基于移不变全方向角提升的遥感图像降噪

在分析遥感图像结构特征及其与噪声之间主要区别的基础上,利用图像信号的方向信息,提出基于移不变全方向角提升小波（TI—OL）抑制遥感图像噪声的方法。该方法在方向提升小波变换的基础上并利用循环平移,Gabor小波滤波器和图像旋转技术改进了方向提升小波在图像去噪过程中存在的三个弊端：缺乏移不变性质,图像局部方向信息判方法断缺乏噪声鲁棒性和变换方向分布有限。消除去噪结果中的吉布斯效应,提高图像方向信息判断的准确性并保证图像纹理方向始终落在方向提升能最优表示的方向区间内。试验结果证明所提方法在处理遥感图像的过程中能在去噪的同时保留图像的细节和边缘信息,对遥感图像中的边缘信息如道路和桥梁有较好的刻画性能,较传统方法去噪性能（PSNR）和主观视觉效果（SSIM）均有较大提高。     

孙家庄铁矿初级定向钻进及防斜措施

介绍了山西省原平市孙家庄铁矿矿区的地层概况和矿体特征,收集汇总了该矿区的前期钻孔数据资料和存在的孔斜问题,对该矿区的钻孔孔斜情况及原因进行了分析,总结了该矿区的钻孔孔斜变化规律及特点,对钻探施工中的钻孔结构、钻具级配、套管选用、初级定向钻进方法及防斜措施进行了详细的介绍,并用钻探施工效果证明了采用的初级定向钻进方法和采取的防斜措施是可行和合理的。     

岌岌湖现代水下加积扇与东坷里三角洲层序地层学意义比较

对比研究东坷里三角洲（East Coulee Delta）和岌岌湖现代水下加积扇的层序地层学意义,认为：（1）东坷里三角洲发育LST—TST组合、FSST组合,其分属两个层序;（2）岌岌湖SAF发育FSST—LST—TST组合、FSST组合,亦分属两个层序;（3）两个陆相实例证明最大水泛面之后均未有高位体系域出现,可能...     

Pipe-soil shear interaction stiffness in horizontal directional drilling and pipe bursting

During horizontal directional drilling and pipe bursting installations, the shear forces between the pipe and the surrounding soil play a major role in the tensile loads and stresses experienced by the pipe. The magnitudes and variations in the shear forces are controlled by the pipe-soil interaction characteristics. This paper discusses the shear interaction between the pipe and the soil during those trenchless installations. A pipe-soil interaction mechanism is described that quantifies the relationship between the shear force and shear displacement, as well as the shear force at which sliding takes place. A simple analytical approach, as well as a finite element procedure, is employed to provide guidelines on practical values of the pipe-soil interaction stiffness and to investigate the effect of some soil and geometric parameters on the interaction stiffness magnitude.     

Kinematic transformations for planar multi‐directional pseudodynamic testing

The pseudodynamic (PSD) test method imposes command displacements to a test structure for a given time step. The measured restoring forces and displaced position achieved in the test structure are then used to integrate the equations of motion to determine the command displacements for the next time step. Multi‐directional displacements of the test structure can introduce error in the measured restoring forces and displaced position. The subsequently determined command displacements will not be correct unless the effects of the multi‐directional displacements are considered. This paper presents two approaches for correcting kinematic errors in planar multi‐directional PSD testing, where the test structure is loaded through a rigid loading block. The first approach, referred to as the incremental kinematic transformation method, employs linear displacement transformations within each time step. The second method, referred to as the total kinematic transformation method, is based on accurate nonlinear displacement transformations. Using three displacement sensors and the trigonometric law of cosines, this second method enables the simultaneous nonlinear equations that express the motion of the loading block to be solved without using iteration. The formulation and example applications for each method are given. Results from numerical simulations and laboratory experiments show that the total transformation method maintains accuracy, while the incremental transformation method may accumulate error if the incremental rotation of the loading block is not small over the time step. A procedure for estimating the incremental error in the incremental kinematic transformation method is presented as a means to predict and possibly control the error. Copyright © 2009 John Wiley & Sons, Ltd.     

沙粒不能“远走高飞”———有关“尘暴”的一条根本原理

沙与尘虽然都是岩石物理风化的产物, 但在风力作用下, 习性截然不同。拜格诺用严格的物理实验证明, 尘粒能随风远走高飞, 而沙粒却只能在地面附近跳跃前进。从北方侵袭华北平原的所谓沙尘暴, 实质上都是尘暴。对历次重大天气事件沉积物的分析, 也完全证明了这一点。因此, 尘暴物质的源头不是来自有沙, 而是有尘的地方; 从而可以使人们采取正确的治理方法。      

库水位下降条件下斜坡稳定性研究

采用核磁共振（NMR）技术反演水文地质参数,在此基础上,基于非饱和土强度理论,对现有滑坡剩余推力法进行改进。以三峡工程库区赵树岭滑坡为例,对库水位以不同速度下降时不同时刻的滑坡稳定性进行了研究,结果表明：在库水位下降过程中会出现稳定性系数达到极小值的现象。下降速度越大,稳定性极小值越小,出现极小值的时刻也相对早。     

航道对多方向波传播影响

应用Boussinesq方程对不同入射角、不同方向集中度的波浪与航道的相互作用进行模拟,得到了航道的折射影响规律以及不同入射角、不同方向集中度的波浪对航道作用的差别.结果对试验研究及工程实践有指导意义.     

非开挖铺管技术在开封-洛阳高速公路郑州东段中的应用

介绍了河南开封至洛阳高速公路郑州东段非开挖铺设电力电讯管道的施工工程,包括设备选择,施工工艺、施工中遇到的问题以及解决这些问题的办法。     

Directional spread parameter at intermediate water depth

The characteristics of directional spread parameters at intermediate water depth are investigated based on a cosine power ‘2s' directional spreading model. This is based on wave measurements carried out using a Datawell directional waverider buoy in 23 m water depth. An empirical equation for the frequency dependent directional spreading parameter is presented. Directional spreading function estimated based on the Maximum Entropy Method is compared with those obtained using a cosine power ‘2s' parameter model. A set of empirical equations relating the directional spreading parameter corresponding to the peak of wave spectrum to other wave parameters like significant wave height and period are obtained. It shows that the wave directional spreading at peak wave frequency can be related to the non-linearity parameter, which allows estimation of directional spreading without reference to wind information.