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排序方式: 共有875条查询结果,搜索用时 6 毫秒
871.
Takayuki Tomida Yusuke TsuyuguchiTakahito Arai Takuya BennoMichiyuki Chikawa Koji DouraMasaki Fukushima Kazunori HiyamaKen Honda Daisuke IkedaJohn N. Matthews Toru NakamuraDaisuke Oku Hiroyuki SagawaHisao Tokuno Yuichiro TamedaGordon B. Thomson Yoshiki TsunesadaShigeharu Udo Hisashi Ukai 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,654(1):653-660
872.
Viorel Sandu Petre Badica Gheorghe Aldica Marilena Ferbinteanu Yuichiro Hayasaka 《Journal of Superconductivity and Novel Magnetism》2014,27(8):1837-1843
We present the effect of single molecular magnet ([Fe(bpca) 2Dy(NO 3)4] ?H 2 O?4.5 CH 3 NO 2 and [Mn 2(naften) 2(CH 3COO)(CH 3OH)] ?BPh 4) thermolysis on the superconducting properties of polycrystalline MgB 2 samples when inserted and sintered by spark plasma sintering technique. As a result of pyrolysis, Fe- and Dy-magnetic compounds grow within the MgB 2 matrix and give a paramagnetic behavior in normal state, whereas the Mn-based compounds display negligible magnetic properties. We find that the magnetic critical current density of the as-obtained superconducting composites, as well as the pinning mechanism, is dependent on the magnetic background, with a noticeable advantage for the sample with magnetic compounds. 相似文献
873.
Masahiro Wasai Satoshi Murakawa Yuta Tamura Yuichiro Wada Yuki Aoki Ryuji Nomura Yuichi Okuda 《Journal of Low Temperature Physics》2010,158(1-2):268-274
We measured transverse acoustic impedance Z of normal fluid 3He at 46.6 MHz on a surface coated with a thin 4He film. The real component of the impedance, Z′, in the coated samples deviates from Z′ in the pure 3He in the low temperature region. Z′ on the coated samples is almost identical with Z′ in the pure sample at high temperature and gradually deviates below a particular temperature T onset . T onset is possibly the superfluid onset temperature of the 4He film pressurized by the bulk liquid 3He. The gradual decrease in Z′ means that the superfluid component in 4He film increases gradually, which is expected from the dynamic KT transition at high frequency. The thicker is the film, the higher is the T onset . The range of T onset we observed was between 40 and 160 mK. This is much lower than that at the saturated vapor pressure. Suppression of T onset achieved by the applied pressure from bulk liquid 3He was presumably caused by the dissolved 3He in the film, thickening of the inert layers and/or by the strong correlation effect. The result shows that the specularity of 3He quasiparticle scattering is strongly affected by superfluidity of the 4He film. 相似文献
874.
In situ infrared (IR) and Raman microspectroscopy have been conducted on Neoproterozoic, organic-walled microfossils (prokaryotic fossils) in doubly polished, petrographic thin sections in order to detect their spectral signatures. The microfossils are very well preserved and occur in black chert from the approximately 850 million-year-old Bitter Springs Formation, Northern Territory, Australia. Raman microspectroscopy on two species of microfossils, one a filament and the other a coccoid, shows disordered peaks (D peak, 1340 cm(-1)) and graphite peaks (G peak, 1600 cm(-1)), indicating that they consist of disordered carbonaceous materials. IR micro-mapping results of the filament reveal that the distributions of peak heights at 2920 cm(-1) (aliphatic CH(2)), 1585 cm(-1) (aromatic C-C), and 1370 cm(-1) (aliphatic CH(3)) match the shape of the filamentous microfossil. These results suggest that IR microspectroscopy can be used for in situ characterization of organic polar signatures that morphologically indicate microfossils embedded in chert by using doubly-polished rock (petrographic) thin section samples. Further, these methods can be applied to controversial microfossil-like structures to test their biogenic nature. 相似文献
875.
Permeation of zidovudine (AZT) and probenecid from an ethanol-isopropyl myristate (IPM) mixed system through rat skin was studied in a finite system. Several volume sizes of the ethanol-IPM mixed systems containing AZT and probenecid, both as suspensions, were applied on the skin of the hairless rat using a vertical glass cell, and the fractions of the drugs permeated in 8 hr Q%,8hr were determined. For the systems containing 40% ethanol, the Q%,8hr value decreased with the reduction of volume of the system applied, and the decreasing profile was similar to that calculated on the assumption that the permeability of the drug does not change with the volume of the sample applied. On the other hand, in the systems containing 10% or 20% ethanol, the Q%,8hr value showed a maximum when a specific volume of the sample was applied. Therefore, the effect of sample volume on the Q%,8hr value was different between the 40% ethanol-IPM system and the 10% or 20% ethanol-IPM system. Following pretreatment of the skin with 0.105 ml/cm2 of drug-free 40% ethanol-IPM for 2 hr, several volume sizes of 10% ethanol-IPM systems containing the drugs were applied on the skin to explain why the different profiles were observed in the system containing 10% or 20% ethanol. The results for pretreated skin suggest that the amount of ethanol in the systems with low ethanol concentration and small application volume is too small to exert an effect that enhances permeation of the drugs. In those systems, the integrated effect of ethanol on the skin would be important for the enhancing effect. Total volume, as well as concentration, of an enhancer should be set precisely in designing an efficient transdermal delivery system. 相似文献