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71.
Kiyohide Matsui Etsuko Tobita Kikuo Sugimoto Kiyosi Kondo Toru Seita Akira Akimoto 《应用聚合物科学杂志》1986,32(3):4137-4143
Anion exchange membranes with excellent durability were prepared by chemical modification of Nafion. The modification was achieved by transformation of the sulfonic acid group into quaternary ammonium group. Namely, Nafion membrane was first converted into an amide-type membrane. Reduction of the carbonxyl group to methylene followed by quaternarization with alkyl iodide resulted in the formation of an anion exchange membrane. The electric resistance of the resulting membranes depends on the equivalent weight of the starting membranes (4.4–6.0 Ω cm2 in 0.5N NaCl). The characteristics of the membranes are the excellent stability toward chemical substances such as organic solvents, oxidizing agents, acids, etc. For example, the membranes are stable in aqueous saturated chlorine solution at 60°C for 1000 hr. 相似文献
72.
The dynamic moduli, E′ and E″, and tan δ for PET–CR, PET–EPDM, and PET–UR composites with unidirectional short fibers were studied as a function of temperature by using a Rheovibron. The temperature dependence of tan δ showed three peaks for PET–elastomer composites. The peaks at the low temperature corresponded to the main dispersion of the respective matrixes and the peak at about 140°C to the α-dispersion of PET fiber. A small and broad peak observed at a temperature between 60 and 120°C may be caused by the relaxation of the interface region between fibers and matrix. The longitudinal storage modulus for the composite E was given by the parallel model as \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E'}_\parallel = V_f \cdot E'_f + V_m \cdot E'_m $\end{document}, where E and E are the storage moduli for fiber and matrix and Vf and Vm are the volume fraction of fiber and matrix, respectively. In the transverse direction of fibers, the composite modulus E was expressed by the logarithmic law of mixing as follows: \documentclass{article}\pagestyle{empty}\begin{document}$ \log E'_ \bot = V_f \cdot \log E'_f + V_m \cdot \log E'_m $\end{document}. The peak values of tan δ from the main dispersion of the respective matrixes were given by the equation, (tan δ⊥max)c/(tan δmax)m 1 ? β · Vf, where (tan δ⊥max)c and (tan δmax)m are the maximum values of the loss tangent for the composite and matrix, respectively, and β is coefficient depending on matrix's type. The β value of PET–CR composite is the largest one among those of the composites. 相似文献
73.
Ryuta Shigefuku Hideaki Takahashi Hiroyasu Nakano Tsunamasa Watanabe Kotaro Matsunaga Nobuyuki Matsumoto Masaki Kato Ryo Morita Yousuke Michikawa Tomohiro Tamura Tetsuya Hiraishi Nobuhiro Hattori Yohei Noguchi Kazunari Nakahara Hiroki Ikeda Toshiya Ishii Chiaki Okuse Shigeru Sase Fumio Itoh Michihiro Suzuki 《International journal of molecular sciences》2016,17(9)
The progression of chronic liver disease differs by etiology. The aim of this study was to elucidate the difference in disease progression between chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) by means of fibrosis markers, liver function, and hepatic tissue blood flow (TBF). Xenon computed tomography (Xe-CT) was performed in 139 patients with NAFLD and 152 patients with CHC (including liver cirrhosis (LC)). The cutoff values for fibrosis markers were compared between NAFLD and CHC, and correlations between hepatic TBF and liver function tests were examined at each fibrosis stage. The cutoff values for detection of the advanced fibrosis stage were lower in NAFLD than in CHC. Although portal venous TBF (PVTBF) correlated with liver function tests, PVTBF in initial LC caused by nonalcoholic steatohepatitis (NASH-LC) was significantly lower than that in hepatitis C virus (C-LC) (p = 0.014). Conversely, the liver function tests in NASH-LC were higher than those in C-LC (p < 0.05). It is important to recognize the difference between NAFLD and CHC. We concluded that changes in hepatic blood flow occurred during the earliest stage of hepatic fibrosis in patients with NAFLD; therefore, patients with NAFLD need to be followed carefully. 相似文献
74.
