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排序方式: 共有274条查询结果,搜索用时 140 毫秒
51.
We have investigated compositional plane of a wide band gap solid solution semiconductor Ca1−xCdxSe1−ySy (x0.32) using powder synthesis under thermal equilibrium condition. The solubility limit at 1273 K varies with respect to the Se concentration y, taking a minimum Cd solubility limit of 0.12 at y=0.8 and a maximum limit of 0.32 at y=1.0. It is found that the system can be lattice-matched to GaAs and InP under covering the energy band gap of ultraviolet–visible region. These results allow to design optoelectronic devices adopting the Ca1−xCdxSe1−ySy system. 相似文献
52.
Kyosuke Morimoto Thien Phuc Le Sudipta Kumar Manna I. N. Chaithanya Kiran Shinji Tanaka Masato Kitamura 《化学:亚洲杂志》2019,14(19):3221-3221
53.
Xiong DB Okamoto NL Waki T Zhao Y Kishida K Inui H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(9):2536-2542
Heusler phases, including the full- and half-Heusler families, represent an outstanding class of multifunctional materials on account of their great tunability in compositions, valence electron counts (VEC), and properties. Here we demonstrate a systematic design of a series of new compounds with a 2×2×2 superstructure of the half-Heusler unit cell in X-Y-Z (X=Fe, Ru, Co, Rh, Ir; Y=Zn, Mn; Z=Sn, Sb) systems. Their structures were solved by using both powder and single-crystal X-ray diffraction, and also directly observed by using high-angle annular dark-field imaging in a scanning transmission electron microscope (HAADF-STEM). The VEC values of these new compounds span a wide and continuous range comparable to those for the full- and half-Heusler families, thereby implying tunability in compositions and physical properties in the superstructure. In fact, we observed abnormal electrical properties and a ferromagnetic semiconductor-like behavior with a high and tunable Curie temperature in these superstructures. 相似文献
54.
A 3-trifluoroacetylaminophthalimide selectively distinguished LiI from other alkaline-metal iodides and lithium halides by a marked fluorescence colour change, from orange-yellow to sky-blue, subsequent to 254 nm photolysis. 相似文献
55.
Eiichi Masumoto Hiroshi Maruoka Fumi Okabe Sho Nishida Ryoko Tomita Toshihiro Fujioka Kenji Yamagata 《Journal of heterocyclic chemistry》2012,49(4):893-899
A novel synthetic route to 4‐pyridazineacetic acids 10 – 12 has been achieved by the ring‐expansion reaction of N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 – 9 . 1H‐Pyrazole‐4‐acetic acids 1 – 3 were reacted with iodoacetonitrile in the presence of triethylamine in refluxing acetonitrile to give the corresponding C‐cyanomethylated 1H‐pyrazole‐4‐acetic acids 4 – 6 as major products together with N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 and 8 as minor products. On the other hand, reactions of 1 and 3 with chloroacetonitrile in the presence of triethylamine in refluxing chloroform afforded the corresponding N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 and 9 as major products. Thermal treatment of 7 – 9 with sodium hydride in N,N‐dimethylformamide caused ring expansion to yield the corresponding 4‐pyridazineacetic acids 10 – 12 . 相似文献
56.
E. Kuzmann A. Vértes Y. Ujihira M. Fujinami P. Kovács S. Nagy T. Masumoto 《Hyperfine Interactions》1988,42(1-4):939-942
Mössbauer spectroscopy was used for studying the effect of hydrogenation on amorphous Fe90Zr10 and Fe89Zr11 alloys electrolytically charged to high hydrogen content. The differences observed between the room temperature Mossbauer spectra of uncharged and hydrogenated amorphous alloys can be attributed to a change in the Curie temperature. Up to a certain hydrogen content the Curie temperature increases with the hydrogen concentration while the Curie temperature goes thorough a maximum as the hydrogen content increases. 相似文献
57.
Takahiro Matsumoto Jifa Qi Yasuaki Masumoto Hidenori Mimura Nobuyoshi Koshida 《Journal of luminescence》1998,80(1-4):203-206
We determined the density of state distribution near the Fermi level in porous silicon from the analysis of the current–voltage (J–V) and the current–thickness (J–T) characteristics in the space-charge-limited-current (SCLC) regime. The distribution exhibits a minimum density at the Fermi level, which is similar to the U-shape-trap-distribution observed in crystalline Si–SiO2 interface or in amorphous Si. Theoretical analysis well explains both the J–V and the J–L characteristics, which implies that the current flow is entirely controlled by localized states situated at the quasi-Fermi level. 相似文献
58.
In order to achieve the highly accurate and precise multielement determination in environmental materials, the usefulness of the comparative standard provided by the processing method proposed previously for soil samples has been re-examined using calcareous loam soil, light sandy soil and river sediment as unknown samples. As a result, it was also demonstrated that concentrations of 15 trace elements in each sample can be determined effectively and reasonably. 相似文献
59.
E. Kuzmann A. Vértes Y. Ujihira M. Fujinami P. Kovács T. Ando T. Masumoto 《Hyperfine Interactions》1989,45(1-4):277-286
Transmission and conversion electron Mössbauer spectroscopy were used in order to get further information bout thé effect of hydrogenation in Fe89Zr11 amorphous alloys in connection with the observation that the magnetically split spectrum appearing at room temperature due to a moderate hydrogenation gradually collapses with increasing hydrogen content. The Mössbauer measurements were performed on differently hydrogenated amorphous samples aged at 150 °C 300 °C and 600 °C before the hydrogenation. The time dependence of hydrogenation has also been measured. From the changes of Mössbauer parameters depending on the annealing temperature as well as on the cathodic potential of hydrogenation (compared with the hydrogen concentration measured by gas chromatography) we can conclude that relaxation processes and structural changes, taking place in these amorphous alloys, influence the hydrogen uptake, already at relatively low temperatures. 相似文献
60.