857 research outputs found
Phenomenological discriminations of the Yukawa interactions in two-Higgs doublet models with symmetry
There are four types of two-Higgs doublet models under a discrete
symmetry imposed to avoid tree-level flavour-changing neutral current, i.e.
type-I, type-II, type-X and type-Y models. We investigate the possibility to
discriminate the four models in the light of the flavour physics data,
including mixing, , and
decays, the recent LHC Higgs data, the direct search
for charged Higgs at LEP, and the constraints from perturbative unitarity and
vacuum stability. After deriving the combined constraints on the Yukawa
interaction parameters, we have shown that the correlation between the mass
eigenstate rate asymmetry of and the
ratio could be sensitive probe to discriminate the four models with
future precise measurements of the observables in the
decay at LHCb.Comment: 29 pages, 4 tables, 11 figures. v3: minor corrections included,
matches published version in EPJ
Multiple scattering effects on heavy meson production in p+A collisions at backward rapidity
We study the incoherent multiple scattering effects on heavy meson production
in the backward rapidity region of p+A collisions within the generalized
high-twist factorization formalism. We calculate explicitly the double
scattering contributions to the heavy meson differential cross sections by
taking into account both initial-state and final-state interactions, and find
that these corrections are positive. We further evaluate the nuclear
modification factor for muons that come form the semi-leptonic decays of heavy
flavor mesons. Phenomenological applications in d+Au collisions at a
center-of-mass energy GeV at RHIC and in p+Pb collisions at
TeV at the LHC are presented. We find that incoherent multiple
scattering can describe rather well the observed nuclear enhancement in the
intermediate region for such reactions.Comment: 10 pages, 6 figures, published version in PL
MuLTI: Efficient Video-and-Language Understanding with MultiWay-Sampler and Multiple Choice Modeling
Video-and-language understanding has a variety of applications in the
industry, such as video question answering, text-video retrieval and
multi-label classification. Existing video-and-language understanding methods
generally adopt heavy multi-modal encoders and feature fusion modules, which
consume large amounts of GPU memory. Especially, they have difficulty dealing
with dense video frames or long text that are prevalent in industrial
applications. In this paper, we propose MuLTI, a highly accurate and
memory-efficient video-and-language understanding model that achieves efficient
and effective feature fusion through feature sampling and attention modules.
Therefore, MuLTI can handle longer sequences with limited GPU memory. Then, we
introduce an attention-based adapter to the encoders, which finetunes the
shallow features to improve the model's performance with low GPU memory
consumption. Finally, to further improve the model's performance, we introduce
a new pretraining task named Multiple Choice Modeling to bridge the task gap
between pretraining and downstream tasks and enhance the model's ability to
align the video and the text. Benefiting from the efficient feature fusion
module, the attention-based adapter and the new pretraining task, MuLTI
achieves state-of-the-art performance on multiple datasets. Implementation and
pretrained models will be released
Effects of low temperature and drought on the physiological and growth changes in oil palm seedlings
Water deficiency and low temperature are two important ecological factors which affect the distribution and cultivation of oil palm. To find out how oil palm adapts to the environmental conditions, the dynamics of a series of important physiological components derived from the leaves of potted oil palm seedlings under drought stress (DS) (water with holding) and low temperature stress (LTS) (10°C) were studied. The results showed that low temperature and water stress inhibited the growth of oil palm seedlings. The relative conductivity, injury index, malondialdehyde (MDA) and proline content in the leaves increased to different degrees with the extension of low temperature and drought stress. Superoxide dismutase (SOD) and peroxidase (POD) activities increased and then decreased gradually with the duration of treatment time. The variations of the earlier mentioned parameters except proline content under low temperature stress were greater than that under drought stress. Thus, oil palm possibly showed different response mechanisms under low temperature and drought stress by mediations of these substances, in order to increase plant defense capability. These data provided the information that was utilized to initiate the breeding programme used to improve drought and cold tolerance in oil palm.Keywords: Oil palm, drought stress, low temperature stress, physiological characteristic
catena-Poly[[triaqua(pyridine-κN)nickel(II)]-μ-sulfato-κ2 O:O′]
The title compound, [Ni(SO4)(C5H5N)(H2O)3]n, was synthesized by the hydrothermal reaction of NiSO4·6H2O, pyridine and water. The central NiII atom is coordinated in a distorted octahedral environment by a pyridine N atom, three aqua O atoms and two O atoms of bridging sulfate anions, yielding a zigzag chain. A three-dimensional network is generated via complex hydrogen bonds involving the sulfate and aqua ligands and a pyridine C—H group
2′,10′-Dibromospiro[cylohexane-1,6-dibenzo[d,f][1,3]dioxepine]
In the title compound, C18H16Br2O2, the dihedral angle between the aromatic rings is 35.55 (17)° and the cyclohexyl ring adopts a chair-like conformation. In the crystal, molecules are linked by van der Waals forces
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