湍流数值模拟中封闭模式应用的局限性

通过对琼州海峡的潮流场特征进行数值模拟，指出了选择不同的特征混合长度表达式对数值模拟结果的影响，表明了基于特征混合长度理论的流封闭模式在近海湍流数值模拟中应用的局限性。     

箱式超大型浮体结构在规则波中的水弹性响应研究

利用三维线性水弹性理论研究了箱式超大型浮体结构在正弦规则波中的动力响应，用Bernoulli-Euler梁解析解计算结构在真空中的动力特性，用弹性体三维势流理论计算结构的水动力系数，浮体结构在单位波幅规则波中的刚体运动幅值与DNV／WADAM程序的计算结果进行了比较，并给出了垂向弯曲模态的位移，弯矩随波浪频率的变化规律，由于箱式浮体结构的低阶固有频率很低，相应的弹性振型的响应与刚体运动耦合，结构在波浪中没有发现明显的低阶弹性模态谐振。     

Wave-induced seabed instability around a buried pipeline in a poro-elastic seabed

The subject of the wave–seabed–structure interaction is important for civil engineers regarding stability analysis of foundations for offshore installations. Most previous investigations have been concerned with such a problem in the vicinity of a simple structure such as a vertical wall. For more complicated structures such as a pipeline, the phenomenon of the wave–seabed–structure has not been fully understood. This paper proposes a finite-difference model in a curvilinear coordinate system to investigate the wave-induced seabed response in a porous seabed around a pipeline. Based on the present numerical model, mechanism of the wave-induced soil response is examined. Employing Mohr–Coulomb failure criterion, the wave-induced seabed instability is also estimated. The numerical results indicate the importance of the effect of pipeline on the seabed response.     

The effect of nonlinear damping and restoring in ship rolling

Many researchers have studied a wide range of nonlinear equations of motion describing a ship rolling in waves. In this study, a form of nonlinear equation governing the motion of a rolling ship subjected to synchronous beam waves is suggested and solved by the generalized Duffing's method in the frequency domain. Various representations of damping and restoring terms found in the literature are investigated and their solutions are analyzed by the above-mentioned method. Comparative results of nonlinear roll responses are obtained for four distinct vessel types at resonance conditions which constitute the worst situation. The results indicate the importance of roll damping and restoring, when constructing a nonlinear roll model. An inappropriate selection of damping and restoring terms may lead to serious discrepancies with reality, especially in peak roll amplitudes.     

从234Th的固/液分配看海洋胶体的作用

1994—1995年期间,利用β计数法实测了南沙群岛海域、南海东北部海域、厦门湾塔角附近海域和九龙江河口区共计116份海水样品中溶解态与颗粒态234Th的放射性比活度。结果表明,颗粒态234Th占总34Th的份额大小顺序为：九龙江河口区＞厦门海塔角附近海域＞南沙海域。南海东北部海域。234Th的条件分配系数Kd介于1．1×104—20×106dm3／kg之间,平均为2．2×105dm3／kdKd与总悬浮颗粒物含量（7SAN呈负相关关系：lg（Kd）＝－0．59·lg（TSM）＋5．67,这一“颗粒物浓度效应”可归因于海洋胶体物质的存在。由上述关系获得4个研究海区胶体浓度与悬浮颗粒物浓度的函数关系：Cc＝f（TSM0．59）。     

基于遗传算法的浮式防波结构物形状最优化设计

采用遗传算法作为优化手段,以透射系数为目标函数,对给定横剖面面积的浮式防波结构物在规则波中的消波性能及剖面形状进行了最优化计算研究,探讨了透射系数最小的剖面形状与波浪周期之间的关系,为浮式防波结构物的设计提供了一定的理论依据     

江蓠中类菌孢素氨基酸(MAAs)成分分析及提取研究

利用高效液相色谱技术对江蓠(Gracilariaceae)中类菌孢素氨基酸(MAAs)进行了分析,并采用响应面分析法对MAAs物质的提取工艺进行优化研究。根据正交旋转组合试验设计原理,采用四因素五水平的响应面分析法,依据回归分析确定各因素的显著程度及最优工艺条件。结果表明,江蓠中MAAs的主要成分为porphyra-334;提取温度、浸提时间、甲醇浓度及液固比为影响MAAs物质提取的显著因素。通过多元二次回归拟合模型响应面分析,得到最优工艺条件:提取温度48.12℃,液固比34∶1,甲醇浓度25%,浸提时间1.85 h,优化条件下预测提取率为4.943 mg/g;试验值为4.893 mg/g,试验值与预测值吻合较好,响应面回归模型的准确性得到验证。     

Dynamic Response Behaviors of Upright Breakwaters Under Breaking Wave Impact

- The dynamic response behaviors of upright breakwaters under broken wave impact are analysed based on the mass-damper-spring dynamic system model. The effects of the mass, damping, stiffness, natural period, and impulse duration (or oscillation period) on the translation, rotation, sliding force, overturning moment, and corresponding dynamic amplifying factors are studied. It is concluded that the ampli-ying factors only depend on the ratio of the system natural period to impulse duration (or oscillation period) under a certain damping ratio. Moreover, the equivalent static approach to breakwater design is also discussed.     

利用ADS40相机快速生成正射影像图的方法研究

介绍了ADS40相机快速生成正射影像图的方法,即利用高精度POS设备能直接定向测图的特点,省去空三T序,利用POS解算出的外方位元素和自动提取的DEM进行正射影像纠正,结合实际生产项目对成图精度进行了分析。试验结果表明,ADS40相机应用于航测生产可大幅度缩短成图周期,利用本文的生产方法可以满足正射影像图精度要求,并节省大量时问,适用于应急测绘保障。     

我国海水贝类养殖低碳效应评价

食物生产系统的碳排放占人类活动碳排放总量的 30%, 碳汇渔业是一种重要的面向人类社会高质量食物蛋白质供给 的低碳发展路径。本文基于常见的 11 种养殖贝类的固碳系数和蛋白质含量特性研究,系统评估了我国2019 年养殖牡蛎 、蛤 类、扇贝、贻贝和蚶类等在养殖周期内碳捕集特性以及对低碳发展的贡献。研究表明： (1) 11 种养殖贝类之间贝壳和软体 组织含碳量的差异并不明显,但干重比和出肉率差异显著。因此,贝类固碳量核算不能忽视种类差异。 (2)所选 11 种贝类 软体组织皆属于高蛋白食品,虾夷扇贝软体组织 (干重) 的蛋白质含量最高。针对单位质量贝类养殖,长牡蛎的碳封存贡献 度最大,而华贵栉孔扇贝提供的蛋白质最多,两者都是碳汇渔业的优势种。(3) 据估算,我国2019 年海水养殖贝类中牡蛎、蛤 类 、扇贝和蚶类总共吸收固定了约 117.98 万吨 C02,提供了 40.65 万吨蛋白质 。这些蛋白质相比于牛肉源蛋白质可减少 4 048.74 万吨 C02 当量的排放量。由于贝类固碳强度大,探索低碳可持续的贝类养殖是绿色渔业经济的重要引擎, 也是建立可持续高质量“蓝色粮仓”和生物固碳的重要路径, 将在我国低碳产业发展中发挥重要作用。