Showing papers by "Hiroshi Yokoyama published in 2005"
TL;DR: Reversible luminescence intensity variations and spectral shifts of QD clusters show the potential for developing sensors based on QD nanoscale assemblies and reversible thermal trapping of electrons at inter-QD interfaces and dipole-dipole interactions in clusters.
Abstract: The formation of narrow size dispersed and nanometer size aggregates (clusters) of cadmium selenide (CdSe) quantum dots (QDs) and their temperature-sensitive photoluminescence (PL) spectral properties close to room temperature (298 K) are discussed. CdSe QDs formed stable clusters with an average diameter of ∼27 nm in the absence of coordinating solvents. Using transmission electron microscopy (TEM) imaging, we identified the association of individual QDs with 2−5 nm diameters into clusters of uniform size. A suspension of these clusters in different solvents exhibited reversible PL intensity changes and PL spectral shifts which were correlated with temperature. Although the PL intensity of CdSe QDs encapsulated in host matrixes and the solid state showed a response to temperature under cryogenic conditions, the current work identified for the first time QD clusters showing temperature-sensitive PL intensity variations and spectral shifts at moderate temperatures above room temperature. Temperature-sensit...
180 citations
01 Dec 2005
TL;DR: In this paper, an ink-jet system was developed for direct fabrication of ultra-fine redistribution wires for a build-up board and/or package, which can be used for both nanotechnology research and applications such as micro electronics, etc.
Abstract: We have developed an ink-jet system which allows arrangements of dots with a submicron minimum size. Using an ultra-fine silver paste, we achieved the direct print of metallic wires of only a few micrometers in width without any pre-patterning treatment of the substrate, hydrophobic/hydrophilic patterning, bank patterning etc. We also propose an application, such as direct printing of ultra-fine redistribution wiring for a build-up board and/or package. Since all of these processes can be carried out at atmospheric pressure on the desktop without special treatment of the substrate. The direct fabrication process using ink-jet printing can be expected to be a powerful tool for both nanotechnology research and applications such as micro electronics, etc.
117 citations
TL;DR: Ferromagnetic-film-coated carbon nanotube (CNT) probes were employed in a magnetic force microscope (MFM) observation as mentioned in this paper, and they succeeded in making a uniform ferromagnetic film on the CNT probes by improving the coating process.
Abstract: Ferromagnetic-film-coated carbon nanotube (CNT) probes were employed in a magnetic force microscope (MFM) observation. We succeeded in making a uniform ferromagnetic film on the CNT probes by improving the coating process and selecting materials. The performance of the CoFe-coated CNT probe was evaluated in ultra-high-density perpendicular magnetic storage media with densities from 600 to 1100?k flux changes per inch (FCI). The magnetic domain structure of the magnetic storage media was clearly observed up to 1100?kFCI. The ultimate lateral resolution of the newly developed MFM probes is down to about 10?nm, which exceeds the bit length of a magnetic recording with a density of Tbit?inch?2.
64 citations
TL;DR: The subsecond PL intensity fluctuations of single CdSe QDs and short-lived "on" and "off" states to a high-density distribution of homogeneous surface trap states are attributed.
Abstract: Photoluminescence (PL) intermittency characteristics are examined for single quantum dots (QDs) in a CdSe QD sample synthesized at a slow rate at 75 degrees C. Although the PL quantum efficiency was relatively low ( approximately 0.25), we noticed that the PL intensity of single CdSe QDs fluctuated on a subsecond time scale with short-lived "on" and "off" states. The subsecond PL intensity fluctuations of CdSe QDs are different from "on" and "off" PL blinking generally observed for QDs fluctuating on a millisecond to minute time scale. We characterized single QDs by identifying polarized excitations, topographic imaging using atomic force microscopy (AFM), and transmission electron microscopy (TEM). From analysis of the PL intensity trajectories from >100 single CdSe QDs, the average intermittency time was 213 ms. From the PL quantum efficiency, slow growth of QDs, intensity trajectory analyses, and previous reports relating surface trap states and PL properties of QDs, we attribute the subsecond PL intensity fluctuations of single CdSe QDs and short-lived "on" and "off" states to a high-density distribution of homogeneous surface trap states.
53 citations
TL;DR: A liquid crystal smectic blue phase (SmBPiso), formed from a two-component mixture containing a chiral monomer and a ‘twin’ containing two repeat units of the first molecule connected by a linear hydrocarbon spacer, is reported.
