期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
大气湍流下光学平面面形的估计
1
作者 李琳 刘永辉 《光学技术》 CAS CSCD 北大核心 2023年第6期704-710,共7页
针对大气湍流环境下光学元件平面面形PV值测量这一问题。首先建立了一种大气湍流下斐索干涉仪的模型,通过该模型得到1000张干涉条纹图像;然后提出了一种基于卷积神经网络估算PV值的方法,将干涉条纹图像作为卷积神经网络的输入,利用卷积... 针对大气湍流环境下光学元件平面面形PV值测量这一问题。首先建立了一种大气湍流下斐索干涉仪的模型,通过该模型得到1000张干涉条纹图像;然后提出了一种基于卷积神经网络估算PV值的方法,将干涉条纹图像作为卷积神经网络的输入,利用卷积神经网络提取图像的特征信息,得到PV值;最后将得到的结果与ASTM计算得到的结果、相位解包裹得到的结果以及BP神经网络得到的结果进行对比,发现利用卷积神经网络的方法偏差为2.25×10^(-4)λ,较ASTM、相位解包裹以及BP神经网络得到的结果偏差更小。实验结果表明此方法具有抗干扰性强、精度高、运算快的优点,是一种有效的抗大气湍流影响的光学检测方法。 展开更多
关键词 大气湍流 平面面形测量 卷积神经网络 斐索干涉仪
下载PDF
基于ASTM方法的光学平面面形检测 被引量:1
2
作者 李晋惠 王飞 范博洋 《光学仪器》 2015年第1期4-8,共5页
为分析光学平面面形偏差,以直径100mm光学平晶为检测对象,利用斐索干涉仪采集了被测光学平面的波面干涉图,按照美国材料与试验协会(American Society for Testing and Materials,ASTM)标准方法,通过分析,能够定性反映出被测光学平面的... 为分析光学平面面形偏差,以直径100mm光学平晶为检测对象,利用斐索干涉仪采集了被测光学平面的波面干涉图,按照美国材料与试验协会(American Society for Testing and Materials,ASTM)标准方法,通过分析,能够定性反映出被测光学平面的面形偏差。计算并分析了波面偏差指标峰谷值PV和均方根值RMS,将计算结果与利用ZYGO斐索干涉仪测得的数据对比,偏差为10-3λ,符合光学检测要求。综合考虑可操作性和计算精度,这种基于ASTM的方法是一种行之有效的光学检测分析方法。 展开更多
关键词 斐索干涉仪 干涉图 平面面形检测 ASTM方法
下载PDF
平面面形动态干涉仪
3
作者 武晓东 刘振江 +1 位作者 黄玮 王一凡 《应用光学》 CAS CSCD 1998年第6期9-11,共3页
本文所介绍的平面面形动态干涉仪主要用于解决空间相机成像胶片面不平度的检测,也可用于其它光学平面和非光学平面面形的测试。
关键词 平面面形检测 不平度 斜入射干涉法 动态干涉仪 相机成像胶片
下载PDF
白光多光束干涉细分法测量平面面形
4
作者 陶海林 《海军医高专学报》 1994年第4期314-316,共3页
本文介绍了一种超精光学平面的检测方法-白光多光束干涉细分法.在扼要阐明原理的同时,给出了一套实用的测量装置,并对其细分误差进行了估算.
