Matsuoka R.,University of Tokyo |
Matsuoka R.,Japan Society for the Promotion of Science |
Sakamoto R.,University of Tokyo |
Hoshiko K.,University of Tokyo |
And 6 more authors.
Journal of the American Chemical Society | Year: 2017
Synthetic two-dimensional polymers, or bottom-up nanosheets, are ultrathin polymeric frameworks with in-plane periodicity. They can be synthesized in a direct, bottom-up fashion using atomic, ionic, or molecular components. However, few are based on carbon-carbon bond formation, which means that there is a potential new field of investigation into these fundamentally important chemical bonds. Here, we describe the bottom-up synthesis of all-carbon, π-conjugated graphdiyne nanosheets. A liquid/liquid interfacial protocol involves layering a dichloromethane solution of hexaethynylbenzene on an aqueous layer containing a copper catalyst at room temperature. A multilayer graphdiyne (thickness, 24 nm; domain size, >25 μm) emerges through a successive alkyne-alkyne homocoupling reaction at the interface. A gas/liquid interfacial synthesis is more successful. Sprinkling a very small amount of hexaethynylbenzene in a mixture of dichloromethane and toluene onto the surface of the aqueous phase at room temperature generated single-crystalline graphdiyne nanosheets, which feature regular hexagonal domains, a lower degree of oxygenation, and uniform thickness (3.0 nm) and lateral size (1.5 μm). © 2017 American Chemical Society.
News Article | April 20, 2016
Abstract: Conventional 3D displays, such as stereo displays with glasses and glass-free autostereoscopic displays, show two-dimensional images for each eye. Therefore, users experience incongruity and eyestrain owing to these pseudo-3D images. A holographic display produces an exact copy of the wave front of scattered light from an object, and hence, a realistic 3D display is expected. Holographic displays can reconstruct realistic 3D images, thereby eliminating the need for special glasses. However, construction of holographic displays is difficult, as nano-sized pixels are required for reconstructing 3D images with a wide viewing-angle. Conventional holographic displays have a viewing angle of Researchers at Toyohashi Tech have recently developed wide-viewing 3D holographic displays composed of nano-magnetic pixels. These displays are driven by thermomagnetic recordings, and wide viewing-angles are achieved through the use of in-house-developed magneto-optic spatial light modulators (MOSLMs) composed of nano-sized pixels. According to Associate Prof. Takagi, "The advantages of this approach are that the focused spot of a laser defines the pixel size, the MOSLM does not require special current or voltage drivelines, and the switching speed is about 10 nsec/pixel that is enough for real-time display. Therefore, the MOSLM can represent 3D movie because display media is a rewritable magnetic material. In addition, the magnetic hologram is stored for magnetic materials semi permanently. The viewing angle depends on pixel pitch size. In this study, we adjusted to the pixel pitch size of 1 μm after obtaining the pixel size of 1 µm." This confirms, as previously stated, that a 3D display with 1-µm-pitch pixels can display holographic images at a viewing angles of over 30°. Therefore, this display constitutes an attractive option for visualizing 3D objects with a smooth motion parallax and without special glasses. ### Funding agency: This work was supported by JSPS KAKENHI Grant Numbers 26220902, 25820124, 15J05710, and SCOPE (152106003). T.G. acknowledges JSPS KAKENHI No. 26706009, and JST PRESTO. About Toyohashi University of Technology Toyohashi University of Technology, which was founded in 1976 as a National University of Japan, is a leading research institute in the fields of mechanical engineering, advanced electronics, information sciences, life sciences, and architecture. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Okabe M.,University of Electro - Communications |
Anjyo K.,Japan Science and Technology Agency |
Onai R.,JST PRESTO
Proceedings - Digital Production Symposium 2012, DigiPro 2012 | Year: 2012
We propose a method to extract fluids from a video that is captured outside a special studio. Since such a video usually has a complex background and the fluids overlap with much transparency, it is a difficult, time-consuming task for a designer to extract them. Our goal is to develop an efficient method to solve the problem: we estimate the background of an input video, and then compute the foreground and alpha matte at each frame. Our method estimates the background by observing only pixels that have little motion at each frame. Given the estimated background, we estimate an initial alpha matte based on the color difference at every pixel between each frame and the estimated background. Since the initial alpha matte usually includes many artifacts, we employ the gradient-domain image processing approach to refine it: our method attenuates unrequired gradients adequately, and then integrate them to recover the refined alpha matte. The foreground, which explains about the color and texture pattern of the fluid itself, is also estimated in a similar manner. We demonstrate that our method enables to extract the fluids from a video, which were difficult to achieve using the previous methods. Copyright © 2012 by the Association for Computing Machinery, Inc.
