检索结果-内蒙古大学图书馆

2021 European Powder Metallurgy Congress and Exhibition, Euro PM 2021

作者： Köhler, Marie Luise Herzog, Simone Kaletsch, Anke Broeckmann, Christoph Institute for Materials Applications in Mechanical Engineering RWTH Aachen University Germany

ISBN: (纸本)9781899072545

Carbide-rich tool steels are known to be difficult to process by Laser Powder Bed Fusion (LPBF). In order to enhance processability and mechanical properties, alloy development is required. Simultaneously, powder mixtures as feedstock for the LPBF process become increasingly attractive for researchers, as this is a cost-efficient way of alloy development. A high chromium alloyed cold work tool steel, based on conventionally available AISI H13 powder and modified by additions of Cr3C2, Cr and FeCrC powder was processed by LPBF. Different powder particle size distributions were used to characterize their influence on the microstructure of the cold work tool steel. The microstructure is analysed in detail by light optical microscopy, backscattered electron imaging and electron backscatter diffraction. The resulting chemical homogeneity and mechanical properties of the steel are further analysed by optical emission spectroscopy, energy dispersive X-ray spectroscopy and hardness testing. © European Powder Metallurgy Association (EPMA)

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

MCRC v1 Development of integrated readout electronics for next generation X-ray CCD detectors for future satellite observatories 9

MCRC V1 Development of integrated readout electronics for ne...

引用

conference on X-Ray, optical, and Infrared Detectors for Astronomy IX as part of SPIE Astronomical Telescopes + Instrumentation conference

作者： Herrmann, Sven Wong, Josephine Chattopadhyay, Tanmoy Morris, R. Glenn Burke, Barry Prigozhin, Gregory Cooper, Mike Craig, David Donlon, Kevan Foster, Richard Malonis, Andrew Bautz, Mark Allen, Steven Stanford Univ Kavli Inst Particle Astrophys & Cosmol Stanford CA 94305 USA MIT Kavli Inst Astrophys & Space Res 77 Massachusetts Ave Cambridge MA 02139 USA MIT Lincoln Lab 244 Wood St Lexington MA 02173 USA

ISBN: (纸本)9781510636965

The High Definition X-ray Imager (HDXI) for the proposed Lynx X-ray Observatory will require much larger (16 Mpixel) and faster (around 100 fps) imaging detectors than have been developed to date. One engineering solution to meet these requirements is to combine substantial parallelization with fast readout speeds. Stanford University and MIT are collaborating in the development of such detectors. The work involves the design of a new ASIC, the MIT CCD Readout Chip MCRC-v1, developed to read out MIT Lincoln Laboratory CCDs using MOSFET or JFET outputs. The architecture of the MCRC-v1 involves eight low-noise, fully differential amplifiers, each coupled to a fully differential output driver to support waveform sampling with a commercial ADC. The chip also includes an experimental current readout capability to support fixed-bias potential operation of single-electron sensitive readout (SiSeRo) CCD output stages. We will present both the readout concept and circuit details for the MCRC-v1 ASIC

关键词： readout electronics CCD ASIC ROIC integrated circuit X-ray Lynx HDXI

来源：评论

学校读者我要写书评

暂无评论

optical and electrical simulation of single gaas nanowire/ge solar cells 2nd

Optical and electrical simulation of single gaas nanowire/ge...

引用

2nd International conference on Energy Systems, Drives and Automations, ESDA 2019

作者： Kumar, Akshaya Samajdar, Dip Prakash Sachchidanand, v. Deparment of Electronics and Communication Engineering Indian Institute of Information Technology Design and Manufacturing JabalpurMadhya Pradesh482005 India

ISBN: (纸本)9789811550881

In this chapter, we perform a detailed analysis of the optical and electrical properties of GaAs nanowire (NW) over Ge bottom cell, which is significantly influenced by the structural morphology of the NWs. This necessitates the need for geometric optimization of the NWs to enhance the performance metrics of the solar cells. The absorption efficiency per unit volume over traditional bulk and thin-film counterpart are much improved due to the intrinsic antireflection, strong excitation of resonance modes, and optical antenna effects. We show that the diameter optimization of GaAs NW for a fixed D to P ratio of 0.5 resulted in an ideal short circuit current density of 42.32 mA/cm2 with the help of 3D Finite Difference Time Domain method under standard AM 1.5G illumination. The optimized photogeneration profile is then imported to the DEvICE Module for electrical simulation resulting in a PCE of 18.61%, which is significantly higher than its planar counterpart. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2020.

