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61.
Hiroki Uehara Takuya Tamura Masaki Kakiage Takeshi Yamanobe 《Advanced functional materials》2012,22(10):2048-2057
Crystalline homopolymers, including polyethylene (PE), which has the simplest architecture, form a nanometer‐sized combination of crystalline and amorphous components, but their arrangement control, similar to self‐assembled phase‐separation of block‐copolymers, is usually difficult. However, molecular entanglements trapped between crystalline and amorphous components of homopolymers coincide with the segmental linking points on the interfaces of the microphase separation for block copolymers. Nanowrinkled PE membranes are prepared with a network of 30 nm‐thick homogeneous lamellae using a novel entanglement control technique composed of biaxial melt‐drawing and melt‐shrinking procedures, which are limited for highly entangled ultrahigh molecular weight materials. Such a network arrangement of nanowrinkling lamellae spreading on membrane surface and also across the membrane thickness improves the mechanical properties of both tensile strength and tearing strength. Subsequent cold‐drawing causes delamination of the lamellar interfaces, leading to the resultant nanoporous morphology composed of passing‐through channels that are several tens of nanometers in diameter, without any solvent processing. 相似文献
62.
Hiroshi Isakari Kazuki Niino Hitoshi Yoshikawa Naoshi Nishimura 《International journal for numerical methods in engineering》2012,90(4):484-505
Preconditioning methods based on Calderon's formulae for the periodic fast multipole method for elastodynamics in 3D are investigated. Three different types of formulations are proposed. The first type is a preconditioning just by appropriately ordering the coefficient matrix without multiplying preconditioners. The other two types utilise preconditioners constructed using matrices needed in the main fast multipole method algorithms. We make several numerical experiments with proposed preconditioners to confirm the efficiency of these proposed methods. We also conclude that the preconditioning of the first type is faster with respect to the computational time than other preconditioning methods discussed in this article. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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64.
Motoyuki Karita Koji Asaka Hitoshi Nakahara Yahachi Saito 《Journal of Materials Science》2013,48(2):936-940
Electrical conductance of multi-walled carbon nanotubes (MWCNTs) with closed and open tips contacting with a gold (Au) electrode was studied by in situ transmission electron microscopy. When a current density through the contact region reached a threshold value of 2.6 × 108 A/cm2, the MWCNT tip was embedded into the Au surface by local melting of Au, and the total resistance was reduced with the increase of the contact area. Conductance per unit area at the contact between the MWCNT and Au electrode for the open-ended MWCNT is four times larger than that for the close-ended one, which is due to the direct connection of inner walls of the open-ended MWCNT with the Au surface. 相似文献
65.
Mohammad Abul Hossain Shahidul Islam Farzana A. Chowdhury Tariq G. Mohiuddin Koji Uchida Takahiro Tamura 《Fullerenes, Nanotubes and Carbon Nanostructures》2016,24(1):43-51
We studied the elemental analysis, structural morphology, mechanical, and electrical properties of carbon nanoparticles synthesized from diesel. The spherical carbon particle size in the range of about 10 to 80 nm in diameter was observed in scanning electron microscope (SEM) studies that were identified by Atomic force microscopy (AFM) study as an aggregation of carbon particles of average size 2.5 nm. The surface rms of carbon nanoparticle thin film (CNTF) was measured directly by AFM and found 0.22 nm. The Derjaguin–Muller–Toporov (DMT) elastic modulus of carbon nanoparticles (CNPs) was measured by PeakForce QNM mode of AFM. The minimum and maximum elastic modulus was measured of 0.40 GPa and 43.89 GPa, respectively. The resistivity, conductivity, magneto resistance, mobility, and average Hall co-efficient were measured by “Ecopia Hall-effect measurement system” by four-point Van der Pauw approach at ambient condition. We demonstrated I–V characteristic at the Indium/CNTF thin film interface, which is accompanied by rectifying behavior. 相似文献
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67.
Shiro Yano Yusuke Ikemoto Hitoshi Aonuma Hajime Asama 《Robotics and Autonomous Systems》2012,60(5):722-728
It is thought that the adjustment of intraspecific aggression is an essential factor in the development of a social structure. To understand the natural laws for organizing the social structure, we focus on the fighting behavior of crickets, Gryllus bimaculatus, and investigate the neuronal mechanisms to adjust aggressiveness associated with a neuromodulatory biological amine: serotonin (5-HT).In this paper, we present a working theory of a neurophysiological mechanism based on the past biological studies on the 5-HT hypothesis, and a mathematical model of the mechanism. We analyzed this model and concluded that this neurophysiological mechanism makes the forgetting process slower. Next, we fitted our theoretical forgetting curve to an experimental curve and estimated the parameters of our model. These estimated values were in agreement with common belief in biological science. 相似文献
68.
Jitendra Kumar Pandey Hitoshi Takagi Antonio Norio Nakagaito Daulat Ram Saini Sung-Hoon Ahn 《Composites Part B》2012,43(7):2822-2826
Biopolymer based composites have been employed in numerous applications with increasing interest not only due to renewable, eco-friendly nature, but also because of the flexibility in processing conditions and competitive cost of their end products. The conductive materials from biopolymers have been found applicable in robots, medical imaging, sensitive membranes, actuators, visual displays, electronic wiring and shielding, and components in batteries. Cellulose is one of the most abundant biopolymers in the nature, which has received special attention for development of conducting materials due to biocompatibility for protein and drug immobilization and ability to form the composites with synthetic polymers. The present review is aimed to provide concisely the current status in this field of conducting composites from cellulose, with brief discussions of associated problems and future applications. 相似文献
69.
Hui Zhang Yahia A. Alhamed Abdulrahim Al-Zahrani Mohammad Daous Hitoshi Inokawa Yoshitsugu Kojima Lachezar A. Petrov 《International Journal of Hydrogen Energy》2014
Multi-walled carbon nanotubes, three types of activated carbons, single wall carbon nanotube and reduced graphene oxides were used to synthesize nano-sized Co catalysts for H2 preparation via NH3 decomposition. Catalyst samples were characterized by number of techniques such as N2 physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopes (XPS), Transmission electron microscopy (TEM), CO chemisorption, temperature-programmed reduction (H2-TPR) and temperature-programmed desorption (N2-TPD). The catalytic activities of the studied catalysts for H2 production via NH3 decomposition were measured in a fixed-bed micro-reactor. Co catalyst supported on multi-wall carbon nanotubes has shown the highest catalytic activity. The Co particles size was significantly affected by the variation of the post-treatment temperature. The Co particles size in the range of 4.7–64.8 nm can be effectively controlled by varying post-treatment temperature between 230 and 700 °C. The maximum TOF of NH3 decomposition was registered on cobalt catalyst post-treated at 600 °C. 相似文献
70.