Abstract: When liquid crystal molecules are chiral, the twisted structure competes with spatially uniform liquid crystalline orders, resulting in a variety of modulated liquid crystal phases, such as the cholesteric blue phase1, twist grain boundary2,3,4 and smectic blue phases5. Here we report a liquid crystal smectic blue phase (SmBPiso), formed from a two-component mixture containing a chiral monomer and a ‘twin’ containing two repeat units of the first molecule connected by a linear hydrocarbon spacer. The phase exhibits the simultaneous presence of finite local-order parameters of helices and smectic layers, without any discontinuity on a mesoscopic length scale. The anomalous softening of elasticity due to a strong reduction in entropy caused by mixing the monomer and the twin permits the seamless coexistence of these two competing liquid crystal orders. The new phase spontaneously exhibits an optically isotropic but uniformly iridescent colour and automatically acquires spherical symmetry, so that the associated photonic band gap6,7,8,9 maintains the same symmetry despite the local liquid crystalline order. We expect a range of unusual optical transmission properties based on this three-dimensional isotropic structure, and complete tunability due to the intrinsic softness and responsiveness of the liquid crystalline order against external fields.
53 citations
TL;DR: Morphological and molecular analyses of the myxozoan from splendid alfonso identified it as Kudoa megacapsula n.
Abstract: Postmortem myoliquefaction associated with multivalvulid myxozoans was found in fillets of red barracuda (Sphyraena pinguis) and splendid alfonso (Beryx splendens), which were imported to Japan from China and South Africa, respectively. Morphological examinations of the myxozoans from the somatic muscle of red barracuda revealed that spores (30.3–44.7 μm in maximum thickness) had 4 distinct winglike valves, in which 1 extremely large (12.7 × 5.8 μm), 2 small, and 1 vestigial polar capsule were present. The small subunit ribosomal DNA sequence analysis showed that the myxozoan cluster within a clade was composed of Kudoa thyrsites, Kudoa minithyrsites, and Kudoa lateolabracis, all having stellate spores with 1 polar capsule larger than the other 3. On the basis of these characteristics, we describe this parasite as Kudoa megacapsula n. sp. Morphological and molecular analyses of the myxozoan from splendid alfonso identified it as K. thyrsites, which has been described from many marine fishes. To our knowle...
50 citations
TL;DR: In this article, a homologous series of novel λ-shaped mesogenic compounds in which three mesogenic groups are connected to 3, 4-dihydroxybenzoic acid has been prepared and their physical properties investigated by means of optical microscopy, differential scanning calorimetry and X-ray diffraction measurements.
Abstract: A homologous series of novel λ-shaped mesogenic compounds in which three mesogenic groups are connected to 3, 4-dihydroxybenzoic acid has been prepared and their physical properties investigated by means of optical microscopy, differential scanning calorimetry and X-ray diffraction measurements. The λ-shaped compounds studied showed unusual smectic phases. 4-Cyanobiphenyl-4′-yl 3,4-bis{6-[4-(5-octylpyrimidin-2-yl)phenyloxy]hexyloxy}benzoate was found to realize an incommensurate SmA (SmAinc) phase. A “uniform planarly” aligned sample of 2-(4-octylphenyl)pyrimidin-5-yl 3,4-bis{6-[4-(5-octylpyrimidin-2-yl)phenyloxy]hexyloxy} benzoate showed a Schlieren-like texture in the smectic phase. We discuss structural effects of the λ-shaped compounds on molecular organization in liquid-crystalline phases.
49 citations
TL;DR: Henneguya pagri n.
Abstract: Henneguya pagri n. sp. (Myxozoa: Myxosporea) is described from netpen-cultured red sea bream, Pagrus major, in Japan. Affected fish displayed anaemic gills, an enlarged bulbus arteriosus and internal haemorrhaging in the pericardial cavity. Disease outbreaks occurred during the summer and the prevalence of infection reached 75% in August. Plasmodia of H. pagri developed in the bulbus arteriosus of red sea bream, in which degenerative cardiomyopathy was observed. Following maturation of the parasite, the influx of spores into the gills caused congestion of the gill capillaries, resulting in proliferative branchitis. Spores (10.5 x 7.5 microm) were ovoid with two caudal appendages (29.6 microm in average length), with a whip-like extension from the end. Partial small subunit ribosomal RNA gene sequences of H. pagri are closely related to those of H. lateolabracis infecting the bulbus arteriosus of Chinese sea bass, Lateolabrax sp.
