3,570 research outputs found
探討不同科學認識觀的八年級學生在社會性科學議題上論證能力的表現
[[abstract]]This study aimed to explore the development of eighth graders’ argumentation skills and scientific epistemological views through socioscientific issues-based instruction, and the relationship between their argumentation skills and scientific epistemological views. After selecting 42 participators from a remote middle school using convenience sampling, we used the one-group and pre-posttest experimental design to examine the effect of socioscientific issues-based instruction. The results showed that students’ generating arguments, counterarguments, backings, evidences, and qualifiers were not improved significantly after the instruction. Moreover, their scientific epistemological views in the theory-laden exploration of science had changed significantly and were closer to the view of logical positivism. Furthermore, we found that there was a significant difference in argumentation skills between students with different scientific epistemological views, especially in generating backings. Students whose scientific epistemological views tended to constructivism epistemological views would have better argumentation skills after the socioscientific issues-based instruction.
Synthesis of thioesters through copper-catalyzed coupling of aldehydeswith thiols in water
Copper-catalyzed C–S bond formation between aldehydes and thiols in the presence of TBHP as an oxidant is described. Functional groups including chloro, trifluoromethyl, bromo, iodo, nitrile, ester and thiophene are all tolerated by the reaction conditions employed. This reaction is performed in water without the use of a surfactant. Both aryl and alkyl aldehydes couple suitably with aryl- and alkyl thiols, affording the corresponding thioesters in moderate to good yields
Exposing the Functionalities of Neurons for Gated Recurrent Unit Based Sequence-to-Sequence Model
The goal of this paper is to report certain scientific discoveries about a
Seq2Seq model. It is known that analyzing the behavior of RNN-based models at
the neuron level is considered a more challenging task than analyzing a DNN or
CNN models due to their recursive mechanism in nature. This paper aims to
provide neuron-level analysis to explain why a vanilla GRU-based Seq2Seq model
without attention can achieve token-positioning. We found four different types
of neurons: storing, counting, triggering, and outputting and further uncover
the mechanism for these neurons to work together in order to produce the right
token in the right position.Comment: 9 pages (excluding reference), 10 figure
Progressive Transformation Learning for Leveraging Virtual Images in Training
To effectively interrogate UAV-based images for detecting objects of
interest, such as humans, it is essential to acquire large-scale UAV-based
datasets that include human instances with various poses captured from widely
varying viewing angles. As a viable alternative to laborious and costly data
curation, we introduce Progressive Transformation Learning (PTL), which
gradually augments a training dataset by adding transformed virtual images with
enhanced realism. Generally, a virtual2real transformation generator in the
conditional GAN framework suffers from quality degradation when a large domain
gap exists between real and virtual images. To deal with the domain gap, PTL
takes a novel approach that progressively iterates the following three steps:
1) select a subset from a pool of virtual images according to the domain gap,
2) transform the selected virtual images to enhance realism, and 3) add the
transformed virtual images to the training set while removing them from the
pool. In PTL, accurately quantifying the domain gap is critical. To do that, we
theoretically demonstrate that the feature representation space of a given
object detector can be modeled as a multivariate Gaussian distribution from
which the Mahalanobis distance between a virtual object and the Gaussian
distribution of each object category in the representation space can be readily
computed. Experiments show that PTL results in a substantial performance
increase over the baseline, especially in the small data and the cross-domain
regime.Comment: CVPR 2023 (Selected as Highlight
Interaction induced ferro-electricity in the rotational states of polar molecules
We show that a ferro-electric quantum phase transition can be driven by the
dipolar interaction of polar molecules in the presence a micro-wave field. The
obtained ferro-electricity crucially depends on the harmonic confinement
potential, and the resulting dipole moment persists even when the external
field is turned off adiabatically. The transition is shown to be second order
for fermions and for bosons of a smaller permanent dipole moment, but is first
order for bosons of a larger moment. Our results suggest the possibility of
manipulating the microscopic rotational state of polar molecules by tuning the
trap's aspect ratio (and other mesoscopic parameters), even though the later's
energy scale is smaller than the former's by six orders of magnitude.Comment: 4 pages and 4 figure
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