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931.
Sumida K Brown CM Herm ZR Chavan S Bordiga S Long JR 《Chemical communications (Cambridge, England)》2011,47(4):1157-1159
The hydrogen storage properties of Mg(2)(dobdc) (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate), a metal-organic framework possessing hexagonal one-dimensional channels decorated with unsaturated Mg(2+) coordination sites, have been examined through low- and high-pressure adsorption experiments, infrared spectroscopy, and neutron scattering studies. 相似文献
932.
The previously unknown polycyclic heterocyclic ring systems, namely, [1]benzothieno[2,3-c]naphtho[1,2-h]-quinoline and [1]benzothieno[2,3-c]naphtho[1,2-h][1,2,4]triazolo[4,3-a]quinoline were synthesized via photocyclization of 3-chloro-N-(1′-phenanthryl)benzo[b]thiophene-2-carboxamide. 相似文献
933.
Norihiro Moriyama Hiroki Nagasawa Masakoto Kanezashi Kenji Ito Toshinori Tsuru 《Journal of Sol-Gel Science and Technology》2018,86(1):63-72
Based on their high performance in gas and liquid-phase separations, 1,2-bis(triethoxysilyl)ethane (BTESE)-derived organosilica membranes have attracted much attention. To improve performance, we focused on the acid molar ratio (AR) in sol preparation and its effect on the pore formation mechanism during sol-gel processing. BTESE-derived sols with AR?=?10?4–100 were prepared, and the effect of the AR on the gel structure was evaluated in detail via FT-IR, nuclear magnetic resonance (NMR), N2 adsorption, and positron annihilation lifetime (PAL) measurements. The chemical structure of the gels was confirmed by FT-IR and NMR and showed that sols with the largest number of silanol groups (AR?=?10?2) experienced a significant increase in condensation during the firing process. The porous structures of fired gels characterized by N2 adsorption and PAL measurement showed that the AR?=?10?2 fired gel consisted of a larger number of small pores that had formed during the firing process. Single-gas permeation experiments showed high H2 permeance (5–9?×?10?7?mol/(m2?Pa?s)) and H2/CF4 selectivity (700–20,000). The gas permselectivity (He/H2, H2/N2, and H2/CF4) was highest for the intermediate AR (=10?2), which corresponded to the greatest amount of silanol groups in unfired gels and confirmed that small pores had formed from the condensation of silanol groups during firing. 相似文献
934.
The dynamic behaviors and optical properties of a ZnO plasma plume produced by pulsed laser ablation using a Nd:YAG laser
(wavelength: 532 nm, pulse width: 3 ns) were studied by fast photography using a commercial gated charge coupled device (CCD)
camera linked with a delay circuit and by optical emission spectroscopy at various ambient oxygen pressures. Fast photography
was conducted with a resolving power of 0.25 μs and the expansion behaviors of the laser ablation plume were observed. Plasma
plume expansion velocity decreased with oxygen partial pressure. The flow of the plasma plume in the early stage of expansion
of up to 3 ms agreed well with the drag model. 相似文献
935.
Remarkable Charge Separation and Photocatalytic Efficiency Enhancement through Interconnection of TiO2 Nanoparticles by Hydrothermal Treatment 下载免费PDF全文
Prof. Yusuke Ide Nozomu Inami Hideya Hattori Kanji Saito Dr. Minoru Sohmiya Prof. Nao Tsunoji Prof. Kenji Komaguchi Prof. Tsuneji Sano Prof. Yoshio Bando Prof. Dmitri Golberg Prof. Yoshiyuki Sugahara 《Angewandte Chemie (International ed. in English)》2016,55(11):3600-3605
Although tremendous effort has been directed to synthesizing advanced TiO2, it remains difficult to obtain TiO2 exhibiting a photocatalytic efficiency higher than that of P25, a benchmark photocatalyst. P25 is composed of anatase, rutile, and amorphous TiO2 particles, and photoexcited electron transfer and subsequent charge separation at the anatase–rutile particle interfaces explain its high photocatalytic efficiency. Herein, we report on a facile and rational hydrothermal treatment of P25 to selectively convert the amorphous component into crystalline TiO2, which is deposited between the original anatase and rutile particles to increase the particle interfaces and thus enhance charge separation. This process produces a new TiO2 exhibiting a considerably enhanced photocatalytic efficiency. This method of synthesizing this TiO2, inspired by a recently burgeoning zeolite design, promises to make TiO2 applications more feasible and effective. 相似文献
936.
