平面

The special geometric restrictions like parallelism andperpendicularity implicated in vanishing elements are deeply studied. In single-view case,the theory is presented to interpret relationship between two planar lines by applying 3Dinvariants of vanishing points. In two-view case, the method on extraction vanishing pointof an arbitrary spatial line is described, and moreover, the theory is presented to interpretrelationship between two elements in 3D space, such as two lines, two planes, line andplane, and so on.

4详细论述了消失元素(消失点、消失直线、消失平面等)所体现的垂直、平行等特殊几何约束关系；对单视图，提出了一种利用消失点列的3D不变量解释平面直线关系的方法；对双视图，提出了利用自共轭三角形和对极几何约束，提取任意直线的消失点的算法，并在此基础了提出了一种利用消失元素的3D不变量解释直线间、直线与平面间、平面间等多种空间几何关系的方法。

Of the top of the superior aortic recess extended to the level of the aortic arch from which the branchiocephalic trunk arises. At the level of the aortic arch, 100%of the lymph nodes of superior vena cava were located among the aortic arch, superior vena cava and trachea. At the level of azygos vein, 100%of the lymph nodes of azygos vein and the superior aortic recess were located among the superior vena cava, arch of azygos vein, trachea and concavity of aortic arch.

主动脉弓和奇静脉弓在同一横平面占20.00%±7.30%，40.00%±8.94%的奇静脉弓在主动脉弓凹面平面；②80.00%±7.30%的主动脉上隐窝上界位于主动脉弓右前端头臂干起始处；③在主动脉弓平面，腔静脉后淋巴结位于主动脉弓、上腔静脉和气管之间，出现率为100%；④在奇静脉弓平面，奇静脉弓淋巴结和主动脉上隐窝位于上腔静脉、奇静脉弓、气管和主动脉凹面所围成的气管前间隙内。

The Go moved backward with 1.35mm and upward with 1.90mm in group I, the gonial angle increased for 3.69°, and angle between palatal plane and mandibular plane was increased for 5.00°; In group II, the Go moved backward with 1.85mm and upward with 3.32mm , the gonial angle increased for 4.06°, and angle between palatal plane and mandibular plane was increased for 5.22°. Both in group I and II, there was a tread for clockwise rotation of mandibular corpus. The length of pterygomasseteric sling was mild increased due to the backward movement of Go.

在Go点的变动方面，在Me点向前位移的族群里，术后Go点平均向后1.35mm，向上1.90mm， gonial angle 平均增大3.69度，腭平面与下颚平面的夹角则是增加5.00度；在Me点向后位移的族群里，术后Go点平均向后1.85mm，向上3.32mm， gonial angle 平均增大4.06度，腭平面与下颚平面的夹角则是增加5.22度，不论是向前或是向后的族群，结果皆显示翼咀嚼肌悬吊带有轻微被拉长的迹象。

Through Hilbert transform, a signal's plane trace can be get. There are two frequencies in the tested signal, so the signal's plane trace may be looked as the track of the out pole's end when two poles rotate around parallel axles. Using the knowledge of motion synthesis in theory mechanics, a formula to describing the change of plane trace's step length and angle for two-frequency be get. So we may prolongate the tested signal's plane trace from the echo's initial arriving moment, and get a certain length of the signal's prolongation.

通过Hilbert变换可得到测试信号的平面迹线，测试信号中只含有两个频率成分，视为双频信号，双频信号的平面迹线相当于两连杆绕平行轴转动时外杆杆端迹线，利用理论力学中运动合成和瞬心知识，推导出双频信号平面迹线步长平方满足余弦线性复合函数，而迹线转角可视为线性变化，据此可对回波到来之前的测试信号平面迹线作延长，得到一定长度的信号延展段，信号延展段与实测段作差可得到一次、二次回波的第一个波峰值。

The basis of static, flat汇交system of forces, torque and couple Department of plane, plane general system of forces, center of gravity and centroid, the internal force and internal force diagram, tension and compression, torsion, bending, stress analysis and strength of the theory of the stability bar , the point of movement, the basic rigid-body movement, points of complex, rigid body planar motion, the movement of particle differential equations, dynamic general theorem, static and dynamic method.

