塔里木盆地的构造演化

从地震大剖面显示，塔里木盆地发育为手风琴式的演化史。大体上形成有3层“断-坳”结构：①震旦系的“断”，古生界-三叠系的“坳”；②侏罗系的“断”，上白垩系的“坳”；③古近系的“断”，新近系的“坳”。断陷与坳陷分别由拉张与挤压应力场所致，这种应力场的变化是由相邻洋壳板块俯冲倾角由小到大的变化所引起的。由于地壳的多旋回运动，多次发生构造沉积演变，构成了多套生储盖组合，多领域、多种圈闭类型的油气藏，从震旦系-古生界-中生界-新生界，各断陷-坳陷结构的盆地都有可能形成油气藏的地质条件。     

西太平洋暖池区热带波动的天气效应

为了探讨西太平洋暧地区热带波动的天气效应，利用1980年2－9月140°E日本静止卫星纬度时间剖面卫星云图，分析了5d和14d左右周期热带波动云的演变特征，井综合分析了14d周期的云系演变型式与流场的关系，为预报热带中期天气变化规律提供了依据；热带波动中30－60d大气低频振荡的云量变化最显著，北半球夏半年热带波动的天气压主要在10°N－0°，各半年在10°N－10°S，超过这个区域热带云量的港分布型式就有明显的变化。     

水波在软淤泥底床上的衰减

本文研究了二层流体系统中波浪的衰减。上层为理想流体，下层为粘弹性Ｖｏｉｇｔ体。导出了色散关系，计算了波浪衰减系数。对于粘性或弹性很大或很小的情况，导出了各种水深情况下近似的显式的衰减系数表示式。与精确的数值结果比较，近似程度很好。可供工程设计参考、使用。     

A phase-averaged Boussinesq model with effective description of carrier wave group and associated long wave evolution

From the phase-resolving improved Boussinesq equations (Beji and Nadaoka, Ocean Engineering 23 (1996) 691), a phase-averaged Boussinesq model for water waves is derived by more effectively describing carrier wave groups and accompanying long wave evolution with less CPU time. Linear shoaling characteristics of carrier wave equations are investigated and found to agree exactly with the analytical expression obtained from the constancy of energy flux for the improved Boussinesq equations themselves, showing that the present model equations are the results of a consistent derivation procedure regarding energy considerations. Numerical simulations of the derived equations for the single wave group and narrow-banded random waves show the validity of the present model and its high performance, especially on the CPU time.     

Effects of high-order nonlinear interactions on unidirectional wave trains

Numerical simulations of gravity waves with high-order nonlinearities in two-dimensional domain are performed by using the pseudo spectral method. High-order nonlinearities more than third order excite apparently chaotic evolutions of the Fourier energy in deep water random waves. The high-order nonlinearities increase kurtosis, wave height distribution and H_max/H_1/3 in deep water and decrease these wave statistics in shallow water. Moreover, they can generate a single extreme high wave with an outstanding crest height in deep water. High-order nonlinearities (more than third order) can be regarded as one cause of freak waves in deep water.     

Second-Order Wave Diffraction Around 3-D Bodies by A Time-Domain Method

A time-domain method is applied to simulate nonlinear wave diffraction around a surface piercing 3-D arbitrary body. The method involves the application of Taylor series expansions and the use of perturbation procedure to establish the corresponding boundary value problems with respect to a time-independent fluid domain. A boundary element method based on B-spline expansion is used to calculate the wave field at each time step, and the free surface boundary condition is satisfied to the second order of wave steepness by a numerical integration in time. An artificial damping layer is adopted on the free surface for the removal of wave reflection from the outer boundary. As an illustration, the method is used to compute the second-order wave forces and run-up on a surface-piercing circular cylinder. The present method is found to be accurate, computationally efficient, and numerically stable.     

Experimental Investigation of Instantaneous Properties of Wave Slamming on the Plate

The purpose of this paper is to investigate the instantaneous properties of wave slamming on the plate structure of an open structure.The advanced instantaneous measuring technique-Particle Image Velocimetry(PIV) is applied to acquire the instantaneous velocity field of wave slamming.From the cross-correlation analysis results of the images captured by the CCD camera,the flow fields of wave impacting on the structure are displayed visually,and the instantaneous whole-field fluid velocity vectors are obtained.The relation between the instantaneous peak impacting pressures and the instantaneous velocities of water particles is studied by probability analysis.     

Spatial Variation in the Structure of Kelp Forest Communities Along a Wave Exposure Gradient

Abstract. Four sites were sampled in kelp (Macrocysiis pyrifera) forests occupying rocky bottom habitats along a wave exposure gradient in central California. Consistent betwecn-site differences were found in the three major structural elements - the surface canopy, the undcrstory assemblage, and the ground cover/turf assemblage - of kelp forest communities. Macrocysiis pyrifera was found at all four sites. Nereucyslis tuelkeana only at the most exposed site. The understory kelps Laminaria setchellii and Pterygopltora californica were also characteristic of exposed sites. Articulated coralline algae were more abundant at exposed sites than protected, while fleshy red algae showed the opposite pattern. All four study sites were located along 8.5 km of coastline, and thus were assumed to have available to them the same species pool for colonization. The substrate composition was the same and the amount of unconsolidated substrate was similar at all four sites. We suggest that exposure to wave-generated water motion, through its influence on the surface canopy and therefore on the amount of light reaching the bottom, is responsible for these between-site differences.     

西太平洋翁通-爪哇海台晚第四纪浮游有孔虫群与古温度变化

通过对翁通-爪哇海台ODP807站的浮游有孔虫进行定量分析,结合已有的氧、碳稳定同位素数据,揭示了晚第四纪赤道西太平洋表层海水温度及上部海水垂向结构的冰期／间冰期变化特征。研究表明,自530kaBP以来,西太平洋暖池区的表层海水温度(SST)和温跃层深度(DOT)都经历过显著的变化,其中年平均SST的冰期／间冰期变化幅度达4．2℃,DOT的波动范围更是超过100m,这进一步论证了西太平洋暖池的不稳定性。频谱分析还揭示出SST和DOT变化不仅具有典型的100ka冰期／间冰期旋回,还有热带地区特有的半岁差周期,说明研究区的古海洋学变化既有高纬驱动的作用,也有热带驱动的影响。     

Experimental study of the breaking limit of multi-directional random waves passing over an impermeable submerged breakwater

This study investigates experimentally the breaking wave height of multi-directional random waves passing over an impermeable submerged breakwater. Experiments have been conducted in a three-dimensional wave basin equipped with a multi-directional random wave generator. A special type of wave gauge has been newly devised to record the water surface elevations in the breaker zone as accurately as possible. The records are analyzed to estimate the location and limit of wave breaking. Comparisons have also been made with the results of regular waves. The influence of the incident wave conditions on the breaking wave height normalized by the breakwater dimensions has been investigated. Empirical formulae have been presented to estimate the breaking limit of multi-directional random waves based on the experimental records. The formulae have been tested and found to work well not only for multi-directional random waves, but for regular waves as well.