检索结果-内蒙古大学图书馆

conference on current developments in Lens design and optical engineering XvIII

作者： Essameldin, Mahmoud Fleischmann, Friedrich Henning, Thomas Lang, Walter Bremen Univ Appl Sci Fac Elect Engn & Comp Sci 30 Neustadtswall D-28199 Bremen Germany Univ Bremen Inst Microsensors Actuators & Syst Otto Hahn AlleeGebaude NW 1 D-28359 Bremen Germany

ISBN: (纸本)9781510612082;9781510612075

The design of a secondary optical lens for light beam shaping using the transformation method is performed by transforming the light source energy distribution using the concepts of energy conservation and light energy mapping. Using these concepts creates a dependency relation between the output optical performance and the luminous intensity distribution of the light source. This relation leads to errors on the optical performance due to the fabrication misalignment between the light source and the secondary optical lens. On the other hand, in the illumination applications, the integration method has been proved to be an efficient method for achieving a high degree of homogenized luminous intensity distribution by integrating and superimposing the light source energy over the illuminated objects. In signal lighting applications, the luminous intensity distribution must meet the requirements regarding the brightness perception of users over the spatial angular distribution, not the illumination of objects. In this paper, the integration method is combined with the transformation method to design a refractive lens-array for signal lighting applications. The difference between the two methods is described, presenting the advantages of the combination process. design procedures are explained in detail including the lens-array modeling. The optical performance is investigated using an optical ray tracing. Finally, the influence of the misalignment between the light source and the refractive lens-array is measured.

关键词： optical design Signal Lighting Beam-shaping

来源：评论

学校读者我要写书评

暂无评论

Parametric 3D Modeling of Low Perveance Elleptical Electron Beams for Devices of THz Range

Parametric 3D Modeling of Low Perveance Elleptical Electron ...

引用

International conference on Actual Problems of Electron Devices engineering, (APEDE)

作者： I.A. Navrotsky A.A. Burtsev A.v. Danilushkin JSC «SPE “Almaz”» Saratov

This report presents the results of 3D modeling of an electron optical system with low perveance electron elliptical beams. The comparison of triple elliptical beams with continuous sheet and elliptical beams has been conducted. The studied systems have a triode design with an anode potential of 20 kv and a grid potential of 950 v. The total current of electron beams is a 93 mA. Results of 3D modeling show that using of electron optical system forming triple elliptical beams in THz devices permits to achieve a high current transmission through a beam tunnel of a slow-wave structure with a dimension of 140×2500 ¼m 2 and provide interaction with the higher transverse mode of three RF field variations.

关键词： Electron beams Three-dimensional displays conferences Electron optics Electric potential vacuum electronics

来源：评论

学校读者我要写书评

暂无评论

vertical cavity surface emitting laser of 1.55 μm spectral range, manufactured by molecular beam epitaxy and wafer fusion technique

引用

Journal of Physics: conference Series 2020年第1期1697卷

作者： S A Blokhin M A Bobrov N A Maleev A A Blokhin A P vasyl'ev A G Kuzmenkov S I Troshkov v M Ustinov S S Rochas A G Gladyshev I I Novikov L Ya Karachinsky K O voropaev A S Ionov A Yu Egorov Ioffe Institute St. Petersburg 194021 Russia Research and Engineering Center for Submicron Heterostructures for Microelectronics St. Petersburg 194021 Russia ITMO University St. Petersburg 197101 Russia Connector Optics LLC St. Petersburg 194292 Russia OKB-Planeta PLC Veliky Novgorod 173004 Russia

The heterostructure design for 1.55 μm range vCSELs is proposed and realized. The wafer fusion technique was used to form the final heterostructure. The growth of AlGaAs/GaAs distributed Bragg reflectors (DBRs) on GaAs substrate and the optical cavity with an active region on InP substrate as well as a tunnel junction (TJ) regrowth was performed by molecular beam epitaxy (MBE). A key feature of the proposed design is the use of n++-InGaAs/p++-InGaAs/p++-InAlGaAs TJ, which allows, due to the effective removal of oxide from the InGaAs surface, to use MBE for re-growth of the TJ surface relief. Despite of the presence in heterostructure a narrow-gap InGaAs layers, a noticeable increase in internal optical loss in lasers can be avoided due to the short-wavelength shift of the edge of interband light absorption in ++-InGaAs layers (Burshtein-Moss effect). Fabricated vCSELs demonstrate single-mode operation with a threshold current less than 2 mA and a slope efficiency of ~ 0.46 W/A, which are comparable with characteristics of vCSELs with n++/p++-InAlGaAs TJ with a similar level of mirror losses.

