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- 2018
- Plastic rod scintillator
- Radiation interaction position
- Artificial Neural Network
- Position sensitive detector
- Optoelectronic Information Science and Engineering
- University of Qom
- Shahrood University of Technology
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Effect of Auxiliary Donors on 3,8-Phenothiazine Dyes for Dye-Sensitized Solar Cells
摘要： Phenothiazines are one of the more common dye scaffolds for dye-sensitized solar cells. However, these sensitizers are exclusively based on a 3,7-substitution pattern. Herein, we have synthesized and characterized novel 3,8-substituted phenothiazine dyes in order to evaluate the effect of auxiliary donor groups on the performance of this new dye class. The power conversion efficiency increased by 7%–10% upon insertion of an auxiliary donor in position 8 of the phenothiazine, but the structure of the auxiliary donor (phenyl, naphthyl, pyrene) had a low impact when electrodes were stained with chenodeoxycholic acid (CDCA) additive. In the absence of CDCA, the highest power conversion efficiency was seen for the phenyl-based sensitizer attributed to a higher quality dye-monolayer. By comparing the novel dyes to their previously reported 3,7- analogues, only subtle differences were seen in photophysical, electrochemical, and performance measurements. The most notable difference between the two geometries is a lowering of the oxidation potentials of the 3,8-dyes by 40–50 mV compared to the 3,7-analogues. The best auxiliary donor for the 3,8-phenothiazine dyes was found to be pyrenyl, with the best device delivering a power conversion efficiency of 6.23% (99 mW cm?2, 10 eq. CDCA, JSC = 10.20 mA cm?2, VOC = 791 mV, and FF = 0.765).
关键词： Geometry study,auxiliary donor,donor position,phenothiazine,dye-sensitized solar cells
更新于2025-09-12 10:27:22
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Free Space Optical Communication (System Design, Modeling, Characterization and Dealing with Turbulence) || 4. Mitigation of beam wandering due to atmospheric turbulence and prediction of control quality using intelligent decision making tools
摘要： In a Free Space Optical Link (FSOL), atmospheric turbulence causes fluctuations in both intensity and phase of the received beam and impairs link performance. Beam motion is one of the main causes for major power loss. This chapter presents an investigation of the performance of two types of controller designed for aiming a laser beam at a particular spot under dynamic disturbances. Multiple experiment observability nonlinear input-output data mapping is used as the principal component for the controllers’ design. The first design is based on the Taguchi method while the second is the Artificial Neural Network (ANN) method. These controllers process the beam location information from a static linear map of a 2D plane: Optoelectronic Position Detector (OPD) as observer, and then generate the necessary outputs to steer the beam with a micro-electromechanical mirror: Fast Steering Mirror (FSM). The beam centroid is computed using a Mono-Pulse Algorithm (MPA). Evidence of suitability and effectiveness of the proposed controllers are comprehensively assessed and quantitatively measured in terms of coefficients of correlation, correction speed, control exactness, centroid displacement and stability of the receiver signal through the experimental results from the FSO link setup established for the horizontal range of 0.5 km at an altitude of 15.25 m. The test field type is open flat terrain, grass and a few isolated obstacles.
关键词： atmospheric turbulence,Artificial Neural Network (ANN),Mono-Pulse Algorithm (MPA),Fast Steering Mirror (FSM),beam wandering,Taguchi method,Free Space Optical Link (FSOL),Optoelectronic Position Detector (OPD)
更新于2025-09-12 10:27:22
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Position effect of arylamine branches on pyrene-based dopant-free hole transport materials for efficient and stable perovskite solar cells
摘要： In this work, arylamine branches N4-[4-[Bis(4-methoxyphenyl)-amino]phenyl]-N1,N1-bis(4-methoxyphenyl)-1,4-benzenediamine are introduced to the 1,6- and 2,7-positions of pyrene core to afford two novel HTMs coded PYR16 and PYR27. The influence of different positions of arylamine units on the optical and electronic properties and the performance of PSCs are investigated. The perovskite solar cells (PSCs) using dopant-free PYR16 exhibite a PCE of 17.00%, which is higher than that of PYR27 (14.67%). Furthermore, the PSCs based on PYR16 obtain better stability than those using PYR27 by maintaining 98% of the initial values after 1080 h at 80 ℃ in an ambient environment in the dark and 85% of initial values after 672 h under continuous sunlight soaking in an ambient environment at 45-50 ℃.
