胶州湾沉积物中石油降解菌的降解能力及多样性研究

2013年青岛输油管道爆炸,大量石油污染了附近海岸。课题组采集了污染的沉积物样品,以原油为唯一碳源和能源,富集了四个石油降解菌群。生物多样性和群落分析表明,Luteibacter、Parvibaculum 和属于食烷菌科的一个属是降解菌群的主要优势菌,都属于变形菌门。从石油降解菌群中分离筛选,获得了9株具有不同16S rRNA基因序列的降解菌,分别属于8个属。重量法测定降解菌的石油降解率,其中5株的石油降解率大于30%。GC-MS分析结果表明,石油降解菌多倾向于降解烷烃,对多环芳烃的降解能力较差,其中5株细菌的烷烃降解率较大,仅1株菌D2对多环芳烃的降解率较大,其降解率在34.9%到77.5%。通过对高通量数据的分析,表明食烷菌属是菌群A和菌群E的主要降解菌群,其中筛选获得的菌株E4可能是菌群E的一株优势降解菌。本研究所筛选菌株证明了其石油降解潜力,为油污染海滩生物修复提供了菌株资源。     

广州城市流浪乞讨者的空间管治与日常生活实践

以广州流浪乞讨者为研究对象,通过深度访谈等质性研究方法,解读针对流浪乞讨者的空间管治政策与手段,分析流浪乞讨者的日常生活实践与生境协商。研究发现：在地方城市政策对流动性与公共秩序限制的双重压力下,在流浪乞讨者的日常生活实践中,不仅有针对管治行动者而刻意为之的特殊营建,亦有基于程式化生活流程对自我身份认同的重塑与真情实感的展演。地方政府基于空间目标的救助与真实存在的日常生活实践存在着一种张力。研究关注了城市边缘群体日常生活对地理意义的主动塑造过程,对全面理解并规范管理中国城市流浪乞讨现象具有借鉴意义。     

相对剥夺视角下的乡村旅游地居民不规范行为研究 ——以江西婺源县李坑、思溪为例

居民不规范行为危害性极大,传统相关研究多基于社会交换视角,存在一定局限。相对剥夺理论在研究人们的不规范行为上存在一定优势,但鲜有应用于旅游研究。以社区问题明显的李坑、思溪两村落为例,结合相对剥夺理论对居民不规范行为的成因和形式等进行了定性分析。与传统研究不同,发现居民不规范行为与其对旅游负面影响的纵向感知并无直接关系,而主要与横向剥夺感相关。研究表明,相对剥夺理论或可作为居民旅游态度和行为研究的新视角,并在预防和管控旅游地社区问题方面具有重要现实意义。     

A method for the extraction of partition lines from long and narrow patches that account for structural features

The extraction of partition lines for long and narrow patches (LN patches) is an important yet difficult problem in the generalization of thematic data. When current methods are used to process polygons with irregular shapes or complex branch convergence zones, the extracted line structural features tend to be inaccurate and topologically erroneous. In this article, we propose an improved partition lines extraction algorithm of constrained Delaunay triangulation to counter these issues. The proposed method aims to maintain consistency between the extracted line structure characteristics and the actual object structure, especially for complex branch convergence zones. First, we describe three types of aggregation patterns (Type A, B, and C aggregation zones) that occur in partition line extractions for LN patches of complex branch convergence zones using Delaunay triangulation. Then, a partition line extraction algorithm that accounts for the direction between the edges of triangles and the distance of nodes in aggregation zones is proposed. Finally, we test our method for a dataset relating to Guizhou Province, China. Compared with the current method that uses quantitative indicators and visualization, the results indicate that our method not only has applicability for simple situations but also is superior for preserving structural features of complex branch convergence zones.     

基于资源三号卫星立体像对的DEM提取实验及其应用——以拉萨市城关区为例

利用测绘卫星立体像对提取DEM效率高、精度高。本实验的主要目的是进行资源三号测绘卫星立体像对高海拔地区DEM提取实验,比较正视、前视及后视3种视角全色影像不同组合情况的立体像对所提取DEM的效果,以拉萨市城关区为实验区,并将实验结果与SRTMDEM进行比较。实验结果显示,正视与前、后视组成的立体像对提取的DEM效果相当,均好于前视、后视全色影像组成的立体像对提取得到的DEM,拉萨市城关区空间分辨率可达10 m,效果良好,可为城市地质灾害评价等提供基础数据。     

海洋发光弧菌生长和发光条件的研究

海洋生物发光研究对渔业、环境监测等有着举足轻重的意义。根据从湛江东海岛海域沉积物样品中分离出的一株海洋发光弧菌(Vibrio sp.,编号为D2),对这株菌的生长和发光条件进行了初步研究。实验结果表明,海洋发光弧菌D2在pH7.0、温度35℃、NaCl浓度为2.0%时,生长状态最好;在pH5~6、温度20℃、NaCl浓度为3.0%、细菌密度OD600达0.08时,发光强度最高。     

