135 research outputs found
Locally Spontaneous Dynamic Oxygen Migration on Biphenylene: A DFT Study
The dynamic oxygen migration on the interface of carbon materials, such as
graphene and carbon nanotube, has opened up a new avenue to realizing the
dynamic covalent materials. However, the understanding of dynamic behaviors of
oxygen groups on the non-honeycomb structure, such as the biphenylene sheet, is
still limited. Using both density functional theory calculations and ab initio
molecular dynamics simulations, we demonstrate that the oxygen groups on the
biphenylene, which is an allotrope of graphene and composed of four-, six- and
eight-membered rings with unequal C-C bonds, can exhibit locally spontaneous
dynamic oxygen migration through the breaking/reforming of the C-O bond. The
density of state analyses show that the p-band center of the oxygen atom is
closer to the Fermi energy level on biphenylene, compared to that of the oxygen
atom adsorbed on graphene. This contrast confirms the locally spontaneous
dynamic activity of the oxygen atom on biphenylene. This work provides
scientific guidance for the exploration of the locally/globally spontaneous
dynamic covalent materials and adds a new member to the 2D dynamic covalent
material family.Comment: 13 pages, 4 figure
DDRF: Denoising Diffusion Model for Remote Sensing Image Fusion
Denosing diffusion model, as a generative model, has received a lot of
attention in the field of image generation recently, thanks to its powerful
generation capability. However, diffusion models have not yet received
sufficient research in the field of image fusion. In this article, we introduce
diffusion model to the image fusion field, treating the image fusion task as
image-to-image translation and designing two different conditional injection
modulation modules (i.e., style transfer modulation and wavelet modulation) to
inject coarse-grained style information and fine-grained high-frequency and
low-frequency information into the diffusion UNet, thereby generating fused
images. In addition, we also discussed the residual learning and the selection
of training objectives of the diffusion model in the image fusion task.
Extensive experimental results based on quantitative and qualitative
assessments compared with benchmarks demonstrates state-of-the-art results and
good generalization performance in image fusion tasks. Finally, it is hoped
that our method can inspire other works and gain insight into this field to
better apply the diffusion model to image fusion tasks. Code shall be released
for better reproducibility
Structures of minute virus of mice replication initiator protein N-terminal domain: insights into DNA nicking and origin binding
This is the author's accepted manuscript. The original is available at http://www.sciencedirect.com/science/article/pii/S0042682214005236Members of the Parvoviridae family all encode a non-structural protein 1 (NS1) that directs replication of single-stranded viral DNA, packages viral DNA into capsid, and serves as a potent transcriptional activator. Here we report the X-ray structure of the minute virus of mice (MVM) NS1 N-terminal domain at 1.45 Ă… resolution, showing that sites for dsDNA binding, ssDNA binding and cleavage, nuclear localization, and other functions are integrated on a canonical fold of the histidine-hydrophobic-histidine superfamily of nucleases, including elements specific for this Protoparvovirus but distinct from its Bocaparvovirus or Dependoparvovirus orthologs. High resolution structural analysis reveals a nickase active site with an architecture that allows highly versatile metal ligand binding. The structures support a unified mechanism of replication origin recognition for homotelomeric and heterotelomeric parvoviruses, mediated by a basic-residue-rich hairpin and an adjacent helix in the initiator proteins and by tandem tetranucleotide motifs in the replication origins
Oxygen dissociation on the C3N monolayer: A first-principles study
The oxygen dissociation and the oxidized structure on the pristine C3N
monolayer in exposure to air are the inevitably critical issues for the C3N
engineering and surface functionalization yet have not been revealed in detail.