关键词： Open circuit voltage

来源：评论

学校读者我要写书评

暂无评论

Consumer Electronic Optics: How Small a Lens Can Be Using Metasurfaces 20

Consumer Electronic Optics: How Small a Lens Can Be Using Me...

引用

conference on current developments in Lens design and optical engineering XX

作者： Thibault, Simon Univ Laval Ctr Opt Photon & Lasers COPL Quebec City PQ Canada Immervis Inc Montreal PQ Canada

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

Miniature optics are used in many applications and particularly in consumer optics for such products as webcams, mobile phones, automotive components, endoscopes, tablets, and many other connected devices. Mobile phone cameras are probably the ones that have driven the race for shorter TTL over the past 10 years. Ten years ago, cell phone cameras were composed of 3-4 optical plastic elements within one camera lens;today it takes more than 6 optical elements to obtain mega pixel resolution. But it is still not enough. The market has an insatiable appetite for greater optical performance. Consequently, the lens system has become more complex and now may require more optical elements with more complex optical functions. In this context, can the metasurface lens play a role? In this paper, we will try to address this question and discuss how metasurfaces promise to become a game changer in the consumer electronics market.

关键词： Lens design Metasurface Dielectric Nanofin Aberration Cell Phone Camera Phone

来源：评论

学校读者我要写书评

暂无评论

High-voltage high-current vertical geometry Ga2O3 rectifiers 11

High-voltage high-current vertical geometry Ga2O3 rectifiers

引用

Oxide-based Materials and Devices XI 2020

作者： Xian, Minghan Fares, Chaker Carey, Patrick Ren, Fan Tadjer, Marko Liao, Yu-Te Chang, Chin-Wei Lin, Jenshan Sharma, Ribhu Law, Mark E. Raad, Peter E. Komarov, Pavel L. Islam, Zahabul Haque, Aman Kuramata, Akito Pearton, S.J. Dept. of Chemical Engineering University of Florida GainesvilleFL32611 United States Naval Research Laboratory WashingtonDC United States Dept. of Electrical and Computer Engineering National Chiao Tung University Hsinchu Taiwan Department of Electrical and Computer Engineering University of Florida GainesvilleFL32611 United States Department of Materials Science and Engineering University of Florida GainesvilleFL32611 United States Department of Mechanical Engineering Southern Methodist University DallasTX United States TMX Scientific Inc. RichardsonTX75081 United States Department of Mechanical Engineering Penn State University University ParkPA United States Tamura Corporation and Novel Crystal Technology Inc. Saitama350-1328 Japan

ISBN: (纸本)9781510633254

There are continuing rapid developments in vertical geometry Ga2O3 for high voltage switching applications. Ga2O3 is emerging as a viable candidate for certain classes of power electronics with capabilities beyond existing technologies due to its large bandgap, controllable doping and the availability of large diameter, relatively inexpensive substrates. These include power conditioning systems, including pulsed power for avionics and electric ships, solid-state drivers for heavy electric motors and advanced power management and control electronics. There are already cases where the performance exceeds the theoretical values for SiC. Existing Si, SiC (vertical devices), and heteroepitaxial GaN (lateral devices) enjoy tremendous advantages in terms of process maturity, an advantage that is especially true for Si, where the ability to precisely process the material has resulted in devices such as super-junctions that surpass the unipolar "limit". Continued development of low defect substrates, optimized epi growth and surface treatments and improved device design and processing methods for Ga2O3 are still required to push the experimental results closer to their theoretical values. Even 3 μm epi layers with doping concentration of 1016 cm-3 should have a theoretical breakdown voltage of ∼1800v. The actual experimental value of vB is currently well below the theoretical predictions. Thermal management is a key issue in Ga2O3 power devices for practical high current devices and initial studies have appeared on both the experimental and theoretical fronts. We summarize progress in edge termination design, temperature measurement using thermoreflectance-based thermography to measure the thermal rise and decay of the active diodes, failure under forward bias and development of large current (up to 130A) arrays. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Wide band gap semiconductors

来源：评论

学校读者我要写书评

暂无评论

The design of a four-mirror anti-astigmatism astronomical telescope 20

The design of a four-mirror anti-astigmatism astronomical te...

引用

conference on current developments in Lens design and optical engineering XX

作者： Huang, Jiun-Woei Taiwan Instrument Res Inst Natl Appl Labs 20 R&D 6 Rd Hsinchu 30076 Taiwan Natl Taiwan Univ Inst Appl Mech 1 Roosevelt Rd4 Sec Taipei 10617 Taiwan

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

The design of four mirrors anti-astigmatism astronomical telescope is carried out for low earth orbit satellite. By integrating with Cassagrain and Schwartzschild configurations, the telescope is design. It contains four mirrors with conic surface, to form an aberration free. The system contains two parts: first part is the Cassagrain type telescope for pick up the ground object to the stop position, and the second part is Schwartzschild configurations as relay optics, which is to relay the image to high resolution CCD sensor to provide 0.5 ground space distance image. The system is symmetric with aberration free within a one cubic size fitted for small satellite. The optic mechanical is simple easy to assemble for optical calibration, while the body is rigid in space.