Duan P.,Kyushu University |
Yanai N.,Kyushu University |
Kurashige Y.,JST PRESTO |
Kurashige Y.,Japan Institute for Molecular Science |
And 2 more authors.
Angewandte Chemie - International Edition | Year: 2015
Aggregation-induced photon upconversion (iPUC) based on control of the triplet energy landscape is demonstrated for the first time. When a triplet state of a cyano-substituted 1,4-distyrylbenzene derivative is sensitized in solution, no upconverted emission based on triplet-triplet annihilation (TTA) was observed. In stark contrast, crystalline solids obtained by drying the solution revealed clear upconverted emission. Theoretical studies unveiled an underlying switching mechanism: the excited triplets in solution immediately decay back to the ground state through conformational twisting around a C-C bond and photoisomerization, whereas this deactivation path is effectively inhibited in the solid state. The finding of iPUC phenomena highlights the importance of controlling excited energy landscapes in condensed molecular systems. Affairs of state: Whereas a cyano-substituted 1,4-distyrylbenzene derivative shows no upconverted (UC) emission in solution, a clear upconverted emission is observed for solution-cast crystals (see picture). The difference is attributed to immediate decay of excited triplets through conformational twisting and isomerization being possible in solution but not in the solid state. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Hagiwara M.,Nagoya University |
Kawahara T.,Nagoya University |
Feng L.,Tohoku University |
Yamanishi Y.,JST PRESTO |
Arai F.,Nagoya University
Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) | Year: 2011
This paper presents innovative driving method for the magnetically driven microtool (MMT) which is actuated in a microfluidic chip by permanent magnets on the XY stage. A piezoelectric ceramic is applied to induce ultrasonic vibration to the microfluidic chip and the high-frequency vibration reduces the effective friction on the MMT significantly. As a result, we achieved 1.1 micrometer positioning accuracy of the MMT, which is 100 times higher accuracy than without vibration. The enucleation process has been conducted inside the microfluidic chip by this precisely controlled MMT and we achieved to remove nucleus from swine oocytes in high speed.
Oishi-Tomiyasu R.,JST PRESTO |
Oishi-Tomiyasu R.,Tohoku University
Acta Crystallographica Section A: Foundations and Advances | Year: 2016
Geometrical ambiguity means the cases in which more than one powder indexing solution exists. Using a new function implemented in the powder indexing software CONOGRAPH, unit cells that involve geometrical ambiguity are exhaustively searched. As a result, many unknown cases are obtained, although the number of such unit cells is still rather limited. It is also proven that the number of solutions in powder auto-indexing is not always unique, but generally finite. © 2016 International Union of Crystallography.
Ie Y.,Osaka University |
Ueta M.,Osaka University |
Nitani M.,Osaka University |
Tohnai N.,JST PRESTO |
And 4 more authors.
Chemistry of Materials | Year: 2015
4,9-Dihydro-s-indaceno[1,2-b:5,6-b′]dithiazole-4,9-dione (IDD) was designed as a novel electronegative unit, and the π-conjugated compound (2C-TzPhTz) containing it was synthesized as a candidate for air-stable n-type organic field-effect transistor (OFET) materials. Cyclic voltammetry measurements revealed that the IDD unit contributes to lowering the lowest unoccupied molecular orbital (LUMO) energy level. X-ray crystallographic analysis of 2C-TzPhTz showed an almost planar molecular geometry and dense molecular packing, which is advantageous to electron transport. OFETs based on 2C-TzPhTz showed high electron mobility of up to 0.39 cm2 V-1 s-1, which is one of the highest electron mobilities observed among pentacyclic dione-based materials. Top-contact OFET devices showed operating stability and long-term stability under ambient conditions, attributed to the low-lying LUMO energy level and dense packing in the solid state. Furthermore, bottom-contact OFETs also maintained good electron mobility beyond 0.1 cm2 V-1 s-1 under air-exposed conditions. We demonstrated that n-type OFETs are more sensitive to H2O than O2 and found that the acquirement of air stability for the 2C-TzPhTz-based OFET is due to the increased stability against not only O2 but also H2O. All of these results indicate that IDD is a potentially useful building unit for high-performance air-stable n-type semiconducting materials. © 2012 American Chemical Society.
