中国古代的海洋潮汐学研究

海洋潮汐是近海岸发生的海面周期性升降现象。我国大陆和岛屿海岸线十分漫长,其中仅大陆海岸线就有18,000公里,中国古代沿海人民在与严重潮灾(风暴潮)进行旷日持久的艰苦斗争中,建立起闻名世界的雄伟海塘,修筑起潮闸。海潮之益不浅,无论在航海、军事、渔业,还是制盐、农业、工程等方面,中国古代对潮汐的利用是十分广泛,有较高水平的。正是在对海洋潮汐进行如此有成效的斗争和利用的漫长历史中,中国古代对海洋潮汐本身的研究也充分发展起来,并曾在世界历史上居于领先地位。

关于潮汐学课堂教学的研究

本文首先介绍了潮汐学的发展历史,在此基础上介绍潮汐学主要的教学内容和在教学过程应该注意的重点和难点,希望教师能够帮助学生系统地了解和掌握本门课程,切实地实现学有所专,专有所长。

关于潮汐学课堂实验教学的思考

本文介绍了潮汐学的教学内容和实验课的实验步骤以及每一步骤要达到的试验目的，希望通过实验教学帮助学生更好地理解和消化理论课知识，同时掌握潮汐观测数据处理的基本方法。

论海洋文化框架内的中国古代涉海自然科学——以海洋潮汐学发展为例

建设海洋强国是实现中华民族伟大复兴的重要组成部分,海洋文化是建设海洋强国的一面旗帜。海洋潮汐学在我国古代千年赓续,形成了"元气自然潮论"、"天体构造潮论"等重要潮论,并在长期的实践中形成了特有的海洋农业文化、海洋军事文化和观潮审美文化,体现着涉海自然科学与人文之间频繁互动,深深地烙上了海洋文化的印迹。潮汐文化所代表的古代涉海自然科学,已经融汇到了整个海洋文化之中,因此,海洋文化的构建离不开古代涉海自然科学的有力注入。

面向“两性一度”标准的潮汐学课程教学改革

以学生为中心,以提升综合素质能力为导向,依据“两性一度”标准对海洋潮汐学课程进行了教学改革。通过优化教学内容,贯通体现高阶性;以问题为导向,采用启发式教学体现创新性;重视实践训练,科教融合体现挑战度;多方式考核方式融合,优化考评体系,强化能力素质培养,促进课程教学质量和教学效果提升。实践表明,本课程教学改革增强了学生学习的主动性,加深了对课程内容的理解和应用,培养了学生的创新意识和科学思维方法,提升了学生解决复杂问题的综合能力。

基于优质线上教学资源的海洋潮汐学课程教学改革实践

优质线上课程为高等院校师生提供了宝贵的教育资源。高等院校理工类课程广泛存在课程内容多、理论性强和各个章节内容环环相扣等特点,学生学习难度大。该文以海洋潮汐学课程为例,提出将优质线上教学资源引入教学过程,充分发挥线上课程"名师名教"和线下课程"实时互动"的优势,旨在提高授课质量,解决学时不足情况下一部分学生因准备不充分而感到吃力以及另一部分学生希望增加教学内容的问题。此外,在教学过程中引入智慧教学工具雨课堂,能够解决学生学习效果反馈效率低的问题。

引潮力及其展开式的教学研究

本文主要介绍了什么是引潮力,引潮力的产生机理以及引潮力各级展开式的主要特征,并针对教学过程中常出现的问题提出了解决方案,目的在于帮助学生尽快地学习和掌握这部分理论知识。

唐代潮汐学家窦叔蒙及其《海涛志》

唐代宝应、大历年间(公元七六二——七七九年),出现了一篇研究海洋潮汐的专著——《海涛志》(亦名《海峤志》),它出自一位不知名的民间科学家窦叔蒙之手。我国古代专门论述潮汐的著作最早出现在三国时代,吴国的严畯曾写过一篇《潮水论》,早已散佚,仅在《三国志·严畯传》里保存了一个篇名。窦叔蒙的《海涛志》是我们现在能够看到的我国古代第一份潮汐学方面的专著。《海涛志》全文共六章。《全唐文》中只收录了第一章,缺其余五章。宋人欧阳修的《稽古录》中尚记载其六章篇名,并说:"余向在扬州得此志,甚爱之,张之于座右之壁,

关于康德潮汐摩擦假說的述評

康德(1724—1804)是德国古典哲学的奠基人,唯心主义哲学家。康德在其科学活动的初期,即所謂“前批判时期”,对自然科学作了許多研究。写过不少具有辯証法观点的自然科学論文和专著,主要的有:《关于活力的正确評价的思想》,《关于地球自轉問題的研究》(即潮汐摩擦的假說),《自然通史与天体理論》(其中包括星云假说),《将負的力概念引入自然科学中的研究》等等。其中影响最大的是潮汐摩擦假说和星云假说,它們的问世,不仅轰动了当时德国自然科学界,而且具有重要的哲学意义。恩格斯认为这两个假说打开了形而上学自然观的“第一个缺口”,第一次动搖了认为自然界在时间上沒有任何历史的观念等等。

