Mortality of sea lions along the central California coast linked to a toxic diatom bloom

Over 400 California sea lions (Zalophus californianus) died and many others displayed signs of neurological dysfunction along the central California coast during May and June 1998. A bloom of Pseudo-nitzschia australis (diatom) was observed in the Monterey Bay region during the same period. This bloom was associated with production of domoic acid (DA), a neurotoxin that was also detected in planktivorous fish, including the northern anchovy (Engraulis mordax), and in sea lion body fluids. These and other concurrent observations demonstrate the trophic transfer of DA resulting in marine mammal mortality. In contrast to fish, blue mussels (Mytilus edulus) collected during the DA outbreak contained no DA or only trace amounts. Such findings reveal that monitoring of mussel toxicity alone does not necessarily provide adequate warning of DA entering the food web at levels sufficient to harm marine wildlife and perhaps humans.     

Influence of the Indonesian Throughflow on the upwelling off the east coast of South Java

A wave-tide-circulation coupled model is used to simulate upwelling off the south coast of Java, Indone- sia. The results show that the vertical velocity off East Java is stronger than other parts in this area. The strongest vertical velocity is located approximately at 80 m depth. The annual averaged values of upwelling are 2.3 × 10-6 and 1.06 × 10-5 m/s for south of West Java and south of East Java, respectively. The vertical velocity from the model shows that upwelling off West Java has seasonal variability, while it is quite steady and strong off East Java. Additional numerical experiments show that the wind is not the dominant factor for the steady upwelling off the southern part of East Java. It is then hypothesized that the Indonesian Throughflow （ITF） may be responsible for the upwelling. To test this hypothesis, two scenarios are implemented, both of which block the outflow of the ITF. Sensitive study shows that the ITF plays a key role in the formation of East Java upwelling. The effect of the ITF can account for about 55 %-65 % of the upwelling.     

Importance of stirring in the development of an iron-fertilized phytoplankton bloom

The growth of populations is known to be influenced by dispersal, which has often been described as purely diffusive. In the open ocean, however, the tendrils and filaments of phytoplankton populations provide evidence for dispersal by stirring. Despite the apparent importance of horizontal stirring for plankton ecology, this process remains poorly characterized. Here we investigate the development of a discrete phytoplankton bloom, which was initiated by the iron fertilization of a patch of water (7 km in diameter) in the Southern Ocean. Satellite images show a striking, 150-km-long bloom near the experimental site, six weeks after the initial fertilization. We argue that the ribbon-like bloom was produced from the fertilized patch through stirring, growth and diffusion, and we derive an estimate of the stirring rate. In this case, stirring acts as an important control on bloom development, mixing phytoplankton and iron out of the patch, but also entraining silicate. This may have prevented the onset of silicate limitation, and so allowed the bloom to continue for as long as there was sufficient iron. Stirring in the ocean is likely to be variable, so blooms that are initially similar may develop very differently.     

A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization

Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.     

SHADE协调机制在亚丁湾、索马里海域护航中的作用

信息共享与防止冲突(简称SHADE)这一军事协调会议为国际社会开展多边合作实施海上护航提供了平台。通过梳理SHADE协调机制产生的背景及运作方式,并以第14次工作会议为例,分析了SHADE这一国际协调机制在打击索马里海盗、维护海上航行安全中的作用,同时指出了其存在的不足。     

A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean

The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.     

The biogeochemical behavior of dissolved aluminum in the southern Yellow Sea: Influence of the spring phytoplankton bloom

Many recent studies have investigated the nutrient-type profiles of dissolved aluminum(Al) in the ocean.Significant scavenging of dissolved Al can occur during phytoplankton blooms,but the mechanism remains unclear.The distribution of dissolved Al in the southern Yellow Sea(SYS) was investigated in winter and spring 2009.Following measurements at grid stations during the spring sampling cruise,two drifting anchor surveys of more than 100 h were conducted to trace the variation of dissolved Al concentration during the spring phytoplankton bloom(SPB).The concentration of dissolved Al in the SYS decreased from 40 nmol/L in February to 30 nmol/L in March and 10-20 nmol/L in April,while the concentration of Chl a increased from < 2 μg/L in March to > 4 μg/L in April.The concentration of dissolved Al in the SYS decreased significantly with the development of the phytoplankton bloom,which indicated biological scavenging of dissolved Al from water column.The proportion of dissolved Al scavenged from water column by different phytoplankton species differed at the two drifting stations,with greater removal efficiency demonstrated by diatoms than dinoflagellates.Phytoplankton samples collected from the Chl a maximum layer were washed with trace metal clean reagent(oxalate-EDTA-citrate,abbreviate as oxalate solution,Tovar-Sanchez et al.,2003) to enable the surface-scavenged(extracellular) and intracellular Al pools associated with phytoplankton to be differentiated.Thirty-nine to ninetysix percent of the total Al was found to be existed in the interior pools,which indicated that biological absorption was the important way to scavenge dissolved Al during phytoplankton blooms in the SYS.     

