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非球面光学元件的制造技术(英文) 总被引:3,自引:1,他引:2
非球面光学元件广泛用于不同领域,但它们的成功应用主要取决于其质量和制造费用。近几年来,通过开发计算机数控光学加工机械和新的制造技术,已经取得了大的进展。本文涉及制作非球面所用的主要技术。总结将指明适合的用途和这些方法中的每一项的技术成就。两个实际的例子表明非球面光学元件的挑战和光明未来。 相似文献
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Recent progress in biomedical sensing technologies has resulted in the development of several novel sensor products and new applications. Modern biomedical sensors developed with advanced microfabrication and signal processing techniques are becoming inexpensive, accurate, and reliable. A broad range of sensing mechanisms has significantly increased the number of possible target measurands that can be detected. The miniaturization of classical "bulky" measurement techniques has led to the realization of complex analytical systems, including such sensors as the BioChemLab-on-a-Chip. This rapid progress in miniature devices and instrumentation development will significantly impact the practice of medical care as well as future advances in the biomedical industry. Currently, electrochemical, optical, and acoustic wave sensing technologies have emerged as some of the most promising biomedical sensor technologies. In this paper, important features of these technologies, along with new developments and some of the applications, are presented. 相似文献
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金属玻璃,又称非晶态合金,因具有长程无序、短程有序的独特组织结构而拥有超常的综合性能,是制造微纳器件的理想材料之一,然而,其易过热变性且禀性钝惰硬脆,是一种典型难加工的材料之一。在分析金属玻璃组织结构特点和力学性能的基础上,按等材、减材和增材3种成形方式对金属玻璃的微制造方法与技术进行了综述。介绍各自的加工与成形原理、工艺特点、技术优势、基础应用和发展现状,分析了它们的不足与发展趋势。目前,等材成形是主流的微成形加工方法,是基于非晶材料内在特性的一种成形方式。减材与增材成形加工现阶段仍处于探索之中,工程应用案例较少,有一定的发展潜力。最后展望了金属玻璃微纳制造领域的未来发展方向与研究重点。 相似文献
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选区激光熔化技术(SLM)被认为是极有前途的增材制造技术之一,但不可逆的溅射行为严重限制了SLM技术的应用。从粉末熔池演变、加工工艺优化和飞溅颗粒动态特征监测等方面,总结了SLM过程中飞溅行为的研究现状,分析了飞溅行为的产生机制,探讨了激光–粉末–熔池相互作用下的熔池演变情况,表明金属蒸气、Marangoni效应和伯努利效应是诱发飞溅的主要因素;讨论了加工工艺与飞溅行为的相互关系,表明通过优化工艺参数和改善打印环境以抑制飞溅是行之有效的方法;阐述了飞溅诱导缺陷的机理,并讨论了SLM过程的监测方法,表明单一信号的局限性会导致监测结果失准,多信号融合监测是提升精准性的重要方法之一。最后,针对飞溅行为存在的关键科学问题和技术难题,展望了SLM加工中飞溅行为的研究方向。 相似文献
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Satnam Singh Dheeraj Gupta Vivek Jain Apurbba K. Sharma 《Materials and Manufacturing Processes》2015,30(1):1-29
The main focused aim of developing new processing and manufacturing technologies are to reduce production or manufacturing costs, processing times, and to enhance manufactured product properties. The developed processing techniques should be widely acceptable for all types of materials including metal matrix composites, ceramics, alloys, and fiber reinforced plastics. Microwave materials processing is emerging as a novel processing technology which is applicable to a wide variety of materials system including processing of MMC, FRP, alloys, ceramics, metals, powder metallurgy, material joining, coatings, and claddings. In comparison to the conventional processes, microwave processing of materials offers better mechanical properties with reduced defects and economical advantages in terms of power and time savings. The present review work focuses mainly on global developments taking place in the field of microwave processing of materials and their relevant industrial applications. 相似文献
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目的 实现新一代信息技术背景下传统铝门窗幕墙型材加工行业的转型升级,以应对复杂型材加工制造存在的成本高、工序繁多等诸多挑战。方法 根据型材加工工艺流程及该行业定制化生产的特点,提出一种涵盖网上下单、订单自动处理、机床智能加工生产的复杂型材智能加工制造系统架构,重点针对自主开发的门窗幕墙型材一站式加工智能机床,研发出一套复杂型材智能加工制造系统。结果 研究了加工信息数字化模型、工艺数据库等关键技术。通过工艺数据库的构建,实现了自动编程系统的搭建。结合Web Service与XML技术,研发出订单自助处理系统、机床智能操作管理系统及其与ERP系统的集成互连,打通了生产各环节之间的技术壁垒,形成了复杂型材一体化加工工艺。结论 实际测试表明,经复杂型材智能加工制造系统一体化制造的复杂型材从接受订单到产品加工完成只需40分钟,大幅提高了生产效率和产品质量,降低了加工成本。本研究为复杂型材智能加工及其他传统制造行业的转型升级提供了有益的借鉴和参考。 相似文献