Kurihara K.,Japan National Institute of Advanced Industrial Science and Technology |
Tsukada K.,JST PRESTO
Communications in Computer and Information Science | Year: 2013
Freedom of expression is welcomed in democratic nations, but there is no end of cases in which recorded video is processed to report information not intended by the person in the video. For this article, we have developed a prototype system for preventing this sort of bias in reporting. The system is a smartphone application that allows users, who are the subject of news-gathering, to also record the material themselves, post it to a video sharing site, and to display a QR code containing a link to the video. The system enables a link to a video reproducing the original statements to be forcefully embedded in the report video, which should inhibit bias in the reporting as it is presented later. © Springer-Verlag Berlin Heidelberg 2013.
Osawa H.,JST PRESTO |
Yamada S.,Japan National Institute of Information and Communications Technology
Artificial Life and Robotics | Year: 2011
This article considers what kind of partial agency can be implemented for objects to bring about better agencies for interacting with humans. We humans have the ability to inform our fellows about our intentions, internal states, and requirements through verbal means, gestures, attitudes, timings, and other representations. These representations help us to maintain our belief that we are sufficient agents. Robots and virtual agents also mimic these representations; they act as if they have such an agency. However, their agencies are sometimes too excessive compared to their task. This mismatch leads to a high cognitive load being placed on users and consequently leads to breakdowns in interaction; it prevents human-agent interaction from being a modality in certain applications. We have devised an agency with multiple selectable features. We believe that selectable features promote good designs of virtual agents, robots, machinery, and home appliances according to their intended traits. We categorized these agencies into several groups and discuss what elements lead to these features. The article also describes a method of identifying these features in human behavior. © ISAROB 2011.
PubMed | JST PRESTO
Type: Journal Article | Journal: Langmuir : the ACS journal of surfaces and colloids | Year: 2016
The stereocomplex formation of poly(l,l-lactide) (PLLA) and poly(d,d-lactide) (PDLA) was selected in order to investigate the interaction of the two surfaces including hydrogen bonding and van der Waals interaction. Adhesion force measurement using surface force apparatus (SFA) equipped with an optical microscope was conducted on the PLLA and PDLA spin-coated films. The adhesion forces, Fad, phenomenologically followed the linear relation with the applied normal load, L. For the force Fad between PLLA and PDLA films with low molecular weights (PLLA, Mn = 2800; PDLA, : Mn = 2100), the slope of linear fitting of Fad vs L was significantly larger for the heterointerface (PLLA/PLDA) compared with that for the homointerface (PLLA/PLLA and PDLA/PDLA). However, when polymers with higher molecular weights (PLLA, Mn = 8500; PDLA, Mn = 8300) were measured, the slopes of linear fitting lines were almost the same for hetero- and homointerfaces. This indicated that the mobility of the lower molecular weight PLLA/PDLA films promoted the selective interaction of PLLA and PDLA under the applied normal loads. The adhesion between the outermost PLLA layer and PDLA layer prepared by layer-by-layer (LbL) assembly was also measured. It is interesting that the adhesion force was very weak in this case. This weak adhesion could be explained by the much less mobility of the polymer chain due to the stereocomplex formation within the LbL layers. This study demonstrated that the adhesion force due to the selective interaction of PLLA and PDLA between PLLA/PDLA films could be directly measured, and depended on the mobility of the outermost polymer chains, which reflected the different structures of polymer chains in the organized complex films.