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101.
Otsubo K Haraguchi T Sakata O Fujiwara A Kitagawa H 《Journal of the American Chemical Society》2012,134(23):9605-9608
Fabrication of a crystalline ordered thin film based on the porous metal-organic frameworks (MOFs) is one of the practical applications of the future functional nanomaterials. Here, we report the creation of a highly oriented three-dimensional (3-D) porous pillared-layer-type MOF thin film on a metal substrate using a step-by-step approach based on liquid-phase epitaxy. Synchrotron X-ray diffraction (XRD) study clearly indicates that the thin film is crystalline and its orientation is highly controlled in both horizontal and vertical directions relative to the substrate. This report provides the first confirmation of details of not only the crystallinity but also the orientation of 3-D MOF thin film using synchrotron XRD. Moreover, we also demonstrate its guest adsorption/desorption behavior by using in situ XRD measurements. The results presented here would promise useful insights for fabrication of MOF-based nanodevices in the future. 相似文献
102.
Kazuki Tajima Yasusei Yamada Shanhu Bao Masahisa Okada Kazuki Yoshimura 《Solid State Ionics》2009,180(6-8):654-658
We investigated the electrochemical property of Ta2O5 thin film for all-solid-state switchable mirror glass. The film was deposited by reactive dc magnetron sputtering in a mixture gas of argon and oxygen. The current density of the film covered WO3/ITO/glass was decreased with decreasing argon/oxygen ratio and working pressure measured by cyclic voltammetry. The film deposited at argon/oxygen ratio of 4.7 and working pressure of 1.0 Pa had better electrochemical property than that of other deposition condition. Its estimated proton conductivity was 2.1 × 10? 9 S/cm by conventional ac impedance method. However, the device using the film showed poor optical switching property. The transmittance change of the device at a wavelength of 670 nm was only 16% by applying voltage. On the other hand, the device using the film deposited at working pressure of 0.7 Pa was able to switch its optical switching property from reflective of 0.1% to transparent states of 44% within 15 s. These results indicate that the suitable deposition condition of the Ta2O5 thin film existed to be used for all-solid-state switchable mirror glass. 相似文献
103.
Haruki Koike Yohei Iguchi Kentaro Sahashi Masahisa Katsuno 《Molecules (Basel, Switzerland)》2021,26(16)
Amyloidosis is a term referring to a group of various protein-misfolding diseases wherein normally soluble proteins form aggregates as insoluble amyloid fibrils. How, or whether, amyloid fibrils contribute to tissue damage in amyloidosis has been the topic of debate. In vitro studies have demonstrated the appearance of small globular oligomeric species during the incubation of amyloid beta peptide (Aβ). Nerve biopsy specimens from patients with systemic amyloidosis have suggested that globular structures similar to Aβ oligomers were generated from amorphous electron-dense materials and later developed into mature amyloid fibrils. Schwann cells adjacent to amyloid fibrils become atrophic and degenerative, suggesting that the direct tissue damage induced by amyloid fibrils plays an important role in systemic amyloidosis. In contrast, there is increasing evidence that oligomers, rather than amyloid fibrils, are responsible for cell death in neurodegenerative diseases, particularly Alzheimer’s disease. Disease-modifying therapies based on the pathophysiology of amyloidosis have now become available. Aducanumab, a human monoclonal antibody against the aggregated form of Aβ, was recently approved for Alzheimer’s disease, and other monoclonal antibodies, including gantenerumab, solanezumab, and lecanemab, could also be up for approval. As many other agents for amyloidosis will be developed in the future, studies to develop sensitive clinical scales for identifying improvement and markers that can act as surrogates for clinical scales should be conducted. 相似文献
104.
We study the semileptonic branching fraction of the B-meson into the higher resonance of the charmed meson D** by using the Bjorken sum rule and the heavy quark effective theory (HQET). This sum rule and the current experiment of the B-meson semileptonic decay into D and D* predict that the branching ratio D**lνl is about 1.7%. This predicted value is larger than the value obtained by various models. 相似文献
105.
A new upwind finite element scheme for the incompressible Navier-Stokes equations at high Reynolds number is presented. The idea of the upwind technique is based on the choice of upwind and downwind points. This scheme can approximate the convection term to third-order accuracy when these points are located at suitable positions. From the practical viewpoint of computation, the algorithm of the pressure Poisson equation procedure is adopted in the framework of the finite element method. Numerical results of flow problems in a cavity and past a circular cylinder show excellent dependence of the solutions on the Reynolds number. The influence of rounding errors causing Karman vortex shedding is also discussed in the latter problem. 相似文献
106.
