码头系泊船舶模型试验

通过对一艘50kDWG码头系泊船舶的模型试验，得出了系泊缆绳张力随外载荷变化的一般规律，对码头系泊有一定的参考价值。     

A Finite Element Solution of Wave Forces on Submerged Horizontal Circular Cylinders

In this paper, a numerical model is established for estimating the wave forces on a submerged horizontal circular cylinder. For predicting the wave motion, a set of two-dimensional Navier-Stokes equations is solved numerically with a finite element method. In order to track the moving non-linear wave surface boundary, the Navier-Stokes equations are discretized in a moving mesh system. After each computational time step, the mesh is modified according to the changed wave surface boundary. In order to stabilize the numerical procedure, a three-step finite element method is applied in the time integration. The water sloshing in a tank and wave propagation over a submerged bar are simulated for the first time to validate the present model. The computational results agree well with the analytical solution and the experimental data.Finally, the model is applied to the simulation of interaction between waves and a submerged horizontal circular cylinder.The effects of the KC number and the cylinder depth on the wave forces are studied.     

Trial and Numerical Analysis of Specimen Pipelay

Subsea pipelay has a relatively long history. In recent years, there has been a domestic need for the laying of large diameter thin wall pipes. A land-based trial for the large diameter thin wall specimen pipe is described in this paper. Re-gression analysis is performed for the trial data and the formula derived can express the trial data very well. Numerical analysis is adopted to compute various trial conditions. Then the numerical model is revised with the trial results, which are consistent with each other. After summarization of the results of trial and numerical analysis, the characteristics are described of the spatial configuration during the laying of the pipe and it is concluded that the maximum strain appears around the center of the raised pipeline. In the end, a reference Standard, which limits the maximum stress below the yield stress is provided.     

锯缘青蟹精荚移植人工授精初探

模仿雄性锯缘青蟹第一腹肢,根据其在交配中的作用机制,采用常规滴管为材料,利用酒精灯灼热拉制一个前端弯曲、侧扁、管径大小接近第一腹肢的人工交接器.以无钙离子的人工海水作为青蟹人工授精的缓冲液,缓冲液中加入适量庆大霉素.首次对青蟹采用类似硬壳交配的方式,将成熟雄蟹贮精囊内的精荚和精液成功移植至雌蟹纳精囊中.结果表明精荚的人工移植不会破坏成熟雌蟹纳精囊的内环境,其内精子具正常受精能力.未交配雌青蟹精荚的人工移植没有正常产卵,但性腺得以促进发育,并能进行正常的生殖脱皮.     

Velocity and Sediment Concentration Profiles in Sediment-Laden Flows

A theoretical analysis of velocity profiles in sediment-laden flows is presented by means of Prandtl-Karman mixing length theorem. The study shows that the upward velocity of liquid-phase caused by settling sediment leads to the invalidity of the log-law and Rouse equation. The theoretical analysis takes into account the upward velocity and shows: 1) the mean velocity in sediment-laden flows follows the log-law, but the Karman constant reduces in the main flow region, 2) sediment concentration reduces the mixing length of fluid particles, 3) flow resistance reduces with the presence of sediment concentration, and 4) the sediment concentration profile deviates from the well know Rouse equation. The experimental data agree well with the equations derived on the basis of non-zero wall velocity. It is found that the wall-normal velocity should not be neglected for density gradient flows because it induces more than for pure water flows.     

海上溢油粒子追踪预测模型中的两种数值方法比较

在海上溢油粒子追踪预测模型中,关键的是对拉格朗日微分方程的求解。本文首先通过数值实验比较了欧拉法和龙格-库塔法求解拉格朗日溢油轨迹微分方程的优劣,然后将其应用到2005年4月3日发生在大连附近的“ARTEAGA”油轮溢油事故的油膜粒子追踪模型中。数值实验和应用结果表明,在近岸不均匀流场下,用龙格-库塔方法解拉格朗日油粒子微分方程比用欧拉法求解精度高,用龙格-库塔方法模拟“ARTEAGA”油轮轨迹及其扩散范围与实际观测更为接近,而用欧拉法模拟溢油扩散的面积偏大。     

