2,685 research outputs found
First-principles study, fabrication and characterization of (Zr0.25Nb0.25Ti0.25V0.25)C high-entropy ceramic
The formation possibility of a new (Zr0.25Nb0.25Ti0.25V0.25)C high-entropy
ceramic (ZHC-1) was first analyzed by the first-principles calculations and
thermodynamical analysis and then it was successfully fabricated by hot
pressing sintering technique. The first-principles calculation results showed
that the mixing enthalpy of ZHC-1 was 5.526 kJ/mol and the mixing entropy of
ZHC-1 was in the range of 0.693R-1.040R. The thermodynamical analysis results
showed that ZHC-1 was thermodynamically stable above 959 K owing to its
negative mixing Gibbs free energy. The experimental results showed that the
as-prepared ZHC-1 (95.1% relative density) possessed a single rock-salt crystal
structure, some interesting nanoplate-like structures and high compositional
uniformity from nanoscale to microscale. By taking advantage of these unique
features, compared with the initial metal carbides (ZrC, NbC, TiC and VC), it
showed a relatively low thermal conductivity of 15.3 + - 0.3 W/(m.K) at room
temperature, which was due to the presence of solid solution effects,
nanoplates and porosity. Meanwhile, it exhibited the relatively high
nanohardness of 30.3 + - 0.7 GPa and elastic modulus of 460.4 + - 19.2 GPa and
the higher fracture toughness of 4.7 + - 0.5 MPa.m1/2, which were attributed to
the solid solution strengthening mechanism and nanoplate pullout and microcrack
deflection toughening mechanism.Comment: 49 pages,6 figures, 4 table
The impact of employee’s perception of organizational climate on their technology acceptance toward e-learning in South Korea
To better understand the relationship between e-learning integration and organizational factors in South Korea, this study explored the influence of employees’ perceptions of organizational climate on their technology acceptances toward e-learning in the workplace of South Korea. Employees’ perceptions of organizational climate was evaluated using Litwin & Stringer’s Organizational Climate Questionnaire (LSOCQ) and employees’ technology acceptance toward e-learning was measured by the Unified Theory of Acceptance and Use of Technology (UTAUT). A canonical correlation suggested that employees’ perceived organizational climate can influence their acceptance levels toward e-learning, which implies the importance of addressing organizational issues while integrating e-learning into workplaces in South Korea
Accelerating Antimicrobial Peptide Discovery with Latent Structure
Antimicrobial peptides (AMPs) are promising therapeutic approaches against
drug-resistant pathogens. Recently, deep generative models are used to discover
new AMPs. However, previous studies mainly focus on peptide sequence attributes
and do not consider crucial structure information. In this paper, we propose a
latent sequence-structure model for designing AMPs (LSSAMP). LSSAMP exploits
multi-scale vector quantization in the latent space to represent secondary
structures (e.g. alpha helix and beta sheet). By sampling in the latent space,
LSSAMP can simultaneously generate peptides with ideal sequence attributes and
secondary structures. Experimental results show that the peptides generated by
LSSAMP have a high probability of antimicrobial activity. Our wet laboratory
experiments verified that two of the 21 candidates exhibit strong antimicrobial
activity. The code is released at https://github.com/dqwang122/LSSAMP.Comment: KDD 202
4-(Anthracen-9-yl)-2-phenyl-6-(pyridin-2-yl)pyridine
In the title compound, C30H20N2, the anthracene ring system is approximately planar [maximum deviation = 0.035 (2) Å] and is nearly perpendicular to the central pyridine ring, making a dihedral angle of 75.73 (7)°. The terminal pyridine ring and the phenyl ring are oriented at dihedral angles of 8.11 (10) and 13.22 (10)°, respectively, to the central pyridine ring
Poly[(μ4-tetrazole-1-acetato-κ4 N 3:N 4:O:O′)silver(I)]
In the title complex, [Ag(C3H3N4O2)]n, the AgI atom is four-coordinated in a slightly distorted tetrahedral coordination geometry by two N atoms from two tetrazole-1-acetate (tza) ligands and two O atoms from the other two tza ligands. The tza ligand bridges two Ag atoms through the carboxylate O atoms and simultaneously binds to the other two Ag atoms through the tetrazole N atoms, forming a two-dimensional network parallel to (100)
Physiological and Metabolomic Alterations in Macrocystis pyrifera upon Exposure to Chromium(VI)
1593-1599In order to comprehensively characterize the effects of chromium (VI) on physiological and metabonomic performance of Macrocystis pyrifera, the sporophytes were exposed to 2 mg L-1 potassium dichromate for 3 days. M. pyrifera sporophytes showed decreased pigment content and Chla fuloresecnece parameters with the accumulation of Cr(VI). The carbon content was clearly increased, while the content of nitrogen, hydrogen and sulfur were little changed. Moreover, an untargeted metabolomic analysis was carried out in order to investigate the metabolic effects and to obtain a comprehensive profiling of induced metabolites during Cr stress. Absolute quantification of 14 different metabolites was obtained through GC-MS methods. The principal component analysis showed a clear separation between control and Cr treated samples. Some pathways including carbon fixation, sulfur metabolism, taurine and hypotaurine metabolism were affected by Cr (VI) stress. These findings provided valuable information to elucidate the mechanism of M. pyrifera upon Cr (VI) stress
Suppression of the multiplicity fluctuations in particle correlations
Multiplicity fluctuations play a crucial role in relativistic heavy-ion
collisions. In this work, we explore how the multiplicity fluctuations can be
effectively suppressed in the measurement of particle correlations. In
particular, through proper normalization, particle correlations can be
evaluated in a manner irrelevant to multiplicity. When the multiplicity
fluctuations are adequately extracted, Monte Carlo simulations show that the
remaining correlations possess distinct features buried in the otherwise
overwhelming fluctuations. Moreover, we argue that such a normalization scheme
naturally agrees with the multi-particle correlator, which can be evaluated
using the Q-vectors. The implications of the present study in the data analysis
are also addressed.Comment: 15 pages, 3 figure
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