43 citations
TL;DR: The interaction between two spherical particles carrying the same topological charges +1 mediated by the elastic distortion of a nematic liquid crystal is investigated with the aid of the Landau-de Gennes continuum theory and it is found that the interaction is attractive and its potential energy depends linearly on the interparticle distance D.
Abstract: We investigate numerically with the aid of the Landau-de Gennes continuum theory the interaction between two spherical particles carrying the same topological charges +1 mediated by the elastic distortion of a nematic liquid crystal. We consider the case where an escaped nontopological ring disclination is situated between the particles; the director is continuous everywhere and no counterdefects are present. We find that the interaction is attractive and its potential energy depends linearly on the interparticle distance D. This behavior yields the D-independent interaction force, which was observed experimentally by Poulin, Cabuil, and Weitz [Phys. Rev. Lett. 79, 4862 (1997)] in the presence of narrow strings of birefringent regions ("bubble-gum" configuration) between the particles.
34 citations
TL;DR: In this article, the optimal sputtering conditions for obtaining a uniform ferromagnetic film on a carbon nanotube (CNT) probe were investigated using a scanning electron microscope and an atomic force microscope.
Abstract: CoFe-coated carbon nanotube (CNT) probes have been successfully fabricated by a radio-frequency sputtering method. The sputtering conditions for obtaining a uniform ferromagnetic film on the CNT probe were investigated. The optimal sputtering conditions were determined from the observations using a scanning electron microscope and an atomic force microscope. CNT magnetic force microscope (MFM) probes prepared under optimized conditions provided us clear images with an ultimate lateral resolution of approximately 10 nm.
31 citations
TL;DR: Parasitological and histopathological examinations revealed that the developmental stages of Enteromyxum Ieei parasitized the intestinal epithelium of diseased fish, indicating that the myxosporean emaciation disease of Japanese flounder is caused by E. leei.
Abstract: The myxosporean emaciation disease has been recently found in Japanese flounder Paralichthys olivaceus cultured in land-based tanks in Miyazaki Prefecture, Japan. Affected fish showed external signs of distended abdomen, rectal prolapse, sunken eyes and a typical bony ridge on the skull. Parasitological and histopathological examinations revealed that the developmental stages of Enteromyxum Ieei parasitized the intestinal epithelium of diseased fish. No other enteric myxozoans were observed in the affected fish. A molecular analysis of SSU rDNA confirmed that the causative myxozoan was identified as E. leei. Experimental transmission of E. leei was achieved to naive Japanese flounder and tiger puffer Takifugu rubripes by feeding with gut tissues taken from infected Japanese flounder. The present study indicates that the myxosporean emaciation disease of Japanese flounder is caused by E. leei.
TL;DR: These results emphasize the importance of structural features of sugar-chain ligands on the membrane surface of liposomal nanoparticles in active targeting DDS nanoparticles.
TL;DR: A polymerase chain reaction (PCR) -based method was developed to detect enteric myxozoans which cause the emaciation disease of cultured tiger puffer Takifugu rubripes and successfully detected parasite DNA from the intestinal mucosa of killed fish and gut contents collected from live fish using a swab inserted into the anus.
Abstract: A polymerase chain reaction (PCR) -based method was developed to detect enteric myxozoans which cause the emaciation disease of cultured tiger puffer Takifugu rubripes. Three primer sets were designed based on the sequences of small subunit ribosomal DNA of Enteromyxum leei, Enteromyxum fugu and Leptotheca fugu. All of the primer sets specifically amplified the target DNA of each species. The PCR successfully detected parasite DNA not only from the intestinal mucosa of killed fish but also from gut contents collected from live fish using a swab inserted into the anus. These PCR analyses were more sensitive to detection of parasites than microscopic observation on the intestinal imprints. The present PCR method is useful for rapid diagnosis of the myxosporean emaciation disease.
TL;DR: In this paper, the authors studied numerically the interaction between particles in a nematic liquid crystal mediated by its elastic distortions with the aid of the Landau-de Gennes continuum theory.
