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81.
Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.8...  相似文献   
82.
1999年和2009年夏季珠江口环境要素的对比与分析   总被引:1,自引:0,他引:1  
对1999年和2009年夏季珠江口的温、盐、溶解氧、叶绿素和径流量等数据进行分析。结果表明,由于1999年航次期间珠江较大的径流量,1999年冲淡水的扩展范围要大于2009年。1999年夏季珠江口水体存在较强的盐度层结,而2009年夏季受较小的珠江径流量和热带风暴浪卡的共同作用,水体盐度层结较弱,0—5m层水体垂向混合良好。两年夏季珠江口表层溶解氧(DO)的分布较为相似,而底层溶解氧的分布则有显著差异,主要表现在河口西岸浅滩区和河口口门外。1999年河口西岸浅滩区DO小于3mg.L-1,河口口门外DO在4—5mg.L-1之间,2009年河口西岸浅滩DO大于5mg.L-1,河口口门外DO小于3mg.L-1。1999年夏季伶仃洋海域内较强的盐度层结是其底层出现低氧环境的主要原因,2009年夏季强化的垂向混合使得表底层溶解氧得到了及时交换,阻碍了西岸浅滩区底层低氧环境的出现,而盐度层化和浪卡带来的浮游生物的耗氧作用可能是口门外底层出现低氧环境的原因。  相似文献   
83.
利用设立于厦门岛西南部沿海的气溶胶地基观测站点2008年1月7日至2009年4月30日的观测资料,对厦门海域气溶胶光学厚度的每日逐时变化、逐日变化、逐月变化进行了分析研究,并利用观测结果对MODIS L2级气溶胶光学厚度(AOT)产品进行检验。结果表明,厦门海域气溶胶光学厚度每日逐时变化和逐月变化有一定的季节规律,而逐日变化随气象条件的不同有很大差异。一年中气溶胶光学厚度月平均值呈现春秋季双峰分布趋势,4月份最大,超过0.9,空气较为混浊;6月份呈现谷值,AOT小于0.3,空气相对清洁。夏季气溶胶主控粒子的粒径较大,而其余各月份的波长指数在平均值1.21附近波动,混浊系数年平均值为0.25。利用该地基观测资料对MODIS L2级AOD产品进行检验,MODIS反演的厦门海域气溶胶光学厚度逐月变化趋势和地基观测结果完全一致,表明MODIS卫星遥感气溶胶光学厚度能比较好地反映厦门海域的气溶胶季节变化特征。  相似文献   
84.
A three-dimensional,first order turbulence closure,thermal diffusion model is described inthis paper.The governing equations consist of an equation of continuity,three components of momentum,conservation equations for salt,temperature and subgridscale energy,and an equation of state.In the mod-el,according to the hypothesis of Kolmogorov and Prandtl,the viscosity coefficient of turbulent flow ofhomogeneous fluid is related to the local turbulent energy,and the horizontal and vertical exchangecoefficients of mass,heat and momentum are computed with the introduction of subgridscale turbulenceenergy.The governing equations are solved by finite difference techniques.This model is applied to theJiaozhou bay to predict thermal pollution by the Huangdao power plant.An instantaneous tidal currentfield is computed,then the distribution of temperature increment is predicted,and finally the effect of windstress on thermal discharge is discussed.  相似文献   
85.
Spectral Characteristics of Wind-Waves in Laboratory   总被引:1,自引:1,他引:0  
Spectral characteristics of wind-generated waves in labortaory are presented on the basis of asystematic measurement in a large-scale wind-wave channel and compared with those in the field.A ma-rked characteristics of the measured spetra is the existence of secondary spectrum-peak.The dependenceof spectral peak-frequency,peak-value and zeroth-order moment on wind speed and fetch are presentedand found roughly similar to those in the field represented by the JONSWAP spectrum,regardless of thedifferences in coefficient.The spectral slope β at high-frequencies are found somewhat greater than thoseof field wind-waves in both cases of deep and shallow waters.Except for the low-frequency part,the spec-tral forms measured in different wind conditions are similar and fit for the JONSWAP spectrum with γ=6andβ=5.5.Some relevant problems are discussed.  相似文献   
86.
