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1.
The comparison of spatial and temporal distribution of Hg, Cd, Pb, Cu, Ni, Zn, Mn and Fe concentrations in sediments from the Gulf of Riga and open Baltic Sea along the coastal zone is presented for the first time. There were considerable differences in Pb, Zn, Mn and Fe levels in sediment at various stations of the Gulf of Riga. A significant difference of Cd, Pb, Cu, Ni, Zn levels was found in sediments of various stations in the open Baltic coast. The amount of Cd, Pb, Cu, Ni, Zn and Fe levels also differed significantly in the sediments of the Gulf of Riga in different years. A considerable yearly difference in amount of Hg, Cd, Pb, Cu, Ni and Mn levels was found in sediments in the open Baltic coast. The essential highest values of Pb and Zn in coastal sediments of the open Baltic Sea are stated in comparison with the Gulf of Riga. The concentrations of other metals have only a tendency to be higher in coastal sediments of the open Baltic Sea in comparison with the Gulf of Riga. Natural and anthropogenic factors were proved to play an important role in determining resultant metals concentrations in the regions. 相似文献
2.
Yu. D. Chashechkin 《Physical Oceanography》2011,20(5):317-324
The methods of perturbation theory and integral representations are used to analyze the general properties of a system of
equations of the mechanics of inhomogeneous fluids including the equations of momentum, mass, and temperature transfer. We
also consider various submodels of this system, including the reduced systems in which some kinetic coefficients are equal
to zero and degenerate systems in which the variations of density or some other variables are neglected. We analyze both regularly
perturbed and singularly perturbed solutions of the system. In the case of reduction or degeneration of solutions, the order
of the system decreases. In this case, regularly perturbed solutions are preserved (with certain modifications) but the number
of singularly perturbed components participating in the formation of the boundary layers on contact surfaces and their analogs
in the bulk of the fluid, i.e., the elongated high-gradient interlayers, decreases. The interaction between all components
of the currents is nonlinear, despite the fact that their characteristic scales are different. 相似文献
3.
Analysis of characteristics and mechanism of current system on the west coast of Guangdong of China in summer 总被引：1，自引：2，他引：1
On the basis of data of drifting bottles＇ tracks and the current measured in anchored stations, as well as temperature and salinity observed in cruise investigations and coastal stations, ADCP current data and AVHRR surface sea temperature （SST） data on the western coast of Guangdong, synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer, which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits. Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits. The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer. The summertime＇s coastal current was always westward, maybe temporarily turning northeast only when the southwest wind was strong. The important characteristics of coastal current on the western coast of Guangdong, in the Qiongzhou Straits and in the north of the Beibu Gulf were analyzed and their mechanisms also were explained. 相似文献
4.
V. L. Dorofeev 《Physical Oceanography》2000,11(2):117-131
Within the framework of a two-layer model, we consider the process of, formation of livel in a closed basin under the action
of a source with constant flow rate located on its boundary in the upper layer. The response of the level of the basin to
the inflow of liquid is observed in the form of the baroclinic and barotropic modes. The baroclinic mode, has the form of
an edge wave for which the deviation of level is positive for the upper layer and negative for the lower layer. The barotropic
component of the level is almost spatially homogeneous and its intensity increases with time. The increase in the volume of
the upper layer caused by the inflow of liquid on the boundary is almost completely attained in the barotropic mode. In the
lower layer, the increase in the volume attained in the barotropic mode is completely compensated by the baroclinic edge wave.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
5.
