Hokkaido University

About: Hokkaido University is a education organization based out in Sapporo, Hokkaidô, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 53925 authors who have published 115403 publications receiving 2651647 citations. The organization is also known as: Hokudai & Hokkaidō daigaku.

Promoting Active Species Generation by Plasmon-Induced Hot-Electron Excitation for Efficient Electrocatalytic Oxygen Evolution

Abstract: Water splitting represents a promising technology for renewable energy conversion and storage, but it is greatly hindered by the kinetically sluggish oxygen evolution reaction (OER). Here, using Au-nanoparticle-decorated Ni(OH)2 nanosheets [Ni(OH)2–Au] as catalysts, we demonstrate that the photon-induced surface plasmon resonance (SPR) excitation on Au nanoparticles could significantly activate the OER catalysis, specifically achieving a more than 4-fold enhanced activity and meanwhile affording a markedly decreased overpotential of 270 mV at the current density of 10 mA cm–2 and a small Tafel slope of 35 mV dec–1 (no iR-correction), which is much better than those of the benchmark IrO2 and RuO2, as well as most Ni-based OER catalysts reported to date. The synergy of the enhanced generation of NiIII/IV active species and the improved charge transfer, both induced by hot-electron excitation on Au nanoparticles, is proposed to account for such a markedly increased activity. The SPR-enhanced OER catalysis co...

Interaction between Clusters and Pauli Principle

Abstract: The Pauli principle characterizes. the relative state between clusters in the overlapping region of them. A theory to clarify the role of the Pauli principle in the interaction be­ tween clusters in a simple way' is proposed. The equation of motion, for the relative state, obtained as a consequence of the total antisymmetrization, excludes naturally the states for­ bidden by the Pauli principle. The relative state is mainly determined by the orthogonality . condition to the forbidden states for the inside and by a local potential for the outside. It is shown that both the characteristic inner oscillation and the almost energy-independent nodes of the relative wave function, which appear in the a:-a: scattering and are interpreted as the origin of the effective repulsive core, are produced by this orthogonality condition. The fea­ tures of the a:-a: scattering are clarified on the basis of the theory proposed.

Epidemiological characteristics of novel coronavirus infection: A statistical analysis of publicly available case data

Abstract: The geographic spread of 2019 novel coronavirus (COVID-19) infections from the epicenter of Wuhan, China, has provided an opportunity to study the natural history of the recently emerged virus. Using publicly available event-date data from the ongoing epidemic, the present study investigated the incubation period and other time intervals that govern the epidemiological dynamics of COVID-19 infections. Our results show that the incubation period falls within the range of 2–14 days with 95% confidence and has a mean of around 5 days when approximated using the best-fit lognormal distribution. The mean time from illness onset to hospital admission (for treatment and/or isolation) was estimated at 3–4 days without truncation and at 5–9 days when right truncated. Based on the 95th percentile estimate of the incubation period, we recommend that the length of quarantine should be at least 14 days. The median time delay of 13 days from illness onset to death (17 days with right truncation) should be considered when estimating the COVID-19 case fatality risk.