751 research outputs found
Ballistic Thermal Rectification in Asymmetric Three-Terminal Mesoscopic Dielectric Systems
By coupling the asymmetric three-terminal mesoscopic dielectric system with a
temperature probe, at low temperature, the ballistic heat flux flow through the
other two asymmetric terminals in the nonlinear response regime is studied
based on the Landauer formulation of transport theory. The thermal
rectification is attained at the quantum regime. It is a purely quantum effect
and is determined by the dependence of the ratio
on , the phonon's frequency.
Where and are respectively the
transmission coefficients from two asymmetric terminals to the temperature
probe, which are determined by the inelastic scattering of ballistic phonons in
the temperature probe. Our results are confirmed by extensive numerical
simulations.Comment: 10 pages, 4 figure
Prospects for Constraining interacting dark energy cosmology with gravitational-wave bright sirens detected by future SKA-era pulsar timing arrays
Pulsar timing arrays (PTAs) have the potential to detect Nanohertz
gravitational waves (GWs) that are usually generated by the individual
inspiraling supermassive black hole binaries (SMBHBs) in the galactic centers.
The GW signals as cosmological standard sirens can provide the absolute cosmic
distances, thereby can be used to constrain the cosmological parameters. In
this paper, we analyze the ability of future SKA-era PTAs to detect the
existing SMBHBs candidates assuming the root mean square of timing noise
, and use the simulated PTA data to constrain the
interacting dark energy (IDE) models with energy transfer rate . We find that, the future SKA-era PTAs will play an important role in
constraining the IDE cosmology. Using only the mock PTA data consisting of 100
pulsars, we obtain
and in the ICDM model, which are much better
than the results from the Planck TT, TE, EE+lowE. However, the PTA data cannot
provide a tight constraint on the coupling parameter compared with
Planck, but the data combination of Planck+PTA can provide a rather tight
constraint, i.e., , since the PTA data could break the
parameter degeneracies inherent in CMB. In the ICDM model, we obtain
and from the Planck+PTA data
combination. In addition, we also find that with the increase of the number of
pulsars in PTA, the constraint results from the Planck+PTA will be further
improved to some extent. We show that the observations of Nanohertz GWs with
future SKA-era PTAs will provide a powerful tool for exploring the nature of
dark energy and measuring the coupling between dark energy and dark matter
FocusFlow: Boosting Key-Points Optical Flow Estimation for Autonomous Driving
Key-point-based scene understanding is fundamental for autonomous driving
applications. At the same time, optical flow plays an important role in many
vision tasks. However, due to the implicit bias of equal attention on all
points, classic data-driven optical flow estimation methods yield less
satisfactory performance on key points, limiting their implementations in
key-point-critical safety-relevant scenarios. To address these issues, we
introduce a points-based modeling method that requires the model to learn
key-point-related priors explicitly. Based on the modeling method, we present
FocusFlow, a framework consisting of 1) a mix loss function combined with a
classic photometric loss function and our proposed Conditional Point Control
Loss (CPCL) function for diverse point-wise supervision; 2) a conditioned
controlling model which substitutes the conventional feature encoder by our
proposed Condition Control Encoder (CCE). CCE incorporates a Frame Feature
Encoder (FFE) that extracts features from frames, a Condition Feature Encoder
(CFE) that learns to control the feature extraction behavior of FFE from input
masks containing information of key points, and fusion modules that transfer
the controlling information between FFE and CFE. Our FocusFlow framework shows
outstanding performance with up to +44.5% precision improvement on various key
points such as ORB, SIFT, and even learning-based SiLK, along with exceptional
scalability for most existing data-driven optical flow methods like PWC-Net,
RAFT, and FlowFormer. Notably, FocusFlow yields competitive or superior
performances rivaling the original models on the whole frame. The source code
will be available at https://github.com/ZhonghuaYi/FocusFlow_official.Comment: The source code of FocusFlow will be available at
https://github.com/ZhonghuaYi/FocusFlow_officia
Full-length enriched multistage cDNA library construction covering floral bud development in Populus tomentosa
Flowering involves expression of a suite of genes associated with floral development. The genome of the Chinese white poplar (Populus trichocarpa) was sequenced because of its importance as a model tree for genetic studies as well as being an economically important woody plant. However, information on expressed genes involved in poplar floral bud development is insufficient to allow annotation of genes and use of the genomic information. To isolate and characterize genes involved in flowering of Populus tomentosa, floral bud samples were collected at different developmental stages from floral bud initiation to flower maturity, and full-length enriched cDNA libraries from both male and female floral buds were constructed. The results of titer analysis showed that the titer of the female and male primary libraries were 8.00 × 105 and 7.20 × 105 pfu/ml, respectively, and the titer of the amplified libraries were 2.60 × 108 and 2.56 × 108 pfu/ml, respectively. The combination ratio reached 90% and the insert size was 400 to 2000 bp. The results indicated that cDNA libraries were successfully constructed.Keywords: cDNA library, floral bud, flowering, Populus tomentosaAfrican Journal of Biotechnology Vol. 11(29), pp. 7373-7377, 10 April, 201
(2E,6E)-2,6-Difurfurylidenecyclohexanone
The complete molecule of the title compound, C16H14O3, is generated by crystallographic mirror symmetry, with two C atoms and one O atom lying on the mirror plane. The molecule adopts an E configuration about the C=C bond and the dihedral angle between the furan rings is 16.1 (2)°
- …