813 research outputs found
How to interpret a discovery or null result of the decay
The Majorana nature of massive neutrinos will be crucially probed in the
next-generation experiments of the neutrinoless double-beta ()
decay. The effective mass term of this process, , may
be contaminated by new physics. So how to interpret a discovery or null result
of the decay in the foreseeable future is highly nontrivial. In
this paper we introduce a novel three-dimensional description of , which allows us to see its sensitivity to the lightest
neutrino mass and two Majorana phases in a transparent way. We take a look at
to what extent the free parameters of can be well
constrained provided a signal of the decay is observed someday.
To fully explore lepton number violation, all the six effective Majorana mass
terms (for )
are calculated and their lower bounds are illustrated with the two-dimensional
contour figures. The effect of possible new physics on the decay
is also discussed in a model-independent way. We find that the result of
in the normal (or inverted) neutrino mass ordering
case modified by the new physics effect may somewhat mimic that in the inverted
(or normal) mass ordering case in the standard three-flavor scheme. Hence a
proper interpretation of a discovery or null result of the decay
may demand extra information from some other measurements.Comment: 13 pages, 6 figures, Figures and references update
Signaling Molecule Hydrogen Sulfide Improves Seed Germination and Seedling Growth of Maize (Zea mays L.) Under High Temperature by Inducing Antioxidant System and Osmolyte Biosynthesis
Hydrogen sulfide (H2S) is a novel type signaling molecule in plants. Seed germination is a key stage of life cycle of plants, which is vulnerable to environmental stress including high temperature. However, under high temperature stress, whether pre-soaking of maize seeds with NaHS (a H2S donor) could improve seed germination and seedling growth and the possible mechanisms are not completely clear. In this study, maize seeds pre-soaked with NaHS enhanced germination percentage, sprout length, root length, and fresh weight compared with the control without NaHS treatment, illustrating that H2S could improve maize seed germination and seedling growth under high temperature. In addition, in comparison to the control, NaHS pre-soaking stimulated antioxidant enzymes [ascorbate peroxidase (APX), glutathione reductase (GR), guaiacol peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT)] activities and the contents of water soluble non-enzymatic antioxidants [ascorbic acid (AsA) and glutathione (GSH)], as well as the ratio of reduced antioxidant to oxidized antioxidant. Moreover, pre-soaking with NaHS activated Δ1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase [OAT; both are rate-limiting enzymes in proline (Pro) synthesis], betaine aldehyde dehydrogenase [BADH; a key enzyme in glycine betaine (GB)], and trehalose (Tre)-6-phosphate phosphatase (a key step in Tre synthesis), which in turn accumulated Pro, GB, and Tre in germinating seeds compared with the control. Also, an improved germination by NaHS under high temperature was reinforced by the above osmotic adjustment substances (osmolytes) alone, while deteriorated by the inhibitors of osmolyte biosynthesis [gabaculine (GAB), disulfiram (DSF), and sodium citrate (SC)]. These results imply that H2S could improve maize seed germination and seedling growth under high temperature by inducing antioxidant system and osmolyte biosynthesis
High platelet reactivity affects the clinical outcomes of patients undergoing percutaneous coronary intervention
Receiver-operating characteristic curve predicting stent thrombosis. (TIFF 5134Â kb
CD39+ Regulatory T cells suppress generation and differentiation of Th17 cells in human malignant pleural effusion via a LAP-dependent mechanism
Enhanced Electromagnetic Transition Dipole Moments and Radiative Decays of Massive Neutrinos due to the Seesaw-induced Non-unitary Effects
In a simple extension of the standard electroweak theory where the phenomenon
of lepton flavor mixing is described by a 3x3 unitary matrix V, the electric
and magnetic dipole moments of three active neutrinos are suppressed not only
by their tiny masses but also by the Glashow-Iliopoulos-Maiani (GIM) mechanism.
We show that it is possible to lift the GIM suppression if the canonical seesaw
mechanism of neutrino mass generation, which allows V to be slightly
non-unitary, is taken into account. In view of current experimental constraints
on the non-unitarity of V, we find that the effective electromagnetic
transition dipole moments of three light Majorana neutrinos and the rates of
their radiative decays can be maximally enhanced by a factor of O(10^2) and a
factor of O(10^4), respectively. This important observation reveals an
intrinsic and presumably significant correlation between the electromagnetic
properties of massive neutrinos and the origin of their small masses.Comment: 10 pages, 4 figures, more discussions and references added, accepted
for publication in PL
The influence of rotating magnetic field on the welding arc motion status
A device generating rotating magnetic field is designed on the bas is of the mechanism of a rotating magnetic field. A rotating magnetic field and electric arc jointing together simulation is studied in this paper to elaborate arc characteristics and behavior under the action of a rotating magnetic field. The rotation radius of the arc are inversely proportional to the rotational frequency of the magnetic field. It is proportional to the field current. Due to constraint function of its own magnetic field of underwater wet welding arc. The influence on the underwater welding arc is smaller than the air welding arc while the magnetic field rotation frequency and magnetic field intensity is changed
TMRT observations of 26 pulsars at 8.6 GHz
Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio
Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities
and pulse width parameters of these pulsars are estimated. For eleven pulsars
these are the first high-frequency observations and for a further four, our
observations have a better signal-to-noise ratio than previous observations.
For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed
profiles. A comparison of 19 profiles with those at other frequencies shows
that in nine cases the separation between the outmost leading and trailing
components decreases with frequency, roughly in agreement with
radius-to-frequency mapping, whereas in the other ten the separation is nearly
constant. Different spectral indices of profile components lead to the
variation of integrated pulse profile shapes with frequency. In seven pulsars
with multi-component profiles, the spectral indices of the central components
are steeper than those of the outer components. For the 12 pulsars with
multi-component profiles in the high-frequency sample, we estimate the core
width using gaussian fitting and discuss the width-period relationship.Comment: 33 pages, 49 figures, 5 Tables; accepted by Ap
Lithium Fiber Growth on the Anode in a Nanowire Lithium Ion Battery During Charging
Lithium (Li) dendrite formation has been recognized as one of the major safety concerns for Li metal batteries but not for conventional Li ion batteries (LIBs) where Li metal is not used. With the advanced in situ transmission electron microscopy enabling direct observation of battery operation, we found that Li fibers with length up to 35 µm grew on nanowire tip after charging. The Li fibers growth were highly directional, i.e., nucleating from the nanowire tip, and extending along the nanowire axis, which was attributed to the strong electric field enhancement effect induced by the sharp nanowire tip. This study reveals a potential safety concern of short-circuit failure for LIBs using nanowire anodes
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