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51.
The activation method is used to measure cross sections for the 51V(n, p)51Ti reaction from En = 2.856 to 9.267 MeV and for the 51V(n, α)48Sc reaction from 5.515 to 9.567 MeV. Both measurements utilize ENDF/B-V evaluated neutron-induced fission cross sections of 238U as a standard. The experimental results from this work are compared with corresponding ENDF/B-V evaluated cross sections for V and substantial differences are evident. The most significant difference is a tendency for the measured values to exceed evaluated ones by as much as 50% in the vicinity of 8 MeV. 相似文献
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53.
A rechargeable solid electrolyte cell has been developed using a high copper-ion-conductivity solid electrolyte, Rb4Cu16I7–Cl13+, a copper anode, and an intercalation cathode, TiS2. The open-circuit voltage was 0.59 V at 25° C. The cell yielded a current of several tens of microamperes at room temperature without appreciable polarization. The cell could be submitted to one hundred or more charge-discharge cycles without showing appreciable deterioration. 相似文献
54.
The concentration of the bare metal ions located in the Site II of the alkaline-earth Y zeolites was determined from the CO adsorption, and the concentration sequence was obtained as follows: SrY>CaY>MgY>BeY. This sequence corresponded well to the radius of exchanged cation. Catalytic activity of alkaline-earth Y zeolites for the disproportionation reaction of NO, further, was discussed, and activity order of per unit amount of bare Site II cation was determined as follows: BeY>MgY>CaY>SrY>BaY. This order corresponded well to the strength of the electrostatic field of alkaline-earth Y zeolites. 相似文献
55.
Jin-ichi Nakamura Yoichi Takahashi Shin-ichiro Izumi Masayoshi Kanno 《Journal of Nuclear Materials》1980,88(1):64-72
The heat capacities of metallic uranium and thorium from 80 to 1000 K have been determined by laser-flash calorimetry. The results on uranium agree very well with those in the literature over the temperature range investigated. The results on thorium are several percent lower than the heat-capacity values hitherto reported, while the enthalpy data at high temperatures in the literature are in good agreement with the present results. Shomate's analysis showed that the present results are the most consistent through the temperature range from 80 to 1000 K. On this, a revised table of thermodynamic functions of thorium from 80 to 1000 K is presented. The excess heat capacity on thorium has been found to be not appreciable up to 1000 K, in contrast with the large excess heat capacity above 300 K for uranium. 相似文献
56.
57.
Mismatch repair genes are involved in increasing the fidelity of replication by specific repair of DNA polymerase incorporation errors. In Escherichia coli, the best studied mismatch repair (MMR) pathway is the methyl-directed long patch repair system which is mediated by three gene products; MutS, MutL and MutH. These are conserved in higher eukaryotes. Mutations in human homologues of these proteins have been shown to be implicated in hereditary non-polyposis colorectal cancer (HNPCC). Alterations in the coding regions of MMR genes result in a mutator phenotype with marked instability of microsatellite sequences, indicative of a deficiency in DNA repair. 相似文献
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59.
Tsutomu Kanno Hiromasa Tamaki Masato Yoshiya Hiroshi Uchiyama Sachiko Maki Masaki Takata Yuzuru Miyazaki 《Advanced functional materials》2021,31(13):2008469
Mg3Sb2-based intermetallic compounds with exceptionally high thermoelectric performance exhibit unconventional n-type dopability and anomalously low thermal conductivity, attracting much attention to the underlying mechanisms. To date, investigations have been limited to first-principle calculations and thermodynamic analysis of defect formation, and detailed experimental analysis on crystal structure and phonon modes has not been achieved. Here, a synchrotron X-ray diffraction study clarifies that, against a previous view of a simple crystal structure with a small unit cell, Mg3Sb2 is inherently a heavily disordered material with Frenkel defects, charge-neutral defect complexes of cation vacancies and interstitials. Ionic charge neutrality preserved in Mg3Sb2 is responsible for exotic n-type dopability, which is unachievable for other Zintl phase materials. The thermal conductivity of Mg3Sb2 exhibits deviation from the standard T−1 temperature dependency with strongly limited phonon transport due to a strain field. Inelastic X-ray scattering measurement reveals enhanced phonon scattering induced by disorder. The results will draw renewed attention to crystal defects and disorder as means to explore new high-performance thermoelectric materials. 相似文献
60.
Experimental visualization of lithium diffusion in LixFePO4 总被引:2,自引:0,他引:2
Chemical energy storage using batteries will become increasingly important for future environmentally friendly ('green') societies. The lithium-ion battery is the most advanced energy storage system, but its application has been limited to portable electronics devices owing to cost and safety issues. State-of-the-art LiFePO4 technology as a new cathode material with surprisingly high charge-discharge rate capability has opened the door for large-scale application of lithium-ion batteries such as in plug-in hybrid vehicles. The scientific community has raised the important question of why a facile redox reaction is possible in the insulating material. Geometric information on lithium diffusion is essential to understand the facile electrode reaction of LixFePO4 (0相似文献