船舶乘潮过浅模拟研究

为充分、合理地利用长江口自然潮位乘潮通航的潜力,为加强该水域航运的安全和计划管理,本文就其乘潮航道通过能力的模拟计算作一探讨.作者首先简略地介绍了长江口南水道的航道水文,然后以高低潮位法和调和常数法进行通航时间的模拟计算和多浅段共通乘潮时间的求解,最后根据1986年的潮汐实测资料,采用高低潮位法计算由长江口进口到鸭窝沙航段上端的每潮可通过量,并汇编列表.本研究对其他河口港的乘湖过浅也有一定的参考价值.

我国古代的潮流预报

研究海洋潮流对发展海洋事业具有重要意义。我们的祖先很早就和海洋发生密切关系,在长期的生产实践中,对海洋进行观察和研究,积累了丰富的海洋知识,逐步地认识了海洋潮流,掌握了海洋潮流的变化规律,进而进行潮流预报工作,为发展渔业生产和航海等事业服务。唐、宋以后,我国史籍中有关潮流预报的丰富记载及潮流预报表、预报图的相继问世,都充分表明我国古代在潮流预报研究中是有重大成就的。本文着重对我国古代的潮流预报表——"流水簿"和"流水指掌图"进行初步的分析,探讨其实用价值及在潮汐学史上的地位。

温州港台风风暴潮分析及其预报

一、引言潮波传播过程往往受风、气压等气象因子的作用,使得实际的潮波与单纯由天文原因引起的潮波有所区别。台风的强风与气压剧变所导致的增水称为台风风暴潮。温州港位于瓯江入海处,港区范围较大,属不正规半日潮区。

STUDY ON PREDICTION FOR TRANSPORT AND DIFFUSION OF DREDGED MATTER IN JIAOZHOU BAY, CHINA

The finite element method was used to simulate the currents of Jiaozhou Bay and the nearcoast areas, and then established the model of the transport and diffusion of suspended particulate matter there. The transport and diffusion of dredged matter near the discharging field were estimated; and the results were used to analyze the effects of the suspended particulate matter on the marine environment.

Temporal variations in internal tide multimodal structure on the continental shelf, South China Sea

Temporal variations in multimodal structures of diurnal( D_1) and semidiurnal( D_2) internal tides were investigated on the continental slope of the Dongsha Plateau, based on 2-month moored acoustic Doppler current profiler observations. Harmonic analysis indicated that the D_1 components( K_1 and O_1) dominated the internal tide field. The vertical structure of the K_1 constituent presented a first-mode structure while the M_2 constituent seemed to exhibit a high-mode structure. Amplitude spectra analysis of the current data revealed differences in baroclinic current amplitudes between different water depths. Temporal variations in modal structures ware analyzed, based on the D_1 and D_2 baroclinic tides extracted from the baroclinic velocity field with band-pass filters. Analysis showed that the magnitude of the D_1 internal tide current was much larger than the D_2 current, and temporal variations in the modal structure of the D_1 internal tide occurred on an approximately fortnightly cycle. The EOF analyses revealed temporal transformation of multimodal structures for D_1 and D_2 internal tides. The enhancement of the D_1 internal tide was mainly due to the superposition of K_1 and O_1, according to the temporal variation of coherent kinetic energy.

Tide and Current Observations in the Central Chukchi Sea During the Summer of 2012

Current data from a moored Acoustic Doppler Current Profiler （ADCP） deployed at 69°30.155N, 169″00.654″W in the central Chukchi Sea during 2012 summertime is analyzed in the present paper. Characteristics of tidal and residual currents are obtained with Cosine-Lanczos filter and cross-spectral analyses. The main achievements are as follows： 1） Along with the local inertial frequency of 12.8 h, two other peaks at -12-h and -10-d dominate the time series of raw velocity; 2） The M2 dominates the 6 resolved tide constituents with significant amplitude variations over depth and the ratios of current speed of this constituent to that of the total tidal current are 54% and 47% for u and v components, respectively. All the resolved tidal constituents rotate clockwise at depth with the exception of MM and O1. The constituents of M2 and $2 with the largest major semi-axes are similar in eccentricity and orientation at deeper levels; 3） The maximum of residual currents varies in a range of 20-30 cm s-1 over depth and the current with lower velocities flow more true north with smaller magnitudes compared to the current in surface layer. The -10d fluctuation of residual current is found throughout the water column and attributed to the response of current to the local wind forcing, with an approximate 1.4 d lag-time at the surface level and occurring several hours later in the lower layer; 4） Mean residual currents flow toward the north with the magnitudes smaller than 7 cm s-1 in a general agreement with previous studies, which suggests a relatively weaker but stable northward flow indeed exists in the central Chukchi Sea.

