The unit for mass, the kilogram, had been the only SI base unit still defined by an artifact. In order to revise the definition, several national metrological institutes had cooperated to measure the Planck constant with an uncertainty better than the mass stability of the artifact. The new definition came into effect on May 20, 2019, the World Metrology Day.
Recently, we have extended the multiple scattering theory (MS) and developed a program to elucidate characteristics of the photoelectron momentum maps (PMMs) from the expanded molecular orbital of the molecular thin films. The PMMs, which are extracted from the angle-resolved photoelectron spectroscopy (ARPES) data are a powerful technique to visualize the interaction between the molecular thin film and the substrate via a reconstruction of molecular orbitals. The calculated PMMs for sample which show the fine structure in the center of PMMs implying an additional influence of the scattering by the substrate are good agreement with experimental results. On the other hand, the result of the simulation based on plane wave approximation (PW) cannot represent the fine structure observed by the extended MS. Furthermore, we can also demonstrate that adsorption positions of organic molecule on the substrate are visualized from the analysis of the PMMs.
We analyzed the lithium-ion battery material LiNi0.5Mn1.5O4 electrode using a portable vacuum transfer vessel. When investigating the chemical state of carbon by X-ray photoelectron spectroscopy, it is important that the battery material is not exposed to the atmosphere. In addition, it was found that when investigating the chemical state of fluorine, it is necessary to analyze not only the effect of the reaction with atmospheric components, but also the deterioration due to irradiation with the X-ray. When the sample is transported in an argon atmosphere for a long time, the oxygen concentration in the transfer vessel increases due to degassing from the sample and the vessel, and the sample surface becomes contaminated.
Oxide semiconductors of elements such as Cu, Ti or Zn are promising for photovoltaic applications. Metal oxides has been fabricated via various wet or dry processes as low cost, non-toxic and chemically stable materials. It had been already found that the photovoltaic powers of Cu2O/TiO2 thin films by reactive magnetron sputtering were affected by the oxygen flow rate during the Cu2O thin film preparation in our investigations.
In this paper, the relationship between the photovoltaic power and the film crystal structure was investigated as a function of the Cu sputtering power or the Cu2O film thickness. The maximum photovoltaic power was obtained at 30 W in the Cu sputtering power. The photovoltaic power and the Cu2O film thickness had no correlation, while the photovoltaic power and the film structure had strong correlation with the peak of Cu2O(111). As a result, the photovoltaic power of Cu2O/TiO2 thin films was affected by the crystallinity of Cu2O.
Recently, we have revealed that the hydrogen boride (HB) sheets can be formed by exfoliation and complete ion-exchange between protons and magnesium cations in magnesium diboride (MgB2＋2H＋ → Mg2＋＋2HB) at room temperature and ambient pressure. We have then found that the hydrogen molecules (H2) can be released from HB by the UV irradiation as much as 8 wt% at room temperature.
Since ion-sensitive field effect transistors (ISFETs) have been developed in 1970, much attention has been focused on FET-based biosensors. In particular, graphene is one of the promising candidates for FET-based biosensors owing to their high electron/hole mobilities and unique 2D nature. Herein, we report specific detection of biomolecules using sialylglycopeptide-modified graphene FET (G-FET) biosensors. In addition, we also present state-space models (SSMs) to analyze time-series data of G-FET biosensors. This computational approach helps to separate the response against target biomolecules from the baseline drifted data. G-FET biosensors open the door to a more versatile sensing platform for biomolecules and biological functions.
We have successfully developed a mass productive sputtering module for insulating materials and advanced PbZrTiO3 (PZT) process technology. PZT films were deposited on 8 inch substrate using mass productive sputtering tool (SME-200 ULVAC inc.). The results obtained in this study are as follows ; (1) As a result that a stable anode was installed, stability of Pb content and deposition rate within film in continuous sputtering (2) Low temperature crystallization of PZT film (＜500℃) by using buffer layer between PZT and bottom Pt electrode (3) High piezoelectric coefficient e31 of －15.5 C/m2 and breakdown voltage of 200 V.
We have manufactured two types of ultra-high vacuum vessels for the gravitational wave observation facility KAGRA. Thirteen containers with an inner diameter of 1500 mm and three containers with an inner diameter of 1200 mm were connected using a bellows unit to achieve an installation accuracy of 2 mm and a gas release rate of 10－8 Pa·m3 s－1 m－2.
Three types of semi-empirical equation for calculating the gas flow rate in a cylindrical tube of arbitrary length-to-diameter ratio are proposed. The solutions of these equations cover all flow regimes from molecular flow to critical flow or subcritical flow via intermediate flow, viscous laminar flow, and turbulent flow. In addition, the calculation procedure is straightforward because it does not require selecting a suitable equation based on the Knudsen number, Reynolds number, and Mach number. Comparing the solutions of the proposed equations with reported results from experiments and computer simulations shows good agreement within 30%.