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931.
A simple method for real-time determination of the full three-dimensional orientation of the emission dipole of single molecules is presented. Introduction of a pi phase step in the back focal plane of the collector lens breaks the inherent symmetry, allowing the longitudinal dipole component to be measured. Experimental tolerances and the consequence of a nonzero bandwidth emission spectrum are also discussed. The scheme also allows for the longitudinal component of an electric field to be found experimentally. 相似文献
932.
Raphaël Côte Carlos E. Kenig Frank Merle 《Communications in Mathematical Physics》2008,284(1):203-225
Given g and f = gg′, we consider solutions to the following non linear wave equation :
Under suitable assumptions on g, this equation admits non-constant stationary solutions : we denote Q one with least energy. We characterize completely the behavior as time goes to ±∞ of solutions (u, u
t
) corresponding to data with energy less than or equal to the energy of Q : either it is (Q, 0) up to scaling, or it scatters in the energy space.
Our results include the cases of the 2 dimensional corotational wave map system, with target , in the critical energy space, as well as the 4 dimensional, radially symmetric Yang-Mills fields on Minkowski space, in
the critical energy space.
Centre National de la Recherche Scientifique.
Institut des Hautes études Scientifiques.
The work of R.C. and F.M. has been supported in part by ANR grant ONDE NONLIN, and the work of C.E.K. has been supported in
part by NSF. 相似文献
933.
We present photoluminescence spectroscopy of blend thin films of poly(9,9-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) with electron-donating copolymers under hydrostatic pressure. The photoluminescence spectrum of F8BT redshifts by 530+/-60 meV over pressures of 0.1 MPa-8.8 GPa. That of the interfacial charge-transfer exciton redshifts by 270-370 meV over a similar pressure range. Despite the relatively small shift of the charge-transfer exciton, the excited state dynamics at the molecular heterojunction are strongly enhanced due to the decreasing intermolecular distance, leading to favored exciplex emission. 相似文献
934.
935.
936.
Abdominal apparent diffusion coefficient measurements: effect of diffusion-weighted image quality and usefulness of anisotropic images 总被引:1,自引:0,他引:1
Yoshikawa T Ohno Y Kawamitsu H Ku Y Seo Y Zamora CA Aoyama N Sugimura K 《Magnetic resonance imaging》2008,26(10):1415-1420
This study aimed to assess the effect of diffusion-weighted image (DWI) quality on abdominal apparent diffusion coefficient (ADC) measurements and the usefulness of anisotropic images. Twenty-six patients (10 men and 16 women; mean, 58.1 years) who underwent DW imaging and were diagnosed not to have any abdominal diseases were analyzed. Single-shot spin-echo echo-planar DW imaging was performed, and one isotropic and three orthogonal anisotropic images were created. ADCs were calculated for liver (four segments), spleen, pancreas (head, body, tail) and renal parenchyma. Image quality for each organ part was scored visually. We estimated the correlation between ADC and image quality and evaluated the feasibility of using anisotropic images. ADCs and image quality were affected by motion probing gradient directions in the liver and pancreas. A significant inverse correlation was found between ADC and image quality. The r values for isotropic images were −.46, −.48, −.70 and −.28 for the liver, spleen, pancreas and renal parenchyma, respectively. Anisotropic images had the best quality and lowest ADC in at least one organ part in 17 patients. DWIs with the best quality among isotropic and anisotropic images should be used in the liver and pancreas. 相似文献
937.
We show that the number of photons in a strongly coupled exciton–photon system is asymmetric with the detuning of the modes when, in the spontaneous emission regime, the two modes are entangled. As changing the detuning is easy in semiconductor microcavities–where on the other hand the nature of the strong-coupling in terms of single-particle effects is not yet resolved–we propose this effect as a test of the quantum character of microcavity polaritons. 相似文献
938.
Landgrave-Barbosa Fernando Marmolejo-Valencia Andrés F. Baray-Calderón Alejandro Hu Hailin Aguilar-Cordero Julio César Amador-Bedolla Carlos Ugalde-Saldivar Víctor M. 《Journal of Solid State Electrochemistry》2022,26(3):649-661
Journal of Solid State Electrochemistry - A study of poly(3-hexylthiophene) (P3HT) thin films by spin-coating process, deposited on conducting glass substrates of fluorine-doped tin oxide (FTO), is... 相似文献
939.
Humberto Andre Potes-Lesoinne Fernando Ramirez-Alvarez Victor H. Perez-Gonzalez Sergio O. Martinez-Chapa Roberto Carlos Gallo-Villanueva 《Electrophoresis》2022,43(1-2):249-262
The survival of living beings, including humanity, depends on a continuous supply of clean water. However, due to the development of industry, agriculture, and population growth, an increasing number of wastewaters is discarded, and the negative effects of such actions are clear. The first step in solving this situation is the collection and monitoring of pollutants in water bodies to subsequently facilitate their treatment. Nonetheless, traditional sensing techniques are typically laboratory-based, leading to potential diminishment in analysis quality. In this paper, the most recent developments in micro- and nano-electrochemical devices for pollutant detection in wastewater are reviewed. The devices reviewed are based on a variety of electrodes and the sensing of three different categories of pollutants: nutrients and phenolic compounds, heavy metals, and organic matter. From these electrodes, Cu, Co, and Bi showed promise as versatile materials to detect a grand variety of contaminants. Also, the most commonly used material is glassy carbon, present in the detection of all reviewed analytes. 相似文献
940.
Hernández-Monje Diana Giraldo Liliana Moreno-Piraján Juan Carlos 《Journal of Thermal Analysis and Calorimetry》2020,142(4):1511-1522
Journal of Thermal Analysis and Calorimetry - Immersion enthalpies of activated carbons modified on their chemical surface were determined in benzene, cyclohexane, hexane, ethanol and water. Three... 相似文献