Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

Recent advances in the chemistry of magnesium carbenoids.

Abstract: This tutorial review deals with recent advances in the chemistry and synthetic use of magnesium carbenoids. The reactivity of traditional carbenoids (α-haloalkyllithium species) was successfully reduced by using magnesium as the metal instead of lithium. Properties of these relatively stable carbenoids, magnesium carbenoids, were widely investigated and it was found that the magnesium carbenoids have very interesting reactivity toward several nucleophiles. The magnesium carbenoids, magnesium cyclopropylidenes, magnesium alkylidene carbenoids, and magnesium β-oxido carbenoids are generated from α-chloroalkyl (or α-chloroalkenyl) aryl sulfoxides with a Grignard reagent at low temperature by sulfoxide–magnesium exchange reaction. The stability of the generated magnesium carbenoids and several new reactions based on the electrophilicity of the magnesium carbenoids, including 1,3-CH insertion, are reviewed. Magnesium carbenoids open up the new world of the chemistry of carbenoids.

Mesoporous TiO2 core-shell spheres composed of nanocrystals with exposed high-energy facets: facile synthesis and formation mechanism.

Abstract: A facile new method that combines electrospray and hydrothermal treatment is used to prepare mesoporous core–shell TiO2 spheres with high specific surface areas and high pore volumes. Interestingly, the resulting TiO2 spheres are composed of anatase TiO2 nanocrystals with exposed step-like {001} and smooth {010} facets. The percentage of exposed {001} facets can be adjusted by changing the experimental parameters used in the electrospray and hydrothermal treatment processes, such as the contents of poly(N-vinyl-2-pyrrolidone) and acetic acid. The combination of high specific surface area (>100 m2 g–1), high pore volume (>0.30 cm3 g–1), useful pore size (10–15 nm), spherical core–shell structure, and exposed high energy facets makes these TiO2 spheres an important candidate for use in many photoelectrochemical applications. The formation mechanism of the mesoporous TiO2 spheres is also studied. The great advantage of this method is that interesting and complicated mesoporous superstructures can be prepared...

Non-orthogonal access with SIC in cellular downlink for user fairness enhancement

Abstract: This paper investigates the enhancement of cell-edge user throughput by using non-orthogonal access with a successive interference canceller (SIC) in the cellular downlink compared to orthogonal access, which is widely used in 3.9 and 4G mobile communication systems. Since both the total user throughput and cell-edge user throughput are important in a real system, we compare the cell-edge user throughput while subject to the same total user throughput. The optimum resource allocation in terms of bandwidth and transmission power for each user is assumed for the respective access schemes based on the instantaneous channel conditions. The evaluation results show that non-orthogonal access with a SIC significantly enhances the cell-edge user throughput (thus user fairness) compared to orthogonal access while achieving the same total user throughput in the context of the cellular downlink, which can yield some insights regarding the direction of the wireless access scheme for the systems beyond IMT-Advanced.

Polyanionic Compounds for Potassium-Ion Batteries.

Abstract: Lithium-ion batteries have the highest energy density among practical secondary batteries and are widely used for electronic devices, electric vehicles, and even stationary energy-storage systems. Along with the expansion of demand and applications, the concern about resources of lithium and cobalt is growing. Therefore, secondary batteries composed of abundant elements are required to complement lithium-ion batteries. In recent years, the development of potassium-ion batteries has attracted much attention, especially for large-scale energy storage. In order to realize potassium-ion batteries, various compounds are proposed and investigated as positive electrode materials, including layered transition-metal oxides, Prussian blue analogues, and polyanionic compounds. This article offers a review of polyanionic compounds which are typically composed of abundant elements and expected high operating potential. Furthermore, we deliver our new results to partially compensate for lack of studies and provide a future perspective.