形状系数

The influence on absorption coefficient brought from shape choice with cylindrical or cone-shaped cavity, square or hexagonal profile, from different closure as air or water, from different material properties and structure sizes, are analyzed based on the numerical calculations. Some general characteristics are summarized. It shows that lowest resonance frequency of sound absorbent coefficient is inversely proportional to volume of cavity and sound absorbent coefficient is proportional to perforated percentage.

2通过数值方法研究了吸声结构内腔为圆柱腔和圆锥腔、基材的剖面形状为正四边形和正六边形、不同背衬、基材材料特性、尺寸大小对整体吸声效果的影响，总结了这些情况下非旋转对称吸声结构的声学特性变化规律，得出腔体体积越大，吸声系数最低共振频率越低；穿孔率越大，吸声系数越大的结论。

In this dissertation, based on the extraction of meaningful polarization information, the polarimetric speckle reduction, polarimetric contrast enhancement, polarimetric classification and ship detection in polarimetric SAR images are systemically studied. During the study, some new concepts and methods are introduced, which are supported by the application to measured Pol-SAR data. The innovations of this dissertation are as follows: 1 A simplified schem is proposed to reduce the complexity of scattering-model-based speckle filtering. 2 Extend the expression of polarimetric correlation coefficient to help distinguishing targets. In addition, introduce the quantized parameters of polarimetric signature so as to show the differentiae in quantity in co-polar power, cross-polar power and shapes of polarization signatures among targets. 3 Define a new parameter of difference degree between targets, which can be used for express the difference between both coherent and distributed scatters.

论文在较系统的研究目标特征量提取方法和特征量所包含的物理意义的基础上，对极化SAR图像降斑、极化对比增强、极化SAR图像分类以及极化SAR图像中海上舰船目标检测等方面进行了研究，并提出了一些新的概念和方法，对实测数据的处理结果表明，这些新的概念和方法对于极化SAR信息处理是有效的，本文的主要创新成果包括以下方面： 1）针对基于预分类的MMSE极化降斑方法实现过程非常复杂的问题，提出了简化方案，并验证了方案的有效性； 2）扩展了极化相关系数的表示方法，这种扩展增强了极化相关系数对目标的区分效果；另外还提出了极化特征图量化参数，可以从量上表征不同目标间相同极化和交叉极化的回波功率差异和极化特征图形状差异； 3）定义了目标间的差异度参数，它不仅可以用于描述相干目标，还可以用于描述分布目标的差别程度。

In order to deal with the irregular cross section of the milling cutter, the cutter effective cross section coefficient and effective radius coefficient are introduced to determine the inherent frequency of cutters for various cantilever lengths and radii.

针对铣刀刀杆截面形状不规则的特点，引入截面系数和有效半径系数的概念，提出了不同悬臂长度和半径的铣刀刀杆固有频率计算方法。

In this paper, a traditional boundary following is improved by using a new algorithm with a criterion to control search. A describes symbols method is proposed by use Fourier coefficient. The way how to calculate these coefficients from chain code is given. Then the calculation formula is further ameliorated. And how to extract shape feature invariant from Fourier coefficient is introduced also.

为此，本文利用带搜索控制准则的新边界跟踪算法改进了传统的边界跟踪算法，提出了用傅立叶系数描述符号，给出了如何由链码计算傅立叶系数，并对计算公式作了进一步改进，以及由傅立叶系数提取形状特征不变量。

As investigated, the shape of the fruit was mainly rotundity, and the color of the fruit were red, black, yellow, mauve. Variation coefficient of mineral elements, which revealed wider variation range and rich genetic diversity. Among them, Fe, the content and the variation coefficient of which was the highest(2.12 mg·100g-1 and 26.99％), it has large potential for futher selection. Ripe fruit of 12 wild myrobalan plum seedlings were analyzed using head space-solid phase microextraction and gas chromatography-mass spectrometry. The results showed considerable genetic variations in these aspects: The total content of volatile components, the classes and contents of each compounds classes, the segregation ratio, and content of main components. There were 83 compounds in total belonging to 6 classes detected in 12 wild myrobalan plum seedlings, including esters, alcohols, ketones, aldehydes, heterocycle and Hydrocarbons. Among them, Formic acid, hexyl ester, the content of which was the highest(4.33 μg·g-1),was important character impact odors.