静力学基础、平面汇交力系、力矩与平面力偶系、平面一般力系、重心和形心、内力和内力图、拉伸和压缩、扭转、弯曲、应力状态分析和强度理论、压杆的稳定性、点的运动、刚体的基本运动、点的复合运动、刚体的平面运动、质点的运动微分方程、动力学普遍定理、动静法。

Such facemasks have several designs. One type is affixed to the head with two ties, conforms to the face with the aid of a flexible adjustment for the nose bridge, and may be flat/pleated or duck-billed in shape. Another type of facemask is pre-molded, adheres to the head with a single elastic band, and has a flexible adjustment for the nose bridge. A third type is flat/pleated and affixes to the head with ear loops.

这类口罩有几种设计，其中一类靠两根带子固定在头部，在鼻梁处的调节可以弯曲，帮助口罩贴近脸部，形状是平面/平面打褶或鸭嘴状；另一类是模压成杯罩状的口罩，靠一根松紧带固定在头部，鼻梁处的调节也可以弯曲；第三类也是平面/平面打褶的形状，用耳带固定在头部。

By studying psychological effect and traditional cultural effect in plane design, this article proposed that more attention should be paid to the study on psychology of embracers, to inherit and develop the form and connotation of traditional culture.

通过对当代平面设计中心理效应和传统文化效应的分析研究，提出了在平面设计中应注重受众心理－需求的研究，继承和挖掘传统文化的形式与内涵的观点，并在平面设计中进行揉和设计，提高平面设计的艺术亲和力和感染力。

The complexes areneutral as shown by values of molar conductivity in aqueous solution, namely,〓 The crystal structure determinations show that, in complexes, metal ions werecoordinated by four nitrogen atoms and form slightly distorted square planar configuration,relationship between fluorene ring plane and coordination plane is similar to those betweenpeptide planes of β-folding in proteins. The complex molecules linked by hydrogen bonds formone dimension chain or two dimension network structure.

摩尔电导测定表明他们都是二氧四胺中酰胺氮去质子化后形成的产物。X-射线衍射晶体结构测定表明〓的铜、镍配合物的配位多面体都是稍微畸变的平面正方形，配合物分子中芴基平面与配位平面的关系类似于蛋白质β-折叠结构中肽平面之间的关系，配合物分子之间通过氢键连接成一维链状或二维网状结构。

For the application of Mathematica in the differential geometry,this paper introduces how to processe the curve curvature and the torsion questions,the graphic expression of the curvature and the torsions,and draw curves by the curvature and the torsions. Curvature ; torsion ; solution curve ; osculating plane ; natural parameter ; natural equation

利用Mathematica，只要输入有关系统命令就可以得到期望的结果。1曲率和挠率及其图形意义假设R3上的曲线一般参数表示为r=r它的曲率和挠率计算公式是：κ=‖r′×r&‖‖r′‖3τ=‖r′×r‖我们知道，空间曲线r=r在一点(s=s0)邻近的近似方程为ξ=sη=120κs2ζ=160κ0τs3通过近似方程可以确定曲线在其基本三棱形的三个平面(即密切平面，法平面，从切平面)上的投

The contents of this dissertation are involved in studies on quasi steady-state condition of a slow speed-varying rotor system, gain-scheduling control of a quasi steady-state rotor active balancing system, adaptive control of active balancing for a fast speed-varying rotor with actuator time delay and adaptive control of active balancing for a fast speed-varying rotor with actuator saturation. The rotors to be studied include a Jeffcott rotor, a Jeffcott rotor with anisotropic bearings, a flexible rotor with single collocated balancing plane (actuator plane and measuring plane are almost the same one) and a flexible rotor with multiple collocated balancing planes.

研究的内容涉及慢变速转子的准稳态条件、变速准稳态转子主动平衡系统的增益调度控制、带作动器时迟的快变速转子主动平衡系统的自适应控制与带作动器饱和的快变速转子主动平衡系统的自适应控制，转子类型包括Jeffcott转子、轴承各向异性的Jeffcott转子、单并置平衡平面(作动器和测量平面几乎在同一个平面)的柔性转子和多并置平衡平面的柔性转子。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了