周期性的

This paper presents an IFMC CAD model that consits of a geometry model and a material model, in which the geometry space acts as a base space and the material space acts as a bundle space. In this CAD model, the geometry model is based on the non-manifold model. In addition, a half-face data sturucture, which is derived from the half-edge data structure with the non-manifold feature of IFMC taken into account, is adopted to represent the geometry and topology information of the component. For the material model of IFMC, this paper focuses on the FGM component representation firstly and present a simplex-subdivision based CAD data exchange format, in which the material information is represented as a (n-1) simplex and material distributing feature is represented by the interpolation on the simplex-subdivision. Based on those, a part-building orientation optimization algorithm and an adaptive slicing algorithm for FGM component are presented in the paper. For the IFMC material model, the IFMC material information representation is divided into a meso-scale and a macro-scale representation. In the meso-scale, a concept named parameterized periodic functional meso-structure is presented as a unique form to represent the FGM (the homogeneous materials are regarded as a special FGM), the composite and the functional meso-structure material. The model of PMS is a three-tuple that contains the space state informatation, the material parameter and the material meso-scale distribution feature. The macro-scale material information representation is similar to the FGM components by interpolation of the control parameter of the periodical functional meso-structure based on the simplex-subdivision. Through an example of manufacturing-oriented IFMC CAD data processing, it is proved that the IFMC CAD model and the material information representation and process method proposed in this paper can provide a reliable data support for IFMC digital concurrent design and manufacturing.

本文将理想材料零件CAD模型建立在以几何空间为底空间、以材料空间为丛空间的结构上，使用非流形几何模型作为理想材料零件几何拓扑模型的基础，并在半边数据结构基础上，针对理想材料零件的非流形特征局限内部边界上的特点，给出了一个半面数据结构来表述零件的几何拓扑信息；对于理想材料零件的材料模型，本文先从功能梯度材料零件的信息表述与CAD数据交换和处理入手，将材料信息表述为（n-1）维单纯形，然后通过对三维几何区域的单纯剖分，以插值的方式表述零件材料分布特征；在此基础上，根据功能梯度材料零件分层制造中对CAD数据处理的要求，给出了综合考虑零件几何特征与材料特征的生长方向优化算法和自适应切片算法；而对于文中所定义的理想材料零件，本文将其材料信息表述分解到细观和宏观两个尺度进行，首先给出了细观尺度上参数化的周期性功能细结构概念，以此来统一表述功能梯度材料（单质材料作为特殊的功能梯度材料看待）、复合材料和功能细结构材料；把周期性功能细结构模型化为一个包含空间状态信息、材料构成参数和材料细观分布特征参数的三元组，以表达零件的细观材料特征；对于零件宏观的材料变化特征，则同样在几何区域单纯剖分的基础上，通过对细观尺度上周期性功能细结构控制参数的插值来完成；通过理想材料零件CAD数据处理的算例，验证了本文中理想材料零件CAD模型及材料信息表述与处理方法完全可以为理想材料零件的数字化制造提供可靠的数据支持。

This paper presents an IFMC CAD model that consits of a geometry model and a material model, in which the geometry space acts as a base space and the material space acts as a bundle space. In this CAD model, the geometry model is based on the non-manifold model. In addition, a half-face data sturucture, which is derived from the half-edge data structure with the non-manifold feature of IFMC taken into account, is adopted to represent the geometry and topology information of the component.For the material model of IFMC, this paper focuses on the FGM component representation firstly and present a simplex-subdivision based CAD data exchange format, in which the material information is represented as a (n-1) simplex and material .distributing feature is represented by the interpolation on the simplex-subdivision. Based on those, a part-building orientation optimization algorithm and an adaptive slicing algorithm for FGM component are presented in the paper.For the IFMC material model, the IFMC material information representation is divided into a meso-scale and a macro-scale representation. In the meso-scale, a concept named parameterized periodic functional meso-structure is presented as a unique form to represent the FGM (the homogeneous materials are regarded as a special FGM), the composite and the functional meso-structure material. The model of PMS is a three-tuple that contains the space stateinformatation, the material parameter and the material meso-scale distribution feature. The macro-scale material information representation is similar to the FGM components by interpolation of the control parameter of the periodical functional meso-structure based on the simplex-subdivision.Through an example of manufacturing-oriented IFMC CAD data processing, it is proved that the IFMC CAD model and the material information representation and process method proposed in this paper can provide a reliable data support for IFMC digital concurrent design and manufacturing.

