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特种铸造及有色合金 2018年第7期38卷 701-704页

作者：李庆芬吴远志邓彬李理刘伟叶拓刘安民湖南工学院机械工程学院湖南工学院汽车零部件技术研究院汽车泵类零部件设计制造技术国家地方联合工程实验室

对ZK60镁合金进行不同温度固溶处理,采用浸泡腐蚀、电化学测量研究了固溶处理后合金在模拟体液(SBF)中的腐蚀性能。利用OM(金相观察)与SEM(扫描电镜)对合金组织、腐蚀产物和腐蚀形貌进行观察,并使用EDS对腐蚀产物成分进行分析。结果表明... 详细信息

对ZK60镁合金进行不同温度固溶处理,采用浸泡腐蚀、电化学测量研究了固溶处理后合金在模拟体液(SBF)中的腐蚀性能。利用OM(金相观察)与SEM(扫描电镜)对合金组织、腐蚀产物和腐蚀形貌进行观察,并使用EDS对腐蚀产物成分进行分析。结果表明,经固溶处理后,铸态合金中第二相逐步溶解,降低了合金基体与第二相的电位差,使合金电偶腐蚀和局部腐蚀的倾向减弱,耐腐蚀性能提高。经330℃固溶处理后的ZK60合金,腐蚀速率为2.573mm/a,腐蚀电流密度与腐蚀电位分别为0.205mA/cm^2和-1.504v,生物耐腐蚀性能理想。

关键词： ZK60镁合金固溶温度模拟体液生物腐蚀性能

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optical design of an ultrashort throw ratio projector with two freeform mirrors 17

Optical design of an ultrashort throw ratio projector with t...

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Conference on current developments in Lens design and optical engineering XvII

作者： Nie, Yunfeng Mohedano, Ruben Benitez, Pablo Chaves, Julio Minano, Juan C. Thienpont, Hugo Duerr, Fabian Vrije Univ Brussel Dept Appl Phys & Photon Brussels Photon Team Pleinlaan 2 B-1050 Brussels Belgium Light Prescript Innovators Madrid 28223 Spain Light Prescript Innovators Altadena CA 91001 USA Univ Politecn Madrid CeDint Campus Montegancedo Pozuelo Madrid 28223 Spain

ISBN: (数字)9781510602861

ISBN: (纸本)9781510602854;9781510602861

In this work, an optical design approach is presented to design an ultrashort throw distance projection system by combination of an off-the-shelf refractive lens and two off-axis freeform mirrors. These two freeform mirrors are used to greatly shorten the projection distance by more than three times compared to conventional (rotationally symmetric) systems, while still maintaining a good imaging quality. Firstly, a direct design method that enables the simultaneous calculation of two off-axis freeform-profile mirrors by partially coupling more than three fields is introduced. The specifications of the conventional refractive lens are taken into account during this procedure. The pupil matching principle is applied to ensure good performance between the two sub-systems. The calculated mirrors then serve as a good starting point for optimization using commercial optical design software. To step from freeform profiles to freeform surfaces, the calculated two profiles are fitted into odd polynomials to evaluate the image quality and then re-fitted into XY polynomials for further optimization. Finally, the polynomial coefficients of the two freeform mirrors are imported into the optical design program. The merit function is built from RMS spot radii over the full field, and additional constraints are made for correcting distortion. After optimization, the calculated initial design quickly converges to a well performing imaging system. As an example, an ultrashort throw distance projection lens with a large 80-inch diagonal image at 400mm throw distance is designed, analyzed and compared with literature data. The values of MTF are over 0.6 at 0.5 lp/mm and the distortion is less than 1.5%: showing a very good and well balanced imaging performance over the entire field of view.

