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921.
M. Austerer S. Schartner C. Pflügl A.M. Andrews T. Roch W. Schrenk G. Strasser 《Physica E: Low-dimensional Systems and Nanostructures》2006,35(2):234
We report second-harmonic (SH) and sum-frequency generation in GaAs-based quantum-cascade lasers. A doping dependence study of the second-order susceptibility in one of the investigated structure is shown. We also demonstrate that grating-coupled surface emission is a highly efficient way to couple out the SH radiation. 相似文献
922.
Analysis of a combined tip-tilt and deformable mirror 总被引:1,自引:0,他引:1
A deformable mirror mounted on a two-axis tilt platform can provide wavefront compensation at a single location in an adaptive optics system, resulting in a significant reduction in the number of optical components in the system and in a simplification of the alignment. However, the moment of inertia of a deformable mirror is significantly different from that of the monolithic mirror commonly mounted on a tilt platform. We report on what are to our knowledge the first experimental results of mounting a microelectromechanical deformable mirror onto a fast steering platform and the first observation that at low operating frequencies high-order deformation of the deformable mirror membrane was not recorded. 相似文献
923.
Microcavity THz quantum cascade laser 总被引:1,自引:0,他引:1
G. Fasching A. Benz R. Zobl A.M. Andrews T. Roch W. Schrenk G. Strasser V. Tamosiunas K. Unterrainer 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):316
We report operation of disk and ring shaped terahertz (THz) quantum-cascade lasers (QCLs) emitting in the THz region between 3.0 and 3.4 THz. The GaAs/Al0.15Ga0.85As heterostructure is based on longitudinal-optical phonon scattering for depopulation of the lower radiative state. A double metal waveguide is used to confine the whispering gallery modes in the gain medium. The threshold current density is at 5 K. 3D Finite-Difference Time-Domain (FDTD) simulations were performed to obtain the field distributions within a THz QCl resonator at different frequencies. 相似文献
924.
Kramer MA Andrews B Hugar DL Jaitli A Larsen SB Kline BP McEllen KN Agrawal N Su SM Dammu SA Kammeyer RM Ivanisevic A 《Langmuir : the ACS journal of surfaces and colloids》2010,26(23):18083-18088
Fourier transform infrared (FT-IR) spectroscopy is utilized to observe adsorbate interactions with a tissue-derived collagen scaffold extracted from the Bruch's membrane of pig eyes. The characterization includes conformational changes in isoleucine, polyisoleucine, collagen-binding peptide, RGD-tagged collagen-binding peptide, and laminin after adsorption onto the substrate. Isotopically labeled isoleucine is further utilized to understand changes in the biomolecular structure upon binding to a tissue-derived surface. The adsorbates associated with the collagen scaffold predominately through hydrophobic interactions and hydrogen bonding. The results of this study can be used to improve our understanding of surface chemistry changes during the engineering of biomimetic scaffolds before and after biomolecule adsorption. 相似文献
925.
Dr. Frederik Peschke Dr. Andrea Taladriz-Sender Dr. Matthew J. Andrews Prof. Allan J. B. Watson Prof. Glenn A. Burley 《Angewandte Chemie (International ed. in English)》2023,62(50):e202313063
Traditional approaches to bio-orthogonal reaction discovery have focused on developing reagent pairs that react with each other faster than they are metabolically degraded. Glutathione (GSH) is typically responsible for the deactivation of most bio-orthogonal reagents. Here we demonstrate that GSH promotes a Cu-catalysed (3+2) cycloaddition reaction between an ynamine and an azide. We show that GSH acts as a redox modulator to control the Cu oxidation state in these cycloadditions. Rate enhancement of this reaction is specific for ynamine substrates and is tuneable by the Cu:GSH ratio. This unique GSH-mediated reactivity gradient is then utilised in the dual sequential bio-orthogonal labelling of peptides and oligonucleotides via two distinct chemoselective (3+2) cycloadditions. 相似文献
926.
927.
928.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
929.
Bess Vlaisavljevich Laura Gagliardi Xuefeng Wang Binyong Liang Lester Andrews Ivan Infante 《ChemInform》2010,41(50):no-no
Reactions of laser‐ablated U atoms with P4 molecules in excess Ar or Ne during condensation at 5 K are monitored by FTIR spectroscopy. 相似文献