海水分光反射率与叶绿素浓度的相关分析

通过对东京湾两年度不同季节海水分光反射率与叶绿素浓度进行统计分析，结果表明，叶绿素浓度Ｃ与两谱段分光反射率之比Ｒｗ（λｊ）／Ｒｗ（λｊ）具有幂函关系Ｃ＝Ａ［Ｒｗ（λｊ）／Ｒｗ（λｊ）Ｂ。两者的对数显示出较好的线性关系，即ｌｏｇＣ＝ｌｏｇＡ＋Ｂｌｏｇ［Ｒｗ（λｊ）／Ｒｗ（λｊ）］。负相关系数达０．９９。相关方程之一为Ｃ＝３．３２９［Ｒｗ（５２０）／Ｒｗ（５５０）］－１．３８４（１９８７年６月初）．在梅雨季节之后，相关方程为Ｃ＝１２．６８［Ｒｗ（５２０）／Ｒｗ（５５０）］－２．０１０（１９８８年８月）。这表明了海湾或混浊的沿岸水质，在叶绿素浓度算法中，统计参数Ａ和Ｂ的确立，要基于不同季节不同水质的现场观测资料。     

Research on the spectral analysis and test method of period signals in monthly mean sea level

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偏振激光散斑的相关性研究

采用发送一束线偏振激光产生散斑的方法，研究线偏振激光散斑、＂平均椭圆偏振＂激光散斑以及非偏振激光散斑的相关性和精细结构。指出：当漫射器为一片毛玻璃时，散斑激光是线偏振的．其方向与入射激光束相同；当漫射器为涂无光白漆的毛玻璃时，散斑激光是部分或全部退偏的，涂层越厚，退偏越甚。对于强线偏振散斑场，当偏振方向改变时，散斑的精细结构无明显变化，即使是两个正交方向上的散斑图，也保持良好的相关性。对于非偏振散斑场，当照明激光束的偏振方向改变时．散斑精细结构有明显变化。     

Probabilistic Models for the Probability of Wave Breaking and Whitecap Coverage Based on Kinematic Breaking Criterion

More and more researches show that neither the critical downward acceleration nor the critical slope of water waves is a universal constant. On the contrary, they vary with particular wave conditions. This fact moders the models either for the probability of wave breaking B or for the whitecap coverage W based on these criteria difficult to apply. In this paper and the one which follows we seek to develop models for the prediction of both B and W based on the kinematical criterion. First, several joint probabihstic distribution functions (PDFs) of wave characteristics are derived, based on which the breaking properties B and W are estimated. The estimation is made on the assumption that a wave breaks ff the horizontal velocity of water particles at its crest exceeds the local wave celerity, and whitecapping occurs in regions of fluid where water particles travel faster than the waves. The consequent B and W depend on wave spectral moments of orders 0 to 4.Then the JONSWAP spectrum is used to represent the fetch-limited sea waves in deep water, so as to relate the probahility of wave breaking and the whitecap coverage with wind parameters. To this end, the time-averaging technique proposed by Glazman (1986) is applied to the estimation of the spectral moments involved, and furthermore, the theoretical models are compared with available observations collected from published literature. From the comparison, the averaging time scale is determined. The final models show that the probability of wave breaking as well as the whitecap coverage depends on the dimensionless fetch. The agreement between these models and the database is reasonable.     

混凝土的渗透性与耐久性

渗透性是混凝土耐久性中最重要的内容。论述了混凝土耐久性的影响因素、研究方法 ,以及混凝土渗透机理和渗透性与耐久性的关系。     

Effects of sediment properties on surface-generated ambient noise in a shallow ocean

Surface-generalized ambient noise in a shallow ocean waveguide with a sediment layer possessing a specific class of density and sound speed distributions capable of describing a realistic seabed environment is considered in this analysis. This class of non-uniform sediment layer has the density and sound speed distributions varying with respect to depth as a generalized-exponential and an inverse-square function, respectively. The study invokes a formulation developed by Kuperman and Ingenito (Kuperman, W. A., Ingenito, F., 1980. Spatial correlation of surface-generated noise in a stratified ocean. J. Acoust. Soc. Am., 67, 1988-1996.) for surface noise generation, in conjunction with the analytical solutions for the Helmholtz equation corresponding to the sediment layer, to arrive at an analytical expression convenient for numerical implementation. The intensity and spatial correlation of the noise sound field are analyzed with respect to the variation of the system parameters, including frequency, sediment layer thickness, sound speed gradient, with emphasis on the effects of sediment properties on the ambient noise field. The results have demonstrated that the intensity of the noise field is relatively sensitive to the variation of the parameters, but the spatial correlation is affected to a less extent, suggesting that the energy distribution, rather than the spatial structure, of the noise field is more susceptible to the environmental variations.     

Acoustic plane-wave scattering from a rough surface over a random fluid medium

Acoustic plane-wave scattering from a rough surface overlying a fluid half-space with a sound-speed distribution subject to a small random variation is considered. Under the assumption that the surface roughness and medium randomness are statistically independent, the scattered field may be derived by first solving for the mean field in the medium, and then incorporating with boundary-perturbation method to obtain the total mean field and the power spectral density of the scattered field. The employed algorithm is compatible to the analysis available in the existing literature so that the formulations are conveniently integrated. The results for the power spectral density have shown that the effects of medium inhomogeneities on the rough surface scattering are limited in a spectral regime where the scattered components have shallow grazing angles. The distribution of the power spectral density over the space is primarily governed by the power spectrum and correlation lengths of the rough surface.     

空间扰动引力的谱分析

基于重力场的频谱理论，给出了扰动引力在全球平均意义下的功率谱表达式，揭示了扰动引力的传播特性。通过数值试验，给出了扰动引力随高度变化规律，并分析了不同高度上，扰动引力恢复重力场的最高阶数及相应分辨率。从理论上分析了航空重力测量探测重力场中高频信息的能力，对制定飞行方案有一定参考价值。     

度量泥炭腐殖化度的一种简便方法:泥炭灰度

介绍了一种度量泥炭腐殖化程度简便易得的指标——灰度。通过将同一剖面灰度测量结果与传统的腐殖化度测量结果进行对比，发现二者的变化具有较强的相关性，说明导致二者变化的因素大致相同。泥炭赋色物质鉴定的实验表明腐殖质含量变化是引起灰度在剖面上变化的原因，从而进一步论证了用灰度值作为泥炭腐殖化程度指标的可行性。