二次形式

In the CAD system for progressive dies, the method is introduced to automatically generate geometric models of stampings through inputting the product drawings by AutoCAD and picking-up the entity information from DXF files and programming with ObjectARX and C＋＋ language, at the same time, generating algorithm of close contour lines and unidirectional chain-table structure are used to express the models of stampings, the class and direct judgment of contour lines are realized and the entity existing side is judged by analytical geometry, which efficiently solves the problem of automatic input of drawings of stamping and providing information of process planning and mold design.

在级进模CAD系统中，将产品的图形信息以AutoCAD直接绘图形式输入到计算机中，从AutoCAD的图形交换文件中提取信息，采用面向对象的二次开发工具ObjectARX和C＋＋语言编写接口程序，并通过封闭轮廓的生成算法自动生成冲裁零件的几何模型，且用单向链表的形式加以表达，同时对冲裁零件图形的轮廓进行分类与走向判定，采用简单的解析几何方法对实体存在侧进行判定，有效地实现了零件图形的自动输入，为级进模CAD系统的工艺计算和模具工作部分的设计等提供了必要的信息。

Hilbet-type inequality is important in analysis and its applications. In recent years, by improving the way of weight coefficient, some research on the extensions and applications of this type of inequalities are developed. In this paper, we give a Hilbert infinite series inequality with the best constant factor whose kernel is a negative quadratic form by applying the method of weight coefficients. And an equivalent form is considered.

Hilbert型不等式在分析中有重要作用，近年来，由于改进权系数的方法，发展了这类不等式，并进一步推广应用和研究，应用权系数方法给出的一个带有最佳常数的核为负二次型齐次的Hibert型无穷级数不等式，同时考虑了它的等价形式。

Feature parameters are achieved by comparing the coefficient of standard representation and general representation. As for cone, parameter of general representation has no explicit geometric meaning and can not reflect design intent.

基于二次曲面的统一表示方程，采用最小二乘法进行参数拟合，通过对比其标准形式和二次曲面的统一表示方程，确定圆柱曲面特征带有明显几何意义的参数圆柱轴线法矢量、圆柱的中心和半径。

The parametric representation of segment can be gained from quadratic patch and constrained equations with cubic patches.

利用二次曲面的参数形式，由三次曲面片可得到曲线的隐参数约束形式，从而得到曲线的参数形式。

Then, a regularized quadratic optimization model in the form of homotopy is presented.

其后，在求解的二次规划模型上以同伦形式添上正则项得到同伦形式的正则化模型。

Furthermore,it can represent the elliptic curves,parabola and other quadratic curves without using rational form.

给出了一种基于三角函数的类三次参数曲线，该曲线不仅具有类似于三次Bézier曲线的诸多性质，而且无需有理形式即可精确地表示椭圆、抛物线等二次曲线。

This paper utilizes the Reciprocal Law Two Times to prove that the rational number of a kind of form is not the integer, and proves that the number of another kind of prime is limitless.

摘要利用二次互反定律证明了某类形式的有理数不是整数，并且证明了某类形式的素数的个数是无限的。

This paper utilizes the Reciprocal Law Two Times to prove that the rational number of a kind of form is not the integer ,and proves that the number of another kind of prime is limitless.

利用二次互反定律证明了某类形式的有理数不是整数，并且证明了某类形式的素数的个数是无限的。

In this paper the influence of the core structure , the winding configuration and, especially, the unequal gap lengths among the secondary coil pancakes on the stray field is studied by using the software ANSYS .

利用ANSYS软件计算多种情况下超导变压器的磁场分布，研究了变压器的铁心结构、绕组形式、二次绕组不均匀气隙以及不同的一、二次绕组线圈高度等因素对漏磁场的影响。

The trigonometric polynomial curves retain the main superiority of the quadratic Bézier curves.

给出了二次三角多项式形式的Bézier曲线，基函数由一组带形状参数的二次三角多项式组成。

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。