松辽盆地北部徐家围子断陷火山岩分布及天然气富集规律

提出一个新的带通滤波器——延拓回返垂直二次导数,该滤波器可通过调节延拓回返高度及次数来达到调频目的,以突出勘探目标层段的信息.利用该技术对松辽盆地深层勘探程度最高的徐家围子断陷的航磁资料进行目标处理,与钻井资料对比表明,经处理后的航磁资料可以较好地反映火山岩的分布特征.以航磁资料为主结合钻井、地震资料预测了徐家围子三套火山岩的平面分布.指出航磁异常梯度带是火山岩储层的发育区带,近烃源岩或沟通烃源岩的航磁异常梯度带是火山岩天然气的富集区带.该认识对今后松辽盆地的勘探部署有着十分重要的指导意义,对我国其他地区的火山岩勘探也具有借鉴意义.     

反射地震数据的逐层波形反演

本文针对层状介质并结合梯度法波形反演,提出逐层波形反演的方法. 首先给出介质扰动响应的概念,并在此基础上分析了梯度法波形反演方法. 波形反演实质上是将实测地震记录和预测地震记录的波形残差信息转化为实际地质模型和预测地质模型的模型残差信息. 波形反演的优点是利用大量振幅相位信息得到高分辨率的反演结果, 其缺点是运行耗时大;当初始模型和实际模型相差较大时,迭代算法容易陷入局部极小点,这是因为目标函数和初始模型同实际模型间的差异是非线性的关系. 逐层波形反演方法是使自上而下每一层的目标函数最小,这样总的目标函数也是最小的. 利用二分法速度扫描确定每一层速度不仅提高了运算速度也避免了迭代算法陷入局部极小点的问题. 结合介质扰动响应和目标函数值变化可以更为准确迅速地确定每一层速度和该层界面位置.     

变形监测网非线性二类动态优化设计中观测权的解算方法

根据变形监测网非线性二类动态优化设计的数学模型,本文从一个简单的网形入手,导出测边网非线性二类动态优化设计数学模型的具体形式,并提出了采用非线性优化设计技术的方法－投影梯度算法解算这种模型,从而将这种解算方法推广到求解任意网形的监测网非线性二类动态优化设计中的观测权。     

激电中梯测量在龙湾套铜矿找矿中的应用

泗水县龙湾套铜矿为岩浆熔离型铜镍硫化物矿床,通过激电中梯测量圈定了若干激电异常,经工程验证,不但在这些异常中发现了9个铜矿体,而且各矿体的形态,规模与异常的形态,规模大致吻合.     

An optimization approach for sustainable development planning of savanna systems

A savanna system is a natural ecosystem in which the competition between grass and woody vegetation in a semi-arid rangeland should be maintained for its sustainable development. Finding an optimal management plan for obtaining maximum economic profit from raising cattle without loss of sustainability of the savanna system during a planning period is a great challenge for rangeland managers. In this study, we formulate the sustainable development planning of the savanna system as an optimal control model, in which maximization of the stocking rate of cattle during the planning period is chosen as the objective while sustainable development requirements are achieved through the constraints represented by the desired final state of the system. Using Pontryagin's maximum principle, the model is transformed into a two-point boundary-value problem with nonlinear differential equations that is then solved using an iterative approach. An example with a specified desired final state in a savanna system without fire is used to demonstrate the performance of the model and the algorithm. Numerical experiments show that the planning strategy obtained from the optimal control model achieves maximum economic profit from raising cattle during the planning period and simultaneously improves the resilience of the system and maintains sustainable development of the rangeland. The outcomes demonstrate that resilience, sustainable development and economic profit are consistent concepts in optimal management strategy for rangeland management.     

