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891.
We report our recent work on a hadronic molecule state of the K(K)N system with I=1/2 and J~P=1/2~+. We assume that the A(1405) resonance and the scalar mesons, f_0(980), a_0(980), are reproduced as quasi-bound states of (K)N and K(K), respectively. Performing non-relativistic three-body calculations with a variational method for this system, we find a quasibound state of the K(K)N system around 1910 MeV below the three-body breakup threshold. This state corresponds to a new baryon resonance of N~* with J~P = 1/2~+. We find also that this resonance has the cluster structure of the two-body bound states keeping their properties as in the isolated two-particle systems. We also briefly discuss another hadronic molecular state composed by two (K) and one (N), which corresponds to a Ξ~* resonance. 相似文献
892.
Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) were applied to investigate the segregation of aluminum atoms on a Cu-9 at.% Al(1 1 1) surface. We observed that the Al concentration in the top layer ranged between about 9 and 36 at.% after the sample we used was annealed at different temperatures. The phenomenon of Al atoms segregating on the surfaces was explained well by considering the diffusion length of Al atoms in bulk Cu. LEED measurements showed that R30° structures grew as the concentration of Al atoms increased. The segregation phenomena on surfaces resulted in a stable two-dimensional Cu67Al33 alloy phase in the top layer. 相似文献
893.
A trace amount (0.5 mol%) of CuO-doped 40Li2O–32Nb2O5–28SiO2 glass (mol%) exhibits the formation of copper metal layers at the glass surface by annealing at temperatures (530 °C) below the glass transition temperature (544 °C) in the reduced atmosphere of 7% H2–93%Ar. The coordination state of copper ions is examined from optical absorption and Fourier transform infrared (FT-IR) spectrum measurements, indicating the formation of Si–OH and Si–H bonds due to the diffusion of hydrogen into the inside of the glass and the reduction of Cu+ and Cu2+ ions. The mechanism of the formation of copper metals at the surface is proposed, in which the key points are the reduction of Cu2+ to Cu+ ions due to the hydrogen and the migration of Cu+ ions in the interior of the glass to the surface. The first finding on copper metal layers at the glass surface might have a potential for practical applications such as electrodes in glass. 相似文献
894.
We investigate hadronic molecule states of $K \bar K N$ and $\bar K \bar K N$ systems with I?=?1/2 and J P ?=?1/2?+?, assuming that Λ(1405) and the scalar mesons, f 0(980), a 0(980), are reproduced as quasi-bound states of $\bar KN$ and $K \bar K$ . Performing non-relativistic three-body calculations for these systems, we find weakly bound states for $K \bar K N$ and $\bar K \bar K N$ around 1900 MeV, which correspond to new baryon resonances of N * and Ξ * with J P ?=?1/2?+?. We find that these resonances have cluster structure of the two-body bound state keeping its properties as in the isolated two-particle system. 相似文献
895.
The separation methods for proteins with high resolution and sensitivity are absolutely important in the field of biological sciences. Capillary sieving electrophoresis (CSE) is an excellent separation technique for DNA and proteins with high resolution, while LIF permits the most sensitive detection in CSE. Therefore, proteins have to be labeled with fluorescent or fluorogenic reagent to produce fluorescent derivatives. Both precolumn and oncolumn derivatization have been employed for the labeling of proteins in CSE. However, there is no report on the postcolumn derivatization due to the limitation in the use of a standard migration buffer, despite it being a promising method for sensitive detection of proteins. Here, we show a novel postcolumn derivatization method for protein separation by CSE, using a tertiary amine as a buffer component in the running buffer. Tris, which is commonly used as a base in CSE separation buffers, was substituted by tertiary amines, 2‐(diethylamino)ethanol and triethanolamine. A buffer solution containing 2‐(diethylamino)ethanol or triethanolamine can be used for the CSE separation followed by the postcolumn derivatization of proteins, since both reagents are unreactive toward a fluorogenic labeling reagent, naphthalene‐2,3‐dicarbaldehyde. Thus, LIF detection using the postcolumn derivatization permits significant reduction in the LOD (by a factor of 2.4–28) of proteins, compared with conventional absorbance detection. 相似文献
896.
Keiichi Hirose 《Journal of solid state chemistry》2009,182(7):1624-1630
Ternary rare earth oxides EuLn2O4 (Ln=Gd, Dy-Lu) were prepared. They crystallized in an orthorhombic CaFe2O4-type structure with space group Pnma. 151Eu Mössbauer spectroscopic measurements show that the Eu ions are in the divalent state. All these compounds show an antiferromagnetic transition at 4.2-6.3 K. From the positive Weiss constant and the saturation of magnetization for EuLu2O4, it is considered that ferromagnetic chains of Eu2+ are aligned along the b-axis of the orthorhombic unit cell, with neighboring Eu2+ chains antiparallel. When Ln=Gd-Tm, ferromagnetically aligned Eu2+ ions interact with the Ln3+ ions, which would overcome the magnetic frustration of triangularly aligned Ln3+ ions and the EuLn2O4 compounds show a simple antiferromagnetic behavior. 相似文献
897.
Jae-hoon Choi Hiroshi Okumura Kaoru Nagai Daisuke Hashizume Hirokazu Kawagishi 《Tetrahedron》2009,65(1):221-6653
Two novel compounds, 3-(hydroxymethyl)-4-methylfuran-2(5H)-one (1) and (3R,4S,1′R)-3-(1′-hydroxyethyl)-4-methyldihydrofuran-2(3H)-one (2), were isolated along with two known ones (3 and 4) from an edible mushroom Mycoleptodonoides aitchisonii. The structures of 1-4 were determined by the interpretation of spectroscopic data. Compounds 1-4 showed protective activity against endoplasmic reticulum (ER) stress-dependent cell death. 相似文献
898.
Yanying Zhang Koichi Mitsudo Shunzo Suematsu Daisuke Horii Kenji Tamamitsu 《Tetrahedron letters》2009,50(44):6057-6059
Novel long-chain dialkyl fluorene-9,9-dicarboxylates were synthesized by treating fluorene with lithium diisopropylamide followed by alkyl chloroformates. The fluorene derivatives were readily electro-oxidized to form electroactive films on the surface of a glassy carbon electrode. From the viewpoint of suitable potential window (from −2.5 to 1.5 V vs Ag/Ag+), cyclic voltammograms of the films indicated the electroactive properties of the fluorene derivatives that make them good candidates for electrochemical capacitor materials. 相似文献
899.
900.
Daisuke Yamaguchi 《International Journal of Approximate Reasoning》2009,51(1):89-98
Pawlak’s attribute dependency degree model is applicable to feature selection in pattern recognition. However, the dependency degrees given by the model are often inadequately computed as a result of the indiscernibility relation. This paper discusses an improvement to Pawlak’s model and presents a new attribute dependency function. The proposed model is based on decision-relative discernibility matrices and measures how many times condition attributes are used to determine the decision value by referring to the matrix. The proposed dependency degree is computed by considering the two cases that two decision values are equal or unequal. A feature of the proposed model is that attribute dependency degrees have significant properties related to those of Armstrong’s axioms. An advantage of the proposed model is that data efficiency is considered in the computation of dependency degrees. It is shown through examples that the proposed model is able to compute dependency degrees more strictly than Pawlak’s model. 相似文献