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81.
Changho Jung Hideyuki Tsuboi Michihisa Koyama Momoji Kubo Ewa Broclawik Akira Miyamoto 《Catalysis Today》2006,111(3-4):322-327
CO adsorption over Pd4 and Pt4 cluster supported by c-ZrO2(1 1 1) and CeO2(1 1 1) catalyst systems was investigated using periodic density functional method in order to clarify the support effect on CO activation. We found that the support increases the CO activation for bridge and three-fold sites but decreases for the atop site. Moreover, it was found that the support changes the site preference for the CO adsorption. Bridge site on both the Pt4/c-ZrO2 and Pt4/CeO2 show larger CO adsorption energies than those on the other sites while the atop site is energetically preferable on isolated Pt4 cluster. c-ZrO2 supported Pd shows the largest CO activation with large charge transfer from the catalyst to the CO molecule. This reveals that ZrO2 supported Pd can be a good catalyst for CO activation because of its higher probability to the three-fold site CO adsorption. We also found that positively charged M4 clusters on the support keep their strong electron-donating properties and have enough charge density to contribute to the activation of an adsorbed CO molecule by a charge transfer. 相似文献
82.
Hiroshi Kajino Hiromi Arai Hisashi Kashima 《Data mining and knowledge discovery》2014,28(5-6):1314-1335
This paper proposes a crowdsourcing quality control method with worker-privacy preservation. Crowdsourcing allows us to outsource tasks to a number of workers. The results of tasks obtained in crowdsourcing are often low-quality due to the difference in the degree of skill. Therefore, we need quality control methods to estimate reliable results from low-quality results. In this paper, we point out privacy problems of workers in crowdsourcing. Personal information of workers can be inferred from the results provided by each worker. To formulate and to address the privacy problems, we define a worker-private quality control problem, a variation of the quality control problem that preserves privacy of workers. We propose a worker-private latent class protocol where a requester can estimate the true results with worker privacy preserved. The key ideas are decentralization of computation and introduction of secure computation. We theoretically guarantee the security of the proposed protocol and experimentally examine the computational efficiency and accuracy. 相似文献
83.
To reveal the effect of the nigrosine dye, that the addition of the dye lowers the crystallization point (Tc) of molten polyamide resins with substantially no shift in the melting point (Tm), thus suppressing the crystallization enhancement of the crystalline nucleation agents, the characteristics of polyamide 66 (PA‐66) containing nigrosine dye EX (N‐EX) were investigated. Differential scanning calorimetry (DSC) analysis showed that the addition of N‐EX reduced the crystallization rate and Tc of molten PA‐66 with substantially no shift in Tm, and the crystallization enthalpy per unit of weight of PA‐66 was substantially constant. Tc of molten PA‐66 was lowered with an increase in the amount of N‐EX and reached its maximum at 13 wt % N‐EX. Dynamic mechanical analysis showed that the glass‐transition temperature and the secondary glass‐transition temperature increased with an increasing amount of the dye. On the other hand, the DSC and X‐ray diffraction results indicated that no dye molecule was present in the crystal structure of PA‐66. This effect of the nigrosine dye on PA‐66 is in contrast to those of crystalline nucleation agents, plasticizers, and antiplasticizers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3270–3274, 2006 相似文献
84.
Zhaoxia Song Hiroyasu Nishiguchi Wei Liu Hiroshi Yamada Akihide Takami Kumiko Kudo Katsutoshi Nagaoka Yusaku Takita 《Catalysis Letters》2006,111(3-4):169-171
Redox properties of CeO2 and Pt-Rh/CeO2 were studied by temporal analysis of products (TAP) method using alternative pulses of CO and O2. A portion of pulsed CO was oxidized to CO2 and a portion of CO was adsorbed on the surface. Pulsing 18O2 onto the catalyst which has surface species derived from CO, evolved CO2 contained no 18O suggesting that the surface species will be carbonate ions. 相似文献
85.
This paper presents a new maritime lifesaving multiple-effect solar still design where several extended wicks feed seawater to their evaporating areas by capillary force, and the resulting water vapor diffuses and condenses on facing wicks with the condensate flowing through the wicks into storage bags. A theoretical analysis showed that a temperature drop through diffusion layers between evaporating and condensing wicks slowly increases in the main evaporating areas and rapidly near salt depositions whereas the evaporation rate decreases slowly in the main area and rapidly near salt depositions. These changes are caused by increases in salt concentrations and resulting boiling point elevation. With steady-state transfer analysis, the proposed still is predicted to produce about 15 kg m −2d−1 fresh water on a sunny day of 22 MJm−2d−1 solar radiation, showing a potential to be a maritime lifesaving desalinator. 相似文献
86.
