<Superscript>234</Superscript>Th/<Superscript>238</Superscript>U disequilibrium and particulate organic carbon export in the northern South China Sea

We utilized ²³⁴Th, a naturally occurring radionuclide, to quantify the particulate organic carbon (POC) export rates in the northern South China Sea (SCS) based on data collected in July 2000 (summer), May 2001 (spring) and November 2002 (autumn). Th-234 deficit was enhanced with depth in the euphotic zone, reaching a subsurface maximum at the Chl-a maximum in most cases, as commonly observed in many oceanic regimes. Th-234 was in general in equilibrium with ²³⁸U at a depth of ∼100 m, the bottom of the euphotic zone. In this study the ²³⁴Th deficit appeared to be less significant in November than in July and May. A surface excess of ²³⁴Th relative to ²³⁸U was found in the summer over the shelf of the northern SCS, most likely due to the accumulation of suspended particles entrapped by a salinity front. Comparison of the ²³⁴Th fluxes from the upper 10 m water column between 2-D and traditional 1-D models revealed agreement within the errors of estimation, suggesting the applicability of the 1-D model to this particular shelf region. 1-D model-based ²³⁴Th fluxes were converted to POC export rates using the ratios of bottle POC to ²³⁴Th. The values ranged from 5.3 to 26.6 mmol C m⁻²d⁻¹ and were slightly higher than those in the southern SCS and other oligotrophic areas. POC export overall showed larger values in spring and summer than in autumn, the seasonality of which was, however, not significant. The highest POC export rate (26.6 mmol C m⁻²d⁻¹) appeared at the shelf break in spring (May), when Chl-a increased and the community structure changed from pico-phytoplankton (<2 μm) dominated to nano-phytoplankton (2–20 μm) and micro-phytoplankton (20–200 μm) dominated.     

中西太平洋金枪鱼围网高产渔区年间变化及其原因分析

金枪鱼类是中西太平洋海域重要的经济鱼种,其中鲣产量约占到总产量的50%。本研究利用1995-2010年16年的中西太平洋（20°S~20°N,120°E~155°W）鲣围网生产统计数据和Niño3.4海区（5°S~5°N,120°~170°W）海表温度异常数据,对这16年鲣产量最高的十大渔区（5°×5°）进行时空格局分析,讨论渔场分布差异及CPUE与ENSO指数的关系。结果表明:16年间十大作业渔区主要分布在5°S~5°N、130°~175°E区域,这十大渔区产量占总产量的比重达47.5%,其中5°S~0°、155°~160°E,0°~5°N、130°~135°E,0°~5°N、135°~140°E及5°S~0°、160°~165°E等4个渔区产量占高产渔区产量的比重均超过10%,是中西太平洋重要的鲣产区。高产渔区的分布受海表温度影响较大,在厄尔尼诺时期,高产渔区分布明显偏东,主要分布在155°~180°E海域;在拉尼娜时期,高产渔区分布明显偏西,主要分布在130°~160°E海域。     

深水海底管道铺设安全辅助系统

此次研发的铺管安全辅助系统是一套自动化、简易化、旨在提高安装经济性和安全性的实时运行安全辅助系统,通过实时数据采集及处理,达到对安装期海管强度进行实时监测目的。系统组成包括设备系统和监测软件两部分。设备为系统提供辅助决策数据源;监测软件采用C++语言编写,用于数据接收、解析,并通过OrcaFlex API调用商业有限元软件OrcaFlex为分析内核进行实时分析计算,以可视化界面输出管道应力、应变、触地点等信息,给予船上作业人员安全指导,及时作出决策。     

我国海洋可再生能源产业统计指标体系的构建

海洋可再生能源产业发展前景广阔,构建我国海洋可再生能源产业统计指标体系是开展海洋可再生能源产业运行监测和评估的前提。文章概述国际和国内海洋可再生能源产业统计的现状,总结主要特点和问题;在明确统计范围、设计原则和数据获取途径的基础上,构建我国海洋可再生能源产业统计指标体系,其中综合发展统计指标体系包括基本情况、总体规模、技术装备、运营情况和科技创新5个一级指标和38个二级指标,产业链发展统计指标体系包括装置研发、电站设计、加工制造、配套材料和设备、海上施工以及咨询服务6个一级指标和31个二级指标;最后提出建立常态化统计制度、定期更新统计指标及其数据、建立数据库以及开展产业运行监测和评估的建议,以期为我国海洋可再生能源产业的发展、管理和政策制定提供参考。     

上覆硬质保护层海底管道检测技术探讨

海底管道在油气工业中发挥着重要作用,为保障其安全运营必须定期进行检测掌握其在海底的状态。有的海底管道在铺设时为其安全考虑,在海底管道上方覆盖了抛石等硬质保护层,这样就导致在海底管道定期检测时一些检测仪器难以探测到硬质保护层下海底管道的位置和埋深,而浅地层剖面仪和磁力仪仍然可以不同程度地实现这种情况下的海底管道检测。文中对浅地层剖面仪和磁力仪的原理进行了介绍并对其在上覆抛石等硬质保护层海底管道检测中的应用进行了分析探讨。分析结果表明浅地层剖面仪和磁力仪组成的综合检测系统对上覆硬质保护层的海底管道探测有一定效果,可查明海硬质保护层下海底管道的位置和埋深,为海底管道的安全管理和维护提供数据支持,也可为其他类似海底管道检测提供参考。     

