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951.
H. Ye P. Lu Z. Yu D. Wang Y. Liu 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,81(4):425-430
In this study, the significant effect of the nonuniform composition in alloy quantum dots (QDs) on electronic structure is
analyzed in depth. The equilibrium composition profiles in experimentally observed dome and barn shaped GeSi/Si QDs are determined
by combining the finite element method and the method of moving asymptotes. Due to the composition variation, the total band
edge of heavy hole is dominated by the band offset and spin-orbit coupling rather than the strain effect. The numerical results
reveal that the wave function of heavy hole trends to be localized in the Ge-rich region at the top of the large QD. Moreover,
the size effect gradually compensates the composition effect as the size of QD decreases. 相似文献
952.
We theoretically investigate surface plasmon resonance properties in Au and Ag cubic nanoparticles and find a novel plasmonic mode that exhibits simultaneous low extinction and high local field enhancement properties. We analyse this mode from different aspects by looking at the distribution patterns of local field intensity, energy flux, absorption and charge density. We find that in the mode the polarized charge is highly densified in a very limited volume around the corner of the nanocube and results in very strong local field enhancement. Perturbations of the incident energy flux and light absorption are also strongly localized in this small volume of the corner region, leading to both low absorption and low scattering cross section. As a result, the extinction is low for the mode. Metal nanoparticles involving such peculiar modes may be useful for constructing nonlinear compound materials with low linear absorption and high nonlinearity. 相似文献
953.
Xiao-Shan Ye 《Physica C: Superconductivity and its Applications》2011,471(23-24):1602-1605
We analyze the magnetic properties through two-orbital Hubbard model with the spin–orbit coupling (SOC) interaction in the iron-based superconductors. With the help of the Ising approximation for the Hund’s coupling between the itinerant electrons and the localized spins, we give a self-consistent account of the various magnetic orders observed in pnictides and the pairing symmetry. We also calculate the local density of states (LDOS) of the vortex state when a magnetic field is applied. The LDOS without SOC shows no resonant peak at the vortex core center in the superconducting state, while it shows an obvious resonant peak when SOC is applied. 相似文献
954.
Shuai Ye Hongli Suo Ziping Wu Min Liu Yan Xu Lin Ma Meiling Zhou 《Physica C: Superconductivity and its Applications》2011,471(7-8):265-269
The YBCO films with BaSnO3 (BSO) particles were prepared on LAO (0 0 1) substrates by metal organic deposition using trifluoroacetates (TFA-MOD) via introducing SnCl4 powders into the YBCO precursor solution. It was found that with the increase of the SnCl4 contents, the slower decomposition and higher temperature for nucleation during the reaction were requested compared to that of pure YBCO film. The YBCO films with different contents of Sn with dense surface and well c-alignment were obtained under optimized heat treatment, and the BaSnO3 phases were detected by XRD analysis. Litter effect of BSO particles on the Tc and Jc values of YBCO films was found. All YBCO films with BSO particles had Tc values over 90 K and Jc values over 1 MA/cm2. A significant enhancement of Jc was observed for YBCO films with BSO particles compared to that of pure YBCO film by the field dependence of Jc values. The best property was obtained for YBCO film with 6 mol.% Sn at 77 K under magnetic field. The results showed that the Jc value of YBCO film with 6 mol.% Sn was enhanced by a factor of 2 in 2 T, and over a factor of 10 beyond 4 T compared to that of pure YBCO film. 相似文献
955.
Ye Sun Stela Canulescu Peijie Sun Frank Steglich Nini Pryds Jørgen Schou Bo Brummerstedt Iversen 《Applied Physics A: Materials Science & Processing》2011,104(3):883-887
Thermoelectric FeSb2 films were produced by pulsed laser deposition on silica substrates in a low-pressure Ar environment. The growth conditions
for near phase-pure FeSb2 films were confirmed to be optimized at a substrate temperature of 425°C, an Ar pressure of 2 Pa, and deposition time of
3 h by ablating specifically prepared compound targets made of Fe and Sb powders in atomic ratio of 1:4. The thermoelectric
transport properties of FeSb2 films were investigated. Pulsed laser deposition was demonstrated as a method for production of good-quality FeSb2 films. 相似文献
956.
银杏叶中总硒和各种溶解形态硒含量随着季节而变化,实验研究了不同采摘期银杏叶中总硒及不同溶解态硒含量分布.7月、9月和霜降之后采摘的银杏叶总硒的含量分别为1.873,2.136,0.815 mg·kg-1,硒的形态以水溶态硒为主.银杏叶粗多糖含量分布依次为9月>7月>11月.7月份采集的银杏叶中得到粗多糖为棕褐色固体粉末... 相似文献
957.
化学计量学方法在三维荧光光谱分析中的应用 总被引:1,自引:0,他引:1
随着分析数据日益复杂,传统的用于光谱分析中的数据处理方法已不能满足分析需要,而化学计量学应用数学、统计学以及计算机等科学的方法与手段,设计和选择最优的量测方法,并通过对数据的解析,可最大限度的获取光谱数据中的有用信息.本文首先介绍了几类常用化学计量学方法分析的三维荧光光谱,其次介绍了常用于光谱分析的化学计量学方法,如统... 相似文献
958.
利用石墨炉(GF-990)原子吸收法,对蚯蚓诱导条件下黑麦草对土壤Cd吸收规律进行了研究.结果表明:(1)在3~6 mg·kg-1的Cd浓度范围内,黑麦草地下部分Cd含量与蚯蚓数量呈极显著正相关(γ=0.8832*~0.9862**),黑麦草地上部分Cd含量与蚯蚓数量的正相关性不显著(γ=0.3455~0.325 4);而土壤Cd含最与蚯蚓数量之间呈显著的负相关性(r=-0.5887~-0.6784*).(2)在相等数最的蚯蚓条件下,随着土壤中Cd浓度增加,黑麦草地上、地下部分Cd的含量均升高.(3)在相同的土壤环境下,蚯蚓数量与蚯蚓体内Cd含量呈极显著负相关(r=-0.982 0**~-0.9916**). 相似文献
959.
960.