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71.
A heat-pulse modulation technique has been applied to the phosphorescence study of xanthone in n-pentane at 1.5 and 4.2 K. The heat-pulse induced delayed phosphorescence (HIDP) was observed via the internal and back-internal conversion processes among the phosphorescent levels. Decay properties were examined as a function of pulse-delay time. 相似文献
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Ohwada K Fujii Y Takesue N Isobe M Ueda Y Nakao H Wakabayashi Y Murakami Y Ito K Amemiya Y Fujihisa H Aoki K Shobu T Noda Y Ikeda N 《Physical review letters》2001,87(8):086402
The "devil's staircase"-type phase transition in the quarter-filled spin-ladder compound NaV2O5 has been discovered at low temperature and high pressure by synchrotron radiation x-ray diffraction. A large number of transitions are found to successively take place among higher-order commensurate phases with 2a x 2b x zc type superstructures. The observed temperature and pressure dependence of modulation wave number q(c), defined by 1/z, is well reproduced by the axial next nearest neighbor Ising model. The q(c) is suggested to reflect atomic displacements presumably coupled with charge ordering in this system. 相似文献
74.
Takashi Amemiya 《Applied mathematics and computation》2001,120(1-3):45-54
The uncertain linear systems with time-varying delays and limited measurable states variables are shown to have special configuration, called triangular configuration, to be stabilizable by means of state variable feedback controller. This configuration indicates the location of uncertainties among system parameters including input and output coefficients. 相似文献
75.
Ishimatsu R Izadyar A Kabagambe B Kim Y Kim J Amemiya S 《Journal of the American Chemical Society》2011,133(40):16300-16308
Here, we report on the first electrochemical study that reveals the kinetics and molecular level mechanism of heterogeneous ion-ionophore recognition at plasticized polymer membrane/water interfaces. The new kinetic data provide greater understanding of this important ion-transfer (IT) process, which determines various dynamic characteristics of the current technologies that enable highly selective ion sensing and separation. The theoretical assessment of the reliable voltammetric data confirms that the dynamics of the ionophore-facilitated IT follows the one-step electrochemical (E) mechanism controlled by ion-ionophore complexation at the very interface in contrast to the thermodynamically equivalent two-step electrochemical-chemical (EC) mechanism based on the simple transfer of an aqueous ion followed by its complexation in the bulk membrane. Specifically, cyclic voltammograms of Ag(+), K(+), Ca(2+), Ba(2+), and Pb(2+) transfers facilitated by highly selective ionophores are measured and analyzed numerically using the E mechanism to obtain standard IT rate constants in the range of 10(-2) to 10(-3) cm/s at both plasticized poly(vinyl chloride) membrane/water and 1,2-dichloroethane/water interfaces. We demonstrate that these strongly facilitated IT processes are too fast to be ascribed to the EC mechanism. Moreover, the little effect of the viscosity of nonaqueous media on the IT kinetics excludes the EC mechanism, where the kinetics of simple IT is viscosity-dependent. Finally, we employ molecular level models for the E mechanism to propose three-dimensional ion-ionophore complexation at the two-dimensional interface as the unique kinetic requirement for the thermodynamically facilitated IT. 相似文献
76.
Toshikazu Kaise Yoshiya Horiguchi Shozo Fukui Kazuo Shiomi Makoto Chino Takeaki Kikuchi 《应用有机金属化学》1992,6(4):369-373
The acute toxicity of arsenocholine was examined in mice by oral administration and intravenous injection. The LD50 values of arsenocholine were 6.5 g kg?1 for oral administration and 187 mg kg?1 for oral administration and 187 mg kg?1 for intravenous injection. Decreases of respiration and spontaneous motility were observed in the mice dosed orally at 12 g kg?1. The animals exhibited ataxia and finally showed paralysis of the hind legs within 20 min of administration. When arsenocholine was administered orally to mice at 5 or 50 mg As kg?1, the greater part of the arsenic administered was recovered in urine within 96 h. The metabolite of arsenocholine in urine was identified as arsenobetaine by high-performance liquid chromatography-inductively coupled plasma emission spectrometry (HPLC ICP) and fast atom bombardment mass spectrometry (FAB MS). These results suggested that the major part of orally administered arsenocholine was absorbed from the gastrointestinal tract in mice and then rapidly excreted in urine with biotransformation. 相似文献
77.
Kuniaki Tatsuta Yoshiya Amemiya Shunji Maniwa Mitsuhiro Kinoshita 《Tetrahedron letters》1980,21(29):2837-2840
The stereospecific total synthesis of macrolide antibiotics, carbomycin B and josamycin (leucomycin A3), is described. The key aglycone has been synthesized by coupling two segments of C1–C10 and C11–C16 portions, which are stereospecifically derived from glucose. 相似文献
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