磁异常三维解析信号所揭示的中国东部及邻近海域岩浆岩特征     

张少武  李春峰 《物探与化探》2011,35(3):290-297

根据中国东部及邻近海域总磁异常计算的三维解析信号振幅值比总磁异常,能精确地刻画磁源体的位置、深度和边界。结果显示在中国东部地区不同构造块体内的岩浆岩深度差异很大,华北块体的磁异常解析信号振幅值较高、尺度大,磁源体埋深达10 km左右或更深,反映了这个古老克拉通块体的中—下地壳内部较为强烈的岩浆活动过程与活化。受构造抬升和岩浆上涌影响,苏鲁—大别造山带的岩浆岩体埋深则相对较浅,多小于5 km。中、下扬子块体的岩浆岩体的埋深也普遍较大,但是岩浆活动微弱,解析信号振幅值很低。受晚中生代古太平洋俯冲的影响,华南块体及其东北海域分布比较孤立的岩浆岩体,其深度大都小于5 km。在东海,受新生代张裂作用的影响,岩浆岩体的深度与基底隆起或沉降呈明显对应关系。琉球群岛对应平静的磁异常并显示较深的岩浆岩体分布,表明琉球群岛不是菲律宾海板块俯冲形成的火山弧而可能是由俯冲增生楔物质和部分从欧亚大陆分离出来的块体构成,其西侧的岩浆岩带才是真正的火山弧。  相似文献   

2010上海世博会上欧泊营销的启示     

余芳  包德清 《地质科学译丛》2011,(1):43-46

欧泊是一种具有特殊光学效应的宝石,其变幻莫测的色彩令人着迷。但在国内珠宝市场上欧泊的销售份额很小,有关其有效营销方法研究方面的参考资料基本处于空白状态。借助2010年上海世博会的契机,结合笔者在澳大利亚馆销售欧泊产品4个月的经历,着重从多角度吸引顾客、留住顾客、销售攻心术、灵活引导及创新推广活动等方面分析了澳大利亚AODC公司的营销策略,从中总结出几点建议,旨在对国内珠宝营销有所启发。  相似文献   

示波极谱法测量电锌液中微量镍   总被引：1，自引：0，他引：1  

杨毅  黄晓林 《云南地质》2011,30(1):105-106

提出在丁二酮肟-亚硝酸钠-氨水-氯化铵体系中,准确测定电锌液中微量镍的新方法:克服原子吸收光谱法测定微量镍回收率偏低问题。  相似文献   

台湾海峡西部沉积物中碳的来源及埋藏   总被引：4，自引：1，他引：3  

叶翔  陈坚  王爱军  黄财宾  汪卫国  李东义 《海洋学报》2011,33(5):73-82

根据2005年夏季航次观测的沉积物中总有机碳(TOC)、无机碳(CaCO3)、总氮(TN)、悬浮体颗粒有机碳(POC)、沉积物粒度数据得出,台湾海峡西部表层沉积物TOC质量分数的范围为0.01～1.79,平均值为0.37±0.24,略高于20多年前台湾海峡南部海区,而低于台湾海峡中、北部海区;TOC的质量分数湾内比湾外...  相似文献   

Wave groupiness and spectral bandwidth as relevant parameters for the performance assessment of wave energy converters     

Jean-Baptiste Saulnier  Alain Clément  Teresa Pontes  Pierpaolo Ricci 《Ocean Engineering》2011,38(1):130-147

To date the estimation of long-term wave energy production at a given deployment site has commonly been limited to a consideration of the significant wave height H_s and mean energy period T_e. This paper addresses the sensitivity of power production from wave energy converters to the wave groupiness and spectral bandwidth of sea states. Linear and non-linear systems are implemented to simulate the response of converters equipped with realistic power take-off devices in real sea states. It is shown in particular that, when the converters are not much sensitive to wave directionality, the bandwidth characteristic is appropriate to complete the set of overall wave parameters describing the sea state for the purpose of estimating wave energy production.  相似文献   

Large-scale experiments on beach profile evolution and surf and swash zone sediment transport induced by long waves,wave groups and random waves   总被引：1，自引：0，他引：1  

T.E. Baldock  J.A. Alsina  I. Caceres  D. Vicinanza  P. Contestabile  H. Power  A. Sanchez-Arcilla 《Coastal Engineering》2011

New large-scale laboratory data are presented on the influence of long waves, bichromatic wave groups and random waves on sediment transport in the surf and swash zones. Physical model testing was performed in the large-scale CIEM wave flume at UPC, Barcelona, as part of the SUSCO (swash zone response under grouping storm conditions) experiment in the Hydralab III program (Vicinanza et al., 2010). Fourteen different wave conditions were used, encompassing monochromatic waves, bichromatic wave groups and random waves. The experiments were designed specifically to compare variations in beach profile evolution between monochromatic waves and unsteady waves with the same mean energy flux. Each test commenced with approximately the same initial profile. The monochromatic conditions were perturbed with free long waves, and then subsequently substituted with bichromatic wave groups with different bandwidth and with random waves with varying groupiness. Beach profile measurements were made at half-hourly and hourly intervals, from which net cross-shore transport rates were calculated for the different wave conditions. Pairs of experiments with slightly different bandwidth or wave grouping show very similar net cross-shore sediment transport patterns, giving high confidence to the data set. Consistent with recent small-scale experiments, the data clearly show that in comparison to monochromatic conditions the bichromatic wave groups reduce onshore transport during accretive conditions and increase offshore transport during erosive conditions. The random waves have a similar influence to the bichromatic wave groups, promoting offshore transport, in comparison to the monochromatic conditions. The data also indicate that the free long waves promote onshore transport, but the conclusions are more tentative as a result of a few errors in the test schedule and modifications to the setup which reduced testing time. The experiments suggest that the inclusion of long wave and wave group sediment transport is important for improved near-shore morphological modeling of cross-shore beach profile evolution, and they provide a very comprehensive and controlled series of tests for evaluating numerical models. It is suggested that the large change in the beach response between monochromatic conditions and wave group conditions is a result of the increased significant and maximum wave heights in the wave groups, as much as the presence of the forced and free long waves induced by the groupiness. The equilibrium state model concept can provide a heuristic explanation of the influence of the wave groups on the bulk beach profile response if their effective relative fall velocity is larger than that of monochromatic waves with the same incident energy flux.  相似文献   

