4,408 research outputs found
1-(4-HydrÂoxy-3,5-dimethoxyÂphenÂyl)ethanone
In the title molÂecule, C10H12O4, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.033 Å). In the crystal, molÂecules are linked into chains along [001] by O—Hâ‹ŻO hydrogen bonds
Quarkyonic matter and quarkyonic stars in an extended RMF model
By combining RMF models and equivparticle models with density-dependent quark
masses, we construct explicitly ``a quark Fermi Sea'' and ``a baryonic Fermi
surface'' to model the quarkyonic phase, where baryons with momentums ranging
from zero to Fermi momentums are included. The properties of nuclear matter,
quark matter, and quarkyonic matter are then investigated in a unified manner,
where quarkyonic matter is more stable and energy minimization is still
applicable to obtain the microscopic properties of dense matter. Three
different covariant density functionals TW99, PKDD, and DD-ME2 are adopted in
our work, where TW99 gives satisfactory predictions for the properties of
nuclear matter both in neutron stars and heavy-ion collisions and quarkyonic
transition is unfavorable. Nevertheless, if PKDD with larger slope of symmetry
energy or DD-ME2 with larger skewness coefficient are adopted, the
corresponding EOSs are too stiff according to both experimental and
astrophysical constraints. The situation is improved if quarkyonic transition
takes place, where the EOSs become softer and can accommodate various
experimental and astrophysical constraints
Delving Deeper into Data Scaling in Masked Image Modeling
Understanding whether self-supervised learning methods can scale with
unlimited data is crucial for training large-scale models. In this work, we
conduct an empirical study on the scaling capability of masked image modeling
(MIM) methods (e.g., MAE) for visual recognition. Unlike most previous works
that depend on the widely-used ImageNet dataset, which is manually curated and
object-centric, we take a step further and propose to investigate this problem
in a more practical setting. Specifically, we utilize the web-collected
Coyo-700M dataset. We randomly sample varying numbers of training images from
the Coyo dataset and construct a series of sub-datasets, containing 0.5M, 1M,
5M, 10M, and 100M images, for pre-training. Our goal is to investigate how the
performance changes on downstream tasks when scaling with different sizes of
data and models. The study reveals that: 1) MIM can be viewed as an effective
method to improve the model capacity when the scale of the training data is
relatively small; 2) Strong reconstruction targets can endow the models with
increased capacities on downstream tasks; 3) MIM pre-training is data-agnostic
under most scenarios, which means that the strategy of sampling pre-training
data is non-critical. We hope these observations could provide valuable
insights for future research on MIM
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