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Sensor technology is one of the most important key technologies of the future with a constantly increasing number of applications, both in the industrial and in the private sectors. More and more gas sensors are used for the control of technical processes, in environment monitoring, healthcare, and automobiles. Consequently, the development of fast and sensitive gas sensors with small cross sensitivity is the subject of intense research, propelled by strategies based on nanoscience and -technology. Established systems can be improved and novel sensor concepts based on bottom-up approaches show that the sensor properties can be controlled by molecular design. This Review highlights the recent developments and reflects the impact of nanoscience on sensor technology. 相似文献
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Norbert H. Menzler Frank Tietz Sven Uhlenbruck Hans Peter Buchkremer Detlev Stöver 《Journal of Materials Science》2010,45(12):3109-3135
This article summarises recent developments in solid oxide fuel cell research regarding materials, processing and microstructure–property
relationships. In the materials section, the various cell and stack materials are briefly described, i.e. electrolytes, electrodes,
contact and protective layers, interconnects and sealing materials. The section on processing gives an overview of manufacturing
technologies for cells including a view of different substrate materials and designs. Besides the widely used planar cell
designs, the technologies for tubular designs are also described. In addition, the technologies are grouped with respect to
the support, e.g. metal- or ceramic–metal (cermet anode substrate)-supported SOFCs. Finally, special emphasis is laid on the
microstructure of functional layers which primarily govern the power output of the SOFC. 相似文献
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Laugier P 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2008,55(6):1179-1196
Although it has been more than 20 years since the first recorded use of a quantitative ultrasound (QUS) technology to predict bone fragility, the field has not yet reached its maturity. QUS has the potential to predict fracture risk in several clinical circumstances and has the advantages of being nonionizing, inexpensive, portable, highly acceptable to patients, and repeatable. However, the wide dissemination of QUS in clinical practice is still limited and suffering from the absence of clinical consensus on how to integrate QUS technologies in bone densitometry armamentarium. Several critical issues need to be addressed to develop the role of QUS within rheumatology. These include issues of technologies adapted to measure the central skeleton, data acquisition, and signal processing procedures to reveal bone properties beyond bone mineral quantity and elucidation of the complex interaction between ultrasound and bone structure. This article reviews the state-of-the-art in technological developments applied to assess bone strength in vivo. We describe generic measurement and signal processing methods implemented in clinical ultrasound devices, the devices and their practical use, and performance measures. The article also points out the present limitations, especially those related to the absence of standardization, and the lack of comprehensive theoretical models. We conclude with suggestions of future lines and trends in technology challenges and research areas such as new acquisition modes,, advanced signal processing techniques, and modelization. 相似文献
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Liquid resin infusion (LRI) of textile tailored reinforcements (TRs) is increasingly applied in new processing technologies for manufacturing carbon fibre composites. This work presents a cure cycle study of an out-of-autoclave toughened resin film infusion (RFI) process as part of the examination of an alternative manufacturing process for composites. To successfully produce laminates using resin film infusion in combination with a fast-curing process, the flow behaviour of the selected resin material under changed processing conditions was investigated. The effect of processing parameters, specifically heating rates and dwell times, on resin viscosity and laminate infiltration was evaluated through experimental work and supported by in situ process monitoring. A DC-resistance sensor system was applied to track the change in resin viscosity during cure. Results showed that cure cycles with a relatively short dwell time and higher heating rate compared to an autoclave cure led to enhanced flow properties of the toughened resin system. High quality laminates, comparable to autoclave panels, were manufactured with vacuum pressure only by modifying the original vacuum bagging arrangement. 相似文献
