共查询到20条相似文献,搜索用时 48 毫秒
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阻抗匹配是超声波换能器应用和提高超声波换能器性能的关键技术之一.为了研究阻抗匹配对超声波直线送料器性能的影响,制作了一种利用2个郎之万振子分别作为激振器和吸振器从而在输送梁上生成行波,进而形成对物料输送能力的新型超声波送料器.该文主要研究这种送料器系统的吸振振子的阻抗匹配问题,分别制作了矩形截面细长梁和圆形截面细长梁的超声波送料器样机并进行了试验,实测了阻抗匹配的效果及其对送料器输出性能的影响.实验证明,对于Ⅰ型送料盘电感L=18.7 mH,电阻R=15 kΩ;Ⅱ型送料盘L=15.2 mH,R=35 kΩ时实现了阻抗匹配.两种送料盘在阻抗匹配时输送效果最佳. 相似文献
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为了能实现对轻、薄、小物料的稳定输送,提出了一种压电双晶片为驱动源配重式直线振动输送器。设计了压电振动输送器的结构并分析了其工作原理,建立了系统的动力学模型,推导出了双自由度系统的振动位移表达式以及近似得到系统的固有频率,制作了振动输送器的样机,并进行了试验测试。试验结果表明:在系统共振频率为120.5Hz,料道振动位移达到最大,3个测试点分别为39μm,34μm,37μm,但不影响物料输送,工作频率范围为117~124Hz,处于共振频率最大输送速度达到52mm/s。与同型号的电磁式振动输送器相比,在共振条件下研制的样机的电流仅为电磁式的16.58%,速度是其1.36倍,振幅为电磁式的32.38%,噪音降低了33dB。设计的输送器具有送速度稳定、节能、噪音小等优点。 相似文献
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阻抗匹配是超声波换能器应用和提高超声波换能器性能的关键技术之一.为了研究阻抗匹配对超声波直线送料器性能的影响,制作了一种利用2个郎之万振子分别作为激振器和吸振器从而在输送梁上生成行波,进而形成对物料输送能力的新型超声波送料器.该文主要研究这种送料器系统的吸振振子的阻抗匹配问题,分别制作了矩形截面细长梁和圆形截面细长梁的超声波送料器样机并进行了试验,实测了阻抗匹配的效果及其对送料器输出性能的影响.实验证明,对于Ⅰ型送料盘电感L=18.7 mH,电阻R=15 kΩ;Ⅱ型送料盘L=15.2 mH,R=35 kΩ时实现了阻抗匹配.两种送料盘在阻抗匹配时输送效果最佳. 相似文献
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物料输送速度是影响电磁振动供料器输送生产率的重要因素,其料槽的振幅、频率、振动方向角和倾角等参数对物料输送速度有着非常大的影响,本文采用MATLAB软件对电磁振动供料器进行分析及计算,并充分利用MATLAB软件强大的可视化功能,编制相应的程序对计算结果进行可视化,为振动参数的优化设计奠定了基础,对电磁振动供料器的使用提供了理论参考。 相似文献
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宋福民 《电子工业专用设备》2005,34(9):58-61
供料器在贴片机中占有较多的数量,同时也是决定贴片工艺的重要组成部分。随着微型和密间距片式电子元件的广泛应用,贴片速度和精度的提高,对供料器的设计与安装也提出了更高的要求。采用机器视觉的处理手段,使得对带式送料器输送元件位置精度的检测变得非常简单。全视觉自动识别系统能够高速高精度的完成对带式送料器的工况检测。 相似文献
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《现代表面贴装资讯》2012,(3):20-21
MYDATA新推出的“Agilis柔性送料器”荣获了SMTChina远见奖--装配工具类奖。作为贴片设备中的核心部件之一,送料器的使用效率大大关系到准备和换线时间。MYDATA送料器一直以小巧轻便,利于上料和组装而闻名于业内。10年前,MYDATA向电子行业介绍Agilis送料器后,很快就有了一大批的拥蹇。 相似文献
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Meihua Shen Wilfred Pau Nicolas Gani Jianping Wen Shashank Deshmukh Thorsten Lill Jian Zhang Hanming Wu Guqing Xing 《半导体技术》2004,29(8)
This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration. 相似文献
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White organic light-emitting devices based on fac tris(2- phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene 总被引:1,自引:0,他引:1
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V. 相似文献
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Complete approach to automatic identification and subpixel center location for ellipse feature 总被引:1,自引:0,他引:1
XUE Ting WU Bin SUN Mei YE Sheng-hua 《光电子快报》2008,4(1):51-54
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction. 相似文献
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In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy. 相似文献
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High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center. 相似文献
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This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors. 相似文献
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Credence Systems Corporation 《半导体技术》2004,29(9)
Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V. 相似文献
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YUXiao-hua XIANGYu-qun 《半导体技术》2005,30(2):30-32,37
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB. 相似文献
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It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer (LDV). 相似文献