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The two techniques of luminescence and of infra-red spectrophotometry have been used in an attempt to characterize surface states of η-alumina. Infra-red absorption bands of hydroxyl groups of different coordinations are observed, in agreement with previous results, and evolution of hydroxyl groups according to different treatments allows a luminescence at about 440–450 nm excited at 350–360 nm to be ascribed to these groups. Luminescence with an apparent maximum of 390 nm excited at 250 nm is attributed to internal vacancies, and luminescence with a maximum at 480–500 nm excited at 270–280 nm is attributed to surface vacancies. 相似文献
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We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented
states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among
the spinors in the coupled state. 相似文献
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Souhir Boujday Dr. Juliette Blanchard Dr. Richard Villanneau Dr. Jean‐Marc Krafft Christophe Geantet Prof. Catherine Louis Dr. Michèle Breysse Dr. Anna Proust Prof. 《Chemphyschem》2007,8(18):2636-2642
We use polyoxometalates as precursors for the preparation of heterogeneous catalysts. In the starting molecular precursor [{Ru(C6Me6)}2Mo5O18{Ru(C6Me6)(H2O)}], three ruthenium arene fragments are supported on a formally lacunary Lindqvist‐type polyoxomolybdate. This species was introduced by incipient wetness impregnation into the porosity of a SBA‐15‐type mesoporous silica. The evolution of the system under reducing atmosphere is followed by several methods, such as temperature‐programmed reduction (TPR), Raman, and X‐ray absorption spectroscopy (XAS). The results indicate that the polyoxometalate structure is retained after grafting on silica and allows the stabilization of Ru0 nanoparticles after reduction. The resulting system exhibits interesting catalytic activity in benzene hydrogenation. 相似文献
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Thomas Fenzl Chadi Touma Christoph PN Romanowski Jörg Ruschel Florian Holsboer Rainer Landgraf Mayumi Kimura Alexander Yassouridis 《BMC neuroscience》2011,12(1):29
Background
Neuronal mechanisms underlying affective disorders such as major depression (MD) are still poorly understood. By selectively breeding mice for high (HR), intermediate (IR), or low (LR) reactivity of the hypothalamic-pituitary-adrenocortical (HPA) axis, we recently established a new genetic animal model of extremes in stress reactivity (SR). Studies characterizing this SR mouse model on the behavioral, endocrine, and neurobiological levels revealed several similarities with key endophenotypes observed in MD patients. HR mice were shown to have changes in rhythmicity and sleep measures such as rapid eye movement sleep (REMS) and non-REM sleep (NREMS) as well as in slow wave activity, indicative of reduced sleep efficacy and increased REMS. In the present study we were interested in how far a detailed spectral analysis of several electroencephalogram (EEG) parameters, including relevant frequency bands, could reveal further alterations of sleep architecture in this animal model. Eight adult males of each of the three breeding lines were equipped with epidural EEG and intramuscular electromyogram (EMG) electrodes. After recovery, EEG and EMG recordings were performed for two days. 相似文献6.
W Huang K Besar R Lecover AM Rule PN Breysse HE Katz 《Journal of the American Chemical Society》2012,134(36):14650-14653
We have increased organic field-effect transistor (OFET) NH(3) response using tris(pentafluorophenyl)borane (TPFB) as a receptor. OFETs with this additive could detect concentrations of 450 ppb v/v, with a limit of detection of 350 ppb, the highest sensitivity reported to date for semiconductor films; in comparison, when triphenylmethane (TPM) or triphenylborane (TFB) was used as an additive, no obvious improvement in the sensitivity was observed. These OFETs also showed considerable selectivity with respect to common organic vapors and stability toward storage. Furthermore, excellent memory of exposure was achieved by keeping the exposed devices in a sealed container stored at -30 °C, the first such capability demonstrated with OFETs. 相似文献
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MK Hossain-Ibrahim K Rezajooi JK MacNally MRJ Mason AR Lieberman PN Anderson 《BMC neuroscience》2006,7(1):8-21
Background
Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation. 相似文献10.
R. Bressat M. Breysse B. Claudel H. Sautereau R.J.J. Williams 《Journal of luminescence》1975,10(3):171-176
Photoluminescence and adsorboluminescence for pure and doped thorium oxide are compared and shown to be distinct. It is deduced from this comparison that the luminescence transitions are different. A tentative scheme for the adsorboluminescence mechanism is proposed. 相似文献