RE_(0.06)La_(0.94)Nb_2O_6Cl的制备与光谱性质(RE=Pr、Eu、Tb、Dy)

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。

Asesoría en diseño suministrada a la oficina de Expoartesanías 94 : informe noviembre 22 a diciembre 21 de 1994.

36 hojas.

94 GHz dual-reflector antenna with reflectarray subreflector

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.

Annotation of Case C-272/94, Criminal proceedings against Michel Guiot and Climatec SA, ECR 1996 I-1905

Employer's contributions - Loyalty stamps - Bad-weather stamps - Freedom to provide services - Posted Workers

Excavations on Gozo 1987-94.

Malone, C. and Stoddart, S. Malta Archaeological Review, 1996, 1, 1-5.

Recueil de poésies, par « HENRY BAULDE » (fol. 30, 32, 35, 36, 37, 39, 40, 43, 44, 46, 47, 56, 59, 60, 61, 65, 68, 69, 70, 73, 74), « ALAIN CHARRETIER » (fol. 15), « JEHAN DAUTON » (fol. 9), « JEHAN MAROT » (fol. 29, 30), « JEHAN MOLINET » (fol. 77, 85, 90, 93, 94, 95) et « JEHAN ROBERTET » (fol. 1, 75).

Commençant par : « Estant couché soubz ung myrthe plaisant, Et maintz chasteaulx en Espaigne faisant... » et finissant par : « Sans parage ou riens n'est nect, Moulu d'un groz Moulinet. Fin de la complaincte de Grece, composée par le dict Molinet » .

Optical Properties of Sb2Te3, and Dilute Magnetic Semiconductors Sb1.97 VO.03 Te3 and Sb1.94 CrO.06 Te3

This thesis reports on the optical properties of the dilute magnetic semiconductors, Sb1.97 V 0.03 Te3 and Sb1.94Cr0.06Te3, along with the parent compound Sb2Te3' These materials develop a ferromagnetic state at low temperature with Curie temperatures of 22 K and 16 K respectively. All three samples were oriented such that the electric field vector of the light was perpendicular to the c-axis. The reflectance profile of these samples in the mid-infrared (500 to 3000 cm-1) shows a pronounced plasma edge which retracts with decreasing temperature. The far-infrared region of these samples exhibits a phonon at ~ 60 cm-1 which softens as temperature decreases. Kramers-Kronig analysis and a Drude-Lorentz model were employed to determine the optical constants of the bulk samples. The real part of the optical conductivity is shown to consist of intraband contributions at frequencies below the energy gap (~0.26 eV) and interband contributions at frequencies above the energy gap. The temperature dependence of the scattering rate show that a mix of phonon and impurity scattering are present, while the signature of traditional spin disorder (magnetic) scattering was difficult to confirm.

2° Informe 94-95

UANL