borges & Bergquist) were examined on a subtidal reef on the Wellington south coast, New Zealand. For both species, survival of adult sponges was high in all seasons, whereas juvenile sponges had poor survival. Recruitment of Latrunculia sp. nov. occurred in all seasons indicating that this species is reproductively active throughout the year. P. croceus recruited mostly in autumn, supporting previous work that found the sponge to be reproductively active in summer and early autumn only. For both sponge species, growth rates varied greatly between individuals and were unaffected by initial sponge size within the range examined. Sponges generally grew during winter and spring as the water temperature rose, and shrank during summer and autumn as the water temperature fell. This growth pattern may relate to seasonal variation in food abundance, and for P. croceus it may result also from seasonal differences in reproductive investment. After 2 years, Latrunculia sp. nov. and P. croceus had on average, halved and doubled in size, respectively. Latrunculia sp. nov. showed a seasonal pattern of bioactivity, being most active in spring possibly to prevent the surface overgrowth of fouling organisms. P. croceus had no seasonal pattern of bioactivity, but individuals were either very active or inactive. The bioactive metabolites in both species possibly aid in competitive interactions and prevent predation and biofouling.     

溶藻细菌MS7的分类鉴定及其溶藻活性的初步研究

采用形态学、生理生化指标和16SrRNA基因序列同源性分析的方法,对菌株MS7进行鉴定,并通过溶藻试验测定该菌株对铜绿微囊藻(Microcystis aeruginosa)的溶藻活性和溶藻方式。结果表明,MS7菌株为苏云金芽孢杆菌(Bacillus thuringiensis),对铜绿微囊藻具有高效溶藻效果,当菌浓度为108cells/mL,初始藻液叶绿素a浓度为0.7mg/L时,48h溶藻率达到91%。主要通过分泌胞外物质的间接方式溶藻,溶藻物质属于具有很强的热稳定性的非蛋白质类物质。     

Solar cycles during the Maunder minimum

We have obtained new consistent versions of the 400-yr time series of the Wolf sunspot number W, the sunspot group number G, and the total sunspot area S (or the total sunspot magnetic flux Φ). We show that the 11-yr cycle did not cease during the Maunder minimum of solar activity. The characteristics of the extrema of individual 11-yr cycles in 1600–2005 have been determined in terms of the total sunspot area index. We provide arguments for using alternating (“magnetic”) time series of indices in investigating the solar cyclicity.     

Extrinsic and intrinsic forcing of fluvial development: understanding natural and anthropogenic influences

This paper introduces a special issue arising from the biennial meeting of the Fluvial Archives Group (FLAG) that took place in September 2008 in Budapest, Hungary. Combining a two-day conference and three-day field excursion, this meeting provided an excellent opportunity for presentation and discussion of recent advances in research on fluvial evolution from the Plio-Pleistocene to the historical period. This editorial seeks to place these advances within the contexts both of long-term geomorphological research and the achievements of FLAG. It thus highlights progress towards a better understanding of fluvial responses to internal and external (including anthropogenic) forcing. It also points out some of the main obstacles, which can be targeted as goals for further research. Typically these relate to observed discrepancies in fluvial system responses, such as in patterns of lateral erosion and the timing of terrace incision, despite apparently similar fluvial parameters. Possible explanations for these discrepancies are mentioned, and the potential of new methods (especially in geochronology and modelling) to clarify such discrepancies is underlined. Finally the editorial provides brief reviews of the ten papers in this special issue (many of them developed from presentations in Budapest), which cover various areas in Europe (Hungary, England, Germany, Portugal, Russia), Asia (India) and South America (Bolivian Andes), placing them, in turn, within the context of this wider review of fluvial research.     

大南盘江地区构造对油气藏破坏作用研究

大南盘江地区发育多套成熟烃源岩,具有良好的油气成藏条件。但由于烃源岩埋藏深、成熟早,成藏之后经历多期强烈的后期构造运动改造,先前形成的油气藏大都被破坏,导致目前地表出露多处古油藏和油气苗。多年的油气勘探证实,后期的构造运动对油气藏的破坏作用是制约该区油气勘探的关键问题。研究表明,大南盘江地区不同构造单元,油气藏的破坏因素不同。南盘江坳陷古油藏沿深大断裂分布,其破坏的主控因素是断裂活动;桂中坳陷古油藏和油气显示出露区缺失区域盖层,其破坏的主控因素是构造抬升剥蚀;十万大山盆地古油藏目前残留的烃类主要是固体沥青,镜质体反射率(Rb)大都落在2.0以上,推算经历的最高热解温度均大于200℃,而且古油藏的分布区也是印支期岩浆岩集中分布区,因此推断该区油气藏破坏的主控因素是岩浆活动。     

改进灰色马尔科夫模型及其在水资源预测中的利用

这里首先对灰色系统理论GM(1,1)模型的算法进行改进,并将改进后的灰色模型与马尔科夫模型结合。通过对灰色系统预测数据的修正,既发挥了灰色系统预测精确的特点,又利用了马尔科夫模型对预测波动性数据准确的优势,对于在任何时间序列上展开的具有一定波动性的数据进行预测,精度更高。     

中原油田高压注水诱发的油水井套管损坏原因分析

中原油田高压注水开发35年,套管损坏严重,严重的影响了油田的开发效果。据研究,油田水井套管损坏主要有错断、变形及破漏等三类,平面上主要分布在断层发育区、高地层水矿化度区、泥岩层和盐膏层发育区,剖面上主要分布在盐膏层段和主力生产井段。提出断层活动、地应力非均质演化、盐岩蠕变、油田开发历程和开采方式及油气流场、化学场演化是中原油田套损的主要控制因素,建立油田油藏油井多参数动态模式,优选与油藏模式匹配的开采方式及增产措施,改造套管动力学环境和化学环境将能防治套损地质灾害的发生。