Modelling nitrogen and phosphorus cycles and dissolved oxygen in the Zhujiang Estuary Ⅰ. Model development   总被引：1，自引：0，他引：1  

Guan Weibing  Wong Lai-Ah  Xu Dongfeng 《海洋学报(英文版)》2001,20(4):493-504

wrmcrloxHuman activities related to the population growth and developrnent of industry and rnwhci-pality have led to the incrouing hadings of various POllutants into estudries during the past fewdecades. These increasing edlutant lOadings have caused declined estuallne hedth which can bemereured by a vdriety of indices. In order to obtain solutions to environrnent problerns, re-sources manageTnnt apencies are supporting a holistic approach to envirorirnental management.An effcient strategy t…  相似文献   

Vertical variations of wave-induced radiation stress tensor   总被引：3，自引：0，他引：3  

Zheng Jinhai  Yan Yixin 《海洋学报(英文版)》2001,20(4):597-605

INTRODUcrIONThe concept of radiation stress was deve1oPed by tonguet--Higgins and Stewart (1964 ),who intreduced the definition of radiation stress as the excess mornentum due to the presence ofwaves, on the basis of time-averaged laws of Newtonian fluid mechanics and the assmption ofa unifOrm velocity distribution over depth. Subequently, the theory has been applied success-fully in the investigation of phenomena such as wave set-up and set--down (Bowen et al.,l968), longshore currents …  相似文献   

Sensitivity to stress of the estuarine bivalve Macoma balthica from areas between the Netherlands and its southern limits (Gironde)     

H. Hummel  C. Amiard-Triquet  G. Bachelet  M. Desprez  J. Marchand  B. Sylvand  J.C. Amiard  H. Rybarczyk  R.H. Bogaards  J. Sinke  Y. De Wit  L. De Wolf 《Journal of Sea Research》1996,35(4):315-321

Variation in the sensitivity to stress of Macoma balthica was measured in several French and Dutch estuaries. For adult and juvenile Macoma balthica exposed to copper under conditions of starvation, differences in mortality rate, condition, glycogen, burrowing rate and copper content were assessed. No significant differences were observed between adults and juveniles; the influence of treatment and origin was always evident. Animals from the most southern estuaries, Loire and Gironde, near to the species's southern limit of distribution, showed, in the field, the strongest deviations for the ecophysiological traits measured, and were in the experiments the most sensitive to stress.  相似文献   

三峡及邻区晚第三纪以来构造应力场特征探讨     

贾永刚  单红仙 《海洋科学》1995,19(2):36-41

用三峡及邻区（东经１０８°～１１３°，北纬２９°～３３°）地质资料，地震资料，现 场地应力测量资料论证三峡及邻区晚第三纪以来构造应力场稳定性及其分区特 征。  相似文献   

正压浅海湍流运动的雷诺应力封闭模型     

徐肇廷  楼菁  鹿有余 《中国海洋大学学报(自然科学版)》1991,(3)

根据湍流封闭理论,建立一种适用于正压浅海湍流运动的雷诺应力封闭模型(RSM),以代替目前三维浅海动力学模型中普遍采用的湍粘性系数的传统假设。通过直接建立并模化f—平面上正压海洋的雷诺应力传输方程,分别得到的微分形式和代数形式的RSM方程组。并讨论了进行数值计算所需要的边界条件。利用该模型可以进一步研究浅海潮流、风暴潮流及风海流等浅海流动的三维结构和湍流特性。  相似文献   

The Mathematical and Parameterized Expressions for Wave Induced Excess Flow of Momentum     

朱首贤丁平兴  张文静 《中国海洋工程》2007,21(1):137-146

Wave induced excess flow of momentum(WIEFM)is the averaged flow of momentum over a wave period due to wave presence,which may also be called 3-D radiation stress.In this paper,the 3-D current equations with WIEFM are derived from the averaged Navier-Stokes equations over a wave period,in which the velocity is separated into the large-scale background velocity,the wave particle velocity and the turbulent fluctuation velocity.A concept of wave fluctuating layer(WFL)is put forward,which is the vertical column from the wave trough to wave ridge.The mathematical expressions of WIEFM in WFL and below WFL are given separately.The parameterized expressions of WIEFM are set up according to the linear wave theory.The integration of WIEFM in the vertical direction equals the traditional radiation stress(namely 2-D radiation stress)given by Longuet-Higgins and Stewart.  相似文献   

大鹏澳海域水体磷的形态及其分布特征     

彭云辉  王肇鼎 《热带海洋学报》1996,(2)

