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91.
Jerzy Haber Magorzata Nattich Tadeusz Machej 《Applied catalysis. B, Environmental》2008,77(3-4):278-283
Catalytic activity of γ-alumina supported rhodium catalysts in nitrous oxide decomposition into dinitrogen and dioxygen has been determined, the total conversion being reached at 450 °C. Rhodium is present at alumina surface in three forms: metal particles, Rh2O3 and rhodium zero valent atoms interacting with oxygen ions at the metal/support interface. Linear dependence of the catalytic activity on rhodium dispersion has been found. Deposition of alkali metal cations: Li, Na, K and Cs as promoters at the surface of alumina results in a considerable increase of rhodium dispersion and hence catalytic activity. The effect of promoters depends strongly on the speciation of alkali metals and rhodium used in the preparation of the catalyst. Both alkali metal cations and rhodium compete for the same OH groups at the alumina surface. The electronegativity of alkali metal oxides is much greater than that of alumina and their deposition increases the negative charge of surface oxide ions hindering the diffusion of rhodium and preventing the growth of its larger particles. 相似文献
92.
The effects of alumina, silica and carbon on hydrogen adsorption on nickel were studied by the temperature-programmed desorption (TPD) method. The examinations were carried out in the flow system, starting TP measurement at 100 K, which resulted in the formation of complete characteristics of the interaction of hydrogen with supported nickel. The examinations have shown that each support modifies in its own way the state of hydrogen adsorbed on nickel. Alumina and silica insignificantly affect hydrogen strongly adsorbed on nickel, but significantly affect hydrogen weakly adsorbed; in particular, the effect of silica depends qualitatively on the way of preparation of the examined sample. Carbon affects significantly both strongly and weakly adsorbed hydrogen. 相似文献
93.
Two experiments examined latencies of self-other similarity judgments. The judgments were obtained for traits for which self was prototypical, other was prototypical or neither was prototypical. Two question types used were as follows: self-as-referent questions ("How similar is X to you…?") and other-as-referent questions ("How similar are you to X…?"). Judgments were faster for self-prototypical traits than for neither-prototypical traits regardless of the question form. Judgments for other-prototypical traits were faster than judgments for neither-prototypical traits in the case of the other-as-referent questions, but not in the case of self-as-referent questions. Results support the notion that both self and representations of specific others serve as habitual reference points. However, they also suggest that, compared to other social prototypes, self is a more rigid reference point, which is not easily affected by linguistic factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Inclusion of flaxseed in turkey diets decreases the n‐6/n‐3 PUFA ratio and increases the proportion of biologically active EPA and DHA without affecting meat quality 下载免费PDF全文
95.
Dynamic experimental simulation of hydrogen oriented underground gasification of lignite 总被引:2,自引:0,他引:2
Krzysztof Stańczyk Krzysztof Kapusta Marian Wiatowski Jerzy ?wi?drowski Andrzej Kotyrba Jan Rogut 《Fuel》2010,89(11):3307-3314
The main goal of the study presented in the paper was to experimentally demonstrate the feasibility of lignite gasification to hydrogen-rich gas under the underground conditions simulated in the ex situ reactor. The in situ gasification conditions were simulated both in respect to the coal seam and the surrounding stratum. In the 54-h experiment the process of lignite gasification with oxygen and steam as gasifying medium was tested. The experiment was initially divided into three stages: the ignition stage, the oxygen stage and the steam stage.The gas produced in the steam gasification stage was characterized by the calorific value of 7.8 MJ/m3 and average hydrogen content of 46.3 vol.%. Unfortunately a rapid decrease in the temperature levels and in the amount of produced gas proved that the tested lignite of 53 vol.% moisture content was not suitable for steam gasification. A great amount of thermal energy was consumed for water evaporation which led to a considerable heat loss. An addition of stoichiometric amount of water in the system by adding steam caused the seam to extinguish. Thus only oxygen could be used as the gasifying medium in the gasification of the tested lignite. The average calorific value of gas produced in the stable operation during oxygen gasification stage equaled 5.2 MJ/m3 with the average gas production rate of 16.0 m3/h and the average hydrogen content in the produced gas of 26.4 vol.%. 相似文献
96.