Particular features of the tectonic structure and anomalous distribution of the geothermal, geomagnetic, and gravity fields in the region of the Sea of Okhotsk are considered. On the basis of heat flow data, the ages of large-scale structures in the Sea of Okhotsk are estimated at 65 Ma for the Central Okhotsk Rise and 36 Ma for the South Okhotsk Basin. The age of the South Okhotsk Basin is confirmed by the data on the kinematics and corresponds to a 50-km thickness of the lithosphere. This is in accordance with the thickness value obtained by magnetotelluric soundings. A comparative analysis of the model geothermal background and the measured heat flow values on the Akademii Nauk Rise is performed. The analysis points to an abnormally high (by approximately 20%) measured heat flow, which agrees with the high negative gradient of gravity anomalies. The estimates of the deep heat flow and the basement age of the riftogenic basins in the Sea of Okhotsk were carried out in the following areas: the Deryugin Basin (18 Ma, Early Miocene), the TINRO Basin (12 Ma, Middle Miocene), and the West Kamchatka Basin (23 Ma, Late Oligocene). The temperatures at the boundaries of the main lithological complexes of the sedimentary cover are calculated and the zones of oil and gas generation are defined. On the basis of geothermal, magnetic, structural, and other geological-geophysical data, a kinematic model of the region of the Sea of Okhotsk for a period of 36 Ma was calculated and constructed. 相似文献
6.
V. Martins E. Ferreira da Silva C. Sequeira F. Rocha A.C. Duarte 《Estuarine, Coastal and Shelf Science》2010
Aveiro is a town with 80,000 inhabitants situated in the central west coast of Portugal. It is located at the centre of the Ria de Aveiro, a coastal lagoon that functions as a multi-estuarine area. This town is crossed by several canals which are connected with lagoon channels through canal locks. The operation of the canal locks influences the hydro dynamism in Aveiro's canal and this and other human activities have left a sedimentary record. The study of these records was based on the sediments grain size and composition, mineralogy (by XRD techniques), geochemical (by ICP-MS), total organic carbon (TOC), and microfaunal (benthic foraminifera) content in 15 grab-samples collected in 2006 in Aveiro's canal. The total elemental concentrations evaluated by total digestion of the sediment fraction <2000 μm revealed the presence of “hot spots” of pollution caused by heavy metal contaminants in some Aveiro canals, related to legacies of past industrial activities. These “hot spots” have, for instance, higher available concentrations of Al, Cd, Co, Cu, Fe, Pb, Mn and Zn (evaluated by sequential chemical extractions) and are located in Paraíso, Alboi, Botirões and Cojo Canals, at sites where the sediments are finer and richer in TOC. Abiotic and biotic variables submitted to principal component analysis and cluster analysis highlights the hydrodynamics and human effects on the system and the negative influence of pollutants on the benthic organisms (foraminifera). 相似文献
7.
本文根据我国台湾海洋工作者的调查分析资料，对台湾近海的温、盐垂直分布及ｔ－Ｓ图解特征进行分析，按其相似性特点进行归类和分型，并探讨它们的特点和异同之处。主要结果如下：１．冬、夏季台湾近海的温、盐垂直分布类型有５种，ｔ－Ｓ图解类型为９种。２．冬季台湾近海的水温垂直分布存在着一层、二层、三层结构，夏季多为三层结构；冬、夏季的盐度垂直分布为二层和三层结构。３．台湾西南、南和东北近海，ｔ－Ｓ图解类型复杂，出现多种类型交错。４．夏季台湾南端的猫鼻头、鹅銮鼻沿岸附近，其温、盐垂直分布皆出现上均匀层，此现象实属少见。 相似文献
8.
目的：探讨人参醇提物及其沉淀对小鼠肠道菌群的影响。方法：利用环磷酰胺制备免疫低下小鼠模型,以人参水提物为对照,观察人参醇提物及其沉淀对小鼠肠道菌群的影响;肠道菌群数据采用Flash 1.2.11、Qiime 1.9.1、Mothur 1.30.2及PICRUSt 1.1.0等软件分析。结果：通过样本多样性指数分析,发现小鼠十二指肠、结肠、直肠所在部位肠道菌群结构差异具有统计学意义（P＜0.05或P＜0.01）。群落组成分析得知,小鼠肠道菌群差异较大的是Firmicutes(厚壁菌门),Bacteroides(拟杆菌门),Proteobacteria (变形菌门)与 Epsilonbacteraeota,Actinobacteria(放线菌门),Tenericutes(柔壁菌门)等。物种差异分析显示,免疫低下模型小鼠直肠部位的Epsilonbacteraeota数量显著增多(P=0.02),表明菌群失调;人参能调节肠道菌Epsilonbacteraeota失衡,其功效由大到小依次为人参水提物、醇提物及其沉淀。功能预测显示,肠道菌群结构改变,其对应的基因功能信息也改变,免疫低下模型小鼠直肠菌群结构与数量改变,引起RNA processing and modification, Chromatin structure and dynamics, Energy production and conversion 等方面基因改变。结论：免疫低下小鼠肠道菌群结构与功能改变,人参的不同提取物及其沉淀对小鼠肠道菌群有一定的影响。 相似文献
9.