The erodibility of intertidal sediments is an important factor affecting coastal erosion.In July and October 2008,in situ measurement of erodibility of the surficial sediment were conducted using a recirculating flume at 20 tidal flat experiment sites along the seashore of the Yellow River delta.At the same time,the characteristics of sand ripples and biogenic features on the tidal flat were observed and the physical-mechanical sediment properties such as bulk density,water content,grain size distribution,plasticity,penetration resistance,shear strength and compressibility,were measured.By field measurement,it is obtained that the critical erosion shear stress of the surficial sediment on the tidal flat varies between 0.088 Pa and 0.254 Pa.The factors influencing sediment erodibility are complicated because of physical and biological reworking after the sediment deposited.There’s a positive correlation between shear strength and critical erosion shear stress.The burrowing crabs’ activities changed the sediment microtopography and made the sediment have greater roughness,and that is one possible reason for the higher erodibility.The formation of scour pits on the tidal flat correlates with the heterogeneous erodibility of the surficial sediment.  相似文献   
87.
In this paper,we characterize the North Yellow Sea (NYS) water masses in summer by analyzing temperature and salinity data surveyed in 2006.The Liaonan Coastal Water is characterized by low salinity westward and southward flow paths.The westward path flows parallel to land,turns to the south,then to the southeast adjacent to the mouth of the Lüshun River,where it mixes with other coastal water directly to the southwest.It becomes the main source of low salinity water in the deep water area west of 123°E.The...  相似文献   
88.
An open reading frame (lcn61) of iymphocystis disease virus China (LCDV-cn), probably responsible for encoding putative zinc-finger proteins was amplified and inserted into pET24a (+) vector.Then it expressed in E. coli BL21 (DE3), and His-tag fusion protein of high yield was obtained. It was found that the fusion protein existed in E. coli mainly as inclusion bodies. The bioinformatics analysis indicates that LCN61 is C2H2 type zinc-finger protein containing four C2H2 zinc-finger motifs. This work provides a theory for functional research of lcn61 gene.  相似文献   
89.
南海的右行陆缘裂解成因   总被引:31,自引:2,他引:31  
周蒂  俞何兴等 《地质学报》2002,76(2):180-190
南海成果是西太平洋边缘海动力学研究的重要部分,也关系到特提期,环太平洋两大超级会聚带的相互作用,是国内外地学界长期研究的热点问题。西太平洋边缘海内带,尤其是日本海和南海在形成时代,海盆形态和海底地貌,海底扩张的多轴,多阶段,由东向西扩展特征,岩石圈地幔的地球化学异常等方面具有共同特征,可能在成因上也相似,南海的海盆的楔形的楔形形状,海底扩张及陆架盆地的断陷的由北向南发展和自东向西推进的特征,地壳伸展减薄和海底扩张程度的由东向西减弱都可用尖端向西的“剪刀模型”来描述,即南海的张开是近南北向右行剪切力作用下东亚陆缘发生裂解的结果。南海张开的同时在海盆内及其西缘印支半岛上发育大量近南北向右行走滑断裂,表明当时存在区域性的近南北向右行剪切应力,而在其东缘现在看不到大型近南北向右行走滑断裂,可能是在中中新世以后受从赤道附近近滑移北上并沿马尼拉海沟仰冲的菲律宾群岛所破坏的结果。晚中生代以来,在西太平洋构造域,特提斯构造域西段(印度)及东段(澳大利亚)先后发生了朝欧亚大陆的,不同方向和速度的会聚。在这三大作用的复合和竞争的动力学背景下,东亚陆缘发生了有地幔参加传动的“超级剪切”,其应力场经历了左行压扭体制和右行张扭体制交替的阶段性变化,正是在特提斯构造域西段的会聚起主导作用的阶段,东亚陆缘在右行张扭应力场作用下发生裂解,形成了南海和其他内带边缘海。  相似文献   
90.
Based on the integrated results of multiple data types including MBES (Multi-Beam Echo Sounding) and historical topography maps,the LSR (Linear Sand Ridges) on the ECS (East China Sea) shelf are identified,divided into subareas,and classified.The distribution of sand ridge crests is also established.The strikes of the LSR on the ECS shelf fall in a normal distribution with the center point being 155° azimuth with additional peak points at 125°,130°,140°,and 180° azimuth.The distribution of the ECS shelf san...  相似文献   
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