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721.
We study four-dimensional non-Abelian gauge theories with classical moduli. Introducing a chemical potential for a flavor charge causes moduli to become unstable and start condensing. We show that the moduli condensation in the presence of a chemical potential generates non-Abelian field strength condensates. These condensates are homogeneous but non-isotropic. The end point of the condensation process is a stable homogeneous, but non-isotropic, vacuum in which both gauge and flavor symmetries and the rotational invariance are spontaneously broken. Possible applications of this phenomenon for the gauge theory/string theory correspondence and in cosmology are briefly discussed. 相似文献
722.
Okoshi K Sano N Okumura T Tagaya A Magoshi J Koike Y Fujiki M Watanabe J 《Journal of colloid and interface science》2003,263(2):473-477
A novel coloration phenomenon in a colloidal dispersion with an amphiphilic polymer was found. The dispersion consists of tetrahydrofuran (THF), an aqueous solution of sodium thiosulfate (Na(2)S(2)O(3).5H(2)O), and hydroxypropylcellulose (HPC). The dispersion was emulsified by HPC as an amphiphilic polymer, so that the aqueous phase was confined in droplets in the THF matrix. It typically appeared bluish violet at room temperature and turned into blue with increasing temperature. In this system, the refractive indices of the inside and outside of the droplet coincided at a certain wavelength at which the light passes through without scattering, which is called the Christiansen effect. The color observed was successfully simulated by Mie's scattering theory in combination with the Christiansen effect. 相似文献
723.
Hiroki Arai Prof. Hisahiro Sasabe Hisaki Tsuneyama Kengo Kumada Prof. Junji Kido 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):10869-10874
Recently, researchers have focused on thermally activated delayed fluorescence (TADF) for efficient future lighting and displays. Among TADF emitters, a combination of triazine and acridine is a promising candidate for realizing high-efficiency organic light-emitting devices (OLEDs). However, simultaneous development of perfect horizontal orientation (Θ=100 %) and an external quantum efficiency (EQE) of over 40 % is still challenging. Here, to obtain insights for further improvements of a triazine/acridine combination, various asymmetric spirobiacridine (SBA)-based TADF emitters with a unity photoluminescence quantum yield and high Θ ratio of over 80 % were developed. Furthermore, the substitution effects of the triazine acceptor unit on the photophysical properties were studied, including molecular orientations and OLED performance. The corresponding OLED exhibited sky-blue emission with a high EQE of over 30 %. 相似文献
724.
Characteristics of Diffraction Gratings Fabricated by the Two-Beam Interference Method Using Photosensitive Hybrid Gel Films 总被引:1,自引:0,他引:1
Tohge Noboru Ueno Ryuichi Chiba Fumio Kintaka Kenji Nishii Junji 《Journal of Sol-Gel Science and Technology》2000,19(1-3):119-123
Diffraction gratings of arbitrary periods have been fabricated by the two-beam interference method using photosensitive ZrO2 gel films and characterized. The ZrO2 gel films were formed on Si or silica glass substrates from sols that were derived from Zr-butoxide modified chemically with benzoylacetone. The gel films were irradiated with two interference beams from a He-Cd laser (325 nm) and then leached in ethyl alcohol. The above process gave uniform surface-relief gratings of periods ranging from 1.0 to 0.5 m, depending on the incidence angle of the interference beams. The diffraction efficiency, measured in the Littrow configuration using a He-Ne laser (633 nm), showed polarization dependence for the grating of 0.5 m period but not for the gratings of 1.0 m period. The maximum diffraction efficiency was 18% for the grating of 1.0 m period and 28% for that of 0.5 m period in the reflection mode. The present study has proved that the photosensitive gel films are versatile in fabrication of optical devices. 相似文献
725.
Shikinaka K Aizawa K Murakami Y Osada Y Tokita M Watanabe J Shigehara K 《Journal of colloid and interface science》2012,369(1):470-476
Inorganic/organic hybrids were obtained by the sol-gel type organic modification reaction of Laponite sidewalls with poly(ethylene glycol) (PEG) bearing alkoxysiloxy terminal functionality. By casting an aqueous dispersion of the hybrid, the flexible and transparent hybrid films were obtained. Regardless of the inorganic/organic component ratio, the hybrid film had the ordered structure of Laponite in-plane flat arrays. The mechanical strength of hybrid films was drastically improved by the presence of cross-linking among alkoxysilyl functionalities of PEG terminals and the absence of PEG crystallines. Hybrid films, especially those that consisted of PEG with short chain, showed good mechanical properties that originate from quasi-homogeneous dispersion of components due to anchoring of PEG terminal to Laponite sidewall and interaction of PEG to Laponite surface. 相似文献
726.
