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61.
Comparison of performance between rescaled range analysis and rescaled variance analysis in detecting abrupt dynamic change 下载免费PDF全文
In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis(MCR/S) and moving cutting data-rescaled variance analysis(MC-V/S) is made. The results clearly indicate that the operating efficiency of the MC-R/S algorithm is higher than that of the MC-V/S algorithm. In our numerical test, the computer time consumed by MC-V/S is approximately 25 times that by MC-R/S for an identical window size in artificial data. Except for the difference in operating efficiency, there are no significant differences in performance between MC-R/S and MC-V/S for the abrupt dynamic change detection. MC-R/S and MC-V/S both display some degree of anti-noise ability. However, it is important to consider the influences of strong noise on the detection results of MC-R/S and MC-V/S in practical application processes. 相似文献
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The spatial-temporal evolution of coherent structures(CS) is significant for turbulence control and drag reduction. Among the CS, low and high speed streak structures show typical burst phenomena. The analysis was based on a time series of three-dimensional and three-component(3D-3C) velocity fields of the flat plate turbulent boundary layer(TBL) measured by a Tomographic and Time-resolved PIV(Tomo TRPIV) system. Using multi-resolution wavelet transform and conditional sampling method, we extracted the intrinsic topologies and found that the streak structures appear in bar-like patterns. Furthermore, we seized locations and velocity information of transient CS, and then calculated the propagation velocity of CS based on spatial-temporal cross-correlation scanning. This laid a foundation for further studies on relevant dynamics properties. 相似文献
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Sulfur and Nitrogen Codoped Carbon Tubes as Bifunctional Metal‐Free Electrocatalysts for Oxygen Reduction and Hydrogen Evolution in Acidic Media 下载免费PDF全文
Tao Sun Prof. Qiang Wu Yufei Jiang Zhiqi Zhang Lingyu Du Prof. Lijun Yang Prof. Xizhang Wang Prof. Zheng Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10261-10261
Invited for the cover of this issue is the group of Qiang Wu and Zheng Hu at Nanjing University. The image depicts sulfur and nitrogen codoped carbon tubes as bifunctional metal‐free electrocatalysts for oxygen reduction and hydrogen evolution in acidic media. Read the full text of the article at 10.1002/chem.201601535 . 相似文献
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Post‐Synthetic Polymerization of UiO‐66‐NH2 Nanoparticles and Polyurethane Oligomer toward Stand‐Alone Membranes for Dye Removal and Separation 下载免费PDF全文
Dr. Bing‐Jian Yao Wei‐Ling Jiang Dr. Ying Dong Zhi‐Xian Liu Prof. Dr. Yu‐Bin Dong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10565-10571
Metal–organic frameworks (MOFs) are widely used as porous materials in the fields of adsorption and separation. However, their practical application is largely hindered by limitations to their processability. Herein, new UiO‐66‐Urea‐based flexible membranes with MOF loadings of 50 ( 1 ), 60 ( 2 ), and 70 wt % ( 3 ) were designed and prepared by post‐synthetic polymerization of UiO‐66‐NH2 nanoparticles and a polyurethane oligomer under mild conditions. The adsorption behavior of membrane 3 towards four hydrophilic dyes, namely, eosin Y (EY), rhodamine B (RB), malachite green (MG), and methylene blue (MB), in aqueous solution was studied in detail. It exhibits strong adsorption of EY and RB but weak adsorption of MG and MB in aqueous solution. Owing to the selective adsorption of these hydrophilic dyes, membrane 3 can remove EY and RB from aqueous solution and completely separate EY/MB, RB/MG, and RB/MB mixtures in aqueous solution. In addition, the membrane is uniformly textured, easily handled, and can be reused for dye adsorption and separation. 相似文献
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