Alaibakhsh, HamzehKhabir, MehdiKarami, Mohammad Azim
8页
查看更多>>摘要：In a CMOS image sensor pixel, fast and complete charge transfer from pinned photodiode (PPD) is desired and necessary in some applications. In special cases such as time-of-flight imaging or large pinned photodiodes, the PPD potential well shape greatly affects the charge transfer performance and should be engineered carefully. In the present work, a PPD structure named as multi-level PPD is introduced and examined through simulation study. Moreover, a fast and effective way to analyze the pinning process for a lag-free design is introduced. It is concluded that the proposed PPD achieves fast and complete charge transfer without employing additional lithography masks or process steps. The proposed PPD is compared with a similar conventional rectangular pixel and 31% reduction in the charge transfer time is observed.
Thu, Vu ThiCuong, Nguyen ManhCao, Dao TranHung, Luu Tien...
10页
查看更多>>摘要：In recent years, the abuse of antibiotics in livestock and aquaculture has become a global concern, so the detection of antibiotic residues in food is a topic of growing interest. At present the surface-enhanced Raman scattering (SERS) technique is promising as a useful tool in trace detection of chemical substances including antibiotics. In this report, we present the trace detection of cip-rofloxacin - a widely used antibiotic by recording its SERS spectrum, using a SERS substrate made of silver nanostars (AgNSs) coated on an aluminum foil. In turn, AgNSs are colloidal star-shaped silver nanoparticles that have been very simply synthesized by a two-step chemical reduction of silver nitrate in an aqueous solution at room temperature with hydroxylamine followed by tri-sodium citrate. The synthesized AgNSs have a total size of 250-300 nm with many pointed arms of 60-80 nm length protruding from the central core. It was found that with a SERS substrate assembled from the above AgNSs coated on an aluminum foil, due to the synergistic effect be-tween AgNSs and aluminum foil, the Raman enhancement factor of the SERS substrate was increased significantly. As a result, a SERS substrate with a Raman enhancement factor as high as 4 x 109 was created and ciprofloxacin was detected to very low concentrations, with a detection limit of 0.23 ppb.
Khan, Mohd TaukeerShkir, Mohd.Alhouri, BaraaAlmohammedi, Abdullah...
10页
查看更多>>摘要：Herein, the impact of Gadolinium (Gd) doped cadmium sulphide (CdS) nanoparticles on the structural, optical, photophysical and electrical properties of poly(3-hexylthiophene) (P3HT) thin films have been investigated. The structural, morphological and vibrational properties of fabricated films were probed by measuring X-ray diffraction spectra, scanning electron microscope images and FT-Raman spectra, respectively. The absorption spectra of P3HT thin films was noted to be red shifted and energy bandgap slightly decreases with incorporation of Gd:CdS nano particles. The extinction coefficient (k), refractive index (n) and dielectric constants (epsilon(r), epsilon(i)) of pure and hybrid films were extracted from spectroscopic ellipsometer data fitted by new amorphous dispersion model (for P3HT) and Adachi-New Forouhi dispersion model (for CdS) and noted that the optical constants decreases with increase of Gd:CdS nanoparticles concentrations. The photoluminescence intensity of P3HT/Gd:CdS films was quenched as compare to pristine P3HT, also an additional bands observed in hybrid films corresponds to emission from Gd:CdS nanoparticles. The average fluorescence life times of pristine P3HT thin films was evaluated to be 154 ps which drop to 109 ps for hybrid film, ascribes to formation of additional decay paths created due to Gd: CdS doping. The electrical resistivity (rho) and mobility (mu) of P3HT films were measured from Hall Effect systems and noted to be decreases for hybrid films whereas charge carrier concentration (n(C)) and sheet resistance (R-S) increases.
Shoaib, M.Khan, I.Iskakova, KulpashAlam, Mohammad Mahtab...
7页
查看更多>>摘要：10BaO-10ZnO-10Gd(2)O(3)-69P(2)O(3)-1Ho(2)O(3) (ZBOH) and 10BaO-10ZnO-10GdF3-69P(2)O(3)-1Ho(2)O(3) (ZBFH) were developed by the melt-quenched-method. The synthesized ZBOH and ZBFH glass samples were characterized for Uv-Vis-NIR, excitation, emission, decay time profile measurements and physical properties. It is observed that the ZBOH glass have higher density and refractive index as compared to the ZBFH glass. From the band gap calculation, it is observed that the oxyfluoride glasses have lower band gap as compared to the oxide glasses which indicate more \non bridging oxygen in oxyfluoride glasses. The emission spectra recorded at lambda(ex )= 449 nm show four emission bands at F-5(2) (477 nm), F-5(3) (495 nm),F-5(4) +F-5(2)(545 nm) and5F5 (659 nm) from 5I8-levels. Judd-Ofelt (J-O) theory is used to investigate the J-O intensity parameters, transition probability, stimulated emission cross section and branching ratio. From the results it's perceived that the radiative transition probability and branching ratio values are higher for F-5(4) -> I-5(8) transition as compared to the other transitions.