Abstract: We study numerically the interaction between particles in a nematic liquid crystal mediated by its elastic distortions with the aid of the Landau-de Gennes continuum theory. We consider the cases where two particles impose rigid normal anchoring on their surfaces and are accompanied by a hyperbolic hedgehog defect. As a function of the distance between the centers of the particles D, we evaluate the force f acting on the particles by integrating the stress tensor. The result is well described by a power law f ∝ D −x . When the “dipoles”, composed of a particle and a hyperbolic hedgehog, are in parallel directions, the interaction is attractive and the exponent is x ≃ 4, consistent with the experimental observations together with the theoretical expectation of the dipole-dipole interaction. For antiparallel dipoles, repulsive interaction is observed and x ≃ 3.6, slightly stronger than the dipole-dipole interaction.
TL;DR: In this article, the effect of a hydrodynamic flow on the orientational configuration of a nematic liquid crystal around a spherical particle imposing rigid normal anchoring was studied, and it was shown that strong elastic deformation by the flow is expected.
Abstract: We study the effect of a hydrodynamic flow on the orientational configuration of a nematic liquid crystal around a spherical particle imposing rigid normal anchoring. We discuss the cases of large Ericksen numbers (characterizing the ratio of viscous force to the elastic force), where strong elastic deformation by the flow is expected. We assume the Stokes flow profile and deal with a simplified dynamic equation of the orientational order parameter of a second-rank tensor Q αβ. We consider the cases where a particle accompanying a hyperbolic hedgehog or a Saturn ring is subjected to a flow along the axis of rotational symmetry. In both cases the orientation profiles exhibit considerable deformation by a flow.
TL;DR: In this article, a variety of superstructures are generated in the chiral smectic phases, including ferrielectric and antiferroelectric phases, a twist grain boundary phase and the variants, such as smectric blue and Smectic Q phases, and mysterious isotropic phases exhibiting an anomalous electric-field induced phase transition.
Abstract: Molecular design producing a strong chiral effect has been proposed and dichiral twin and monomeric materials have been prepared systematically based on this concept. A variety of superstructures are generated in the chiral smectic phases, including ferrielectric and antiferroelectric phases, a twist grain boundary phase and the variants, such as smectic blue and smectic Q phases, and mysterious isotropic phases exhibiting an anomalous electric-field induced phase transition.
TL;DR: The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above, and the frictionDrag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer.
Abstract: We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter ${Q}_{\ensuremath{\alpha}\ensuremath{\beta}}$ is employed. We solve the hydrodynamic equations for ${Q}_{\ensuremath{\alpha}\ensuremath{\beta}}$ and the fluid velocity $\ensuremath{\upsilon}$ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter.
TL;DR: A general approach to the description of the long-ranged interaction between nanoparticles (1-10 nm) of ordinary shape in the paranematic phase, i.e., nematic liquid crystal in the isotropic phase, where in general case interaction potential is attractive of Yukawa form with derivatives but it can be anisotropic despite the isotropy of the paran ematic phase.
Abstract: We propose a general approach to the description of the long-ranged interaction between nanoparticles s 1‐1 0 nmd of ordinary shape in the paranematic phase, i.e., nematic liquid crystal in the isotropic phase. In general case interaction potential is attractive of Yukawa form with derivatives. But it can be anisotropic despite the isotropy of the paranematic phase. The origin of such anisotropy is the shape of nanoparticles. Particular potentials for spherical and cylindrical particles are considered. For the case of nanocylinders anisotropic part of the interaction potential can lead to the orientational ordering of them in the isotropic phase of nematic liquid crystals.
TL;DR: In this paper, both peripheral ends of some straight-shaped mesogenic compounds, possessing a biphenyl or azobenzene as a central rigid core, have been systematically modified, and the effect on the liquid-crystalline properties investigated.
Abstract: Both peripheral ends of some straight-shaped mesogenic compounds, possessing a biphenyl or azobenzene as a central rigid core, have been systematically modified, and the effect on the liquid-crystalline properties investigated. A fluorinated moiety introduced into the peripheral alkyl chains stabilized the smectic phase, whereas that into the terminally positioned phenyl rings resulted in the appearance of the nematic phase. Introduction of phenyl rings into the middle of the flexible chains produced a well-defined smectic layered structure. Further introduction of another phenyl ring at each terminal end was found to show a significant effect on the determination of the clinicity.
