截面线

In order to assurance the maching accuracy and surface quality of steam turbine blades,based on typical CAD/CAM software Pro/Engineer 2.0,the flow diagram of parametric modeling and maching of turbine blades is drawn;The 3-D entity model of Steam Turbine Blade is upbuilt by parametric modeling method,and the fit-method with NURBS is extracted to smooth the curve surface,and the matrix expression of NURBS is deduced to make the surface more accurate;Then based on it's CAD model,the maching technology process...

为保证汽轮机叶片的加工精度和表面质量，以典型的CAD/CAM软件Pro /Engineer Widefire2.0中文版为基础，绘制了汽轮机叶片参数化设计加工的流程图；用参数化建模方法建立了叶片的三维实体模型，提出用NURBS曲线拟合方法进行光顺处理，并推导出NURBS的矩阵表达式便于截面型线的拟合，进而使叶片的造型更加精确；在CAD模型的基础上，分析了叶片的加工工艺流程，并用软件的CAM功能对叶片进行数控加工仿真，生成了NC代码。

Where : S conductive wire nominal cross section; T short time.

2式中：S为导电线芯标称截面；t为短路时间。

Sup2; LSD new type crimping tools adpots the best lever principle to effectively design the handle,although its structre is short and compact, the operation is very laborsaving when crimping wire of larger cross section

sup2； LSD 新型压线钳，采用最佳杠杆原理对手柄进行有效的设计，虽然结构非常短小紧凑，但操作时，尤其在压接较大横向联合截面的导线时，非常省力。

Presenting the calculating method of the space displacement model of skewed box girder, whit main ideas of: dispersing the skewed box girder into some skewed beam segments and further dividing those segments into some plate pieces according to their forms; describing the displacement functions in the plane of plate piece by assuming that the space displacements of any point in the joint line between the plate pieces are described by using Hermite interpolation functions and that two displacements in the plane of plate piece are linear in the cross direction; Using Hermite interpolation functions to describe the bending the displacement of the unit length transverse frame cutting longitudinal from the skew box girder segment; Finally, describing the space displacements of a point in the plate pieces by two displacements in the plane of the plate and one bending displacement of plate.

提出了斜交箱形梁空间位移场的计算方法：将斜交箱形梁沿纵向离散为若干斜梁段单元，依据箱梁的构成进一步将斜梁段划分为若干板段子单元；各板段联结线上任意点的位移按Hermite函数插值，假定各板段的面内位移沿其宽度方向线性变化，以描述各板段面内位移；沿斜交箱梁段的纵向截取单位长度横截面框架，框架各杆件空间位移按Hermite函数插值，以描述各板段面外位移；板段内任意点的空间位移最终以2个面内位移和1个面外位移描述。

In this paper an innovative method for machining sculptured surfaces is presented. By using a disc cutter with a concave end instead of traditional ball-ended or drum-shaped tools, and adjusting the cut- ted axis to swing relative to the component being machined under some special rules, the envelope formed by the trace of the tool-nose may have the same derivative up to the third order as the required theoretical surface.

本文提出了一种加工自由曲面的新方法，即采用中凹的盘形铣刀取代传统的球头或鼓形铣刀，在每一行程中让刀具轴线相对于工件按特定的规律摆动，使得在垂直于进给方向的法截面中，由刀尖轨迹形成的包络面与理论曲面的法截线具有相同的1～3阶导数，从而在保持精度不变的前提下，使实际行程次数得以大幅度的减少。

By means of using a disc cutter with a concave end instead of traditional ball-ended or flat-ended ones,and adjusting the cutter axis to move relatively to the component being machined according to some special rules,the envelop formed by the trace of the tool-nose in each pass and the required surface have the same derivatives up to the second order in the plane normal to the feeding direction.

采用二阶密切曲率法，即采用中凹的盘形铣刀取代传统的球头或鼓形铣刀，在每一行程中让刀具轴线相对于工件按特定的规律摆动，使得在垂直于进给方向的法截面中，由刀尖轨迹形成的包络面与理论曲面的法截线具有相同的1阶？

Connect the earthing conductor coming from the ground electrode - preferably via a metering point with the green-yellow wire (not less than 16 mm2 )- to the main earthing bar of the switchgear.

框架主接地排与配电室主接地系统用截面不小于16mm2的黄绿线连接，对10台以上的长排列的开关柜，连接节点不少于两个。

Orientation method for the determination of grain boundary character distribution, single section trace method for the analysis of low??index grain boundary plane and five parameter method for the measurement of grain boundary plane character distribution are discussed significantly.

重点讨论了基于EBSD技术的晶界特征分布测定取向差法、低指数晶界面测定单一截面迹线法和晶界面特征分布测定五参数法。

Knitting yarns have less twist than weaving yarns. Thread, used for sewing, is a tightly twisted ply yarn.

缝纫用线是具有圆截面的紧密加捻的合股线。

Knitting yarns have less twist than weaving yarns. Thread, used for sew ing, is a tightly twisted ply yarn.

缝纫用线是具有圆截面的紧密加捻的合股线。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。