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101.
Akira Sakakura Kouichi Suzuki Hirotaka Katsuzaki Takashi Komiya Toshikatsu Imamura Yasuo Aizono Kunio Imai 《Tetrahedron letters》2005,46(52):9057-9059
The ‘Hanasanagitake’ mushroom, Isaria japonica, is a folk medicine and a traditional health food. Fractionation of the 60% ethanol extract of the mushroom, guided by the antioxidant activity test, led to the isolation of a new pseudo-di-peptide, and it was called ‘hanasanagin’. Spectral analysis and chemical transformation determined the structure of hanasanagin as 3,4-diguanidinobutanoyl-DOPA. 相似文献
102.
Noriyuki Uchida Tsuyoshi Okami Hideo Tagami Naoki Fukata Masanori Mitome Yoshio Bando Kouichi Murakami 《Physica E: Low-dimensional Systems and Nanostructures》2007,38(1-2):31
The effects of aluminum (Al-) doping in SiO2 film containing silicon-nanocrystal (nc-Si) dots were investigated by photoluminescence (PL) and electron spin resonance (ESR) measurements. The observed PL peak center showed a blueshift due to reduction of size of nc-Si dots as a result of the Al doping followed by annealing within a range of 600–800 °C. For the samples annealed at 1000 °C, the PL intensity showed increases with increasing concentration of Al atoms in the SiO2. The ESR results obtained from all the samples, however, revealed that the density of defects causing the PL quenching did not show decrease by the Al doping. Therefore, the enhancement of the PL intensity by the Al doping seemed to be caused probably by the increase in the density of nc-Si dots. 相似文献
103.
104.
Dimerization of planarized diamine 2 using benzoyl peroxide gave dihydrazine 1 in about 70% yield; that is, three dehydrogenations (one CC- and two NN-homocouplings) and two ring closures were attained in one synthetic step. Dihydrazine 1 may be viewed as a chiral pi-conjugated conjoined double helicene, with two homochiral [5]helicene-like fragments, annelated in their mid-sections. A relatively high barrier of approximately 35 kcal mol-1 for inversion of configuration for one of the [5]helicene-like helices in 1 was found. 相似文献
105.
Kouichi Murakami 《Journal of Mathematical Analysis and Applications》2005,310(2):492-505
We give some new criteria to determine the stability of a non-hyperbolic fixed point of the scalar difference equation where and f is a sufficient smooth function. Our results are based on higher order derivative at a fixed point of . 相似文献
106.
Hirata H Itoh T Hosokawa K Deng Y Susaki H 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,175(2):177-184
This article describes a systematic method for determining the cutoff frequency of the low-pass window function that is used for deconvolution in two-dimensional continuous-wave electron paramagnetic resonance (EPR) imaging. An evaluation function for the criterion used to select the cutoff frequency is proposed, and is the product of the effective width of the point spread function for a localized point signal and the noise amplitude of a resultant EPR image. The present method was applied to EPR imaging for a phantom, and the result of cutoff frequency selection was compared with that based on a previously reported method for the same projection data set. The evaluation function has a global minimum point that gives the appropriate cutoff frequency. Images with reasonably good resolution and noise suppression can be obtained from projections with an automatically selected cutoff frequency based on the present method. 相似文献
107.
Kouichi Yamaguchi Takeshi Wada Shinsaku Maruyama Masaaki Takehisa 《Journal of Polymer Science.Polymer Physics》1973,11(8):1573-1584
The molecular weight distribution of polyethylene produced by radiation was calculated according to a kinetic scheme. The calculated molecular weight distribution was compared with the results deduced from gel-permeation chromatography. The observed distribution curve from GPC was broader and showed a lower degree of polymerization than the calculated one. Discrepancies between observed and calculated curves can be explained if the polymer contains nonsteady-state products and if the reaction mechanism includes chain transfer to dead polymer. By this reaction long-chain branching would occur. Several long-chain branches per polymer molecule were indeed found, as inferred from solution properties. 相似文献
108.
Takeda Y Yoshino T Uoto K Terasawa H Soga T 《Chemical & pharmaceutical bulletin》2002,50(10):1398-1400
A new method for the synthesis of 7-deoxytaxane analogues has been established through hydrogenation of Delta(6,7)-taxane derivatives. Among several catalysts examined, Pd-C was found to be a most effective catalyst for the preparation of target compound. 相似文献
109.
Real-root property of the spectral polynomial of the Treibich–Verdier potential and related problems
Zhijie Chen Ting-Jung Kuo Chang-Shou Lin Kouichi Takemura 《Journal of Differential Equations》2018,264(8):5408-5431
We study the spectral polynomial of the Treibich–Verdier potential. Such spectral polynomial, which is a generalization of the classical Lamé polynomial, plays fundamental roles in both the finite-gap theory and the ODE theory of Heun's equation. In this paper, we prove that all the roots of such spectral polynomial are real and distinct under some assumptions. The proof uses the classical concept of Sturm sequence and isomonodromic theories. We also prove an analogous result for a polynomial associated with a generalized Lamé equation, where we apply a new approach based on the viewpoint of the monodromy data. 相似文献
110.
Yamane Y Sasage K An T Harii K Ohe J Ieda J Barnes SE Saitoh E Maekawa S 《Physical review letters》2011,107(23):236602
We study, both experimentally and theoretically, the generation of a dc spinmotive force. By exciting a ferromagnetic resonance of a comb-shaped ferromagnetic thin film, a continuous spinmotive force is generated. Experimental results are well reproduced by theoretical calculations, offering a quantitative and microscopic understanding of this spinmotive force. 相似文献