biconcave,concavo-concave

Orthogonal Test for Optimization of Extraction Procedure of Zanthoxylum nitidum(Roxb.)DC.;

正交实验优选两面针的提取工艺

Objective:To screen anticancer extractions of Chinese herbs Zanthoxylum nitidum(Roxb.

目的:对中药两面针、白花丹提取物进行体外抗肿瘤活性筛选并对其抗癌分子机制进行研究。

The dihedral angle between the oblique inserted pipes is calculated with great simplicity.

运用投影变换对两相贯曲面的求交进行降维降阶处理，将空间问题转化为较低阶次的平面问题，可以大大地简化求解斜插管两面角的算法，从而为在此类构件上正确开制焊缝坡口解决了一个难题。

The expressions of dihedral angle and cutting angle of the intersecting groove are deduced by way of space analytical geometry.

利用空间解析几何原理推导了多管、板相贯坡口的两面角和实际切割角的表达式 ,建立了切割多管、板相贯坡口的数学模型 。

A method of right angle auxilliary projection on an arbitrary plane is provided, by which the dihedral angle can be obtained directly.

提供一种在一般位置平面上的直角辅助投射方法，直接求两面角，具有概念明确唯一，作图方法简单，可以适应钣金划线工作中制造卡角样板的实际需要。