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1.
Iridium‐ and Osmium‐decorated Reduced Graphenes as Promising Catalysts for Hydrogen Evolution 下载免费PDF全文
Chee Shan Lim Prof. Zdeněk Sofer Rou Jun Toh Alex Yong Sheng Eng Jan Luxa Prof. Martin Pumera 《Chemphyschem》2015,16(9):1898-1905
Renewable energy sources are highly sought after as a result of numerous worldwide problems concerning the environment and the shortage of energy. Currently, the focus in the field is on the development of catalysts that are able to provide water splitting catalysis and energy storage for the hydrogen evolution reaction (HER). While platinum is an excellent material for HER catalysis, it is costly and rare. In this work, we investigated the electrocatalytic abilities of various graphene–metal hybrids to replace platinum for the HER. The graphene materials were doped with 4f metals, namely, iridium, osmium, platinum and rhenium, as well as 3d metals, namely, cobalt, iron and manganese. We discovered that a few hybrids, in particular iridium‐ and osmium‐doped graphenes, have the potential to become competent electrocatalysts owing to their low costs and—more importantly—to their promising electrochemical performances towards the HER. One of the more noteworthy observations of this work is the superiority of these two hybrids over MoS2, a well‐known electrocatalyst for the HER. 相似文献
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This paper presents a novel and efficient locally adaptive denoising method based on clustering of pixels into regions of similar geometric and radiometric structures. Clustering is performed by adaptively segmenting pixels in the local kernel based on their augmented variational series. Then, noise pixels are restored by selectively considering the radiometric and spatial properties of every pixel in the formed clusters. The proposed method is exceedingly robust in conveying reliable local structural information even in the presence of noise. As a result, the proposed method substantially outperforms other state-of-the-art methods in terms of image restoration and computational cost. We support our claims with ample simulated and real data experiments. The relatively fast runtime from extensive simulations also suggests that the proposed method is suitable for a variety of image-based products ?? either embedded in image capturing devices or applied as image enhancement software. 相似文献
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应用E-GOS(E-Gamma Over Spin)曲线方法研究了A≈110质量区奇A核结构随角动量增加的演化, 发现随着角动量的增加原子核的激发特性从振动逐渐演化为转动。 The E-GOS(E-Gamma Over Spin)curves were used to investigate the structure evolution in the odd A nuclei around A≈110 as a function of spin. The result shows that there is a clear transition from vibration to rotation while increasing spin. 相似文献
6.
H. B. Zhou X. H. Zhou Y. H. Zhang Y. Zheng M. L. Liu N. T. Zhang L. Chen S. T. Wang G. S. Li H. X. Wang B. Ding X. G. Lei Y. X. Guo G. X. Dong F. R. Xu M. Oshima Y. Toh M. Koizumi A. Osa Y. Hatsukawa 《The European Physical Journal A - Hadrons and Nuclei》2011,47(9):1-7
High-spin states in 101Pd have been investigated by means of in-beam γ-ray spectroscopic techniques via the 76Ge(28Si, 3n) reaction at beam energies of 85 and 95 MeV. The previously known d 5/2 and 1/2?[550] bands were extended to higher spins, and the unfavored signature branch of the 1/2?[550] band was built. The band crossings observed experimentally are explained by the alignment of g 9/2 protons. The band properties in 101Pd are compared with those in the neighboring nuclei and are discussed within the framework of the cranked shell model (CSM). 相似文献
7.
Fang YongDe Zhang YuHu Oshima M. Toh Y. Xu FuRong Shi Yue Zhou XiaoHong Liu MinLiang Guo YingXiang Koizumi M. Kimura A. Hatsukawa Y. Morikawa T. Nakamura M. Sugaware M. Kusakari H. 《中国科学:物理学 力学 天文学(英文版)》2011,54(1):98-102
A new rotational band has been identified and assigned to 188Au for the first time using the 173Yb(19F,4nγ) reaction at the beam energies of 86 and 90 MeV. This band is proposed to be built on the πh 9/2 ⊗ νi 13/2 configuration by comparing the band properties with known bands in neighboring nuclei. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around 188Au for the ηh 9/2 ⊗ νi 13/2 bands in odd-odd Au isotopes on the basis of total Routhian surface (TRS) calculations.
相似文献8.
We consider a class of unconstrained nonsmooth convex optimization problems, in which the objective function is the sum of
a convex smooth function on an open subset of matrices and a separable convex function on a set of matrices. This problem
includes the covariance selection problem that can be expressed as an ℓ
1-penalized maximum likelihood estimation problem. In this paper, we propose a block coordinate gradient descent method (abbreviated
as BCGD) for solving this class of nonsmooth separable problems with the coordinate block chosen by a Gauss-Seidel rule. The
method is simple, highly parallelizable, and suited for large-scale problems. We establish global convergence and, under a
local Lipschizian error bound assumption, linear rate of convergence for this method. For the covariance selection problem,
the method can terminate in O(n3/e){O(n^3/\epsilon)} iterations with an e{\epsilon}-optimal solution. We compare the performance of the BCGD method with the first-order methods proposed by Lu (SIAM J Optim
19:1807–1827, 2009; SIAM J Matrix Anal Appl 31:2000–2016, 2010) for solving the covariance selection problem on randomly generated instances. Our numerical experience suggests that the
BCGD method can be efficient for large-scale covariance selection problems with constraints. 相似文献
9.
Yew Hoong Leong Jaguthsing Dindyal Tin Lam Toh Khiok Seng Quek Eng Guan Tay Sieu Tee Lou 《ZDM》2011,43(6-7):819-831
Problem solving is at the heart of the Singapore Mathematics curriculum. However, it remains a challenge for teachers to realise this curricular goal in practice. Here, we review the efforts of Singapore mathematics teacher educators in incorporating problem-solving (teaching) competency in teacher education and PD programmes. We discuss conceptual and practical issues, actions taken and changes made in building teachers?? capacity to enact a problem-solving curriculum in a school-based design experiment project. In the project, teachers learnt problem solving, observed and then carried out lessons, using the ??Mathematics Practical????akin to the science practical??as key to instruction and assessment. 相似文献
10.
Julita K. Grzeskowiak Anne Tscheliessnig Poh Choo Toh Janet Chusainow Yih Yean Lee Niki Wong Alois Jungbauer 《Journal of chromatography. A》2009,1216(24):4902-4912
Although Staphylococcus Protein A (SpA) affinity chromatography is the state of the art capture step for antibody purification, non-affinity methods are more economical. We used two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) to evaluate the purification of a recombinant IgG1 antibody from cultured cells, with two different processes: (1) SpA capture followed by cation-exchange chromatography (CEX); and (2) CEX capture, followed by anion exchanger, then hydrophobic interaction chromatography. Efficiencies were similar in sodium dodecylsulphate polyacrylamide gel electrophoresis and size-exclusion chromatography; however, 2-D DIGE revealed higher efficiency with SpA than with CEX capture. Thus, 2-D DIGE is a valuable tool for downstream process development. 相似文献