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1.
压电材料静力耦合机理的三维解析及简化分析   总被引:2,自引:0,他引:2  
在三维压电材料本构方程的基础上,推导出了用位移和电势表示的三维横观各向同性材料的平衡微分方程.考虑到平面问题的广泛性,推导得到了三维压电材料的弹性常数在二维情况下的表达式,为二维理论分析作出了准备.同时,还考察了受垂直于极性轴的轴向力的压电材料的三维解析解,得到了这种情况下的位移和电势分布情况.进而,简单分析了压电材料中弹性常数与工程常数之间的关系  相似文献   

2.
本文建立有边界的二维与三维无序结构的数学模型,证明了Voronoi网络的全萌性与无隙性定理,给出判定皮肤细胞核的有效算法,用数学方法解决有界Voronoi网络的结构问题.  相似文献   

3.
以三维为主线的工程图学教学模式研究   总被引:1,自引:0,他引:1  
胡玉霞  曹秀鸽  谷莉 《甘肃科技》2009,25(9):177-179
从工程设计的发展方向出发,阐述了三维CAD最终将取代二维CAD、三维工程图也将取代二维工程图的发展趋势,结合企业与教学实际分析了三维与二维工程图在将来的一段时间内还会并存的必然性,提出了以三维为主线的工程图学教学改革模式;以三维建模为主线,并与传统内容恰当融合,将三维几何建模贯穿于教学全过程,同时贯彻二、三维并重的思想;在绘图技能训练上,同时注重徒手绘图、二维绘图软件和三维造型软件的使用。  相似文献   

4.
岩体结构面三维循环加载本构关系   总被引:2,自引:0,他引:2  
研究岩体结构面在循环加载条件下的三维力学性质。通过对二维数值模型合理推广,建立三维本构模型。法向加卸载本构为逐步硬化的双曲线函数。切向模型基于加载为双曲线函数、卸载为线性函数的本构方程建立,并引入剪切方向角描述三维切向接触特性。考虑峰值剪切现象,以切向塑性功为主要参数,建立峰值摩擦角和剪胀角的磨损方程。以初始剪胀角和残余剪胀角为主要参数建立剪胀方程。数值计算结果与试验曲线的对比表明,该模型体现了各向异性结构面的非线性受力变形特性、表面磨损和不均匀剪胀行为,能较好模拟三维循环加载本构关系。  相似文献   

5.
二维设计与三维设计的分析比较与图形转换   总被引:1,自引:0,他引:1  
分析比较了二维设计和三维设计的方法与特点,利用二维工程图进行三维模型的设计,以提高建模速度为目标,介绍了将现有的AutoCAD二维工程图转换为Solidworks中的三维实体模型的方法.  相似文献   

6.
为了精确地计算反应性温度系数,采用动态规划的方法,求出了燃耗过程中控制棒的临界棒位。利用组件计算软件包TPFAP,计算慢化剂(或燃料)在不同温度下组件的宏观截面。用节块格林函数法,求解三维中子扩散方程,求得慢化剂(或燃料)反应性温度系数。对于200MW核供热堆在临界棒位下,作了三维反应性温度系数的计算,并与二维计算结果作了比较。结果表明,慢化剂温度系数的大小和控制棒插入有密切关系。二维无控制棒时计算的反应性温度系数比较接近三维带控制棒的计算结果,并且二维无控制棒的计算结果是一个保守的估值。  相似文献   

7.
本文提出了一种在三维形貌测量的结构光投影中使用二维Paul连续小波变换处理结构光栅的方法,与二维Morlet小波相比,二维Paul小波对三维物体高度变化较大的数据恢复效果较好,降低了三维形貌测量中的测量误差,提高了测量精度.  相似文献   

8.
探究了二维动画与三维动画融合的软件技术,即使用Flash、Animo软件创作"伪三维"效果.使用After Effects软件创作"准三维"效果;使用Maya、3ds Max软件创作"真三维"效果.论述了用三维技术表现二维动画效果,三维动画与二维动画穿插运用的融合艺术.认为把二维动画与三维动画巧妙地融合成一种组合型动画,互相取长补短,能给观众呈现出全新的视觉感受,将是现代动画创新与发展的一条新路.  相似文献   

9.
1.引言关于利用有限几何中子空间来构作PBIB设计,万哲先等同志作了一系列的研究,基本上完成了利用1维非迷向子空间作处理来构作PBIB设计的工作。本文试用一类2维双曲型非迷向子空间作处理的集合,构作PBIB设计。文中的符号和术语与[1]一致,结合方案与PBIB设计的定义为熟知。设E_q表示特征数≠2的q元域。当δ=0,1或2时,分别取或  相似文献   

10.
信息时代的来临使传统的二维信息表达不能满足新的需要,计算机的发展使显示和描述物体的三维几何特征和属性特征成为可能,研究二维环境下地图信息的有效表达是当前的一项紧迫任务在空间三维可视化经过前期的发展以后重视对二维地图符号系统的特点在新条件下的作用研究,是地图制图科学螺旋式上升的辩证观。该文详细探讨了三维环境中二维地图符号中优势,论证了三维可视化环境与二维地图符号的关系。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

19.
20.
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has  相似文献   

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