6,047 research outputs found
Application of Neural-Like P Systems With State Values for Power Coordination of Photovoltaic/Battery Microgrids
The power coordination control of a photovoltaic/battery microgrid is performed with a novel
bio-computing model within the framework of membrane computing. First, a neural-like P system with
state values (SVNPS) is proposed for describing complex logical relationships between different modes
of Photovoltaic (PV) units and energy storage units. After comparing the objects in the neurons with the
thresholds, state values will be obtained to determine the con guration of the SVNPS. Considering the
characteristics of PV/battery microgrids, an operation control strategy based on bus voltages of the point of
common coupling and charging/discharging statuses of batteries is proposed. At rst, the SVNPS is used to
construct the complicated unit working modes; each unit of the microgrid can adjust the operation modes
automatically. After that, the output power of each unit is reasonably coordinated to ensure the operation
stability of the microgrid. Finally, a PV/battery microgrid, including two PV units, one storage unit, and
some loads are taken into consideration, and experimental results show the feasibility and effectiveness of
the proposed control strategy and the SVNPS-based power coordination control models
Bis[2,6-bis(4,5-dihydro-1H-imidazol-2-yl)pyridine]manganese(II) bis(perchlorate) acetonitrile solvate
In the cation of the title compound, [Mn(C11H13N5)2](ClO4)2·CH3CN, the metal atom is located on a twofold rotation axis and is six-coordinated by six N atoms from two different 2,6-bis(4,5-dihydro-1H-imidazol-2-yl)pyridine (bip) ligands in a distorted octahedral geometry. The O atoms of the perchlorate anions are disordered with occupancies in the ratio 0.593 (10):0.407 (10). In the crystal, molecules are stabilized by two N—H⋯O hydrogen bonds, forming zigzag chains along the a axis, which are further interconnected by N—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.50 (1) Å] into a three-dimensional network
1,4-Bis(4,5-dihydro-1H-imidazol-2-yl)benzene–terephthalic acid–water (1/1/4)
The asymmetric unit of the title compound, C12H14N4·C8H6O4·4H2O, consists of one half of the 1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) molecule, one half of the terephthalic acid (TA) molecule and two water molecules. Both the bib and the TA molecules reside on crystallographic inversion centers, which coincide with the centroids of the respective benzene rings. The bib and the TA, together with the water molecules, are linked through intermolecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds, forming a three-dimensional network of stacked layers. Weak intermolecular C—H⋯O contacts support the stability of the crystal structure
1,4-Bis(4,5-dihydro-1H-imidazol-2-yl)benzene–4-aminobenzenesulfonic acid–water (1/2/2)
The asymmetric unit of the title compound, C12H14N4·2C6H7NO3S·2H2O, contains one half of a centrosymmetric 1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) molecule, one 4-aminobenzenesulfonic acid molecule and one water molecule. In the bib molecule, the imidazole ring adopts an envelope conformation. The benzene rings of bib and 4-aminobenzenesulfonic acid are oriented at a dihedral angle of 21.89 (4)°. In the crystal structure, intermolecular N—H⋯O, O—H⋯N and O—H⋯O interactions link the molecules into a three-dimensional network. Weak π–π contacts between the benzene and imidazole rings and between the benzene rings [centroid–centroid distances = 3.895 (1) and 3.833 (1) Å, respectively] may further stabilize the structure
Few-Shot Learning with a Strong Teacher
Few-shot learning (FSL) aims to train a strong classifier using limited
labeled examples. Many existing works take the meta-learning approach, sampling
few-shot tasks in turn and optimizing the few-shot learner's performance on
classifying the query examples. In this paper, we point out two potential
weaknesses of this approach. First, the sampled query examples may not provide
sufficient supervision for the few-shot learner. Second, the effectiveness of
meta-learning diminishes sharply with increasing shots (i.e., the number of
training examples per class). To resolve these issues, we propose a novel
objective to directly train the few-shot learner to perform like a strong
classifier. Concretely, we associate each sampled few-shot task with a strong
classifier, which is learned with ample labeled examples. The strong classifier
has a better generalization ability and we use it to supervise the few-shot
learner. We present an efficient way to construct the strong classifier, making
our proposed objective an easily plug-and-play term to existing meta-learning
based FSL methods. We validate our approach in combinations with many
representative meta-learning methods. On several benchmark datasets including
miniImageNet and tiredImageNet, our approach leads to a notable improvement
across a variety of tasks. More importantly, with our approach, meta-learning
based FSL methods can consistently outperform non-meta-learning based ones,
even in a many-shot setting, greatly strengthening their applicability
Effects of Astragalus
This paper studied the chronic fatigue induced by excessive exercise and the restoration effects of Astragalus polysaccharides (APS) on mitochondria. In vivo, we found that excessive exercise could cause oxidative stress statue which led to morphological and functional changes of mitochondria. The changes, including imbalance between mitochondria fusion-fission processes, activation of mitophagy, and decrease of PGC-1α expression, could be restored by APS. We further confirmed in vitro, and what is more, we found that APS may ameliorate mitochondrial dysfunction through Sirt1 pathway. Based on the results, we may figure out part of the molecular mechanism of mitochondrial amelioration by APS
2,3,5,6-Tetrafluoro-1,4-bis(2-pyridylmethyleneaminomethyl)benzene
The title compound, C20H14F4N4, is a flexible bis-pyridine-type ligand with an extended fluorinated spacer group between the two pyridyl functions. The centroid of the central aromatic ring is situated on a crystallographic center of inversion. The dihedral angle between the pyridine ring and the central benzene ring is 63.85 (9)°. The crystal structure exhibits intermolecular C—H⋯F hydrogen-bonding interactions
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