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31.
The aim of this paper is to investigate the influence of multi-valency of americium in its oxide for the lowering of the thermal conductivity and the uncertainty in measurement. In the present study, thermal conductivity of non-stoichiometric americium oxide was evaluated up to 2000 K by the non-equilibrium molecular dynamics calculations using the Born-Mayer-Huggins interatomic potential with the partially ionic model. The oxygen-to-americium ratio (O/Am) was varied from 1.6 to 1.9, which corresponded to the variation of the ratio of Am3+/Am4+. So, we prepared potential parameters for both Am3+ and Am4+. The calculated thermal conductivity of non-stoichiometric americium oxide decreased with an increase of temperature, and the degree of the temperature dependence became smaller with a decrease of the O/Am ratio. This was mainly caused by the phonon-scattering due to oxygen vacancies induced with Am3+ ions. Comparing two supercells in which (1) short-range ordered Am3+ clusters were contained and (2) Am3+ ions were randomly distributed, the thermal conductivity of the former seemed to be somewhat larger than that of the latter. 相似文献
32.
During January through December 1993, twelve symptomatic infants and children (6 females, 6 males) with human immunodeficiency virus infection were prospectively evaluated for their cardiovascular clinical manifestations and ventricular functions, using two-dimensional, M-mode and Doppler echocardiographic examination. From auscultation, the pulmonic component of the second heart sound was accentuated in 8 cases and the murmur of atrioventricula valve regurgitation and pericardial friction rub were audible in 7 and 6 patients, respectively. Cardiomegaly and venous congestion were present on chest roentgenogram in 6 cases and electrocardiogram was abnormal in 5. The echocardiogram demonstrated elevated pulmonary arterial pressure in 9 patients. There were 5 cases of non-tamponade pericardial effusion. Five patients had mitral and pulmonary insufficiency while six had tricuspid insufficiency. The ejection fraction and shortening fraction were increased in all. The incidence of pulmonary hypertension was more frequent than previously reported. 相似文献
33.
Optimizing the design of large-scale ground-coupled heat pump systems using groundwater and heat transport modeling 总被引:2,自引:0,他引:2
In order to predict the long-term performance of large-scale ground-coupled heat pump (GCHP) systems, it is necessary to take into consideration well-to-well interference, especially in the presence of groundwater flow. A mass and heat transport model was developed to simulate the behavior of this type of system in the Akita Plain, northern Japan. The model was used to investigate different operational schemes and to maximize the heat extraction rate from the GCHP system. 相似文献
34.
Hiromi Yamashita Yo Fujii Yuichi Ichihashi Shu Gou Zhang Keita Ikeue Dal Ryung Park Keiko Koyano Takashi Tatsumi Masakazu Anpo 《Catalysis Today》1998,45(1-4):221-227
Highly dispersed titanium oxide catalysts have been prepared within zeolite cavities as well as in the zeolite framework and utilized as photocatalysts for the reduction of CO2 with H2O to produce CH4 and CH3OH at 328 K. In situ photoluminescence, ESR, diffuse reflectance absorption and XAFS investigations indicate that the titanium oxide species are highly dispersed within the zeolite cavities and framework and exist in tetrahedral coordination. The charge transfer excited state of the highly dispersed titanium oxide species play a significant role in the reduction of CO2 with H2O with a high selectivity for the formation of CH3OH, while the catalysts involving the aggregated octahedrally coordinated titanium oxide species show a high selectivity to produce CH4, being similar to reactions on the powdered TiO2 catalysts. Ti-mesoporous molecular sieves exhibit high photocatalytic reactivity for the formation of CH3OH, its reactivity being much higher than the powdered TiO2 catalysts. The addition of Pt onto the highly dispersed titanium oxide catalysts promotes the charge separation which leads to an increase in the formation of CH4 in place of CH3OH formation. 相似文献
35.
