Science Daily February 1, 2019 Sodium ion batteries meet the demand for large-scale energy storage. By investing ~4300 candidates via a high-throughput computation, researchers in Japan have identified nanotube-type Na2V3O7 as a cathode material because of its fast sodium diffusivity. High-rate performance was confirmed, showing ~65% capacity retention at a current density of 10C at room temperature, despite the large particle size of >5 μm. But they found that Na2V3O7 underwent deterioration in the final charging stages, which limits the practical storage capacity to the half of theoretical one. In their future experiments, the researchers aim to focus on improving the […]
Tag Archives: S&T Japan
Computational algorithm to reduce electromagnetic noise in electronic circuits developed
Science Daily January 31, 2019 Researchers in Japan developed algorithm for computer simulation of electric circuits in which transmission lines are connected with lumped element models. They introduced the incidence matrix found in circuit theory and time domain impedance to connect partial differential equations and ordinary differential equations which are used to solve transmission line problems. Based on the results of calculations using this algorithm, the researchers demonstrated that EM noise could be reduced by using the symmetric 3-line configuration of the circuit. Their calculation method is for one-dimensional multi-conductor transmission lines, but they have already developed a calculation algorithm […]
Materials that open in the heat of the moment
Science Daily January 24, 2019 The porous nanomaterials that are currently used for gas separation and storage are not tunable: their pores are persistent and rigid. Researchers in Japan designed a porous coordination polymer with copper atoms linked by butterfly-shaped ligands made from isophthalic acid and phenothiazine-5,5-dioxide. The material was comprised of tiny nanocages with protruding channels. At very low temperatures, the channels were very narrow; as the temperature was increased, the channels opened more and more, allowing gas molecules to move between the cages. A gas could move or become locked within the material depending on the size of […]
Current generation via quantum proton transfer
Nanowerk January 23, 2019 Researchers in Japan have observed quantum tunneling effect in proton-transfer (PT) during potential-induced transformation of dioxygen on a platinum electrode in a low overpotential region at 298 K. This process is converted to the classical PT scheme in the high overpotential region. This observation indicates that the quantum tunneling governs the multistep electron-proton-driven transformation of dioxygen in the low overpotential condition. It shows the involvement of QTE in proton transfer during the basic energy conversion processes. The discovery may facilitate investigations of microscopic mechanisms of electrochemical reactions and stimulate the development of highly efficient electrochemical energy conversion […]
Quantum chemistry on quantum computers
Phys.org January 2, 2019 Among many important and fundamental issues in science, solving the Schroedinger equation (SE) of atoms and molecules is one of the ultimate goals in chemistry, physics and their related fields. Researchers in Japan have found a novel quantum algorithm enabling us to perform full configuration interaction (Full-CI) calculations suitable for “chemical reactions” without exponential/combinatorial explosion. Full-CI gives the exact numerical solutions of SE, which are intractable problems even for supercomputers. Such a quantum algorithm contributes to the acceleration of implementing practical quantum computers…read more. Open Access TECHNICAL ARTICLE
Electronics of the future: A new energy-efficient mechanism using the Rashba effect
Science Daily December 27, 2018 Researchers in Japan using the Rashba effect for generating spin currents in material structures that possess electrons with desirable spin properties. They developed a mechanism to generate a spin current without energy loss from a series of simulations for new quasi-1D materials based on bismuth-adsorbed indium that exhibit a giant Rashba effect. This mechanism does not require an external magnetic field to generate nondissipative spin current. The process would simplify potential spintronic devices and would allow for further miniaturization… read more. Open Access TECHNICAL ARTICLE
World’s first single-panel antenna to simultaneously support multiple 5G communications
Phys.org November 29, 2018 Researchers in Japan have developed technology which delivers high-speed communications in excess of 10 Gbps, as required by 5G mobile communication formats. By controlling the phase of signals separately emitted from 128 antenna elements with high accuracy they have suppressed the interference between signals. This enables simultaneous communications in four directions using only one antenna panel. Signals can be varied in both horizontal and vertical directions expanding the communications area. With these developments, components can now be fit on a single 13 cm2 printed circuit board enabling the deployment of compact base stations and high-speed 5G […]
Making steps toward improved data storage
Phys.org November 7, 2018 Researchers in Japan developed a terahertz pulse generator that delivered ultra-short and highly intense terahertz pulses across a pair of gold antennas. The pulses created an electric field in the material composed of germanium, antimony and tellurium (GST) sample, comparable to that of an electrically switched device. It greatly reduced the heat diffusion because of the extremely short duration of terahertz pulses enabling fine control over the rate and direction of GST crystallization. After a certain point when terahertz pulses were increased, crystal conductivity rapidly sped up instead of rising in line with the increase in […]
Invention of ionic decision-maker capable of self-learning
Eurekalert October 15, 2018 Researchers in Japan have developed a decision-making ionic device capable of operating using electrochemical phenomena induced by the movement of protons within a solid electrolyte. When the device makes a correct decision, ions migrate toward the electrode associated with the decision. They applied this mechanism to a congested radio communication network and succeeded in demonstrating that the device can select an optimum communication channel to be assigned for a given transmission to achieve the most effective overall channel utilization in relation to changing congestion situations and more complex decisions. The invention may lead to the development […]
The future of electronic devices: Strong and self-healing ion gels
Phys.org October 12, 2018 Researchers in Japan have created a polymer gel, called the ion gel, by combining two materials, one is repelled by ionic liquids while the other bonds with hydrogen to form a diblock copolymer. The combination of the liquid salts and the diblock copolymer material resulted in a final micellar structure. Hydrogen bonding is reversible and contributes to a material’s ability to self-heal which can be completed within a few hours. The material has applications in flexible electronics…read more. TECHNICAL ARTICLE