High-speed High-precision Control of Atomic Force Microscope by Surface Topography Learning Observer

Abstract-Purpose of this paper is realization of high-speed measurement atomic force microscope (AFM) from view point of the control technology without modification of the hardware. Almost commercial AFM, 3D-image is obtained from control input. High-speed imaging is possible if we can design feedback controller which achieves the high-bandwidth servo design. However, we know that it is restricted by bode integral theorem as resonance peak of the plant. For high-speed imaging, our research group proposed surface topography observer which based on the disturbance observer theory. we can locate the pole of the observer without considering of the resonance of the plant. Thus, we succeeded in high-speed imaging by our proposed observer. On the other hand, as the scanning speed of the X scanner becomes faster, the tracking error increases, because the feedback characteristic is same as conventional system. Not only the high-speed imaging but the suppression of the tracking error is important, because the tracking error express the contact force to the sample. Our research group proposed the tracking error suppression methods which are feedforward compensation. This paper describes the dualdirectional type surface topography learning observer. This paper shows our proposed methods which are effective for the high-speed AFM by simulation and experimental results

Spin Injection into a Graphene Thin Film at Room Temperature

We demonstrate spin injection into a graphene thin film with high reliability by using non-local magnetoresistance (MR) measurements, in which the electric current path is completely separated from the spin current path. Using these non-local measurements, an obvious MR effect was observed at room temperature; and the MR effect was ascribed to magnetization reversal of ferromagnetic electrodes. This result is a direct demonstration of spin injection into a graphene thin film. Furthermore, this is the first report of spin injection into molecules at room temperature.Comment: 12 pages, 3 figure

Investigation on River Section Shape Considering Both Spawning Environment of Ayu, Plecoglossus Altivelis, and Flood Control

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

A Nuclear Magnetic Resonance Study on Rubrene-cobalt Nano-composites

We implemented a nuclear magnetic resonance (NMR) study on rubrene(C42H28)-Co nano-composites that exhibit an enhanced magnetoresistance (MR) ratio of 80%. The 59Co NMR spin echo experiment enabled clarification of the hyperfine field of Co at the interface between the ferromagnet and the molecules, which has not been investigated for molecular spintronics. An enhanced hyperfine field of the Co was observed in the rubrene-Co nano-composites, which may be related to the enhancement of the MR ratio. This study demonstrates the importance of microscopic investigation of the interface between molecules and ferromagnets that governs spin-dependent transport in molecular spin devices.Comment: 12pages, 3 figures, 1 tabl

Analysis of Degradation in Graphene-based Spin Valves

The degradation mechanisms of multilayer graphene spin valves are investigated. The spin injection signals in graphene spin valves have been reported to be linearly dependent on the drain bias voltage, which indicates that the spin polarization of injected spins in graphene is robust against the bias voltage. We present that the disappearance of this robustness is due to two different degradation mechanisms of the spin valves. Our findings indicate that the disappearance of the robustness is due to degradation rather than an intrinsic characteristic of graphene. Thus, the robustness can be greatly enhanced if degradation can be prevented.Comment: 14 pages, 4 figures (To appear in Applied Physics Express

One-pot synthesis of imines from alcohols and amines with TiO2 loading Pt nanoparticles under UV irradiation

TiO2 loading Pt nanoparticles (Pt@TiO2) promote one-pot synthesis of imines from alcohols and amines under UV irradiation at room temperature. This is achieved via a Pt-assisted photocatalytic oxidation of alcohols and a catalytic condensation of the formed aldehydes with amines on the TiO2 surface

Identification of glycosylation genes and glycosylated amino acids of flagellin in Pseudomonas syringae pv. tabaci

A glycosylation island is a genetic region required for glycosylation. The glycosylation island of flagellin in Pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. Orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, Delta orf1 and Delta orf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. Digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from Delta orf1 mutant using aspartic N-peptidase and subsequent HPLC analysis revealed candidate glycosylated amino acids. By generation of site-directed Ser/Ala-substituted mutants, all glycosylated amino acid residues were identified at positions 143, 164, 176, 183, 193 and 201. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) analysis revealed that each glycan was about 540 Da. While all glycosylation-defective mutants retained swimming ability, swarming ability was reduced in the Delta orf1, Delta orf2 and Ser/Ala-substituted mutants. All glycosylation mutants were also found to be impaired in the ability to adhere to a polystyrene surface and in the ability to cause disease in tobacco. Based on the predicted tertiary structure of flagellin, S176 and S183 are expected to be located on most external surface of the flagellum. Thus the effect of Ala-substitution of these serines is stronger than that of other serines. These results suggest that glycosylation of flagellin in P. syringae pv. tabaci 6605 is required for bacterial virulence. It is also possible that glycosylation of flagellin may mask elicitor function of flagellin molecule