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101.
Tatiana Kuznetsova Vladislav Sadykov Lubsan Batuev Ella Moroz Elena Burgina Vladimir Rogov Larissa Kurina Stylianos Neophytides 《Reaction Kinetics and Catalysis Letters》2005,86(2):249-256
Summary Dispersed samples of LaMnO3prepared viathe Pechini route and annealed at 500°C were doped with cations of a different charge and size (Ce, Fe, Bi, Sr+Bi). The effects
of doping on the structural features (XRD, IR) and reducibility (H2TPR) of these samples were considered. 相似文献
102.
This paper proposes a modified line search method which makes use of partial derivatives and re-starts the search process
after a given number of iterations by modifying the boundaries based on the best solution obtained at the previous iteration
(or set of iterations). Using several high dimensional benchmark functions, we illustrate that the proposed Line Search Re-Start
(LSRS) approach is very suitable for high dimensional global optimization problems. Performance of the proposed algorithm
is compared with two popular global optimization approaches, namely, genetic algorithm and particle swarm optimization method.
Empirical results for up to 10,000 dimensions clearly illustrate that the proposed approach performs very well for the tested
high dimensional functions. 相似文献
103.
Jing Zhang King-Wai Chu Ella B. Teague Randall E. Newmark Monte S. Buchsbaum 《Magnetic resonance imaging》2013
Functional magnetic resonance imaging (fMRI) studies have shown dysfunction in key areas associated with the thalamocortical circuit in patients with schizophrenia. This study examined the functional connectivity involving the frontal-thalamic circuitry during a spatial focusing-of-attention task in 18 unmedicated patients with schizophrenia and 38 healthy controls. Functional connectivity was analyzed by assigning seed regions (in the thalamic nuclei (mediodorsal nucleus (MDN), pulvinar, anterior nucleus (AN)), the dorsolateral prefrontal cortex (Brodmann areas 9 and 46), and the caudate), and correlating their respective activity with that in the non-seed regions voxel-wise. Functional connectivity analysis demonstrated that functional connectivity was significantly impaired in patients, e.g., between the right pulvinar and regions such as the prefrontal and temporal cortices and the cerebellum. On the other hand, enhanced functional connectivity was found in patients e.g., between the AN and regions such as the prefrontal and temporal cortices. In addition, the patients had significantly lower task performance and less (but non-significant) brain activation than those of controls. These results revealed disturbed functional integration in schizophrenia, and suggested that the functional connectivity abnormalities in the thalamocortical circuitry, especially the frontal-thalamic circuitry, may underlie the attention deficits in schizophrenia patients. Further, this study suggested that functional connectivity analysis might be more sensitive than brain activation analysis in detecting the functional abnormalities in schizophrenia. 相似文献
104.
Antifungal Hydrogels: Living Bacteria in Thermoresponsive Gel for Treating Fungal Infections (Adv. Funct. Mater. 40/2018)
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105.
A note on conserved charges of asymptotically flat and anti-de Sitter spaces in arbitrary dimensions
Ella Jamsin 《General Relativity and Gravitation》2008,40(12):2569-2590
The calculation of conserved charges of black holes is a rich problem, for which many methods are known. Until recently, there
was some controversy on the proper definition of conserved charges in asymptotically anti-de Sitter (AdS) spaces in arbitrary
dimensions. This paper provides a systematic and explicit Hamiltonian derivation of the energy and the angular momenta of
both asymptotically flat and asymptotically AdS spacetimes in any dimension D ≥ 4. This requires as a first step a precise determination of the asymptotic conditions of the metric and of its conjugate
momentum. These conditions happen to be achieved in ellipsoidal coordinates adapted to the rotating solutions. The asymptotic
symmetry algebra is found to be isomorphic either to the Poincaré algebra or to the so(D − 1,2) algebra, as expected. In the asymptotically flat case, the boundary conditions involve a generalization of the parity
conditions, introduced by Regge and Teitelboim, which are necessary to make the angular momenta finite. The charges are explicitly
computed for Kerr and Kerr–AdS black holes for arbitrary D and they are shown to be in agreement with thermodynamical arguments.
The author is a FRIA-FNRS bursar (National Fund for Scientific Research, Belgium). 相似文献
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109.
The synthesis of 4-methylxanthotoxin (X), 4,5′-dimethylxanthotoxin (XXIV) and the hitherto unknown 5′-methylxanthotoxin (XXIII) are described, using 6-allyl-7-hydroxy-8-methoxycoumarin (XV) and its 4-methyl derivative (XVII) as intermediates. 相似文献
110.
Evidence for Degradation of the Chrome Yellows in Van Gogh’s Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron‐Radiation‐Based X‐ray Techniques
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Dr. Letizia Monico Prof. Koen Janssens Dr. Ella Hendriks Frederik Vanmeert Dr. Geert Van der Snickt Dr. Marine Cotte Dr. Gerald Falkenberg Prof. Brunetto Giovanni Brunetti Dr. Costanza Miliani 《Angewandte Chemie (International ed. in English)》2015,54(47):13923-13927
This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh’s Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron‐radiation‐based X‐ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur‐rich PbCr1?xSxO4 (x≈0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., CrIII compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future. 相似文献