341 research outputs found
Engineering Ratchet-Based Particle Separation via Shortcuts to Isothermality
Microscopic particle separation plays vital role in various scientific and
industrial domains. In this Letter, we propose a universal non-equilibrium
thermodynamic approach, employing the concept of Shortcuts to Isothermality, to
realize controllable separation of overdamped Brownian particles. By utilizing
a designed ratchet potential with temporal period , we find in the
slow-driving regime that the average particle velocity
\Bar{v}_s\propto\left(1-D/D^*\right)\tau^{-1}, indicating that particles with
different diffusion coefficients can be guided to move in distinct
directions with a preset . Furthermore, we reveal that there exists an
extra energetic cost with a lower bound
W_{\rm{ex}}^{(\rm{min})}\propto\mathcal{L}^{2}\Bar{v}_s, alongside a
quasi-static work consumption. Here, is the thermodynamic length
of the driving loop in the parametric space. We numerically validate our
theoretical findings and illustrate the optimal separation protocol (associated
with ) with a sawtooth potential. This study
establishes a bridge between thermodynamic process engineering and particle
separation, paving the way for further explorations of thermodynamic constrains
and optimal control in ratchet-based particle separation.Comment: 5 pages, 3 figures + Supplemental Materials (10 pages, 4 figures).
Comments are welcome
2,2′-[(4,6-Dinitro-1,3-phenylene)dioxy]diacetic acid hemihydrate
The skeletons of both independent molecules of the carboxylic acid hemihydrate, C10H8N2O10·0.5H2O, are approximately planar [maximum deviations 0.642 (3) and 0.468 (1) Å]. The deviations arise from the twisting of the nitro groups with respect to the aromatic rings [dihedral angles = 3.24 (2) and 27.01 (1), and 7.87 (1) and 16.37 (2)° in the two molecules]. The crystal structure features intermolecular O—H⋯O hydrogen bonds, which the link the dicarboxylic acid and water molecules into a supramolecular layer network
Hyperon polarization in e^-p --> e^-HK with polarized electron beams
We apply the picture proposed in a recent Letter for transverse hyperon
polarization in unpolarized hadron-hadron collisions to the exclusive process
e^-p --> e^-HK such as e^-p-->e^-\Lambda K^+, e^-p --> e^-\Sigma^+ K^0, or
e^-p--> e^-\Sigma^0 K^+, or the similar process e^-p\to e^-n\pi^+ with
longitudinally polarized electron beams. We present the predictions for the
longitudinal polarizations of the hyperons or neutron in these reactions, which
can be used as further tests of the picture.Comment: 15 pages, 2 figures. submitted to Phys. Rev.
Hyperon polarization in semi-inclusive deeply inelastic lepton-nucleon scattering at high energy
We calculate the polarizations for different octet hyperons produced in the
current fragmentation regions of the deeply inelastic lepton-nucleon
scatterings and at high energy
using different models for spin transfer in fragmentation processes. The
results show that measurements of those hyperon polarizations should provide
useful information to distinguish between different models in particular the
SU(6) and the DIS pictures used frequently in the literature. We found, in
particular, that measuring the polarization of produced in these
processes can give a better test to the validity of the different spin transfer
models.Comment: 30 pages, 13 figure
Probing gluon helicity distribution and quark transversity through hyperon polarization in singly polarized pp collisions
We study the polarization of hyperon in different processes in singly
polarized collisions, in particular its relation to the polarized parton
distributions. We show that by measuring hyperon polarization in particularly
chosen processes, one can extract useful information on these parton
distributions. We show in particular that, by measuring the
polarization in high direct photon production process, one can extract
information on the gluon helicity distribution; and by measuring the transverse
polarization of hyeprons with high in singly polarized reactions, one can
obtain useful information on the transversity distribution. We present the
numerical results obtained for those hyperon polarizations using different
models for parton distribution function and those for the spin transfer in
fragmentation processes.Comment: 25 pages, 8 figures, to appear in Phys. Rev.
