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排序方式: 共有287条查询结果,搜索用时 15 毫秒
81.
Won E Ko BR Adachi I Aihara H Arinstein K Asner DM Aushev T Bakich AM Barberio E Bay A Bhardwaj V Bhuyan B Bischofberger M Bondar A Bozek A Bračko M Brodzicka J Browder TE Chang P Chen A Chen P Cheon BG Chilikin K Cho IS Cho K Choi SK Choi Y Dalseno J Danilov M Doležal Z Drásal Z Drutskoy A Eidelman S Fast JE Gaur V Gabyshev N Garmash A Goh YM Golob B Haba J Hara T Hayasaka K Hayashii H Horii Y Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Inami K Ishikawa A Itoh R Iwabuchi M Iwasaki Y Iwashita T 《Physical review letters》2011,107(22):221801
We report the first observation of the doubly Cabibbo-suppressed decays D(+)→K(+)η((')) using a 791 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The ratio of the branching fractions of doubly Cabibbo-suppressed relative to singly Cabibbo-suppressed D(+)→π(+)η((')) decays are B(D(+)→K(+)η)/B(D(+)→π(+)η)=(3.06±0.43±0.14)% and B(D(+)→K(+)η')/B(D(+)→π(+)η')=(3.77±0.39±0.10)%. From these, we find that the relative final-state phase difference between the tree and annihilation amplitudes in D(+) decays, δ(TA), is (72±9)° or (288±9)°. We also report the most precise measurements of CP asymmetries to date: A(CP)(D(+)→π(+)η)=(+1.74±1.13±0.19)% and A(CP)(D(+)→π(+)η')=(-0.12±1.12±0.17)%. 相似文献
82.
Yue Wang Koki Ogasahara Daisuke Tomihama Radomir Mysliborski Masatoshi Ishida Yongseok Hong Yusuke Notsuka Yoshihisa Yamaoka Tomotaka Murayama Atsuya Muranaka Masanobu Uchiyama Shigeki Mori Yuhsuke Yasutake Susumu Fukatsu Dongho Kim Hiroyuki Furuta 《Angewandte Chemie (International ed. in English)》2020,59(37):16161-16166
The synthesis of organometallic complexes of modified 26π‐conjugated hexaphyrins with absorption and emission capabilities in the third near‐infrared region (NIR‐III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis‐PdII and bis‐PtII complexes of hexaphyrin via N‐confusion modification led to substantial metal dπ–pπ interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO–LUMO energy gap. A remarkable long‐wavelength shift of the lowest S0→S1 absorption beyond 1700 nm was achieved with the bis‐PtII complex, t ‐Pt2‐3 . The emergence of photoacoustic (PA) signals maximized at 1700 nm makes t ‐Pt2‐3 potentially useful as a NIR‐III PA contrast agent. The rigid bis‐PdII complexes, t ‐Pd2‐3 and c ‐Pd2‐3 , are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR‐III‐emissive and photoacoustic‐response capabilities. 相似文献
83.
Asako Hirai Fumitaka Horii Ryozo Kitamaru 《Journal of Polymer Science.Polymer Physics》1980,18(8):1801-1809
Differences in fiber structure between cotton and cuprammonium rayon are studied by a refined broad-line proton NMR analysis of samples swollen with deuterated dimethyl sulfoxide, which has no effect on the spectra but enhances differences in molecular mobility between crystalline and noncrystalline regions. The spectra obtained are decomposed into four components: broad, medium, narrow, and extremely narrow. These components are identified as contributions, respectively, from crystalline and rigid noncrystalline (frozen glassy) material, a noncrystalline glassy component exhibiting local segmental motion, a noncrystalline rubbery component exhibiting liquidlike molecular motion, and protons included in DMSO-d6 as an impurity. The mass fraction of the narrow component in cotton was about 0.01, whereas it was as high as 0.18 in cuprammonium rayon. It is concluded that even in the swollen state, native cellulose is devoid of a liquidlike mobile component, but regenerated cellulose contains a considerable amount of a noncrystalline component involving liquidlike segmental motion of molecules. 相似文献
84.
85.
Kanehira K Banzai T Ogino C Shimizu N Kubota Y Sonezaki S 《Colloids and surfaces. B, Biointerfaces》2008,64(1):10-15
Titanium dioxide (TiO2)/polyacrylic acid (PAA) (TiO2/PAA) particles were formed by mixing PAA and an acidic solution of TiO2 nanoparticles in dimethylformamide (DMF) followed by heat treatment. TEM and particle analysis showed that the resulting particles had a narrow size distribution. The colloid was very stable and aggregation was not observed over a wide pH range (3–9) or at high salt concentration. The residual carboxylic acid of PAA could be modified via EDC/NHS activation to form an amide bond with a protein. An antibody was attached to the hybrid nanoparticle and specific binding to antigen was monitored by surface plasmon resonance. The results suggest that TiO2/PAA nanoparticles are candidates as the base component of a photocatalytic system with potential for substrate selectivity. 相似文献
86.
