190 research outputs found
Rethinking Graph Regularization for Graph Neural Networks
The graph Laplacian regularization term is usually used in semi-supervised
representation learning to provide graph structure information for a model
. However, with the recent popularity of graph neural networks (GNNs),
directly encoding graph structure into a model, i.e., , has become
the more common approach. While we show that graph Laplacian regularization
brings little-to-no benefit to existing GNNs, and propose a simple but
non-trivial variant of graph Laplacian regularization, called
Propagation-regularization (P-reg), to boost the performance of existing GNN
models. We provide formal analyses to show that P-reg not only infuses extra
information (that is not captured by the traditional graph Laplacian
regularization) into GNNs, but also has the capacity equivalent to an
infinite-depth graph convolutional network. We demonstrate that P-reg can
effectively boost the performance of existing GNN models on both node-level and
graph-level tasks across many different datasets.Comment: AAAI202
Silicene Nanomesh
Similar to graphene, zero band gap limits the application of silicene in
nanoelectronics despite of its high carrier mobility. By using first-principles
calculations, we reveal that a band gap is opened in silicene nanomesh (SNM)
when the width W of the wall between the neighboring holes is even. The size of
the band gap increases with the reduced W and has a simple relation with the
ratio of the removed Si atom and the total Si atom numbers of silicene. Quantum
transport simulation reveals that the sub-10 nm single-gated SNM field effect
transistors show excellent performance at zero temperature but such a
performance is greatly degraded at room temperature
Preparation of supported skeletal Ni catalyst and its catalytic hydrogenation performance of C9 fraction from coking process
Currently, the inferior compressive strength of traditional Raney-Ni catalyst restricts its application in fixed-bed reactor. To approach this problem a series of supported skeletal Ni catalysts were prepared by mixing pseudo boehmite and Ni-Al alloy powder. In the process,the calcination temperature and atmosphere, mass ratio of pseudo boehmite to Ni-Al alloy powder and the sodium hydroxide solution concentration were investigated. The catalysts characterized by intelligent granule intensity tester(IGIT), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), X-ray diffraction (XRD),low temperature nitrogen adsorption, temperature programmed reduction of hydrogen (H2-TPR), and thermogravimetric-differential thermal analysis (TG-DTA).The results were shown that the calcination atmosphere had a considerable impact on the compressive strength of the catalyst. Compared with air atmosphere, the compressive strength of the catalyst increased from 12.62 N/mm to 23.96N/mm, obviously, in argon atmosphere, which was almost twice as much as the former.The inherent reason for this was that the argon obviously inhibited the transform of NiAl3 to Ni2Al3 in which the latter was the key factor to improve compressive strength. Additionally, coke-oven C9 hydrogenation was used to evaluate the performance of the catalyst and the results indicated that the conversion of indene, the key component of coke-oven C9, was as high as 90% in 1000h under the optimum reaction conditions:T=220oC, P(H2)=2.5MPa, H2/oil=200(v/v), LHSV=3.0h-1. Our data demonstrated that the supported skeletal Ni catalyst have a good industrial prospect in the fixed-bed reactor in future
Forest insurance market participants’ game behavior in China: an analysis based on tripartite dynamic game model
Purpose: In forest insurance market, there are three main participants including the insurance
company, the forest farmer and the government. As different participant has different benefit
object, there will be a complex and dynamic game relationship among all participants. The
purpose of this paper is to make the game relationship among all participants in forest
insurance market clear, and then to put forward some policy suggestions on the
implementation of forest insurance from the view of game theory.
Design/methodology/approach: Firstly, the static game model between the insurance
company and the forest farmer is set up. According to the result of static game model, it’s
difficult to implement forest insurance without government. Secondly, the tripartite dynamic
game model among the government, the insurance company and the forest farmer is proposed,
and the equilibrium solution of tripartite dynamic game model is acquired. Finally, the
behavioral characteristics of all participants are analyzed according to the equilibrium solution
of tripartite dynamic game model.
