海洋有毒甲藻Coolia monotis的研究 II.培养条件的测定

1 998年 5— 9月 ,通过培养实验 ,研究了海洋底栖性有毒甲藻Cooliamonotis人工培养生长所需的理化条件。结果表明 ,培养水体深度较小而水平横截面积较大有利于获得较高产量。温度 1 6— 3 2℃、盐度 2 4— 3 8、K培养液浓度系列 1 /8K— 2K、培养液pH为 6 .5— 9.5都可存活 ,最大指数期平均生长率为 0 .6 9division·d- 1 ,获得的最大细胞密度为 6× 1 0 4 cells·ml- 1 ,是一种适应性较强的微藻。保种条件以温度 2 4℃、盐度 3 4、培养液浓度K ,pH为8.0为佳。     

Toward a generic method for studying water renewal, with application to the epilimnion of Lake Tanganyika

We present a method, based on the concept of age and residence time, to study the water renewal in a semi-enclosed domain. We split the water of this domain into different water types. The initial water is the water initially present in the semi-enclosed domain. The renewing water is defined as the water entering the domain of interest. Several renewing water types may be considered depending on their origin. We present the equations for computing the age and the residence time of a certain water type. These timescales are of use to understand the rate at which the water renewal takes place. Computing these timescales can be achieved at an acceptable extra computer cost.The above-mentioned method is applied to study the renewal of epilimnion (i.e. the surface layer) water in Lake Tanganyika. We have built a finite element reduced-gravity model modified to take into account the water exchange between the epilimnion and the hypolimnion (i.e. the bottom layer), the water supply from precipitation and incoming rivers, and the water loss from evaporation and the only outgoing river. With our water renewal diagnoses, we show that the only significant process in the renewal of epilimnion water in Lake Tanganyika is the water exchange between the epilimnion and the hypolimnion, other phenomena being negligible.     

波浪作用下海床动力反应的数值分析

近海和离岸建筑物的基通常处于连续不断的小风浪作用之下，可将其变形视为弹性。基于二维广义Biot理论，提出了线性或非线性波浪作用下饱和弹性海床动力应应的时域有限元数值解法。静力平衡条件和Biot方程组成的边值方程可视为其特例，在比较算例中，数值计算得到的孔压和有效应力幅值沿海床深度的分布与解析解十分吻合。土骨架和孔隙流体的加速度对海床动力反应的影响很小。具体算例表明，线性波沿缓坡海床传播时，土层中超静孔压和有效应力幅值随之增大，有可能发生滑动坡坏。所提出的数值解法能够灵活地处理非线性波浪荷载，海底复杂地质条件和波浪沿缓坡传播等复杂情况。     

REE distribution in water-sediment interface system at deep ocean floor

ＲＥＥｄｉｓｔｒｉｂｕｔｉｏｎｉｎｗａｔｅｒ－ｓｅｄｉｍｅｎｔｉｎｔｅｒｆａｃｅｓｙｓｔｅｍａｔｄｅｅｐｏｃｅａｎｆｌｏｏｒ￥ＺｈａｎｇＬｉｊｉｅ；ＬｉｕＪｉｈｕａａｎｄＹａｏＤｅ（ＲｅｃｅｉｖｅｄＦｅｂｒｕａｒｙ１，１９９４；ａｃｃｅｐｔｅｄＭａｙ...     

转炉钢渣对两种对虾幼虾的急性毒性效应

初步研究了一定粒径的转炉钢渣对日本对虾（Penaeus japonicus）幼虾和中国明对虾（fenneropenaeus chinensis）幼虾的急性毒性效应。实验结果显示，当钢渣质量浓度为1.8g／L时，日本对虾幼虾96h的最高死亡率为33．33％；随着钢渣质量浓度的增加，死亡率增高；当钢渣质量浓度为18g／L时，其96h的最大死亡率达到了75％。相对于日本对虾幼虾，钢渣质量浓度为18g／L时中国明对虾幼虾96h的最高死亡率只有36．67％。运用直线内插法求出钢渣对日本对虾幼虾96h半致死浓度为1．62g／L，钢渣对日本对虾的安全浓度为0．162g／L，而在实验条件下中国明对虾幼虾的半致死浓度要明显高于日本对虾幼虾。     

思林水电站通航建筑物高边坡稳定分析和评价

应用ANSYS结构分析软件,模拟了思林水电站通航建筑物高边坡的地形、地质条件以及开挖的过程,建立边坡开挖的有限元计算分析模型,分析边坡在自然状态、分级开挖以及锚杆支护加固等工况下的应力、变形及其整体稳定性.定义单元的局部安全系数,得到了边坡开挖加固后稳定安全系数的分布.根据计算成果,指出现设计加固措施可以保证边坡稳定,无需增加其他工程措施.     

Distribution Characteristics of Sulfur and the Main Harmful Trace Elements in China’s Coal

To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China＇s coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements （Hg, Sb and Se） is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.     

Simulations of 3D DC borehole resistivity measurements with a goal-oriented <Emphasis Type="Italic">hp</Emphasis> finite-element method. Part II: through-casing resistivity instruments

We simulate direct current (DC) borehole resistivity measurements acquired in steel-cased deviated wells for the assessment of rock formation properties. The assumed data acquisition configuration considers one current (emitter) and three voltage (collector) electrodes that are utilized to measure the second difference of the electric potential along the well trajectory. We assume a homogeneous, 1.27-cm-thick steel casing with resistivity equal to 10^− 5 Ω· m. Simulations are performed with two different numerical methodologies. The first one is based on transferring two-dimensional (2D) axisymmetric optimal grids to a three-dimensional (3D) simulation software. The second one automatically produces optimal 3D grids yielded by a 3D self-adaptive goal-oriented algorithm. Both methodologies utilize high-order finite elements (FE) that are specially well-suited for problems with high-contrast coefficients and rapid spatial variations of the electric field, as it occurs in simulations that involve steel-cased wells. The method based on transferring 2D-optimal grids is efficient in terms of CPU time (few seconds per logging position). Unfortunately, it may produce inaccurate 3D simulations in deviated wells, even though the error remains below 1% for the axisymmetric (vertical) well. The method based on optimal 3D grids, although less efficient in terms of CPU time (few hours per logging position), produces more accurate results that are validated by a built-in a posteriori error estimator. This paper provides the first existing simulations of through-casing resistivity measurements in deviated wells. Simulated resistivity measurements indicate that, for a 30° deviated well, measurements in conductive layers 0.01 Ω· m) are similar to those obtained in vertical wells. However, in resistive layers (10,000 Ω· m), we observe 100% larger readings in the 30° deviated well. This difference becomes 3,000% for the case of a 60° deviated well. For this highly-deviated well, readings corresponding to the conductive formation layer are about 30% smaller in magnitude than those in a vertical well. Shoulder effects significantly vary in deviated wells.     

A coupling of mixed and discontinuous Galerkin finite-element methods for poroelasticity

In this paper, we formulate a finite-element procedure for approximating the coupled fluid and mechanics in Biot’s consolidation model of poroelasticity. We approximate the flow variables by a mixed finite-element space and the displacement by a family of discontinuous Galerkin methods. Theoretical convergence error estimates are derived and, in particular, are shown to be independent of the constrained specific storage coefficient, c _o . This suggests that our proposed algorithm is a potentially effective way to combat locking, or the nonphysical pressure oscillations, which sometimes arise in numerical algorithms for poroelasticity.