1,611 research outputs found

    Phenolic Characteristics and Antioxidant Activity of Merlot and Cabernet Sauvignon Wines Increase with Vineyard Altitude in a High-altitude Region

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    Altitude, as an important factor in the expression of terroir, may affect wine quality. We evaluated the effect of altitude and its related climatic conditions on the phenolic characteristics and antioxidant activity of red wines made from grapes originating from high-altitude areas. The content of total phenolic compounds, total flavonoids and total anthocyanins increased with altitude in Merlot (ME) and Cabernet Sauvignon (CS) wines.  Cabernet Sauvignon wines showed richer tannins with increasing altitude.  Merlot and CS wines from higher altitude vineyards, showed a greater antioxidant capacity. Salicylic acid, syringic acid, caffeic acid, (+)-catechin, (−)-epicatechin, and the sum of individual phenolic compounds in the winesincreased with altitude based on the results of HPLC. The scores of the sensory evaluation of ME wines increased with higher altitude. The highest score was determined for CS wine originating from 2 608 m.  A clear grouping of wines according to grape cultivar and vineyard altitude was observed by principal component analysis. Regression analysis showed that altitude, followed by sunshine hours, made the greatest contribution to differences in the phenolic characteristics and antioxidant activity of red wines at different sites in a high-altitude region

    A Clustering Algorithm in Group Decision Making

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    The Riesz basis property of the eigenvectors connected to the exponential stability problem of a boundary damped tube carrying the stationary flow of a fluid

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    In the present paper we study the stability problem for a stretched tube conveying an ideal fluid with boundary damping. The spectral problem concerns operator functions of the forms \begin{equation*} \mathcal{M}\left(\lambda\right)=\lambda^2G+\lambda D+C\quad\text{and}\quad\mathcal{P}\left(\lambda\right)=\lambda I-T \end{equation*} taking values in different Hilbert spaces. Thorough analysis is made of the location and asymptotics of eigenvalues in the complex plane and Riesz basis property of the corresponding eigenvectors. Well-posedness of the initial-value problem for the abstract equation \begin{equation*} \dot{{x}}\left(t\right)=Tx\left(t\right) \end{equation*} is established as well as expansions of the solutions in terms of eigenvectors and exponential stability of the corresponding C0C_0-semigroup

    Spectral analysis of a viscoelastic tube conveying fluid with generalised boundary conditions

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    We study the spectral problem associated with the equation governing the small transverse motions of a viscoelastic tube of finite length conveying an ideal fluid. The boundary conditions considered are of general form, accounting for a combination of elasticity and viscous damping acting on both the slopes and the displacements of the ends of the tube. These include many standard boundary conditions as special cases such as the clamped, free, hinged, and guided conditions. We derive explicit asymptotic formulae for the eigenvalues for the case of generalised boundary conditions and specialise these results to the clamped case and the case in which damping acts on the slopes but not on the displacements. In particular, the dependence of the eigenvalues on the parameters of the problem is investigated and it is found that all eigenvalues are located in certain sectorial sets in the complex plane.Comment: typos correcte

    3-(2-Amino­ethyl)-2-(4-chloro­anilino)­quinazolin-4(3H)-one methanol 0.75-solvate

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    In the asymmetric unit of the title compound, C16H15ClN4O·0.75CH3OH, there are two independent quinazolin-4(3H)-one mol­ecules and one and a half methanol mol­ecules. One of the methanol mol­ecules is disordered over two positions with equal occupancies. The dihedral angles between the quinazoline ring system and the chloro­benzene ring in the two quinazolin-4(3H)-one mol­ecules are essentially the same, at 39.83 (1) and 39.84 (1)°. Intra­molecular N—H⋯N and O—H⋯O, and inter­molecular N—H⋯O and N—H⋯N hydrogen bonds are observed. In addition, π–π stacking inter­actions, with centroid-to-centroid distances of 3.654 (1), 3.766 (1) and 3.767 (1) Å, and weak C—H⋯π inter­actions, are observed

    DropMessage: Unifying Random Dropping for Graph Neural Networks

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    Graph Neural Networks (GNNs) are powerful tools for graph representation learning. Despite their rapid development, GNNs also faces some challenges, such as over-fitting, over-smoothing, and non-robustness. Previous works indicate that these problems can be alleviated by random dropping methods, which integrate noises into models by randomly masking parts of the input. However, some open-ended problems of random dropping on GNNs remain to solve. First, it is challenging to find a universal method that are suitable for all cases considering the divergence of different datasets and models. Second, random noises introduced to GNNs cause the incomplete coverage of parameters and unstable training process. In this paper, we propose a novel random dropping method called DropMessage, which performs dropping operations directly on the message matrix and can be applied to any message-passing GNNs. Furthermore, we elaborate the superiority of DropMessage: it stabilizes the training process by reducing sample variance; it keeps information diversity from the perspective of information theory, which makes it a theoretical upper bound of other methods. Also, we unify existing random dropping methods into our framework and analyze their effects on GNNs. To evaluate our proposed method, we conduct experiments that aims for multiple tasks on five public datasets and two industrial datasets with various backbone models. The experimental results show that DropMessage has both advantages of effectiveness and generalization

    Topological transitions in continuously-deformed photonic crystals

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    We demonstrate that multiple topological transitions can occur, with high-sensitivity, by continuous change of the geometry of a simple 2D dielectric-frame photonic crystal consisting of circular air-holes. By changing the radii of the holes and/or the distance between them, multiple transitions between normal and topological photonic band gaps (PBGs) can appear. The time-reversal symmetric topological PBGs resemble the quantum spin-Hall insulator of electrons and have two counter-propagating edge states. We search for optimal topological transitions, i.e., sharp transitions sensitive to the geometry, and optimal topological PBGs, i.e., large PBGs with clean spectrum of edge states. Such optimizations reveal that dielectric-frame photonic crystals are promising for optical sensors and unidirectional waveguides.Comment: submitted to Phys. Rev.

    Nucleon-nucleon interaction in the 3S1^3S_1-3D1^3D_1 coupled channel for a pion mass of 469 MeV

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    In this work, we apply the relativistic chiral nuclear force to describe the state-of-the-art lattice simulations of the nucleon-nucleon scattering amplitude. In particular, we focus on the 3S1^3S_1-3D1^3D_1 coupled channel for a pion mass of 469 MeV. We show that at leading order the relativistic chiral nuclear force can only describe δ3S1\delta_{3S1} and ε1\varepsilon_1 up to Tlab.≈10T_\mathrm{lab.}\approx10 MeV, while at the next-to-leading order it can do much better up to Tlab=200T_\mathrm{lab}=200 MeV. However, at the next-to-next-to-leading order, the description deteriorates, which can be attributed to the fact that the pion-mass dependence of the pion-nucleon couplings c1,2,3,4c_{1,2,3,4} may not be negligible. Furthermore, all the studies consistently yield negative δ3D1\delta_{3D1}, contrary to the lattice QCD results which are positive but consistent with zero. The present study is relevant to a better understanding of the lattice QCD nucleon-nucleon force and more general baryon-baryon interactions.Comment: Accepted for publication in PL
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