2,626 research outputs found
N′-(2-Furylmethylene)nicotinohydrazide
The asymmetric unit of the title compound, C11H9N3O2, contains two independent molecules: the dihedral angles between the pyridine ring and the furyl ring are 17.00 (16) and 34.12 (15)°. The crystal structure involves intermolecular C—H⋯O, N—H⋯N and N—H⋯O hydrogen bonds
Molecular environment of the thermal composite supernova remnant G352.70.1
Galactic supernova remnants (SNRs) play an important role in our
understanding of supernovae and their feedback on the interstellar environment.
SNR G352.70.1 is special for its thermal composite morphology and
double-ring structure. We have performed spectroscopic mapping in CO and
CO -1 lines toward G352.70.1 with the Atacama Pathfinder
Experiment telescope. Broad CO lines are found in the northeastern ring
at a local-standard-of-rest velocity range of - km s,
suggesting that the remnant is interacting with molecular clouds (MCs) at
km s. Thus, we adopt a distance of kpc for this
SNR. The momentum and kinetic energy of the shocked gas along the line of sight
are estimated to be km s and erg,
respectively. We also find an expanding structure around the remnant, which is
possibly related to the wind-blown bubble of the progenitor star. From the
Fermi-LAT data in an energy range of 0.1-500 GeV, we find no gamma-ray
counterparts of G352.70.1.Comment: 14 pages, 10 figures, accepted for publication in Ap
Deep Learning the Effects of Photon Sensors on the Event Reconstruction Performance in an Antineutrino Detector
We provide a fast approach incorporating the usage of deep learning for
evaluating the effects of photon sensors in an antineutrino detector on the
event reconstruction performance therein. This work is an attempt to harness
the power of deep learning for detector designing and upgrade planning. Using
the Daya Bay detector as a benchmark case and the vertex reconstruction
performance as the objective for the deep neural network, we find that the
photomultiplier tubes (PMTs) have different relative importance to the vertex
reconstruction. More importantly, the vertex position resolutions for the Daya
Bay detector follow approximately a multi-exponential relationship with respect
to the number of PMTs and hence, the coverage. This could also assist in
deciding on the merits of installing additional PMTs for future detector plans.
The approach could easily be used with other objectives in place of vertex
reconstruction
Gray-body factor and absorption of the Dirac field in ESTGB gravity
The gray-body factor and the absorption cross section of the 4D ESTGB gravity
with a mode of nonlinear electrodynamics for the massless Dirac field are
studied in this paper. The magnetic charge value varies between
and as well as the ADM mass is set to , which
corresponds to a non-extreme black hole. The gray-body factor is obtained using
the semi-analytic WKB method after solving the massless Dirac equation. When
the absolute value of magnetic charge is increasing, the gray-body factor
is decreasing. In addition, the partial absorption cross
section and the total absorption cross section are calculated by using the
partial wave method. We find that the maximum value of partial absorption cross
section decreases as increases. And the existence of magnetic charge
causes the diminishing of the total absorption cross section. Finally, we find
that the absorption cross section of the Dirac field is more sensitive to
electric charge than magnetic charge by comparing the absorption cross section
of the Reissner-Nordstrm and ESTGB-NLED black holes.Comment: 11 pages, 7 figure
Preparation and characterization of carboxyl-group functionalized superparamagnetic nanoparticles and t he potential for bio-applications
In this work, a method was developed to prepare monodispersed carboxyl-group functionalized magnetic nanoparticles. Nanosized maghemite (y-Fe2O3, 7.0 ± 1.0 nm) was synthesized using thermal co-precipitation method and subsequently coated with functional groups by one-step suspension copolymerization. The Fourier transform infrared spectroscopy study and thermogravitmetric analyses confirmed the successful functionalization of carboxyl groups on the surface of magnetic nanocrystals. The surface chemistry makes it possible for SPRI (solid phase reversible immobilization)-based DNA purification. Thus the nanoparticles were employed to isolate plasmid DNA from bacterial cell culture and the results demonstrated its applicability in DNA preparation
Performance Analysis and Optimization of Compressed Air Energy Storage Integrated with Latent Thermal Energy Storage
Recovering compression waste heat using latent thermal energy storage (LTES) is a promising method to enhance the round-trip efficiency of compressed air energy storage (CAES) systems. In this study, a systematic thermodynamic model coupled with a concentric diffusion heat transfer model of the cylindrical packed-bed LTES is established for a CAES system, and the numerical simulation model is validated by experimental data in the reference. Based on the numerical model, the charging–discharging performance of LTES and CAES systems is evaluated under different layouts of phase change materials (PCMs) in LTES, and the optimal layout of PCM is specified as a three-stage layout, since the exergy efficiency of LTES and round-trip efficiency are improved by 8.2% and 6.9% compared with a one-stage layout. Then, the proportion of three PCMs is optimized using response surface methods. The optimization results indicate that the exergy efficiency of LTES and round-trip efficiency of the CAES system are expected to be 80.9% and 73.3% under the PCM proportion of 0.48:0.3:0.22 for three stages, which are 7.0% and 13.1% higher than the original three-stage PCMs with equal proportions
- …