方向

The characteristic approximation is used to handle the convection part along the direc-tion of fluid namely characteristic direction to ensure the high stability of the method in approximating the sharp fronts and reduce the numerical diffusion; The mixed finite element spatial approximation is employed to deal with diffusion part and approximate the scalar unknown and the adjoint vector function optimally and simultaneously; In order to preserve the integral conservation of the method, we introduce the modified characteristic method.

该方法对方程的对流部分沿流体流动的方向即特征方向离散以保证格式在流动的锋线前沿逼近的高稳定性，消除数值弥散现象；对方程的扩散部分采用最低次混合有限元方法离散、同时以高精度逼近未知函数及未知函数的梯度；为保证方法的整体守恒性，在格式中引入修正项。

In light of the bascic situation of children s pictures in our country---unitary expression,adultness and for-mulism,this paper points out the future orientation and aim for fine art aducation---renew the idea,reform the teaching methods and encourage creativity.

本文针对我国儿童画的基本现状———表现手法单一、成人化、公式化、提出了今后美术教育需要改进的方向和目标———更新观念，改革教法，鼓励创造，使儿童美术教育向着健康的方向发展。

This paper discusses the theory method calculating surface temperature of ballistic target above aerosphere, and analyses the effect of dimensional orientation of target s flight gesture and sun radiation direction on its surface temperature.

论述了大气层外弹道式目标表面温度的计算方法，对某弹道式目标大气层外飞行过程中当太阳辐射方向改变时其表面温度的变化情况进行了数值计算，分析了目标飞行姿态与太阳辐射方向之间空间方位关系的变化对目标表面温度的影响。

First, binary texture matrixes of horizontal and vertical direction were constructed in the template and target image, and then the prime matching result of the two directions was calculated according to the Alogical XOR logical operation in bytes and the final target correlation credibility was obtained by proportion sum at last.

在模板与目标图像中分别提取水平、垂直方向上的二值化纹理特征矩阵，然后根据字节同或逻辑运算分别计算两个方向上的最佳匹配值，最后，通过加权求和得到最终的目标相关置信度。

The flowing of current first in one direction and then in another makes an alternating current.

电流先向一个方向流动，然后又向另一个方向流动构成交流电。

These numerical tests show that the inex-act self-adaptive alternating direction method and the new alternating direction methodare e?

最后，我们对非精确自适应交替方向法和新交替方向法给出了数值实验结果，证实了算法的有效性。

The subdomain precise integration with multiple inner points can improve the precision. This paper gives alternating direction precise integration method for twodimensional diffusion equation, and discusses the parallel algorithm of this method.

给出了交替方向的二维扩散方程的精细积分算法，将一个时间步积分分为两个方向，使大规模矩阵的计算转化为一些小矩阵的计算，减小了每一步求解的计算量。

Based on wave propagation feature, this paper analyses 3D seismic migration algorithms such as alternating direction implicit method, LU decomposition method, and inverse operator approach method. The result shows that the alternating direction implicit method is fast but causes distortion in wave field extrapolation and affects image accuracy; however LU decomposition and inverse operator approach methods are fast while holding circular symmetry of wave field, and are promising in oilfield exploration and development.

在波的传播特征分析基础上，对交替方向隐式法、LU分解法、逆算子逼近法等三维地震偏移算法进行了分析研究，结果表明，交替方向隐式法虽然快捷但是在波场外推中明显产生畸变并影响成像的准确性，而LU分解和逆算子逼近法是保持波场圆对称特征前提下的快速算法，在油田勘探开发中具有较好的应用前景。

The numerical ex-periment has shown that the number of iterations depends significantly on the positiveparameterα,β. But, in general, it is di?cult to choose a proper parameterα,β. Thuswe propose new self-adaptive alternating direction method which adjusts the scale pa-rameter automatically per iteration based on the message of the iterates. We have provedthe convergence of the method under mild assumptions.Finally, we present some numerical results.

对于我们提出的新交替方向法，数值实验表明，迭代的步数与时间与所取的参数α，β有关，然而我们很难去选择一个合适的参数α，β，因此我们提出新自适应交替方向法，对其中的参数α，β进行自适应调整，这种自适应算法根据每步迭代信息自动地调整参数α，β，并证明了算法的收敛性。

An alternating voltage between two points A and B,determined along a specified path 1,periodically changes sign,so that if it is assumed to be positive in the direction from A to B,it will be negative in the direction from B to A at the same instant of time.

两点之间的交流电压A和B，沿着指定的路径1中确定的，定期的变化迹象，所以，如果它被假定为积极的从A到B，这将是在消极的方向从B到A的方向在time。

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。