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排序方式: 共有139条查询结果,搜索用时 15 毫秒
1.
Isa Illyas Md Sharif Sharifah Norain Mohd Hashim Norhayati Ghani Sulaiman Ab 《Ionics》2015,21(10):2949-2958
Ionics - A mercury(II) sensor was developed by using single-walled carbon nanotube (SWCNT) paste electrode modified with layered double Zn/Al hydroxide-3(4-methoxyphenyl)propionate nanocomposite... 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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This paper presents the optimized K-means (OKM) algorithm that can homogenously segment an image into regions of interest with the capability of avoiding the dead centre and trapped centre at local minima phenomena. Despite the fact that the previous improvements of the conventional K-means (KM) algorithm could significantly reduce or avoid the former problem, the latter problem could only be avoided by those algorithms, if an appropriate initial value is assigned to all clusters. In this study the modification on the hard membership concept as employed by the conventional KM algorithm is considered. As the process of a pixel is assigned to its associate cluster, if the pixel has equal distance to two or more adjacent cluster centres, the pixel will be assigned to the cluster with null (e. g., no members) or to the cluster with a lower fitness value. The qualitative and quantitative analyses have been performed to investigate the robustness of the proposed algorithm. It is concluded that from the experimental results, the new approach is effective to avoid dead centre and trapped centre at local minima which leads to producing better and more homogenous segmented images. 相似文献
6.
Nívia Maria Melo Coelho Edmar Isaías de Melo Hélen Cristine de Rezende Ana Graci Brito-Madurro João Marcos Madurro 《Journal of Solid State Electrochemistry》2012,16(3):945-951
In this work, carbon electrodes modified with aminophenols were developed for the production of pesticides biosensors based
on acetylcholinesterase. The polymers were potentiodynamically deposited on a graphite electrode surface by the oxidation
of monomers, 2-aminophenol, 3-aminophenol and 4-aminophenol. The electrochemical behaviour and surface analysis of the electrodes
modified by polyaminophenols non-immobilized and immobilized on acetylcholinesterase were studied by cyclic voltammetry, electrochemical
impedance spectroscopy and atomic force microscopy. Roughness values obtained for graphite electrodes modified with poly(4-aminophenol)
and poly(4-aminophenol)/acetylcholinesterase were 174 and 86 nm, respectively. The acetylcholinesterase enzyme was immobilized
on a graphite and a graphite modified with poly(4-aminophenol), and these electrodes were coupled in the flow system. Potentiometric
response due to hydrogen ions generated by an enzymatic system in the presence of acetylcholine chloride substrate was evaluated.
The results showed that the graphite/poly(4-aminhophenol) sensor presents high sensitivity to hydrogen ions when compared
with other graphite/polyaminophenols sensors. The biosensor coupled in a continuous flow system was employed for the detection
of dichlorvos. The detection and quantification limits were 0.8 and 2.4 μmol L−1 dichlorvos, respectively. This sensor reveals an efficient and promising material for biomolecules immobilization. 相似文献
7.
Azmi Mohamed Argo Khoirul Anas Suriani Abu Bakar Azira Abd. Aziz Masanobu Sagisaka Paul Brown Julian Eastoe Azlan Kamari Norhayati Hashim Illyas Md Isa 《Colloid and polymer science》2014,292(11):3013-3023
The performance of single-, double- and triple-chain anionic sulphosuccinate surfactants for dispersing multiwall carbon nanotubes (MWNCTs) in natural rubber latex (NR-latex) was studied using a range of techniques, including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Raman spectroscopy. The conductivities of the nanocomposites were also investigated using four-point probe measurements. Here, MWCNTs were efficiently dispersed in NR-latex with the aid of hyperbranched tri-chain sulphosuccinate anionic surfactants, specifically sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate (TC14). This paper highlights that TC14 performs much better than that of the commercially available surfactant sodium dodecyl sulphate (SDS), demonstrating how careful consideration of surfactant architecture leads to improved dispersibility of MWCNTs in NR-latex. The results should be of significant interest for improving nanowiring applications suitable for aerospace-based technology. 相似文献
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Heterocyclic 4-sulfonyl-2-pyridones represent useful scaffolds for drug discovery, and are also versatile synthetic building blocks. Herein, we describe a novel and efficient synthesis of this heterocyclic ring system utilizing an acid-mediated cyclo-condensation reaction. This synthetic method affords convenient access to structurally diverse N-substituted 4-sulfonyl-2-pyridones in moderate to good yields. 相似文献
9.
Isa Nishiyama 《Chemical record (New York, N.Y.)》2009,9(6):340-355
In this article, liquid crystal phases possessing a helical molecular assembly, including frustrated three dimensional (3D) structures, are overviewed. Then, the chirality‐originated superstructures in liquid crystals studied by the author are reviewed. The importance of the concept of “pre‐organization” is highlighted, thus, molecular design producing a strong chiral effect has been proposed. Dichiral twin materials have been prepared systematically based on this concept, and correlation between molecular architectures and resulting frustrated liquid crustal phases, such as smectic blue, cubic, tetragonal smectic Q, and sponge phases, has been investigated. An electrically induced anisotropic birefringent structure in the chiral isotropic phase and a photoinduced 3D‐3D phase transition in the smectic Q phase are introduced as possible application on the basis of the frustrated chiral 3D structured liquid crystal phases. A new type of chiral effect inducing the structural anisotropy in the 3D cubic structure of soft material is also described. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 340–355; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900029 相似文献
10.
The Compressibility of pH‐Sensitive Microgels at the Oil–Water Interface: Higher Charge Leads to Less Repulsion 下载免费PDF全文
Dipl.‐Chem. Karen Geisel Prof. Dr. Lucio Isa Prof. Dr. Walter Richtering 《Angewandte Chemie (International ed. in English)》2014,53(19):4905-4909
pH‐responsive microgels are unique stabilizers for stimuli‐sensitive emulsions that can be broken on demand by changing the pH value. However, recent experiments have indicated that electrostatic interactions play a different role to that in conventional Pickering emulsions. The influence of charges on the interactions between microgels at the oil–water interface is now described. Compression isotherms of microgels with different charge density and architecture were determined in a Langmuir trough, and counter‐intuitive results were obtained: Charged microgels can be compressed more easily than uncharged microgels. The compressibility of microgels is thus not determined by direct Coulomb repulsion. Instead, the different swelling of the microgels in the charged and the uncharged states is proposed to be the key parameter. 相似文献