81 research outputs found

    Non-Adiabatic Transition in Spin-Boson Model and Generalization of the Landau-Zener Formula

    Full text link
    Non-adiabatic transitions are studied in a spin-boson model with multiple scattering points. In order to generalize the Landau-Zener formula, which describes the case of a single scattering point, we define an ``effective gap'' for a set of scattering points. The generalized formula agrees very well with numerical results of the non-adiabatic dynamics, which we obtained by a direct numerical method. This will make the Landau-Zener formula yet more useful in analyzing experimental data of magnetic-moment inversion.Comment: 17 pages, 18 figure

    Two cytotoxic squalene-derived polyethers from the Japanese red alga Chondria armata

    Get PDF
    The red alga Chondria armata is known to produce and contain a rich diversity of secondary metabolites, such as domoic acid-related alkaloids and triterpene polyethers. Our investigation on red alga C. armata from Kagoshima coast, Japan, resulted in the isolation of two new triterpene polyethers, bandokorols A (1) and B (2). The structures of these compounds were determined based on spectroscopic data such as infrared (FTIR), 1H-NMR, APT, 1H–1H-COSY, HSQC, HMBC, NOESY and FAB mass spectrometry (HRFABMS). The anticancer potentials of these compounds were tested against adult T-cell leukaemia (ATL), S1T cells and their IC50 values are reported here

    External iliac venous aneurysm in a pregnant woman: a case report

    Get PDF
    AbstractWe report an external iliac venous aneurysm in a young pregnant woman who was diagnosed incidentally by ultrasound scanning. The aneurysm was successfully treated by tangential aneurysmectomy and lateral venorrhaphy. Primary iliac venous aneurysm is a rare vascular abnormality. The clinical significance of the disease is unknown. However, embolism, rupture, and thrombosis might occur as they can occur with popliteal venous aneurysm. In fact, three of four reported patients with iliac venous aneurysms had a thromboembolic event. For those reasons, prophylactic treatment is indicated. This is the first patient with an iliac venous aneurysm to be diagnosed without complication

    Probabilistic Interpretation of Resonant States

    Full text link
    We provide probabilistic interpretation of resonant states. This we do by showing that the integral of the modulus square of resonance wave functions (i.e., the conventional norm) over a properly expanding spatial domain is independent of time, and therefore leads to probability conservation. This is in contrast with the conventional employment of a bi-orthogonal basis that precludes probabilistic interpretation, since wave functions of resonant states diverge exponentially in space. On the other hand, resonant states decay exponentially in time, because momentum leaks out of the central scattering area. This momentum leakage is also the reason for the spatial exponential divergence of resonant state. It is by combining the opposite temporal and spatial behaviors of resonant states that we arrive at our probabilistic interpretation of these states. The physical need to normalize resonant wave functions over an expanding spatial domain arises because particles leak out of the region which contains the potential range and escape to infinity, and one has to include them in the total count of particle number.Comment: 11 pages, 5 figures, to appear in Pramana Journal of Physics as an article in the proceedings of Homi Bhabha Centenary Conference on Non-Hermitian Hamiltonians in Quantum Physics PHHQP VIII; this version are with added references as well as some rewording after reviewer's suggestion
    corecore