Direct measurement of the magnetic field effects on carrier mobilities and recombination in tri-(8-hydroxyquinoline)-aluminum based light-emitting diodes

The magnetic field effects on the carrier mobilities and recombination in tri-(8-hydroxyquinoline)-aluminum (Alq3) based light-emitting diodes have been measured by the method of transient electroluminescence. It is confirmed that the magnetic field has no effect on the electron and hole mobilities in Alq3 layers and can decrease the electron-hole recombination coefficient. The results imply that the dominant mechanism for the magnetic field effects in Alq3 based light-emitting diodes is the interconversion between singlet e-h pairs and triplet e-h pairs modulated by the magnetic field when the driving voltage is larger than the onset voltage of the electroluminescence.Comment: 14 pages, 4 figures,The revised version submitted to applied physics letter

Dynamic Adjustment of Display Luminance to Reduce Fingerprint Scanner Latency

Optical under display fingerprint scanners (UDFPS) are used for user authentication. The device screen provides illumination to UDFPS when capturing fingerprints through local high brightness mode (LHBM). However, on device screens that suffer from first frame dimming (FFD), this causes latency in reaching the target luminance required to accurately capture the fingerprint. Further, the latency may vary with the initial image being displayed on the screen or other factors such as ambient light, display brightness setting, etc. when the fingerprint authentication process is initiated. This disclosure describes techniques to dynamically apply different levels of compensation to the screen depending on the initial state of the device to compensate for first frame dimming. In the first technique, the actual luminance in the UDFPS region in the initial state is determined and is used to determine the required compensation. Content-dependent compensation is then applied. In the second technique, an image of known luminance is applied between after initiating authentication and before applying the target LHBM luminance. Due to the introduction of a pre-configured fixed value, overexposure and underexposure are automatically avoided

2-D Coherence Factor for Sidelobe and Ghost Suppressions in Radar Imaging

The coherence factor (CF) is defined as the ratio of coherent power to incoherent power received by the radar aperture. The incoherent power is computed by the multi-antenna receiver based on only the spatial variable. In this respect, it is a one-dimensional (1-D) CF, and thereby the image sidelobes in down-range cannot be effectively suppressed. We propose a two-dimensional (2-D) CF by supplementing the 1-D CF by an incoherent sum dealing with the frequency dimension. In essence, we employ both spatial diversity and frequency diversity which, respectively, enhance imaging quality in cross range and range. Simulations and experimental results are provided to demonstrate the performance advantages of the proposed approach.Comment: 7 pages, 21 figure

Relaxation Times for Chiral Transport Phenomena and Spin Polarization in Strongly Coupled Plasma

We compute the dynamical relaxation times for chiral transport phenomena in strongly coupled regime using the AdS/CFT correspondence. These relaxation times can be a useful proxy for the dynamical time scale for achieving equilibrium spin-polarization of quasi-particles in the presence of magnetic field and fluid vorticity. We identify the Kubo relations for these relaxation times and clarify some previous issues regarding time-dependence of the Chiral Vortical Effect. We study the consequences of imposing time-reversal invariance on parity-odd thermal noise fluctuations that are related to chiral transport coefficients by the fluctuation-dissipation relation. We find that time-reversal invariance dictates the equality between some of the chiral transport coefficients as well as their relaxation times.Comment: 30 pages, 7 figures, More references adde

Serum cystatin C and chemerin levels in diabetic retinopathy

Peer reviewedPublisher PD