关键词：

来源：评论

学校读者我要写书评

暂无评论

v-shaped Nano-Antennas on Titanium Dioxide as a Tunable Plasmonic Lens

V-shaped Nano-Antennas on Titanium Dioxide as a Tunable Plas...

引用

Iranian conference on Electrical engineering (ICEE)

作者： Mahmood Rafaei-Booket Mahdieh Bozorgi Faculty of Electrical and Computer Engineering University of Zanjan Zanjan Iran

A tunable planar lens metasurface composed of a gold array on a Titanium dioxide slab is presented. Each cell of such a structure comprised of a v-shaped gold nano-antenna on a uniaxial anisotropic substrate. In the design of such a planar lens, the phase diagram of the cross-polarized scattered field is obtained using a spectral domain calculation based on dyadic Green's function. This function, which is obtained by employing the transmission line (TL) model, appears in an integral equation. By solving the integral equation using Galerkin's Method of Moments (MoM) with the appropriate entire domain functions, the effective surface current densities on the gold array is determined. A series of v-shaped elements with the different dimensions are selected, based on the equal optical length principle, to satisfy the phase discontinuities of each cell. Finally, the lens metasurface illuminated by the plane wave is analyzed by using an electromagnetic simulator. The obtained results indicate the optic axis rotation of the anisotropic substrate leads to controlling the intensity of the lens focuses.

关键词： Lenses optical scattering Substrates Integrated optics Titanium Adaptive optics Method of moments

来源：评论

学校读者我要写书评

暂无评论

A critical look at design automation solutions for collaborative MDO in the AGILE paradigm 19th

A critical look at design automation solutions for collabora...

引用

19th AIAA/ISSMO Multidisciplinary Analysis and Optimization conference, 2018

作者： van Gent, Imco Aigner, Benedikt Beijer, Bastiaan La Rocca, Gianfranco Flight Performance and Propulsion Section Faculty of Aerospace Engineering TU Delft Kluyverweg 1 Delft2629 HS Netherlands Institute of Aerospace Systems RWTH Aachen University Wuellnerstrasse 7 Aachen52062 Germany Solutions Department KE-works Molengraaffsingel 12 Delft2629 JD Netherlands

ISBN: (数字)9781624105500

ISBN: (纸本)9781624105500

This paper presents a critical discussion on the automated problem formulation and workflow creation approach developed within the European project AGILE to support and accelerate the setup of aircraft MDO workflows in a large, heterogeneous team of experts. The developed framework is based on a methodological approach, called the AGILE paradigm, where a complete MDO system is formulated and executed in five main steps. In Step I the requirements are collected, in Step II a repository of disciplinary tools is established, in Step III the design optimization problem is formulated and structured according to a selected MDO architecture, in Step Iv an executable workflow is assembled and finally operated in Step v. All steps have been streamlined and highly automated through the development of a novel set of MDO support applications and data standards, addressed as the AGILE MDO framework. This framework was tested through a series of design campaigns culminating with four design tasks, where a variety of unconventional aircraft configurations is collaboratively designed using MDO. After a brief introduction on the AGILE paradigm and the four design tasks, this paper will focus on a set of AGILE framework core components enabling the automated process to formulate and execute collaborative MDO systems. The strengths and current limitations of these components are discussed, based on the extensive feedback from the heterogeneous set of specialists involved in the four design tasks. Although drastic reductions in the setup time of an MDO system (up to 40 percent) appear to be already achievable, recommendations are provided to improve the flexibility, usability and scalability of the framework. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Aircraft

来源：评论

学校读者我要写书评

暂无评论

Modelling Methods in Solving Research and design Problems in Architecture Activities