珠三角空间梯度葫芦藓的重金属含量及其环境指示意义

以珠三角空间梯度上的核心区广州、近郊区肇庆鼎湖及远郊区怀集三地的葫芦藓为研究对象,对其重金属污染进行研究。结果显示:珠三角地区葫芦藓重金属含量呈明显的梯级分布,其中Cu、Pb、Zn、Cr、Cd含量均表现为广州最高,分别为47.64、68.83、252.87、64.20和1.02mg/kg;肇庆次之,分别为36.34、40.51、143.49、51.29和0.64mg/kg;怀集最低,分别为16.42、11.80、97.13、32.43和0.21mg/kg。珠三角地区葫芦藓内不同重金属的含量差异反映了来源差异,其中Cd、Pb、Zn和Cu之间呈显著正相关关系,反映了重金属元素来自于相同的污染源;而Cr与Cd、Pb、Cu和Zn的相关性相对弱一些,说明Cr的污染源与其他元素存在一些差异,或者说这个元素与其他元素同时污染大气的可能性相对小一些。分析进一步揭示,三地葫芦藓污染同三地大气污染以及工业化进程存在一定的耦合性。基于此,指出葫芦藓可作为研究环境污染的指示标志,具有重要的环境指示意义。     

GOCE卫星重力测量中有色噪声滤波器设计

本文根据卫星重力梯度测量的有色噪声特性,设计了Wiener、AR、FIR三种滤波器,并利用模拟的有色噪声数据对其滤波效果进行了测试,结果表明:对于文中采用的有色噪声数据,AR的滤波效果最好,其次为Wiener滤波器,FIR的滤波效果最差;三种滤波器均可用于GOCE卫星重力测量中有色噪声数据滤波,但其实用性尚需利用实测数据进行检验;可以利用不同的滤波器对含有色噪声的卫星重力梯度数据进行多次滤波,以进一步减弱有色噪声对卫星重力梯度测量精度的影响.     

1900—2010年地磁场水平分量梯度的全球变化

本文根据最新的国际地磁参考场模型(IGRF11),结合梯度法分析能够很好的表现细微变化部分特征的优点,计算和绘制了1900—2010年期间间隔5年的全球地磁场水平分量H的水平梯度和垂直梯度,分析其时空分布,各磁异常中心位置和强度的变化规律。结果表明,地磁场的各个异常中心位置在水平方向和垂直方向上都有变化,主要以西漂为主,南大西洋正磁异常区水平分量梯度异常中心点强度值变化最大。     

A multiscale adjoint method to compute sensitivity coefficients for flow in heterogeneous porous media

A multiscale adjoint (MSADJ) method is developed to compute high-resolution sensitivity coefficients for subsurface flow in large-scale heterogeneous geologic formations. In this method, the original fine-scale problem is partitioned into a set of coupled subgrid problems, such that the global adjoint problem can be efficiently solved on a coarse grid. Then, the coarse-scale sensitivities are interpolated to the local fine grid by reconstructing the local variability of the model parameters with the aid of solving embedded adjoint subproblems. The approach employs the multiscale finite-volume (MSFV) formulation to accurately and efficiently solve the highly detailed flow problem. The MSFV method couples a global coarse-scale solution with local fine-scale reconstruction operators, hence yielding model responses that are quite accurate at both scales. The MSADJ method is equally efficient in computing the gradient of the objective function with respect to model parameters. Several examples demonstrate that the approach is accurate and computationally efficient. The accuracy of our multiscale method for inverse problems is twofold: the sensitivity coefficients computed by this approach are more accurate than the traditional finite-difference-based numerical method for computing derivatives, and the calibrated models after history matching honor the available dynamic data on the fine scale. In other words, the multiscale based adjoint scheme can be used to history match fine-scale models quite effectively.     

海量扫测数据特征点及边界提取方法研究

针对“水声呐”水下扫测设备测量所得的数据量大,精度高,分布规则,但同时数据的冗余度大的特点,为了真实反映水下地形,利用四叉树的数据分块思想对海量数据进行预处理,再对处理后的分块数据采用绝对高程差,高程加权平均等算法判断不同分块窗口的地形的起伏状态,然后用Jenson＆Domingue等算法提取特征点,同时把图像处理边缘提取方法——梯度算子应用到河道扫测边界提取中。