A spectral response approach for detecting dominant phytoplankton size class from satellite remote sensing

An important goal in ocean colour remote sensing is to accurately detect different phytoplank- ton groups with the potential uses including the validation of multi-phytoplankton carbon cycle models; synoptically monitoring the health of our oceans, and improving our understanding of the bio-geochemical interactions between phytoplankton and their environment. In this paper a new algorithm is developed for detecting three dominant phytoplankton size classes based on distinct differences in their optical signatures. The technique is validated against an independent cou- pled satellite reflectance and in situ pigment dataset and run on the 10-year NASA Sea viewing Wide Field of view Sensor (SeaWiFS) data series. Results indicate that on average 3.6% of the global oceanic surface layer is dominated by microplankton, 18.0% by nanoplankton and 78.4% by picoplankton. Results, however, are seen to vary depending on season and ocean basin.     

数据报告：烘干方法与烘干温度对布莱克海脊沉积物含水量和孔隙率数据的影响

1引言 船上现场对164航次991A、995A和996E孔获取的沉积物进行含水量和孔隙率的测量时,是使用105℃恒温进行烘干的。本项研究主要是为了确认105℃的恒温烘干过程是否造成了测量值的偏高。向干燥的烧杯中加入适量沉积物样品,置于105℃对流恒温烘箱中烘干24小时至36小时（Paull,Matsumoto,Wallace,等,1996）,在船上使用此方法烘干沉积物然后测量含水量,利用此含水量数据,再结合干样的质量和体积值,就可以求算出孔隙率（孔隙的体积／样品的总体积）值,许多其它项目的研究都应用了这些数据。     

Response of Microcystis aeruginosa FACHB-905 to different nutrient ratios and changes in phosphorus chemistry

Cyanobacterial blooms are a global problem, with their occurrence tightly tied to nutrient loading. We cultured Microcystis aeruginosa FACHB-905 in growth medium with either inorganic(orthophosphate) or organic(β-glycerophosphate or polyphosphate) phosphorus and at different N:P ratios with 50:1, 30:1, 16:1, 4:1 and 1:4, serving as the phosphorus source. Fluorescence parameters were measured to determine the response of cellular responses to nutrient stress. Scanning electron microscopy(SEM) and estimates of antioxidant activity were employed to examine potential mechanisms of physical change. The results demonstrate that inorganic phosphorus was more bioavailable to M. aeruginosa relative to organic phosphorus in culture. The highest cell concentration(2.21×10~6 cells/mL), chlorophyll-a(0.39 pg/cell) and phycocyanin(1.57 pg/cell) quotas and high levels of chlorophyll fluorescence parameters( rETR, E_k, α, φ_(PSⅡ) and F_v/F_m) were obtained when phosphorus was supplied as K_2 HPO_4 at a N:P ratio of 16–30. Organic sources of phosphorus(β-glycerophosphate and polyphosphate) were bioavailable to M. aeruginosa. In addition, too concentrated orthophosphate(N:P=1:4) resulted in the oxidative stress and lipid peroxidation of cell membrane(identified by the antioxidant system activity), and the photosynthetic activity declined consequently. This study has demonstrated the effects of different phosphorus chemistries and N:P ratios on the cyanobacterial growth, photosynthetic activity and cell physiology, which could be an effective tool for predicting cyanobacterial dominance or N-deficiency in natural lakes(due to the superior ability of cyanobacteria for dissolved N and fix atmospheric N in some cases).     

大厂锡矿床成因综合分析及成矿模式

本文通过对大厂锡多金属矿床区域成矿地质环境、矿体形态特征、原生金属-矿物分带、矿床地球化学的综合分析与研究,论述了该矿床在许多方面具有喷气沉积成因的特点。为此,我们把大厂锡多金属矿床与块状硫化物矿床、绿岩带金矿床及某些层控锡矿床进行了对比,从而明确了大厂锡矿属于含锡块状硫化物型层控锡矿床。本文还从发展、演化的角度,对大厂层控锡矿形成后的变形-变质作用进行了系统研究,阐明了同生与后生地质现象同时存在的原因,解决了对该矿床所提出彼此矛盾成因假说的难题。最后,建立了大厂锡矿的成因模式,并探讨了该超大型锡矿形成的特殊地质环境。     

