National Institute of Advanced Industrial Science and Technology

About: National Institute of Advanced Industrial Science and Technology is a government organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 22114 authors who have published 65856 publications receiving 1669827 citations. The organization is also known as: Sangyō Gijutsu Sōgō Kenkyū-sho.

Morphological change and mobility enhancement in PEDOT:PSS by adding co-solvents.

Abstract: Adding ethylene glycol (EG) to a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution improves the crystallinity of the PEDOT and the ordering of the PEDOT nanocrystals in solid films. The carrier-mobility enhancement is confirmed by using ion-gel transistors combined with in situ UV-vis-NIR spectroscopy.

Vowel recognition with four coupled spin-torque nano-oscillators

Abstract: In recent years, artificial neural networks have become the flagship algorithm of artificial intelligence1. In these systems, neuron activation functions are static, and computing is achieved through standard arithmetic operations. By contrast, a prominent branch of neuroinspired computing embraces the dynamical nature of the brain and proposes to endow each component of a neural network with dynamical functionality, such as oscillations, and to rely on emergent physical phenomena, such as synchronization2–6, for solving complex problems with small networks7–11. This approach is especially interesting for hardware implementations, because emerging nanoelectronic devices can provide compact and energy-efficient nonlinear auto-oscillators that mimic the periodic spiking activity of biological neurons12–16. The dynamical couplings between oscillators can then be used to mediate the synaptic communication between the artificial neurons. One challenge for using nanodevices in this way is to achieve learning, which requires fine control and tuning of their coupled oscillations17; the dynamical features of nanodevices can be difficult to control and prone to noise and variability18. Here we show that the outstanding tunability of spintronic nano-oscillators—that is, the possibility of accurately controlling their frequency across a wide range, through electrical current and magnetic field—can be used to address this challenge. We successfully train a hardware network of four spin-torque nano-oscillators to recognize spoken vowels by tuning their frequencies according to an automatic real-time learning rule. We show that the high experimental recognition rates stem from the ability of these oscillators to synchronize. Our results demonstrate that non-trivial pattern classification tasks can be achieved with small hardware neural networks by endowing them with nonlinear dynamical features such as oscillations and synchronization. A network of four spin-torque nano-oscillators can be trained in real time to recognize spoken vowels, in a simple and scalable approach that could be exploited for large-scale neural networks.

Efficient projector expansion for the ab initio LCAO method

Abstract: A projector expansion method is presented for an efficient and accurate implementation of the first-principles electronic structure calculations using pseudopotentials and atomic basis functions. By expressing the rapidly varying local potential in the vicinity of nuclei by a separable projector expansion, the difficulty involved in the grid integration using the regular real-space grid is remarkably reduced without increasing the computational effort. To illustrate the capability, it is shown that the proposed method significantly suppresses not only a spurious oscillation in the energy curve for the atomic displacement involved in a weak interaction such as hydrogen bonding, but also the dependence of optimized structure on relative position to the real-space grid in the geometry optimization within a modest grid fineness.

Aerobic Oxidation of Cyclohexane Catalyzed by Size-Controlled Au Clusters on Hydroxyapatite: Size Effect in the Sub-2 nm Regime

Abstract: In this work, we synthesized gold clusters, Aun (n = 10, 18, 25, 39), with atomically controlled sizes on hydroxyapatite (HAP) and studied the catalysis for aerobic oxidation of cyclohexane. These Aun/HAP catalysts could efficiently oxidize cyclohexane to cyclohexanol and cyclohexanone. The turnover frequency monotonically increased with an increase in the size, reaching values as high as 18 500 h−1 Au atom−1 at n = 39, and thereafter decreased with a further increase in n up to n ∼ 85. This finding provides a fundamental insight into size-specific catalysis of gold in the cluster regime (diameter < 2 nm) and a guiding principle for rational design of Au cluster-based catalysts.