This paper presents a simplified method for the chemical synthesis of cholest-4-en-3-one, which is a naturally occurring steroid
and a salient intermediate in steroid chemistry. Pyridinium chlorochromate (PCC) in refluxing benzene has been found to be
an effective and convenient reagent for the oxidation and concomitant isomerization of cholest-5-en-3β-ol (cholesterol) to
cholest-4-en-3-one in high yield. Also described are the carbon-13 nuclear magnetic resonance spectral properties of cholest-4-en-3-one
and of the isolated reaction intermediate cholest-5-en-3-one.
Based on a paper presented at the Symposium on Plant and Fungal Sterols: Biosynthesis Metabolism and function held at the
AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献
87.
Tsuyoshi Hagio Kazuo Kobayashi Hisayoshi Yoshida Hiroaki Yasunaga Hiroshi Nishikawa 《Journal of the American Ceramic Society》1989,72(8):1482-1484
Pressureless sintering of hexagonal boron nitride (BN) was performed using a powder activated by mechano-chemical treatments. Physical properties of the sintered BN bodies depend on the type of starting powder and the conditions of the treatments. The BN body, which was obtained at 2000°C using an appropriate activated powder, was 99 wt% pure and was excellent in mechanical and physical properties, in spite of its low density (1.64 g/cm3 ). 相似文献
88.
Keiji Mimura Susumu Yukawa Yoshio Mori Kazuya Okada Masatoshi Mune Osamu Nishikawa Akira Hibino Miyahiko Sonobe Tetuya Goto Hiroshi Nomoto 《Lipids》1991,26(12):1102-1107
We investigated the effect of platelet-activating factor (PAF) and of the PAF specific antagonist CV-6209 on plasma lipid
metabolism, and particularly on post-heparin plasma lipolytic activity in male Wistar rats. Lipoprotein lipase (LPL) activity
was enhanced by intravenous injection of PAF before intravenous injection of heparin when the PAF dose was low (0.2 μg/kg).
PAF activated hepatic triacylglycerol lipase (HTGL) activity dose-dependently. Plasma triacylglycerols (TG) significantly
decreased with the activation of LPL and/or HTGL. Plasma total cholesterol (TC) and phospholipid (PL) levels decreased at
a low dose of PAF (0.2 μg/kg), but increased when higher doses were used. The PAF antagonist CV-6209 partially reversed the
PAF induced effects on HTGL, TC and PL.
Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl
Ether Lipids, Tokyo, Japan, May 1989. 相似文献
89.
Isao Mochida Kenjiro Iwamoto Tsutomu Tahara Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):603-609
Reactivities of several coals of different ranks have been examined in degrading extractions with aromatic solvents under apparently non-hydrogenative reaction conditions. Pyrene and A240 pitch liquefied the fusible coals in high yields and the slightly-fusible coals in moderate yields, indicating the importance of fusibility in such liquefaction processes. A240-LS pitch is a powerful solvent for slightly-fusible coals. Considerable amounts of pyridine- or THF-soluble fractions were produced especially with A240-LS pitch. A240 pitch is a better solvent than pyrene for some slightly-fusible coals. However, the extent of depolymerization of liquefied coal, pyridine- or THF-solubility, was definitely inferior. Yields of such fractions are higher for lower-rank coals. The mechanism of coal liquefaction under apparently non-hydrogenative conditions is discussed with emphasis on the stabilization of thermal fragments derived from the coal. 相似文献
90.
Takaho Kaneda Toshio Katsura Kanji Nakagawa Hiroshi Makino Masao Horio 《应用聚合物科学杂志》1986,32(1):3151-3176
The polyimides based on 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) described in Part I of this series were dissolved in p-chlorophenol and spun into fibers using a coagulating bath of ethanol. The fibers as spun had in general low tenacities and low moduli, but a heat treatment at 300–500°C under tension produced a remarkable increase in strength and modulus, and fibers with a tensile strength of 26 g/den (3.1 GPa) and an initial modulus higher than 1,000 g/den (120 GPa) could be obtained. Thus, the annealed fibers of polyimides are comparable to aramid fibers in mechanical properties. To heating in air and in the saturated steam, the polyimide fibers showed higher resistance than the aramid fibers. The polyimide fibers surpassed the aramid fibers in resistance to acid treatment and ultraviolet (UV) irradiation, but were inferior in resistance to alkali treatment. The annealed fibers of polyimides displayed distinct X-ray diffraction patterns. The chain repeat distance of 20.5 Å determined on the fibers of polyimide prepared from BPDA and o-tolidine, and 20.6 Å determined on the fibers of polyimide derived from BPDA and 3,4′-diaminodiphenyl ether are reasonable when the dimensions of monomeric units and the shapes of the molecular chains are considered. The X-ray reflections of both polyimide fibers were indexed satisfactorily on the basis of postulated unit cells. 相似文献