本文将理想材料零件CAD模型建立在以几何空间为底空间、以材料空间为丛空间的结构上，使用非流形几何模型作为理想材料零件几何拓扑模型的基础，并在半边数据结构基础上，针对理想材料零件的非流形特征局限内部边界上的特点，给出了一个半面数据结构来表述零件的几何拓扑信息；对于理想材料零件的材料模型，本文先从功能梯度材料零件的信息表述与CAD数据交换和处理入手，将材料信息表述为(n-1)维单纯形，然后通过对三维几何区域的单纯剖分，以插值的方式表述零件材料分布特征；在此基础上，根据功能梯度材料零件分层制造中对CAD数据处理的要求，给出了综合考虑零件几何特征与材料特征的生长方向优化算法和自适应切片算法；而对于文中所定义的理想材料零件，本文将其材料信息表述分解到细观和宏观两个尺度进行，首先给出了细观尺度上参数化的周期性功能细结构概念，以此来统一表述功能梯度材料(单质材料作为特殊的功能梯度材料看待)、复合材料和功能细结构材料；把周期性功能细结构模型化为一个包含空间状态信息、材料构成参数和材料细观分布特征参数的三元组，以表达零件的细观材料特征；对于零件宏观的材料变化特征，则同样在几何区域单纯剖分的基础上，通过对细观尺度上周期性功能细结构控制参数的插值来完成；通过理想材料零件CAD数据处理的算例，验证了本文中理想材料零件CAD模型及材料信息表述与处理方法完全可以为理想材料零件的数字化制造提供可靠的数据支持。

In some materials with periodic variation of dielectric constants and light within a certain frequency range shows exponential decay due to destructive interference and cannot propagate. This phenomenon is called photonic bandgap and this kind of structures is called photonic crystals.

介电系数周期性排列的材料，部分波段会因破坏性干涉呈指数衰减，导致无法在此结构上传播，此现象称为光子能隙，此类具有介电系数周期性排列的结构则称为光子晶体。

This method can be used to analyze the dispersive characteristic of arbitrary mode SWS with arbitrary boundary in theory.

论文首先在直角坐标系下，给出了FDTD差分方程和周期性边界条件的具体形式，并编写程序，分析了周期性加载金属片矩形波导的色散特性。

Furthermore, Fourier-type periodic DOE is one of the most important kinds of DOEs. Therefore, based on scalar diffraction theory, this project will study the efficiency limit of static and dynamic Fourier-type periodic DOEs.

又傅氏周期性绕射光学元件为最重要的绕射光学元件种类之一，故本计画将依据纯量绕射理论，深入研究傅氏周期性绕射光学元件的绕射效率上限。

It may be periodic or nonperiodic, i.e., it may or may not exhibit a regular period of repetition.

它可能是周期性或非周期性，那就是说，它可能或者可能不呈现一规则的周期的重复。

In this paper, the precise parameters of transmission properties of the periodic defected ground structures and nonperiodic defected ground structures are obtained on the basis of FDTD analysis.

本文针对周期性缺陷接地结构和非周期性缺陷接地结构的传输特性进行了FDTD数值分析，得到了它们精确的传输特性曲线。

In the last chapter of this paper, we compute and analyze different kinds of portfolio in Chinese "A share" market including low-profit, high-profit, seasonal and nonseasonal.

最后论文计算分析研究了中国a股市场中绩差股、绩优股、周期性股和非周期性股投资组合的在险价值。

This paper described the principle of plane ultrasonic spreading abroad in the liquid coming into being ultrasonic grating,educed the density and refractive index changing rule basis continuity equation of not-ideal liquid and Lorentz-Lorenz law,expressing the transformation of the index and refractive index satisfaction similar equation of standing wave,and described the relation curve of the standing wave form at a few special times,liquid density and refractive index periodic variety according to the res...

描述了平面超声波在液体里传播形成超声光栅的原理；根据非理想流体对应的连续性方程和Lorentz-Lorenz定律，推导了液体光栅中液体密度与折射率的周期性变化规律，表明液体密度和折射率变化满足相似的驻波方程；根据推导的结果描绘了几个特殊时刻的驻波波形、液体密度、折射率周期性变化之间的关系曲线；进而由折射率周期性变化规律分析了超声驻波自身像的形成原理，并给出了CGS型超声光栅声速仪利用超声驻波自身像测量声速的方法与实验结果。

Objective To research a method to detect the event of periodic leg movements during sleep based on accelerometer and to design a monitoring system by wireless sensors network.

目的研究基于加速度传感器检测睡眠中周期性腿动事件的方法，并采用无线传感器网络技术形成周期性腿动事件监测系统。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