We report first-principle electronic-structure calculations using the local density approximation in the density functional theory for Si(1 0 0) and Al(1 0 0) surfaces. We find a novel class of surface electron states that are distributed not near atomic arrays but float around with the maximum amplitudes being substantially separated from matters. We also find that the origin of the unusual character is quantum spill of electron density from matters and exchange-correlation effects among electrons. 相似文献
937.
Masahiro Yoshida Kenji Ishii Ignace Jarrige Tetsu Watanuki Kazutaka Kudo Yoji Koike Ken'ichi Kumagai Nozomu Hiraoka Hirofumi Ishii Ku‐Ding Tsuei Jun'ichiro Mizuki 《Journal of synchrotron radiation》2014,21(1):131-135
A single‐crystal momentum‐resolved resonant inelastic X‐ray scattering (RIXS) experiment under high pressure using an originally designed diamond anvil cell (DAC) is reported. The diamond‐in/diamond‐out geometry was adopted with both the incident and scattered beams passing through a 1 mm‐thick diamond. This enabled us to cover wide momentum space keeping the scattering angle condition near 90°. Elastic and inelastic scattering from the diamond was drastically reduced using a pinhole placed after the DAC. Measurement of the momentum‐resolved RIXS spectra of Sr2.5Ca11.5Cu24O41 at the Cu K‐edge was thus successful. Though the inelastic intensity becomes weaker by two orders than the ambient pressure, RIXS spectra both at the center and the edge of the Brillouin zone were obtained at 3 GPa and low‐energy electronic excitations of the cuprate were found to change with pressure. 相似文献
938.
Takahiro Murata Masanori Torisaka Hiromichi Takebe Kenji Morinaga 《Journal of Non》1997,220(2-3):139-146
Absorption spectra of Cr ions in multi-component oxide glasses melted in Ar were measured. The integrated extinction coefficient is used as a parameter to analyze the redox reaction of Cr3+ and Cr6+ in glass samples. The relative content of Cr6+ increased and that of Cr3+ decreased with increasing basicity in silicate and borate glasses; this result is consistent with previous studies. On the contrary, only Cr3+ exist in phosphate glasses. Cr4+ ions were found only in aluminate, gallate and alumino-silicate glasses with modifier contents ≥ 60 mol%. The relationship between point defects and Cr4+ formation is examined on the basis of electron spin resonance measurements. We concluded that the superoxide ion radical (O2−) and the peroxy bonding (-O-O-) oxidize Cr3+ to Cr4+ in aluminate, gallate, and alumino-silicate glasses. 相似文献
939.
Kenji Monde Tohru TaniguchiNobuaki Miura Shin-Ichiro Nishimura Nobuyuki HaradaRina K Dukor Laurence A Nafie 《Tetrahedron letters》2003,44(32):6017-6020
Cruciferous phytoalexin related metabolites, (−)-dioxibrassinin (1) and (−)-3-cyanomethyl-3-hydroxyoxindole (2) were prepared from isatin as racemates and were resolved by chiral HPLC. Their absolute configurations were determined by the new chiroptical technique, vibrational circular dichroism (VCD), as well as by the conventional electronic circular dichroism (ECD). It is concluded that the absolute configurations of the naturally occurring (−)-1 and (−)-2 are both S. 相似文献
940.
Kenji Takada Minoru Ueda Kohji Minami Masayuki Nishikawa Hideaki Fujita Shohzou Minamide 《Optical Review》2008,15(2):130-132
We present a novel approach to the miniaturization of an imaging system with high resolution and high optical magnification
for camera phones. An optical zoom system with a mechanical shutter has been designed and developed, the mechanical shutter
being necessary to assure high image quality. The shutter is integrated with the zooming lens group, which allows the zoom
lens unit to be downsized. Performance of the zoom lens unit accommodates an image sensor of over five-mega-pixels and fulfills
all the requirements of a camera phone. 相似文献