分段多项式拟合在动三轴试验数据处理中的应用

动三轴采集的试验数据点(剪应变与动剪模量和阻尼比之间)具有离散性和有限性,为方便应用需要对数据点进行拟合,但现有经验公式不一定很好吻合试验数据。为得到不同剪应变与对应的动剪模量和阻尼比之间的关系,本文利用最小二乘原理,对渤海某海洋平台地基土进行动三轴试验获得的动剪模量、阻尼比与剪切应变的数据进行了分段多项式的拟合。数据处理过程是先对剪应变值进行了压缩处理,然后再分段低次多项式拟合,得到多项式拟合参数。通过此项改进解决了正规方程解中的病态问题,且拟合效果良好。     

基于ROMS模型数值研究南海温跃层的季节变化

On the basis of the regional ocean modeling system （ROMS）, the seasonal variations of the thermocline in the South China Sea （SCS） were numerically investigated. The simulated hydrodynamics are in accordance with previous studies： the circulation pattern in the SCS is cyclonic in winter and anticyclonic in summer, and such a change is mostly driven by the monsoon winds. The errors between the modeled temperature profiles and the observations obtained by cruises are quite small in the upper layers of the ocean, indicating that the ocean status is reasonably simulated. On the basis of the shapes of the vertical temperature profiles, five thermocline types （shallow thermocline, deep thermocline, hybrid thermocline, double thermocline, and multiple thermocline） are defined herein. In winter, when the northeasterly monsoon prevails, most shallow shelf seas in the northwest of the SCS are well mixed, and there is no obvious thermocline. The deep region generally has a deep thermocline, and the hybrid or double thermocline often occurs in the areas near the cold eddy in the south of the SCS. In summer, when the southwesterly monsoon prevails, the shelf sea area with a shallow thermocline greatly expands. The distribution of different thermocline types shows a relationship with ocean bathymetry： from shallow to deep waters, the thermocline types generally change from shallow or hybrid to deep thermocline, and the double or multiple thermocline usually occurs in the steep regions. The seasonal variations of the three major thermocline characteristics （the upper bound depth, thickness, and intensity） are also discussed. Since the SCS is also an area where tropical cyclones frequently occur, the response of thermocline to a typhoon process in a short time scale is also analyzed.     

一次华南双雨带暴雨中的位涡演变与雨带间的相互作用

利用实况资料和WRF中尺度数值模式对2008年6月12日18时—14日00时的华南双雨带暴雨过程进行了数值模拟与诊断分析。结果表明:随着锋面的南压,在锋面的西南方向(广西沿海)生成一低涡,该低涡作为位涡源在中高层表现稳定,分别为锋面雨带(北雨带)与暖区雨带(南雨带)提供正位涡。南雨带对北雨带的作用主要体现在中层(112~114°E附近),南雨带中有位涡的大值向北输送,其输送过程导致两条雨带在该处相连,而在115°E以东的南雨带则无明显的输送过程。同时,北部高空槽中也有大值位涡向北雨带输送,以维持北雨带。研究还发现,本次过程中暖区暴雨与锋面暴雨雨带的结构差异明显,锋面雨带的结构与传统雨带的结构比较一致;有利于暖区暴雨降水的形势主要表现在中高层。RIP轨迹模式的结果也表明,质点在运动过程中位涡的输送源是位于广西沿海的低涡,可见该位涡源对双雨带形成有重要的作用。     

Coastline configuration and geomorphologic development mode of arc-shaped coast in South China

1IntroductionArc-shaped bays are quite common on exposed sediment coast in South China, where the crenulate-bay beaches occur with the presence of two consecutive headlands and a predominant wave approach oblique to the alignment of the upcoast and downcoast headlands (Yasso, 1965). Oblique persistent swell striking a shoreline transports sediment alongshore and sculptures a coast into arc-shaped beaches. The shoreline of beach appearance mainly consists of straight segment and shadow segment…     

贵州平坝榜上煤矿矿山环境影响分区研究

为准确划定矿山环境影响范围,有效地开展矿山环境保护与综合治理,促进矿山可持续发展,本文在详细分析贵州平坝榜上煤矿矿山环境现状存在问题的基础上,运用采掘活动过程中的安全开采深度、移动角、边界角和地下水均衡原理等理论．系统地分析和计算了榜上煤矿矿山环境影响的几类不同范围：利用上山移动角确定地质灾害危险性大区,采用边界角确定井下开采影响范围,运用“大井法”圈出疏排水影响范围。依据矿山环境问题类型影响程度．相应地划分为严重区、较严重区和较轻区等3类,并给出具体量化指标。