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961.
Matsuta K. Fukuda M. Tanigaki M. Minamisono T. Nojiri Y. Akai H. Izumikawa T. Nakazato M. Mihara M. Yamaguchi T. Harada A. Sasaki M. Miyake T. Onishi T. Minamisono K. Fukao T. Sato K. Matsumoto Y. Ohtsubo T. Fukuda S. Yoshida K. Ozawa A. Momota S. Kobayashi T. Tanihata I. Alonso J. R. Krebs G. F. Symons T. J. M. 《Hyperfine Interactions》1996,97(1):501-508
The spin relaxation timeT
1 for short-lived beta emitters13O and23Mg implanted in Pt have been measured for the first time;T
1T13O) = 2.90 ±0.65 Ks andT
1
T(23Mg) = 1665 ±140 Ks. The Knight shift for13O in Pt was measured at 300 K to beK(13O) = +(4.23 ±0.14) × 10–3. In the case of13O, the Knight shift is unusually large and the relaxation time is unusually fast compared with other interstitial impurities in Pt. A KKR band-structure calculation reproduces the present large Knight shift fairly well. 相似文献
962.
Moriyuki Sato Atsushi Nakashima Yuzuru Sato Isao Yamaguchi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6688-6702
Novel liquid crystalline (LC) hyperbranched (HB) polyesters comprising phenylbenzothiazole (PBT) unit as mesogen in the interiors were prepared at various feed mole ratios (A2/B3) by solution polycondensation of a dioxydiundecanol derivative of PBT (A2 monomer) with trimesic acid trimethyl ester (B3 monomer) via A2+B3 approach and their LC and optical properties were investigated. Analogous linear polyesters containing the PBT unit in the main chains were also prepared by the solution polycondensation of A2 monomer with aromatic or aliphatic dimethyl esters. FTIR and 1H‐NMR spectroscopies indicated that the HB polyesters are produced without gelation during the polycondensation and have degree of branching (DB) of 7–46%. The structures of HB polymers changed depending on the feed mole ratios and the polymer prepared in the mole ratio of A2/B3 = 3/2 had the highest inherent viscosity and DB. Acetylation of terminal OH group‐having HB polyesters prepared in excess mole ratios of A2/B3 afforded ones bearing acetoxy groups in the terminals. DSC measurements, polarizing microscope observations of textures, and X‐ray analyses suggested that only the terminal OH group‐having HB polymer prepared in the mole ratio of A2/B3 = 3/1 form smectic C phase. In the linear polymers, the polymers derived by using the aromatic dimethyl esters had no LC melt, but those from the aliphatic dimethyl esters formed LC smectic C phase. The acetoxy group‐bearing HB polymers showed more stable smectic A or C phase than those with the OH terminals. Solution UV‐vis and photoluminescent (PL) spectra indicated that the linear and the HB polymers have analogous optical properties and display maximum absorbances and blue‐light emission on the basis of the PBT unit, where the Stokes shifts were observed because of intermolecular aggregation effects, but there is a large difference between the optical behaviors of the linear and the HB polymers in film, whose Eg values of the linear polymers decreased and those of the HB polymers vice versa. Quantum efficiencies (Φ) had a tendency of increase in the linear polymers and the HB polymers forming LC phases. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6688–6702, 2008 相似文献
963.
The stress relaxation under large step equibiaxial elongation for low‐density polyethylene with long‐chain branches revealed that the time‐strain separability holds in relaxation modulus GB(t, εB), and damping function hB(εB) exhibits weaker equibiaxial elongational strain εB dependence than that predicted by the Doi–Edwards theory without the independent alignment approximation. Dependencies of damping function h(γ) for step shear deformation and hB(εB) on stretch ratio α of polymer contour length and orientation of a polymer chain in direction of the maximum orientation were evaluated, and it was found that the α dependencies of h(γ) and hB(εB) are different, whereas dependencies of h(γ) and hB(εB) on the orientation coincide fairly well. These results indicate that the damping is dominated by the chain orientation rather than α. This implies that withdrawal of long‐chain branches into tube of a backbone chain occurs when the orientation of the long‐chain branches is large and friction force against the branch point withdrawal is small. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1275–1284, 2009 相似文献
964.