鹿角珊瑚人工养殖的初步研究 总被引：1，自引：0，他引：1
为了探讨珊瑚人工养殖的基本条件和方法,分别在陆基水泥池中和海底珊瑚苗床上对3种鹿角珊瑚:粗野鹿角珊瑚(Acropora humilis)、霜鹿角珊瑚(Acropora pruinosa)和松枝鹿角珊瑚(Acropora brueggemanni)的人工养殖进行了实验。结果表明,这3种珊瑚可以在深圳市鹅公湾近岸海域的海底珊瑚苗床上常年生长;在水泥池中当水温低于14℃或高于28℃时珊瑚陆续死亡;这3种珊瑚的生长速度在适温范围内随着水温的升高而加快,最大月生长值是6.05 mm;光照对这3种珊瑚的生长有影响,直接的阳光照射会引起水泥池中珊瑚的死亡。 相似文献
10.
The reproduction of dynamic processes in the stratosphere at extratropical latitudes is considered in calculations of the atmospheric module of the global climate model of the Institute of Numerical Mathematics, Russian Academy of Sciences, with an upper boundary of 0.2 hPa (~60 km) for the period from 1979 to 2008 in comparison with the data observational. Changes in temperature, zonal wind, activity of planetary waves, heat fluxes in the lower stratosphere, and sudden stratospheric warmings with the displacement and splitting of the polar vortex, as well as the distribution of associated circulation anomalies in the troposphere, are analyzed. 相似文献
11.
We analyzed long-term (56-year) variations in springtime biomass of the zooplankton of the California Current System from two primary regions sampled by CalCOFI: Southern California (SC) and Central California (CC) waters. All organisms were enumerated from the plankton samples and converted to organic carbon biomass using length-carbon relationships, then aggregated into 19 major taxa. Planktonic copepods dominate the carbon biomass in both SC (59%) and CC (46%), followed by euphausiids (18% and 25% of mean biomass in SC and CC, respectively). Pelagic tunicates, especially salps and doliolids, constituted a higher fraction of the biomass in CC (13%) than in SC (5%). There was no long-term trend detectable in total zooplankton carbon biomass, in marked contrast to a decline in zooplankton displacement volume in both regions. The difference between these biomass metrics is accounted for by a long-term decline in pelagic tunicates (particularly salps), which have a relatively high ratio of biovolume:carbon. The decline in pelagic tunicates was accompanied by a long-term increase in water column density stratification. No other taxa showed a decline over the duration of the study, apart from salps and pyrosomes in SC and doliolids in CC. Some zooplankton taxa showed compensatory increases over the same time period (ostracods, large decapods, and calycophoran siphonophores in both SC and CC; appendicularians and polychaetes in SC). Two tests for ecosystem shifts, a sequential algorithm and the cumulative sum of anomalies (CuSum) approach, failed to detect changes in 1976-1977 in total carbon biomass, displacement volume, or most individual major taxa, suggesting that aggregated biomass is an insensitive indicator of climate forcing. In contrast, both techniques revealed a cluster of step-like changes associated with the La Niña of 1999. The major El Niño’s in the past half century have consistently depressed total zooplankton biomass and biomass of many major taxa in both SC and CC, although such effects are transitory. Much, but not all, of the interannual variability in zooplankton is shared between the Southern and Central California sectors of the California Current System. 相似文献
12.
