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41.
An overview of current nuclear power generation and fuel cycle strategies in Europe is presented, with an emphasis on options for the management of separated plutonium in the medium to long term. Countries which have opted for reprocessing of spent fuel have had to contend with increasing inventories of separated plutonium. Of the various potential options for utilisation or disposition of these stockpiles, only light water reactor (LWR) mixed-oxide (MOX) fuel programmes are sufficiently technologically mature to be fully operational in several European countries at present. Such reprocessing-recycling programmes allow for a stabilisation of the overall separated plutonium stocks, but not for a significant reduction in the stockpile. Moreover, the quality of recycled plutonium decreases at each potential step of re-irradiation. Therefore, optimised or new ways of managing the plutonium stocks in the medium to long term are required. In the present overview we consider the most promising options for reactor utilisation of plutonium in both near-term future reactor and Generation IV systems. 相似文献
42.
Carnel L. Gordon I. Van Gestel D. Vanhaeren D. Eyben P. Beaucarne G. Poortmans J. 《Electron Device Letters, IEEE》2007,28(10):899-901
Thin-film polysilicon solar cells are a promising low-cost alternative for bulk silicon solar cells due to their reduced material thickness. Recently, we showed that the use of an amorphous silicon/polycrystalline silicon heterojunction emitter instead of a diffused homojunction emitter led to a boost in the open-circuit voltage by 90 mV. Now, we present a full evidence that shows that this improvement is related to the absence of dopant smearing along the grain boundaries. By using scanning spreading resistance microscopy, we found an enlargement of the junction area by a factor of five in case of a homojunction. The tips of the dopant spikes represent lowly doped areas with an enhanced recombination. 相似文献
43.
EM Hamilton 《Canadian Metallurgical Quarterly》1996,8(12):599-563
Nurse practitioners often manage pregnant women for many health problems. Early recognition, treatment, or timely referral of any infectious process, especially urinary tract infections, is crucial to an optimal pregnancy outcome. Knowledge of urinary tract anatomic and physiologic changes in pregnancy and bacterial features necessary for infection to occur expands understanding the foundation of urinary tract infection prevention and treatment. This article discusses urinary tract infections, specifically focusing on clinical features, diagnosis, and treatment measures among pregnant women. 相似文献
44.
45.
A visual–kinesthetic (V–K) dissociation procedure of neurolinguistic programming (NLP) was used in treating rape-induced anxiety and phobic reactions in 2 18- and 19-yr-old rape victims. NLP theory suggests that anxiety reactions experienced by rape victims is a function of the interrelated processes of synesthesia and anchoring. In these 2 case reports, the use of the V–K dissociation technique is explored. From this preliminary basis, further research entailing the use of this treatment procedure is suggested. Implications for clinical practice are noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
47.
Rats with lesions to prefrontal cortex (PFC) or caudate nucleus (CN) were compared on tests of conditional associative learning (CAL) that placed varying demands on conditional rule learning and working-with-memory operations that are essential for response selection. Damage to either structure impaired performance, but the respective deficits resulted from disruption of different processes. CN lesions produced a consistent learning deficit that was thought to reflect a basic impairment in forming stimulus-response (S-R) associations. The behavior of PFC rats was more variable and depended on task requirements. When S-R learning or response selection was relatively easy, the PFC was not critical. However, when either component was made more difficult, thus requiring the contribution of strategic processes, PFC damage produced profound impairments. In addition to clarifying the roles of the PFC and CN in CAL, the results provide further evidence that multiple brain regions participate in relatively simple behavioral tasks and that their respective contributions can be dissociated. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
48.
Gordon Chin 《Journal of Infrared, Millimeter and Terahertz Waves》1987,8(10):1219-1234
An optically pumped submillimeter laser operating in the 500 μm (600 GHz) to 100 μm (3 THz) spectral range is the primary and, at present, the only available local oscillator (LO) source for laboratory and astronomical heterodyne applications for this wavelength region. A short review of the state-of-the-art of submillimeter lasers as LO sources, with an emphasis given to receiver systems designed for airborne heterodyne observations, will be presented. The characteristics and prospects for constructing a spacequalifiable laser LO system will also be given. 相似文献
49.
Corrosion of iron-base alloys at 982°C (1800°F) by coal char is observed and the phase morphologies are discussed. No sulfidation was observed at 50 hr exposure. After 100 hr internal aluminum-rich sulfides were observed along with thick outer scales of iron oxide. The species causing the hightemperature-induced corrosion are probably sulfides and sulfates, present in most coal chars. Possible mechanisms for the corrosion are also discussed.Department of Materials Science and Mineral Engineering. 相似文献
50.
The oxidation of sulphide species in solution has been investigated on a gold electrode in borate solutions of pH 6.8 and 9.2 and in 1 mol dm?3 NaOH. Sub-monolayer coverage by sulphur occurs at underpotentials. At more positive potentials, multilayers of sulphur can be deposited. The reaction producing sulphur, and the reverse process, involve the formation of poly sulphides as intermediates. The predominant polysulphide intermediate is S 2 2? . Oxidation of sulphide to sulphate occurs to some extent in parallel with sulphur deposition. Both reactions are inhibited by the presence of a surface layer of sulphur. At high potentials, sulphur is oxidized to sulphate. 相似文献