查询词典 integral curvature

Thus, to study tooth surface curvature is significant. However, from the published information, the curvature of face gear drives hasn′t been well studied until now. Based on the knowledge of differential geometry, a method for calculating principal curvature and principal directions for face gears is established, and thus the principal v...

文中利用微分几何原理推导了面齿轮传动的齿面主曲率与主方向，由此得出面齿轮传动中诱导法曲率的两个主值；开发了相应的程序；进行了实例计算；分析了传动中的主要参数对曲率的影响，所获得的结论对面齿轮传动的强度计算与分析具有参考价值

The approach of solving mean curvature,Gaussian curvature and principal curvatures of general triangular mesh model was derived.Considering coarse triangular mesh model is often seen,in order to increase the precision of curvatures,combined with Loop subdivision algorithm,the curvature algorithm was further extended.

推导了一般三角形网格模型顶点的平均曲率、高斯曲率和主曲率的计算方法，考虑到经常遇到粗糙三角形网格模型，为提高其曲率计算方法的精度，结合Loop细分曲面算法，进一步拓展了该曲率计算方法。

The parameters are :① reservoir effective thickness;② reservoir porosity;③ reservoir volume efficiency;④ fair pay ′ s reservoir volume efficiency;⑤ distance to the fault;⑥ reciprocal of the square root of the distance to the fault ）;⑦ apparent fold strength coefficient;⑧ maximum principal curvature of structural plane;⑨ transversal section line curvature;and ⑩ longitudinal section line curvature.

摘 要 介绍了气井产能的确定方法及地质参数的选择与计算方法：采用初始二项式无阻流量、稳定产量及初始采气指数作为气井产能评价的指标；10项参数分别是①储层有效厚度；②储层孔隙度；③储容系数；④好储层的储容系数；⑤与断层的距离；⑥与断层距离开方的倒数；⑦视褶皱强度系数；⑧构造面最大主曲率；⑨横向剖面线曲率；⑩纵向剖面线曲率。

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

Its amount has relation with acting load. The influence on sectional curvature of bending components is the greatest one, the ultimate curvature of corroding section decrease obviously, and the sectional curvature increases rather sharply with the increase of rust rate during the process of corrosion. The anti-cracking capacity of prestressed bending R. C. components may be damage. For the convenience of engineering usage and damage evaluation of structure, this paper presents a concept of sectional damage coefficient on the foundation of experimental and treatment study.

试验与理论研究均表明，受压区钢筋锈蚀后对普通钢筋混凝土和预应力钢筋混凝土受弯构件的承载力影响均不大，但对构件的正常使用性能有较显著的影响，受压区钢筋锈蚀过程中，截面刚度有较显著的下降，挠度及受压区混凝土压应变随锈蚀量增加而增加，增加值与使用荷载大小有关；受弯构件的截面曲率所受影响最大，锈蚀后截面的极限曲率有明显的下降，在使用荷载作用下，截面曲率则随钢筋锈蚀量的增加而有较显著的增加；而预应力混凝土受弯构件的抗裂度会下降。

According to the discrete curvature on triangle meshes,more important features can be preserved in regions of high curvature after simplification.A method to get the new vertex after the collapse of a triangle based on discrete curvature and spherical surface estimation is also given.

通过三维扫描仪得到的数据构建的三角网格模型，由于其采样密度均匀，因此造成了数据量庞大，受到存储和传输带宽的限制，使得其很难在实际应用中直接使用。

The surface of image can be looked as a curved surface, and we can simulate a conicoid function in local area. Based on this function we can estimate the gradient and the curvature of the curved surface points, and set proper thresholds of gradient and curvature, we can detect the centre lines of roads with correlative process including removing small areas, area growth, thinning, etc. Lastly through seting proper thresholds of the gradient and the curvature again, the original road junctions can be detected and then verified by the road lines detected formerly.

基于微分几何的道路交叉口识别方法：把影像的灰度表面看作是一个曲面，在局部区域内拟合一个二次曲面函数，通过该函数来估算梯度和曲率并设定合适的梯度和曲率阈值来检测道路中心线，并进行相关处理，例如去除小区域、区域增长、细化等，然后再设定合适的梯度和曲率阈值，检测出初始道路交叉口，并用检测出来的道路来进行确认。

Curvature is the result of geometric structure in image; a new third order partial differential equation is proposed which transports curvature information along isophotes. The third order POE is morphologically invariant. Helmholtz vorticity equation which annihilates vorticity and third order POE which forward transports curvature information are coupled to be a new model.

曲率是图像几何特征作用的结果，本文提出沿等照度线方向传输曲率信息的三阶形态学不变偏微分方程，并将抑制涡量的无粘亥姆霍兹方程和正向传输曲率信息的三阶偏微分方程耦合。

The anticlastic curvature caused by bending is 1700 times as long as the sagittal curvature, and the incident angle error is only 2.2 μrad. The Von Mize stress on the bender is about 806 MPa. When Beryllium-Cu is selected as the material of the bender, the linear relationship between the curvature of crystal in 0.57~1.72 m and the driving forces in 8~2.67 N is obtained.

优化后晶体因压弯产生的鞍形曲率半径约为弧矢曲率半径的1700倍，造成的人射角误差为2.2μrad；压弯装置上的最大平均应力约为800MPa，并由此确定了以铍青铜作为压弯机构的材料，晶体的曲率半径为0.57~1.72m和驱动力为8~2.67N时的线性关系。

Its primary coverage includes: Function and limit, derivative and differential, theorem of mean and derivative application, indefinite integral, definite integral and application, space analytic geometry and vector algebra, function of many variables differential method and application, multiple integral and curvilinear integral, infinite series, differential equation and so on.

其主要内容有：函数与极限，导数与微分，中值定理与导数应用，不定积分，定积分及其应用，空间解析几何与矢量代数，多元函数的微分法及其应用，重积分与曲线积分，无穷级数，微分方程等。

But this is impossible, as long as it is engaging in a market economy, there are risks in any operation.

但是，这是不可能的，只要是搞市场经济，是有风险的任何行动。

We're on the same wavelength.

我们是同道中人。