TL;DR: In this paper, the electrooptical characteristics, microscopic textures, the tilt angle and the chevron angle of the polymer-stabilized ferroelectric liquid crystals (PSFLCs) photocured in the SmA phase were measured, and then the molecular alignment structure was discussed from these results.
Abstract: In order to realize monostability in surface-stabilized ferroelectric liquid crystals, polymer stabilization techniques have been proposed, and the polymer-stabilized ferroelectric liquid crystals (PSFLCs), which is fabricated by UV photocure of doped photocurable mesogenic monomers at a temperature where the FLC medium is in the SmA phase, has been reported to show V-shaped electrooptical characteristics. However, the reason why the monostable V-shaped switching can be realized has not been clear yet. In this research, the electrooptical characteristics, the microscopic textures, the tilt angle and the chevron angle of the PSFLCs photocured in the SmA phase were measured, and then the molecular alignment structure was discussed from these results.
TL;DR: In this paper, the spacer length of a liquid-crystalline molecule I-n has been investigated to investigate the effect of spacer lengths on the phase transition behavior.
Abstract: We reported that a novel λ-shaped liquid-crystalline molecule I-6 in which a cyanobiphenyl and two phenylpyrimidine groups are connected to 3, 4-dihydroxybenzoic acid exhibits an incommensurate SmA phase. In the present study, we have prepared the homologous series of the λ-shaped molecules I-n ( n = 4 , 5 , 7 , 8 , 9 , 12 ) and investigated effect of the spacer length on the phase transition behaviour. Compounds I-4 , I-8 and I-12 with an even member of atoms in spacer showed the phase sequences of N-SmA-Cr or SmA-Cr. On the other hand, the odd members I-7 and I-9 showed the phase sequence of N-SmA-SmCanti-Cr.
TL;DR: The phase behavior of an optically isotropic, thermotropic cubic mesogen 4-(ethylpentoxy)-anilinebenzylidenen-4′-carboxylic acid was investigated under pressures up to 300 MPa using a high-pressure differential thermal analyzer, a wide-angle X-ray diffractometer (WAXD) and a polarizing optical microscope (POM) equipped with a high pressure optical cell.
TL;DR: The phase transition behavior of three homologous discotic mesogens, the hexa−n−alkoxyanthraquinones HOAQ(n), n indicating the number of carbon atoms in the alkoxy group, was investigated under hydrostatic pressures up to 500 MPa using a high pressure differential thermal analyser as discussed by the authors.
Abstract: The phase transition behaviour of three homologous discotic mesogens, the hexa‐n‐alkoxyanthraquinones HOAQ(n), n indicating the number of carbon atoms in the alkoxy group, was investigated under hydrostatic pressures up to 500 MPa using a high pressure differential thermal analyser. The T vs. P phase diagrams of HOAQ(6), HOAQ(8) and HOAQ(9) were constructed for solution‐ (Cr0) and melt‐crystallized (Cr1) samples of the compounds. HOAQ(6) shows the reversible Cr0–rectangular columnar phase (Colr)–hexagonal columnar phase (Colh)–isotropic liquid (I) phase sequence at atmospheric pressure. The stable Colr phase of HOAQ(6) has a decreased temperature range with increasing pressure and then the Colr phase disappears under pressures above about 350 MPa; instead the Cr0–Colh–I phase sequence is exhibited. For HOAQ(8), the solution‐grown sample exhibits the stable Cr0–Colh–I phase sequence at atmospheric pressure. Applying pressure to the solution‐grown sample induces the formation of the stable Colr phase in the...
TL;DR: In this article, the phase transition behavior of two achiral bent core banana-shaped molecules, 3- and 3-(3′-chloro-)(4′- n -octyloxybenzoyloxyphenyliminomethyl)phenyl-4″-n -decoyed biphenylcarboxylate (I and II ), showing the B 1 and B 2 banana phases, respectively, was investigated under hydrostatic pressures up to 300MPa using a high-pressure differential thermal analyzer.
Patent•
01 Sep 2005
TL;DR: In this paper, an anchor bolt attached with an expansion member smaller than an inlet inner diameter of a bore hole on the tip and larger than an outer diameter of an anchor Bolt when positioned in the bore hole expansion hole, is inserted into the Bore Hole of expanding a Bore Hole bottom part of hardened concrete.
