Tokyo Institute of Technology

About: Tokyo Institute of Technology is a education organization based out in Tokyo, Tôkyô, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 46775 authors who have published 101656 publications receiving 2357893 citations. The organization is also known as: Tokyo Tech & Tokodai.

Ground-motion characteristics estimated from spectral ratio between horizontal and vertical components of microtremor

Abstract: The spectral ratio between horizontal and vertical components (H/V ra- tio) of microtremors measured at the ground surface has been used to estimate fun- damental periods and amplification factors of a site, although this technique lacks theoretical background. The aim of this article is to formulate the H/V technique in terms of the characteristics of Rayleigh and Love waves, and to contribute to improve the technique. The improvement includes use of not only peaks but also troughs in the H/V ratio for reliable estimation of the period and use of a newly proposed smoothing function for better estimation of the amplification factor. The formulation leads to a simple formula for the amplification factor expressed with the H/V ratio. With microtremor data measured at 546 junior high schools in 23 wards of Tokyo, the improved technique is applied to mapping site periods and amplification factors in the area. mode Rayleigh waves. Mainly based on these facts, in this study, a large proportion of microtremors are thought to con- sist of surface waves, mainly of their fundamental modes. This article first deals with the peak period in the H/V ratio of microtremors and its relation to the fundamental pe- riod of the response to vertically incident S waves. Next, peak values in the H/V ratio are related to the amplification factors for the S waves. In this process, a new smoothing function is proposed for getting a better correlation between them. A simple relation between the amplification factor and the H/V ratio, which is similar to a so-called Nakamura's method, is also formulated. Finally, the periods and the am- plification factors estimated from microtremor measurement at 546 stations in Tokyo are mapped as a demonstration of practicality of the present study.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

Abstract: In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Atomic Control of the SrTiO3 Crystal Surface

Abstract: The atomically smooth SrTiO3 (100) with steps one unit cell in height was obtained by treating the crystal surface with a pH-controlled NH4F-HF solution. The homoepitaxy of SrTiO3 film on the crystal surface proceeds in a perfect layer-by-layer mode as verified by reflection high-energy electron diffraction and atomic force microscopy. Ion scattering spectroscopy revealed that the TiO2 atomic plane terminated the as-treated clean surface and that the terminating atomic layer could be tuned to the SrO atomic plane by homooepitaxial growth. This technology provides a well-defined substrate surface for atomically regulated epitaxial growth of such perovskite oxide films as YBa2Cu3O7-δ.

Amorphous transparent conductive oxide InGaO3(ZnO)m (m≤ 4): a Zn4s conductor

Abstract: With the purpose of creating ZnO-based amorphous transparent conductors, a range of amorphous films InGaoO3(ZnO)m (where m ≤ 4) was prepared using a pulsed-laser deposition method. The resulting films exhibited an optical bandgap of 2.8-3.0 eV, and an n-type electric conductivity of 170-400 Scm−1 at room temperature, displaying a slight dependence on the value of m, in which the carrier density was 1019-1020 cm−3 the electron mobili ty was 12-20 cm2 V−1 s−1 showing no p n anomaly between Hall and Seebeck coefficients. The conductivity displayed no significant dependence on the temperature ranging from 10 to 300 K. X-ray diffraction, transmission electron microscopy and extended X-ray absorption fine structure measurements confirmed that the films were amorphous phases. A combined use of bremsstrahlung isochromat spectroscopy and ultraviolet photoelectron spectroscopy revealed that the conduction band tail had a large dispersion and that the Fermi level was located at the conduction band edge. The...

Critical exponents of the dielectric constants in diffused-phase-transition crystals

Abstract: The critical exponent γ in the relation between the dielectric constant and temperature (1/e—1/em = C'-1x (T—Tm)γ) has been determined precisely for relaxor ferroelectrlics Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3 Nb2/3)O3 and a related solid solution 0.88Pb (Zn1/3 Nb2/3)O3-0. I2PbT103, as well as for normal ferroelectrics BaTiO3 and K(Ta0. 55Nb0.45)O3. A high correlation of the γ value with the plase transition diffuseness has been found empirically. Moreover, this γ value is very close to another critical exponent γ* which is defined in the relation between the dielectric constant and hydrostatic pressure (1/e—1/em = C* (p—pm)γ*)