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1.
作者(1991)的理论分析和实验研究表明:对于崩波型破碎,合田的临界相对波高值(H/d)b及Michell和Miche的临界波陡值(H/L)b可作为规则波的破碎指标。基于相同的原则,通过系统的分析和实验,规则波的破碎指标可以推广应用于不规则波。  相似文献   

2.
UltrastructuralstudyofoogenesisinXiamenamphioxus¥FangYongqiangandQiXiang(ReceivedApril10,1993;acceptedJuly9,1993)Abstract:─—U...  相似文献   

3.
南黄海浮游植物与水色透明度之间相关关系的研究   总被引:1,自引:0,他引:1  
本文根据 1995 年 9 月在南黄海获取的资料,分析和讨论了该水域浮游植物现存量(叶绿素 a ( C H ))、初级生产力( P P) 和海水光学参数(透明度( S T))、水色( W C)) 之间的相关关系。分析结果表明,夏末秋初南黄海 C H 与 P P, C H 与 W C 和 P P 与 W C 以及悬浮物( S S) 与 W C 之间均有良好的正相关关系。相关式分别为: P P = 22519ln( C H ) + 48891 或 P P = 5 E- 05 C H 16464( R2 = 07037); W C = 403ln( C H ) + 89768 或 W C = 71306 C H 04747 ( R2 =07921); C H = 15437ln( S S) + 13647 或 C H = 07499 S S1252( R2 = 07223); P P =33286ln S S+ 15222 或 P P = 33029 S S05694 ( R2 = 05476); P P = 42588ln( W C) - 37071或 P P = 66512 W C08665( R2 = 06731) 以 及 S S = 14019ln( W C) - 13363   相似文献   

4.
MorphogeneticstudiesonUronychiauncinata(Protozoa,Ciliophora)duringitsasexualdivision¥SongWeibo(ReceivedAugust28,1995;accepted...  相似文献   

5.
Thewavetransformationandbreakingphenomenainshallowwater¥LiYucheng(1.DalianUniversityofTechnology,Dalian116023,China)Abstract:...  相似文献   

6.
陈荣  柴敏娟 《台湾海峡》2000,19(3):364-366
将4种不同浓度的Ca^2+溶液灌注罗非鱼嗅上皮,观测其对罗非鱼嗅电图(electrooltactogram,简称EOG)电位幅值的影响,结果表明:Ca^2+对罗非鱼EOG具双重效应,在一定浓度范围(1~4mmol/dm^3)内,随着Ca^2+对EOG的效应由抑制逐渐转向促进,表现为反应的增大与Ca^2+浓度的提高呈正相关。但当Ca^2+浓度进一步提高到8mmol/dm^3时,EOG反映减小,呈现抑制效应,本文探讨了Ca^2+影响EOG的可能机制。  相似文献   

7.
StudyonthecarbonfluxintheSouthChinaSea¥HanWuying;LinHongyingandCaiYanya(ReceivedMarch5,1995;acceptedOctober4,1995)Abstract:Ac...  相似文献   

8.
合浦珠母贝精子激活机制的初步研究   总被引:2,自引:0,他引:2  
分别用氨海水、不同盐度的氨海水、Na^+、K^+,Ca^2+、Mg^2+的氯化物及Na^+,K^+的硝酸盐和NH4Cl,NH4NO3,(NH4)2SO4和(NH4)2CO4为激活剂,对人工解剖获得的合浦珠母贝Pinctada martensii精子进行激活,实验结果表明,合浦珠母贝业郛的细胞膜离子通道这闸门控制类型,其激活途径主要是通过NH4或HCG类激素开启该闸门,发生Na和Cl的交换,使精子细  相似文献   

9.
AstudyonseawaterapparentheavymetalcomplexationcapacityintheHaikouBayChenChunhua(ReceivedOctober10,1996;acceptedApril4.1997)Ab...  相似文献   

10.
探讨Ba2+离子搀杂对(Ca0.5Sr0.5)5(PO4)3Cl:Eu2+和(Ca0.4Sr0.6)5(PO4)3Cl:Eu2+量子发光效率的影响。当用Ba2+离子代替Ca2+或Sr2+离子进入晶体时,Eu2+离子的发光特性发生改变:发射峰的峰值降低,热猝灭的温度升高。并采用位型坐标理论给予解释。根据晶体的结构特征,对占据两个不等当晶体学位置的Eu2+离子发光中心之间的能量传递进行了探讨  相似文献   

11.
For any specific wind speed, waves grow in period, height and length as a function of the wind duration and fetch until maximum values are reached, at which point the waves are considered to be fully developed. Although equations and nomograms exist to predict the parameters of developing waves for shorter fetch or duration conditions at different wind speeds, these either do not incorporate important variables such as the air and water temperature, or do not consider the combined effect of fetch and duration. Here, the wind conditions required for a fully developed sea are calculated from maximum wave heights as determined from the wind speed, together with a published growth law based on the friction velocity. This allows the parameters of developing waves to be estimated for any combination of wind velocity, fetch and duration, while also taking account of atmospheric conditions and water properties.  相似文献   