Abstract: PROBLEM TO BE SOLVED: To improve extraction yield strength when shearing force acts in the 45-degree direction from a part on the concrete surface side of an expansion member positioned in a bore hole expansion hole by the expansion member of an anchor bolt tip part. SOLUTION: An anchor bolt attached with the expansion member smaller than an inlet inner diameter of a bore hole on the tip and larger than an outer diameter of an anchor bolt when positioned in the bore hole expansion hole, is inserted into the bore hole of expanding a bore hole bottom part of hardened concrete. The expansion member is positioned in the expansion hole of the bore hole. An organic injection material or an inorganic injection material is filled in a bore hole void. COPYRIGHT: (C)2007,JPO&INPIT
TL;DR: Temperature manipulation is partially effective as a preventive method of K. takedai infection in salmonids under field and experimental conditions.
Abstract: Effects of water temperature on infection of the microsporidian Kabatana takedai were investigated in salmonids under field and experimental conditions. “Cysts” of K. takedai appeared in the heart and the skeletal muscle of wild juvenile masu salmon Oncorhynchus masou from the Chitose River, Hokkaido, during summer in 2003 and 2004, when the river water temperature exceeded 15°C. Following the exposure of naive juvenile sockeye salmon Oncorhynchus nerka to river water (18-19°C) for 3 days, the fish were transferred to separate tanks where the temperatures were set to 11, 13, 15 and 17°C. Prevalence of infection reached more than 70% in the 13, 15 and 17°C groups, but in the 11°C group, it remained less than 30%. However, shifting a part of the 11°C group to 18°C increased the prevalence to 71 % by 23 days after the elevation of the temperature. When juveniles were exposed to 11°C river water and subsequently kept at 9°C for 42 days, no development of K. takedai occurred even after the temperature was elevated to 15°C. These results indicate that temperature manipulation is partially effective as a preventive method of K. takedai infection.
TL;DR: In this paper, the roles of chemical structure of compositional segments in relation to liquid crystalline phase formation were investigated in polycatenar materials composed of a four-aromatic-ring core, with either a bulky or end-branched perfluorinated moiety attached at one end through a methylene spacer group.
Abstract: Polycatenar materials composed of a four‐aromatic‐ring core, with either a bulky or end‐branched perfluorinated moiety attached at one end through a methylene spacer group, and three peripheral alkoxy chains of varying length (the carbon number n = 4, 6, 8, 10, 12, 14, 16) on the other end‐ring, were synthesized to investigate the roles of the chemical structure of the compositional segments in relation to liquid crystalline phase formation. It was found that a homologous series of polycatenar materials exhibited a variety of liquid crystalline phases strongly dependent on the length of the peripheral alkyl chains. Moreover it was shown that changes in the spacer group and in the structure of the perfluorinated segment had a significant influence on mesophase formation.
Patent•
19 Oct 2005
TL;DR: In this paper, the authors showed that focused laser light could heat up only the selected region in the cell including a light-absorbing medium, and the switched region was stable without the disturbance from the exterior.
Abstract: Orientational bistability of the nematic liquid crystal occurs on the frustrated surface alignment of checkerboard. Macroscopic orientational switching takes place between two states by an appropriate in-plane electric field. The threshold electric fields decreased in both switching directions as temperature increased. The focused laser light could heat up only the selected region in the cell including a light-absorbing medium. Irradiating the laser concurrently with an appropriate electric field, we switched the selected regions in the alignment pattern. The switched region was stable without the disturbance from the exterior. Extending this process, we realized extremely fine bistable devices. Here we mention some issues like the switching domains and the relation between the threshold electric filed and temperature.
TL;DR: In this article, the authors used sum-frequency vibrational spectroscopy (SFVS) to probe the chirality of a polymer thin film and found that the chiral nonlinear susceptibilities for SFVS for the two enantiomers have opposite signs.
Abstract: Sum-frequency vibrational spectroscopy (SFVS) has been used to probe the chirality of a polymer thin film. The polymer used has a π─electron conjugated structure in the main chain, and a chiral center in the side chains that is close to the main chain, giving rise to the helically twisted main chain. The vibrational modes probed are stretches associated with the main chain. As expected for chiral responses, we find that the chiral SFVS spectra are identical for the two enantiomers, and the signal vanishes for the racemic polymer. We also confirm experimentally that the chiral nonlinear susceptibilities for SFVS for the two enantiomers have opposite signs.