81 research outputs found
Non-Adiabatic Transition in Spin-Boson Model and Generalization of the Landau-Zener Formula
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
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
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
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
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