G. N. Baturin 《Oceanology》2012,52(5):666-676
The lithology and geochemistry of the Miocene concretional phosphorites recovered from four submarine rises in the Sea of Japan (the North and South Yamato, the East Korean, and the Krishtofovich) were examined by means of analytical electron microscopy and ICP-MS chemical and microchemical elemental analysis. The microstructural studies and the data on the distributions of the 57 major and trace elements in these phosphorites revealed their close similarities to the Late Quaternary nodular phosphorites from the Namibian shelf, as well as phosphorites from other parts of the world, thus suggesting a common genetic affinity. Unlike the Namibian phosphorites, our samples collected from the Sea of Japan display a number of geochemical signatures indicative of volcanic and hydrothermal activity. This is supported by the presence of positive Ce and Eu anomalies in some samples and the Ga enrichment in a sample from the Chentsov Volcano. 相似文献
13.
Ünsal Istemi 《Ocean Engineering》1979,6(5):517-526
This study deals with the propagation of surge waves in open channels. The governing equations are derived for an arbitrary cross-section and specific solutions are given for rectangular, parabolic, and trapezoidal cross-sections. The method can be applied in each case, where the relation between the level and the area is known in advance. The hypotheses are the same as in classical treatises of surge waves, but the derived equations in dimensionless parameters show the possibility of plotting graphs for the given profile, which allows the finding of the solution in each case without a trial-and-error procedure, as with the classical method.The same equations show that (a) in the case of positive waves generated at the upstream side of a channel, two of the three defined parameters can have any prescribed value and the third can readily be found; (b) in the case of positive waves generated at the downstream end, an inequality must hold in order that the third parameter has a physical interpretation. 相似文献
14.
建立了珠江口海域三维悬浮泥沙的非饱和输沙数学模型,并与珠江口三维水动力斜压模型耦合,对悬沙迁移分布进行了模拟。模型由4个点的逐时实测含沙量过程进行了验证。各点模拟含沙量与实测含沙量吻合较好,表层分布与同期珠江口悬沙分布遥感图像基本一致.模拟结果表明,珠江口海域悬沙分布分层明显,河口附近水域大多为底层含沙量大于表层,但在盐淡水交汇处出现中层含沙量最小的情况总体上,自各个口门输出的泥沙受沿岸流作用向西南万向输送明显。大多数河口落潮时相对涨潮时含沙量等值线外移,反映珠江口水域悬浮泥沙主要来自河流。 相似文献
15.
Numerical Study of the Generation and Propagation of Trigger Meanders of the Kuroshio South of Japan
We examine the processes underlying the generation and propagation of the small meander of the Kuroshio south of Japan which occurs prior to the transition from the non-large meander path to the large meander path. The study proceeds numerically by using a two-layer, flat-bottom, quasi-geostrophic inflow-outflow model which takes account of the coastal geometries of Kyushu, Nansei Islands, part of the East China Sea, and the Izu Ridge. The model successfully reproduces the observed generation and propagation features of what is called "trigger meander" until it passes by Cape Shiono-misaki; presumably because of the absence of the bottom topography, the applicability of the present numerical model becomes questionable after the trigger meander passes by Cape Shiono-misaki. The generation of the trigger meander off the south-eastern coast of Kyushu is shown to be associated with the increase in the supply of cyclonic vorticity by the enhanced current velocity in the upper layer along the southern coast of Kyushu where the no-slip boundary condition is employed. Thereafter, the trigger meander propagates eastward while inducing an anticyclone-cyclone-cyclone pair in the lower layer. The lower-layer cyclone induced in this way, in particular, plays a crucial role in intensifying the trigger meander trough via cross-stream advection in the upper layer; the intensified trigger meander trough then further amplifies the lower-layer cyclone. This joint evolution of the upper-layer meander trough and the lower-layer cyclone indicates that baroclinic instability is the dominant mechanism underlying the rapid amplification of the eastward propagating trigger meander. 相似文献
16.
