Results 231 to 240 of about 136,054 (268)

Frequency Dependence of Sonophoresis

Pharmaceutical Research, 2001
Application of low-frequency ultrasound has been shown to increase skin permeability, thereby facilitating delivery of macromolecules (low-frequency sonophoresis). In this study, we sought to determine the dependence of low-frequency sonophoresis on ultrasound frequency, intensity and energy density.Pig skin was exposed to low-frequency ultrasound over
A, Tezel, A, Sens, J, Tuchscherer, S, Mitragotri   +3 more
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Frequency-Dependent Streaming Potentials

Journal of Colloid and Interface Science, 2001
An experimental apparatus and data acquisition system was constructed to measure the streaming potential coupling coefficients as a function of frequency. The purpose of the experiments was to measure, for the first time, the real and imaginary portion of streaming potentials.
Reppert, Philip, Morgan, Dale, Lesmes, David, Jouniaux, Laurence   +3 more
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Frequency dependence of resonant tunneling

AIP Conference Proceedings, 1990
The time scale in coherent resonant tunneling is investigated by calculating the Ohmic conductance versus frequency, in one-dimensional single-electron terms, for a resonant-tunneling diode. When the Fermi level is at the resonance energy, the conductance rolls off near the frequency equal to (resonance width)/(Planck’s constant).
Carlo Jacoboni, Peter J. Price
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Frequency dependence and competition

Philosophical Transactions of the Royal Society of London. B, Biological Sciences, 1988
Abstract Intraspecific competition implies interaction among the individuals of a population, so natural selection on genotypic variation in characters related to the competition will necessarily be frequency dependent. Intraspecific antagonistic competition exhibits properties similar to other behavioural interactions between ...
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Frequency dependence in acupuncture manipulations

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2009
The internal frequencies of chain network of FHN neurons include two different frequencies, namely, the intrinsic and Canard frequency. When the frequency of external stimuli approaches to the values of these two frequencies, signal processing in the chain will be enhanced.
Wenjie, Si, Jiang, Wang, Yanqiu, Che, Xile, Wei, Feng, Dong   +4 more
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Frequency dependent hyperpolarizabilities of polyynes

The Journal of Chemical Physics, 1993
Ab initio calculations have been performed for the static and dynamic polarizability and hyperpolarizability for a series of polyynes C2nH2 using self-consistent field (SCF) (n=1–6) and multiconfiguration self-consistent field (MCSCF) (n=1–4) wave functions.
JASZUNSKI, M, JORGENSEN, P, KOCH, H, AGREN, H, HELGAKER, T   +4 more
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Frequency-Dependent Sampling Linearity

IEEE Transactions on Circuits and Systems I: Regular Papers, 2009
A novel model predicts tracking nonlinearity (NL) in the form of harmonic distortion (HD) for weakly nonlinear (i.e., SFDR > 30 dBc) first-order open-loop sampling circuits. The mechanisms for the NL are exponential settling, amplitude modulation, phase modulation, and discrete-time modulation.
Thomas William Brown, Mikko Hakkarainen, Terri S. Fiez   +2 more
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Frequency-Dependent Choice, Minority Advantages, and Frequency-Dependent Natural Selection

Evolution, 1977
Frequency-dependent natural selection is potentially important both as a mode by which gene frequencies of populations change and also as a possible explanation of the genetic load paradox. If most alleles are maintained at equilibrium under a frequency-dependent mode such that they are selectively equivalent at equilibrium, then no load is felt by ...
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Frequency-dependent sexual selection

Philosophical Transactions of the Royal Society of London. B, Biological Sciences, 1988
Abstract Sexual selection by female choice is expected to give rise to a frequency-dependent sexual advantage in favour of preferred male phenotypes: the rarer the preferred phenotypes, the more often they are chosen as mates. This ‘rare-male advantage’ can maintain a polymorphism when two or more phenotypes are mated preferentially ...
P, O'Donald, M E, Majerus
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Frequency dependence of the fixed point in a fluctuating frequency comb

2008 Conference on Lasers and Electro-Optics, 2007
We report measurements of the response of a Kerr-lens mode-locked Ti:sapphire frequency comb to pump power modulation. For each setting of the laser, the comb expands and contracts about a particular fixed point in frequency. We measured this fixed point and found that it is within 8% of our frequency comb's center.
Walker, D., Udem, T., Gohle, C., Stein, B., Hänsch, T.   +4 more
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