南极洲纳尔逊冰帽的某些动力学特征*

纳尔逊冰帽是南设得兰群岛的一个小冰帽,受海洋性气候影响冰帽上降水丰富,冰温较高。冰帽表面运动速度完全由冰帽表面形态和冰帽底床形态所控制,其中E剖面更为复杂。冰帽驱动应力基本小于100kPa.由V/Z～Za曲线得到在V/7为0.6～3×10^-9范围内的流动参数:n约为1;B≈4.3×10¹⁰dynescm^-2sec.这表明在低应力区,冰体流动更接近牛顿流体。     

Stabilization of Bottom Hole Temperature With Finite Circulation Time and Fluid Flow

As an alternative to finite element or finite difference modelling, analytical solutions are derived by the method of Laplace transformation and numerical results obtained for several models of the bottom hole temperature stabilization. Included in the models are the finite circulation time, the thermal property contrast between the borehole mud and the surrounding formation, and the presence of radial or lateral fluid flow in the formation, all of which are found to have significant effects on the dissipation of the thermal disturbance induced by drilling.
The mud circulation is considered to have the effect of either maintaining the borehole mud at a constant temperature or supplying a constant amount of heat per unit length per unit time to the borehole. For small circulation times, the former reduces to the 'zero circulation' model in which the mud circulation creates an instantaneous temperature anomaly at the hole bottom; for small borehole radii, the latter reduces to the line source model and the traditional 'Homer plot'.
For typical drilling operations in which the bottom hole temperatures are measured several hours to several tens of hours after the hole is shut in, the new models generally predict higher equilibrium formation temperatures than does the Horner plot. However, predictions from the various models converge if the BHTs are taken after the hole has been shut in for a period which is greater than about five times the circulation period.     

文登市地热资源现状及开发建议

文登市地热温泉资源丰富,且开发历史悠久。为更好地保护开发地热资源,文登市国土资源局确立了"有效节约和保护矿产资源,加强地热资源开发利用管理,打造中国温泉之都,构建资源节约型、环境友好型社会"的指导思想。在充分考虑区域温泉地质条件、资源勘查程度、温泉水质量及其开发利用现状的基础上,结合规划区内各地段产业结构特点、地理条件、经济发展水平及未来产业结构调整方向,按照走集约化开发、规模化发展的总体思路,全面整顿和规范文登地热资源开发秩序。通过强化温泉资源开发审批、建立勘查开发利用投入机制、加强温泉资源的勘查与保护工作和加大查处力度等措施,全面提升了地热资源开发利用水平。     

Impact of water environmental characteristics in Dry-Hot valley of Jinsha river on soil desertification

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Sedimentary characteristics and genetic mechanism of the giant ancient pockmarks in the Qiongdongnan Basin,northern South China Sea

In the late Miocene, giant ancient pockmarks, which are fairly rare globally, developed in the Qiongdongnan Basin. In this paper, to determine the sedimentary characteristics and genetic mechanism of these giant ancient pockmarks in the Yinggehai Formation of the Qiongdongnan Basin, based on high-resolution 3D seismic data and multiattribute fusion technologies, we analyzed the planar distribution and seismic facies of the ancient pockmarks and compared the characteristics of the ancient pockmar...     

凤眼莲根对东海原甲藻生长的抑制作用及机制研究

观察凤眼莲Eichhornia crassipes根粉末及丙酮提取物对东海原甲藻Prorocentrum donghaiense生长的影响,比较分析根系丙酮提取物中的化学成分以及不同成分抑藻效果,探讨凤眼莲根对藻类生长的抑制作用及其化学基础。结果显示,1.5g.L-1以上的凤眼莲根粉末可完全抑制东海原甲藻的生长。实际浓度0.019g.L-1的凤眼莲根丙酮提取物对东海原甲藻可产生50%的抑制率。N-苯基-2-萘胺浓度为1mg.L-1时,第6天对东海原甲藻的抑制率超过60%。浓度50μl.L-1时,亚油酸对东海原甲藻的抑制率超过80%。气相色谱-质谱联用(GC-MS)或高效液相色谱(HPLC)检测显示,凤眼莲根丙酮提取物中含有一定量的亚油酸和N-苯基-2-萘胺,同时还有大量的长链脂肪酸如十六酸、9-十六碳烯酸等。结果表明,凤眼莲根可显著抑制东海原甲藻的生长,N-苯基-2-萘胺、亚油酸可能是凤眼莲根抑藻的主要因子。     

Experimental Investigation of Instantaneous Properties of Wave Slamming on the Plate

The purpose of this paper is to investigate the instantaneous properties of wave slamming on the plate structure of an open structure.The advanced instantaneous measuring technique-Particle Image Velocimetry(PIV) is applied to acquire the instantaneous velocity field of wave slamming.From the cross-correlation analysis results of the images captured by the CCD camera,the flow fields of wave impacting on the structure are displayed visually,and the instantaneous whole-field fluid velocity vectors are obtained.The relation between the instantaneous peak impacting pressures and the instantaneous velocities of water particles is studied by probability analysis.     

陆坡非旋转重力羽状流的数值模拟

借助MITgcm模式使用二维非静力近似在水平方向采用不等间距网格,模拟了陆坡非旋转重力羽状流的流动。模拟显示陆坡上的重力羽状流的运动比较复杂。通过数值实验,发现改变地形或调整冷源强度都会影响沿陆坡下沉的低温高密度水的羽状流形态,潮汐亦会对重力羽状流有一定的影响。经计算发现在陆坡处,Richardson数小于1/4,宜发生Kelvin-Helmholtz不稳定性,并由卷挟导致环境流体与高密度流体混合,沿着斜坡加速下滑。     

Surface gravity wave interaction with elastic bottom

In the present paper, a hydroelastic model is developed to deal with surface gravity wave interaction with an elastic bed based on the small amplitude water wave theory and plate deflection in finite water depth. The elastic bottom bed is modelled as a thin elastic plate and is based on the Euler-Bernoulli beam equation. The wave characteristics in the presence of the elastic bed is analyzed in both the cases of deep and shallow water waves. Further, the linearized long wave equation is generalized to include bottom flexibility. A generalized expansion formula for the velocity potential is derived to deal with the boundary value problems associated with surface gravity waves having an elastic bed. The utility of the expansion formula is illustrated by demonstrating specific physical problems which will play significant role in the analysis of wave structure interaction problems. Behavior of the wave spectra are discussed in the case of closed basin having a free surface and an elastic bottom topography.