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921.
The rank information of samples is widely utilized in nonlinear signal processing algorithms. Recently developed fuzzy transformation theory introduces the concept of fuzzy ranks, which incorporates sample spread (or sample diversity) information into the sample ranking framework. Thus, the fuzzy rank reflects a sample's rank, as well as its similarity to the other sample (namely, joint rank order and spread), and can be utilized to improve the performance of the conventional rank-order-based filters. In this paper, the well-known lower-upper-middle (LUM) filters are generalized utilizing the fuzzy ranks, yielding the class of fuzzy rank LUM (F-LUM) filters. Statistical and deterministic properties of the F-LUM filters are derived, showing that the F-LUM smoothers have similar impulsive noise removal capability to the LUM smoothers, while preserving the image details better. The F-LUM sharpeners are capable of enhancing strong edges while simultaneously preserving small variations. The performance of the F-LUM filters are evaluated for the problems of image impulsive noise removal, sharpening and edge-detection preprocessing. The experimental results show that the F-LUM smoothers can achieve a better tradeoff between noise removal and detail preservation than the LUM smoothers. The F-LUM sharpeners are capable of sharpening the image edges without amplifying the noise or distorting the fine details. The joint smoothing and sharpening operation of the general F-LUM filters also showed superiority in edge detection preprocessing application. In conclusion, the simplicity and versatility of the F-LUM filters and their advantages over the conventional LUM filters are desirable in many practical applications. This also shows that utilizing fuzzy ranks in filter generalization is a promising methodology. 相似文献
922.
简要论述了黑龙江省6大本地网新建长途局的比要性,介绍了长途局兼做智能网业务接入SSP及信令转接STP功能、长途中继电路物分配原则、网同步实施方法及信令组织的方案和原则等。 相似文献
923.
The near-threshold highly bound states of all three stable isotopic
variants of molecular hydrogen have been studied. Numerous
perturbations and unexpected transitions are observed as far as
1cm\sj{-1} just below the second dissociation threshold. This
complex structure may arise from a combination of nonadiabatic
coupling between B, B', C electronic states, perturbations due to
fine and hyperfine interactions, and strong shape resonances. The
perturbed near-threshold states and vibrational continuum exhibit
finegrained structure, differing greatly between isotopes because of
varying nonadiabatic coupling. 相似文献
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928.
Nie W Luo JG Wang XB Yin H Sun HB Yao HQ Kong LY 《Chemical & pharmaceutical bulletin》2011,59(8):1051-1056
A series of α-glucosidase inhibitors with the oleanolic acid core and different cinnamic amide ligands were designed and synthesized. Their preliminary structure-activity relationships were analyzed. In general, the compounds with 3,28-disubstituted oleanolic acid exhibited stronger activity than those 28-monosubstituted analogues, and variation of cinnamic amide substitution significantly affected α-glucosidase inhibition activities. Most of the compounds showed potent inhibitory activity against α-glucosidase with much greater efficacy than a typical α-glucosidase inhibitor, acarbose. 相似文献
929.
A low-energy hydrogen bombardment method, without using any chemical additives, has been designed for fine tuning both physical and chemical properties of molecular thin films through selectively cleaving C-H bonds and keeping other bonds intact. In the hydrogen bombardment process, carbon radicals are generated during collisions between C-H bonds and hydrogen molecules carrying ~10 eV kinetic energy. These carbon radicals induce cross-linking of neighboring molecular chains. In this work, we focus on the effect of hydrogen bombardment on dotriacontane (C(32)H(66)) thin films as growing on native SiO(2) surfaces. After the hydrogen bombardment, XPS results indirectly explain that cross-linking has occurred among C(32)H(66) molecules, where the major chemical elements have been preserved even though the bombarded thin film is washed by organic solution such as hexane. AFM results show the height of the perpendicular phase in the thin film decreases due to the bombardment. Intriguingly, Young's modulus of the bombarded thin films can be increased up to ~6.5 GPa, about five times of elasticity of the virgin films. The surface roughness of the thin films can be kept as smooth as the virgin film surface after thorough bombardment. Therefore, the hydrogen bombardment method shows a great potential in the modification of morphological, mechanical, and tribological properties of organic thin films for a broad range of applications, especially in an aggressive environment. 相似文献
930.
Miao Yang Lifu Liao Guangliang Zhang Bo He Xilin Xiao Yingwu Lin Changming Nie 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(2):1393-1399
A new wireless sensing method for the detection of uranium in water samples has been reported in this paper. The method is based on a sandwich-type detection strategy. Salophen, a tetradentate ligand of uranyl ion, was immobilized on the surface of the polyurethane-protected magnetoelastic sensor as receptor for the capture of uranyl ion. The phosphorylated polyvinyl alcohol coated magnetic Fe3O4 nanoparticles were used as signal-amplifying tags of uranyl ion. In a procedure of determining uranium, firstly uranyl ion in sample solution was captured on the sensor surface. Then the captured uranyl bound the nanoparticle through its coordination with the phosphate group. The amount of uranium was detected through the measure of the resonance frequency shift caused by the enhanced mass loading on the sensor surface. A linear range was found to be 0.2–20.0 μg/L under optimal conditions with a detection limit of 0.11 μg/L. The method has been applied to determine uranium in environmental water samples with the relative standard deviations of 2.1–3.6 % and the recoveries of 98.0–101.5 %. The present technique is one of the most suitable techniques for assay of uranium at trace level in environmental water samples collected from different sources. 相似文献