关键词： four mirrors anti-astigmatism astronomical telescope small satellite

来源：评论

学校读者我要写书评

暂无评论

SPT-3G+: Mapping the High-Frequency Cosmic Microwave Background Using Kinetic Inductance Detectors 11

SPT-3G+: Mapping the High-Frequency Cosmic Microwave Backgro...

引用

conference on : Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI

作者： Anderson, A. J. Barry, P. Bender, A. N. Benson, B. A. Bleem, L. E. Carlstrom, J. E. Cecil, T. W. Chang, C. L. Crawford, T. M. Dibert, K. R. Dobbs, M. A. Fichman, K. Halverson, N. W. Holzapfel, W. L. Hryciuk, A. Karkare, K. S. Li, J. Lisovenko, M. Marrone, D. McMahon, J. Montgomery, J. Natoli, T. Pan, Z. Raghunathan, S. Reichardt, C. L. Rouble, M. Shirokoff, E. Smecher, G. Stark, A. A. vieira, J. D. Young, M. R. Fermilab Natl Accelerator Lab MS209POB 500 Batavia IL 60510 USA Univ Chicago Kayli Inst Cosmol Phys 5640 South Ellis Ave Chicago IL 60637 USA Univ Chicago Dept Astron & Astrophys 5640 South Ellis Ave Chicago IL 60637 USA Cardiff Univ Sch Phys & Astron Cardiff CF24 3YB Wales Argonne Natl Lab High Energy Phys Div 9700 South Cass Ave Lemont IL 60439 USA Univ Chicago Enrico Fermi Inst 5640 South Ellis Ave Chicago IL 60637 USA Univ Chicago Dept Phys 5640 South Ellis Ave Chicago IL 60637 USA McGill Univ Dept Phys 3600 Rue Univ Montreal PQ H3A 2T8 Canada McGill Univ McGill Space Inst 3600 Rue Univ Montreal PQ H3A 2T8 Canada Canadian Inst Adv Res CIFAR Program Grav & Extreme Universe Toronto ON M5G 1Z8 Canada Univ Colorado Dept Astrophys & Planetary Sci CASA Boulder CO 80309 USA Univ Colorado Dept Phys Boulder CO 80309 USA Univ Calif Berkeley Dept Phys Berkeley CA 94720 USA Univ Arizona Steward Observ 933 North Cherry Ave Tucson AZ 85721 USA Univ Arizona Dept Astron 933 North Cherry Ave Tucson AZ 85721 USA Natl Ctr Supercomp Applicat Ctr AstroPhys Surveys Urbana IL 61801 USA Univ Melbourne Sch Phys Parkville Vic 3010 Australia Three Speed Log Inc Victoria BC V8S 3Z5 Canada Harvard Smithsonian Ctr Astrophys 60 Garden St Cambridge MA 02138 USA Univ Illinois Dept Astron 1002 West Green St Urbana IL 61801 USA Univ Illinois Dept Phys 1110 West Green St Urbana IL 61801 USA

ISBN: (纸本)9781510653627;9781510653610

We present the design and science goals of SPT-3G+, a new camera for the South Pole Telescope, which will consist of a dense array of 34 100 kinetic inductance detectors measuring the cosmic microwave background (CMB) at 220, 285 and 345 GHz. The SPT-3G+ dataset will enable new constraints on the process of reionization, including measurements of the patchy kinematic Sunyaev-Zeldovich effect and improved constraints on the optical depth due to reionization. At the same time, it will serve as a pathfinder for the detection of Rayleigh scattering, which could allow future CMB surveys to constrain cosmological parameters better than from the primary CMB alone. In addition, the combined, multi-band SPT-3G and SPT-3G+ survey data, will have several synergies that enhance the original SPT-3G survey, including: extending the redshift-reach of SZ cluster surveys to z > 2;understanding the relationship between magnetic fields and star formation in our Galaxy;improved characterization of the impact of dust on inflationary B-mode searches;and characterizing astrophysical transients at the boundary between mm and sub-mm wavelengths. Finally, the modular design of the SPT-3G+ camera allows it to serve as an on-sky demonstrator for new detector technologies employing microwave readout, such as the on-chip spectrometers that we expect to deploy during the SPT-3G+ survey. In this paper, we describe the science goals of the project and the key technology developments that enable its powerful yet compact design.

