Engineering

29 Arima, K. ; Katoh, J.; Horie, S.; Endo, K.; Ono, T. .; Sugawa, S.; Akahori, H.; Teramoto, A.; Ohmi, T.
(Graduate School of Engineering)
Hydrogen Termination of Si(110) Surfaces upon Wet Cleaning Revealed by Highly Resolved Scanning Tunneling Microscopy
Journal of Applied Physics, 98, 103525/1-8 (2005)

Si(110) surfaces have attracted a great deal of attention from both physical and technological viewpoints. This paper reports on atomic-scale structures of H-saturated Si(110) surfaces after wet cleaning by means of scanning tunneling microscopy. When a surface oxide layer is stripped using a HF-containing solution, the surface consists of nanometer-scaled terraces and atomic steps. The Si(110) surface after subsequent rinsing for a short period is occupied by a long terrace in which coupled monohydride structures are formed.


30 Doi, S. ; Kumagai, S.
(Graduate School of Engineering)
Generation of Very Slow Neuronal Rhythms and Chaos Near the Hopf Bifurcation in Single Neuron Models
Journal of Computational Neuroscience, 19, 325-356 (2005)

Neurons are classified into Type-I and Type-II neurons by their generation mechanism of spikes. This classification is important since it is essentially related to information processing in brain. This paper raises a serious question about the longtime believed classification and shows that the classification is meaningless; Type-II neurons behave as Type-I neurons under a generic condition. This paper also raises an important mathematical problem: homoclinic orbits and chaos can be generated near a Hopf bifurcation under a very general condition.


31 Lu, S.; Fujii, H. ; Nogi, K.
(Joining and Welding Research Institute)
Influence of Welding Parameters and Shielding Gas Composition on GTA Weld Shape
ISIJ International, 45, 66-70 (2005)


32 Fujioka, S. ; Nishimura, H.; Nishihara, K.; Sasaki, A.; Sunahara, A.; Okuno, T.; Ueda, N.; Ando, T.; Tao, Y.: Shimada, Y.; Hashimoto, K.; Yamaura, M.: Shigemori, K.; Nakai, M.; Nagai, K.; Norimatsu, T.; Nishikawa, T.; Miyanaga, N.; Izawa, Y.; Mima, K.
(Institute of Laser Engineering)
Opacity Effect on Extreme Ultraviolet Radiation from Laser-Produced Tin Plasmas
Physical Review Letters, 95, 235004/1-4 (2005)


33 Kitaguchi, H.; Ohkubo, K.; Ogo, S.; Fukuzumi, S.
(Graduate School of Engineering)
Lipid Peroxidation: Mechanistic Insight into Regioselective Oxygenation in Lipoxygenases
Journal of the American Chemical Society, 127, 6605-6609 (2005)

Pentadienyl radicals and subsequent peroxyl radicals in lipid peroxidation have been successfully detected by ESR, indicating the preferable addition of O 2 at the C-11 position of free pentadienyl radical derived from linoleic acid, where the spin density is the largest. This finding supports an idea of O 2 entering via a specific protein channel which determines the stereo- and regiochemistry of the biradical combination between O 2 and linoleyl radical in lipoxygenases.


34 Hagihara, K. ; Tanaka, T.; Nakano, T.; Umakoshi, Y.
(Graduate School of Engineering)
Plastic Deformation Behavior of Ni 3 (Ti 0.90 Nb 0.10 ) Single Crystals with the Nine-Layered Ordered Rhombohedral Structure
Acta Materialia, 53, 5051-5059 (2005)

In this paper, the criterion for the occurrence of the yield stress anomaly (YSA) in the geometrically close-packed (GCP) compounds was investigated using the Ni 3 (Ti 0.90 Nb 0.10 ) single crystals with rhombohedral crystal symmetry. We found that the strong YSA appears by slip on {111} 110 , demonstrating that the YSA by the Kear-Wilsdorf locking mechanism occurs not only in the simple GCP compounds with fcc or hcp unit cell, but also in other complex compounds with long stacking sequence of a close-packed plane.