Janina Kabatc Edyta Krzyżanowska Beata Jędrzejewska Marek Pietrzak Jerzy Pączkowski 《应用聚合物科学杂志》2010,118(1):165-172
Results of kinetic studies of two‐component photoinitiator systems used in the visible‐light photoinduced polymerization of 2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol triacrylate are presented. Nine different styrylquinolinum dyes coupled with n‐butyltriphenylborate as a coinitiator have been used as photoinitiating systems. Reactive radicals that initiate the polymerization are formed by the well‐known mechanism of photoinduced electron transfer between dye cations acting as electron acceptors and borate anions acting as electron donors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
97.
Sweeney JD Silk PJ Gutowski JM Wu J Lemay MA Mayo PD Magee DI 《Journal of chemical ecology》2010,36(12):1309-1321
The male-produced aggregation pheromones of Tetropium fuscum (F.) and T. cinnamopterum Kirby were identified as (2S,5E)-6,10-dimethyl-5,9-undecadienol by chemical analysis, synthesis, electronantennography, and field trapping; the compound
is here renamed “fuscumol”. The effect of fuscumol chirality, alone or with host volatiles, and fuscumol release rate on Tetropium spp. was tested in field-trapping experiments in Nova Scotia and Poland. Both (S)-fuscumol and racemic fuscumol synergized trap catches of male and female T. fuscum, T. cinnamopterum, and T. castaneum (L.) when combined with a blend of host monoterpenes and ethanol. Without added host volatiles, fuscumol was either unattractive
(in Nova Scotia) or only slightly so (in Poland). (R)-Fuscumol, alone or in combination with host volatiles, did not elicit increases in trap capture of any Tetropium species, relative to the controls. Fuscumol synergized attraction of both sexes to host volatiles, thus indicating it acts
as an aggregation pheromone. Sex ratio was often female-biased in traps baited with fuscumol plus host volatiles, and was
either unbiased or male-biased in traps with host volatiles alone. In traps with host volatiles and racemic fuscumol, mean
catches of Tetropium species were unaffected by fuscumol release rates ranging from 1 to 32 mg/d. The attraction of three different Tetropium species to the combination of (S)-fuscumol and host volatiles suggests that cross-attraction may occur where these species are sympatric, and that reproductive
isolation possibly occurs via differences in close-range cues. These results have practical applications for survey and monitoring
of T. fuscum, a European species established in Nova Scotia since at least 1980, and for early detection of T. castaneum, a European species not presently established in North America. 相似文献
98.
Hydrogasification reaction of chars produced from two rank coals was investigated in temperature up to 1173 K and pressure up to 8 MPa. The reactivity of the lignite Szczerców char has been found to be slightly higher than of the subbituminous coal Janina char produced at the same conditions. A high value of the char reactivity was observed to certain carbon conversion, above which a sharp drop takes place. It has been shown that to achieve proper carbon conversion the hydrogasification reaction must proceed at temperature above 1200 K. Based on the active centres theory the kinetic equations of the hydrogasification process were developed and the kinetic constants at the maximum reaction rate evaluated for the analyzed chars. 相似文献
99.
Electropolishing and passivation of NiTi shape memory alloy 总被引:2,自引:0,他引:2
Electropolishing of NiTi alloy has been investigated. The influence of polishing bath composition and the operating conditions instead of the conditions of the process on the quality of the surface, evaluated by AFM and SEM methods, was established. Morphologically uniform surfaces were obtained only in the case of solutions containing hydrofluoric and sulfuric acids. Electropolished samples were sterilized and thermally passivated, then their corrosion resistance was measured in Tyrode's physiological solution. It was established that already after the electropolishing the corrosion resistance of NiTi alloy increases due to the spontaneously formed TiO2 layer. The increase of the thickness of the layer during sterilization and thermal passivation causes further increase in the corrosion resistance. 相似文献