四种/株亚历山大藻(Alexandrium)毒性的比较研究

通过对塔玛亚历山大藻(ATHK和AT-6藻株)、链状亚历山大藻(ACDH藻株)和微小亚历山大藻(AM-1藻株)的PSP毒素含量和组成以及它们分别对轮虫、黑褐新糠虾和鲈鱼存活影响的比较研究发现:塔玛亚历山大藻AT-6藻株不产生麻痹性贝毒毒素PSP,而塔玛亚历山大藻ATHK、链状亚历山大藻ACDH和微小亚历山大藻AM-1均产生PSP毒素,其总含量分别为19.74、5.395、5.57fmol/cell(2.60、0.36、1.61pgSTXeq/cell)。塔玛亚历山大藻AT-6对轮虫、黑褐新糠虾和鲈鱼这三种生物均没有不利影响;对于轮虫,塔玛亚历山大藻ATHK和链状亚历山大藻ACDH的96hLC50分别为:200和1200cells/ml,而微小亚历山大藻AM-1无不利影响;对于糠虾,塔玛亚历山大藻ATHK、链状亚历山大藻ACDH和微小亚历山大藻AM-1的96hLC50分别为7000、11000、16000cells/ml;对于鲈鱼,这三株藻的96hLC50分别为3700、4000、20000cells/ml。四株亚历山大藻对三种生物的毒性大小与其PSP毒素含量和组成无直接的相关关系,其毒性作用可能来自其他未知毒性物质。塔玛亚历山大藻ATHK不同组分分别对三种生物的毒性比较研究表明:藻细胞重悬液和藻液对三种生物的不利影响最为显著,去藻过滤液和细胞碎片对轮虫和鲈鱼没有明显影响,但糠虾的存活率有所下降;细胞内容物对轮虫和糠虾也无影响,但对鲈鱼的存活有一定影响。以上研究表明:不同亚历山大藻的毒性大小存在差别,其对不同生物的危害机制也不相同,除PSP毒素外,亚历山大藻可能还存在其他的毒性物质。     

重组斑马鱼Gli2蛋白N端肽段的表达及纯化

Hedgehog(Hh)信号及其信号传递系统在生物机体发育中起着非常重要的作用。从Hhs分泌到其靶基因收到来自Hhs的信号的过程中，包括很多步骤，而每一步骤都有不同的因子参与作用。在其传递的过程中，参与受体细胞将胞外的信号传到胞内调节其目标基因的一个重要因子是果蝇分节-极性基因cubitus in terruptus(Ci)及其脊椎动物同源基 因-G li编码的蛋白。     

水土分离生态综合治理泥石流方法探讨——以青岛市崂山区河东村泥石流治理为例

2005年9月12日,青岛市崂山区河东村发生泥石流地质灾害,其周边大面积山坡仍存在潜在泥石流隐患,有再次发生泥石流的可能。通过对河东村泥石流"致灾因子"和"主灾因子"分析,得出该区发生泥石流的短历时雨强指数KH为1550.8。泥石流产生的物源条件和水源条件是缺一不可的,是水土共同作用的结果,为避免河东村再次发生泥石流,将水土分离是至关重要的。根据现场实际情况,综合考虑各方面因素,摸索出适合河东村泥石流水土分离生态综合治理方法,即地表、地下水土分离—生物生态治理—拦挡工程相结合方法,该方法在投资少、不影响风景区景观基础上,根本治理河东村泥石流发生。     

The growth mechanism of the aragonitic stalagmite laminae from Yunnan Xianren Cave,SW China revealed by cave monitoring

Duan, W., Cai, B., Tan, M., Liu, H. & Zhang, Y. 2012 (January): The growth mechanism of the aragonitic stalagmite laminae from Yunnan Xianren Cave, SW China revealed by cave monitoring. Boreas, Vol. 41, pp. 113–123. 10.1111/j.1502‐3885.2011.00226.x. ISSN 0300‐9483. Stalagmites from Xianren Cave in Yunnan Province, SW China have visible bands of alternating compact and porous sub‐layers, which have recently been demonstrated to be annual: the compact sub‐layer consists of elongated columnar aragonites with a general longitudinal orientation (parallel to the vertical growth axis), while the porous sub‐layer is composed mainly of needle aragonites forming radiating masses. In order to understand the growth mechanism of this type of stalagmite laminae, factors that could determine the growth rate and crystal structures of modern carbonates, such as cave‐air temperature, CO₂ concentration, drip rate and the hydrochemical parameters of drip water, have been monitored systematically. In this study, we selected five active drip sites to monitor for two years at a monthly frequency. Based on the monitoring results and the analyses of stalagmite laminae, we conclude that the compact sub‐layer forms in winter, when the drip rate is moderate and the degassing is slow, continuous and prolonged. The porous sub‐layer forms in early spring, when the drip rate is lower and Mg/Ca is higher than that during the formation of the compact sub‐layer. We also found exceptionally some calcite laminae. Furthermore, we discovered modern calcites precipitating at all study sites in the first hydrologic year when the rainfall was very abundant. Therefore, it is suggested that the occurrence of localized calcites in an aragonitic stalagmite indicates an interval of higher rainfall.