Further Investigations on the Promoting Effect of Mesoporous Silica on Base-Catalyzed Aldol Reaction
Y. Kubota H. Yamaguchi T. Yamada S. Inagaki Y. Sugi T. Tatsumi 《Topics in Catalysis》2010,53(7-10):492-499
Addition of an ordered mesoporous silica to a mixture of an aldol reaction, comprising 4-nitrobenzaldehyde with acetone catalyzed by organic amines, caused significant increase in the reaction rate to afford the β-hydroxyketone in high yield. A cooperative effect between the surface silanol and amine was considered to be the likely reason for the rate-enhancement, which was supported by FTIR spectroscopy. 相似文献
36.
37.
The degradation characteristics and pathways of pentachlorophenol (PCP) by the photo-Fenton systems were studied in H2O2 aqueous solutions, which contained Fe(III) only [H2O2/Fe(III) system] and Fe(III) + humic acid (HA) [H2O2/Fe(III)/HA system] at pH 5.0. Although 40% of the PCP was degraded after 5 h of irradiation in the H2O2/Fe(III) system, more than 90% was degraded in the H2O2/Fe(III)/HA system. This shows that at pH 5.0 the degradation of PCP is clearly enhanced by the presence of HA in the photo-Fenton system. In the H2O2/Fe(III) system, the production of octachlorodibenzo-p-dioxin (OCDD) was detected, and 2-hydroxy nonachlorodiphenyl ether was also identified as a precursor of OCDD. However, no OCDD production was observed in the H2O2/Fe(III)/HA system. This indicates that the presence of HA represses the production of OCDD during the degradation of PCP by the photo-Fenton system. Such an effect by HA can be attributed to a reaction sequence wherein reaction intermediates derived from PCP, such as PCP., are incorporated into HA. This was verified by 13C NMR and pyrolysis-GC/MS studies. 相似文献
38.
I Tsuda T Takubo T Kamitani N Tatsumi 《Journal of Automated Methods and Management in Chemistry》2001,23(3):77-81
The newly developed QA-810V is an optional unit for the determination of five-part white blood cell differentials. It can be used together with the same manufacturer's haematology analyser which has been used in relatively small-sized laboratories. The present study evaluates the basic performance of the QA-810V and the MEK-8118 haematology analyser using routinely obtained blood specimens treated with ethylenedioaminetetraacetic acid-2K. In this evaluation, reproducibility was good and little carryover was found. Accurate measurements were possible for up to 24h of storage. Storage at 4 ( degrees )C yielded more stable measurements of complete blood counts and five-part differentials than storage at room temperature. A good correlation between findings with the MEK-8118 haematology analyser and those with the SE-9000 haematology analyser was found for complete blood counts. The leukocyte differential obtained with the QA-810V correlated well with eye counts, with r > 0.9 for percentages of neutrophils, lymphocytes and eosinophils. Scattergrams obtained with the QA-810V reflected the presence of abnormal cells. The performance of the QA-810V was excellent and it can improve the quality of testing in clinical laboratories. 相似文献
39.
It is shown that the space required for wordline/bitline routing leads to a quadratic multiport-storage-cell area increase with port number N, dominating from as little as N=2, N=6 for small ROM and large SRAM cell types, respectively. Larger N results in enormous area increases (e.g. by a factor of 80 for a 32-port SRAM)I making conventional multiport memories unacceptable for most practical applications 相似文献
40.
Tatsumi Ishihara Yuji YokoyamaFutoshi Kozono Hidemi Hayashi 《Journal of power sources》2011,196(16):6956-6959
Intercalation property of PF6− into graphitic carbon was studied for a hybrid capacitor with different ratio of cathode and anode amount. Graphene sheet distance increased with increasing PF6− intercalation amount and it saturated at 0.4 nm at high applied potential, which is corresponded to stage 2 structure. On the other hand, it was found that nano size pore into graphene sheet was introduced at higher applied potential with 20 times larger anode carbon and this nano porous carbon shows a large capacity for intercalation capacity of 147 mAh g−1. The estimated energy density of the hybrid capacitor using carbon with nano bubble structure was ca. 400 Wh kg−1. 相似文献