762 research outputs found
血液細胞の進化の足跡を単細胞生物にまで遡る
京都大学新制・論文博士博士(医学)乙第13526号論医博第2272号新制||医||1062(附属図書館)京都大学大学院医学研究科医学専攻(主査)教授 濵﨑 洋子, 教授 遊佐 宏介, 教授 篠原 隆司学位規則第4条第2項該当Doctor of Medical ScienceKyoto UniversityDFA
Reactivity Boundaries to Separate the Fate of a Chemical Reaction Associated with an Index-two saddle
Reactivity boundaries that divide the destination and the origin of
trajectories are of crucial importance to reveal the mechanism of reactions. We
investigate whether such reactivity boundaries can be extracted for higher
index saddles in terms of a nonlinear canonical transformation successful for
index-one saddles by using a model system with an index-two saddle. It is found
that the true reactivity boundaries do not coincide with those extracted by the
transformation taking into account a nonlinearity in the region of the saddle
even for small perturbations, and the discrepancy is more pronounced for the
less repulsive direction of the index-two saddle system. The present result
indicates an importance of the global properties of the phase space to identify
the reactivity boundaries, relevant to the question of what reactant and
product are in phase space, for saddles with index more than one
Reactivity Boundaries to Separate the Fate of a Chemical Reaction Associated with Multiple Saddles
Reactivity boundaries that divide the origin and destination of trajectories
are crucial of importance to reveal the mechanism of reactions, which was
recently found to exist robustly even at high energies for index-one saddles
[Phys. Rev. Lett. 105, 048304 (2010)]. Here we revisit the concept of the
reactivity boundary and propose a more general definition that can involve a
single reaction associated with a bottleneck made up of higher index saddles
and/or several saddle points with different indices, where the normal form
theory, based on expansion around a single stationary point, does not work. We
numerically demonstrate the reactivity boundary by using a reduced model system
of the cation where the proton exchange reaction takes place through a
bottleneck made up of two index-two saddle points and two index-one saddle
points. The cross section of the reactivity boundary in the reactant region of
the phase space reveals which initial conditions are effective in making the
reaction happen, and thus sheds light on the reaction mechanism.Comment: 12 pages, 7 figure
Stochastic ranking process with time dependent intensities
We consider the stochastic ranking process with the jump times of the
particles determined by Poisson random measures. We prove that the joint
empirical distribution of scaled position and intensity measure converges
almost surely in the infinite particle limit. We give an explicit formula for
the limit distribution and show that the limit distribution function is a
unique global classical solution to an initial value problem for a system of a
first order non-linear partial differential equations with time dependent
coefficients
A visual feedback system for micromanipulation with stereoscopic microscope
A stereoscopic microscope is widely used in a micromanipulation such as to operate genes and to inspect integration circuits. As in these tasks the micromanipulation is handled and makes too heavy burden to operators, it is desirable to perform the micromanipulation automatically. In this paper, we propose a visual feedback system for micromanipulation with stereoscopic microscope. This system takes less time to control the manipulator by reducing searching area to detect an object </p
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