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141.
Direct imaging of single-walled carbon nanotubes (SWNTs) suspended on pillar-patterned Si or SiO2 substrates is investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The suspended nanotubes are successfully observed by direct TEM imaging and it is seen that they have either individual or bundles of SWNTs. Low energy (< or =2 keV) SEM produces high contrast images of suspended SWNTs. On the contrary, when SWNTs contact a SiO2 substrate, they are imaged using electron-beam induced current. The image brightness depends on the length of SWNTs. 相似文献
142.
143.
A mathematical model for grinding wheel redress life is identified by the polynomial theory of complex systems. Wheel speed, feed, grain size and grade are chosen as the independent variables from among the factors considered to have an effect on wheel wear through the identification of the model. The model obtained enables the redress life to be predicted for all combinations of grinding wheel, work material and grinding conditions, and serves as an aid in the optimization of the grinding process. 相似文献
144.
The carbon-13 n.m.r. spin-lattice relaxation times, nuclear Overhauser enhancement factor (NOE), and line widths have been measured for a syndiotactic poly(α-methylstyrene) in solutions in toluene-d8 and o-dichlorobenzene-d4 as a function of temperature from 40° to 163δC. The single correlation time model of relaxation is inadequate to explain the data of spin-lattice relaxation time and NOE. But, within experimental error, these relaxation data in two solvents over a full temperature range can be interpreted in terms of either the Cole-Cole or the log-χ2 distributions of correlation times, or a conformational jump model proposed by Monnerie et al. The internal rotation of the methyl group is relatively rapid, while that of the phenyl ring is slow and practically overshadowed by the backbone segmental reorientation over the temperature range examined. The solvent dependence of relaxation data was discussed. 相似文献
145.
The thermal dilatation in (NH3 ·CH3) SnCl6, (NH3 · C2H5) SnCl6 and [N(CH3)] SnCl6 was measured, and as the results it has turned out that (NH3 6·C2H5) SnCl6 and [N(CH3)4]2 SnCl6 undergo the first order transitions at 128 K and 158 K, respectively. The low temperature phases of (NH · C2H5) SnCl6 and [N(CH3)4]2 SnC16 are found to be monoclinic and tetragonal, respectively, No phase transition was observed in (NH3 ·CH3)2 SnCl6 down to 77 K. 相似文献
146.
The reaction of isobutene (IB) with its dimers (IB2) catalyzed by CF3SO3H yielded isobutene trimers (IB3) in high yield in nonpolar solvents at 0°C. The initial feed of isobutene, in the presence of equimolar IB2 or more, was selectively converted into IB3 without loss or accumulation of IB2. After complete consumption of the isobutene, however, the remaining IB2 rapidly dimerized to isobutene tetramers (IB4). 13C-NMR analysis of the products showed that the IB3 was formed via addition of the t-butyl cation (protonated isobutene to 2,4,4-trimethyl-1-pentene (an IB2 isomer); the trimer fraction was free from isomers arising from addition of the t-butyl cation to 2,4,4-trimethyl-2-pentene (another IB2 isomer) or addition of the IB2 cation to isobutene. The IB3 thus obtained was further oligomerized with CF3SO3H catalyst in nonpolar media in the range of 0 to ?25°C to give a mixture of IB5, IB6, and IB7 in high yield. With EtAlCl2 as catalyst, reaction of isobutene with IB2 and oligomerization of IB3 both resulted in products with a broad molecular weight distribution containing higher oligomers and complex hydrocarbons formed via cracking of the intermediate carbocations. 相似文献
147.
Yumiko Kaji Ryoji Mitsuhashi Xuesong Lee Hideki Okamoto Takashi Kambe Naoshi Ikeda Akihiko Fujiwara Minoru Yamaji Kenji Omote Yoshihiro Kubozono 《Organic Electronics》2009,10(3):432-436
C60 and picene thin film field-effect transistors (FETs) in bottom contact structure have been fabricated with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) electrodes for a realization of mechanical flexible organic FETs. The C60 thin film FETs showed n-channel enhancement-type characteristics with the field-effect mobility μ value of 0.41 cm2 V?1 s?1, while the picene thin film FET showed p-channel enhancement-type characteristics with the μ of 0.61 cm2 V?1 s?1. The μ values recorded for C60 and picene thin film FETs are comparable to those for C60 and picene thin film FETs with Au electrodes. 相似文献
148.
Satria Zulkarnaen Bisri Taishi Takenobu Yohei Yomogida Hidekazu Shimotani Takeshi Yamao Shu Hotta Yoshihiro Iwasa 《Advanced functional materials》2009,19(11):1728-1735
A high‐performance ambipolar light‐emitting transistor (LET) that has high hole and electron mobilities and excellent luminescence characteristics is described. By using this device, a conspicuous light‐confined edge emission and current‐density‐dependent spectral evolution are observed. These findings will result in broader utilization of device potential and they provide a promising route for realizing electrically driven organic lasers. 相似文献
149.
Kenji Ozeki Yoshihiro TakagiShinobu Oda Shinichi Ohashi 《Journal of Bioscience and Bioengineering》2010,109(3):224-226
Xylanase production by a XynF1 (33 kDa)-transformant of Aspergillus oryzae RIB40 was compared between submerged cultivation (SmC) and liquid-surface immobilization (LSI) systems. While the accumulation of xylanase in the SmC decreased by prolonged incubation, LSI system enabled the continuation of xylanase production to afford 4.5-fold xylanase production compared with the SmC system. 相似文献
150.
Makoto Sakuragi Saki Tsuzuki Hirokazu Hasuda Akira Wada Kenji Matoba Izumi Kubo Yoshihiro Ito 《应用聚合物科学杂志》2009,112(1):315-319
A novel photoreactive polymer with histidine polar groups was synthesized through the copolymerization of two types of methacrylic acid, one carrying histidine groups and the other carrying azidoaniline groups. The polymer was photoimmobilized on polyester disks for surface modification. The effect of the surface modification on the hydrophilic and biofouling properties was investigated. Static contact angle measurements showed that the polymeric surface was modified to be comparatively hydrophilic in the polymer‐immobilized region. Micropattern immobilization was carried out with a photolithographic method. Atomic force microscopy measurements showed that the polymer was formed on the disks in response to ultraviolet irradiation. Protein adsorption was reduced on the polymer‐immobilized regions, and in those regions, spreading and adhesion of mammalian cells were reduced in comparison with that in nonimmobilized regions. In conclusion, a novel histidine‐containing polymer was photoreactively immobilized on a conventional polymer surface, and it had reduced interaction with proteins and cells. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献