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111.
112.
Recently, some results have been acquired with the Monte- Carlo statistical experiments in the design of ocean en gineering. The results show that Monte-Carlo statistical experiments can be widely used in estimating the parameters of wave statistical distributions, checking the probability model of the long- term wave extreme value distribution under a typhoon condition and calculating the failure probability of the ocean platforms. 相似文献
113.
In this study the zinc exchange process and the reason for the non-additive exchange of δ-MnO2/montmorrillonite have been investigated. The results suggest that with pH increasing from 2 to 8, the stepwise exchange of zinc occurs on δ-MnO. and montmorrillonite in their mixture.At low pH zinc ions are bound on δ-MnO2, while at high pH, the exchange on montmorrillonite dominates the surface interaction in the mixture. The study demonstrates that the stepwise exchange and the heterogeneity of the binding sites on δ-MnO2 surface are the reason for the non-additive exchange. It is also shown that when δ-MnO2 amounts to 5 %, zinc exchange on sea sediments is controlled by 8-MnO2. 相似文献
114.
In this study, we investigate two internal wave generation methods in numerical modeling of time-dependent equations for water wave propagation, i.e., delta source function method and source term addition method, the latter of which has been called the line source method in literatures. We derive delta source functions for the Boussinesq-type equations and extended mild-slope equations. By applying the fractional step splitting method, we show that the delta source function method is equivalent to the source term addition method employing the energy velocity. This suggests that the energy velocity should be used rather than the phase velocity for the transport of incident wave energy in the source term addition method. Finally, the performance of the delta source function method is verified by accurately generating nonlinear cnoidal waves as well as linear waves for horizontally one-dimensional cases. 相似文献
115.
We develop techniques of numerical wave generation in the time-dependent extended mild-slope equations of Suh et al. [1997. Time-dependent equations for wave propagation on rapidly varying topography. Coastal Engineering 32, 91–117] and Lee et al. [2003. Extended mild-slope equation for random waves. Coastal Engineering 48, 277–287] for random waves using a source function method. Numerical results for both regular and irregular waves in one and two horizontal dimensions show that the wave heights and the frequency spectra are properly reproduced. The waves that pass through the wave generation region do not cause any numerical disturbances, showing usefulness of the source function method in avoiding re-reflection problems at the offshore boundary. 相似文献
116.
Laboratory radiotracer experiments were conducted to determine assimilation efficiencies (AE) from ingested algal food and oxic sediment particles, uptake rates from the dissolved phase, and the efflux rates of Cd, Cr and Zn in the Asiatic clamCorbicula fluminea. Among three elements, AE from both algal and sediment food was greatest for Cd, followed by Zn and Cr. The AEs of tested elements from algal food(Phaeodactylum tricornutum) were consistently higher than those from sediments at a given salinity and temperature. The influence of salinity (0, 4 and 8 psu) and temperature (5, 13 and 21¼) on the metal AEs was not evident for most tested elements, except Cd AEs from sediment. The rate constant of metal uptake from the dissolved phase (k u was greatest for Cd, followed by Zn and Cr in freshwater media. However, in saline water, thek u of Zn were greater than those of Cd. The influx rate of all tested metals increased with temperature. The efflux rate constant was greatest for Cr (0.02 d-1), followed by Zn (0.010~0.017 d-1) and Cd (0.006 d-1). The efflux rate constant for Zn in clam tissues depurated in 0 psu (0.017 d-1) was faster than that in 8 psu (0.010 d-1). Overall results showed that the variation of salinity and temperature in estuarine systems can considerably influence the metal bioaccumulation potential in the estuarine clamC. fluminea. The relatively high Cd accumulation capacity ofC. fluminea characterized by the high AE, high dissolved influx rate and low efflux rate, suggested that this clam species can be used as an efficient biomonitor for the Cd contamination in freshwater and estuarine environments. 相似文献
117.
Deformation Patterns of an Accretionary Wedge in the Transition Zone from Subduction to Collision Offshore Southwestern Taiwan 总被引:1,自引:0,他引:1
Char-Shine Liu Benoit Deffontaines Chia-Yu Lu Serge Lallemand 《Marine Geophysical Researches》2004,25(1-2):123-137
Swath bathymetry data and seismic reflection profiles have been used to investigate details of the deformation pattern in the area offshore southwestern Taiwan where the Luzon subduction complex encroaches on the passive Chinese continental margin. Distinctive fold-and-thrust structures of the convergent zone and horst-and-graben structures of the passive margin are separated by a deformation front that extends NNW-ward from the eastern edge of the Manila Trench to the foot of the continental slope. This deformation front gradually turns into a NNE–SSW trending direction across the continental slope and the Kaoping Shelf, and connects to the frontal thrusts of the mountain belt on land Taiwan. However, the complex Penghu submarine canyon system blurs the exact location of the deformation front and nature of many morphotectonic features offshore SW Taiwan. We suggest that the deformation front offshore SW Taiwan does not appear as a simple structural line, but is characterized by a series of N–S trending folds and thrusts that terminate sequentially in an en-echelon pattern across the passive Chinese continental slope. A number of NE–SW trending lineaments cut across the fold-and-thrust structures of the frontal accretionary wedge and exhibit prominent dextral displacement indicative of the lateral expulsion of SW Taiwan. One of the prominent lineaments, named the Yung-An lineament, forms the southeastern boundary of the upper part of the Penghu submarine canyon, and has conspicuous influence over the drainage pattern of the canyon 相似文献
118.
To use two small fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) and the Japanese medaka Oryzias latipes (Belloniformes) as testing models in molecular ecotoxicology, we have cloned the cytochrome P450 1A (CYP1A) gene after screening of both genomic DNA libraries, and sequenced 11,863 and 7,243 bp including all the exons and introns with promoter regions, respectively. The Rivulus and the medaka CYP1A gene consisted of seven exons (including non-coding exons) with high homology to mammals. In the promoter region, Rivulus CYP1A gene has seven xenobiotic response elements (XREs) and two metal response elements (MREs), while the Japanese medaka CYP1A gene has six XREs and four MREs. Interestingly, medaka CYP1A gene has a number of MREs at the promoter, which may affect its response on metal exposure. We describe here the gene structure of both fish CYP1A genes. 相似文献
119.
基于EOF分析对南海西北海域水体光谱特性的研究 总被引:1,自引:0,他引:1
This study presents an analysis of the spectral characteristics of remote sensing reflectance(R_(rs)) in northwestern South China Sea based on the in situ optical and water quality data for August 2018.R_(rs)was initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole R_(rs) were characterized using the empirical orthogonal function(EOF) analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95% of the variances of R_(rs) are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of R_(rs)(A-D R_(rs)-EOF_1) significantly contributed to the total variances of each R_(rs) class.In addition,the correlation coefficients between the amplitude factors of class A-D R_(rs)-EOF_1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class AR_(rs)-EOF_1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B R_(rs)-EOF_1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(a_g(λ)),whereas the spectral shape of class C R_(rs)-EOF_1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D R_(rs)-EOF_1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape. 相似文献
120.