根据１９９２年１２月（冬季）和１９９３年７月（夏季）对大鹏澳海域２４ｈ定点连续观测和夏季大面调查，统计了该海域各种形态磷的变化范围和平均含量；计算了各种形态磷分别占总磷（ＴＰ）和总溶解磷（ＴＤＰ）的百分比；讨论了各种形态磷之间的相互关系；分析了影响ＴＰ和ＴＤＰ分布的环境因素。  相似文献   

锶诱导的氧化胁迫对叉鞭金藻(Dicrateria inornata)的影响   总被引：3，自引：2，他引：3  

李梅  徐瑾  刘志礼  徐俊 《海洋与湖沼》2004,35(5):467-472

采用不同浓度的锶胁迫方法研究了叉鞭金藻生长、叶绿素、MDA含量及三种抗氧化酶SOD、CAT、GPX活性的变化。结果表明，在实验设计的各种Sr^2 浓度内叉鞭金藻均能生长，但Sr^2 浓度较高时生长受到不同程度的抑制，细胞数量比对照组分别减少15．9％和51．0％；叉鞭金藻中叶绿素含量随着Sr^2 浓度的升高而降低，呈负相关关系；叉鞭金藻中MDA含量在较低Sr^2 浓度下稍呈下降趋势，但与对照组相比并无显著差异，而在23．04mmol／L Sr^2 浓度时是对照的1．25倍；低Sr^2 浓度时，叉鞭金藻中蛋白质含量没有大的变化，当浓度超过5．76mmol／L时则引起蛋白质含量下降；叉鞭金藻中抗氧化酶SOD在低Sr^2 时分别降低12．5％、7．5％和9．5％，高Sr^2 时显著升高，为对照组的85．7％；CAT、GPX活性在低Sr^2 浓度时差别不大，但当浓度为23．04mmol／L时升高显著，比对照组分别增加了19．8％和74．4％。  相似文献   

A Note on Soil Structure Resistance of Natural Marine Deposits   总被引：1，自引：1，他引：1  

洪振舜刘松玉  刘志方 《中国海洋工程》2004,18(2):321-326

It has been well documented that natural normally-consolidated marine soils are generally subjected to the effects of soil structure. The interpretation of the resistance of soil structure is an important issue in the theory study and engineering practice of ocean engineering and geotechnical engineering. It is traditionally considered that the resistance of soil structure gradually disappears with increasing stress level when the applied stress is beyond the consolidation yield stress. In this study, however, it is found that this traditional interpretation of the resistance of soil structure can not explain the strength behavior of natural marine deposits with a normally-consolidated stress history A new interpretation of the resistance of soil structure is proposed based on the strength behavior. In the preyield state, the undrained strength of natural marine deposits is composed of two components: one developed by the applied stress and the other developed by the resistance of soil structure. When the applied stress is beyond the consolidation yield stress, the strength behavior is independent of the resistance of soil structure.  相似文献   

Effect of emersion and immersion on the porewater nutrient dynamics of an intertidal sandflat in Tokyo Bay   总被引：2，自引：0，他引：2  

Tomohiro Kuwae  Eiji Kibe  Yoshiyuki Nakamura 《Estuarine, Coastal and Shelf Science》2003,57(5-6):929-940

Porewater nutrient dynamics during emersion and immersion were investigated during different seasons in a eutrophic intertidal sandflat of Tokyo Bay, Japan, to elucidate the role of emersion and immersion in solute transport and microbial processes. The water content in the surface sediment did not change significantly following emersion, suggesting that advective solute transport caused by water table fluctuation was negligible. The rate of change in nitrate concentration in the top 10 mm of sediments ranged from −6.6 to 4.8 μmol N l⁻¹ bulk sed. h⁻¹ during the whole period of emersion. Steep nutrient concentration gradients in the surface sediment generated diffusive flux of nutrients directed downwards into deeper sediments, which greatly contributed to the observed rates of change in porewater nutrient concentration for several cases. Microbial nitrate reduction within the subsurface sediment appeared to be strongly supported by the downward diffusive flux of nitrate from the surface sediment. The stimulation of estimated nitrate production rate in the subsurface layer in proportion to the emersion time indicates that oxygenation due to emersion caused changes in the sediment redox environment and affected the nitrification and/or nitrate reduction rates. The nitrate and soluble reactive phosphorus pools in the top 10 mm of sediment decreased markedly during immersion (up to 68% for nitrate and up to 44% for soluble reactive phosphorus), however, this result could not be solely explained by molecular diffusion.  相似文献