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591.
Yuri Murakami Hiroyuki Manabe Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama 《Optical Review》2004,11(2):76-81
Recently, multispectral images have been utilized for high fidelity color reproduction through visual telecommunication systems and its compression schemes have been required. However multispectral image coding considering color degradation has not been established. This article presents a comparison of four spectral transforms presented before to find out which transform is more suitable to a spectral decorrelation scheme in transform coding of multispectral images. Transforms dealt with in this paper are Karhunen-Loeve transform (KLT), weighted KLT (WKLT), one mode analysis (OMA) and a transform realizing compatibility to the conventional color systems, latter three of which are designed to represent spectral reflectance functions with small number of coefficients having small colorimetric errors. Through the theoretical and experimental comparisons, it is found that WKLT and OMA reduced colorimetric error compared to the others, where OMA is suitable when the rendering illuminations in the color reproduction can be assumed in advance and WKLT is applicable to other situations. 相似文献
592.
Masanori Mitsui Yuri Murakami Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama 《Optical Review》2005,12(2):69-75
We propose a new method for the color enhancement of multispectral image in the visible wavelength region. The purpose of the proposed method is to explore the weak features contained in a specific wavelength by discounting the major color distribution. Such examination will be valuable in visual inspection applications, for example, a medical examination using color image to find a small spectral change of an abnormal part. In this method, Karhunen-Loeve (KL) transform is applied to multispectral data, and specific wavelength components of only high-order KL coefficients are amplified while low-order coefficients are not changed to retain the major color distribution. In the experiment, this method was applied to multispectral images: a printed test image and a human skin image of a bruised arm were captured by a 16-band multispectral camera. The resultant images were compared with the images obtained by saturation enhancement and that obtained by applying the proposed method to the 3-band image. The method successfully visualized the features, which are almost invisible in natural color images, with less change in background color than saturation enhancement. 相似文献
593.
Md. Arifur Rahim Mattias Björnmalm Tomoya Suma Matthew Faria Yi Ju Dr. Kristian Kempe Dr. Markus Müllner Dr. Hirotaka Ejima Dr. Anthony D. Stickland Prof. Frank Caruso 《Angewandte Chemie (International ed. in English)》2016,55(44):13803-13807
Materials assembled by coordination interactions between naturally abundant polyphenols and metals are of interest for a wide range of applications, including crystallization, catalysis, and drug delivery. Such an interest has led to the development of thin films with tunable, dynamic properties, however, creating bulk materials remains a challenge. Reported here is a class of metallogels formed by direct gelation between inexpensive, naturally abundant tannic acid and group(IV) metal ions. The metallogels exhibit diverse properties, including self‐healing and transparency, and can be doped with various materials by in situ co‐gelation. The robustness and flexibility, combined with the ease, low cost, and scalability of the coordination‐driven assembly process make these metallogels potential candidates for chemical, biomedical, and environmental applications. 相似文献
594.
Keiichi Irifune Dr. Ken Yamazaki Dr. Takayuki Nakamuro Prof. Dr. Masahiro Murakami Prof. Dr. Tomoya Miura 《Angewandte Chemie (International ed. in English)》2023,62(33):e202307826
A ligand-controlled regiodivergence in Ni-catalyzed rearrangement of vinylcyclopropanes to 1,4- or 1,5-disubstituted cyclopentenes is reported. The 1,4- or 1,5-disubstituted cyclopentene is selectively obtained depending on the choice of ligands. Detailed kinetic studies and density functional theory calculations on the catalytic cycle revealed that the product selectivity is determined at the reductive elimination step from the six-membered η1-allyl intermediate. 相似文献
595.