Findings: The government’s allowance will be an important positive factor to implement
forest insurance. The loss of the insurance company, which the lower insurance premium
brings, can be compensated by the allowance from the government. The more the government
provides allowance, the more actively the insurance company will implement forest insurance at a low insurance premium. In this situation, the forest farmer will be more likely to purchase the
forest insurance, then the scope of forest insurance implementation will expend.
Originality/value: There is a complex and dynamic game relationship among all participants
in forest insurance market. Based on the tripartite dynamic game model, to make the game
relationship between each participant clear is conducive to the implementation of forest
insurance market in China.Peer Reviewe
Super-resolution hyper-spectral imaging for the direct visualization of local bandgap heterogeneity
Optical hyperspectral imaging based on absorption and scattering of photons
at the visible and adjacent frequencies denotes one of the most informative and
inclusive characterization methods in material research. Unfortunately,
restricted by the diffraction limit of light, it is unable to resolve the
nanoscale inhomogeneity in light-matter interactions, which is diagnostic of
the local modulation in material structure and properties. Moreover, many
nanomaterials have highly anisotropic optical properties that are outstandingly
appealing yet hard to characterize through conventional optical methods.
Therefore, there has been a pressing demand in the diverse fields including
electronics, photonics, physics, and materials science to extend the optical
hyperspectral imaging into the nanometer length scale. In this work, we report
a super-resolution hyperspectral imaging technique that simultaneously measures
optical absorption and scattering spectra with the illumination from a
tungsten-halogen lamp. We demonstrated sub-5 nm spatial resolution in both
visible and near-infrared wavelengths (415 to 980 nm) for the hyperspectral
imaging of strained single-walled carbon nanotubes (SWNT) and reconstructed
true-color images to reveal the longitudinal and transverse optical
transition-induced light absorption and scattering in the SWNTs. This is the
first time transverse optical absorption in SWNTs were clearly observed
experimentally. The new technique provides rich near-field spectroscopic
information that had made it possible to analyze the spatial modulation of
band-structure along a single SWNT induced through strain engineering.Comment: 4 Figure
Isolation and identification of pathogens of Morchella sextelata bacterial disease
Morel mushroom (Morchella spp.) is a rare edible and medicinal fungus distributed worldwide. It is highly desired by the majority of consumers. Bacterial diseases have been commonly observed during artificial cultivation of Morchella sextelata. Bacterial pathogens spread rapidly and cause a wide range of infections, severely affecting the yield and quality of M. sextelata. In this study, two strains of bacterial pathogens, named M-B and M-5, were isolated, cultured, and purified from the tissues of the infected M. sextelata. Koch’s postulates were used to determine the pathogenicity of bacteria affecting M. sextelata, and the pathogens were identified through morphological observation, physiological and biochemical analyses, and 16S rRNA gene sequence analysis. Subsequently, the effect of temperature on the growth of pathogenic bacteria, the inhibitory effect of the bacteria on M. sextelata on plates, and the changes in mycelial morphology of M. sextelata mycelium were analyzed when M. sextelata mycelium was double-cultured with pathogenic bacteria on plates. The results revealed that M-B was Pseudomonas chlororaphis subsp. aureofaciens and M-5 was Bacillus subtilis. Strain M-B started to multiply at 10–15°C, and strain M-5 started at 15–20°C. On the plates, the pathogenic bacteria also produced significant inhibition of M. sextelata mycelium, and the observation of mycelial morphology under the scanning electron microscopy revealed that the inhibited mycelium underwent obvious drying and crumpling, and the healthy mycelium were more plump. Thus, this study clarified the pathogens, optimal growth environment, and characteristics of M. sextelata bacterial diseases, thereby providing valuable basic data for the disease prevention and control of Morchella production
Ecological niches and blood sources of sand fly in an endemic focus of visceral leishmaniasis in Jiuzhaigou, Sichuan, China
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