Using the first-principles calculations, we have systematically investigated
the possible O2 adsorption sites, various O2 dissociation pathways and the
oxidized structures. It is demonstrated that the pristine C3N monolayer shows
more O2 physisorption sites and exhibits stronger O2 adsorption than the
pristine graphene. Among various dissociation pathways, the most preferable one
is a two-step process involving an intermediate state with the chemisorbed O2
and the barrier is lower than that on the pristine graphene, indicating that
the pristine C3N monolayer is more susceptible to oxidation than the pristine
graphene. Furthermore, we found that the most stable oxidized structure is not
produced by the most preferable dissociation pathway but generated from a
direct dissociation process. These results can be generalized into a wide range
of temperatures and pressures using ab initio atomistic thermodynamics. Our
findings deepen the understanding of the chemical stability of 2D crystalline
carbon nitrides under ambient conditions, and could provide insights into the
tailoring of the surface chemical structures via doping and oxidation.Comment: 23 pages,8 figure
A study on the double-edged sword effect of inclusive leadership on employees’ work behaviour—dual path perspective of cognition and affection
In order to cope with the volatile social environment and organisational change, more and more scholars call on leaders to stimulate subordinate effectiveness to a greater extent with inclusive behaviour. Existing studies focus on the positive impact of inclusive leadership, but ignore its potential negative impact. This study integrates Cognition-affection Personality System Theory to explore the double-edged sword mechanism of inclusive leadership on subordinates’ work behaviour. Through the data analysis of 518 paired questionnaires collected in three stages, the results are as follows: Inclusive leadership has a positive impact on subordinates’ psychological entitlement and state gratitude; Psychological entitlement and state gratitude play mediation roles not only between inclusive leadership and work withdrawal behaviour, but also between inclusive leadership and active behaviour; Subordinate narcissistic personality moderates the positive effect of inclusive leadership on psychological entitlement and state gratitude, and then moderates the indirect effect of inclusive leadership on subordinate work withdrawal behaviour and proactive behaviour through psychological entitlement and state gratitude. The above results expand the research on the action mechanism and boundary conditions of inclusive leadership in Chinese organisational context, and provide practical guidance for organisational managers to effectively conduct inclusive leadership
AssistSR: Task-oriented Video Segment Retrieval for Personal AI Assistant
It is still a pipe dream that personal AI assistants on the phone and AR
glasses can assist our daily life in addressing our questions like ``how to
adjust the date for this watch?'' and ``how to set its heating duration? (while
pointing at an oven)''. The queries used in conventional tasks (i.e. Video
Question Answering, Video Retrieval, Moment Localization) are often factoid and
based on pure text. In contrast, we present a new task called Task-oriented
Question-driven Video Segment Retrieval (TQVSR). Each of our questions is an
image-box-text query that focuses on affordance of items in our daily life and
expects relevant answer segments to be retrieved from a corpus of instructional
video-transcript segments. To support the study of this TQVSR task, we
construct a new dataset called AssistSR. We design novel guidelines to create
high-quality samples. This dataset contains 3.2k multimodal questions on 1.6k
video segments from instructional videos on diverse daily-used items. To
address TQVSR, we develop a simple yet effective model called Dual Multimodal
Encoders (DME) that significantly outperforms several baseline methods while
still having large room for improvement in the future. Moreover, we present
detailed ablation analyses. Code and data are available at
\url{https://github.com/StanLei52/TQVSR}.Comment: 20 pages, 12 figure
Multifaceted leaders: the double-edged sword effect of narcissistic leadership on employees’ work behavior
So far, most studies have focused on exploring the negative effects of narcissistic leadership. However, little attention has been paid to whether narcissistic leadership also has a positive effect. This study is based on Conservation of Resources Theory and reveals that narcissistic leadership has a double-edged sword effect. By using Mplus7.4 software the analysis of 450 employees and their direct leaders’ pairing data collected in three stages, it is found that: narcissistic leadership has a positive effect on employee’ hostility toward supervisor and psychological availability; hostility toward supervisor mediates the relationship between narcissistic leadership and counterproductive work behavior; psychological availability mediates the relationship between narcissistic leadership and organizational citizenship behavior; in addition, environmental uncertainty enhances the positive effect of narcissistic leadership on employee’ hostility toward supervisor and psychological availability, which in turn moderates the indirect effect of narcissistic leadership on counterproductive work behavior through employee’ hostility toward supervisor and on organizational citizenship behavior through psychological availability
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