三峡库区宝塔坪滑坡形成机制研究

宝塔坪滑坡是三峡库区现有成因复杂的巨型老滑坡之一,长期以来,工程界对其形成机制一直有着不同的认识。通过详细的现场调查和对勘察资料的深入分析,基于滑坡形态和结构特征,进一步探讨了宝塔坪滑坡的形成机制和演化过程。研究发现：滑坡发育受控于巴东组三段泥灰岩内部及其与二段泥岩之间的层间错动带、坡体后部卸荷裂隙带和长江下切提供的高陡临空面。根据巴东组四段紫红色泥岩在滑坡区不同高程的分布和滑坡结构分析,滑坡形成及演化具有典型“多期活动,逐级牵引”模式。该滑坡共分3期活动历史,地质力学模式均为“临空面形成-卸荷裂隙带发育-泥化的层间错动带塑流沉陷-蠕滑拉裂-滑面贯通”。每期活动牵引后部坡体变形,进而重复前一期的变形破坏过程。     

新型水工混凝土表面防护涂层抗冻融性能研究

西部高寒地区地理位置独特,水文地质气候条件复杂,自然环境恶劣,造成该区域内水利工程混凝土材料易发生冻融劣化破坏。对此,选取课题组已研发的3种新型水工混凝土表面防护涂层材料(耐候型环氧涂层、不饱和聚酯树脂和聚脲涂层体系),进行室内加速冻融试验。试验结果表明,以环氧胶泥为底漆,聚脲材料为面漆的水工混凝土表面防护涂层的抗冻性能最优。随后在西藏地区水利水电工程进行了现场生产性试验,通过观测发现,新型聚脲材料起到了很好的抗冻防护效果。该材料有望应用于西部高寒地区水工建筑物的表面防护,提高水利水电工程建筑物的耐久性。     

The inception cavitating flows over an axisymmetric body with a blunt head-form

The inception cavitating flows around a blunt body are studied based on flow visualizations and velocity field measurements. The main purpose of the present work is to study the incipient cavity evolution and the interplay between the inception cavitation and the local turbulent flows. A high-speed video camera is used to visualize the cavitating flow structures, and the particle image velocimetry(PIV) technique is used to measure the velocity field, the vorticity, and the Reynolds stresses under non-cavitating and inception cavitating flow conditions. It is found that the appearance of visible cavities is preceded by the formation of a cluster of micro-bubbles not attached to the body surface and in a hairpin-shaped vortex structure. During its evolution, the cavity moves downstream with a lower speed. The effect of the incipient cavity is significant on the local vortical structures but slight on the timeaveraged velocity distribution. The mean Reynolds stress distributions in the turbulent shear flow can be substantially altered by the incipient cavities. The presence of the incipient cavities can lead to the production of turbulent fluctuations.     

Visualization of vortex core polarity in NiFe nanodots by tilted Fresnel images

We illustrate an approach which allows determining the out-of-plane component of the vortex core (polarity) in NiFe nanodots using Fresnel imaging in Lorentz electron microscopy. Using tilted Fresnel images, contribution of the polarity is introduced into the Fresnel image. However, this contribution is relatively small and a difference image from two symmetrically tilted Fresnel images must be used to eliminate the strong contribution from the in-plane curling magnetization and non-magnetic contrast. The sense of the polarity appears as a bipolar white-black contrast in the difference image on the tilt axis. A vortex core with a diameter of 16.5±2.5 nm is experimentally measured. Image tilting, displacement and geometrical distortion may disturb the difference image, and hence subtraction of the difference image must be aligned by cross-correlation. The method is also justified by a study of the observed contrast characteristic due to misalignment. The method is confirmed to be superior to similar approach with direct interpretation of information and more information subtracted.     

城镇河道景观规划设计研究——以都江堰博物馆园区河道景观设计为例

河道景观是城镇振兴的重要资源,开发河道景观对于提升城市环境质量、丰富城市景观内容、促进城市社会经济发展具有重要价值。自20世纪60年代环境改造运动兴起以来,城镇河道景观资源的开发受到普遍重视。出于对防洪、灌溉、航运、城市排水等因素的考虑,我国的城镇河道景观资源开发设计工作起步较晚,并且已有的河道景观开发大都千篇一律,流于形式。总结以往河道景观设计的经验教训,结合都江堰博物馆园区河道景观设计实践,提出城镇河道景观设计的思路和方法。     

NUMERICAL SIMULATION OF FLOW OVER TWO CIRCULAR CYLINDERS IN TANDEM ARRANGEMENT

In this article,the 2-D unsteady viscous flow around two circular cylinders in a tandem arrangement is numerically simulated in order to study the characteristics of the flow in both laminar and turbulent regimes.The method applied alternatively is based on the finite volume method on a Cartesian-staggered grid.The great source term technique is employed to identify the cylinders placed in the flow field.To apply the boundary conditions,the ghost-cell technique is used.The implemented computational method is firstly validated through simulation of laminar and turbulent flows around a fixed circular cylinder.Finally,the flow around two circular cylinders in a tandem arrangement is simulated and analyzed.The flow visualization parameters,the Strouhal numbers,and drag and lift coefficients are comprehensively presented and compared for different cases in order to reveal the effect of the Reynolds number and gap spacing on the behavior of the flow.The obtained results have shown two completely distinct flow characteristics in laminar and turbulent regimes.     

基于线阵扫描方式下的机车车顶状态检测方法

针对机车车顶异物存在和瓷瓶受损影响机车运行安全的问题,本文提出了基于线阵扫描方式下的机车车顶状态检测方法。论文用两台黑白线阵相机乒乓采集车顶图像,基于车速将图像校正后拼接成全景图,并利用区域划分法来划分大场景车顶图片,最后用SIFT特征点提取、改进后的RANSAC图像配准等算法与模板图匹配来定位瓷瓶、查找异物。实验结果表明该方法快速、有效,能够准确地找出检测图中的异物和定位瓷瓶。     

山美库区2011年污染物预测与入库量计算

针对山美水库库区污染物问题,对库区2011年污染物入库量进行初步计算得出流域污染物入库量及主要污染源,建议采取工程治理措施和非工程措施相结合的方法削减入库污染负荷,供山美水库流域水源地水污染防治实施参考。并能通过实施水生态系统保护与修复技术工程的建设,解决目前危害水源地安全的重大问题,推动山美水库水源地保护工作的全面开...     

基于肤色特征的人脸检测算法的研究

通过对比面部识别技术的各种算法,本文重点研究了基于肤色特征的人脸检测算法。首先通过两种方法实现人脸的区域分割：基于相似度的方法和基于皮肤区域、头发区域的方法。前者通过相似度计算、二值化之后标记出人脸区域,后者利用颜色来检测人脸区域。人脸区域检测完毕之后再对其进行人脸特征的标注,最终实现面部检测。     

一种变形表面的三维测量方法

提出一种新的利用标定图像进行三维测量的方法。利用SIFT算法找到初始的对应点,然后根据这些点生成三维空间中的种子点,再以这些种子点为中心,向外区域增长,直到完成整个物体表面测量。在每次增长的过程中,需要计算增长的三维空间平面在两个相机上的投影之间的图像相关系数。图像相关系数较大时认为是正确的增长,否则是错误的增长。实验证明,使用该方法能够得到很好的三维测量结果。