N-(3,4-Diethoxyphenyl)acetamide
In the title compound, C12H17NO3, the conformations of the N—H and C=O bonds are anti to each other. In the crystal structure, N—H⋯O hydrogen-bond interactions help to establish the packing
Spin alignments of vector mesons in deeply inelastic lepton-nucleon scattering
We extend the calculations of the spin alignments of vector mesons in
annihilation in a recent Rapid Communication to deeply inelastic
lepton-nucleon scatterings. We present the results for different mesons in the
current fragmentation regions of at high energies
and at both high and low energies. We also present
the predictions for at NOMAD energies in the
target fragmentation region using a valence quark model.Comment: 4 pages, 6 figures; to appear in Phys. Rev.
Spin alignment of vector meson in e+e- annihilation at Z0 pole
We calculate the spin density matrix of the vector meson produced in e+e-
annihilation at Z^0 pole. We show that the data imply a significant
polarization for the antiquark which is created in the fragmentation process of
the polarized initial quark and combines with the fragmenting quark to form the
vector meson. The direction of polarization is opposite to that of the
fragmenting quark and the magnitude is of the order of 0.5. A qualitative
explanation of this result based on the LUND string fragmentation model is
given.Comment: 15 pages, 2 fgiures; submitted to Phys. Rev.
Time-Specific Ecologic Niche Models Forecast the Risk of Hemorrhagic Fever with Renal Syndrome in Dongting Lake District, China, 2005–2010
Background: Hemorrhagic fever with renal syndrome (HFRS), a rodent-borne infectious disease, is one of the most serious public health threats in China. Increasing our understanding of the spatial and temporal patterns of HFRS infections could guide local prevention and control strategies.
Methodology/Principal Findings: We employed statistical models to analyze HFRS case data together with environmental data from the Dongting Lake district during 2005–2010. Specifically, time-specific ecologic niche models (ENMs) were used to quantify and identify risk factors associated with HFRS transmission as well as forecast seasonal variation in risk across geographic areas.
Results showed that the Maximum Entropy model provided the best predictive ability (AUC = 0.755). Time-specific Maximum Entropy models showed that the potential risk areas of HFRS significantly varied across seasons. High-risk areas were mainly found in the southeastern and southwestern areas of the Dongting Lake district. Our findings based on models focused on the spring and winter seasons showed particularly good performance. The potential risk areas were smaller in March, May and August compared with those identified for June, July and October to December. Both normalized difference vegetation index (NDVI) and land use types were found to be the dominant risk factors.
Conclusions/Significance: Our findings indicate that time-specific ENMs provide a useful tool to forecast the spatial and temporal risk of HFRS
Spatial and temporal clustering analysis of tuberculosis in the mainland of China at the prefecture level, 2005-2015
BACKGROUND: Tuberculosis (TB) is still one of the most serious infectious diseases in the mainland of China. So it was urgent for the formulation of more effective measures to prevent and control it.
METHODS: The data of reported TB cases in 340 prefectures from the mainland of China were extracted from the China Information System for Disease Control and Prevention (CISDCP) during January 2005 to December 2015. The Kulldorff\u27s retrospective space-time scan statistics was used to identify the temporal, spatial and spatio-temporal clusters of reported TB in the mainland of China by using the discrete Poisson probability model. Spatio-temporal clusters of sputum smear-positive (SS+) reported TB and sputum smear-negative (SS-) reported TB were also detected at the prefecture level.
RESULTS: A total of 10 200 528 reported TB cases were collected from 2005 to 2015 in 340 prefectures, including 5 283 983 SS- TB cases and 4 631 734 SS + TB cases with specific sputum smear results, 284 811 cases without sputum smear test. Significantly TB clustering patterns in spatial, temporal and spatio-temporal were observed in this research. Results of the Kulldorff\u27s scan found twelve significant space-time clusters of reported TB. The most likely spatio-temporal cluster (RR = 3.27, P \u3c 0.001) was mainly located in Xinjiang Uygur Autonomous Region of western China, covering five prefectures and clustering in the time frame from September 2012 to November 2015. The spatio-temporal clustering results of SS+ TB and SS- TB also showed the most likely clusters distributed in the western China. However, the clustering time of SS+ TB was concentrated before 2010 while SS- TB was mainly concentrated after 2010.
CONCLUSIONS: This study identified the time and region of TB, SS+ TB and SS- TB clustered easily in 340 prefectures in the mainland of China, which is helpful in prioritizing resource assignment in high-risk periods and high-risk areas, and to formulate powerful strategy to prevention and control TB
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