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1.
Synthesis of Highly Active Sub‐Nanometer Pt@Rh Core–Shell Nanocatalyst via a Photochemical Route: Porous Titania Nanoplates as a Superior Photoactive Support
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2.
Etching characteristics of high-k dielectric materials (HfO2) and metal electrode materials (Pt, TaN) have been studied in high-density chlorine-containing plasmas at pressures around 10 mTorr. The etching of HfO2 was performed in BCl3 without rf biasing, giving an etch rate of about 5 nm/min with a high selectivity of >10 over Si and SiO2. The etching of Pt and TaN was performed in Ar/O2 with high rf biasing and in Ar/Cl2 with low rf biasing, respectively, giving a Pt etch rate of about several tens nm/min and a TaN etch rate of about 200 nm/min with a high selectivity of >8 over HfO2 and SiO2. The etched profiles were outwardly tapered for Pt, owing to the redeposition of etch or sputter products on feature sidewalls, while the TaN profiles were almost anisotropic, probably owing to the ion-enhanced etching that occurred. 相似文献
3.
This study clarifies the absorption behavior of micro-droplets of water on treated paper to support the design of functional
microstructures, such as electronics and micro-fluid channels, on paper. The period of time between when a micro-droplet of
water ejected from an ink-jet head lands on the paper’s surface and its complete disappearance by absorption was defined as
the micro-sizing degree (MSD), and an MSD measurement method was established. The MSD was evaluated using microscopic high-speed
video images of the side view recorded every millisecond. Several grades of commercially available ink-jet paper media and
laboratory sheets having different levels of water repellency prepared from a pulp and a sizing agent were examined. The MSD
of commercial ink-jet papers, which are known to absorb water very quickly, was 3–6 ms. Weakly sized laboratory sheets exhibited
a lower MSD of 2–3 ms. The absorption behavior was analyzed in terms of the capillary pressure with and without the Laplace
pressure; the theoretical and experimental results agreed moderately well. The results indicated that the Laplace pressure
cannot be neglected in the analysis. The MSD of a wet surface where a preceding micro-droplet had already landed was higher
than that on a dry or partially wet surface, presumably because water remains inside pores for an unexpectedly long time. 相似文献
4.
We describe a 6 year old girl with chorea following cardiac surgery, the first such report in Japan. The radical operation for total anomalous pulmonary venous return was carried out at the age of 11 months under hypothermia. Seven days after the operation, a sudden onset of irritability, dysphagia, chorea, generalized, hypotonia, and complete external ophthalmoplegia were seen. These symptoms diminished gradually, but chorea remained. We speculated that the cause of chorea arose from the cardiac surgery under hypothermia. It is necessary to consider 'cardiac surgery' as one of the triggers of certain movement disorders including chorea. We tried treatment with haloperidol, pimozide, and several other drugs; only pimozide was effective in decreasing chorea without any side-effects. 相似文献
5.
Diffusion of vanadium,chromium, and manganese in copper 总被引:2,自引:0,他引:2
Kazutomo Hoshino Yoshiaki Iijima Ken-Ichi Hirano 《Metallurgical and Materials Transactions A》1977,8(3):469-472
The diffusion coefficients of vanadium, chromium and manaanese in copper have been determined by the residual activity method
with radioactive tracers V48, Cr51 and Mn54 in the temperature ranges between 955 and 1342 K, between 999 and 1338 K and between 971 and 1253 K, respectively. The temperature
dependence of the diffusion coefficients is expressed by the following Arrhenius equations along with the probable errors:D
V/Cu = (2.48
-0.44
+0.53
) x 10−4 exp [-(215 ± 2) kJ mol−1/RT] m2 per s,D
Cr/Cu = (0.337
-0.090
+0.124
) x 10−4 exp [-(195 ± 3) kJ mol−1/RT] m2 per s,D
Mn/Cu = (1.02
-0.18
+0.22
) x 10−4 exp [-(200 ± 2) kJ mol−1/RT] m2 per s.
Anomalous penetration profiles for the diffusion of Cr51 and Mn54 in the present results suggest that experimental results onD
Cr/Cu andD
Mn/Cu in the past have been influenced by oxidation and evaporation of the chemically active radiotracers during annealing for
diffusion.
formerly Graduate Student, Tohoku University 相似文献
6.
