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排序方式: 共有279条查询结果,搜索用时 15 毫秒
91.
H. Takeda C. Fujioka R. Aoyagi S. Okamura T. Shiosaki 《Applied Physics A: Materials Science & Processing》2005,81(1):131-135
The piezoelectric properties of strontium bismuth tantalate SrBi2Ta2O9 (SBT) ceramics were enhanced by introducing off-stoichiometry into the starting materials. Sr-deficient and Bi-excess SBT, Sr0.8Bi2.2Ta2O9 (S0.8B2.2T), ceramic samples were prepared by a conventional ceramic technique. The optimum poling conditions (temperature Tp, time tp, and electric field Ep) were investigated for the piezoelectric measurement. All the obtained independent electromechanical coupling factors of the S0.8B2.2T dense ceramics were as follows: kp=10.6, k31=6.8, k33=14.0, k15=7.8, and kt=16.2%. The physical constants of the S0.8B2.2T ceramics were also determined. The piezoelectric constants were d33=13.0, d31=6.0, and d15=10.2 pC/N. PACS 77.84.Dy; 61.66.Fn; 77.65.-j 相似文献
92.
93.
Numata M Aoyagi Y Matsuo M Ishikawa K Hanari N Otsuka S Tsuda Y Yarita T 《Analytical and bioanalytical chemistry》2008,391(6):1985-1995
Four mineral oil certified reference materials (CRMs), NMIJ CRM 7902-a, CRM 7903-a, CRM 7904-a, and CRM 7905-a, have been
issued by the National Metrology Institute of Japan, which is part of the National Institute of Advanced Industrial Science
and Technology (NMIJ/AIST), for the determination of polychlorinated biphenyls (PCBs). The raw materials for the CRMs were
an insulation oil (CRM 7902-a and CRM 7903-a) and a fuel oil (CRM7904-a and CRM 7905-a). A solution of PCB3, PCB8, and technical
PCB products, comprising four types of Kaneclor, was added to the oil matrices. The total PCB concentrations in the PCB-fortified
oils (CRM 7902-a and CRM 7904-a) are approximately 6 mg kg−1. In addition, the mineral oils which were not fortified with PCBs were also distributed as CRMs (CRM 7903-a and CRM 7905-a).
Characterization of these CRMs was conducted by the NMIJ/AIST, where the mineral oils and the PCB solution were analyzed using
multiple analytical methods such as dimethylsulfoxide extraction, normal-phase liquid chromatography, gel permeation chromatography,
reversed-phase liquid chromatography, and chromatography using sulfoxide-bonded silica; and/or various capillary columns for
gas chromatography, and two ionization modes for mass spectrometry. The target compounds in the mineral oils and those in
the PCB solution were determined by one of the primary methods of measurement, isotope dilution–mass spectrometry (ID-MS).
Certified values have been provided for 11 PCB congeners (PCB3, 8, 28, 52, 101, 118, 138, 153, 180, 194, and 206) in the CRMs.
These CRMs have information values for PCB homologue concentrations determined by using a Japanese official method for determination
of PCBs in wastes and densities determined with an oscillational density meter. Because oil samples having arbitrary PCB concentrations
between respective property values of the PCB-fortified and nonfortified CRMs can be prepared by gravimetric mixing of the
CRM pairs, these CRMs can be used for validation of PCB analyses using various instruments which have different sensitivities.
Figure Preparation and certification processes of the mineral oil CRMs (example shown is polychlorinated biphenyls in insulation
oil, high/low concentrations)
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
94.
Koichi Nishimura Kei-ichi Sakakura Shigeki Tachihara Yutaka Aoyagi Takeshi Kinoshita 《Tetrahedron》2007,63(21):4558-4562
Three new diterpenoids, tricalysiolide H (1) and tricalysiones A (2) and B (3), with novel structural features were isolated from the wood of Tricalysia dubia, together with a known compound, cafestol (4). The structures of 1-3 were elucidated on the basis of 2D NMR spectroscopy and X-ray crystallographic analysis. 相似文献
95.
CO2 capture and release behaviors of three amidines bearing silatranyl group in DMSO solution were evaluated under dry conditions containing a very small amount of water. A six-membered cyclic amidine with silatranyl group captured CO2 at 25 °C under atmospheric pressure quantitatively, and the trapped CO2 was released at 60 °C under Ar atmosphere. A five-membered cyclic amidine with silatranyl group also captured CO2, but less efficiently, under the same conditions as above. In contrast, an acyclic amidine with silatranyl group did not capture CO2 at all, as expected from the poor CO2-capturing ability of the acyclic amidine moiety. 相似文献
96.
Takeya J Kato J Hara K Yamagishi M Hirahara R Yamada K Nakazawa Y Ikehata S Tsukagoshi K Aoyagi Y Takenobu T Iwasa Y 《Physical review letters》2007,98(19):196804
Gate-voltage dependence of carrier mobility is measured in high-performance field-effect transistors of rubrene single crystals by simultaneous detection of the longitudinal conductivity sigma(square) and Hall coefficient R(H). The Hall mobility mu(H) (identical with sigma(square)R(H)) reaches nearly 10 cm(2)/V s when relatively low-density carriers (<10(11) cm(-2)) distribute into the crystal. mu(H) rapidly decreases with higher-density carriers as they are essentially confined to the surface and are subjected to randomness of the amorphous gate insulators. The mechanism to realize high carrier mobility in the organic transistor devices involves intrinsic-semiconductor character of the high-purity organic crystals and diffusive bandlike carrier transport in the bulk. 相似文献
97.
98.
Evaluation and comparison of layered titanate nanosheets using TOF‐SIMS and g‐ogram analysis 下载免费PDF全文
Ichiro Mihara Keizo Nakagawa Masahiro Kudo Satoka Aoyagi 《Surface and interface analysis : SIA》2015,47(7):764-770
The evaluation of nanostructure is important to develop the highly controlled nanomaterials. In this study, two kinds of layered titanate nanosheets, which were produced by using hexylamine and laurylamine, respectively, as surfactants were investigated by Gentle Secondary Ion Mass Spectrometry Gentle‐SIMS (G‐SIMS) and g‐ogram, which is the latest Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS) data analysis method for detecting more intact ions and obtaining the information on original chemical structures of samples precisely from complicated TOF‐SIMS spectra. As a result, molecular related ions of the surfactants were detected from each sample, and the structural information of samples was obtained. From both samples, surfactant molecular ions connected with hydrocarbon were detected as more intact ions rather than molecular ions of themselves. It was suggested that hydrophobic domains of their lamellar mesostructure are formed robustly by more than two surfactant molecules connected with each other linearly. After all, important information on the chemical structure of the layered titanate nanosheets, which would be difficult to be found by using typical structural analysis methods such as X‐ray diffraction and transmission electron microscopy, were obtained using G‐SIMS and g‐ogram. Therefore, it was shown that g‐ogram and G‐SIMS are helpful to evaluate the nanostructured materials. And it was also shown that g‐ogram is applicable to organic–inorganic materials which contain long hydrocarbon structures. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
99.
Aoyagi N Shimojo K Brooks NR Nagaishi R Naganawa H Van Hecke K Van Meervelt L Binnemans K Kimura T 《Chemical communications (Cambridge, England)》2011,47(15):4490-4492
Temperature-dependent yellow-to-red colour changes of uranyl thiocyanate complexes with 1-alkyl-3-methylimidazolium cations have been studied by different spectroscopic methods and this phenomenon is attributed to changes in the local environment of the uranyl ion, including the coordination number, as well as to cation-anion interactions. 相似文献
100.