切线

Well, he conceives God in the creation of the world like a mathematician who is solving a minimum problem, or rather, in our modern phraseology, a problem in the calculus of variations .

众所周知，通过发现切线方法，函数的最大与最小值理论取得了最大进展，这归功于莱布尼茨。他认为上帝在创世中就像一个解决最小值问题--或者用我们当代的术语说，变分法问题--的数学家。

Construct an animation displaying a pair of orthogonal tangents of a fixed cardioid.

建构一动态绘图。展示给定的心脏线外一对的正交切线。

After the analyses of the force about different shape of caterpillar thorn, it was considered that the drive force of caterpillar tractor consisted of friction force, extruding and cutting force, edge cutting force and thorn friction force.

一般认为，拖拉机在田间行驶时，切线牵弓l力是由土壤抗剪力产生的，其计算公式通过土壤剪切力导出11·2}。这一观点忽略了其它一些因素的影响，并且只适用于直板式履刺。

The paper deals with curvature line and curvature characteristic of developable surface based on differential invariant of developable surface and it details curvature line and curvature characteristic of cone and tangent surface .

本文通过可展曲面的微分不变量，导出可展面的曲率线与曲率特征，并以锥面和切线曲面为例阐明这些特性的几何意义。

According to the inner or outer tolerance the algorithms for maximizing the forward-step by maintaining a constant tolerance are provided by the chord line or tangent line respectively.

建立了复杂曲面球头铣刀三坐标数控加工刀位计算模型，根据正负允差的不同要求，分别给出了弦线法和切线法自适应步长的刀位点生成算法。

There are many methods to measure the circular curved line in circuitry construction survey.

在线路施工测量中，圆曲线测设方法有很多，通常采用偏角法或切线支距法。

Methods: 1. Experimental laparoscopic liver resection: We selected pigs as experimental models aiming to approach human beings physiological and anatomical condition. After CO2 pneumoperitoneum was established, the ligaments around liver were dissociated. Livers were cut off by the methods such as clamp dissection, microwave tissue coagulator, ultrasound dissector, Ligsure dissection, hand-assisted, short abdominal incision laparoscopy-assisted, and Endo-GIA switcher. The operation time and bleeding volume were compared between different methods of laparoscopic liver resection. The advantages and limitations of different methods were summarized. 2. Clinical laparoscopic liver resection: 15 cases with tumors in segment V of anterior right lobe or segments II, III of left lateral lobe or segment IV of left internal lobe were selected in this study. The liver diseases included hepatocellular cancer, hepatic cavernous hemangioma and hepatic focal nodular hyperplasia. The ligaments around liver were dissociated after CO2 pneumoperitoneum established. Laparoscopic liver resection were carried out by some of the methods combined such as clamp dissection, microwave tissue coagulator, hand-assisted, short abdominal incision laparoscopy-assisted, ultrasound dissector, rotation and suction dissector.

1、实验性腹腔镜肝切除：以猪为实验动物，旨在接近人体的生理、解剖环境下进行实验，建立操作空间后游离肝脏周围韧带，采用钳夹分离切肝法、微波刀切肝法、超声刀切肝法、Ligsure切肝法、手辅助腹腔镜肝切除法、小切口腹腔镜辅助切肝法、Endo-GIA切肝法等方法实施腹腔镜下肝切除，比较不同切肝方法的手术时间、出血量，总结各种方法的优越性及其局限性。2、临床腹腔镜肝切除：选择肿瘤位于肝右前叶第Ⅴ段、肝左外叶第Ⅱ、Ⅲ段及左内叶第Ⅳ段的15例患者，病种包括原发性肝癌、肝海绵状血管瘤、肝脏局灶性增生，建立气腹后游离肝脏周围韧带，采用钳夹分离断肝、微波刀固化后断肝、手辅助腹腔镜肝切除、小切口腹腔镜辅助肝切除、超声刀断肝、旋吸断肝等多种方法分离切线肝组织，暴露管道结构，再采用高频电凝、钛夹夹闭、缝扎止血、止血纱布覆盖、氩气刀止血、生物胶止血、Endo-GIA处理等多种方法相结合处理肝断面，统计手术完成情况、手术时间、手术出血量、术后并发症及术后住院时间等，评价腹腔镜肝切除的可行性及安全性。

2At drive than will certainly,driven gear, while having the more same sizes, hyperboloid have diameter not larger of gear wheel not initiative than corresponding spiral awl gear wheel, intensity and bigger initiative gear wheel axle and bearing rigidity of higher teeth of a cogwheel.

螺旋角是指在锥齿轮节锥表面展开图上的齿线任意一点A的切线TT与该点和节锥顶点连线之间的夹角。在齿面宽中点处的螺旋角称为中点螺旋角(图5—4)。通常不特殊说明，则螺旋角系指中点螺旋角。双曲面齿轮传动比为

The methods of development for cones and tangent surface on C-Bézier curve and the complex surfaces are obtained.

首先，构造了C-B？zier曲线上的锥面和切线曲面，分别建立了它们到平面的等距映射，给出了C-B？

The graph of a concave function is always below its tangent.

一个凹函数的图象总在它的切线的下方。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。