查询词典 gradient

It has been found that, the matrix hardnesses is reduced by about 30 % with the increase of parameter P, and there exists a hardness gradient in phase α from grain center to grain boundary, which is in correspondence with the concentration gradient of alloy elements.

多年来的研究业已发现珠光体耐热钢在高温下长期运行中会发生珠光体球化、碳化物聚集、合金元素在固溶体和碳化物之间重新分配等组织变化[1]。

FR conjugate gradient methods with perturbations are proposed. The global convergence property of the first method is proved under the condition of main directions' sufficient descent. Whereas, in the proof of the convergence for the other two methods, we only need main directions' descent. Importantly and quite interesting, boundedness conditions such as objective function being bounded below, boundedness of level set are not needed. Chapter 5 presents a version of Dai-Yuan conjugate gradient method with perturbations.

在主方向充分下降的条件下证明了第一个方法的全局收敛性，而后两个方法的收敛性是在主方向下降的条件下证明的，这些收敛性证明的一个共同特征就是不需要目标函数有下界或水平集有界等有界性条件，第5章采用Wolfe或Armijo步长规则提出了带扰动项的Dai-Yuanabbr。

Researches show that the drive force characteristics of the electric tractor drive system based on series DC motor is close the ideal characteristics, the curves are concave, low speed with constant power, and high speed with constant torque; the electric tractor has large working speed under different shifts, but the extensive coincidence speed shows that the variable ratio of the gear is unreasonable; the maximum climbable gradient of this electric tractor is more than 30%, and does not need frequent shift when working for its extensive climbable gradient; there are many influence factors of continuous working time, which the more obvious factors are working speed and working load, the working time increases with the increase of the working speed and working load.2. Simulation researches on the drive characteristic of the electric tractor.

研究结果表明：基于串励直流电动机(来源：ABC21论文网www.abclunwen.com)的电动拖拉机电驱动系统的驱动力特性场接近理想驱动力特性场，其各挡下的驱动力特性是一组下凹的曲线，低速恒转矩，高速恒功率；同一行驶速度下所对应高挡驱动力大于低挡驱动力，这是由电机的调速特性决定的；电动拖拉机各个挡位下具有较广的稳定作业速度范围，但是各个挡位之间速度重合的范围较多，说明所用变速箱变速比与电动机匹配不合理；电动拖拉机最大爬坡度达到30%以上，并且各挡爬坡度变化范围较广，作业过程中不需要频繁换挡；影响电动拖拉机连续作业时间的因素较多，其中作业行驶速度和作业负荷影响最为明显，作业负荷越大，连续作业时间就越短，作业速度越快，连续作业时间就越短。2、电动拖拉机驱动特性仿真研究。

We have studied a model of a non-Newtonian viscous compressible fluid in 3D bounded domains, in which the viscous part of the stress tensor satisfies the coerciveness condition and the values of the growth condition ., are positive constants. Here is the tensor of the velocity gradient, is the strain tensor and ,which depends on the tensor of the velocity gradient, is the hefts of .

对满足强制性条件，以及增长性条件的非牛顿粘性可压缩流体在三维有界区域中的流动进行了研究，其中和为正常数，为速度梯度张量，是偏应力张量，为的分量，它依赖于速度梯度张量。

It has been deduced that the search direction remains the same but that the step length decreases in optimizing the improved cost function with the conjugate gradient algorithm from the gradient of the cost function that the FIR filter apporaches the contrary point spread function more, and that the estimated image is closer to the original one.

从代价函数的梯度入手推导出共轭梯度算法，其搜索方向保持不变而搜索步长变小，使滤波系数更加逼近于点扩展函数逆算子，从而使估计图像与原始图像更加接近。

Chapter 1 is the introduction, which introduces conjugate gradient method, gradient-related memory method and the main results obtained in t...

第一章是本文的绪论部分，简要介绍了记忆梯度方法和共轭梯度方法的发展现状以及本文的主要工作。

Meanwhile the biconjugate gradient method instead of the conjugate gradient method is used to accelerate the iteration process.

同时用双共轭梯度法代替共轭梯度法来加速迭代过程。

The simulation floating zone modelwith zero temperature gradient in the middle of the hot rod is proposed to simulate thehalf part of the full floating zone convection,since the temperature gradient in the middleof a full floating zone approaches zero.

根据加热方式的不同，可以将半浮区液桥分为通常半浮区液桥模型、模拟半浮区模型以及改型半浮区模型。通常半浮区液桥模型，液桥热端材料一般选择为金属材料，使得热端温度分布均匀。液桥产生热毛细对流时，在液桥热端内侧存在较大的轴向温度梯度。而在全浮区热毛细对流中，浮区中间的轴向温度梯度在对称条件下应该接近于零。

In order to mine the structure difference of the chinese and english characters,the gradient information of the pixel based horizontal and vertical stroke vector,gradient orientation correlogram and the relative gray information of the location correlation pixels based census transform histogram are used,they can be robust to illumination,noise and resolution and so on,and can be applied to camera-based images.

为了能够很好地挖掘中英文字符之间的结构差异，提出采用基于象素梯度信息的水平垂直笔画向量和梯度方向相关图，以及基于位置相关象素的相对灰度信息的Census变换直方图，它们对光照、噪声以及分辨率等都具有良好的鲁棒性，可以应用于基于相机的图像。

The definitions of generalized directional derivative and generalized gradient of Lipschitz functions defined on Riemannian manifold are presented. Some properties of the directional derivative and gradient are proved by using tangent and cotangent mapping. The minimization necessary condition of nonsmooth Lipschitz functions is given. Moreover, Fritz John necessary optimality condition in mathematical programming is provided on Riemannian manifold.

在黎曼流形上给出了Lipschitz函数的广义方向导数和广义梯度的概念，利用黎曼流形局部上与欧氏空间开集微分同胚的性质以及切映射和余切映射导出了广义梯度的性质和运算法则，证明了定义在黎曼流形上的函数取得极小值的必要条件是广义梯度包含零元素，并利用这些性质给出了黎曼流形上数学规划问题的Fritz John型最优性条件。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。