Kazutomo Hoshino Yoshiaki IIjima Ken-Ichi Hirano 《Metallurgical and Materials Transactions A》1982,13(7):1135-1139
Interdiffusion coefficients in copper-rich copper-zinc solid solutions containing up to 8 at. pct of Zn at 1168 K have been
determined by Matano's analysis using semi-infinite diffusion couples consisting of pure copper and Cu-Zn alloys with Kirkendall
markers. From the marker shift and Darken's relation, intrinsic diffusion coefficients, DZn and DCu, in the alloys containing 3.2 and 4.7 at. pct of Zn have been determined. Further, using thin plate couples, DZn and DCu in Cu alloys containing 0.9, 2.3, 3.5, and 4.6 at. pct of Zn at 1168 K have been determined by Heumann's method. The ratio
of the intrinsic diffusion coefficients, DZn/DCu, has been found to be about two for all the compositions examined. Using the values of the intrinsic diffusion coefficient
of copper at infinite dilution of zinc obtained by extrapolating the concentration dependence of DCu, and the self- and impurity diffusion coefficients in pure copper, the vacancy flow factor has been estimated to be - 0.22-0.15
+0.06 at 1168 K. By combining this value of the vacancy flow factor with the solute enhancement factor of solvent diffusion determined
by Peterson and Rothman, the correlation factor for impurity diffusion of Zn in Cu at 1168 K has been evaluated to be 0.5,
which is in good agreement with the value of 0.47 determined by Peterson and Rothman based on the isotope effect measurement.
KAZUTOMO HOSHINO, formerly Graduate Student, Tohoku University is now with Materials Science Division, Argonne National Laboratory,
Argonne, IL 60439. YOSHIAKI IIJIMA, Instructor, and KENICHI HIRANO, Professor, are both with the Department of Materials Science,
Faculty of Engineering, Tohoku University, Sendai 980, Japan. 相似文献
7.
Ondrej L. Krivanek Niklas Dellby Matthew F. Murfitt Matthew F. Chisholm Timothy J. Pennycook Kazutomo Suenaga Valeria Nicolosi 《Ultramicroscopy》2010
Aberration correction of the scanning transmission electron microscope (STEM) has made it possible to reach probe sizes close to 1 Å at 60 keV, an operating energy that avoids direct knock-on damage in materials consisting of light atoms such as B, C, N and O. Although greatly reduced, some radiation damage is still present at this energy, and this limits the maximum usable electron dose. Elemental analysis by electron energy loss spectroscopy (EELS) is then usefully supplemented by annular dark field (ADF) imaging, for which the signal is larger. Because of its strong Z dependence, ADF allows the chemical identification of individual atoms, both heavy and light, and it can also record the atomic motion of individual heavy atoms in considerable detail. We illustrate these points by ADF images and EELS of nanotubes containing nanopods filled with single atoms of Er, and by ADF images of graphene with impurity atoms. 相似文献
8.
Chemical Growth of 1T‐TaS2 Monolayer and Thin Films: Robust Charge Density Wave Transitions and High Bolometric Responsivity
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Xinsheng Wang Haining Liu Juanxia Wu Junhao Lin Wen He Hui Wang Xinghua Shi Kazutomo Suenaga Liming Xie 《Advanced materials (Deerfield Beach, Fla.)》2018,30(38)
Ultrathin two‐dimensional (2D) charge density wave (CDW) materials, with sharp resistance change at the phase‐transition temperature, yet with ultrathin thickness, hold great potential for electrical device applications. However, chemical synthesis of high‐quality samples and observation of the CDW states down to the monolayer limit is still of great challenge. Chemical vapor deposition of 1T‐TaS2 sheets on hexagonal boron nitride (h‐BN) with robust CDW states even down to the monolayer extreme is reported here. Further, based on the near commensurate CDW to incommensurate CDW phase transition with a high temperature coefficient of resistance (TCR), highly responsive room‐temperature bolometers are fabricated by suspending the as‐grown 1T‐TaS2 sheets. 相似文献
9.
Metal-atom migration outside from a defective fullerene cage of a metallofullerene Gd@C(82) (Ca@C(82)), where the Gd(3+) (Ca(2+)) ion is incorporated inside the C(2)(v)()-C(82) cage, is discussed in detail at the B3LYP DFT level of theory. The metal-atom migrations are initiated by the formation of vacancy-type defects involving two coordinatively unsaturated C atoms. This step, which is assumed to proceed due to energy-particle irradiation, leads to the formation of antibonding orbitals between the two C atoms. Since the antibonding orbitals can interact with vacant d-orbitals of the Gd(3)(+)() ion in an in-phase fashion, the attractive interactions allow the Gd ion to insert into the two C atoms in the defect. As a result, the metal ion passes through the defect under energy-particle irradiation. In contrast, the Ca(2+) ion with the vacant s-orbitals does not have such orbital interactions, and thus, a C-C bond is reformed between the two C atoms, which prohibits the Ca ion from penetrating the defected C(82) cage. DFT calculations nicely demonstrate that the orbital interactions control metal-atom migration around the defect site using their orbital symmetries, and therefore, the vacancy-type defect acts as a "gate" that permits a specific atom to go out from a defected fullerene cage. 相似文献
10.
Two different growth modes of carbon nanotubes (CNTs) are identified in ethylene chemical vapour deposition (CVD) using SiO2 as support. With a series of electron microscopy observations, we have found that small-diameter nanotubes favor a root-growth mechanism on nanoporous SiO2 support, while nanotubes with larger diameters prefer a tip-growth. The dependence of growth mode on tube diameter is explained in terms of the porosity of the support and the size distribution of the catalyst. Our results provide clues to control growth of CNTs and obtain well-organized nanotube structures. 相似文献