Urban three-dimensional expansion and its driving forces —A case study of Shanghai, China

Urban expansion is a phenomenon of urban space increase, and an important measuring index of the process of urbanization. Taking Shanghai as an example, the changes of urban average height and built-up area were studied to represent city’s vertical and horizontal increases respectively, and statistical methods were used to analyze the driving forces of urban expansion. The research drew following conclusions: 1) The urban expansion process of Shanghai from 1985 to 2006 had a clear periodic feature, and could be divided into three stages: vertical expansion in dominance, coordinated vertical and horizontal expansion, and horizontal expansion in dominance. 2) The average height and quantity of buildings in core city were significantly bigger than those in suburbs, but the changing speed of the latter was faster. And 3) urbanization process was the major driving force for the city’s horizontal expansion, while industrial structure improvement was the key driving factor for the vertical expansion. Those two driving forces were simultaneously affected by city’s political factors.     

德州市临盘采油区地面沉降监测

济南市的鹊山上设立了3块岩层水准标石的原点组。使用美国Tri mble Di Ni 12电子水准仪和条码式铟钢水准标尺施测一等精密水准82.2 km,二等精密水准30.8 km,联测各类水准点35个。对观测结果进行统计与分析表明,在临盘采油区(以后仓西北采油四队LY18为中心)形成了一个较明显的沉降区域,年沉降量为54.3 mm。建议在其周边增埋地面观测标石,进行加密观测,以掌握其变化规律。     

Paleoenvironmental implications of the guano phosphatic cementation on Dongdao Island in the South China Sea

The phosphatic cement in the bioclastic sediment sequence on the northeastern shore of Dongdao Island in the South China Sea was studied and its paleoenvironmental implications discussed. Petrological characteristics and major, trace, REE element data unequivocally supported the notion that phosphatization was closely associated with avian guano decomposition and leaching, whereas carbon and oxygen isotope results further revealed that meteoric water were involved in these processes. AMS ¹⁴C dates on the brown phosphate cements indicate that they were formed around 5700, 5000–5100 and 2900 yr BP, respectively. The multi-episodes of phosphatization very likely correspond to intermittent seabird occupation on this island — possibly reflecting Holocene sea-level oscillation and/or long term climate changes in the South China Sea that have controlled seabird habitat. The phosphate cementation, which occurs widely in tropical islands, may be another useful monitor for sea-level and/or paleoclimate changes.     

Comparison of the effects of short-term UVB radiation exposure on phytoplankton photosynthesis in the temperate Changjiang and subtropical Zhujiang estuaries of China

We examined the effect of solar ultraviolet radiation B (UVB, 280–315 nm) on photosynthesis of natural phytoplankton assemblages in the temperate Changjiang River Estuary (CRE) in the East China Sea (ECS), and the subtropical Zhujiang River Estuary (ZRE) in the South China Sea (SCS) from August 2002 to April 2003. The short-term effect of UVB was assessed by exposing samples in quartz tubes/bottles to solar radiation under three treatments: (1) natural sunlight (NS) with UVB (NS-UVB); (2) photosynthetically active radiation (PAR, NS cut off UVB); and (3) NS with additional artificial UVB (NS + A-UVB). Solar UVB apparently inhibited phytoplankton photosynthesis rates. In the temperate CRE-ECS, solar UVB reduced surface phytoplankton photosynthesis by about 28% in August and February, while in the subtropical ZRE-SCS the inhibition was only 22% in September and October. In the CRE-ECS, phytoplankton in the stratified water column displayed stronger UVB inhibition when deeper water samples were exposed to surface UVB. Phytoplankton in the mixed water column did not show strong UVB inhibition, while light shift exposure of deeper phytoplankton in the same water column to surface light produced similar results, indicating that mixing moderates UVB effects. In the ZRE-SCS, surface phytoplankton showed greater photoinhibition in January (sunny). However, in April (cloudy), phytoplankton showed little UVB inhibition. Incubation for a short time without UVB showed a large increase in Chl a at two stations in the ZRE-SCS, but a large decrease at the other station in the presence of UVB. In contrast, in the CRE-ECS, a similar incubation experiment without UVB showed a decrease in Chl a, and small UVB inhibition of Chl a at two stations. Nutrient conditions might have played a role in the difference of UVB inhibition between the two regions as the ZRESCS had relatively high concentrations of all nutrients while PO₄ was only 0.21 μM at one of the CRE-ECS stations. The results suggest that phytoplankton in temperate waters would be more responsive to variation of UVB than ones in subtropical waters.