Masahisa Wada 《Journal of Polymer Science.Polymer Physics》2002,40(11):1095-1102
Measurements of the thermal expansion coefficients (TECs) of cellulose crystals in the lateral direction are reported. Oriented films of highly crystalline cellulose Iβ and IIII were prepared and then investigated with X‐ray diffraction at specific temperatures from room temperature to 250 °C during the heating process. Cellulose Iβ underwent a transition into the high‐temperature phase with the temperature increasing above 220–230 °C; cellulose IIII was transformed into cellulose Iβ when the sample was heated above 200 °C. Therefore, the TECs of Iβ and IIII below 200 °C were measured. For cellulose Iβ, the TEC of the a axis increased linearly from room temperature at αa = 4.3 × 10?5 °C?1 to 200 °C at αa = 17.0 × 10?5 °C?1, but the TEC of the b axis was constant at αb = 0.5 × 10?5 °C?1. Like cellulose Iβ, cellulose IIII also showed an anisotropic thermal expansion in the lateral direction. The TECs of the a and b axes were αa = 7.6 × 10?5 °C?1 and αb = 0.8 × 10?5 °C?1. The anisotropic thermal expansion behaviors in the lateral direction for Iβ and IIII were closely related to the intermolecular hydrogen‐bonding systems. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1095–1102, 2002 相似文献
107.
108.
In an error detection optical system for optical pick-ups using a parallel plane type half mirror, influence on the differential phase detection (DPD) signal by a coma aberration was simulated. The coma aberration deforms the spot profile on the photodetector and influences the DPD signal level characteristics and the offset characteristics with respect to the objective lens shift. In the 4-segment-type DPD, the coma aberration caused by a half mirror 2.75 mm thick hardly affects the DPD signal if the photodetector is not misaligned. On the other hand, the 2-segment-type DPD has a small offset variation with respect to the objective lens shift and a large variation of the DPD signal level against the misalignment of the photodetector in comparison with the 4-segment-type DPD when there is no coma aberration. In the presence of a coma aberration, however, these variations of the 2-segment-type DPD are suppressed by choosing a pair of elements without the coma apex part of the spot. 相似文献
109.
Takayuki Obata Fumio Shishido Masahisa Koga Hiroo Ikehira Fukuko Kimura Katsuya Yoshida 《Magnetic resonance imaging》1996,14(10):1143-1148
The development of phase-contrast magnetic resonance imaging (P-C MRI) provides a noninvasive method for measurement of volumetric blood flow (VFR). We performed P-C MRI to study the effects of physical characteristics on cerebral blood flow. VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI and total cerebral blood flow (tCBF) was calculated by summing up the VFR values in the three vessels. Moreover, we investigated the changes in these blood flows as influenced by age, head size, height, weight, body surface area, and handedness. The blood flows were 142 ± 58 ml/min (mean ± standard deviation) in the basilar artery; and 229 ± 86 ml/min in the left, and 223 ± 58 ml/min in the right internal carotid artery; and tCBF was 617 ± 128 ml/min. Significant increases were observed in head size-related change of VFR in the basilar artery (p = .028) and height-related change of tCBF (p = .045). The other characteristics did not significantly influence any VFR. The results suggest that head size and height may reflect CBF, and that these effects should be considered when changes of CBF are diagnosed. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use. 相似文献
110.
Kanato H Takimiya K Otsubo T Aso Y Nakamura T Araki Y Ito O 《The Journal of organic chemistry》2004,69(21):7183-7189
To promote photoinduced charge separation previously observed for the oligothiophene-fullerene dyads (nT-C60), we have designed an additional attachment with a strongly electron-donating ferrocene at the unsubstituted terminal site of the oligothiophene and synthesized two types of the ferrocene-oligothiophene-fullerene triads, Fc-nT-C60 directly linking the ferrocene to the oligothiophene and Fc-tm-nT-C60 inserting a trimethylene spacer between the ferrocene and the oligothiophene. For the central oligothiophene of the triads, a homologous series of quaterthiophene (4T), octithiophene (8T), and duodecithiophene (12T) are systematically examined. The cyclic voltammograms and electronic absorption spectra of Fc-nT-C60 indicate conjugation between the ferrocene and oligothiophene components. The emission spectra of Fc-nT-C60 measured in toluene demonstrate that the fluorescence of the oligothiophene is markedly quenched, as compared to that observed for the dyads nT-C60. This quenching is explained in terms of the involvement of intramolecular electron transfer in the photophysical decay process. The additionally conjugated ferrocene evidently contributes to the stabilization of charge separation states, thus promoting intramolecular electron transfer. This is corroborated by the observation that the emission spectra of the nonconjugated triads Fc-tm-nT-C60 are essentially similar to the corresponding dyads nT-C60. 相似文献