江苏沿海2016年夏季冷水块的特征分析

利用走航CTD观测资料和AVHRR资料分析了江苏沿海2016年夏季(6—8月)冷水块特征.7月18—21日的走航CTD观测资料表明,从海面到30 m层都存在冷中心,冷中心逐层向东倾斜,显示存在从黄海沿底部向江苏沿海输送冷水的通道.AVHRR资料的月平均海表温均存在冷水块,其半径为67.9~85.8 km,强度为0.5~1.2℃,冷水块中心与沿岸温差为1.9~2.9℃;逐日的海表温有78 d存在冷水块,最大半径161.8 km,最大强度2.8℃,与沿岸最大温差为5.9℃,其中心位置变化大,相邻两天中心位置的最大距离为125.4 km.逐日冷水块和风场对比分析表明,南风有利于冷水块的生成.     

Interpreting grain-size trends associated with bedload transport on the intertidal flats at Dafeng, central Jiangsu coast

IN THE MARINE ENVIRONMENT, IT IS OFTEN DIFFICULT TO IDENTIFY THE NET SEDIMENT TRANSPORT PATHWAY BECAUSE OF THE COMPLICATED HYDRODYNAMICS AND SEDIMENT SOURCES. GAO AND COLLINS HAVE RE-EXAMINED A 1-D MODEL ORIGI- NALLY DERIVED BY MCLAREN AND BOWLES AND DEVE…     

辽东半岛东岸潮间带沉积物重金属含量分析及污染评价

重金属是近岸海域常见污染物之一,以辽东半岛东岸碧流河口潮间带海域为研究区域,使用WSS重力沉积物采样器,钻取2根柱状样,对该海域沉积物中的7种重金属元素Cu、Pb、Zn、Cr、Ni、Mn、Co的含量、污染程度及潜在生态风险进行检测和分析评价.结果表明:7种重金属元素含量的平均值分别为33.86 mg/kg、79.24 ...     

Digitization characteristics of geothermal information and structural analysis of 2011 off the Pacific coast of Tohoku Ms9.0 earthquake

Earthquake is one of the difficult problems that can not be solved as of this writing since the time when modern science was initiated over 300 years ago, and irregular events cannot be dealt with by using quantities examples before and followed by a view of the number of analysis systems in modern science; meanwhile, it covers the problem that how to use changeable information. Structural analysis method is developed particularly for the study of evolutionary transitional processes of the changing events by employing irregular information, and emphasizes the primitiveness of changes in events. Based on the data of sounding observation every 08 o’clock and 20 o’clock per day from China Meteorological Administration, in this paper, we employ the digital structural analysis method to analyze the process of the special, structural characteristics of 2011 off the Pacific coast of Tohoku Ms9.0 earthquake. The result shows that the method can reflect the process of geothermal structures before and after earthquake; it can reflect the congruity between geothermal heat level and the level of earthquake energy. When the structure before the earthquake is the counter clockwise rolling current and the unstable structures with dry in lower levels and wet in upper levels, we should be worry about the problem of earthquake. In a word, geothermal information could reveal that earthquakes really would be heralded.     

