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41.
Amziane A Amari M Mounier D Breteau JM Joly N Banchet J Tisseur D Gusev V 《Ultrasonics》2012,52(1):39-46
Laser ultrasonics was applied to the manufacturing control of the integrity (no failure) of coated spherical particles designed for High Temperature Reactors (HTR). This control is of major importance, since the coating of the nuclear fuel kernel is designed to prevent from the diffusion of fission products outside the particle during reactor operation. The SiC layer composing the coating is particularly important, since this layer must be an impenetrable barrier for fission products. The integrity of the SiC shell (no crack within the shell) can be assessed by the ultrasonic vibration spectrum of the HTR particle, which is significantly changed, compared to the reference spectrum of a defect-free particle. Spheroidal vibration modes of defect-free dummy particles with a zirconium dioxide (ZrO2) core were observed in the 2-5 MHz range. A theoretical analysis is presented to account for the observed vibration spectra of defect-free or cracked HTR particles. 相似文献
42.
Shun-ichi Amari 《Annals of the Institute of Statistical Mathematics》1989,41(4):623-648
Fisher information generally decreases by summarizing observed data into encoded messages. The present paper studies the amount of Fisher information included in independently summarized messages from correlated information sources; that is, the amount of Fisher information when sequences x
N
and y
N
of N independent observations of random variables x and y are encoded (summarized) independently of each other into meassages m
X
and m
Y
. The problem is to obtain the maximal amount of Fisher information when the size of the summarized data or Shannon message information is limited. The problem is solved in the case of completely compressed symmetric data summarization. An achievable bound is given in the general case. Information geometry, which is a powerful new differential geometrical method applicable to statistics and systems theory, is applied to this problem, proving its usefulness in information theory as well.The present work is supported in part by Grant-in-Aid for Scientific Research #61030014, Ministry of Education, Science and Culture of Japan. 相似文献
43.
J V Amari P R Brown P E Pivarnik R K Sehgal J G Turcotte 《Journal of chromatography. A》1992,590(1):153-161
The experimental anti-AIDS glycerophosphatidic acid: nucleoside (sn-1/sn-2 diacylglycerol:dideoxynucleotide) drugs 3'-azido-3'-deoxythymidine monophosphate diglyceride (AZT-MP-DG) and 2',3'-dideoxycytidine monophosphate diglyceride (ddC-MP-DG) were isolated and purified by reversed-phase high-performance liquid chromatography (HPLC). The chromatographic separation was based on the glycerophospholipid moiety of the drugs and detection of the nucleoside component. The separations were optimized on method development columns packed with the stationary phase to be used in the micro-preparative column and monitored by a UV detector. Fractions were collected and analyzed for purity by analytical-scale HPLC and by thin-layer chromatography (TLC). The purity of the recovered drugs based on UV and light-scattering detection and on TLC was greater than 99%. The purified compounds were isolated for studies on structure confirmation, physical, biophysical and formulation properties and anti-HIV efficacy in culture. 相似文献
44.
Shigenobu Funahashi Kimiyo Sengoku Toru Amari Motoharu Tanaka 《Journal of solution chemistry》1988,17(2):109-116
A convenient technique is described to determine reaction volumes by means of direct dilatometry. Reaction volumes were determined for the following complexation reactions: formation of monoamminenickel(II) in water (–0.1±0.5 cm3-mol–1); formation of the 1:1 nickel(II) complex with isoquinoline in methanol and ethanol (3.2±0.1 and 1.1±0.1 cm3-mol–1, respectively); formation of the 1:1 isothiocyanatoiron(III) complex in water, Me2SO, and DMF (8.9±0.2, 12.4±0.7, and 25.1±0.3 cm3-mol–1, respectively); formation of the 18-crown-6 potassium complex in water (10.9±0.2 cm3-mol–1). We discussed these values in terms of electrostriction and molecular size. 相似文献
45.
D. Amari J. M. Lopez Cuesta N. P. Nguyen R. Jerrentrup J. L. Ginoux 《Journal of Thermal Analysis and Calorimetry》1992,38(4):1005-1015
Calorimetric measurements of the heat of adsorption of CO2 on zeolites with variable content of mono- and divalent cations lead to common conclusions. High initial heats (up to 120 kJ·mol–1 for NaA), generally associated with a slow and activated rate of adsorption, are found for high contents of Na+, Li+ or Ca2+. They are attributed to a limited number of chemisorption sites (0.3 per cage in NaA).Physisorption results in lower heats (25–50 kJ·mol–1). The lowest values are obtained with partially or totally decationized zeolites. Transition metal cations induce frequently weaker interactions than IA or IIA. Finally the stronger the energy of adsorption is, the larger the adsorbed amount is.
Zusammenfassung Kalorimetrische Messungen der Adsorptionswärme von CO2 an Zeolithen mit einem unterschiedlichen Gehalt an ein- und zweiwertigen Kationen führen zu allgemeinen Schlußfolgerungen. Für einen hohen Gehalt an Na+, Li+ oder Ca2+ werden hohe Initiierungswärmen (bis zu 120 kJ·mol–1 für NaA) gefunden, die immer in Verbindung mit langsamen und aktivierten Adsorptionsgeschwindigkeiten auftreten. Dies wird einer begrenzten Anzahl an Stellen für die Chemisorption zugeschrieben (0.3 pro -Cage in NaA). Physisorption verursacht niedrigere Wärmen (25–50 kJ·mol–1). Die niedrigsten Werte erhält man mit teilweise oder total entkationisierten Zeolithen. Kationen von Übergangs-metallen verursachen häufig schwächere Wechselwirkungen als IA-oder IIA-Kationen. Je höher die Adsorptionsenergie, um so größer ist die adsorbierte Menge.相似文献
46.
Fatimah Mohammed Alzahrani Norah Salem Alsaiari Khadijah Mohammedsaleh Katubi Abdelfattah Amari Abubakr M. Elkhaleefa Faouzi Ben Rebah Mohamed A. Tahoon 《Molecules (Basel, Switzerland)》2021,26(16)
We report in the present study the in situ formation of magnetic nanoparticles (Fe3O4 or Fe) within porous N-doped carbon (Fe3O4/N@C) via simple impregnation, polymerization, and calcination sequentially. The synthesized nanocomposite structural properties were investigated using different techniques showing its good construction. The formed nanocomposite showed a saturation magnetization (Ms) of 23.0 emu g−1 due to the implanted magnetic nanoparticles and high surface area from the porous N-doped carbon. The nanocomposite was formed as graphite-type layers. The well-synthesized nanocomposite showed a high adsorption affinity toward Pb2+ toxic ions. The nanosorbent showed a maximum adsorption capacity of 250.0 mg/g toward the Pb2+ metallic ions at pH of 5.5, initial Pb2+ concentration of 180.0 mg/L, and room temperature. Due to its superparamagnetic characteristics, an external magnet was used for the fast separation of the nanocomposite. This enabled the study of the nanocomposite reusability toward Pb2+ ions, showing good chemical stability even after six cycles. Subsequently, Fe3O4/N@C nanocomposite was shown to have excellent efficiency for the removal of toxic Pb2+ ions from water. 相似文献
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