关键词： cosmic microwave background kinetic inductance detectors South Pole Telescope kinematic Suriyaev-Zel'dovich effect

来源：评论

学校读者我要写书评

暂无评论

Beyond the State of the Art of Electric vehicles: A Fact-Based Paper of the current and Prospective Electric vehicle Technologies

引用

WORLD ELECTRIC vEHICLE JOURNAL 2021年第1期12卷 20页

作者： van Mierlo, Joeri Berecibar, Maitane El Baghdadi, Mohamed De Cauwer, Cedric Messagie, Maarten Coosemans, Thierry Jacobs, valery Hegazy, Omar Vrije Univ Brussel VUB Fac Engn Dept Elect Engn & Energy Technol ETEC Mobil Logist & Automot Technol Res Ctr MOBI B-1050 Brussels Belgium Flanders Make B-3001 Heverlee Belgium

Today, there are many recent developments that focus on improving the electric vehicles and their components, particularly regarding advances in batteries, energy management systems, autonomous features and charging infrastructure. This plays an important role in developing next electric vehicle generations, and encourages more efficient and sustainable eco-system. This paper not only provides insights in the latest knowledge and developments of electric vehicles (Evs), but also the new promising and novel Ev technologies based on scientific facts and figures-which could be from a technological point of view feasible by 2030. In this paper, potential design and modelling tools, such as digital twin with connected Internet-of-Things (IoT), are addressed. Furthermore, the potential technological challenges and research gaps in all Ev aspects from hard-core battery material sciences, power electronics and powertrain engineering up to environmental assessments and market considerations are addressed. The paper is based on the knowledge of the 140+ FTE counting multidisciplinary research centre MOBI-vUB, that has a 40-year track record in the field of electric vehicles and e-mobility.

关键词： electric vehicle digital twin wide bandgap semiconductors power converters solid-state batteries ultra-high fast chargers vehicle-to-grid (v2G) vehicle-to-X (v2X) sustainable energy communities renewable energy sources autonomous electric vehicles optical wireless communications

来源：评论

学校读者我要写书评

暂无评论

design of a head-mounted display with freeform mirrors 20

Design of a head-mounted display with freeform mirrors

引用

conference on current developments in Lens design and optical engineering XX

作者： Rui, Congshan Zeng, Chunmei Hu, Tiantian Ma, Suodong Soochow Univ Sch Optoelect Sci & Engn Suzhou 215006 Peoples R China Soochow Univ Educ Minist China Key Lab Adv Opt Mfg Technol Jiangsu Prov Suzhou 215006 Peoples R China Soochow Univ Educ Minist China Key Lab Modern Opt Technol Suzhou 215006 Peoples R China

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

A head-mounted display (HMD) requires a large field of view (FOv) and a large exit pupil diameter while maintaining a compact structure. In this paper, we show a head-mounted display design comprising two freeform mirrors covering a 28 degrees full field-of-view with an eye relief of 15mm. The simplified partial differential equation (PDE) method is applied in the design of a two-mirror HMD system. Then the data points on the unknown freeform mirrors are calculated using the rays from multiple fields and are used to construct the freeform mirrors in the HMD system, which is taken as a starting point. This simplified partial differential equation method makes calculations easier. The anamorphic surface and the XY polynomial freeform surface are used in the two freeform mirrors for improving the image quality, respectively. The optimization strategy is also described in detail. The final HMD system operates at F/3.75 with 8mm exit pupil diameter achieving good imaging performance.

关键词： Geometric optical design mirror system design head-mounted display optical freeform surface

来源：评论

学校读者我要写书评

暂无评论

Self-organizing production systems: Implications for product design 12

Self-organizing production systems: Implications for product...

引用

12th CIRP conference on Intelligent Computation in Manufacturing engineering (CIRP ICME)

作者： Graessler, Iris Hentze, Julian Poehler, Alexander Paderborn Univ Prod Creat Heinz Nixdorf Inst Fuerstenallee 11 D-33102 Paderborn Germany

current developments in production systems and production control will lead to a significant change of their connection to product development. A representative example of these developments is the concept of self-organizing production systems. This paper focuses on appropriate changes of the development process evoked through recent developments in production. The paper summarizes process changes and opportunities for the development process, which include the vision of self-organizing production systems, its challenges and opportunities. Consequences are estimated for established development methodologies like the v-model and aspects of Systems engineering. (C) 2019 The Authors. Published by Elsevier B.v.

关键词： Product development Self-organizing production systems

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：