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991.
Cécile Marie Denis Guillaneux Julia Bisson Muriel Pipelier Didier Dubreuil 《溶剂提取与离子交换》2013,31(2):292-315
Abstract The synthesis and evaluation of solvent extraction performance of N,N,N′,N′-tetraalkyl-6,6″-(2,2′:6′,2″-terpyridine)diamides and N,N′-diethyl-N,N′-diphenyl-6,6″-(2,2′:6′,2″-terpyridine)diamide are reported here. These new bitopic ligands were found to extract actinides in different oxidation states (U(VI), Np(V and VI), Pu(IV), Am(III), and Cm(III)) from 3 M nitric acid. The presence of three soft nitrogen donors led to the selective extraction of actinides(III) over lanthanides(III) (Ce, Eu) and the presence of two amide functional groups grafted to the terpyridine unit allowed the extraction to occur from a highly acidic medium by minimizing the basicity of the ligand. Ligands bearing long alkyl chains (C4 and C8) or phenyl groups showed increased performances in a polar diluent like nitrobenzene. 相似文献
992.
993.
DenisDoyle 《今日电子》2005,(1):77-78
当今最先进的集成电路(IC)制造工艺正在重新开拓工业市场。迄今为止,在电噪声环境中以高电压工作的数据转换器、放大器、开关、多路复用器和其他器件一直沿着减小制造工艺尺寸的发展路线不懈地努力。美国模拟器件公司(Analog Devices,Inc.,简称ADI)提出了iCMOSTM——工业CMOS制造工艺,这种创新的制造工艺技术使客户可以在采用亚微米尺寸工艺的器件上施加高达30V电压, 相似文献
994.
995.
Gradation-based framework for asphalt mixture 总被引:1,自引:0,他引:1
Aggregates are the major component of asphalt mixtures, greatly influencing the mixtures resistance to failure. The structure that is formed by the aggregates will depend mostly on the size distribution, shape and mineral composition. Coarse aggregate have a strong influence on the resistance to rutting, while fines provide stability to the mixture. In the present study a generalized framework is developed to identify the range of aggregate sizes which form the load carrying structure in hot mix asphalt and determine its quality. The method has been developed as a numerical procedure based on packing theory. Parameters like porosity and coordination number have been used to evaluate the quality of the load carrying structure and relate it to resistance to rutting. The framework has been evaluated on several field and laboratory mixtures and related to their rutting performance. The gradation analysis of the mixtures has compared favorably with the performances reported from the field and laboratory testing. The developed gradation analysis framework has proven to be a tool to identify those mixtures with a poor rutting performance based on the gradation of the aggregates. 相似文献
996.
Duarte Liliana Rico; Martin Sophie; Brouillet Denis 《Canadian Metallurgical Quarterly》2008,40(4):211
The purpose of this study is to examine whether the way in which adults process animate and inanimate objects is impacted by the distinctiveness of the object and whether processing ability varies with age and with the quality of aging (e.g. normal aging versus pathological aging). We examined the perceptual functioning of young adults, elderly subjects and patients suffering from Alzheimer's disease. Generally, the results do not support the distributed model of conceptual representation. However, they do demonstrate that the ability to recognize objects by their distinctiveness is affected by normal and pathological aging. A gradual deterioration in the ability to correctly perceive animate objects was also observed as pathological aging progressed. These results, as well as our methods of assessing semantic memory, are discussed in terms of their theoretical and practical implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
The DIONISIO code describes most of the main phenomena occurring in a fuel rod during normal operation of a nuclear power reactor. Starting from the irradiation history, the code predicts the temperature distribution, elastic and plastic stress and strain, creep, swelling and densification, release of fission gases, caesium and iodine to the internal rod volume, gas mixing, pressure increase, irradiation growth of the cladding, development of an oxide layer on its surface and hydrogen uptake, restructuring and grain growth in the pellet.This work presents the model of Zircaloy fracture included in the code DIONISIO 1.0. The model of pellet-cladding mechanical interaction (PCMI) provides the forces caused by the solid-solid contact which add to the changing internal pressure and to the constant external pressure. Besides, the program evaluates the effects of a corrosive atmosphere (stress corrosion cracking, SCC) internal or external. With these data, the code calculates the J integral around the tip of an initiated crack, and proceeds to analyze, according to the quantity of corrosive substance dissolved and the cladding stress field, if the crack remains unchanged, if it grows due to the I-SCC mechanism, or if propagation is ductile, following the R curve of the material.Results corresponding to different PHWR and PWR reactors are presented and compared with code results. In particular, good agreement is obtained in the simulation of MOX experiments, where the cladding failed due to propagation of cracks originated in SCC. 相似文献
998.
Alain Favre‐Réguillon Denis Murat Gérard Cote Micheline Draye 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(10):1497-1501
BACKGROUND: Cloud point extraction (CPE) is an attractive alternative to solvent extraction. However, comparisons between both techniques are lacking. In this paper, the extraction of uranium(VI) using 8‐hydroxyquinoline (HQ) as chelating agent was studied by CPE using Triton X‐114 as non‐ionic surfactant and by solvent extraction using CHCl3 as diluent. RESULTS: Using CPE, a quantitative extraction was observed for pH higher than 4.5 with a HQ/U ratio of 10. Using solvent extraction an increase in the HQ/U ratio up to 50 is necessary to obtain a near quantitative extraction. Both extraction systems were then compared with respect to the nature of extracted species, and the extraction constants determined using log‐log analysis of the extraction data. In the solvent extraction system, the extracted species were identified as UO2Q2 and the corresponding extraction constant was found to be log kex = ? 3.6 ± 0.2 on the molar scale. Considering that UO2Q2 is also the extracted species in CPE, a slightly higher extraction constant, i.e. log kex = ? 2.5 ± 0.3, was found. CONCLUSION: Such a small difference in favour of the CPE system may arise from the combination of various phenomena, including effects of temperature and effects of ‘extractant environment’. However, a change in the nature of the extracted species, namely from UO2Q2 in the solvent extraction system to the formation of adducts, i.e. UO2Q2(HQ) and UO2Q2(HQ)2 in the CPE system, due to higher HQ concentration in the surfactant‐rich phase compared with chloroform, cannot be precluded, but requires confirmation. Copyright © 2012 Society of Chemical Industry 相似文献
999.
Several regularities of the accumulation of vacuum arc metal macroparticles (MP) on the sample on repetitively pulsed biasing (105 Hz, 7 µs, ?0.5 kV to ?3.5 kV) have been investigated. It has been shown that the substrate temperature plays a very important role in controlling the MP amounts on the sample. A possibility to change the metal particle number density on the substrate in the range from 105/cm2 to 107/cm2, depending on bias pulse parameters, sample temperature, and ion plasma saturation current density, has been demonstrated. The shape of MPs and their adhesion to the substrate surface depends strongly on the MP energy balance in a high-voltage space charge sheath. 相似文献
1000.
Glioblastoma is the most frequent primary neoplasm of the central nervous system and still suffers from very poor therapeutic impact. No clear improvements over current standard of care have been made in the last decade. For other cancers, but also for brain metastasis, which harbors a very distinct biology from glioblastoma, immunotherapy has already proven its efficacy. Efforts have been pursued to allow glioblastoma patients to benefit from these new approaches, but the road is still long for broad application. Here, we aim to review key glioblastoma immune related characteristics, current immunotherapeutic strategies being explored, their potential caveats, and future directions. 相似文献