87.
Dr. Yi-Yang Zhan Daisuke Ogawa Dr. Koki Sano Dr. Xiang Wang Dr. Fumito Araoka Dr. Nobuyuki Sakai Prof. Takayoshi Sasaki Dr. Yasuhiro Ishida 《Angewandte Chemie (International ed. in English)》2023,62(52):e202311451
Unlike absorption-based colors of dyes and pigments, reflection-based colors of photonic crystals, so called “structural colors”, are responsive to external stimuli, but can remain unfaded for over ten million years, and therefore regarded as a next-generation coloring mechanism. However, it is a challenge to rationally design the spectra of structural colors, where one structure gives only one reflection peak defined by Bragg's law, unlike those of absorption-based colors. Here, we report a reconfigurable photonic crystal that exhibits single-peak and double-peak structural colors. This photonic crystal is composed of a colloidal nanosheet in water, which spontaneously adopts a layered structure with single periodicity (407 nm). After a temperature-gradient treatment, the photonic crystal segregates into two regions with shrunken (385 nm) and expanded (448 nm) periodicities, and thus exhibits double reflection peaks that are blue- and red-shifted from the original one, respectively. Notably, the transition between the single-peak and double-peak states is reversible. 相似文献
88.
Takaaki Tanaka Yuna Tomita Koki Honda Marino Fujisawa Akihito Ochiai 《Journal of separation science》2023,46(2):2200638
In this study, composite monoliths with porous structures were prepared using quaternized chitosan and diatom earth for protein separation. Quaternized chitosan (N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride) dissolved in water was mixed with diatom earth and crosslinked with glutaraldehyde under low-temperature conditions to form a cryogel. Interconnected porous monoliths were obtained after removing ice crystals from the cryogel. The monoliths adsorbed bovine serum albumin selectively from the solution mixture of bovine serum albumin and bovine ɤ-globulin, and bovine ɤ-globulin was recovered in the flow-through fraction. The adsorption selectivity was enhanced by changing the solution pH from 6.8 to 5.5. The adsorption of bovine serum albumin by the monolith was replicated at least five times following its washing with a buffer containing 400 mM NaCl and subsequent regeneration with a 10 mM acetate buffer. The composited monolith is a promising adsorbent for the removal of acidic proteins, such as serum albumin contamination in neutral proteins, for example, ɤ-globulins, in bioproduction processes. 相似文献
89.
In the chain compound PrBa2Cu4O8 localization appears simultaneously with a dimensional crossover in the electronic ground state when the scattering rate in the chains exceeds the hopping rate between the chains. Here we report the discovery of a large, transverse magnetoresistance in PrBa2Cu4O8 in the localized regime. This result suggests a novel form of localization whereby electrons retain their metallic (quasi-one-dimensional) character over a microscopic length scale despite the fact that, macroscopically, they exhibit localized (one-dimensional) behavior. 相似文献
90.
Yue Wang Koki Ogasahara Daisuke Tomihama Dr. Radomir Mysliborski Dr. Masatoshi Ishida Yongseok Hong Yusuke Notsuka Prof. Dr. Yoshihisa Yamaoka Tomotaka Murayama Dr. Atsuya Muranaka Prof. Dr. Masanobu Uchiyama Dr. Shigeki Mori Dr. Yuhsuke Yasutake Prof. Dr. Susumu Fukatsu Prof. Dr. Dongho Kim Prof. Dr. Hiroyuki Furuta 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16295-16300
The synthesis of organometallic complexes of modified 26π-conjugated hexaphyrins with absorption and emission capabilities in the third near-infrared region (NIR-III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis-PdII and bis-PtII complexes of hexaphyrin via N-confusion modification led to substantial metal dπ–pπ interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO–LUMO energy gap. A remarkable long-wavelength shift of the lowest S0→S1 absorption beyond 1700 nm was achieved with the bis-PtII complex, t -Pt2-3 . The emergence of photoacoustic (PA) signals maximized at 1700 nm makes t -Pt2-3 potentially useful as a NIR-III PA contrast agent. The rigid bis-PdII complexes, t -Pd2-3 and c -Pd2-3 , are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR-III-emissive and photoacoustic-response capabilities. 相似文献