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排序方式: 共有344条查询结果,搜索用时 15 毫秒
1.
深部岩盐矿地应力的确定及特征分析 总被引:1,自引:1,他引:1
针对深部岩盐矿溶腔稳定性分析及地应力场分析的要求和深部岩盐矿钻孔水溶开采的条件,结合长山岩盐矿深部地应力研究的实际情况,确定了矿区地应力测试方法、地应力测点和试样选择的一些要求:按照声发射Kaiser效应测地应力的基本原理,提出了沉积岩层非定向钻孔岩芯坐标方向建立的方法和多方向取样及地应力椭球回归分析的声发射Kaiser效应地应力测试方法。该方法根据三维空间多方向试样的Kaiser效应实验结果,采用多元非线性拟合方法确定测点地应力椭球的一般方法,再由二次正交变换确定测点地应力椭球的标准方程,以求得地应力的大小和方向。此方法能避免实验误差的较大影响。长山岩盐矿实验矿井深部地应力测试结果及分析表明,长山岩盐矿深部存在水平构造应力,最大主应力方向在离地表800m深左右由水平方向转为垂直方向;距离地表1000m左右深的岩盐层中,最大主应力一般为30MPa左右。 相似文献
2.
This paper presents an adjustable robust security constrained economic dispatch (SCED) model with wind power uncertainties. First, the scenario based adjustable robust SCED model is presented. It considers multiple scenarios from historical data as well as the spatial correlation among wind farms. Then, the proposed SCED model becomes an optimization problem with a large amount of constraints which is skillfully solved using a lift-and-project minimum volume enclosing ellipsoid (MVEE) based convex hull. Furthermore, the proposed model is transformed into a second order cone programming (SOCP) model by the use of participation factors to generate adjustable generation outputs and thus guarantee the energy balance. In order to further reduce the computational complexity, the inactive constraints reduction strategy is proposed to quickly eliminate inactive SOC security constraints before solving the model. Numerical results of IEEE 14-bus and 118-bus test systems as well as the practical Polish power systems with several wind farms show that the proposed model can achieve better economies. Moreover, more than 82% of security constraints are identified as inactive in various cases of the simulation, and the proposed inactive constraints reduction strategy is promising for improving the computational performance. 相似文献
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Set-membership filtering for systems with sensor saturation 总被引:2,自引:0,他引:2
This paper addresses the set-membership filtering problem for a class of discrete time-varying systems with sensor saturation in the presence of unknown-but-bounded process and measurement noises. A sufficient condition for the existence of set-membership filter is derived. A convex optimisation method is proposed to determine a state estimation ellipsoid that is a set of states compatible with sensor saturation and unknown-but-bounded process and measurement noises. A recursive algorithm is developed for computing the ellipsoid that guarantees to contain the true state by solving a time-varying linear matrix inequality. Simulation results are provided to demonstrate the effectiveness of the proposed method. 相似文献
7.
ABSTRACT A numerical solution of the diffusion equation to describe solute transport inside ellipsoids, assuming a constant difiusion coefficient and a corrective boundary condition, is presented. The difiusion equation in a prolate spheroidal coordinate system was used for a hidimensional case. The finite volume method was employed to discretize the basic equation, utilizing a uniform grid size. The equation was solved irteratively using the Gauss-Seidel method. The effect of Biot number and the aspect ratio of the body on diffusion rate and concentration during the process is presented. Plots are presented for Biot numbers from 0.05 to infinity and aspect ratios of 1.1, 2.0 and 5.0. To investigate the effect of the aspect ratio, different results changing the aspect ratio for Bi= 1.0 are shown. The results show that the model is consistent and it may be used to solve other cases such as those that include cylinder and sphere geometry, and/ or those with variable diffusion coefficients with small modifications. 相似文献
8.
单层椭球面网壳的参数化设计 总被引:1,自引:1,他引:0
根据椭球面网壳的特点,采用通用有限元软件ANSYS的APDL参数化语言,研制了两种类型的单层椭球面网壳,并实现了在给定几何参数:纵向跨度S1、横向跨度S2、矢高F、环向对称区域份数Kn、径向节点圈数Nx下,即可确定单层椭球面网壳的形式.通过设计实例表明,该参数化设计方式简单、高效、实用,为采用ANSYS软件对椭球面网壳的不同类型的设计及分析奠定了良好的基础. 相似文献
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通过井眼位置进行监测,对轨道偏移进行提前预测,能够很好地对井眼轨道控制提供判断依据.综合考虑导致轨道偏移的系统、仪器等各方面因素,对误差椭球三个半轴的计算进行研究,加入绕主法线旋转角度,使得误差椭圆角度更准确.利用OpenGL技术,实现了误差椭球的三维可视化,从而能够直观地看出误差的大小以及下一步发展方向,为井眼轨道控制以及井眼防碰提供参考. 相似文献
10.
详细介绍了天津市通过对二等三角网进行改造(即进行联合平差)获得了天津市二等三角网点高精度的地心坐标的数据处理方法,并对数据处理结果进行了分析与检验. 相似文献