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51.
Nanoporous structure of the cell walls of polycarbonate foams 总被引:1,自引:0,他引:1
Using CO2 to prepare microcellular polycarbonate foams resulted in a pore diameter of 45 nm and a pore density of 108 cm?2 on the walls of microscale cells, which created nano/micro foams with an open cell structure. In this study, the craze nucleation theory and the bubble nucleation theory of foaming were combined to explain the mechanism of the foaming-induced nanopores (microvoids) on the cell walls. In the foaming process, the strain energy was developed in the cell walls by bubble nucleation and growth. With large strain energy, a nanoporous structure of the cell walls was formed by initiation of crazing. Because the foaming temperature affected the strain energy in the cell wall, the temperature became a key factor of forming microcellular structure as well as the nanopores on the cell walls. Our experimental results showed that the diameter and density of the nanopores were determined by the competitive movements between chain stretching and relaxation. Furthermore, certain solvents, such as acetone, were found to increase the nanopore density of the walls by exploiting the plasticization effect of the solvent on the reduction of surface tension and viscosity. 相似文献
52.
53.
Yoshihiro Sagisaka Itaru Ishibashi Tamotsu Nakamura Masahiro Sekizawa Yuh Sumioka Masahiro Kawano 《Journal of Materials Processing Technology》2012,212(9):1869-1874
The authors proposed double-layer-type environmentally friendly lubricants, which were composed of an undercoat, superior in adhering to a material, and an overcoat, superior in reducing the friction between the material and the die. The performance of these lubricants for cold forging was evaluated by the ring compression test, the combined forward rod-backward can extrusion-type friction test and the combined forward conical can-backward straight can extrusion-type friction test. The double-layer-type lubricants showed comparable friction characteristics and anti-pick-up properties to a conversion coating lubricant, when the film thickness and surface treatment before coating were improved. In a practical application by cold multistage forging, the double-layer-type lubricants showed a similar performance to a conversion coating lubricant. 相似文献
54.
In [N. Alon, M. Feldman, A.D. Procaccia, M. Tennenholtz, A note on competitive diffusion through social networks, Inform. Process. Lett. 110 (2010) 221–225], the authors introduced a game-theoretic model of diffusion process through a network. They showed a relation between the diameter of a given network and existence of pure Nash equilibria in the game. Theorem 1 of their paper says that a pure Nash equilibrium exists if the diameter is at most two. However, we have an example which does not admit a pure Nash equilibrium even if the diameter is two. Hence we correct the statement of Theorem 1 of their paper. 相似文献
55.
A Method for Reducing the Dead‐Time Voltage and Impedance Voltage in a Series Voltage Compensator 下载免费PDF全文
Atsushi Nakata Masahiro Nozaki Akihiro Torii Akiteru Ueda 《Electrical Engineering in Japan》2014,186(3):85-93
Many research groups are developing series voltage compensators. In a series converter, since a transformer is used in series in the power system, the power system current flows into the voltage source inverter through the transformer. The inverter current, which is determined by the transformation ratio, gives rise to an error voltage that consists of a dead‐time voltage and an impedance voltage. The error voltage is generated even when the reference voltage is zero. This paper describes the mechanism by which the error voltage occurs and proposes a method for reducing the error voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(3): 85–93, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22333 相似文献
56.
Susumu Fujii Masato Yoshiya Akuto Yumura Yohei Miyauchi Masahiro Tada Hideyuki Yasuda 《Journal of Electronic Materials》2014,43(6):1905-1915
The phonon thermal conductivity of misfit-layered Ca3Co4O9 has been calculated by perturbed molecular dynamics using a classical force field. Detailed numerical analyses reveal that, in spite of its smaller cross-sectional area, the CoO2 layer transports more heat than the thicker rock salt (RS) layer, although its local thermal conduction is more suppressed than in another layered cobaltite, Na x CoO2. The origins of these differences have been elucidated through careful examination of the atomic arrangements in each layer. Since thermal conduction in the RS layer can be reduced without deteriorating electronic properties for which the CoO2 layer is responsible, it is suggested that the RS layer should be modified to further suppress the overall in-plane thermal conductivity. Computational experiments with increasing number of Ca–O planes in the RS layer showed the opposite trend to what can be predicted based on the misfit between two dissimilar layers. Further analyses to reveal the origin of these unexpected results provide yet another strategy to further decrease the thermal conductivity, namely to control the dynamic interference between atoms across the interface between two layers. 相似文献
57.
