Dielectric properties of the hydrogen-bonded ferroelectric crystal KH_(2)PO_(4)(KDP)differ significantly from those of KD_(2)PO_(4)(DKDP).It is well established that deuteration affects the interplay of hydrogenbond s...
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Dielectric properties of the hydrogen-bonded ferroelectric crystal KH_(2)PO_(4)(KDP)differ significantly from those of KD_(2)PO_(4)(DKDP).It is well established that deuteration affects the interplay of hydrogenbond switches and heavy ion displacements that underlie the emergence of macroscopic polarization,but a detailed microscopic model is *** show that all-atompath integral molecular dynamics simulations can predict the isotope effects,revealing the microscopic mechanism that differentiates KDP and *** tunneling generates phosphate configurations that do not contribute to the *** low temperatures,these quantum dipolar defects are substantial in KDP but negligible in *** intrinsic defects explain why KDP has lower spontaneous polarization and transition entropy than *** prominent role of quantum fluctuations in KDP is related to the unusual strength of the hydrogen bonds and should be equally important in other crystals of the KDP family,which exhibit similar isotope effects.
We use density functional methods to identify the atomic configurations of H and D atoms trapped by O impurities embedded in bulk Nb. The O atoms are located at the octahedral position in the Nb body-centered cubic (B...
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We use density functional methods to identify the atomic configurations of H and D atoms trapped by O impurities embedded in bulk Nb. The O atoms are located at the octahedral position in the Nb body-centered cubic (BCC) lattice, and H (D) atoms tunnel between two degenerate tetrahedral sites separated by a mirror plane. Using nudged elastic band (NEB) methods, we calculate the double-well potential for O-H and O-D impurities and the wave functions and tunnel splittings for H and D atoms. Our results agree with those obtained from analysis of heat capacity and neutron scattering measurements on Nb with low concentrations of O-H and O-D.
This work proposed the utilization of dielectric barrier discharge (DBD) plasma to lengthen the shelf life of Namwa bananas. The samples of fresh Namwa bananas were packaged by different technique to carry out the stu...
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Cells respond to chemical signals, and the precision with which they can sense these signals is fundamentally limited by the stochastic nature of diffusion and ligand binding. Berg and Purcell famously investigated ho...
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Cells respond to chemical signals, and the precision with which they can sense these signals is fundamentally limited by the stochastic nature of diffusion and ligand binding. Berg and Purcell famously investigated how well a small sensor in an infinite ligand bath can determine the ligand concentration, and a number of subsequent analyses have refined and built upon their classical estimates. Not all concentration-sensing problems, however, occur in such an infinite geometry. At different scales, subcellular sensors and cells in tissues are both often confronted with signals whose diffusion is affected by confining boundaries. It is thus valuable to understand how basic limits on chemosensation depend on the sensor's size and on its position in the domain in which ligand diffuses. Here we compute how sensor size and proximity to reflecting boundaries affect the diffusion-limited precision of chemosensation for various geometries in one and three dimensions. We derive analytical expressions for the sensing limit in these geometries. Among our conclusions is the surprising result that, in certain circumstances, smaller sensors can be more effective than larger sensors. This effect arises from a trade-off between spatial averaging and time averaging that we analyze in detail. We also find that proximity to confining boundaries can degrade a sensor's precision significantly compared to the precision of the same sensor far from any boundaries.
The reactive oxygen nitrogen species (RONS) from plasma activation is intensively used in agriculture, particularly in the regulation of seeds germination and plants growth. It shows a promising effect on increasing t...
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Ionization produced by low-energy nuclear recoils is among the primary direct signatures of dark matter interactions. Despite the urgency of dark matter detection and the recent measurements of coherent elastic neutri...
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Ionization produced by low-energy nuclear recoils is among the primary direct signatures of dark matter interactions. Despite the urgency of dark matter detection and the recent measurements of coherent elastic neutrino-nucleus scattering, detector response to nuclear recoils is not well characterized in the keVnr and sub−keVnr regime across a variety of materials. We have reperformed a measurement of the ionization produced by monoenergetic 254 eVnr nuclear recoils in Ge with improved digital electronics and additional systematic studies. Our results indicate an ionization yield of 64±8 eVee corresponding to a quenching factor of 25%±3%, greater than the 14% predicted by the Lindhard model. This ionization enhancement could greatly improve the sensitivity of high-purity Ge detectors in dark matter detection and measurement of neutrinos via coherent scattering.
We report that circularly polarized terahertz light pulses can drive chiral phonons, which then induce an effective quasi-static magnetic field on the order of 1 tesla to polarize the paramagnetic cerium fluoride. ...
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Linearly and circularly polarized phonons in monolayer WS2 are directly excited by resonant infrared pulses. The dynamics of coherent and incoherent chiral phonons are measured by time-resolved Raman spectroscopy and ...
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Significant modulation of Poisson's ratio of IV-VI semiconductor monolayers in an electric field was claimed to be discovered by first-principles calculations in The Journal of Physical Chemistry Letters, 2021,12,...
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Significant modulation of Poisson's ratio of IV-VI semiconductor monolayers in an electric field was claimed to be discovered by first-principles calculations in The Journal of Physical Chemistry Letters, 2021,12, 3217-3223. We show that these results are not correct because of improper modeling of the electric field.
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