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81.
Thang Viet Pham Jeong‐Gil Kim Jae Young Jung Jun Hee Kim Hyunjin Cho Tae Hoon Seo Hunsu Lee Nam Dong Kim Myung Jong Kim 《Advanced functional materials》2019,29(48)
The lack of cost effective, industrial‐scale production methods hinders the widespread applications of graphene materials. In spite of its applicability in the mass production of graphene flakes, arc discharge has not received considerable attention because of its inability to control the synthesis and heteroatom doping. In this study, a facile approach is proposed for improving doping efficiency in N‐doped graphene synthesis through arc discharge by utilizing anodic carbon fillers. Compared to the N‐doped graphene (1–1.5% N) synthesized via the arc process according to previous literature, the resulting graphene flakes show a remarkably increased doping level (≈3.5% N) with noticeable graphitic N enrichment, which is rarely achieved by the conventional process, while simultaneously retaining high turbostratic crystallinity. The electrolyte ion storage of synthesized materials is examined in which synthesized N‐doped graphene material exhibits a remarkable area normalized capacitance of 63 µF cm?2. The surprisingly high areal capacitance, which is superior to that of most carbon materials, is attributed to the synergistic effect of extrinsic pseudocapacitance, high crystallinity, and abundance of exposed graphene edges. These results highlight the great potentials of N‐doped graphene flakes produced by arc discharge in graphene‐based supercapacitors, along with well‐studied active exfoliated graphene and reduced graphene oxide. 相似文献
82.
测向误差的减小一直以来都是无线电测向精度提高的一个难点,对于不同的测向体制所采用的减小测向误差的方法都不尽相同。本文主要介绍的是相关干涉仪测向体制的基本原理以及通过内插法的应用来减小测向误差的方法。 相似文献
83.
为快速准确检测薄零件几何量精度,提出了一种基于机器视觉的检测方法。根据具体的视场和精度要求,完成电荷耦合元件(CCD)传感器、镜头、光源等选型与硬件系统设计。开发了软件系统,采用双三次插值法细分图像后提取亚像素边缘,变权重最小二乘法拟合出零件轮廓的圆弧和直线,自动计算零件的圆度误差,中心距尺寸误差,并判断其是否合格。通过齿轮泵中间体零件的检测结果表明,本系统能快速准确检测中高精度(IT7级)薄零件的几何量精度,满足实际应用的需求。 相似文献
84.
B. Marion S. Rummel A. Anderberg 《Progress in Photovoltaics: Research and Applications》2004,12(8):593-607
By means of bilinear interpolation and four reference current–voltage (I–V) curves, an I–V curve of a photovoltaic (PV) module is translated to desired conditions of irradiance and PV module temperature. The four reference I–V curves are measured at two irradiance and two PV module temperature levels and contain all the essential PV module characteristic information for performing the bilinear interpolation. The interpolation is performed first with respect to open‐circuit voltage to account for PV module temperature, and second with respect to short‐circuit current to account for irradiance. The translation results over a wide range of irradiances and PV module temperatures agree closely with measured values for a group of PV modules representing seven different technologies. Root‐mean‐square errors were 1·5% or less for the I–V curve parameters of maximum power, voltage at maximum power, current at maximum power, short‐circuit current, and open‐circuit voltage. The translation is applicable for determining the performance of a PV module for a specified test condition, or for PV system performance modeling. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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定量分析了阵列孔径、干扰信号带宽、通道幅相误差以及A/D变换器的量化噪声对大型稀布圆形阵列天线干扰对消效果的影响,介绍了稀布阵综合脉冲孔径雷达(SIAR)采用抽头延迟线以提高干扰对消性能的方法,并给出了数值计算与计算机模拟结果。 相似文献
89.
Dimitrios Tzovaras Nikos Grammalidis Michael G. Strintzis 《Signal Processing: Image Communication》1998,11(3):205-230
In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods. 相似文献
90.
Elvi Räisänen-Ruotsalainen Timo Rahkonen Juha Kostamovaara 《Analog Integrated Circuits and Signal Processing》1998,15(1):49-57
The main features of two time-to-digital convertersbased on interpolation are presented, together with some measurementresults. The first converter is based on digital delay line interpolatorsand has been implemented in a 1.2 µm CMOS process.It has a single-shot resolution of 1 ns (-value)and a nonlinearity less than ±50 ps in the measurementrange 5 to 500 ns. The power consumption of the circuit is 15mW. The second time digitizer has analog interpolators basedon time-to-voltage conversion and has been implemented in a 1.2 µm BiCMOS process. It has a single-shot resolutionof 50 ps and a nonlinearity less than 150 ps in the measurementrange 1 to 300 ns. The power consumption of this circuit is 200mW. 相似文献