关键词： geometric optics ultrashort throw ratio projector optical design aspheric mirrors freeform optics

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current status of ITER I&C system as integration begins

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FUSION engineering AND design 2016年 112卷 788-795页

作者： Davis, William Wallander, Anders Yonekawa, Izuru ITER Org Route Vinon Sur VerdonCS 90 046 F-13067 St Paul Les Durance France Nippon Adv Technol Ltd 3129-45 Hibara Muramatsu Tokai Ibaraki 3191112 Japan

The ITER l&C system is organisationally complicated and technically challenging, and integrating its many sub-systems into a single coherent system is critical for the ITER project to meet its objectives. This paper explains the integration risks being faced now and anticipated in the near future. Standardisation initiatives by the ITER central team to mitigate these risks are described. The paper also presents the architecture of the ITER I&C system, the current status of design and manufacture key developments made in recent years, and the current and future activities of the central I&C teams. Finally, a short description is given of the plant I&C systems that will be delivered to ITER in the near future. (C) 2016 ITER Organization. Published by Elsevier B.v. All rights reserved.

关键词： CODAC Integration Interlocks Nuclear Safety ITER

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Evolution of photonic metasurfaces: from static to dynamic

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JOURNAL OF THE optical SOCIETY OF AMERICA B-optical PHYSICS 2016年第3期33卷 501-510页

作者： Shaltout, Amr M. Kildishev, Alexander v. Shalaev, vladimir M. Purdue Univ Dept Elect & Comp Engn Birck Nanotechnol Ctr W Lafayette IN 47906 USA

The realization of commercial photonic devices based on three-dimensional optical metamaterials is challenged by large absorptive losses as well as complex and costly fabrication. Metasurfaces-two-dimensional metamaterials-have been introduced to overcome these major challenges. They provide simple, compact, and power efficient solutions to problems of immense importance in photonics design. In addition to the strong potential of metasurfaces to enable next generation optical devices, their reduced dimensionality also allows for new physical effects which do not have volumetric counterparts. Furthermore, various technologies are presently emerging to provide modulation of metasurface response using mechanical, electrical, or optical control. Although the general purpose of these approaches is to obtain tunable versions of static metasurfaces, recent studies have uncovered that the impact of dynamic metasurfaces far exceeds tunability alone and comprises new physical effects such as Lorentz nonreciprocity. Here we start with reviewing recent developments of static metasurface devices and their applications. Then we discuss the burgeoning area of dynamic metasurfaces and demonstrate current evolving technologies to achieve time-varying properties and their conceivable applications. (C) 2016 optical Society of America

关键词： Beam shaping Negative index materials optical devices optical metamaterials Polarization control Superlenses

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Comprehensive vertical-cavity surface-emitting laser model for optical interconnect transceiver circuit design

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optical engineering 2016年第12期55卷

作者： Wang, Binhao Sorin, Wayne v. Palermo, Samuel Tan, Michael R. T. Texas A&M Univ Dept Elect & Comp Engn 235i WEB3128 TAMU College Stn TX 77843 USA Hewlett Packard Enterprise Hewlett Packard Labs 1501 Page Mill RdMS1123 Palo Alto CA 94304 USA

Directly modulated vertical-cavity surface-emitting lasers (vCSELs) are commonly used in short-reach optical interconnect applications. To enable efficient optical interconnect transceiver systems operating at data rates up to 25 Gb/s and beyond, cosimulation environments, which allow for the optimization of driver circuitry with accurate compact vCSEL models, are necessary. A comprehensive vCSEL model, which captures thermally dependent electrical and optical dynamics and provides direct current, small-, and large-signal simulation capabilities with self-consistency, is presented. The device's electrical behavior is described with an equivalent circuit, which captures both large-signal operation and electrical parasitics, while the optical response is captured with a rate-equation-based model. Bias and temperature dependencies are incorporated into both key electrical and optical model parameters. Experimental verification of the model is performed at 25 Gb/s with a 990-nm vCSEL to study the impact of bias current level and substrate temperature. (C) 2016 Society of Photo-optical Instrumentation Engineers (SPIE)

关键词： semiconductor lasers electro-optics optical interconnects

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Anaerobic digestion of pulp and paper mill wastes - An overview of the developments and improvement opportunities

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CHEMICAL engineering JOURNAL 2016年 298卷 162-182页

