准平面

Three different planar structural modes of 5 approximants have been put forward by using pentagon, decagon, flat hexagon and boat-shape respectively.

从高分辨像出发，分别用十边形，五角形以及扁六边形和船形构筑了五种十次准晶近似相的各三种平面结构模型。

The raw data was processed by using axial, coronal and double oblique multi-planar reformation; Images obtained were graded in terms of quality with a 5-point scale(5=excellent, 4=good, 3=fair, 2=poor, and 1=nondiagnostic). In grading image quality at axial MPR, The radiologic specialists focused on the subarcuate fossa, tendon of tensor tympani, facial recess, vestibular aqueduct and pyramidal eminence, In grading image quality at coronal MPR, attention was given to the scute, crista transversa, fenestra cochleae, lateral malleal ligament and snake eyes signature of cranial nerve, In the grading of the image quality at double oblique MPR, the radiologic specialists concentrated on the malleus, incus, stirrup bone, upper bony semicircular and aquaeductus fallopii, and then to implement statistical analysis. In order to choose the minimum tube current values and the maximum pitch that can satisfy the diagnosis request, image quality of axial, coronal and double oblique reformation images was compared with different tube current groups. 15 ears of volunteers were used to test the validity with the scanning parameter. Subsequently noise, MTF and dose length product were measured by phantoms in different tube current and pitch, the parameters obtained were compared and taken into statistics analysis.

扫描模式使用临床常用的颞骨螺旋扫描方式：管电压120 kV，准直宽度20×0.6 mm，视野200 mm，重建矩阵512×512，旋转时间1 s/r，重建层厚0.6 mm，重建间隔0.3 mm，分别改变管电流(380、300、200、160、120和80 mA)和螺距(0.8、1.0和1.2)进行扫描和重建，然后对颞骨进行横断面、冠状面和双斜面多平面重组，于重组后的横断层面图像上选取弓形下窝、鼓膜张肌腱、面神经隐窝、前庭导水管和锥隆起5个解剖结构，冠状面重组图像上选取盾板、横嵴、蜗窗、面神经的蛇眼征和锤骨外侧韧带5个解剖结构，双斜面重组图像上选取锤骨、砧骨、镫骨、上骨半规管和面神经管5个解剖结构，在双盲的情况下由放射学专家分别对各管电流和螺距下扫描的重组图像进行评分，随后进行统计学处理，从中筛选出满足诊断要求的最低管电流值和最大的螺距，分别采用患者25例(15耳)用该管电流值和螺距验证其可行性；然后利用模体分别测试各管电流和螺距下的图像的空间分辨率、噪声及其剂量长度积，并对测试所得参数数值进行比较和统计学处理。

In order to solve the problem of motion estimation for nonuniformity correction of infrared focal plane arrays,a new fast algorithm for image registration is presented.

为了解决红外焦平面非均匀算法中出现的运动估值问题，提出了一种新的快速图像配准算法。

Plane strain, mode I quasi-static steady state crack growth is investigated utilizing the finite element method. It is once again established that TNT plasticity can significantly increase the stress level near the crack tip. The crack tip stress singularity is higher than or equal to the square-root singularity of elastic K field and is also independent of the plastic hardening exponent.

采用有限元方法研究了平面应变Ⅰ型准静态的稳态裂纹扩展，再次证实TNT非局部理论能够显著提高裂纹尖端附近的应力水平；裂尖应力场的奇异性超过或等于弹性K场平方根奇异性，而且与塑性硬化指数无关。

While the water redistributing, the change of the relative lake level is not even at each point in lacustrine basin and the parasequence sets are also different.

水体发生重新分配过程中，湖盆中各点的相对湖平面变化并不统一，由此产生的准层序组也不一致。

These planation surfaces joined once each other imply that the vast southeastern part of China was in a state of peneplain during late geological period.

这些残留的夷平面曾相互连为一休，暗示我国东南部广大地区在晚近地质时期曾一度处丁准平原状态。

Upstream incision of rivers led to westward motion of boundary between internally and externally drained regions and disappearance of paleo-lakes in Quaternary, and Quaternary incision of external rivers gradually formed present topography characterized by deep valleys, high mountains and remained peneplain in eastern Tibetan Plateau.

中新世晚期-第四纪以湖面与五道梁群湖相沉积顶面为基准，在高海拔环境下继续发生剥蚀夷平和准平原化，逐步形成主夷平面或高原面。第四纪河流溯源侵蚀导致内外流水系分界线自东向西迁移，在青藏高原东部形成高山峡谷地貌。

The higher-order asymptotic solutions of a quasi-static, steadily propagating Mode I plane strain crack in an elastic perfectly plastic material are studied.

本文研究了理想弹塑性材料中Ⅰ型平面应变准静态定常扩展裂纹尖端场的高阶渐近解。

In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.

这章具体研究了基于三种极化散射特性描述的相应的目标识别方法：①基于极化参数平面描述的目标识别方法，将目标回波极化状态投影到以极化椭圆参数，即椭圆率角ε和倾角τ表征的极化状态平面上，参数随观测频率的变化就形成了图，根据图的变化特点构造了目标的多维极化特征空间，并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构；②基于Poincare极化球面描述的目标识别方法，采用Stokes矢量表征目标回波的极化状态，并将其投影到描述极化状态的Poincare极化球面上，定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息，提取了准方位不变性的目标极化特征，最后设计了目标的识别器结构；③基于频率敏感性描述的目标识别方法，通过在Poincare极化球面上所定义的极化状态距离的概念，研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题，获得了在极化状态距离下的频率分布特性曲线，采用最小二乘估计曲线拟合方法，它既用于极化特征的降维，同时又直接将拟合参数作为目标的分类特征。

The specimen produces an image of the collimator reticle in its

样品在它的焦平面上产生一个准直仪十字线的像。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。