Endotoxins from four bacterial species extracted by three different procedures were acid-methanolyzed and the methyl esters of the fatty acids were analyzed by packed-column gas chromatography. There were qualitative and quantitative differences in the fatty acid profiles of the lipopolysaccharides isolated from four Gram-negative bacteria. Our data show considerable lot-to-lot variations in amounts of four methyl esters from the same bacterial serotype extracted by the same procedure and in the same bacterial serotype extracted by different procedures. These results indicate that extraction and perhaps culture conditions, as well as bacterial species, affect the fatty acid composition of endotoxins, hydrolyzed and derivatized by these procedures. 相似文献
965.
T. Iwashita I. Kanazawa T. Oguchi M. Yamaguchi K. Tokumitsu 《Hyperfine Interactions》1993,78(1-4):527-534
Time differential perturbed angular correlation spectra of the amorphous Fe57Hf43 alloy prepared by mechanical alloying (MA) andthe intermetallic compounds FeHf2 were measured. The short-range structures in amorphous Fe57Hf43 andintermetallic compounds of FeHf2 andFe2Hf are compared from a microscopic point of view. 相似文献
966.
H. Matsubara Y. Yamamoto I. Kanazawa T. Iwashita Y. Ito S. Takamura A. Yamaguchi We -Hyo Soe R. Yamamoto 《Hyperfine Interactions》1994,84(1):159-164
We report on the results of depth-profiling experiments of multilayers of Cu-Hf using a slow position beam. Experimental data reveal that the Hf layers contain many open-volume type defects and that there might be thin oxidized Hf that reduces theS parameter in the interfaces between Cu-Hf. 相似文献
967.
Seiji Yamaguchi Yosbihiko Sugioka Miwa Ishida Hajime Yokoyama Yoshiro Hirai 《Journal of heterocyclic chemistry》1997,34(4):1329-1334
Diethyl 5-isopropenyl-4,5-dihydrofuran-2,3-dicarboxylate 1a and methyl 5-isopropenyl-3-methoxy-carbonyl-4,5-dihydrofuran-2-acetate 2a were prepared by cylization of diethyl 2-oxosuccinate or dimethyl 3-oxoglutarate with (E)-1,4-dibromo-2-methyl-2-butene. Their chemical properties were studied. 相似文献
968.
Tadashi Asanuma Hideaki Oikawa Yuuichi Ookawa Wataru Yamasita Mitunori Matsuo Akihiro Yamaguchi 《Journal of polymer science. Part A, Polymer chemistry》1994,32(11):2111-2118
Thermotropic liquid crystal polyimide which has neither an ester linkage nor a carbonate linkage was prepared by the polymerization of 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA) and 1,3-bis[4-(4′-aminophenoxy)cumyl)]benzene (BACB). This polyimide shows the liquid crystal phase at 549-593 K. Mixing this liquid crystal polyimide or copolymerizing BACB decreases the melt viscosity of the thermoplastic polyimide (Aurum). © 1994 John Wiley & Sons, Inc. 相似文献
969.
W. J. Agnew W. Böttger F. Feigl J. M. Kolthoff L. Michaelis S. Yamaguchi A. Martini L. Rosenthaler J. Kapulitzas F. Fröhnke R. Nakaseko Matsuy G. Denigès A. Benedetti-Pichler F. Schneider Hilde Thurnwald L. de Brouckère E. Belcke E. W. Schwartze R. M. Hann J. H. Yoe W. L. Hill J. L. Steenkamp K. Heller P. Krumholz R. Montequi W. H. Hammond R. Ripan G. Lode Fr. Hecht und W. Reich-Rohrwig 《Fresenius' Journal of Analytical Chemistry》1932,88(3-4):128-136
Ohne Zusammenfassung 相似文献
970.
W. J. Agnew W. Böttger F. Feigl J. M. Kolthoff L. Michaelis S. Yamaguchi A. Martini L. Rosenthaler J. Kapulitzas F. Fröhnke R. Nakaseko Matsuy G. Denigès A. Benedetti-Pichler F. Schneider Hilde Thurnwald L. de Brouckère E. Belcke E. W. Schwartze R. M. Hann J. H. Yoe W. L. Hill J. L. Steenkamp K. Heller P. Krumholz R. Montequi W. H. Hammond R. Ripan G. Lode Fr. Hecht W. Reich-Rohrwig 《Analytical and bioanalytical chemistry》1932,88(3-4):128-136