10,300 research outputs found
Extracting Functional Modules from Biological Pathways
It has been proposed that functional modules are the fundamental units of cellular function. Methods to identify these modules have thus far relied on gene expression data or protein-protein interaction (PPI) data, but have a few limitations. We propose a new method, using biological pathway data to identify functional modules, that can potentially overcome these limitations. We also construct a network of these modules using functionally relevant PPI data. This network displays the flow and integration of information between modules and can be used to map cellular function
Fast ground-state cooling of mechanical resonator with time-dependent optical cavities
We propose a feasible scheme to cool down a mechanical resonator (MR) in a
three-mirror cavity optomechanical system with controllable external optical
drives. Under the Born-Oppenheimer (BO) approximation, the whole dynamics of
the mechanical resonator and cavities is reduced to that of a time-dependent
harmonic oscillator, whose effective frequency can be controlled through the
optical driving fields. The fast cooling of the MR can be realized by
controlling the amplitude of the optical drives. Significantly, we further show
that the ground-state cooling may be achieved via the three-mirror cavity
optomechanical system without the resolved sideband condition.Comment: Some references including our previous works on cooling of mechanical
resonators are added, and some typos are corrected in this new version.
Comments are welcom
Nondeterminstic ultrafast ground state cooling of a mechanical resonator
We present an ultrafast feasible scheme for ground state cooling of a
mechanical resonator via repeated random time-interval measurements on an
auxiliary flux qubit. We find that the ground state cooling can be achieved
with \emph{several} such measurements. The cooling efficiency hardly depends on
the time-intervals between any two consecutive measurements. The scheme is also
robust against environmental noises.Comment: 4 pages, 3 figure
Production of large transverse momentum dileptons and photons in , and collisions by photoproduction processes
The production of large dileptons and photons originating from
photoproduction processes in , and collisions is calculated. We
find that the contribution of dileptons and photons produced by photoproduction
processes is not prominent at RHIC energies. However, the numerical results
indicate that the modification of photoproduction processes becomes evident in
the large region for , and collisions at LHC energies.Comment: 10 figure
Effects of laser fluence on silicon modification by four-beam laser interference
This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm, 495 mJ/cm, and 637 mJ/cm, the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7-9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications
Quantum criticality in a generalized Dicke model
We employ a generalized Dicke model to study theoretically the quantum
criticality of an extended two-level atomic ensemble interacting with a
single-mode quantized light field. Effective Hamiltonians are derived and
diagonalized to investigate numerically their eigenfrequencies for different
quantum phases in the system. Based on the analysis of the eigenfrequencies, an
intriguing quantum-phase transition from a normal phase to a superradiant phase
is revealed clearly, which is quite different from that observed with a
standard Dicke model.Comment: 6 pages, 3 figure
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