陆相断陷湖盆中层序边界的形成机理及其识别特征研究

陆相断陷湖盆中层序边界是由于沉积物表面高出沉积基准面或盆地基准面、沉积物发生剥蚀或无沉积作用所形成的，其产生机理主要有边界断层停止活动、断块翘倾活动、湖盆整体抬升和湖平面下降。层序边界在地震特征上、测井曲线上、钻井剖面中的岩性、岩相特征、古生物组合、微量元素的变化上均有明显的特征。利用这些特征，在济阳坳陷下第三系中识别出9个三级层序。     

Wind turbine response to parameter variation of analytic inflow vortices

As larger wind turbines are placed on taller towers, rotors frequently operate in atmospheric conditions that support organized, coherent turbulent structures. It is hypothesized that these structures have a detrimental impact on the blade fatigue life experienced by the wind turbine. These structures are extremely difficult to identify with sophisticated anemometry such as ultrasonic anemometers. This study was performed to identify the vortex characteristics that contribute to high‐amplitude cyclic blade loads, assuming that these vortices exist under certain atmospheric conditions. This study does not attempt to demonstrate the existence of these coherent turbulent structures. In order to ascertain the idealized worst‐case scenario for vortical inflow structures impinging on a wind turbine rotor, we created a simple, analytic vortex model. The Rankine vortex model assumes that the vortex core undergoes solid body rotation to avoid a singularity at the vortex centre and is surrounded by a two‐dimensional potential flow field. Using the wind turbine as a sensor and the FAST wind turbine dynamics code with limited degrees of freedom, we determined the aerodynamic loads imparted to the wind turbine by the vortex structure. We varied the size, strength, rotational direction, plane of rotation, and location of the vortex over a wide range of operating parameters. We identified the vortex conformation with the most significant effect on the blade root bending moment cyclic amplitude. Vortices with radii on the scale of the rotor diameter or smaller caused blade root bending moment cyclic amplitudes that contribute to high damage density. The rotational orientation, clockwise or counter‐clockwise, produces little difference in the bending moment response. Vortices in the XZ plane produce bending moment amplitudes significantly greater than vortices in the YZ plane. Published in 2005 by John Wiley & Sons, Ltd.     

Modelling of Al2O3 Powder Compaction with Hot Pressing in a Rigid Die

Computer modelling of hot pressing is provided. Kinetics are described for compaction during hot pressing in a rigid die, and the change in density distribution, irreversible solid phase strain accumulation, and equivalent stresses are studied by means of the finite element method. Shrinkage during the preparation of complex-shaped articles by hot pressing pure Al₂O₃ powder in a graphite die without a protective atmosphere and the physicomechanical properties of the finished article are studied. Calculated and experimental results agree satisfactorily.     

利用Love波特性计算地基动力响应

本文利用Love波弥散特性在频域上对地基出平面振动及扭振问题进行了研究。在计算区域内结构将采用有限单元划分,而在边界上则根据Love 面波特性使用传递边界有限单元。本文同时讨论了不同模态波对结构动力响应的贡献。本文方法也适合于静力分析。     

波浪力计算中的一个新边界元方法

本文就波浪与结构物作用问题，提出了一个新的高阶边界元方法。较之Ｅａｔｏｃｋ Ｔｏｙｌｏｒ和Ｃｈａｕ的方法，本文在体内附助积分方程中应用了满足刚性水面条件和弱刚性底面条件的简单格林函数。计算速度相应地有所提高；漂浮结构的积分方程更为简洁；计算结果与Ｅａｔｏｃｋ Ｔａｙｌｏｒ和Ｃｈａｕ的方法具有几乎相同的精度和收敛速度。     

FD—TD在分析FSS中的应用

本文讨论了用FD TD分析FSS的有关问题,提出了一种适合于在任意入射角情况下分析FSS的有效吸收边界条件,分别以单层、双层FSS为例进行了计算.数值结果和矢量模式法、谱域法的结果非常一致.     

全金属反射光学系统结构的有限元分析

用有限元分析方法对全金属反射光学系统在各种受力状态下的变形、应力及固有频率做了全面的分析，并给出了结构多次优化后的分析结果。     

冷却速度对激光相变组织分布的影响

提出通过改变边界换热条件，从而改变冷却速度，达到控制激光相变硬化。实验和计算结果的比较表明，这种控制相变及其组织分布的方法能够处理激光淬火难以解决的问题。     

有耗介质中电磁波传播的时域有限差分法

在推导有耗介质中Maxwell方程差分格式的基础上,详细讨论了时域有限差分法（FDTD）中主要参数的取值原则。对总场边界条件进行了改进,使入射波的泄漏很小,且不用对总场区的4个角点单独处理。讨论了简便的PML条件,避免了Berenger完全匹配层中场分裂过程。采用文中所介绍的方法,对地下有耗介质的理论模型进行了FDTD正演模拟,模拟结果可以反映地下有耗介质的有用信息,验证了该模拟技术的正确性和可靠性。     

Precise rendering method for exact anti-aliasing and highlighting

This paper introduces the Precise Rendering Method, which generates accurately anti-aliased and highlighted images from tessellated polygons. The Precise Rendering Method first solves the aliasing problems of hidden surface removal by using the Cross Scanline Algorithm. This algorithm can exactly calculate polygon areas projected onto each pixel by using horizontal and vertical scanlines. Aliasing artifacts in shading are then prevented by the Reflection Intergration Method, which analytically integrates the intensity of reflection in the solid angle defined by surface normals at vertices of the projected area. Several synthesized images are created to show the efficiency of the Precise Rendering Method.