The importance of wave-tide-surge interaction to coastal material transport and diffusion

This study is to combine a coastal high-resolution (2′×2′) two-way coupled wave-tide-surge numerical model (including 3 main physical mechanisms) with a material transport/diffusion model for understanding the law of material transport/diffusion. Results show that the law of material trans- port/diffusion driven by background current field simulated by the coupled wave-tide-surge model is dif- ferent from that simulated by pure tide-surge, and more different from traditional ones driven by tidal current. The coupled background current should be taken into account for the simulation.

ANALYSES OF ERRORS IN MEDIUM-TERM NUMERICAL FORECAST PRODUCTS FOR THE SUBTROPICAL HIGH 1998

By statistic and dynamic analyses, we have come to the following conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast cannot have large improvement by translational corrections. (2) The important cause for the ECMWF medium-term numerical forecast to have errors in 1998 is that the astronomical tide is not included in the model. (3) Two indexes are found from which it can be judged that ECMWF medium-term numerical forecast will have errors if the astronomical tide is ignored in the model : ① When the 54.7?line under the moon of the nodical month astronomical singularities coincides with the trough-line of the subtropical jet flow from 50癊 to 150癊 on the 500 hPa level at 2000 L.T. of the same day, and is approximately vertical (α>60? with the isotherm, then the day 0 2 days after the appearance of the nodical month astronomical singularities is defined as the initial day. Then in three successive days after the initial day, ECMWF medium-term numerical forecast of the northern latitude of the 588 line at 120 癊 will have continuous errors as large as two latitudes (7/9). Otherwise, it won’t have continuous errors (13/13). ② Otherwise, if the 54.7 ?line is in the range of a low pressure between two high pressures, then there is a dispersive error on the day of the nodical month astronomical singularities (5/7). There is not any error (6/6) otherwise.

Sea Trials of a Wave Energy Converter in Strangford Lough, Northern Ireland

This paper describes a campaign of WEC （wave energy converter） testing and presents a selection of the results related to the measured motions and mooring tensions. A 1：20 physical model has been successfully deployed using a three point mooring installed at sea （Strangford Lough, NI） in 10 m depth. In calm weather the overall dynamics of mooring tensions is dominated by the tidal cycle due to the progressive lifting of the heavy chain with the increase in water depth on the flood and gradual lowering on the ebb. In flesh winds the dynamics is very complex, but can be studied with the aid of mathematical modelling. A simulation model was used to assess the dynamics of the mooring lines, and the results of open water tests have been compared with the model＇s performance. The results indicate that, in general, the model shows a reasonable agreement with the observations. The WEC＇s motions and the measured loads on the leading mooring line appear to relate to the concurrent environmental conditions. The data obtained can therefore be used for the model＇s calibration and further improvements, which is valuable for improving the WEC＇s design and operational characteristics. This may be important not only in relation to the issues of reliability and power take off, but also in terms of minimising the adverse effects of mooring lines on bottom sediments, as well as indirect effects of the eroded particles on a wide range of aquatic processes.

Mechanical Response of Saturated Geological Rock Mass under Tidal Force

In this paper, the mechanical response of saturated geological rock under tidal force is explored by poroelastic theory. First, we use the free energy formula of saturated rock under a tidal force to study the relationships of pore pressure with stress, and stress with strain. Then we analyze the relationship between rock strain and tidal potential by the equilibrium differential equations of saturated rock under tidal force. Finally, we derive the physical relationship between the two parameters （pore pressure and tidal mean stress） of saturated rock and tidal potential. The relationship shows that：pore pressure is directly proportional with tidal potential, but tidal mean stress of saturated rock is inversely proportional with tidal potential. The ratio coefficient is related not only to the Lame coefficients of rock skeletons, but also to the Blot modulus. By using this model to analyze observational well water level of C-18 well which locates in Huili, Sichuan Province, the well level response coefficient （D） was estimated. This way, we derive the Skempton coefficient （B）, the coefficient A and C which refer to the response coefficients of pore pressure and tidal stress to tidal potential respectively. Then we compare the differences among each coefficient in coupling and uncoupling conditions. It shows that for saturated rocks, the response of stress and pore pressure to earth tides is a product of coupling, and it is necessary to take into account the coupling effect when we study the mechanical response. The model will provide the basis not only for the study of mechanics and hydrodynamics of well-confined aquifer systems, and the mechanics of faulting under tidal force, but also for quantitative research of the triggering mechanism of tidal forces.