12.
本文基于唐山近海海域1#、2#浮标2017年4月至11 月实时海浪观测数据及部分风速风向数据, 对唐山近海海域波浪有效波高、有效波向、有效波周期等波参数特征进行了统计分析, 并利用origin 软件对波参数与风速、风向相关性进行了研究。研究结果表明: 1#、2# 浮标海域常浪向为SSW、SW、SSE, 常浪向有效波高均以0.2 ~ 0.4 m 小浪及3 ~ 4 s 短周期为主,有效波高1 m 以上较大波浪极少出现; 该海域波浪以风浪为主, 波浪破碎速度较快, 有效波高与风速相关性较强, 相关系数r 为0.71, 风向与波向、有效波高与周期基本无相关性, 该研究资料可为海上活动及防灾减灾提供技术依据。  相似文献   

13.
Wind and wind-generated waves were measured in a wind-wave tank. A clear transition was found in the relation between the wind speed U 10 and the wind friction velocity u * near u * = 0.2 m/s, where U 10 is the wind speed at 10 m height extrapolated from the measured wind profile in a logarithmic layer, and u * = 0.2 m/s corresponds roughly to U 10 = 8 m/s in the present measurement. Quite a similar transition was found in the relation between the spectral density of high frequency wind waves and u *. These results suggest the existence of the critical wind speed for air–sea boundary processes, which was proposed by Munk (J Marine Res 6:203–218, 1947) more than half a century ago. His original idea of the critical wind speed was based on the discontinuities in such phenomena as white caps, wind stress, and evaporation, which commonly appear at a wind speed near 7 m/s. On the basis of the results of our present study and those of earlier studies, we discuss the phenomena which are relevant to the critical wind speed for the air–sea boundary processes. The conclusion is that the critical wind speed exists and it is attributed to the start of wave breaking rather than the Kelvin–Helmholtz instability, but the air–sea boundary processes are not discontinuous at a particular wind speed; because of the stochastic nature of breaking waves, the changes occur over a range of wind speeds. Detailed discussions are presented on the dynamical processes associated with the critical wind speed such as wind-induced change of sea surface roughness and high frequency wave spectrum. Future studies are required, however, to clarify the dynamical processes quantitatively. In particular, there is a need to further examine the gradual change of breaking patterns of wind waves with the increase of wind speed, and the associated change of the structure of the wind over wind waves, such as separation of the airflow at the crest of wind waves, the turbulent stress, and wave-induced stress. Studies on the dynamical structure of the high frequency wave spectrum are also needed.  相似文献   

14.
世界大洋长历时局地风速和有效波高的统计与分析   总被引:1,自引:0,他引:1  
本文基于美国海军测地卫星高度计提供的全球范围长历时局地平均风速和有效波高资料进行统计分析,结果表明,世界大洋长历时局地平均风速和有效波高有明显的相关性,其散布点系统地位于Wilson提出的深水充分成长风浪平均风速和有效波高经验曲线之上;并从能量叠加平衡方程,近似定量估计出大洋中长历时涌浪有效波高与局地平均风速的关系。  相似文献   

15.
Results of measurements of the atmospheric turbulence in the layer between 1.5 and 21 m above sea level and the drag coefficient of the sea surface as the wind blows from a 4-km-long mountainous slope with a mean inclination of 11° are presented. The measurements of wind-speed profiles and its fluctuations at several levels, waves, and the main meteorological parameters were carried out in autumn 2005 and 2008 from a stationary platform located in the Black Sea at a distance of approximately 1 km from the southern coast of Crimea. It is shown that during weak synoptic wind a low-level wind jet develops at night over the sea with a maximum velocity up to 5–6 m/s at a level of approximately 6 m over the sea induced by the katabatic wind over the coastal slope. According to the approximate estimates, the horizontal scale of the low-level jet can reach a few tens of kilometers. This flow is characterized by the dissipation rate of the turbulence energy independent of height and low-frequency velocity fluctuations related to the gravity waves and advection of turbulence from the coast. It is shown that the lower part of the boundary layer (up to a height of 3 m) is adjusted to the sea-surface roughness. The dependencies of the drag coefficient on the wind speed or wave age are steadier than in the data for the open sea. However, the age of the waves is not a universal parameter at long and short fetches.  相似文献   

