2,679 research outputs found
Different critical points of chiral and deconfinement phase transitions in (2+1)-dimensional fermion-gauge interacting model
Based on the truncated Dyson-Schwinger equations for fermion and massive
boson propagators in QED, the fermion chiral condensate and the mass
singularities of the fermion propagator via the Schwinger function are
investigated. It is shown that the critical point of chiral phase transition is
apparently different from that of deconfinement phase transition and in Nambu
phase the fermion is confined only for small gauge boson mass.Comment: 5 Pages and 3 figure
The Schur concavity, Schur multiplicative and harmonic convexities of the second dual form of the Hamy symmetric function with applications
AbstractFor x=(x1,x2,…,xn)∈R+n, the second dual form of the Hamy symmetric function is defined by Hn∗∗(x,r)=Hn∗∗(x1,x2,…,xn;r)=∏1≤i1<i2<⋯<ir≤n(∑j=1rxij)1r, where r∈{1,2,…,n} and i1,i2,…,in are positive integers.In this paper, we prove that Hn∗∗(x,r) is Schur concave, and Schur multiplicatively and harmonic convex in R+n. Some applications in inequalities and reliability theory are presented
A routing protocol for multisink wireless sensor networks in underground coalmine tunnels
Traditional underground coalmine monitoring systems are mainly based on the use of wired transmission. However, when cables are damaged during an accident, it is difficult to obtain relevant data on environmental parameters and the emergency situation underground. To address this problem, the use of wireless sensor networks (WSNs) has been proposed. However, the shape of coalmine tunnels is not conducive to the deployment of WSNs as they are long and narrow. Therefore, issues with the network arise, such as extremely large energy consumption, very weak connectivity, long time delays, and a short lifetime. To solve these problems, in this study, a new routing protocol algorithm for multisink WSNs based on transmission power control is proposed. First, a transmission power control algorithm is used to negotiate the optimal communication radius and transmission power of each sink. Second, the non-uniform clustering idea is adopted to optimize the cluster head selection. Simulation results are subsequently compared to the Centroid of the Nodes in a Partition (CNP) strategy and show that the new algorithm delivers a good performance: Power efficiency is increased by approximately 70%, connectivity is increased by approximately 15%, the cluster interference is diminished by approximately 50%, the network lifetime is increased by approximately 6%, and the delay is reduced with an increase in the number of sinks
Quasi-periodic Variations of Coronal Mass Ejections with Different Angular Widths
Coronal mass ejections (CMEs) are energetic expulsions of organized magnetic
features from the Sun. The study of CME quasi-periodicity helps establish a
possible relationship between CMEs, solar flares, and geomagnetic disturbances.
We used the angular width of CMEs as a criterion for classifying the CMEs in
the study. Based on 25 years of observational data, we systematically analyzed
the quasi-periodic variations corresponding to the CME occurrence rate of
different angular widths in the northern and southern hemispheres, using
frequency and time-frequency analysis methods. There are various periods for
CMEs of different angular widths: 9 months, 1.7 years, and 3.3-4.3 years.
Compared with previous studies based on the occurrence rate of CMEs, we
obtained the same periods of 1.2(+-0.01) months, 3.1(+-0.04) months,
~6.1(+-0.4) months, 1.2(+-0.1) years, and 2.4(+-0.4) years. We also found
additional periods of all CMEs that appear only in one hemisphere or during a
specific solar cycle. For example, 7.1(+-0.2) months and 4.1(+-0.2) years in
the northern hemisphere, 1(+-0.004) months, 5.9(+-0.2) months, 1(+-0.1) years,
1.4(+-0.1) years, and 2.4(+-0.4) years in the southern hemisphere, 6.1(+-0.4)
months in solar cycle 23 (SC23) and 6.1(+-0.4) months, 1.2(+-0.1) years, and
3.7(+-0.2) years in solar cycle 24 (SC24). The analysis shows that
quasi-periodic variations of the CMEs are a link among oscillations in coronal
magnetic activity, solar flare eruptions, and interplanetary space.Comment: 18 pages, 8 figures, 4 tables, Accepted by AP
(E)-N′-(3,4-Dichlorobenzylidene)nicotinohydrazide monohydrate
In the title compound, C13H9Cl2N3O·H2O, the 3,4-dichlorobenzene ring is nearly coplanar with the pyridine ring, making a dihedral angle of 4.78 (8)°. Intermolecular O—H⋯O, O—H⋯N, N—H⋯O and weak C—H⋯O hydrogen bonding is present in the crystal structure
A new species of cosmocerca (Nematoda, ascaridomorpha) from the marine toad rhinella marina (linnaeus) (anura, bufonidae) in Australia
The marine toad Rhinella marina (Linnaeus) (Anura, Bufonidae) is a notorious, exotic amphibian species in Australia. However, our present knowledge of the composition of the nematode fauna of R. marina is still not complete. In the present study, a new cosmocercid nematode, Cosmocerca multipapillata sp. nov., was described using both light and scanning electron microscopy, based on specimens collected from R. marina in Australia. Cosmocerca multipapillata sp. nov. can be easily distinguished from its congeners by the body size, the presence of lateral alae and well sclerotized gubernaculum, the number and arrangement of plectanes and rosettes and the length of spicules, oesophagus and tail
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