查询词典 potential gradient

Firstly, the approach formulates a cost functional to turn the inverse problem into a constrained minimization problem according to least squares criterion, then the resulting constrained minimization problem is transformed into an unconstrained minimization problem by using a penalty function technique, and then the closed Fr chet derivatives of the Lagrange function with respect to the properties are derived based on the calculus of variations, finally, one can solve the resulting problem by using any gradient-based algorithm and the finite-difference time-domain method.

该方法首先以最小二乘准则构造目标函数，将逆问题表示为约束最小化问题；接着应用罚函数法转化为无约束最小化问题；然后基于变分计算导出闭式的拉格朗日函数关于特征参数的Fr chet导数；最后借助梯度算法和时域有限差分法迭代反演德拜模型参数。

Now what we finally came up with is that it is still the most robust and the best way to evaluate valvular stenosis by reporting a composite of peak transvalvular velocity, mean gradient and continuity equation valve area.

我们最终得到的结果是，跨瓣峰流速、平均梯度和瓣膜面积的复合指标仍然是最稳定和有效的评价瓣膜狭窄的方法。

Two gradient-based optimization schemes were investigated for continuous wave near infrared optical tomography.

研究了两种基于梯度的优化算法用于连续波近红外光断层成像的情况。

To read the contour map, people must understand the relationship between the terrain and the contour map, including the change of gradient and depth of space.

而阅读等高线图首重要先了解地形与等高线图的关系，其中包含坡形的变化及空间深度变化。

In order to improve the accurate of measurement, the artifacts, such as eddy current, thermal convection, background gradient must be considered both experimentally and methodologically.

我们把多自旋回波和双向梯度场技术相结合，用来抑制这些干扰，并在生物样品的自扩散系数测定中的进行了应用。

It leads to significantly lowered and expanded profiles for the Reynolds correlations, and a larger temperature gradient in the central part of the super-adiabatic convection region but a small one near the boundaries of the convection zone.

研究发现，如果适当选取自由参数的值，则不论是采用局地还是非局地Reynolds应力模型的太阳模型都可以得到比标准太阳模型更符合观测结果的理论振动频率。

The results show that the increasing Marangoni number will lead to more nonlinear distribution of temperature field, but streamfunction of the cell center; vorticity on the wall and peak value of velocity diminish first, then increase, finally lose stability. The thermocapillary convection in the whole liquid zone appears to get stronger along with the augmentation of Prantal number. The effect of increasing of Biot number on temperature and flow fields is not obvious although the convection is strengthened a little. As increasing the aspect ratio A, thermocapillary convection induced by temperature gradient and liquid viscosity becomes stronger.

结果表明：温度场的非线性分布随着Ma数的增大而加剧，但对流涡胞中心流函数、壁面涡量和轴向、径向速度峰值并不象温度场随着Ma数的增大而单调增大，而是先减小，然后增大，最后失稳，表明Ma数对热毛细对流的影响比较复杂，针对不同的物理模型，会导致完全不同的流态；Pr数愈大，流体的热扩散能力在粘性扩散与热扩散能力之比中愈占支配地位，当Ma数一定时，热毛细对流随Pr数的增大在整个液体区域内有增强的趋势；Bi数增大，热毛细对流有所增强，但不甚明显；A的增大使得由温度梯度和流体粘性诱导的热毛细对流随之增强。

In accordance with discrete, non-symmetry and time-delay feedback neural networks, we provide some theoretical criteria to judge the stability for designing the networks. On continuous feedback networks, we built an algorithm to estimate the convergence region. On the HNN feedback networks, an effective optimization algorithm based on the annealing strategy and the chaotic neural network is presented, and some disciplinary conclusions are provided to guide the selection of parameters. Simulation results on benchmark problems demonstrate that the performances of our algorithm are distinctly superior to those of the classic HNN based on gradient descend and stochastic optimization methods based on probabilistic distribution.

针对离散、非对称和时延等三种类型的动态反馈网络，给出了可用于网络设计的稳定性判别准则；针对连续动态反馈网络，建立了其收敛域估计的一个算法；针对以HNN模型描述的动态反馈网络，基于退火策略和混沌神经网络提出了一种高效的优化算法，建立了可用于指导参数选择的一些规律性结论，对典型算例的仿真研究显示，改进算法在各类性能上相对基于梯度下降的传统HNN模型和基于概率分布的随机优化算法，具有明显的优越性。

All the following process was done on the sub image. Second, the morphology gradient theorem and its converse theorem were both proved. And the DGT reverse theorem was used to look for the regional maxima points of the sub image. In the improved region growing method, the seeds were those regional maxima points.

然后证明了数学形态学的膨胀梯度定理(dilation gradient theorem， DGT)及其逆定理，并利用DGT逆定理查找图像的局部极大值点，将灰度值不为0的局部极大值点作为区域生长法的种子点。

Keywords Closed convex cone;gradient projection method;Least-squares solution;Inverse matrix problem;Inverse eigenvalue problem;Matrix completion problem;Optimal approximation

Article From 湖南大学；应用数学博士论文 2005年度闭凸锥；投影梯度法；最小二乘解；矩阵反问题；矩阵逆特征值问题；矩阵完全化；最佳逼近

My father is over 60 years old, and he lifts weights every day.

我爸爸六十多岁了，他每天都练习举重。

Then in a serious tone she declared:"It doesn't pay, dear boy, to look like a ninny with one's wife the first night."

两眼湿润了，她把身子蜷得很小，这样似乎可以更好地闻闻自己。