Fukuchi M Takegoshi K Ishizuka T Furuta H 《Magnetic resonance in chemistry : MRC》2007,45(Z1):S56-S60
Using (15)N high-resolution solid-state NMR and X-ray diffraction, the structure of N-confused porphyrin (NCP) in the solid state was studied. A 1D (15)N magic angle spinning (MAS) experiment and a 2D dipolar assisted rotational resonance (DARR) (15)N-(15)N spin exchange experiment of N-confused tetratolylporphyrin (Tol) crystallized from CH(2)Cl(2)/hexane indicate that Tol is the inner 3H-type tautomer and has two magnetically different molecules in the unit cell. Further, a FSLG-2 & 4macr; 2 (1)H-(15)N dipolar recoupling NMR measurement indicates no fast ring flipping motion which is consistent with the planar structure in the X-ray analysis. The planarity of Tol is ascribed to crystal packing enforced by pi-pi stacking and CH-pi interactions. 相似文献
596.
Assessment of macrocyclic triamine ligands as synthons for organometallic 99mTc radiopharmaceuticals
Suzuki K Shimmura N Thipyapong K Uehara T Akizawa H Arano Y 《Inorganic chemistry》2008,47(7):2593-2600
In a search of coordination molecules suitable to the fac-{(99m)Tc(CO)3}(+) core as a synthon for (99m)Tc-radiopharmaceuticals, nonradioactive rhenium complexes of two macrocyclic triamine compounds with different chelate ring structures, 1,4,7-triazacyclononane (9N3) and 1,5,9-triazacyclododecane (12N3), were synthesized and characterized. (99m)Tc-labeled 9N3 and 12N3 compounds were also prepared using [(99m)Tc(OH 2)3(CO)3](+) and were characterized by both in vitro and in vivo studies. 9N3 produced a single rhenium complex, whereas 12N3 generated two major complexes. The crystallographic data and infrared absorption wavenumber assigned to the C-O stretch suggested that the coordination geometry of 9N3 would be more suitable to fac-{Re(CO)3}(+) than that of 12N3. In contrast, both 9N3 and 12N3 provided a single (99m)Tc-labeled compound. However (99m)Tc-labeled 9N3 exhibited higher stability than (99m)Tc-labeled 12N3 in rat plasma and in the presence of histidine at an elevated temperature. In biodistribution studies, both (99m)Tc-labeled compounds did not show any specific accumulation of radioactivity in any organs except for the excretory organs such as the liver and kidney. These findings showed that 9N3 would constitute a macrocyclic chelating molecule of choice to prepare (99m)Tc radiopharmaceuticals using a fac-{(99m)Tc(CO)3}(+) core. 相似文献
597.
Ono A Cao S Togashi H Tashiro M Fujimoto T Machinami T Oda S Miyake Y Okamoto I Tanaka Y 《Chemical communications (Cambridge, England)》2008,(39):4825-4827
Very specific binding of the Ag(i) ion unexpectedly stabilized DNA duplexes containing the naturally occurring cytosine-cytosine (C-C) mismatch-base pair; because the C-C pair selectively binds to the Ag(i) ion, we developed a DNA-based Ag(i) sensor that employed an oligodeoxyribonucleotide containing C-C pairs used for Ag(i) binding sites. 相似文献
598.
Anti-SN2' mode of allylation of the monoester of 4-cyclopentene-1,3-diol with aryl and alkenyl anions was achieved, for the first time, with the MeOCH2CO2- group as a leaving group to which R-ZnBr and CuCl (as a catalyst) were best fitted. The aryl groups successfully installed were Ph, o- and p-MeC6H4, o-MOMOC6H4, o-MeOC6H4, and p-F-C6H4, while cis and trans alkenyl groups were attached with retention of the olefinic stereochemistries. 相似文献
599.
2-alkynylaryl isocyanates reacted with bis(pinacolato)diboron in the presence of a cationic rhodium(I) catalyst to produce borylated 3-alkylideneoxindoles stereoselectively. The carbon-boron linkage formed was further transformed via reactions such as a cross-coupling and a halogenation reaction. 相似文献
600.
[structure: see text]. A bromocoumarin scaffold (1) was reacted with various boronic acid derivatives (2a-l) to afford a library of 6-arylcoumarins (3a-l). This library was found to contain candidate fluorescent sensors for peptidase activity and for nitric oxide. 相似文献