引用

IOP conference Series: Materials Science and engineering 2020年第3期753卷

作者： N A vasilenko Belgorod State Technological University named after V.G. Shukhov Kostyukova str. 46 Belgorod 308012 Russia

The modern architectural and city-planning science requires combining the efforts of a number of various research teams, including representatives of different branches of scientific knowledge, with the purpose of designing the most rational and efficient methods of research organization. Due to the dynamic nature of architectural and city-planning objects and quick alteration of the parameters of their elements and components, prompt methods of solving research, designing or forecasting problems are necessary. The era of the fifth technological paradigm is characterized with the establishment of such branches of industry as electronics, microelectronics, information technologies. Since 2010ies we live in the phase of the sixth technological paradigm development, in which the production processes are based on cloud infrastructure and virtual services. One of methodological preconditions in the further development of architecture is the search for optimal solutions in the process of research and designing developments, which could be the most quickly and efficiently implemented by means of computers and information models. For this purpose, first of all, the appropriate formalization of architectural objects is necessary – i.e. creating functional mathematical models and software products for implementing the process of research and solutions optimization in computing techniques. current studies in the sphere of architecture more and more lead to realizing the necessity of system approach to research and designing of architectural objects as complicated systems, having the hierarchic structure. The most promising are the system methods of research, designing and expert evaluation of architectural objects of any degree of complexity.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Tantalum Pentoxide Waveguides and Microresonators for vECSEL-based Frequency Combs 8

Tantalum Pentoxide Waveguides and Microresonators for VECSEL...

引用

conference on vertical External Cavity Surface Emitting Lasers (vECSELs) vIII

作者： Sverre, T. Chen Woods, J. R. C. Shaw, E. A. Hua, Ping Apostoulopoulos, v. Wilkinson, J. S. Tropper, A. C. Univ Southampton Dept Phys & Astron Highfield Rd Southampton SO17 1BJ Hants England Univ Southampton Optoelect Res Ctr Highfield Rd Southampton Southampton SO17 1BJ Hants England

ISBN: (数字)9781510615168

ISBN: (纸本)9781510615168;9781510615151

Tantalum pentoxide (Ta2O5) is a promising material for mass-producible, multi-functional, integrated photonics circuits on silicon, exhibiting robust electrical, mechanical and thermal properties, as well as good CMOS compatibility. In addition, Ta2O5 has been reported to demonstrate a non-linear response comparable to that of chalcogenide glass, in the region of 3-6 times larger than that of materials such as silica (SiO2) or silicon nitride (Si3N4). In contrast to Si-based dielectrics, it will accept trivalent ytterbium and erbium dopant ions, opening the possibility of on-chip amplification. The high refractive index of Ta2O5 is consistent with small guided mode cross-section area, and allows the construction of micro-ring resonators. Propagation losses as low as 0.2 dB/cm have been reported. In this paper we describe the design of a planar Ta2O5 waveguides optimised for the generation of coherent continuum with near infrared pulse trains at kW peak powers. The Pulse Repetition Frequency (PRF) of the vECSEL can be tuned to a sub-harmonic of the planar micro-ring and the optical pump power applied to the vECSEL can be adjusted so that mode-matching of the vECSEL pulse train with the micro-ring resonator can be achieved. We shall describe the fabrication of Ta2O5 guiding structures, and the characterisation of their nonlinear and other optical properties. Characterisation with conventional lasers will be used to assess the degree of coherent spectral broadening likely to be achievable using these devices when driven by mode-locked vECSELs operating near the current state-of- art for pulse energy and duration.

关键词： vECSEL Mode-locked Frequency Combs Supercontinuum

来源：评论

学校读者我要写书评

暂无评论

design and Implementation of A Power Conversion System On A Bicycle With Utilisation By Sensors

Design and Implementation of A Power Conversion System On A ...