35 Ogi, H.; Niho, H.; Hirao, M.
(Graduate School of Engineering Science)
Internal-Friction Mapping on Solids by Resonance Ultrasound Microscopy
Applied Physics Letters, 88, 141110/1-3 (2006)

Non-contacting measurement of the resonance frequency and attenuation coefficient of the longitudinal vibration of an isolated langasite oscillator, point-contacting the material, has been achieved with a line antenna, providing high sensitivity to the modulus and damping in the local surface area. Formulation of the relationship between material’s local internal friction and attenuation of the resonator system is proposed using a generalized Hertzian-contact model. Results on a dual-phase stainless steel and a Cu/NbTi composite are shown.


36 Fujii, H.; Sakurai, H. *1, 2; Tani, K. *2; Wakisaka, K.; Hirao, T. *1,2
*1(Graduate School of Engineering)
*2(Frontier Research Center, Graduate School of Engineering)
Bright and Ultimately Pure Red Electrophosphorescent Diode Bearing Diphenylquinoxaline
IEICE Electronics Express, 2, 260-265 (2005)

The ultimately pure red OLED using new electrophosphorescent compound, bis(2,3-diphenylquinoxaline)iridium(acetylacetonate) [(QH) 2 Ir(acac)] is described. Electrophosphorescence peak wavelength and bandwidth were advanced for the purest red color stimulus to 680 nm with full width at half maximum of 89 nm by doping (QH) 2 Ir(acac) into a light emitting electron transport layer composed of 3-(4-biphenylyl)-4-phenyl-5-(4- tert -butylphenyl) -1,2,4-triazole. The most vivid red electrophosphorescence with CIE chromaticity coordinates better than x=0.70 and y=0.28 was attained and maintained even in luminance brighter than 600 cd/m 2 .


37 Ide, E.; Angata, S.; Hirose, A. ; Kobayashi, K. F.
(Graduate School of Engineering)
Metal-Metal Bonding Process Using Ag Metallo-Organic Nanoparticles
Acta Materialia, 53, 2385-2393 (2005)

A novel bonding process using Ag metallo-organic nanoparticles has been proposed. At a low bonding temperature of 573 K under a bonding pressure of 1 or 5 MPa, Cu-to-Cu joining using the Ag nanoparticles, of which shear strength was 25-40MPa, was achieved. Metallurgical bonding could be realized at the interface between the Cu and the Ag layer sintered with Ag nanoparticles. This bonding is suggested to originate from the large surface energy contribution caused by the nano-size particles.


38 Takahara, Y. K. *1; Ikeda, S. *2; Tachi, K. *1; Sakata, T. *3; Hasegawa, T. *3; Mori, H. *3; Matsumura, M. *2; Ohtani, B.
*1 (Graduate School of Engineering Science)
*2 (Research Center for Solar Energy Chemistry)
*3 (Research Center for Ultra-High Voltage Electron Microscopy)
Porous Polystyrene Microspheres Having Dimpled Surface Structures Prepared within Micellar Assemblies of Amphiphilic Silica Particles in Water
Chemical Communications, 4205-4207 (2005)

Productions of porous polystyrene (PS) microspheres having dimpled surface structures were demonstrated using amphiphilic and hydrophobic silica particles. Direct observations of precursor composites and PS microspheres using scanning electron microscopy (SEM) revealed that the amphiphilic particles act as a template to form spherical materials with a dimpled surface and that the hydrophobic ones act as a template to form meso- and/or macro- porous structures. The microspheres thus-obtained should have potential applications in catalysts and adsorbents.


39 Toyofuku, M. ; Fujiwara, S.-I.; Shin-ike, T.; Kuniyasu, H.; Kambe, N.
(Graduate School of Engineering)
Palladium-Catalyzed Intramolecular Selenocarbamoylation of Alkynes with Carbamoselenoates: Formation of α-Alkylidene-β-lactam Framework
Journal of the American Chemical Society, 127, 9706-9707 (2005)

β-Lactams are a group of compounds having a 4-membered cyclic amide skeleton which appear in some natural products possessing antibiotic activities. The present study revealed that Pd(PPh 3 ) 4 catalyzes the addition of carbomoselenoates to terminal alkynes affording a β-seleno acrylamides by intermolecular selenocarbamoylation. This catalytic system can successfully be applied to intramolecular systems and a convenient method for the synthesis of α-alkylidene β-lactams carrying seleno and thio group on the exo methylene carbon has been developed.
1 of 4 Forward
share !