6,842 research outputs found
The Influence of Augmented Reality Technology on the Learning Interest, Achievement of Learning Goals and Cognitive Load of Middle School Students
In order to test the influence of augmented reality technology on the learning interest achievement of learning goals and cognitive load the instruction of topographic map was taken as an example for experimental study This paper selected 427 students from 8 classes of Grade one who all come from Zhantan Middle School in Xindu District of Chengdu as experimental samples set two classes with similar level in learning as one group the one is the experimental class and the other is the control class and formed 4 groups in total The experimental classes adopted AR three-dimensional videos as teaching aids to give new lessons and the control classes adopted traditional two- dimensional videos and then the students learning interest level achievement of learning goals and cognitive load were measured The results showed that the application of AR technology in teaching could improve students learning interest and achievement of learning goals but had no effect on reducing cognitive loa
Description of a Sulfitobacter Strain and Its Extracellular Cyclodipeptides
A marine bacterium M44 was separated from 30 m deep seawater in the East China Sea (26° 28.3′ N 122° 29.0′ E) in 2006. 16S rDNA gene sequence comparison showed that the strain M44 was a member of the genus Sulfitobacter and highly similar to KMM 3554T. A series of experiments demonstrated that this strain M44 had many distinctive characteristics: its cells were gram-negative and mesophilic; its colonies were slightly yellowish, round, convex, and smooth; and it could grow at 10–28°C, pH 6.0–10.0, and in the presence of 0–12.5% (w/v) NaCl; the optimum growth conditions were 25°C and pH 7.0, and the optimum Na+ concentration was 2.5%. In addition, strain M44 contained 18 : 1 ω7c, 11 methyl 18 : 1 ω7c and 16 : 0 fatty acids as major fatty acids, and the genomic DNA G+C content was 58.04 mol%. According to our results of the secondary metabolites, six cyclodipeptides were isolated from the strain M44, which were Cyclo (Val-Leu), Cyclo (Phe-Val), Cyclo (Phe-Leu), Cyclo (Leu-Ile), Cyclo (Phe-Ile), and Cyclo (Trp-Pro). It is the first study of secondary metabolites isolated from this genus
FAC: 3D Representation Learning via Foreground Aware Feature Contrast
Contrastive learning has recently demonstrated great potential for
unsupervised pre-training in 3D scene understanding tasks. However, most
existing work randomly selects point features as anchors while building
contrast, leading to a clear bias toward background points that often dominate
in 3D scenes. Also, object awareness and foreground-to-background
discrimination are neglected, making contrastive learning less effective. To
tackle these issues, we propose a general foreground-aware feature contrast
(FAC) framework to learn more effective point cloud representations in
pre-training. FAC consists of two novel contrast designs to construct more
effective and informative contrast pairs. The first is building positive pairs
within the same foreground segment where points tend to have the same
semantics. The second is that we prevent over-discrimination between 3D
segments/objects and encourage foreground-to-background distinctions at the
segment level with adaptive feature learning in a Siamese correspondence
network, which adaptively learns feature correlations within and across point
cloud views effectively. Visualization with point activation maps shows that
our contrast pairs capture clear correspondences among foreground regions
during pre-training. Quantitative experiments also show that FAC achieves
superior knowledge transfer and data efficiency in various downstream 3D
semantic segmentation and object detection tasks.Comment: 11 pages, IEEE/CVF Conference on Computer Vision and Pattern
Recognition 2023 (CVPR 2023), the work is mainly supported by the Natural
Science Foundation Project of Fujian Province (2020J01826
Far-Field Tunable Nano-focusing Based on Metallic Slits Surrounded with Nonlinear-Variant Widths and Linear-Variant Depths of Circular Dielectric Grating
In this work, we design a new tunable nanofocusing lens by the linear-variant
depths and nonlinear-variant widths of circular grating for far field practical
applications. The constructively interference of cylindrical surface plasmon
launched by the subwavelength metallic structure can form a
subdiffraction-limited focus, and the focal length of the this structures can
be adjusted if the each groove depth and width of circular grating are arranged
in traced profile. According to the numerical calculation, the range of
focusing points shift is much more than other plasmonic lens, and the relative
phase of emitting light scattered by surface plasmon coupling circular grating
can be modulated by the nonlinear-variant width and linear-variant depth. The
simulation result indicates that the different relative phase of emitting light
lead to variant focal length. We firstly show a unique phenomenon for the
linear-variant depths and nonlinear-variant widths of circular grating that the
positive change and negative change of the depths and widths of grooves can
result in different of variation trend between relative phases and focal
lengths. These results paved the road for utilizing the plasmonic lens in
high-density optical storage, nanolithography, superresolution optical
microscopic imaging, optical trapping, and sensing.Comment: 14pages,9figure
Classical-driving-assisted quantum synchronization in non-Markovian environments
We study the quantum phase synchronization of a driven two-level system (TLS)
coupled to a structured environment and demonstrate that quantum
synchronization can be enhanced by the classical driving field. We use the
Husimi -function to characterize the phase preference and find the in-phase
and anti-phase locking phenomenon in the phase diagram. Remarkably, we show
that the classical driving enables a TLS to reach stable anti-phase locking in
the Markovian regime. However, we find that the synergistic action of classical
driving and non-Markovian effects significantly enhances the in-phase locking.
By introducing the -function and its maximal value to quantify the strength
of synchronization and sketch the synchronization regions, we observe the
typical signatures of the hollowed Arnold tongue in the parameter regions of
synchronization. In the hollowed Arnold tongue, the synchronization regions
exist both inside and outside the tongue while unsynchronized regions only lie
on the boundary line. We also provide an intuitive interpretation of the above
results by using the quasimode theory.Comment: 10 pages, 5 figures, revised versio
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