查询词典 parametric curvature

On the basis of OCM, segmentation based on curvature radium is presented in the paper, in which curvature radium is calculated using parametric-surface fitting, and detecting edge points is realized from orthogonal direction, which ensure the integrality of edge points. Since the data is organized by cross-line in OCM, a new arithmetic, Double-direction Angle Difference arithmetic, is brought forward, which can pick up edge points more quickly.

物体的表面一般由多个曲面相交组成，要建立完整的几何模型，需要对测量数据进行区域分割——区分不同曲面的数据，现有的区域分割大多是对单视图的图像式测量数据进行的，但完整的CAD模型需要联合多个视图产生，本文在上面提出的三维正交模型的基础上，提出了三种区域分割方法：第一种方法是基于曲率半径的数据分区方法，通过二次参数曲面拟合计算局部曲率半径，从正交的多个方向进行检测，保证了边点提取的完整性。

Based on this property, by solving a series ODEs we construct a two-parametric family of helicoidal surfaces under cubic screw motion with prescribed mean curvature or Gauss curvature and solve an open problem left by Beneki.

基于这一点，当螺旋面的平均曲率或Gauss曲率为给定光滑函数时，本文选取伪正交标架，使得两类螺旋面的平均曲率和Gauss曲率的表达式相对简化，通过求解一系列的非线性常微分方程，即可确定一族生成曲线，从而最终确定平均血率或Gauss曲率为给定光滑函数的双参数族螺旋面，并在这一过程中解决了Beneki等人留下的一个公开问题。

Applying this rule, we give a kind of definition of discrete Gauss curvature and mean curvature on the discrete parametric curves net.

应用这种加细方法，我们给出了一种针对由离散参数曲线网形成的四边形网格上任意顶点处的离散估计值的定义方法。

The error compensation is introduced in the interpolation algorithm to increase the interpolation point's solution precision in the cutting direction of the parametric curved surface. The reasonable simplification of the computed result of the interpolation point's parameter value is carried in the operation process by focusing on the character that curvature of slow-varying parametric curved surface changed slowly and the feature that the scanned profile of translational scanned curved surface is parallel along the scanned line.

通过引入误差补偿值以提高参数曲面在走刀方向上插补点的计算精度，针对缓变参数曲面曲率缓变和平移扫描曲面扫描轮廓沿扫描线平行的特点在运算过程中对插补点参数值的计算结果进行合理简化。

This article that focuses on the systematic and in-depth research in the current primal problem about abnormal burst pressure reservoir depress burst pressure has procured following main fruits:1 It forms the method which could obtain massive vertical static state mechanics parameters.2 In a foundation of acquisition of rock mechanics parameters,apply bent lamella that as mechanical model along with characteristic of actual geologic characteristics to analysis curvature for anticlinal strcture, get homologous tectonic stress value throug relation between the curvature and stress and different principal curvature in anticlinal structure,consequently set up laminational stress model for anticline reservoir. The block lamination for existed fracturing date has formed method of setting up mechanical model of lamination terrestrial stress by abtaining the block tectonic stress coefficients which are got by complex utilization test, laboratory test and fracturing date playback.3 Analysesing the main reason which lead to high burst pressure by considering the characteristic of reservoir geology,reservoir,and rock mechanics and reservoir damage,etc.Establishing burst pressure quantitative prediction model which provide gist for depressing construction risk and optimizing construction craft under the condition of open hole completion ,gun-perforated completion and damaged reservoir.4 Provding theoretical basis for interpreting acidification pretreatment which could depress busrt pressure by finding the relation between the influencing factors and rock machanics parameters and analysing the factors that have effect on rock mechanics parameters. Expounding the mechanism of reaction of mixed monomineral and acid from the angle of microcosmic element, evaluating quantitatively acid sensilility of different kinds of mineral effectively, and determing the first-order reaction dynamical equation of each mineral.5 Revealing rock mechanics property chage as a result of acid flooding in different condition by sandstone traumata experiment in different temperatures which combined with rock mechanics triaxial stress experiment.6 Associating damage mechanics with sandstone acidizing, established sandstone damage mechanics model in the foundation of the recognition on the rock mechanics parametric variation which is caused by acid-rock reaction in both macroscopic view and microscopic view ,also demonstrated those processes and quantitative estimated the acid busrt pressure to direct the site operation.

本文针对目前异常破裂压力储层降低破裂压力的主要问题展开较为系统和深入的研究，取得了以下主要成果：1形成了利用测井资料，结合室内岩芯测试结果，获取静动岩石力学参数的相关性特征，从而获得纵向上大量静态力学参数的方法。2在获取了岩石力学参数的此基础上，利用弯曲薄板作为力学模型，结合区块实际地质特征对背斜构造进行曲率分析，通过曲率与应力的关系，利用背斜构造不同部位的主曲率求得相应的构造应力值，从而建立起背斜储层的分层应力模型；对已有压裂资料的区块分层，形成了综合利用测试、室内实验、压裂资料反演获得该区块构造应力系数，建立起分层地应力的力学模型的方法。3综合考虑储层地质、油藏、岩石力学特性和储层伤害等因素，分析造成高破裂压力的主要原因，综合利用岩石力学、弹性力学等知识，建立了裸眼完井、射孔完井条件下以及储层受到伤害后的储层破裂压力定量预测模型，为降低施工风险和优化施工工艺提供了依据。4完成了物性、岩性影响岩石力学参数的因素分析，找出了各影响因素和岩石力学参数之间的关系，为从机理上解释酸化预处理降低破裂压力提供了理论基础；从微观元素的角度阐述了单矿物与酸反应的机理；并在此基础上，有效评价了各种矿物的酸敏感性，定量确定了岩石中各矿物的一级反应动力学方程。5完成了不同温度下的酸液类型、酸液浓度、注酸量等一系列砂岩损伤实验，结合岩石力学三轴应力实验，系统揭示了在不同条件下注酸而引起的岩石力学性质变化。6将损伤力学与砂岩酸化相结合，在宏观、微观两个方面认识酸岩反应引起岩石力学参数变化基础上，建立了砂岩损伤力学模型，并对其进行验证，在此基础上定量计算酸化后的破裂压力，有效指导现场施工

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。