Mohammed Shahien Motohiro Yamada Masahiro Fukumoto 《Journal of Thermal Spray Technology》2016,25(5):851-873
Reactive plasma spraying (RPS) is a promising technology for the in situ formation of several ceramic coatings. The focus of this paper is to summarize the state of our current knowledge about the RPS process and using the nitriding of Al particles and the fabrication of aluminum nitride coatings, as a case study. The aspects and challenges in this process such as the influence of the plasma power, in-flight time, particle size, nitriding mechanism, splat morphology, in-flight particle diagnostics, N2 plasma gas, and the feeding rate on the RPS process are analyzed and discussed. 相似文献
58.
Toshiaki Ozawa Koji Endo Takashi Masui Masahiro Miyaki Keiko Matsuo Shinji Yamada 《Journal of surfactants and detergents》2016,19(4):785-794
Five anionic surfactants widely used in commercial skin cleansers were studied: sodium polyoxyethylene lauryl ether carboxylate (EC), sodium polyoxyethylene alkyl ether sulfate (ES), sodium dodecyl sulfate, potassium laurate, and N-cocoyl-l-glutamic acid monosodium salt. The amount of surfactant from aqueous solution adsorbed into the stratum corneum (SC), the degree of SC swelling, the change of the secondary structure of SC proteins (denaturation). The surface tension of surfactant–zein mixed solutions, and the solubilization behavior of zein were measured. Results showed that EC had the lowest adsorption into SC, the lowest SC swelling, and lowest denaturation of SC proteins. Low interactions between surfactants and SC proteins were also observed for EC/ES mixture solutions as well as. Mixing EC with ES good foaming performance. The EC/ES mixture, at about 1:1 ratio, is an excellent surfactant system for skin cleanser applications having cleansing characteristics and mildness to the skin. 相似文献
59.
This paper reports work on complex formation from ZDP and various aliphatic amines, and their equilibrium states in oil, adsorptivities and antiwear properties are investigated. Complex formation from ZDP and amine was proven by isolation and identification of solid crystals, and various complexes were found from mono- and diamines. The complex from monoamine has lower adsorptivity than free ZDP, while the poorer adsorptivity of ZDP/monoamine complex makes its antiwear property worse. 相似文献
60.
Chiho Miyamaru Mao Koide Nana Kato Shogo Matsubara Masahiro Higuchi 《International journal of molecular sciences》2022,23(2)
We fabricated CaCO3-coated vesicles as drug carriers that release their cargo under a weakly acidic condition. We designed and synthesized a peptide lipid containing the Val-His-Val-Glu-Val-Ser sequence as the hydrophilic part, and with two palmitoyl groups at the N-terminal as the anchor groups of the lipid bilayer membrane. Vesicles embedded with the peptide lipids were prepared. The CaCO3 coating of the vesicle surface was performed by the mineralization induced by the embedded peptide lipid. The peptide lipid produced the mineral source, CO32−, for CaCO3 mineralization through the hydrolysis of urea. We investigated the structure of the obtained CaCO3-coated vesicles using transmission electron microscopy (TEM). The vesicles retained the spherical shapes, even in vacuo. Furthermore, the vesicles had inner spaces that acted as the drug cargo, as observed by the TEM tomographic analysis. The thickness of the CaCO3 shell was estimated as ca. 20 nm. CaCO3-coated vesicles containing hydrophobic or hydrophilic drugs were prepared, and the drug release properties were examined under various pH conditions. The mineralized CaCO3 shell of the vesicle surface was dissolved under a weakly acidic condition, pH 6.0, such as in the neighborhood of cancer tissues. The degradation of the CaCO3 shell induced an effective release of the drugs. Such behavior suggests potential of the CaCO3-coated vesicles as carriers for cancer therapies. 相似文献