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941.
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
942.
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
943.
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
944.
A highly sensitive and simple reversed phase high performance liquid chromatographic (HPLC) method for the quantitative determination of free fatty acids in human serum is presented. The method is based on the direct derivatization of serum fatty acids with 6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone-3-propionylcarboxylic acid hydrazide. The derivatization reaction proceeds in aqueous solution in the presence of pyridine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at 37 degrees C. The resulting derivatives are separated within 75 min on a reversed phase column (YMC Pack C8) with a gradient elution of aqueous acetonitrile and detected fluorimetrically. The detection limits are 2.5-5 fmol in a 10 microL injection volume. The sensitivity permits precise determination of free fatty acids in 5 microL serum. The method is simple and is without the conventional liquid-liquid extraction steps of serum fatty acids. 相似文献
945.
946.
A. Uedono S. Watauchi Y. Ujihira L. Wei S. Tanigawa R. Suzuki H. Ohgaki T. Mikado H. Kametani H. Akiyama Y. Yamaguchi M. Koumaru 《Hyperfine Interactions》1993,79(1-4):621-625
Defects in the separation by implanted oxygen (SIMOX) wafers were studied by monoenergetic positron beams. For the as-implanted specimen, vacancies introduced by ion implantation were found to form vacancy-oxygen complexes. After high temperature annealing, a drastic increase in the formation probability of positronium was observed. This suggests an introduction of open-spaces by the formation of an amorphous SiO2. The present investigation shows that positrons provide a nondestructive probe for the detection of defects in SIMOX wafers and microstructures of SiO2. 相似文献
947.
948.
M. Nakano H. Fujita M. Takahata S. Kiribayashi K. Yamaguchi 《International journal of quantum chemistry》2001,84(6):649-659
We investigate the microscopic third‐order nonlinear optical properties, i.e., the second hyperpolarizabilities (γ), of two different sizes of molecular aggregates with a dendritic, i.e., Bethe‐lattice, structure. One possesses a nonfractal structure, while the other has a fractal structure. The aggregate is treated in a two‐exciton model composed of two‐state monomers coupled to each other by the dipole–dipole interaction. The off‐resonant γ of the aggregates are calculated by the numerical Liouville approach, including relaxation effects. The total γ value is partitioned into the contribution of virtual exciton generation, and its spatial contribution to γ is analyzed in relation to the virtual excitation processes in the perturbation theory. It is found that the intermolecular‐interaction effect enhances both one‐ and two‐exciton‐generation contributions, while the relaxation effect reduces those, although the one‐ and two‐exciton‐generation contributions have mutually opposite signs. From the comparison of spatial contributions to γ between the nonfractal and fractal aggregates, an enhancement of the contribution to γ from the periphery to the core is observed in the fractal structure, while such a feature is not observed in the nonfractal structure. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 相似文献
949.
张高龙 叶沿林 江栋兴 郑涛 李智焕 李湘庆 吴翠娥 陈志强 胡青元 庞丹阳 王佳 A.Ozawa Y.Yamaguchi R.Kanungo D.Fang I.Tanihata 《中国物理 C》2005,29(10):940-943
在25MeV/u 6He轰击9Be靶的反应中,用探测器望远镜测得氚碎片,得到了5个角度的能谱,经过仔细的分析取得了高能直接破碎成分的角分布.利用Serber模型进行了破碎反应的理论计算,证实了实验中高能成分的t来自于6He的直接破碎反应.利用Fermi破碎模型计算了6He中各破碎反应道基于相空间的百分比产额,进而估算出6He初态中t+t结构的概率约占1/3, 而4He核心加价中子的组态约占2/3. 相似文献
950.
The authors discuss a method for estimating and/or predicting the listening score and two psychological impressions of speech audibility and annoyance, when listening to audio signals, in an actual noise environment. The method introduced the instantaneous spectral distance that reflects the relationship between the spectral level of the speech peaks and that of noise within a short time scale. The validity and the applicability of the proposed method were confirmed experimentally, and reasonable results were obtained. Specifically, it is necessary to predict a psychological impression of the noise as a whole over a long period of time, after a certain amount of exposure to noise, taking the period of higher sound pressure level of the noise into consideration. 相似文献