16.
We consider the influence of the sea surface state on the backscattered radar cross section and the accuracy of the wind speed retrieval from the scatterometer data. We used a joint set of radars and buoys to determine the type of sea waves. Three types of sea waves were distinguished: developing wind waves, fully developed wind waves, and mixed sea. It is shown that the retrieval error of the near surface wind speed using a one-parameter algorithm is minimal in the case of fully developed wind waves. We compared these data with the results of radio-altimeter data analysis and showed that in both cases underestimation of the retrieval wind speed exists for developing wind waves and overestimation occurs for mixed sea. A variety of swell parameters (length of the dominating wave, swell height, swell age) significantly influence the backscattered radar cross section, leading to a growth in the mean square error of the retrieved wind speed during vertical sounding (radio-altimeter data), and only slightly influence the mean square error of the scatterometer data (medium incidence angles). It is necessary to include the information about the parameters of sea waves in the algorithms and take into account the regional wave properties to increase the accuracy of wind speed retrieval.  相似文献   

17.
邓丹  周泉  马磊  李锐祥 《海洋与湖沼》2023,54(6):1529-1536
南海北部海域夏季台风活动频繁,对海上生产活动和人民生命财产安全造成极大威胁,由于台风路径的不确定性,其中心附近区域的风浪观测资料十分稀少。中国气象局(China Meteorological Administration, CMA)热带气旋最佳路径数据显示2017年10月强台风“卡努”中心经过南海北部陆坡的SF301浮标,该浮标完整记录了台风过境的风浪数据。利用浮标观测资料,分析了强台风“卡努”过境期间的风和海浪特征。观测结果表明,“卡努”经过浮标时,中心气压为959.9 hPa,风速随时间呈双峰分布,前、后眼壁区的10 min平均风速分别为30.2 m/s和24.9 m/s, 1 s极大风速分别为44.2和38.6 m/s。海浪以风浪为主,观测有效波高和最大波高最大值分别为10.8和14.3 m,滞后最大风速30 min,波向和风向变化趋势一致。台风过境期间,有效波高与海面10 m风速接近线性关系,非台风期间二者呈二次多项式关系。海浪无因次波高和周期呈幂指数关系,无论是台风期间还是非台风期间二者关系十分接近Toba提出的3/2指数律。  相似文献   

18.
通过在海口湾北部海域布置波浪观测站,对采集到的实测波浪资料进行统计和波谱分析,研究了琼州海峡波浪季节性变化特征。观测期间最大波高为5.6 m,发生在台风"莎莉嘉"经过期间。无台风影响的月份最大波高为3.0 m。年平均十分之一大波波高、年平均有效波高、年平均波高分别为0.5 m、0.4 m、0.3 m,该海域波高总体不大。波周期范围主要在2~7 s区间。研究结果表明:1)观测海区各月基本都受到东北风影响并存在东北向的波浪; 2)发现海区波浪类型主要是风浪为主的混合浪; 3)发现观测海区一直受到南海传入的长周期波影响; 4)海区风向与浪向的一致性在东北季风影响时段明显强于西南季风影响时段,风速与波高的相关性在东北季风影响时段明显强于西南季风影响时段,该现象在台风月份表现得尤其明显。  相似文献   

19.
粗糙度与风浪特征量关系的研究   总被引:2,自引:2,他引:0  
在实验室风浪槽中观测风浪和风速,研究粗糙度与波面特征量的关系,发现风浪谱宽度增加,粗糙度增大。在窄谱时,粗糙度随谱宽的增加变化不明显,当波陡降低,粗糙度降低;在宽谱时,当谱宽度增加,即使波陡降低,粗糙度仍可增大。这一结果表明,波陡不足以完全决定粗糙度。当风浪波龄增加,粗糙度呈下降趋势,但由于谱宽度对粗糙度的影响,当波龄增加,部分波浪可有较大的粗糙度。由于这一因素,在粗糙度与波龄关系的观测结果中,数据点的散落不完全由观测误差造成。  相似文献   

20.
Taylor-Grörtler vortices are longitudinal vortices resulting from a centrifugal instability. They are generated in the flow having a curved streamline with an increasing velocity in the direction of decreasing curvature.It is shown that the air flow above wind waves and swells also satisfies locally the condition of the centrifugal instability. Numerical calculations indicate the possibility of generation of Taylor-Görtler vortices on the trough of sea waves. For example, when a wind of about 12.2 m/s at 10-m level is blowing over sea waves of the wave length of 15 m like the swell, the critical water wave height beyond which the vortices may be generated is about 0.5 m, and the critical wave length and the height of center of the generated vortices are about 24 m and 3.7 m, respectively. Further, about the relations between the generation of vortices and wind waves, it is shown that the condition of their generation is satisfied at the trough of waves for early stages of the wave generation.In conclusion, it is expected that the Taylor-Görtler vortices change the wind profile along the sea surface, and also, play some part in the growth of wind waves, especially in the formation of their three dimensional structure.  相似文献   

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