共查询到20条相似文献,搜索用时 484 毫秒
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2007年,在我国经济快速发展,人民健康意识显著提高、医疗保险政策逐步向好等利好的推动下,中国医疗电子市场持续增长,其规模达到247.3亿元,同比增长17.3%.细分市场中,电子仪器及设备、射频仪器、超声仪器、激光仪器及设备、生化分析仪这五大产品也呈现不同的发展态势.其中,医用电子产品份额仍然稳居首位、医用射频设备增速回升、医用超声波设备前景乐观. 相似文献
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胎儿心率检测是胎儿监护的蕾要环节,它对于实现优生优育具有重要的意义。首先介绍了医用超声多普勒胎儿心率检测系统的整体结构,然后对伪随机码的距离选通原理作了介绍,并用仿真软件systemView对系统及其性能进行了仿真.从而说明系统采用伪随机码比使用连续波更具有优点。 相似文献
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逆合成孔径激光雷达(inverse synthetic aperture ladar,ISAL)发射信号具有超短波长、超大带宽的特点,其回波对目标运动具有极强的敏感性,因而ISAL回波信号特征与常规ISAR回波有很大不同.建立了ISAL回波的精确模型,研究了由于目标运动引起的回波包络展缩、脉内多普勒和脉冲间多普勒效应,并给出了它们的近似方法及约束条件,仿真分析了目标在不同运动参数下回波信号的包络展缩、脉内多普勒效应对ISAL成像的影响,结果表明上述效应会造成图像的散焦,需要在成像中进行相应补偿. 相似文献
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Rob Reeder 《电子设计技术》2008,15(7):133-134,145
上世纪90年代初,便携式电话风靡一时,随着电子技术的长足发展,现今的手机除了可以发送电子邮件和短信,还能拍照、查询股票价格、安排会议;当然,也可以同世界上任何地方的任何人通话。同样在医疗领域中,以前所谓的便携式超声系统曾装载在手推车上以便于拖拽;而今天的医用超声系统也在持续向小型化发展, 相似文献
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利用电磁辐射信号进行雷电源探测和定位是当前雷电研究的重要探测手段,其定位结果的准确性对正确认识闪电的放电机理非常重要。本文通过数学推导建立了多普勒效应在球坐标下的定位影响理论模型;用Matlab软件进行模拟,分析了多普勒效应对阵列接收信号的影响及误差,研究了多普勒效应对运动雷电源定位结果产生的影响。研究结果表明,多普勒效应对于不同类型、不同距离、不同高度的闪电影响程度不同;根据雷电发展的不同阶段,雷电源的运动速度不同,多普勒效应带来的误差也不同,且其带来的误差是不可忽略的。该研究对实现更高时空分辨力的运动雷电源定位结果和雷电的精细化研究具有重要意义。 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 sub-pixel 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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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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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
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正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must 相似文献
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Zhang Xinsheng 《中国通信》2014,(1)
正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta- 相似文献
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正Cloud computing is a novel computing paradigm that utilizes remote cloud resources to achieve a high-performance computation.Cloud provides infrastructure,platform and software as different on-demand services.China has made remarkable progress in cloudbased products and operating system technology.The government,enterprises and research institutions are all active in the development of cloud computing-related projects.Despite the progress,many important problems 相似文献
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