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61.
A novel Fourier transform spectral interferometric (FTSI) multiplex coherent anti-Stokes Raman scattering (CARS) technique is developed to extract the vibrational spectrum equivalent to the spontaneous Raman scattering. The conventional FTSI method is modified to use the internal nonresonant CARS signal as a local oscillator to perform spectral interferometry. Utilizing the causality of the coherent vibration (i.e., there should be no signal before the laser excitation), this new FTSI method recovers the entire complex vibrational spectral parameters. We demonstrate this technique with a previously reported single-pulse multiplex CARS method that uses a single phase-controlled broadband ultrafast laser pulse. 相似文献
62.
Yongzhe Zhang Jooyoung Chung Juneyoung Lee Jihyun Myoung Sangwoo Lim 《Journal of Physics and Chemistry of Solids》2011,72(12):1548-1553
ZnO nanospheres were successfully synthesized by a hydrothermal process (S1 sample) and a wet-chemical method (S2 sample). Following synthesis, calcination treatment at 450 °C was performed for the sample prepared by the wet-chemical method (S3 sample). All of the samples possessed a regular spherical shape. A polycrystalline wurtzite structure was confirmed in the S1 and S3 samples by X-ray diffraction and selected area electron diffraction, whereas a mixture of ZnO nanoparticles and amorphous materials was observed in the sample S2. The surface area and pore structure of the samples were investigated by nitrogen adsorption–desorption measurements. Uniform nanopores with a diameter of 4.07 nm were present in the S1 sample while a broad pore size distribution was obtained for the S2 and S3 samples. The highest surface area was obtained for the S1 sample and a possible formation mechanism was studied. 相似文献
63.
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In an effort to understand and manipulate the complicated interactions in this system we are investigating their dependence on the relative orientation of the dipoles. By focusing a 480 nm beam from a tunable dye laser into a magneto-optical trap, we produce a nearly one-dimensional sample of Rydberg atoms. The trap lies at the center of four conducting rods with which we can vary the magnitude and direction of the electric field at the trap, thus controlling the orientation of the dipoles with respect to the sample axis. We have measured the strength of the interaction for a variety of relative orientations. 相似文献
64.
Eno S Auchincloss P Blanis D Bodek A Budd H Fry CA Harada H Ho YH Kim YK Kumita T Mori T Olsen SL Shaw NM Sill A Thorndike EH Ueno K Zheng HW Imlay R Kirk P Lim J McNeil RR Metcalf W Myung SS Cheng CP Gu P Li J Li YK Mao ZP Xu YT Zhu YC Abashian A Gotow K Hu KP Low EH Mattson ME Piilonen L Sterner KL Lusin S Rosenfeld C Wang AT Wilson S Frautschi M Kagan H Kass R Trahern CG Breedon RE Kim GN Ko W Lander RL Maeshima K Malchow RL Smith JR Stuart D Williams MC Abe K Fujii Y Higashi Y Kim SK 《Physical review letters》1989,63(18):1910-1913
65.
Shaw NM Blanis D Bodek A Budd H Coombes R Eno S Fry CA Harada H Ho YH Kim YK Kumita T Mori T Olsen SL Sill A Thorndike EH Ueno K Zheng HW Imlay R Kirk P Lim J McNeil RR Metcalf W Myung SS Cheng CP Gu P Li J Li YK Mao ZP Xu YT Zhu YC Abashian A Gotow K Hu K Low EH Mattson ME Naito F Piilonen L Sterner KL Lusin S Rosenfeld C Wang AT Wilson S Frautschi M Kagan H Kass R Trahern CG Breedon RE Kim GN Ko W Lander RL Maeshima K Malchow RL Smith JR Sparks K Williams MC Abe K Fujii Y Higashi Y Kim SK 《Physical review letters》1989,63(13):1342-1345
66.