作者： Kamali, Mohammadreza Gameiro, Tania Costa, Maria Elisabete v. Capela, Isabel Univ Aveiro CESAM Ctr Environm & Marine Studies Dept Environm & Planning P-3810193 Aveiro Portugal Univ Aveiro CICECO Aveiro Inst Mat Dept Mat & Ceram Engn P-3810193 Aveiro Portugal

various organic and inorganic hazardous substances are commonly originated during the processing of virgin or recovered fibers (RCFs), when the pulp and paper (P&P) are produced. Hence, pulp and paper industry (PPI) strongly need to employ advanced waste treatment processes as a powerful tool to comply with the stringent environmental regulations in one hand, and to increase their profitability in the current declining P&P markets, on the other hand. Among the treatment alternatives, anaerobic digestion (AD), is an interesting cost-effective alternative with a small environmental footprint and has been increasingly adopted by the PPI to reach this goal. However, the application of AD to deal with wastes generated in P&P mills has been restricted due to a number of limitations, regarding the anaerobic reactor design and the operating conditions. Hence, the optimization of the AD performance would be a crucial step in order to increase the economic benefits, and also to satisfy the strict environmental protection standards. To this end, this paper presents an overview on the current state of the developments associated with AD treatment of P&P mill wastes to assess the applicability of this treatment process for the management of this type of complex wastes. In this context, suggestions are provided to maximize both biogas production and removal efficiency, focusing on the relationship between waste composition and reactor design and operational conditions, which will enhance methane capture and contribute to prevent global warming. (C) 2016 Elsevier B.v. All rights reserved.

关键词： Pulp and paper industry Wastewater Sludge Anaerobic digestion Methane production

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Subsea projects cost Reduction - Petrobras approach, results and next steps

Subsea projects cost Reduction - Petrobras approach, results...

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Offshore Technology Conference, OTC 2017

作者： Gomes, F. Moreira Matoso Ribeiro Dal Pont, A. Arantes, F. Maia Freitas, G. A. Cavalcanti Marques, M. A. Rodrigues De Souza Salvador, M. Poli, P. R. Santos De Oliveira, R. Caldeira Laquini, S. Dos Santos, T. Duarte Fonseca Gasparetto, v. Petrobras S.A. United States

ISBN: (纸本)9781510842083

The Oil and Gas industry has faced an unpredictable and fast transformation in the last years. At first, there were barrel prices over U$ 100 dollars, which motivated a huge worldwide investment that pushed operators and the supply chain to respond to unprecedented growth. Due to the downturn in the oil prices, the challenge has moved towards achieving project feasibility in a low Brent scenario. The Brazilian subsea oil and gas industry has struggled with this context. Initially, with the Pre-Salt discoveries in 2006 it was necessary to develop breakthrough technological solutions to face this new frontier and to build 10 ultra deep-water production systems happen in just 10 years. Due to the recent price drop, Petrobras subsea engineering area has faced a demand to develop simpler and cost efficient solutions to reduce Pre-Salt CAPEX and OPEX. The objective of this paper is to review how Petrobras subsea area is dealing with these challenges since the discovery of Pre-Salt in 2006 until the current downturn of the oil and gas industry. As a reaction to that, Petrobras has been running an internal strategy called Subsea Cost Reduction Plan - PRCSub. The main purpose of this program is to search for the biggest cost reduction opportunities and to promote a full integration among Petrobras subsea team and suppliers. The PRCSub has delivered excellent results. Around US$ 500 million in savings were registered between 2014 and 2015 in the subsea scope, and between 25% of CAPEX reduction was achieved in Pre-Salt developments due to optimization initiatives for subsea design. The paper will present a review of the initiatives, describing the technical solutions and the new business model under construction by Petrobras. Copyright 2017, Offshore Technology Conference.

关键词： Cost reduction

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design and Simulations of Plasmonic Planar Fiber to Chip Coupler Works at the optical Communication Wavelength

Design and Simulations of Plasmonic Planar Fiber to Chip Cou...

