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101.
To understand the relationship between molecular chirality and electrical properties of monolayers, Maxwell displacement current (MDC) behaviors and domain shapes of chiral DPPC monolayers composed of dextro- (d-) and levo- (l-) rotatory molecules at the air-water interface are investigated during monolayer compression using MDC measurement and the Brewster angle microscopy (BAM) system. The experimental results show that for DPPC monolayers of the two pure enantiomers, the π-A isotherms and the MDC behaviors are similar to each other, while the domain patterns of them are mirror shapes of different sizes. This reveals that MDC behaviors due to molecular spontaneous polarization have no relation to chirality but domain shapes closely depend on the molecular chirality. Moreover, the observed domain shapes verify the domain shape theory which was recently developed by Iwamoto et al. [M. Iwamoto, Z.C. Ou-Yang, Phy. Rev. Letts, 93 (2004) 206101]. 相似文献
102.
Reduction of force interference and performance improvement of a consequent-pole bearingless motor 总被引:1,自引:0,他引:1
Junichi Asama Ryo KawataTomoyasu Tamura Takaaki OiwaAkira Chiba 《Precision Engineering》2012,36(1):10-18
A bearingless motor combines the functions of both magnetic suspension and torque generation together in a single motor. A consequent-pole type of bearingless motor has already been proposed. In contrast to conventional bearingless motors, it is free from the trade-off between suspension force and torque. In addition, stable suspension can be achieved without detecting the rotational angle. However, a part of the X-axis current generates undesirable force in the Y-axis. This force interference influences the performances of bearingless motors; thus, the interference should be eliminated. In this paper, the authors propose an optimal winding design of the consequent-pole bearingless motor to minimize the suspension force interference. Here, the suspension forces in the radial direction are numerically calculated using the magneto-motive force distribution of the bearingless motor, and are compared with the analytical results of finite element method. To verify the theory, static and dynamic performance tests were carried out. It was found that the improved winding configuration significantly reduced the suspension force interference by 90% compared with the previous winding configuration. It was also found that the radial shaft vibration and the power consumption were considerably decreased, by approximately 16% and 44%, respectively. 相似文献
103.
Yasutoshi Kasahara Masashi Kato Satoshi Watanabe Makio Iwahashi Rieko Wakamatsu Takashi Suzuki Akinori Kanetani Takaaki Kano Takamitsu Tamura 《Journal of the American Oil Chemists' Society》2012,89(7):1223-1229
Mineral oil is commonly used as an electrical insulating oil in transformers because of its relatively high electrical insulating
ability and fluidity. Considering the depletion of resources and environmental problems, however, fatty acid esters synthesized
from natural plant oils are attracting attention as an environmentally friendly insulating oil. In addition, fatty acid esters
such as methyl octanoate, methyl dodecanoate, 2-ethylhexyl octanoate, and 2-ethylhexyl dodecanoate have high fluidity, and
also show excellent moisture tolerance against dielectric breakdown compared to mineral oil. In the present study, to clarify
the reason for the superior moisture tolerance of fatty acid esters, the status of dissolved water in esters is investigated
with IR spectroscopic measurements and density functional theory (DFT) calculations. It is revealed that water molecules in
fatty acid esters are trapped by the ester moiety of fatty acid esters. As a result, fatty acid esters have a higher moisture
tolerance against dielectric breakdown than mineral oil. 相似文献
104.
Yuuya Fujisawa Takaaki Tsuda Shunsuke Hashimoto Takeshi Sugahara Kazunari Ohgaki 《Chemical engineering science》2012,68(1):660-662
Three-phase equilibrium (pressure–temperature) relation of hydrate+aqueous+fluid phases for the hydrogen (H2)+tetra-n-butyl phosphonium bromide (TBPB)+water ternary system was investigated in a temperature range of 281.90–295.94 K and a pressure range up to 170 MPa. The behavior of the three-phase coexisting curve indicates no structural transition in the present experimental region. The Raman spectra obtained in the H2+TBPB mixed semi-clathrate hydrate crystal reveal that H2 molecule occupies only small cage compartmentally and the TBPB molecule is encaged with a set of other large cages. 相似文献
105.
Tsuruoka T Kawasaki H Nawafune H Akamatsu K 《ACS applied materials & interfaces》2011,3(10):3788-3791
We report a novel approach for synthesizing inorganic nanoparticle/metal-organic frameworks (MOFs) heterostructured nanocomposites by self-assembly of MOFs on nanoparticles. This approach involves the synthesis of Au nanoparticles and preferential growth of [Cu(3)(btc)(2)](n) frameworks consisting of Cu(2+) ions and benzene-1,3,5-tricarboxylate (btc) on nanoparticles. Aggregates consisting of 11-mercaptoundecanoic acid (MUA)-stabilized Au nanoparticles linked by Cu(2+) ions were necessary for preferential self-assembly of [Cu(3)(btc)(2)](n) frameworks on the aggregates, resulting in the formation of Au nanoparticles/[Cu(3)(btc)(2)](n) nanocomposites. The present approach was confirmed to be applicable for other hybrids consisting of Au nanoparticles and tetragonal [Cu(2)(ndc)(2)(dabco)](n) frameworks. 相似文献
106.