结果表明，①新疆野生樱桃李实生株系的果实形状主要为圆形，少数为椭圆形、卵圆形、卵形和宽卵形，果实颜色有黄色、红色、紫红色和黑色等4种类型，野生樱桃李果实纵径、横径、单果重、果形指数以及可溶性固形物含量均存在一定程度的变异，遗传多样性较为丰富，其中以单果重的变异系数最大(9.13 %)；②新疆野生樱桃李实生株系果肉组织的Zn、Ca、Mg、Mn、Fe及Cu等6种矿质元素含量变异丰富，其中以Fe元素的含量（平均值为2.12 mg·100g-1）和变异系数（26.99％）最高，进一步筛选高铁性状单株的潜力很大；③从新疆野生樱桃李12个实生株系中共鉴定出醇类、醛类、酯类、酮类、烃类及杂环类等6类83种挥发性化合物，各实生株系挥发性化合物总含量、挥发性化合物种类及其含量以及主要挥发性化合物分离比率与含量等存在广泛的遗传变异，遗传多样性较为丰富，其中以甲酸己酯含量最高（平均值为4.33 μg·g-1），是野生樱桃李果实香气形成的重要特征性化合物。

The quadratic patches is fixed,and its parametric representation method is gained.The cubic patches reduce to three local factors through reducing Bernstein coefficients to control shape of curve,two of them are used to join segments into G2- continuity approximating curves for given sequence data in space,and the other is used to adjust shape of segment.

先固定二次曲面片，并得到其参数形式，然后约简三次曲面片所对应的Bernstein系数，使之为带有三个形状调整的形状因子，其中两个分别代表曲线段端点处的曲率，另外一个作为形状的调整。

Take the opportunity of this project, theoretical and experimental researches on the high-efficiency evaporator used in a large quick-freeze equipment have been done. The main work of experimental research is as follows:(1) Compare and analyze the influences of structural parameters on the heat transfer coefficient of an evaporator. The calculation results show that, under non-freezing conditions, the structure possessing the highest heat transfer coefficient is the one with circular fins, equilateral-triangle arranged small tubes and varying fin-spacing.

主要做了以下几方面的试验研究工作：(1)对不同翅片形状、管径大小、翅片管排列方式，以及是否带波纹等结构参数对蒸发器传热系数的影响进行了比较分析，得出在不结霜工况下，具有最高传热系数的蒸发器结构是圆翅片小管径正三角形排列等节距结构的结论。

Aiming at the research of general scroll profiles and its shape optimization,the coefficient parameter transformation characteristics of general arc functional scroll profiles based on instinct equation oftangent angle coefficient was studied.

针对通用涡旋型线设计及其形状优化，研究了基于切向角参数固有方程的弧函数通用泛函涡旋型线的系数参数变换特性，通过对各系数参数的单独特性分析，掌握了泛函弧函数涡旋型线在各个阶段的特性及其在整个阶段的共性。

The fluid flows and heat coupled calculation method is used. The standards two equations turbulence models, velocity and pressure coupled arithmetic are used.According to the results of numerical simulation analysis the local coefficient distribution changes along the pin fins.Study the effection that its height and shape of the pin fins have on the average Nu and the average number of pressure loss coefficient Eu.The circle-shaped and elliptic-shaped pin fins have different circumcolumnar regional,therefore the mixed conditions are effected.

数值计算中采用标准双方程湍流模型，速度压力耦合算法；根据数值模拟的结果分析沿扰流元的局部换热系数分布变化，研究其扰流柱高度及形状对扰流柱通道平均努赛尔特数Nu和平均压力损失系数Eu的影响，圆形和椭圆形扰流柱的绕流尾涡影响的区域的不同对扰流柱群内流体混合状况的影响。

Both C and C are related with the shape characters of nonspherical particles closely, and C and C vary nonlinearly.

在50≤Re≤300和0≤Ω≤2.0条件下，研究了拖曳速度、旋转速度和颗粒形状对其阻力系数与升力系数的影响。

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