12,291 research outputs found
Black hole thermodynamics and modified GUP consistent with doubly special relativity
We study the black hole thermodynamics and obtain the correction terms for
temperature, entropy, and heat capacity of the Schwarzschild black hole,
resulting from the commutation relations in the framework of {\it Modified
Generalized Uncertainty Principle} suggested by {\it Doubly Special
Relativity}.Comment: 13 pages, 6 figures, minor revision, references adde
Optical and magnetic properties of Ni nanoparticles in rutile formed by Ni ion implantation
Crystalline Ni nanoparticles in the near surface of TiO2TiO2 (rutile) have been synthesized by Ni ion beam implantation at room temperature to a fluence of 1×1017/cm21×1017∕cm2. Transmission electron microscopy, optical absorption spectroscopy, and a superconducting quantum interference device magnetometer have been utilized to characterize the nanostructure, optical and magnetic properties of Ni particles in TiO2TiO2. Crystalline Ni nanoparticles with dimensions ranging 3–20 nm formed in the near surface of rutile, which caused a broad absorption band from 700 nm in the optical absorption spectrum. Magnetic measurement indicated that the coercive force of Ni nanoparticles was about 210 Oe at 10 K. The superparamagnetism of the nanoparticles was observed above blocking temperature T = 85 KT=85K.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87774/2/043107_1.pd
Metamagnetic Transition in NaCoO Single Crystals
We report the magnetization, specific heat and transport measurements of high
quality NaCoO single crystals in applied magnetic fields up to
14T. In high temperatures, the system is in a paramagnetic phase. It undergoes
a magnetic phase transition below about 20K. When the field is applied along
the c-axis, the measurement data of magnetization, specific heat and
magnetoresistance reveal a metamagnetic transition from an antiferromagnetic
state to a quasi-ferromagnetic state at about 8T in low temperatures. However,
no transition is observed in the magnetization measurements up to 14T when the
field is applied perpendicular to the c-axis. The low temperature magnetic
phase diagram of NaCoO is determined.Comment: 4 pages, 5 figure
The Fano resonance for Anderson impurity systems
We present a general theory for the Fano resonance in Anderson impurity
systems. It is shown that the broadening of the impurity level leads to an
additional and important contribution to the Fano resonance around the Fermi
surface, especially in the mixed valence regime. This contribution results from
the interference between the Kondo resonance and the broadened impurity level.
Being applied to the scanning tunnelling microscopic experiments, we find that
our theory gives a consistent and quantitative account for the Fano resonance
lineshapes for both Co and Ti impurities on Au or Ag surfaces. The Ti systems
are found to be in the mixed valence regime.Comment: 4 pages, 5 figures, published versio
Sound propagation in density wave conductors and the effect of long-range Coulomb interaction
We study theoretically the sound propagation in charge- and spin-density
waves in the hydrodynamic regime. First, making use of the method of comoving
frame, we construct the stress tensor appropriate for quasi-one dimensional
systems within tight-binding approximation. Taking into account the screening
effect of the long-range Coulomb interaction, we find that the increase of the
sound velocity below the critical temperature is about two orders of magnitude
less for longitudinal sound than for transverse one. It is shown that only the
transverse sound wave with displacement vector parallel to the chain direction
couples to the phason of the density wave, therefore we expect significant
electromechanical effect only in this case.Comment: revtex, 14 pages (in preprint form), submitted to PR
Study on the extraction of dioscin by the ultrasonicassisted ethanol
With Dioscorea zingiberensis as row materials, and with the yield of diosgenin as assessment criteria, the effect on extraction yield of dioscin of frequency of ultrasonic, the period of ultrasonic and solidliquid ratio (D. zingiberensis : alcohol) was studied via orthogonal test. A new and unique method to accomplish this was by utilizing the technology of ultrasonic assisted ethanol extraction. The optimal processing parameters of this method were confirmed. The method was compared with solvent extraction process for the effect on extraction yield of dioscin. It was shown that the technology of ultrasonic assisted ethanol extraction which can significantly increase the extraction yield and extraction efficiency of dioscin. The ultrasonic did not destroy D. zingiberensis cell structure, but decreased the boundary layer thickness between D. zingiberensis (solid phase) and alcohol (medium), and accelerated cells inside and outside the material exchange. International rectifier (IR) further demonstrated that ultrasonic merely increased extraction yield of dioscin instead of destroying the cell structure.Keywords: D. zingiberensis, ultrasonic waves, extraction, diosgenin
On exploiting priority relation graph for reliable multi-path communication in mobile social networks
© 2018 Elsevier Inc. A mobile social network (MSN) consists of certain amount of mobile users with social characteristics, and it provides data delivery concerning social relationships between mobile users. In MSN, ordinary people contact each other more frequently if they have more social features in common. In this paper, we apply a new topology structure–priority relation graph (PRG) to evaluate the data delivery routing in MSN on the system-level. By using the natural order of nodes’ representation, the diameter, the regular degree and the multi-path technology, we determine the priority relation graph-based social feature routing (PRG-SFR) algorithm to find disjointed multi-paths in MSN. Here, the multi-path technology can be exploited for ensuring that, between each pair of sender and receiver, the important information can be delivered through a highly reliable path. Then we calculate the tolerant ability of ‘faults’ and estimate the availability of MSN on the theoretical level. Finally, we analyze the efficiency of PRG-SFR algorithm from the numerical standpoint in terms of fault tolerance, forwarding number, transmission time and delivery rate. Moreover, we make comparisons between PRG-SFR algorithm and certain state-of-the-art technologies
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