The motion response of marine structures in waves can be studied using finite-dimensional linear-time-invariant approximating models. These models, obtained using system identification with data computed by hydrodynamic codes, find application in offshore training simulators, hardware-in-the-loop simulators for positioning control testing, and also in initial designs of wave-energy conversion devices. Different proposals have appeared in the literature to address the identification problem in both time and frequency domains, and recent work has highlighted the superiority of the frequency-domain methods. This paper summarises practical frequency-domain estimation algorithms that use constraints on model structure and parameters to refine the search of approximating parametric models. Practical issues associated with the identification are discussed, including the influence of radiation model accuracy in force-to-motion models, which are usually the ultimate modelling objective. The illustration examples in the paper are obtained using a freely available MATLAB toolbox developed by the authors, which implements the estimation algorithms described. 相似文献
17.
亚洲沙尘对三种海洋微藻生长的影响 总被引：2，自引：0，他引：2
实验研究了采自亚洲沙尘暴源地的4种沙尘及1种采自青岛的沙尘对不同海洋微藻生长的影响,结果表明在营养盐贫乏的条件下,沙尘的添加对旋链角毛藻(Chaetoceros curvisetus),小角毛藻(Chaetoceros minutissimus)和东海原甲藻(Prorocendrum donghaiense)的生长具有明显的促进作用.与不加沙尘的对照组相比,指数生长期的比生长速率明显升高;其中取自青岛的沙尘对3种藻类的影响最明显;内蒙古锡林郭勒盟正蓝旗的沙尘营养盐含量最低,但是由于其可溶性Fe的溶出量最高,其促进作用也比较显著.在营养盐充足的条件下,沙尘的添加对3种微藻生长的影响均不显著.因此亚洲沙尘输送到西北太平洋海域可能对该海域的初级生产力具有显著的影响. 相似文献
18.
根据板东构造板东4井等长兴组钻探资料,对长兴组的生物礁进行了研究。研究表明板东构造长兴组储集岩有生物（屑）泥晶灰岩-含生物（屑）泥晶灰岩、礁灰岩和白云岩。综合储集岩物性特征、区域钻、测井资料及野外剖面,总结了生物礁的形成与演化模式及模式各部位所对应的岩性和物性。通过地震响应特征、反演等技术建立了长兴组储层识别模式,利用对应速度、Landmark属性提取的储层有效厚度经计算机网格化编制出了长兴组储层厚度分布预测图,与钻测井厚度对比,证实板东4井生物礁为点礁。 相似文献
19.
根据2013~2015年对沿浦湾浅海养殖区的水质进行的监测与分析资料,采用富营养化指数法和有机污染指数法对该海域海水营养状况和有机污染状况进行了评价.结果表明,该养殖区海水的溶解氧(DO)和化学需氧量(COD)含量符合国家二类海水水质标准,超过二类标准的指标为无机氮(DIN)、活性磷酸盐(PO_4~(3-)-P)和石油类.该养殖区春、冬两季水质指标超标情况较为明显,春季超标指标为无机氮和石油类,冬季超标指标为无机氮和活性磷酸盐.该养殖区的富营养化程度日趋严重,而有机污染程度总体不高. 相似文献
20.
因陆地资源逐步紧缺,人类活动向海洋进一步延伸,我国对海洋资源的认识程度和利用能力皆有显著提高,随之而来的便是部分企业和个人对海洋资源的无节制使用及开发,非法围海、占海甚至填海,致使海洋生态环境恶化,地方可持续发展存在障碍,国家海洋经济遭受损失。依据我国现有法律法规,加大对非法占有海域行为进行管控确有成效。然因在实践过程中存在政府越权审批、巨额利益驱使、惩戒力度不够等因素,使得非法占用海域现象屡禁不止,且非法占用行为发生后恢复海域原状之目的难以有效实现。为保障海洋经济、文化永续发展,应用最严格和最严密的法治保护国家海岸线和海洋生态环境安全;使行政执法与刑事规制相衔接,建立信息互联共享机制;成立专项组整治非法占用海域行为,形成示范效应,为日后打击此类案件积累经验。 相似文献