Yoshinobu Wakamatsu Hideaki YamadaSatoshi Ninomiya Brian N. JonesToshio Seki Takaaki Aoki Roger WebbJiro Matsuo 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(20):2251-2253
Various imaging techniques using microbeam have been applied in biology. Secondary ion mass spectrometry (SIMS) is one of the prominent tools for biological imaging; SIMS can provide data on molecular distribution in biological samples smaller than 1 μm. However, conventional SIMS has only low sensitivity for molecular ions; therefore there is a need for beams of more sensitive primary ions. Plasma desorption mass spectrometry (PDMS) is a method using high energy fission fragments from excitation of a 252Cf source, and it allows ionization of large molecules (typically up to 20 kDa) due to the dense electronic excitation. Although PDMS is not in use today because of the development of soft ionization methods, ionization induced by high energy ion collision still remains the only method which combines high spatial resolution and sensitive detection of large molecules. In this work, the secondary ion yield of amino acid and phospholipid was measured for 6 MeV Cu4+. The yields were compared to bismuth cluster ions, which achieve relatively high yield. It was confirmed that the swift heavy ion has a couple of hundred times higher yield for large molecules than bismuth cluster ions. 相似文献
107.
Saowaluk Rungchang Sonthaya Numthuam Xiaoli Qiu Yanjie Li Takaaki Satake 《Journal of food engineering》2013
A variety of polyethylene terephthalate (PET) bottles commercially available as soft drink containers from 80 different brands was collected in Japan and subsequently examined to determine the amount of Sb in both the PET plastic and drink. The concentration of Sb in the plastic material ranged from 0.1 to 216.5 mg/kg, while this value ranged from 0.3 to 1.6 μg/L in bottled solutions. The diffusion coefficients of Sb in PET samples were determined at 25, 40, 55, and 70 °C. The migrated-Sb in all simulated food solutions (e.g., ultra pure water, 4% acetic acid, and 50% ethanol) increased with storage time and temperature. The temperature-dependent diffusion coefficients were derived from the Arrhenius equation. The predicted model for Sb migration suggested that storage conditions of all PET drink products should be below 70 °C for a maximum of 72 d to avoid Sb levels above the recommended value of 5 μg/L, which is based on the European standards. 相似文献
108.
Kenichiro Sato Masahiro Kameda Takao Yasuhara Takashi Agari Tanefumi Baba Feifei Wang Aiko Shinko Takaaki Wakamori Atsuhiko Toyoshima Hayato Takeuchi Tatsuya Sasaki Susumu Sasada Akihiko Kondo Cesario V. Borlongan Mitsunori Matsumae Isao Date 《International journal of molecular sciences》2013,14(11):21513-21524
The number of diabetes mellitus (DM) patients is increasing, and stroke is deeply associated with DM. Recently, neuroprotective effects of glucagon-like peptide-1 (GLP-1) are reported. In this study, we explored whether liraglutide, a GLP-1 analogue exerts therapeutic effects on a rat stroke model. Wistar rats received occlusion of the middle cerebral artery for 90 min. At one hour after reperfusion, liraglutide or saline was administered intraperitoneally. Modified Bederson’s test was performed at 1 and 24 h and, subsequently, rats were euthanized for histological investigation. Peripheral blood was obtained for measurement of blood glucose level and evaluation of oxidative stress. Brain tissues were collected to evaluate the level of vascular endothelial growth factor (VEGF). The behavioral scores of liraglutide-treated rats were significantly better than those of control rats. Infarct volumes of liraglutide-treated rats at were reduced, compared with those of control rats. The level of derivatives of reactive oxygen metabolite was lower in liraglutide-treated rats. VEGF level of liraglutide-treated rats in the cortex, but not in the striatum significantly increased, compared to that of control rats. In conclusion, this is the first study to demonstrate neuroprotective effects of liraglutide on cerebral ischemia through anti-oxidative effects and VEGF upregulation. 相似文献
109.
Toshio Suzuki Yoshihiro Funahashi Toshiaki Yamaguchi Yoshinobu Fujishiro Masanobu Awano 《Journal of power sources》2008
Tubular SOFCs have shown many desirable characteristics such as high thermal stability during rapid heat cycling and large electrode area per unit volume, which can accelerate to realize SOFC systems applicable to portable devices and auxiliary power units for automobile. So far, we have developed anode-supported tubular SOFCs with 0.8–2 mm diameter using Gd-doped CeO2 (GDC) electrolyte, NiO-GDC anode and (La, Sr)(Co, Fe)O3 (LSCF)-GDC cathode. In this study, a newly developed cube-type SOFC stack which consists of three SOFC bundles was designed and examined. The bundle consists of three 2 mm diameter tubular SOFCs and a rectangular shaped cathode support where these tubular cells are arranged in parallel. The performance of the stack whose volume is less than 1 cm3 was shown to be 2.8 V OCV and over 1 W at 1.6 V under 500 °C. Cathode loss factor due to current collection from cathode matrix was also estimated using a proposed model. 相似文献
110.
With bolometer application in mind, we prepared VO2 films on TiO2 (001) substrates by an excimer-laser-assisted metal organic deposition process at 300 °C or less. A metal-to-insulator transition of VO2 is expected to induce high temperature coefficient of electrical resistance (TCR) useful for high-performance infrared sensors, but the practical use of crystalline VO2 films has been prevented due to the accompanied wide hysteresis. In this study, by forming the epitaxial phase only near the substrate interface, the transition of the film was successfully broadened and the hysteresis disappeared. The maximum TCR of the film was more than -10%/°C near room temperature, and the temperature range in which TCR was higher than -4%/°C was very wide (280-320 K). 相似文献