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Progress in Electromagnetic Research Symposium

作者： A. Kuzma F. Uherek J. Chovan M. Donoval International Laser Centre Bratislava Slovak Republic Faculty of Electrical Engineering and Information Technology Slovak University of Technology in Bratislava Bratislava Slovak Republic

Transmitting, splitting, and coupling of optical power are fundamental applications in photonics integrated circuits, which can be designed and fabricated on various material platforms. Material platforms characterized by high refractive index contrast allow higher integration of photonic devices into photonic integrated circuit, but mode field diameter of waveguides based on high refractive index material platform is more than 20 times smaller in comparison to mode field diameter of single mode optical fiber. This makes it more difficult coupling optical radiation from optical fiber to photonic integrated circuit. current designs of optical couplers require complex technical and fabrication technology solutions with 100 nm resolution and less. Planar fiber to chip coupler, operating at wavelengths using in optical communication systems, based on enhancing surface plasmon polaritons requires for its production simple and more generally available technological steps operate with lower resolution. We report the design of plasmonic coupler and simulation of its properties by finite-difference time-domain (FDTD) simulation method.

关键词： Plasmons Couplers optical coupling optical sensors Gratings optical refraction optical variables control

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design investigation of a cost-effective dual-band (MWIR/LWIR) and a wide band optically athermalized application 17

Design investigation of a cost-effective dual-band (MWIR/LWI...

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Conference on current developments in Lens design and optical engineering XvII

作者： Ding, Fujian Washer, Joe Morgen, Daniel ISP OPT 50 S Buckhout St Irvington NY 10533 USA

ISBN: (数字)9781510602861

ISBN: (纸本)9781510602854;9781510602861

Dual-band and wide-band lenses covering both the MWIR and LWIR spectral bands are increasingly needed as dual-band MWIR/LWIR detectors have become prevalent and broadband applications have expanded. currently in dual-band /wide-band applications, the use of more than three elements per lens group and the use of chalcogenide glass is common. This results in expensive systems. Also, many chalcogenides are available only in small diameters, which is a problem for large aperture broadband lenses. In this paper an investigation of cost-effective designs for dual-band MWIR/LWIR lens using only widely available IR materials, specifically Ge, ZnSe and ZnS were performed. An athermalized dual-band MWIR/LWIR using these three materials is presented. The performance analysis of this lens shows that this design form with these three common IR materials works well in certain applications. The required large size blanks of these materials can be easily obtained. Traditional chromatic aberration correction without diffraction for either wide-band or dual-band application was employed. In addition, the methods of harmonic diffraction for dual-band applications, especially with one narrow band, were used for two different presented designs.

关键词： IR Imaging IR Wide-band Lens Dual-band Lens Athermalization Chromatic Aberration Correction Harmonic diffraction

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design of a portable demonstration unit of solar power systems for analog electronics courses 124

Design of a portable demonstration unit of solar power syste...

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124th ASEE Annual Conference and Exposition

作者： Kim, Yoon Maitra, Shurjo Calvin College United States

This paper presents a practical approach to improving the knowledge and awareness of solar power systems by using a demonstration unit in an analog electronics course. The unit AIDS instructors in teaching an introductory-level laboratory experiment focused on solar power harvesting and storage and enables instructors to bring in a functional system into labs or classrooms for upper-class undergraduate electrical and computer engineering students. The unit can be used to demonstrate many of the aspects of solar power systems, helping instructors address sustainability and renewable energy issues. Solar power systems based on photovoltaic (Pv) cells have been successfully deployed as renewable energy sources. They have become one of the promising technologies, providing a sustainable energy source as many natural resources are depleting. Due to the importance and wide acceptance of this technology, a demonstration unit has been developed to introduce solar power systems to students at various stages in their education. The approach to improving the students' knowledge of solar power systems is to integrate students' knowledge and experiences with basic electric circuits acquired from their first electronics course and to enhance their learning about new technologies through hands-on experiments in labs or classroom demonstrations. The unit would help students better understand renewable energy by teaching them how to obtain environment-friendly energy from sunlight. It will provide students with an opportunity to apply their knowledge in science and technology to solve a real-world problem. The unit includes a custom-designed light fixture consisting of thirty (30) high-power LEDs as an optical energy source, two 1-watt solar panels as the energy harvesting devices, a fixture for adjusting the solar panel angle, a battery charge controller, voltage and current meters for measuring power, a variable resistor and switches for measuring the I-v characteristics of the pa

关键词： Students

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