Tae-Hwan Jung Soon-Il Kwon Jae-Hwan Park Dong-Gun Lim Young-Jin Choi Jae-Gwan Park 《Applied Physics A: Materials Science & Processing》2008,91(4):707-710
By using a thermal chemical vapor deposition and Au-catalyzed in situ alignment and growth process, SnO2 nanowires could be bridged across trenched electrodes. In this process, a complicated and individual alignment process could
be avoided and a number of devices can be fabricated in one step in a wafer scale. The gas-sensing characteristics of the
developed sensor were significantly better when compared to those of other types of NO2 sensors reported in the literature. When the concentration of NO2 was 5 ppm, the sensitivity was higher than 150. Especially, the reaction time of 8–14 s was noticeably fast, which is attributed
to the microtrench structure beneath the nanowires.
PACS 61.46.Fg; 85.35.Kt; 81.15.Gh 相似文献
67.
S. Sambasivam D. Paul Joseph Jung Hyun Jeong Byung Chun Choi Kwon Taek Lim Sang Su Kim Tae Kwon Song 《Journal of nanoparticle research》2011,13(10):4623-4630
Diluted magnetic semiconductor (DMS) nanoparticles of Sn1−x
Er
x
O2 (x = 0.0, 0.02, 0.04, and 0.1) were prepared by sol–gel method. The X-ray diffraction patterns showed SnO2 rutile structure for all samples with no impurity peaks. The decrease in crystallite size with Er concentration was confirmed
from TEM measurements (from 12 to 4 nm). The UV–Visible absorption spectra of Er-doped SnO2 nanoparticles showed blue shift in band gap compared to undoped SnO2. The electron spin resonance analysis of Er-doped SnO2 nanoparticles indicate Er3+ in a rutile lattice and also decrease in intensity with Er concentration above x = 0.02. Temperature-dependent magnetization studies and the inverse susceptibility curves indicated increased antiferromagnetic
interaction with Er concentration. 相似文献
68.
We propose and demonstrate a novel and simple dual-parameter measurement scheme based on a cascaded optical fiber device of long-period grating (LPG) and photonic crystal fiber (PCF) modal interferometer. The temperature and refractive index (RI) can be measured simultaneously by monitoring the spectral characteristics of the device. The implemented sensor shows distinctive spectral sensitivities of -30.82 nm/RIU (refractive index unit) and 47.4 pm/°C by the LPG, and 171.96 nm/RIU and 10.4 pm/°C by the PCF modal interferometer. The simultaneous measurement of the temperature and external RI is experimentally demonstrated by the sensor. The temperature shift and RI shift calculated by the sensor matrix agree well with the actual temperature and RI change in the experiment. 相似文献
69.
Microstructure effect on chemical etching behavior of the annealed Ti-6Al-4V and Ti-3Al-2.5V titanium (Ti) alloys was compared with that of unalloyed commercially pure titanium. The microstructural evolution of structure phases after annealing the titanium and its alloys at temperature near and above β transus and followed by furnace cooling to room temperature was studied using optical microscope, scanning electron microscope and X-ray diffraction techniques. The microstructure study illustrates that the heat treatment enhanced partitioning effect allows extensive formation of hemispherical and near spherical pits roughened surface to be readily acquired by chemically etching the annealed α + β titanium alloys. The kinetics of the chemical etching reaction process show a linear dependence on time. The annealed α + β titanium alloys that exhibit relatively lower weight loss and thickness reduction rate illustrate less chemical activity than the annealed unalloyed titanium. 相似文献
70.
The dry etching characteristics of transparent and conductive indium-zinc oxide (IZO) films have been investigated using an inductively coupled high-density plasma. While the Cl2-based plasma mixture showed little enhancement over physical sputtering in a pure argon atmosphere, the CH4/H2/Ar chemistry produced an increase of the IZO etch rate. On the other hand, the surface morphology of IZO films after etching in Ar and Ar/Cl2 discharges is smooth, whereas that after etching in CH4/H2/Ar presents particle-like features resulting from the preferential desorption of In- and O-containing products. Etching in CH4/H2/Ar also produces formation of a Zn-rich surface layer, whose thickness (∼40 nm) is well-above the expected range of incident ions in the material (∼1 nm). Such alteration of the IZO layer after etching in CH4/H2/Ar plasmas is expected to have a significant impact on the transparent electrode properties in optoelectronic device fabrication. 相似文献