Thermal conductivity analysis using three‐dimensional microstructures of gelation freezing derived cellular mullite 下载免费PDF全文
Manabu Fukushima Hideki Hyuga Chika Matsunaga Yu‐Ichi Yoshizawa 《Journal of the American Ceramic Society》2018,101(8):3266-3270
The relationship between thermal conductivity and unidirectional cellular mullite microstructures created with the freeze casting route is discussed using actual three‐dimensional (3D) images, in which a homogenization method was conducted with microscopic models created from 3D images, the temperature variation in macroscopic models by the finite element method (FEM), and local heat conduction in microscopic models. The simulation results were consistent with the experimental results. This image‐based modeling technique was thus confirmed to be a strong tool for the prediction of various thermal properties of porous ceramics. 相似文献
75.
Minako Nagamori Taro Shimonosono Soichiro Sameshima Yoshihiro Hirata Naoki Matsunaga Yoshio Sakka 《Journal of the American Ceramic Society》2009,92(S1):S117-S121
A thin film (60 μm thick) of a gadolinium-doped ceria (GDC) electrolyte was prepared by the doctor blade method. This film was laminated with freeze-dried 42 vol% NiO–58 vol% GDC mixed powder and pressed uniaxially or isostatically under a pressure of 294 MPa. This laminate was cosintered at 1100 °–1500 °C in air for 4–12 h. The laminate warped because of the difference in the shrinkage of the electrolyte and electrode during the sintering. A higher shrinkage was measured for the electrode at 1100 °–1200 °C and for the electrolyte at 1300 °–1500 °C. The increase of the thickness of anode was effective in decreasing the warp and in increasing the density of the laminated composite. The maximum electric power density with a SrRuO3 cathode using 3 vol% H2 O-containing H2 fuel was 100 mW/cm2 at 600 °C and 380 mW/cm2 at 800 °C, respectively, for the anode-supported GDC electrolyte with 30 μm thickness. 相似文献
76.
Koichi Mitsukura Hiromu Sakamoto Haruka Kubo Toyokazu Yoshida Toru Nagasawa 《Journal of Bioscience and Bioengineering》2010,109(6):550-553
To efficiently produce 1,3-adamantanediol (1,3-ad(OH)2) from 1-adamantanol (1-adOH), our stocks of culture strains and soil microorganisms were surveyed for hydroxylation activity towards 1-adOH. Among them, the soil actinomycete SA8 showing the highest hydroxylation activity was identified as Streptomyces sp. based on 16S ribosomal DNA sequence analysis. The reaction products were purified by silica gel column chromatography, and from NMR and MS analyses, they were identified as 1,3-ad(OH)2 and 1,4-ad(OH)2. Streptomyces sp. SA8 produced 5.9 g l? 1 1,3-ad(OH)2from 6.2 g l? 1 1-adOH in culture broth after 120 h at 25 °C. Using resting cells, 2.3 g l? 1 1,3-ad(OH)2 was produced after 96 h of incubation at a 69% conversion rate. In both cases, 1,4-ad(OH)2 was formed as a byproduct at a rate of about 15%. Strain SA8 also hydroxylated 2-adamantanol and 2-methyl-2-adamantanol. 相似文献
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80.
V. A. Shvarts K. J. Kless N. Matsunaga E. D. Adams J. S. Xia E. A. Schuberth 《Journal of Low Temperature Physics》2002,126(1-2):169-178
Simultaneous measurements of magnetic susceptibility from 0.5 to 10 mK and pressure from 2.88 to 3.54 MPa have been made in
3
He nano-clusters embedded in a
4
He matrix, following phase separation. The susceptibility of the 3.54 MPa, all-solid sample behaves similarly to that of bulk
3
He for v=21.3 cm
3
/mole, with a Weiss constant =–250K. For the 2.88 MPa, liquid-droplet sample, =140K, indicating a ferromagnetic tendency, similar to 2-D films at some coverages. At intermediate pressures, has a peak near 1.05 mK, but without a discontinuity. For all samples, had a solid-like contribution to the lowest temperatures. Magnetic ordering in nano-clusters appears to be different than the U2D2 phase of bulk
3
He. 相似文献