关键词 多光束 干涉 测量 平面面形
下载PDF
基于五棱镜扫描技术测试大口径平面镜的系统设计 被引量:15
5
作者 马冬梅 韩昌元 《电子测量技术》 2007年第11期90-95,共6页
根据五棱镜扫描测试技术建立了大口径平面镜面形测试系统。对测试系统结构的设计与组成进行了阐述,分析了在实现大口径轮廓扫描时,主要影响测试精度的因素和影响形式;通过计算给出了五棱镜制造误差与扫描机构导向误差对角度测试的综合... 根据五棱镜扫描测试技术建立了大口径平面镜面形测试系统。对测试系统结构的设计与组成进行了阐述,分析了在实现大口径轮廓扫描时,主要影响测试精度的因素和影响形式;通过计算给出了五棱镜制造误差与扫描机构导向误差对角度测试的综合影响趋势,得出了轮廓测试过程中法线角度改变量测试误差主要受导轨精度影响的结论。在导轨导向精度设计为俯仰与偏摆角10″、滚动偏角20″时,系统测试光线角度变化量在扫描方向上最大为0.000969694″,可满足测试要求(系统测角精度为0.02″)。通过计算机模拟,进行了多条带区域轮廓图拼接实验,与干涉图比对,验证了该系统的可行性。 展开更多
关键词 大口径平面测试 五棱镜误差 扫描机构导向精度 轮廓图拼接
下载PDF
建筑平面能耗系数的推导与应用——以斯宅传统民居为例 被引量:1
6
作者 池方爱 徐利明 彭昌海 《工业建筑》 CSCD 北大核心 2021年第4期31-39,共9页
建筑体形系数计算式包含的因子有建筑的长、宽和高,把长和宽两因素进行组合,即为建筑的底层平面形态。通过DesignBuilder软件模拟与分析发现:建筑平面面形系数与底层面积和建筑能耗息息相关,其中建筑能耗与面形系数呈正比关系,与底层面... 建筑体形系数计算式包含的因子有建筑的长、宽和高,把长和宽两因素进行组合,即为建筑的底层平面形态。通过DesignBuilder软件模拟与分析发现:建筑平面面形系数与底层面积和建筑能耗息息相关,其中建筑能耗与面形系数呈正比关系,与底层面积呈反比关系,并由此推导出建筑平面能耗系数算式。为揭示斯宅传统民居平面能耗系数在宏观层面的分布特征,借助G.E.软件分析各子区域内的一字形平面民居、L形平面民居、凹字形平面民居和回字形平面民居的分布规律和频数统计特征,再应用所推导算式计算各个子区域内的民居平面能耗系数。在子区域统计数据基础上进行综合分析得出:天井院民居的节能效果最好,三合院民居次之,折角民居再次之,单体民居最差。 展开更多
关键词 建筑平面能耗系数 民居 建筑平面面形系数 斯宅
原文传递
First-principles thermodynamics of metal-oxide surfaces andinterfaces:A case study review 被引量:4
7
作者 江勇 许灿辉 蓝国强 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期180-192,共13页
An important step for achieving the knowledge-based design freedom on nano-and interfacial materials is attained by elucidating the related surface and interface thermodynamics from the first principles so as to allow... An important step for achieving the knowledge-based design freedom on nano-and interfacial materials is attained by elucidating the related surface and interface thermodynamics from the first principles so as to allow engineering the microstructures for desired properties through smartly designing fabrication processing parameters.This is demonstrated for SnO2 nano-particle surfaces and also a technologically important Ag-SnO2 interface fabricated by in-situ internal oxidation.Based on defect thermodynamics,we first modeled and calculated the equilibrium surface and interface structures,and as well corresponding properties,as a function of the ambient temperature and oxygen partial pressure.A series of first principles energetics calculations were then performed to construct the equilibrium surface and interface phase diagrams,to describe the environment dependence of the microstructures and properties of the surfaces and interfaces during fabrication and service conditions.The use and potential application of these phase diagrams as a process design tool were suggested and discussed. 展开更多
关键词 metal oxide surface phase diagram interface phase diagram equilibrium crystal shape FIRST-PRINCIPLES THERMODYNAMICS
下载PDF
A Study on the Usability of Semiotics in Graphic Design
8
作者 Chunyue Zhao 《International Journal of Technology Management》 2017年第1期26-28,共3页
Currently, The current flat design has become a mainstream approach is widely used in web design, computer and mobile phone systems, interface design. In graphic design, graphic symbol design is increasingly being tak... Currently, The current flat design has become a mainstream approach is widely used in web design, computer and mobile phone systems, interface design. In graphic design, graphic symbol design is increasingly being taken seriously and use minimalist design symbols often appear in print design plane, PPT presentations, public areas, identity-oriented system like. This paper discusses the design of graphical symbols flat in graphic design use need to make the audience cognitive ability, graphic symbols standardized principles, design principles angles for effective information design to achieve efficient information communication. Materialized mostly graphic image symbols, and mostly flat graphic indicator; flat screen symbol by the proposed development materialized symbol interface evolved. Materialized the graphical interface and the graphical interface is flat coexist and cannot replace each other. During the design, the designer should be based on the advantages and disadvantages of the two styles complement each other interfaces, common graphical interface design services. 展开更多
关键词 FINE FLAT graphic design SEMIOTICS usability studies
下载PDF
Analysis of Soil arching effect for Blind sheet-pile wharf based on ABAQUS
9
作者 LIU YaWei WANG LiJuan 《International English Education Research》 2016年第4期51-54,共4页
Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by AB... Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by ABAQUS sot'cware to study the impact of cross section type, the pile spacing and soil properties on soil arching effect. We find that cross section type of the pile has a certain influence on soil stress distribution in front of the barrier piles by comparing circular cross section and rectangular cross section. We also find that clear distance between the barrier piles and cohesive force of the soil have a great influence on that impact. We can increase clear distance between the barrier piles appropriately to improve the efficiency of construction and reduce the proiect cost. 展开更多
关键词 Blind sheet-pile wharf barrier piles earth pressure soil arching effect
下载PDF
Analysis of the shape of heavy droplets on flat and spherical surface 被引量:4
10
作者 WANG XueWei YU Yang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第6期1118-1124,共7页
In this study,a theoretical model was established for predicting the equilibrium shape of the droplet on flat and spherical surfaces.The theoretical equilibrium shape of heavy droplets could be obtained once contact a... In this study,a theoretical model was established for predicting the equilibrium shape of the droplet on flat and spherical surfaces.The theoretical equilibrium shape of heavy droplets could be obtained once contact angle and volume of droplets were given.It showed that the predictions of the theoretical flat model were in good agreement with the shape obtained by Surface Evolver when the contact angle is below 120 and the droplet size is on the order of capillary length.This available range will decrease and increase when the heavy droplet is on convex and concave spherical surface,respectively,in contrast to that on flat surface.The available range will decrease more for higher curvature of convex spherical surfaces. 展开更多
关键词 equilibrium shape heavy droplet ellipsoidal model Surface Evolver simulation
原文传递
A fake projective plane constructed from an elliptic surface with multiplicities (2,4) 被引量:1
11
作者 KEUM JongHae 《Science China Mathematics》 SCIE 2011年第8期1665-1678,共14页
Given any (2,4)-elliptic surface with nine smooth rational curves,eight (2)-curves and one (3)-curve,forming a Dynkin diagram of type [2,2][2,2][2,2][2,2,3],we show that a fake projective plane can be constructed from... Given any (2,4)-elliptic surface with nine smooth rational curves,eight (2)-curves and one (3)-curve,forming a Dynkin diagram of type [2,2][2,2][2,2][2,2,3],we show that a fake projective plane can be constructed from it by taking a degree 3 cover and then a degree 7 cover.We also determine the types of singular fibres of such a (2,4)-elliptic surface. 展开更多
关键词 fake projective plane properly elliptic surface cyclic covering
原文传递
THE GAUSS MAP OF TIMELIKE SURFACES IN R1^n
12
作者 HONG JIANQIAO(Institute of Mathematics, Fudan University, Shanghai 200433, China.) 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1995年第3期361-370,共10页
Gauss maps of oriented timelike 2-surfaces in are characterized, and it is shown that Gallss maps can determine surfaces locally as they do in case. Moreover, some essential differences are discovered between the prop... Gauss maps of oriented timelike 2-surfaces in are characterized, and it is shown that Gallss maps can determine surfaces locally as they do in case. Moreover, some essential differences are discovered between the properties of the Gauss maps of surfaces in Rn and those of the Gauss maps of timelike surfaces in. In particular, a counterexample shows that a nonminimal timelike surface in cannot be essentially determined by its Gauss map. 展开更多
关键词 Timelike surface Gauss map External surface.
原文传递
Lattices,Diophantine equations and applications to rational surfaces 被引量:2
13
作者 XU Mang ZHANG JiaJin 《Science China Mathematics》 SCIE 2012年第6期1189-1196,共8页
In this article,we study certain quadratic Diophantine equations in Picard lattices of blow-ups of the complex projective plane,and describe their relations with root systems and Weyl group orbits of quasiminuscule fu... In this article,we study certain quadratic Diophantine equations in Picard lattices of blow-ups of the complex projective plane,and describe their relations with root systems and Weyl group orbits of quasiminuscule fundamental weights.We apply these to study the geometry of certain rational surfaces. 展开更多
关键词 rational surface quasi-minuscule representation Picard lattice
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部