JY Hu YJ Pu G Nakata S Kawata H Sasabe J Kido 《Chemical communications (Cambridge, England)》2012,48(67):8434-8436
A pyrene-containing single-molecule excimer-emitting compound, 1,8-bis(pyren-2-yl)naphthalene (BPyN), was synthesized. With BPyN as a host emitter, C545T-based green OLEDs were fabricated, exhibiting high efficiencies of 22 lm W(-1), 22 cd A(-1) and 6.2% external quantum efficiency (EQE) at 100 cd m(-2), and 19 lm W(-1), 22 cd A(-1) and 6.2% EQE at 1000 cd m(-2). 相似文献
727.
Junji Iwahara Jonathan M. Wojciak Robert T. Clubb 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2001,153(2):262-266
We present a new NMR experiment for estimating the type and degree of sugar-puckering in high-molecular-weight unlabeled DNA molecules. The experiment consists of a NOESY sequence preceded by a constant-time scalar coupling period. Two subexperiments are compared, each differing in the amount of time the (3)J(H3'H2') and (3)J(H3'H2") couplings are active on the H3' magnetization. The resultant data are easy to analyze, since a comparison of the signal intensities of any resolved NOE cross peak originating from H3' atoms of the duplex can be used to estimate the sum of the (3)J(H3'H2') and (3)J(H3'H2") couplings and thus the puckering type of the deoxyribose ring. Isotope filters to eliminate signals of the (13)C-labeled component in the F1-dimension are implemented, facilitating analyses of high-molecular-weight protein-DNA complexes containing (13)C-labeled protein and unlabeled DNA. The utility of the experiment is demonstrated on the 26-kDa Dead Ringer protein-DNA complex and reveals that the DNA uniformly adopts the S-type configuration when bound to protein. 相似文献
728.
Junji Furukawa Hirotoshi Amano Ryuichi Hirai 《Journal of polymer science. Part A, Polymer chemistry》1972,10(3):681-688
Alternating copolymerizations of butadiene with propylene and other olefins were investigated by using VO(acac)2–Et3Al–Et2AlCl system as catalyst. Butadiene–propylene copolymer with high degree of alternation was prepared with a monomer feed ratio (propylene/butadiene) of 4. Alternating copolymers of butadiene and other terminal olefins such as butene-1, pentene-1, dodecene-1, and octadiene-1,7 were also obtained. However, the butadiene–butene-2 copolymerization did not yield an alternating copolymer but a trans-1,4-polybutadiene. 相似文献
729.
Yamada I Yamashita N Tani K Einishi T Saito M Fukumi K Nishii J 《Optics letters》2011,36(19):3882-3884
A mid-IR wire-grid polarizer with a 500 nm pitch was fabricated on a low toxic chalcogenide glass (Sb-Ge-Sn-S system) by the thermal imprinting of periodic grating followed by the thermal evaporation of Al metal. After imprinting, deposition of Al on the grating at an oblique angle produced a wire-grid polarizer. The fabricated polarizer showed polarization with TM transmittance greater than 60% at 5-9 μm wavelengths and an extinction ratio greater than 20 dB at 3.5-11 μm wavelengths. This polarizer with a high extinction ratio can be fabricated more simply and less expensively than conventional IR polarizers. 相似文献
730.
Tatsuo Matsushima Anton Kokalj Hideo Orita Toshitaka Kubo Masataka Sakurai Takahiro Kondo Junji Nakamura 《Surface science》2012,606(13-14):1029-1036
A sharp change in the N2 emission channel from N2O(a) → N2(g) + O(a) to N(a) + N(a) → N2(g) has been found at around 500 K in a steady-state NO + D2 reaction over stepped Pd(211) = [(S)3(111) × (100)] by means of angle-resolved desorption. The desorbing N2 is highly collimated at around 30° off normal toward the step-down direction below about 500 K due to the intermediate N2O decomposition, whereas, above 500 K, the near normally directed desorption due to the recombination of N(a) is relatively enhanced. The N2O decomposition channel is promoted when the reaction is carried out with hydrogen (deuterium) and the channel change is accelerated by quick changes of the amounts of surface hydrogen and oxygen (or NO(a)) into the opposite directions, and enhanced nitrogen removal as ammonia on the resultant hydrogen-rich surface. In the steady-state NO + CO reaction, the N2 emission channel gradually changes above 500 K toward recombination. A model for the off-normal N2 emission is briefly described. 相似文献