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排序方式: 共有253条查询结果,搜索用时 140 毫秒
81.
B. M. Margosches L. Friedmann W. Tschörner L. Friedmann E. Scheinost und W. Austen 《Fresenius' Journal of Analytical Chemistry》1927,72(1-2):67-69
Ohne Zusammenfassung 相似文献
82.
Ohne Zusammenfassung 相似文献
83.
E. Herz K. W. F. Kohlrausch w. M. d. Akad. d. Wiss. H. Seewann-Albert 《Monatshefte für Chemie / Chemical Monthly》1946,76(2):93-99
Ohne ZusammenfassungMit 1 Abbildung. 相似文献
84.
K. A. Ashtiani J. L. Shohet F. S. B. Anderson D. T. Anderson J. B. Friedmann 《Plasma Chemistry and Plasma Processing》1992,12(2):161-175
The axial distribution of the electrostatic potentials ofan electron-cyclotron resonance (ECR) processing plasma confined in a do magnetic mirror geometry was characterized. The potential profiles far argon and helium at 8.0x 10–4 and 4.0 × 10–4 Torr were measured using electron emissive probes. The experimental measurements were then compared with the predictions of a one-dimensional, electrostatic, particle-in-cell computer code which runs on a personal computer. The potential profiles as predicted by the code showed good agreement with the experimental measurements. 相似文献
85.
Sans résumé 相似文献
86.
Franz Joseph Herz 《Analytical and bioanalytical chemistry》1890,29(1):581-582
87.
Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography 总被引:5,自引:0,他引:5
Herz PR Chen Y Aguirre AD Schneider K Hsiung P Fujimoto JG Madden K Schmitt J Goodnow J Petersen C 《Optics letters》2004,29(19):2261-2263
A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with <4-microm axial resolution by use of a femtosecond Cr:forsterite laser light source. The micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications. 相似文献
88.
We study the optical properties of excitons in one-dimensional (1D) nanostructures at low temperatures. In single CdSe/ZnS core-shell nanorods we observe a fine structure splitting and explain it by exchange interaction. Two peaks are observed with different degrees of linear polarization of DLP<0.85 and DLP>0.95. For small nanorod radii R< or =a(B)/2, an increase in the photoluminescence decay time is found when the temperature increases from 10 to 80 K. The observations are explained by a radius-dependent change in the symmetry of the 1D-exciton ground state which transforms from a dark state into bright states below a critical radius of R(crit) approximately 3.7 nm. 相似文献
89.
H. Eisele M. Naftaly R. Kamoua 《International Journal of Infrared and Millimeter Waves》2005,26(1):1-14
Efficient second-harmonic power extraction was demonstrated recently with GaAs tunnel injection transit-time (TUNNETT) diodes up to 235 GHz and with InP Gunn devices up to 325 GHz. This paper discusses the latest theoretical and experimental results from second-harmonic power extraction at submillimeter-wave frequencies and explores the potential of using power extraction at higher harmonic frequencies to generate continuous-wave radiation with significant power levels at frequencies above 325 GHz. Initial experimental results include output power levels of more than 50 W at 356 GHz from a GaAs TUNNETT diode in a third-harmonic mode and at least 0.2–5 W in the frequency range 400–560 GHz from InP Gunn devices in a third or higher harmonic mode. The spectral output of these submillimeter-wave sources was analyzed with a simple Fourier-transform terahertz spectrometer and, up to 426 GHz, with a spectrum analyzer and appropriate harmonic mixers. Initial experimental results from a GaAs/AlAs superlattice electronic device at D-band (110–170 GHz) and J-band (170–325 GHz) frequencies are also included. 相似文献
90.
Beljonne D Hennebicq E Daniel C Herz LM Silva C Scholes GD Hoeben FJ Jonkheijm P Schenning AP Meskers SC Phillips RT Friend RH Meijer EW 《The journal of physical chemistry. B》2005,109(21):10594-10604
Atomistic models based on quantum-chemical calculations are combined with time-resolved spectroscopic investigations to explore the migration of electronic excitations along oligophenylenevinylene-based chiral stacks. It is found that the usual Pauli master equation (PME) approach relying on uncoherent transport between individual chromophores underestimates the excitation diffusion dynamics, monitored here by the time decay of the transient polarization anisotropy. A better agreement to experiment is achieved when accounting for excitation delocalization among acceptor molecules, as implemented in a modified version of the PME model. The same models are applied to study light harvesting and trapping in guest-host systems built from oligomers of different lengths. 相似文献