246,567 research outputs found
Modeling two-state cooperativity in protein folding
A protein model with the pairwise interaction energies varying as local
environment changes, i.e., including some kinds of collective effect between
the contacts, is proposed. Lattice Monte Carlo simulations on the
thermodynamical characteristics and free energy profile show a well-defined
two-state behavior and cooperativity of folding for such a model. As a
comparison, related simulations for the usual G\={o} model, where the
interaction energies are independent of the local conformations, are also made.
Our results indicate that the evolution of interactions during the folding
process plays an important role in the two-state cooperativity in protein
folding.Comment: 5 figure
Detection of Minimum-Ionizing Particles and Nuclear Counter Effect with Pure BGO and BSO Crystals with Photodiode Read-out
Long BGO (Bismuth Germanate) and BSO (Bismuth Silicate) crystals coupled with
silicon photodiodes have been used to detect minimum-ionizing particles(MIP).
With a low noise amplifier customized for this purpose, the crystals can detect
MIPs with an excellent signal-to-noise ratio. The NCE(Nuclear Counter Effect}
is also clearly observed and measured. Effect of full and partial wrapping of a
reflector around the crystal on light collection is also studied.Comment: 18 pages, including 5 figures; LaTeX and EP
Stopping powers and cross sections due to two-photon processes in relativistic nucleus-nucleus collision
The radiation dose received from high energy galactic cosmic rays (GCR) is a limiting factor in the design of long duration space flights and the building of lunar and martian habitats. It is of vital importance to have an accurate understanding of the interactions of GCR in order to assess the radiation environment that the astronauts will be exposed to. Although previous studies have concentrated on the strong interaction process in GCR, there are also very large effects due to electromagnetic (EM) interactions. In this report we describe our first efforts at understanding these EM production processes due to two-photon collisions. More specifically, we shall consider particle production processes in relativistic heavy ion collisions (RHICs) through two-photon exchange
Photovoltage Detection of Edge Magnetoplasmon Oscillations and Giant Magnetoplasmon Resonances in A Two-Dimensional Hole System
In our high mobility p-type AlGaAs/GaAs two-dimensional hole samples, we
originally observe the B-periodic oscillation induced by microwave (MW) in
photovoltage (PV) measurements. In the frequency range of our measurements (5 -
40 GHz), the period ({\Delta}B) is inversely proportional to the microwave
frequency (f). The distinct oscillations come from the edge magnetoplasmon
(EMP) in the high quality heavy hole system. In our hole sample with a very
large effective mass, the observation of the EMP oscillations is in neither the
low frequency limit nor the high frequency limit, and the damping of the EMP
oscillations is very weak under high magnetic fields. Simultaneously, we
observe the giant plasmon resonance signals in our measurements on the shallow
two-dimensional hole system (2DHS)
A comparative analysis of the value of information in a continuous time market model with partial information: the cases of log-utility and CRRA
We study the question what value an agent in a generalized Black-Scholes model with partial information attributes to the complementary information. To do this, we study the utility maximization problems from terminal wealth for the two cases partial information and full information. We assume that the drift term of the risky asset is a dynamic process of general linear type and that the two levels of observation correspond to whether this drift term is observable or not. Applying methods from stochastic filtering theory we derive an analytical tractable formula for the value of information in the case of logarithmic utility. For the case of constant relative risk aversion (CRRA) we derive a semianalytical formula, which uses as an input the numerical solution of a system of ODEs. For both cases we present a comparative analysis
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