997 resultados para Lpo 94


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The magnetotransport properties of the two-dimensional (2D) electron gas confined in a modulation-doped Zn0.80Cd0.20Se/ZnS0.06Se0.94 single quantum well structure were studied at temperatures down to 0.35 K in magnetic fields up to 7.5 T. Well resolved 2D Shubnikovde Haas (SdH) oscillations were observed, although the conductivity of the sample in the as grown state was dominated by a bulk parallel conduction layer. After removing most of the parallel conduction layer by wet chemical etching the amplitude and number of SdH oscillations increased. From the temperature dependence of the amplitude the effective mass of the electrons was estimated as 0.17 m(0). Copyright (C) 1996 Published by Elsevier Science Ltd

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The development of quantum cascade laser at 2.94 THz is reported. The laser structure is based on a bound-to-continuum active region and a semi-insulating surface-plasmon waveguide. Lasing is observed up to a heat-sink temperature of 70 K in pulsed mode with light power of 4.75 mW at 10 K and 1 mW at 70 K. A threshold current density of 296.5 A/cm(2) and an internal quantum efficiency of 1.57 x 10(-2) per cascade period are also observed at 10 K. The characteristic temperature of this laser is extracted to be T-0 = 57.5 K.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

通过重离子融合蒸发反应16 O(82 Se +4n) 94 Mo布局了94 Mo核的高自旋态 .利用多探头探测器阵列GASP进行了在束γ测量 ,从而重新研究了94 Mo核的高自旋态能级结构 .基于新发现的一些重要的连接跃迁 ,对94 Mo核的高自旋态能级纲图做了重要修改 .将新的能级结构与壳模型计算进行了比较和讨论 .结果表明要正确的描述94 Mo核的高自旋态 (自旋值大于 14 )能级结构 ,应考虑价中子在d5/ 2 ,g7/ 2 和h11/ 2 轨道上的激发 .

Relevância:

20.00% 20.00%

Publicador:

Resumo:

High-spin level structures of 94,95Mo have been reinvestigated via the 16O(82Se, xnγ)94,95Mo(x = 4, 3) reactions at E(82Se) = 460 MeV. The previously reported level schemes of these two nuclei have been largely modified up to ∼11 MeV in excitation energy due to identifications of some important linking transitions. Shellmodel calculations have been made in the model space of π(p1/2, g9/2, d5/2)4 and ν(d5/2, s1/2, d3/2, g7/2, h11/2)2(3) and compared with the modified level schemes. The structures of the newly assigned high-spin states in 94,95Mo have been discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using a shell model which is capable of describing the spectra of upper g(9/2)-shell nuclei close to the N = Z line, we study the structure of two isomeric states 7(+) and 21(+) in the odd-odd N = Z nucleus Ag-94. It is found that both isomeric states exhibit a large collectivity. The 7(+) state is oblately deformed, and is suggested to be a shape isomer in nature. The 21(+) state becomes isomeric because of level inversion of the 19(+) and 21(+) states due to core excitations across the N = Z = 50 shell gap. Calculation of spectroscopic quadrupole moment indicates clearly an enhancement in these states due to the core excitations. However, the present shell model calculation that produces the 19(+)-21(+) level inversion cannot accept the large-deformation picture of Mukha et al.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

室温下,用94MeV的Xe离子辐照纳米晶和非晶硅薄膜以及单晶硅样品,辐照量分别为1.0×1011,1.0×1012和1.0×1013ions/cm2。所有样品均在室温下用UV/VIS/NIR光谱仪进行检测分析。通过对比研究了纳米晶、非晶、单晶硅样品的光学带隙随Xe离子辐照量的变化。结果表明,不同结构的硅材料中Xe离子辐照引起的光学带隙变化规律差异显著:随着Xe离子辐照量的增加,单晶硅的光学带隙基本不变,非晶硅薄膜的光学带隙由初始的约1.78eV逐渐减小到约1.54eV,而纳米晶硅薄膜的光学带隙则由初始的约1.50eV快速增大至约1.81eV,然后再减小至约1.67eV。对硅材料结构影响辐照效应的机理进行了初步探讨。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

通过对94.5 Mev ~(14)N+~(59)Co反应数据的处理,得到了Li-Ne产物出射的wilczynski图、角分布、电荷分布,并对它们做了一些常规的分析工作。在Feldmeier模型框架下对该系统作了经典轨道动力学计算,给出了计算结果并对它们做了说明。本工作为轻系统低轰击能量下周边碰撞的系统性研究提供了一些参考数据

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The pro sectile-like fragments of ~(16)O + ~(64)Ni Reaction (Elab = 96 MeV) were measured by using ionization chamber telescopes. The countour plots of d~36/dndEdz in TKE-θ plane angular distribution integrating over different TKE window. The z-distribution and angular distributions of different fragments from He to O were obtained. The main mechanisms dominating in this reaction were discussed

Relevância:

20.00% 20.00%

Publicador:

Resumo:

<正>美国生态学会(ESA)第94届年会于2009年8月2日到7日在新墨西哥州阿尔伯克基(Albuquerque)的国际会议中心举行,3000多人参加此次会议。会议主题是"Ecological Knowledge and a Global Sustainable Society"。8月2日下午5时,美

Relevância:

20.00% 20.00%

Publicador:

Resumo:

应用成年Wistar大鼠制作精索静脉曲张动物模型,术后3月,处死动物取出睾丸。以电子自旋共振(ESR)法测试睾丸组织的氧自由基相对自旋浓度,TBA法和化学发光法分别检测过氧化脂质(LPO)含量、超氧化物歧化酶(SOD)水平。实验结果表明,精索静脉曲张组(VG)左、右睾丸氧自由基自旋浓度明显高于假手术对照组(CG)(P<O.05);VG双睾LPO含量显著高于CG(P<0.01);睾丸氧自由基相对自旋浓度和LPO含量呈明显正相关(r=0.54,P<0.05);.VG双睾SOD水平均显著低于CG(P<0.01)。上述结果提示:精索静脉曲张大鼠睾丸组织中含有大量的氧自由基和LPO,损伤睾丸细胞及其各级生物膜,会导致睾丸生精功能紊乱造成不育,而睾丸氧自由基清除障碍可能是氧自由基浓度增高继之LPO含量增多的重要机制之一。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文采用真空下气体输运技术制备RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)小单晶和多晶粉末样品。测定其晶体结构与LaNb_2O_6Cl的晶体结构相同,为正交晶系;Eu_(0.06)La_(0.94)Nb_2O_6Cl小单晶的晶胞参数为:a=9.751,b=7.321,c=8.364。观察RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)的特征激发光谱和发射光谱及其能量传递现象。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The design, construction and measured performance is described of an offset parabolic reflector antenna which employs a reflectarray subreflector to tilt the focused beam from the boresight direction at 94 GHz. An analysis technique based on the method of moments (MoM) is used to design the dual-reflector antenna. Numerical simulations were employed to demonstrate that the high gain pattern of the antenna can be tilted to a predetermined angle by introducing a progressive phase shift across the aperture of the reflectarray. Experimental validation of the approach was made by constructing a 28 × 28 element patch reflectarray which was designed to deflect the beam 5° from the boresight direction in the azimuth plane. The array was printed on a 115 µm thick metal backed quartz wafer and the radiation patterns of the dual reflector antenna were measured from 92.6-95.5 GHz. The experimental results are used to validate the analysis technique by comparing the radiation patterns and the reduction in the peak gain due to beam deflection from the boresight direction. Moreover the results demonstrate that this design concept can be developed further to create an electronically scanned dual reflector antenna by using a tunable reflectarray subreflector.