Carbon dioxide partial pressure and carbon fluxes of air-water interface in Taihu Lake, China

1 INTRODUCTION Carbon dioxide (CO2) is principal greenhouse gas. Its air-water exchange is important in terrestrial ecosystems for climate change (Frankignoulle et al., 1998; Schimel et al., 2001). The direction of CO2 gas movement depends on the CO2 concentration gradient between air and surface water. The amount of CO2 exchange is related to the gas exchange coefficient, k. All lakes, with their small area but large atmospheric CO2 flux are important to under-stand the CO2 fluxes …     

对流层高、低空急流的耦合和强对流风暴发展的关系

一、引言对流层高、低空急流的相互作用对于对流性风暴系统的发展很重要,这个概念是由福布什和米勒(Fawbush和Miller;1953,1954)提出来的。他们指出:伴随对流层中空强西风的冷、干平流和低空暖、湿舌迅速北伸,是深厚对流发展的有利条件。并且指出风向强烈顺转很可能增强对流,这样对流层中空的风向与低空湿舌轴线之间的夹角很大。彼得森(Petterssen,1956)和牛顿(Newton,1967)指出风随高度的顺转及其造成的高、低空急流轴线交叉点上温度和湿度差动平流与对流不稳定发展的关系。最大的对流不稳定发生在高、低空急流轴线趋于正交和平流强度最大的时候。关于对流层急流在强对流风暴发展中的作用,     

北京冬春季节大气气溶胶化学成份的研究

1980年3月6日至20日,利用美国佛罗里达州立大学自制的条式连续采样仪,在北京北郊大气物理所气象塔观测场取得连续两周的大气气溶胶样品。用PIXE方法分析,得到了该样品中 Ca、Fe、Al、Si、K、Cl、S、Ti、Mn、Zn、Sr、pb等微量元素的相对浓度。 本文分析了北京冬春季节大气气溶胶化学元素的浓度分布特征以及浓度变化与气象条件的关系。并与其他地区的观测结果作了比较。     

南半球气流的气候特征

依据几十年的船舶和陆基观测资料而得到的网格点上的平均地面地转风,来估算南半球月平均地面流线。在南半球已确认有4个年气流源地。在南半球冬季的7个月期间,澳大利亚是第5个气流源地区域。北半球的气流流到南半球(夏季)的热带辐合带处。在平均年份中,南半球空气来自上述4个年气流源地的占46％,太平洋贡献最大(20％),其次是印度洋(12％)、大西洋(9％)和南极洲(5％)。最常见的汇流带有4条。     

夏季110°E附近的低空越赤道气流与西北太平洋台风活动

在西北太平洋赤道地区夏季有一支源自南半球的气流.这支位于110°E 附近的大尺度季风气流是过去研究中所提到的源自澳洲的越赤道气流与中国低空急流.低空越赤道气流的强度变化与台风的发生发展有联系.     

Perfluorinated compounds in estuarine and coastal areas of north Bohai Sea, China

Perfluorinated compounds (PFCs) in water, sediment, soil, and biota collected from estuarine and coastal areas of the north Bohai Sea, China, were determined by use of HPLC-MS/MS. Significant concentrations of PFCs were found in water (mean: 18.4 ng/l) and biologic samples (fish: 265 ng/g dw), while concentrations of PFCs in soils and sediments were less. The predominately detected compound was perfluorooctanesulfonate (PFOS), with a maximum concentration of 30.9 ng/l in water and 791 ng/g dw in fish. Concentrations of PFCs were significantly greater in the Liaohe River system than other locations, which suggests point sources in this urbanized and industrialized region. PFOS concentrations in water and biota were both less than the reported threshold concentrations. Detection of PFCs at relatively great concentrations in various environmental matrices from this region suggested that further studies characterizing concentrations of PFCs, their sources and potential risk to both humans and wildlife are needed.