Virtual wave gauges based upon stereo imaging for measuring surface wave characteristics     

Adam J. Bechle  Chin H. Wu 《Coastal Engineering》2011

A virtual wave gauge (VWG) technique based on stereo imaging is developed to remotely measure water wave height, period, and direction. VWG minimizes computational costs by directly tracking the elevation of the water surface at selected points of interest using a Eulerian based dynamic searching algorithm. Results show that the VWG technique developed in this paper dramatically improves efficiency by two orders of magnitude compared to the traditional Lagrangian–Eulerian based point cloud method of stereo image processing. VWG is tested against traditional wave wire gauges to within 98% accuracy for significant wave height. Furthermore, the flexibility of the VWG is demonstrated in two field applications. First in an offshore breaking wave case, an array of VWGs is used to efficiently measure wave directionality. Second to investigate the reflection coefficient of a rock-mounted structure interacting with nearshore waves, linear and spatial VWG arrays are designed and implemented based on a priori information of the wave field from a preliminary VWG measurement. Overall, we demonstrate that the flexible and computational efficient VWG technique has the potential to make real-time remote stereo imaging wave measurements a reality.  相似文献   

An empirical formula for friction coefficient of a perforated wall with vertical slits     

Kyung-Duck Suh  Yeul Woo KimChang-Hwan Ji 《Coastal Engineering》2011

The friction coefficient in the permeability parameter of a perforated wall has been estimated on the basis of a best fit between measured and predicted values of such hydrodynamic coefficients as reflection and transmission coefficients. In the present study, an empirical formula for the friction coefficient is proposed in terms of known variables, i.e., the porosity and thickness of the perforated wall and the water depth. This enables direct estimation of the friction coefficient without invoking a best fit procedure. To obtain the empirical formula, hydraulic experiments are carried out, the results of which are used along with other researchers' results. The proposed formula is used to predict the reflection and transmission coefficients of various types of structures including a perforated wall. The concurrence between the experimental data and calculated results is good, verifying the appropriateness of the proposed formula. It is also shown that the proposed formula can be used for irregular waves as well.  相似文献   

Evaluation of wave impact loads on caisson breakwaters based on joint probability of impact maxima and rise times     

Giovanni Cuomo  Rodolfo Piscopia  William Allsop 《Coastal Engineering》2011

When waves break against seawalls, vertical breakwaters, piers or jetties, they abruptly transfer their momentum into the structure. This energy transfer is always spectacular and perpetually unrepeatable but can also be very violent and affect the stability and the integrity of coastal structures. Over the last 15 years, increasing awareness of wave-impact induced structural failures of maritime structures has emphasised the need for a more complete approach to dynamic responses, including effects of impulsive loads. At the same time, movement of design standards toward probabilistic approaches requires new statistical tools able to account for uncertainties in the variability of wave loading processes. This paper presents a new approach to the definition of loads for use in performance design of vertical coastal structures subject to breaking wave impacts.  相似文献   

Measured and modeled wave overtopping on a natural beach     

Natalie A. Laudier  Edward B. ThorntonJamie MacMahan 《Coastal Engineering》2011

The rate of wave overtopping of a barrier beach is measured and modeled. Unique rate of wave overtopping field data are obtained from the measure of the Carmel River, California, lagoon filling during a time when the lagoon is closed-off with no river inflow. Volume changes are based on measured lagoon height changes applied to a measured hypsometric curve. Wave heights and periods are obtained from directional wave spectra data in 15 m fronting the beach. Beach morphology was measured by GPS walking surveys. Three empirical overtopping models by Van der Meer and Janssen (1995), Hedges and Reis (1998) and Pullen et al. (2007) with differing parameterizations on wave height, period and beach slope and calibrated using extensive laboratory data obtained over plane, impermeable beaches are applied in a quasi-2D manner and compared with the field observations. Three overtopping events are considered when morphology data were available less than 2 weeks prior to the event. The models are tuned to fit the data using a reduction factor to account for beach permeability, berm characteristics, non-normal wave incidence and surface roughness influence. In addition, the run-up model by Stockdon et al. (2006) based on field data is examined and found to underestimate run-up as the calculated values were too small to predict any of the observed overtopping. The three overtopping models performed similarly well with values of 0.72–0.87 for the two narrow-banded wave cases, with an average reduction factor of 0.78. The European model (Pullen et. al., 2007) performed best overall and in particular for the case of the broad-banded, double peaked wave spectrum.  相似文献