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排序方式: 共有451条查询结果,搜索用时 31 毫秒
441.
M. Takai S. C. Tsou P. H. Tsien D. Röschenthaler H. Ryssel 《Applied Physics A: Materials Science & Processing》1981,24(4):319-322
A Q-switched Nd: YAG laser with a pulse duration of 20 ns was used to investigate effects of laser annealing in gallium implanted
silicon. Rutherford backscattering and Hall-effect measurements were performed to evaluate the annealed layer. Differential
Hall-effect measurements were carried out to obtain carrier concentration profiles after annealing. It was found that a maximum
sheet carrier concentration of 8×1015 cm−2 can be obtained for a gallium implantation of 1016 cm−2 by laser annealing with an energy density of more than 1.0 J cm−2. Although the peak carrier concentration was found to be 8.0×1020 cm−3, the annealed layer showed polycrystalline structures even after annealing with an energy density up to 4J cm−2. The annealing took place in the solid phase in this energy density range. 相似文献
442.
443.
Hiroyuki Obase Haruki Takai Masayuki Teranishi Nobuhiro Nakamizo 《Journal of heterocyclic chemistry》1983,20(3):565-573
Structural modifications of 4-piperidylbenzimidazolinones (I) by replacing the benzimidazolinone group with other heterocycles (2-cyanoamino, 2-ethoxy, and 2-methylbenzimidazole and 2-cyanoamino-3,4-dihydroquinazoline) has been made and a number of new piperidines (II) were synthesized as potential antihypertensive agents. 相似文献
444.
445.
Y. Takahashi Y. Yoshida Y. Ichino Y. Takai Y. Takahashi M. Yoshizumi T. Izumi Y. Shiohara T. Kato 《Physica C: Superconductivity and its Applications》2011,471(21-22):937-939
We have reported SmBa2Cu3Oy (SmBCO) films on single crystalline substrates prepared by low-temperature growth (LTG) technique. The LTG-SmBCO films showed high critical current densities in magnetic fields compared with conventional SmBCO films prepared by pulsed laser deposition (PLD) method. In this study, to enhance critical current (Ic) in magnetic field, we fabricated thick LTG-SmBCO films on metal substrates with ion-beam assisted deposition (IBAD)-MgO buffer and estimated the Ic and Jc in magnetic fields.All the SmBCO films showed c-axis orientation and cube-on-cube in-plane texture. Tc of the LTG-SmBCO films were 93.1–93.4 K. Jc and Ic of a 0.5 μm-thick SmBCO film were 3.0 MA/cm2 and 150 A/cm-width at 77 K in self-field, respectively. Those of a 2.0 μm-thick film were 1.6 MA/cm2 and 284 A/cm-width respectively. Although Ic increased with the film thickness increasing up to 2 μm, the Ic tended to be saturated in 300 A/cm-width. From a cross sectional TEM image of the SmBCO film, we recognized a-axis oriented grains and 45° grains and Cu–O precipitates. Because these undesired grains form dead layers, Ic saturated above a certain thickness. We achieved that Ic in magnetic fields of the LTG-SmBCO films with a thickness of 2.0 μm were 88 A/cm-width at 1 T and 28 A/cm-width at 3 T. 相似文献
446.
Takai A Ataee-Esfahani H Doi Y Fuziwara M Yamauchi Y Kuroda K 《Chemical communications (Cambridge, England)》2011,47(27):7701-7703
A new type of platinum nanowire with a bumpy surface "Pt nanoworm" is electrochemically synthesized in mesochannels of mesoporous silica films with the assistance of a nonionic surfactant (C(16)EO(8)). 相似文献
447.
We have succeeded in the allylation of aromatic and olefinic C-H bonds of benzoic and acrylic acids using a rhenium catalyst, Re(2)(CO)(10). In this reaction, isomerization of the introduced allyl group to the 1-propenyl group did not occur. 相似文献
448.
Yoshiharu Uruno Akio Tanaka Kazuki Hashimoto Shinya Usui Yasunao Inoue Yasuko Konishi Atsushi Suwa Kentaro Takai Wataru Katoda Norio Fujiwara Takaaki Sumiyoshi 《Tetrahedron》2013
N,N-Dimethylcarbamoylation of the anilinic nitrogen atom N(1) on the spiro 7-azaindoline consists of two steps. The first step is N,N-dimethylcarbamoylation of the pyridyl nitrogen atom N(7), leading to the formation of an isolable intermediate. The second step is intermolecular migration of the N,N-dimethylcarbamoyl group from the pyridyl nitrogen atom N(7) to the anilinic nitrogen atom N(1). We accomplished optimization of the reaction conditions based on the revealed reaction mechanism and a large scale synthesis of compound 3 in quantitative yield. 相似文献
449.
Dibenzophosphole oxides were obtained from secondary hydrophosphine oxides with a biphenyl group by dehydrogenation via phosphine-hydrogen and carbon-hydrogen bond cleavage in the presence of a catalytic amount of palladium(II) acetate, Pd(OAc)(2). By using this reaction, a ladder-type dibenzophosphole oxide could also be synthesized by double intramolecular dehydrogenative cyclization. 相似文献
450.
D. A. Volgina E. A. Stepanidenko T. K. Kormilina S. A. Cherevkov A. Dubavik M. A. Baranov A. P. Litvin A. V. Fedorov A. V. Baranov K. Takai P. S. Samokhvalov I. R. Nabiev E. V. Ushakova 《Optics and Spectroscopy》2018,124(4):494-500
The interaction of gold nanoparticles (NPs) and semiconductor alloyed CdZnSe/ZnS quantum dots (QDs) in colloidal solutions is studied. It is shown that the photoluminescence intensity of QDs in a mixture decreases compared to that in the initial QD solution, which is caused by resonance nonradiative energy transfer from QDs to Au NPs in spontaneously formed aggregates. To control the formation of pairs of interacting QDs and Au NPs, we proposed have a method for creating QD–Au NP complexes bound by special molecules—ligands. It is shown that the morphology and optical properties of the samples obtained depend on the method of their preparation, in particular, on the chemical environment of QDs. It is found that the complexes form in the case of addition of hydrophilic Au NPs to hydrophobic QDs and that this almost does not change the optical properties of the latter compared to those of quasi-isolated QDs in colloidal solution. 相似文献