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Iver E. Anderson Emma M.H. White Ryan Dehoff 《Current Opinion in Solid State & Materials Science》2018,22(1):8-15
Additive manufacturing (AM) promises to redesign traditional manufacturing by enabling the ultimate in agility for rapid component design changes in commercial products and for fabricating complex integrated parts. By significantly increasing quality and yield of metallic alloy powders, the pace for design, development, and deployment of the most promising AM approaches can be greatly accelerated, resulting in rapid commercialization of these advanced manufacturing methods. By successful completion of a critical suite of processing research tasks that are intended to greatly enhance gas atomized powder quality and the precision and efficiency of powder production, researchers can help promote continued rapid growth of AM. Other powder-based or spray-based advanced manufacturing methods could also benefit from these research outcomes, promoting the next wave of sustainable manufacturing technologies for conventional and advanced materials. 相似文献
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金属增材制造(也称为3D打印)被认为是制造业最有前景的技术之一,主要应用在航空航天领域,用于加工传统方法难以制备的大型复杂零件。该技术面临的一个关键瓶颈是零件的变形,这将严重影响零件的尺寸精度,甚至导致零件开裂而无法使用。首先介绍了研究增材零件变形的主要试验方法,明确了激光位移传感器及数字图像相关技术是研究瞬态变形的有效实验手段。然后介绍了变形预测的数值模拟方法,明确了热源模型、热边界条件及材料的力学性能本构是影响变形预测准确性的主要因素。最后总结了当前国内外变形快速计算方法的研究进展及发展动向。 相似文献
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This paper discusses key technical and economical achievements which have extended the range of application of magnetic separation methods into the commercial processing of micron size feebly magnetic materials. Commercial application of magnetic methods in the cleaning of kaolin clay is reviewed and a discussion of magnetic separation principles is given with emphasis on identification and utilization of important process parameters. Possible future developments in magnetic processing of municipal and industrial wastewaters and of applications of magnetic methods to the preparation of clean fuels from coal are discussed. 相似文献
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新型航天器用镍基高温合金部件呈现出复杂化、薄壁化、复合化、一体化的发展趋势,使得传统的铸造或锻造加工技术无法胜任。基于逐层堆积的激光增材制造(LAM)技术是实现这类复杂部件制备的理想解决方案,能够进一步赋予高温合金更高的价值,极大地推动航天装备的发展。首先介绍了航天领域常用的镍基高温合金种类,然后以研究最多的IN 718和IN 625合金为例,总结了镍基高温合金增材制造的研究现状:归纳了镍基高温合金增材制造工艺优化方法,表明增材制造综合加工图和实验设计方法是两种行之有效的方法;指出了增材制造镍基高温合金材料的微观组织特点,讨论了增材制造后续热处理对材料微观组织和力学性能的影响规律,表明增材制造技术极快速冷却的特点引起镍基高温合金材料内部存在普遍的局部微观偏析现象,导致常规热处理工艺不再是最优工艺;并通过5个典型的增材制造镍基高温合金航天构件案例展示了增材制造技术的优势。在此基础上,针对镍基高温合金增材制造过程中存在的关键科学问题和技术难题,展望了增材制造镍基高温合金未来的研究方向。 相似文献
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Ashwith Chilvery Sanjib Das Padmaja Guggilla Christina Brantley Anderson Sunda-Meya 《Science and Technology of Advanced Materials》2016,17(1):650-658
Perovskite solar cells (PSCs) were developed in 2009 and have led to a number of significant improvements in clean energy technology. The power conversion efficiency (PCE) of PSCs has increased exponentially and currently stands at 22%. PSCs are transforming photovoltaic (PV) technology, outpacing many established PV technologies through their versatility and roll-to-roll manufacturing compatibility. The viability of low-temperature and solution-processed manufacturing has further improved their viability. This article provides a brief overview of the stoichiometry of perovskite materials, the engineering behind various modes of manufacturing by solution processing methods, and recommendations for future research to achieve large-scale manufacturing of high efficiency PSCs. 相似文献