引用

International conference on I-SMAC (IoT in Social, Mobile, Analytics and Cloud) (I-SMAC)

作者： Rohith S Prabhu Neeraj vasudev O P v Nandu K J Lokesh J Anudev Department of Electrical and Electronics Engineering Amrita School of Engineering Amrita Vishwa Vidyapeetham Amritapuri India

ISBN: (纸本)9781538614433;9781538614426

It is evident that the rate of cycling nowadays has reduced even though the benefits are lump sum. Being physically active has posed to be a challenge in the current generation. Power that is developed from human beings can be manipulated for major developments in any country. Heart related diseases, obesity, sugar levels and many major illnesses can be taken under control by regular physical activity. This paper focuses on design and implementation of a cycle that can be used as a routine basis where the user is able to generate power by cycling. Such a design that is ergonomic, efficient and safe for use in normal livelihood. Physical activity monitoring systems, energy consumed, conversion systems are designed and implemented here.

关键词： Batteries Sensors Global Positioning System voltage control Bicycles Generators Wheels

来源：评论

学校读者我要写书评

暂无评论

110 pA, 170 ppm/v, -77 dB@100Hz voltage reference for IoT systems

110 pA, 170 ppm/V, -77 dB@100Hz voltage reference for IoT sy...

引用

International conference on Solid-State and Integrated Circuit Technology

作者： Huachao Xu Yao Chen Jinlong Hu Hongyan Cai Tao Du Ke Liang Guofeng Li College of Electronic Information and Optical Engineering Nankai University Tianjin China Advanced Digital Sciences Center Singapore School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin China

A pico-watt voltage reference (vR) for IoT systems is proposed in this paper. By employing a pre-regulation technique, the proposed vR achieves an ultra-high performance of line regulation (LR) and PSRR. Based on a standard 0.18-μm CMOS process, the temperature-independent characteristics of this design are obtained by taking advantage of the threshold voltage (v TH ) differences for 5 v and 1.8 v PMOS transistors. Simulation results show that the proposed vR achieves a temperature coefficient (TC) of 16 ppm/°C over the temperature range of 0 °C to 120 °C with a 1.2 v supply voltage. The total current consumption is 110 pA at 27 °C with an LR of 170 ppm/v over the supply voltage ranges of 1.2 v to 2.7 v while the corresponding PSRR is -77 dB at 100 Hz.

关键词： MOSFET Temperature dependence Threshold voltage Temperature distribution Standards

来源：评论

学校读者我要写书评

暂无评论

Contact lens design with slope-constrained Q-type aspheres for myopia correction 18

Contact lens design with slope-constrained Q-type aspheres f...

引用

conference on current developments in Lens design and optical engineering XvIII

作者： Peng, Wei-Jei Cheng, Yuan-Chieh Hsu, Wei-Yao Yu, Zong-Ru Ho, Cheng-Fang Abou-El-Hossein, Khaled Natl Appl Res Labs Instrument Technol Res Ctr Taiwan 20R&D Rd 6Hsinchu Sci Pk Hsinchu 300 Taiwan Nelson Mandela Metropolitan Univ Precis Engn Lab ZA-6031 Port Elizabeth South Africa

ISBN: (纸本)9781510612082;9781510612075

The design of the rigid contact lens (CL) with slope-constrained Q-type aspheres for myopia correction is presented in this paper. The spherical CL is the most common type for myopia correction, however the spherical aberration (SA) caused from the pupil dilation in dark leads to the degradation of visual acuity which cannot be corrected by spherical surface. The spherical and aspheric CLs are designed respectively based on Liou's schematic eye model, and the criterion is the modulation transfer function (MTF) at the frequency of 100 line pair per mm, which corresponds to the normal vision of one arc-minute. After optimization, the MTF of the aspheric design is superior to that of the spherical design, because the aspheric surface corrects the SA for improving the visual acuity in dark. For avoiding the scratch caused from the contact profilometer, the aspheric surface is designed to match the measurability of the interferometer. The Q-type aspheric surface is employed to constrain the root-mean-square (rms) slope of the departure from a best-fit sphere directly, because the fringe density is limited by the interferometer. The maximum sag departure from a best-fit sphere is also controlled according to the measurability of the aspheric stitching interferometer (ASI). The inflection point is removed during optimization for measurability and appearance. In this study, the aspheric CL is successfully designed with Q-type aspheres for the measurability of the interferometer. It not only corrects the myopia but also eliminates the SA for improving the visual acuity in dark based on the schematic eye model.

关键词： aspheric contact lens Q-type aspheres myopia spherical aberration schematic eye model visual acuity best-fit sphere

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：