基于平面波照明的偏移成像补偿

受地下复杂构造和地震数据采集系统的影响,地震波对地下目标的照明出现不均匀,在地震数据的偏移成像中出现成像阴影.根据地震数据最小二乘偏移/反演理论,和把地震波场照明结果作为最小二乘偏移/反演中的Hessian矩阵的近似对偏移成像进行补偿的原理,提出一种应用平面波照明结果对平面波偏移成像结果进行补偿以消除偏移成像阴影的方法.这种基于平面波照明的偏移成像补偿方法相对于局部角度域的照明偏移成像补偿方法具有计算效率上的优势.     

Air flow calculation of reverse circulation drilling technique with air DTH hammer

Air DTH hammer has been successfully applied in minor-caliber solid mineral exploration,water-well drilling and other drilling areas.In order to expand the applications of the technology,the authors further studied the principle and analyzed the mechanism of reverse circulation drilling technique with air DTH hammer to get the perfect assembles of equipments by optimizing working parameters.No parameter seemed more important than the air volume because it could maintain the working performance stability.The minimum air volume is related to the parameters such as depth and pressure,which was calculated under the actual conditions.It was solved for the air injection flow tables of the air DTH Hammer working at the different pressures.According to the data tables,operators could adjust the air volume to meet the demand on this technique,which had a realistic guiding significance.So it could build up a set of systematic and complete hi-technique.     

天津滨海新区软黏土的蠕变特性及无屈服面模型研究

天津滨海新区大部分为围海造陆形成的陆域,主要为吹填土经真空预压加固的软黏土地基,具有鲜明的地域特征。其蠕变特性对该地区的建筑物和构筑物地基的变形和长期稳定性有很大影响。采用大直径原状试样进行了三轴不固结不排水蠕变试验,研究了滨海新区软黏土的蠕变变形的规律性。在此基础上建立天津滨海新区软黏土的无屈服面蠕变模型,该模型只有5个参数,各参数物理意义明确,且可以通过试验确定。采用建立的模型对试验结果进行对比分析,理论模型计算结果与试验数据的拟合曲线吻合较好。该模型可用来对软黏土地基上结构物的长期蠕变变形的发展趋势和地基稳定性进行预测。     

游客涉入对旅游目的地形象感知的影响——盎格鲁入境旅游者与国内旅游者的比较

本研究的主要目的是从维度层次探讨游客涉入对目的地形象感知的影响,并对盎格鲁入境旅游者(n = 349) 和国内旅游者(n = 292) 两个群体的影响模式进行比较。游客涉入测量使用Gursoy & Gavcar 修订的国际休闲旅游者游客涉入量表,包括娱乐/兴趣、风险可能性和风险后果3 个维度;目的地形象测量使用Baloglu 的目的地形象量表,包括认知形象和情感形象2 个成份。以桂林、阳朔作为案例地,使用多组结构模型分析方法比较两个群体的结构模型。研究发现：游客涉入对目的地形象感知有显著影响,具体表现为娱乐/兴趣显著正向影响认知和情感形象;风险后果显著负向影响认知和情感形象;风险可能性对情感形象无显著影响,国内旅游者风险可能性显著正向影响认知形象,但盎格鲁入境旅游者没有发现这种影响;2 个子样本只有娱乐/兴趣→认知形象和风险可能性→认知形象两个路径系数存在差异,其他路径系数均等值。     

Density estimation of two-phase flow with multiscale and randomly perturbed data

In this paper, we describe an efficient approach for quantifying uncertainty in two-phase flow applications due to perturbations of the permeability in a multiscale heterogeneous porous medium. The method is based on the application of the multiscale finite element method within the framework of Monte Carlo simulation and an efficient preprocessing construction of the multiscale basis functions. The quantities of interest for our applications are the Darcy velocity and breakthrough time and we quantify their uncertainty by constructing the respective cumulative distribution functions. For the Darcy velocity we use the multiscale finite element method, but due to lack of conservation, we apply the multiscale finite volume element method as an alternative for use with the two-phase flow problem. We provide a number of numerical examples to illustrate the performance of the method.     

On a power series solution to the Boussinesq equation

For certain initial and boundary conditions the Boussinesq equation, a nonlinear partial differential equation describing the flow of water in unconfined aquifers, can be reduced to a boundary value problem for a nonlinear ordinary differential equation. Using Song et al.'s (2007) [7] approach, we show that for zero head initial condition and power-law flux boundary condition at the inlet boundary, the solution in the form of power series can be obtained with Barenblatt's (1990) [2] rescaling procedure applied to the power series solution obtained in Song et al. (2007) [7] for the power-law head boundary condition. Polynomial approximations can then be obtained by taking terms from the power series. Although for a small number of terms the newly obtained approximations may be worse than polynomial approximations obtained by other techniques, any desired accuracy can be achieved by taking more terms from the power series.     

海啸波近岸共振响应的数值模拟及分析

应用有限差分方法求解非线性浅水长波方程,建立了海啸波产生和传播的二维数值模型;对太平洋地震引起的夏威夷群岛海啸波进行模拟,并将模拟结果和测站实测值进行比较,验证了模型的正确性。利用快速傅里叶变换对数值模拟结果进行谱分析,得到整个计算区域的能量谱分布,并给出了发生能量聚集的位置及相应的谱峰周期。讨论了海啸波传播到近岸时可能产生的共振响应现象,发现海啸波和近岸的共振响应不仅与近岸复杂地形有关,还与海啸波传播到近岸时的波浪入射方向有关。     

深水中大跨径斜拉桥地震响应分析

本文以某斜拉桥为例,采用基于Morison方程的附加动水质量方法研究了动水压力对深水中大跨径斜拉桥地震响应的影响,并对中国、日本和欧洲规范中动水惯性系数的取值进行了对比研究。结果表明,在深水条件下应当考虑动水压力作用对结构地震响应的影响。对比日本和欧洲规范,我国规范中动水惯性系数取值偏低,动水压力的影响偏小。     

Residual curvature migration velocity analysis for angle domain common imaging gathers

Pre-stack depth migration velocity analysis is one of the keys to influencing the imaging quality of pre-stack migration. In this paper we cover a residual curvature velocity analysis method on angle-domain common image gathers (ADCIGs) which can depict the relationship between incident angle and migration depth at imaging points and update the migration velocity. Differing from offset-domain common image gathers (ODCIGs), ADCIGs are not disturbed by the multi-path problem which contributes to imaging artifacts, thus influencing the velocity analysis. On the basis of horizontal layers, we derive the residual depth equation and also propose a velocity analysis workflow for velocity scanning. The tests to synthetic and field data prove the velocity analysis methods adopted in this paper are robust and valid.     

考虑土-结构相互作用的振动台实时子结构试验仿真分析

本文基于状态空间方程进行了实时子结构试验的初步探索,提出了一种新的实时子结构试验方法。通过simulink仿真发现,这种方法能很好地再现整体分析的结构反应。最后,对考虑土-结构相互作用的振动台实时子结构试验进行了仿真分析。