2022年汤加火山喷发与海啸观测

2022年1月15日世界标准时间4∶14,位于南太平洋汤加俯冲带火山链区域的Hunga Tonga-Hunga Ha’apai(HTHH,175.39°W,20.55°S)火山爆发并激发全球性海啸。聚焦火山喷发和海啸波的观测方法,介绍了海底传感器、大气波变化卫星图、电离层扰动对火山喷发和海啸的最新监测结果。结合该区域的地质构造与火山喷发历史资料,综述了2022年汤加HTHH火山喷发引起的海啸特征、最新观测手段,提出了对俯冲带火山海啸等进行详细的海洋地球物理调查、基于观测综合量化研究海底火山大规模喷发对全球气候的潜在影响等建议。     

Satellite SAR interferometric observations of displacements associated with urban subsidence in Suzhou, Eastern China

SAR interferometry (InSAR) has a high potential for surface displacement mapping in the range from millimeter to meter. In this paper the potential of ERS-1/2 SAR interferometry for mapping subtle land subsidence has been investigated. A time series of ERS-1/2 SAR data from February 1993 to February 2000 is collected from measurements taken in Suzhou city, Jiangsu Province, China, eight ERS-1/2 SAR images are used to create seven interferograms, and three differential interferograms are produced using the three-pass method, which clearly show the spatial extent of land subsidence. The deformation maps are validated by leveling surveys, the correlation coefficient and standard deviation between them are 0.943 and 0.1706 respectively. Based on seven benchmarks, the subsidence rates are estimated, the overall trends are in close agreement with InSAR results. The results of study show that for the mapping of land subsidence in urban environments InSAR has a strong potential due to its cost-saving, high resolution and accuracy.     

城市化进程中失地农民权益流失与保障

农村的城市化进程产生了大量的失地农民，他们的权益受到侵犯，形成了一个特殊的弱势群体，随时都可能引发新的社会矛盾和冲突。妥善安置失地农民，维护其合法权益，是我国社会发展中必须面对而又急需解决的问题。本文从完善政策保障机制、社会保险机制、就业保障机制、农地创新机制四个方面对失地农民权益保障的途径和方法进行了探讨。     

普通数码相机生物显微摄影技巧

结合数码相机与普通光学显微镜在拍摄相片过程中的正确调节，充分发挥数码相机的性能优势，拍摄出超越传统相机拍摄效果、令人满意的数码显微照片。     

具有生物活性的山梗碱类生物碱的合成研究

山梗碱类生物碱多为2,6位上各有一侧链的哌啶类化合物。本文报道了山梗酮碱(Ⅱ)、去甲山梗酮碱(Ⅲ)、山梗醇碱(Ⅳ)、去甲山梗醇碱(Ⅴ)、2,6-二丙酮基哌啶(Ⅵ),N-甲基-2,6-二丙酮基哌啶(Ⅶ)及2-丙酮基-6-苯甲酰甲基哌啶(Ⅷ)的合成。以苯基锂为催化剂使2-甲基-6-丙酰甲基吡啶的缩酮(Ⅺ)与苯甲醛反应时,缩酮被破坏而得到2-甲基-6-(2,2-二苯基丁基)吡啶(ⅩⅥ)。以氨基钠作为催化剂时,苯甲醛转变为苯甲酰胺。Ⅳ和Ⅴ对呼吸中枢有较强的兴奋作用。     

细粒焦渣对废水中酚的吸附研究

利用焦化厂细粒焦渣对苯酚的吸附 ,研究了各种因素 (焦粒大小、pH值和溶液的滤速等 )对吸附的影响 结果表明 ,在 2 5℃ ,滤速为 4 .5mL/min ,pH为 2～ 2 .5,浓度为 30mg/L的苯酚溶液中 ,酚的去除率可达 98% 探讨了细粒焦渣对焦化厂含酚废水处理的可行性 图 4 ,参 10     

用FDTD法计算外开槽同轴波导的归-化截止频率

给出圆柱坐标系下用FDTD法计算电磁场问题的差分格式和用FDTD法分析开槽金属波导截止频率的主要计算过程。实例计算了具有解析的空心金属圆波导和同轴传输线的传输特性,证明了圆柱坐标系下FDTD方法的正确性和有效性;用同一程序计算无解析的开槽同轴波导的传输特性,分析了各种开槽条件下开槽同轴波导截止频率的影响。     

广西北部湾海岸带红树林变化的遥感监测

广西北部湾沿海是中国重要的红树林分布区,掌握广西北部湾红树林的动态变化趋势对红树林生态系统的保护与利用具有重要意义。为了定量分析广西北部湾红树林的变化情况,选取了美国Landsat卫星数据,以广西山口红树林自然保护区作为研究区域,收集了1978年至2014年间的遥感影像,结合实地调查以及各项资源调查数据的整理和分析,解译并统计了广西山口红树林保护区的红树林面积变化。结果表明:从1978年至1989年,广西山口红树林面积急剧减少;1989年至2014年,广西山口红树林面积逐渐恢复。