查看更多>>摘要：The efficient operation of the solar photovoltaic (PV) system is influenced by the accurate determination of its model parameters. The appropriate selection of these parameters is a challenging task due to the multi-modality and non-linearity of the problem. Given less sensitivity to initial solutions and the powerful search capability, many metaheuristic algorithms have been successfully applied to estimate the unknown parameters of PV cell/module models. However, most used techniques are time-consuming, control parameters tuning, etc. This paper proposes an improved Rao-1 (IRao-1) algorithm for efficiently and accurately extracting the PV system parameters. IRao-1 is a new variant of the Rao-1 algorithm, which improves the global search ability of the Rao-1 algorithm by implementing three new search equations. The modification introduced in Rao-1 does not affect its structural simplicity. The effectiveness of the proposed algorithm is evaluated using several PV models, including PV cells (single diode and double diode) and three PV modules. Experimental results demonstrate the superiority of IRao-1 in study cases in terms of efficiency and accuracy by comparing it with recent works.
查看更多>>摘要：The effects of photon inertia on the determination of its trajectory were verified and the representation of a displacement mass characterized by the flow of the number of wavefronts and the decomposition of photon inertia into parts associated with translation and rotation motions was considered. It was found that with the relativistic increase of the photon's resistance to change its directional properties, it inhibits the relativistic trajectory of the second torque, so called Minkowski torque, in an angular range of incidence. After synchronizations, in the OAM inversions, there are reductions of the inertia associated to the translational part that assumes classical predominance, where the relativistic trajectory is allowed while the photon offers less resistance to changes in its directional properties. The classical-relativistic variability of the photon inertia characterizes the classical or relativistic profile of the energy distribution in forms of motion, where adjustments of the rotational and translational parts can be performed as a function of the refractive index rate, temperature and angle of incidence. It was found that with increasing temperature of the refringent medium, the synchronizations displacement in the sense of the normal incidence. A specific vacuum temperature for the refringent medium was characterized, where the photon exhibits a classical-relativistic synchronization under all angles of incidence, characteristic of its immaterial state in vacuum.
查看更多>>摘要：The absorption and extinction efficiencies of a sphere covered by InSb coating and illuminated by an incident plane wave in the terahertz gap were computed. Numerical results shows that these efficiencies, for some core materials and in some spectral regimes, can be reduced by adjusting the temperature. This, reduction of absorption and extinction by the InSb coating is not possible for air and metallic spheres, but it is possible for dielectric spheres. Furthermore, the InSb coating is more effective in absorption reduction for more dissipative dielectric materials, whereas it is more effective in extinction reduction for less dissipative dielectric materials.
查看更多>>摘要：Due to the insufficient expression of uncertain information in fuzzy sets, the fuzzy C-means clustering algorithm is difficult to deal with clustered boundary and outliers. Therefore, this paper proposes a color image segmentation method based on neutrosophic C-means clustering. First, we improved the simple linear clustering algorithm to obtain accurate and natural adaptive local spatial neighborhoods. Secondly, local neighborhood information is added to the objective function of neutrosophic C-means clustering to obtain a more accurate membership. According to the membership, superpixels are divided into certainty group and uncertainty group. Finally, the certainty group is classified by the maximum membership, and the superpixels of the uncertain group are classified by the structural similarity. Experimental results show that the proposed method has better performance on clean and noise images.
查看更多>>摘要：The advent of the quadratic-phase Fourier transform (QPFT) is one of the contemporary developments in the context of integral transforms. This article focuses on an interplay between the well-known Zak transform and the QPFT. To begin with, we formulate the Zak transform in quadratic-phase Fourier domain, braced with an example. In addition, we establish a novel convolution structure in the context of quadratic-phase Zak transform and obtain the corresponding convolution theorem. Finally, we study the Weyl-Heisenberg frames associated with the Quadratic-phase Zak Transform.
查看更多>>摘要：A bulk Nd:LaCa4O(BO3)(3) (Nd:LaCOB) single crystal with the low Nd3+-doping concentration (-0.5 at%) was grown by Czochralski (Cz) method. Its powder X-ray diffraction, Nd3+ ions doping concentration, polarized transmittance and emission spectra, and fluorescence lifetimes were tested. Based on the Judd-Ofelt theory, the spectral parameters of Nd:LaCOB (Nd3+,-0.5 at %) crystals including polarized absorption and emission cross sections, spontaneous transition probability, fluorescence branching ratio, theoretical fluorescence lifetime and intensity parameters (omega(2), omega(4) and omega(6)) were systemically investigated. The calculated radiation lifetimes were compared with the experimental values, resulting in a quantum yield of 33%, which was the highest record among all the Nd:ReCOB (Re: Y, Gd, La1- xGdx) type crystals. The spectral properties of Nd:LaCOB were found to be better than those of Nd:YCOB and Nd:GdCOB crystals, especially in polarized absorption and emission cross sections. The self-frequency-doubling (SFD) angles were calculated according to the main fluorescence peaks of Nd:LaCOB (Nd3+,-0.5 at%) crystals such as 1041 nm, 1060 nm, 1090 nm and 1102 nm, which would be excited and frequency doubled into blue-green, green, yellow-green and yellow lasers. All the results showed that the Nd:LaCOB crystals had potential applications in the field of laser and SFD.
NSTL
Elsevier