国内文献検索講習会 (平成18年度)

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100GHz operation of a 4-bit single-flux-quantum pulse-frequency modulator designed for bipolar D/A conversion

We designed and operated a 4-bit single-flux-quantum pulse-frequency modulator for bipolar D/A conversion. It was based on our previously-proposed “sum of selected bit sequence” configuration. Two functions, a synchronization scheme with a reference signal source and a complement number system for realization of bipolar output voltage, were implemented. A test circuit excluding the output analog stage (dual double-flux-quantum amplifier) was fabricated using a 10kA/cm^2 Nb/AlOx/Nb integration process. The synchronization function was evaluated in terms of the average voltages, which agreed well with the expected values. The bipolar D/A conversion was successfully emulated by using the positive and negative output signals. The maximum over-biased input voltage was determined to be 230µV, of which the corresponding SFQ repetition frequency was 111GHz.journal articl

CMP用パッドのコンディショニングに関する基礎的研究

As the basic research for the Pad conditioning by the Diamond Conditioner, relationship between the surface condition of pad, which is ground by the diamond pad conditioner, and the Polishing Rate is investigated. Clogging of the pad surface, the surface conditions achieved by specification of the various pad conditioners and various parameters of the conditioning on the Oxide-CMP Process are correlated.textapplication/pdfdepartmental bulletin pape

On Accuracy Improvement in Surroundings Estimation for Surroundings Adaptable Integrated Authentication Method

At the present time, mobile devices come to be widely used. Since such devices store many kinds of important data, it is necessary to guard the devices using a personal authentication method. On the other hand, higher usability is also needed for such a authentication method. So, is is a hard task to guard mobile devices using a single authentification method. To overcome this problem, the integrated authentication method was proposed in the previous study to adapt multiple situations that have various kinds of requiremnets of security and usebility. However, the method to identify correct situation a device was plaeced was not good enough. In this study, a situation estimation method using GPS was investigated using a simple app developed by the authors and the method showed promise.departmental bulletin pape

Search for matter-dependent atmospheric neutrino oscillations in Super-Kamiokande

We consider ν_μ→ν_τ oscillations in the context of the mass varying neutrino (MaVaN) model, where the neutrino mass can vary depending on the electron density along the flight path of the neutrino. Our analysis assumes a mechanism with dependence only upon the electron density, hence ordinary matter density, of the medium through which the neutrino travels. Fully-contained, partially-contained and upward-going muon atmospheric neutrino data from the Super-Kamiokande detector, taken from the entire SK-I period of 1489 live days, are compared to MaVaN model predictions.We find that, for the case of 2-flavor oscillations, and for the specific models tested, oscillation independent of electron density is favored over density dependence. Assuming maximal mixing, the best-fit case and the densityindependent case do not differ significantly.journal articl

Study of Time-Dependent CP Violation in B0→J/ψπ0 Decays

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Photoelectron Holographic Atomic Arrangement Imaging of Cleaved Bimetal-intercalated Graphite Superconductor Surface

From the C 1s and K 2p photoelectron holograms, we directly reconstructed atomic images of the cleaved surface of a bimetal-intercalated graphite superconductor, (Ca, K)C8, which differed substantially from the expected bulk crystal structure based on x-ray diffraction (XRD) measurements. Graphene atomic images were collected in the in-plane cross sections of the layers 3.3?A and 5.7?A above the photoelectron emitter C atom and the stacking structures were determined as AB- and AA-type, respectively. The intercalant metal atom layer was found between two AA-stacked graphenes. The K atomic image revealing 2?×?2 periodicity, occupying every second centre site of C hexagonal columns, was reconstructed, and the Ca 2p peak intensity in the photoelectron spectra of (Ca, K)C8 from the cleaved surface was less than a few hundredths of the K 2p peak intensity. These observations indicated that cleavage preferentially occurs at the KC8 layers containing no Ca atoms.journal articl