关键词： perovskite solar cell,position effect,stability,hole transport material,pyrene
更新于2025-09-12 10:27:22
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Position Measurement of Laser Center by Using 2-D PSD and Fixed-Axis Rotating Device
摘要： Photoelectric non-contact measurement methods have been widely implemented in space target location, micro-displacement measurement and space optical communication. In term of the reliability and precision of measurement systems, it is a great significance to obtain the laser center location accurately. Since the two-dimensional position sensitive detector (2-D PSD) can continuously detects the gravity center position of the laser spot on its photosensitive surface, this paper provides a flexible method with high precision for the nonlinear correction of PSD as well as a new idea for PSD-based moving laser center positioning. Above all, a laser device system that rotating around a fixed-axis is designed, and the rotation angle can be controlled with the rotation accuracy of 0.5?. The trace of the gravity center of the rotating spot generated by the device on the PSD surface is detected, and then the laser center location is obtained after further processing of data. In order to improve the detection accuracy of PSD, this research mainly focuses on the nonlinear correction method of the detector and the fitting method of the gravity center trace of the laser spot. Moreover, the effects of different sizes of light spots projected onto the 2-D PSD on the collected photocurrent and estimated coordinates were analyzed by experiments. From the experimental results, the non-linear error of PSD is corrected by the error curved surface interpolation method, the overall error is reduced by more than 32%, and the linearity of the positioning of the laser moving along the diagonal of PSD is 0.2%.
关键词： Position sensitive detector,curve surface fitting,laser center location,rotating laser
更新于2025-09-11 14:15:04
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Brief Introduction to The application of Laser Blanking Line on Automobile Sheets
摘要： Limonium bicolor is a typical exo-recretohalophyte with multi-cellular salt glands. A differential interference contrast (DIC) microscope were applied to investigate the pattern of salt gland distribution in L. bicolor at the individual level. For a single mature leaf, more salt glands are distributed in the leaf central and apical regions than leaf base. For the leaves in different developmental stages, firstly, the density of salt glands linearly decreased at the beginning of leaf expansion and kept a relatively constant value in the later periods, which was mainly due to the rapid expansion of epidermal cells. Secondly, the total number of glands per leaf showed a reversed trend compared to the density of salt glands. These results suggested that the salt gland density was adapted to the leaf age and area as more and more salt accumulated in the saline soils.
关键词： salt glands,leaf position,Limonium bicolor,leaf age,distribution
更新于2025-09-11 14:15:04
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Effects of Monofluorinated Positions at the End-Capping Groups on the Performances of Twisted Non-Fullerene Acceptor-Based Polymer Solar Cells
摘要： Recently, the main-chain twisted small molecules are attractive as electron-acceptors in polymer solar cells (PSCs) for their up-shifted molecular energy levels, enhanced extinction coefficients, better charge extraction properties along with longer carrier lifetime and lower recombination rate relative to their planar analogues, which are conducive to the power conversion efficiency (PCE) promotion of PSCs. To further probe the ‘structure-performance’ correlation of main-chain twisted acceptors, in particular the mono-fluorine substituted sites on the performances of the resultant acceptors, two new main-chain twisted small molecules were synthesized, in which a fluorine atom was introduced at different sites on the end-capping group 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (INCN). Although finely structural modification was adopted, quite different performances were obtained in the two acceptors. Compared to the 3-fluorinated analogue (i-IEICO-F3), the mixture of 4-florinated and 5-fluorinated isomers (i-IEICO-2F) exhibited higher dipole moment, enlarged molar extinction coefficient with bathochromic-shifted absorption region, suppressed charge recombinations with balanced charge mobilities, and slightly enhanced crystallinity. In combination with a fluorobenzotriazole-based medium-bandgap polymer (J52), a high efficiency of 12.86% was resultantly achieved in i-IEICO-2F-based device, which is superior to the result (7.65%) of i-IEICO-F3 device, revealing the importance of mono-fluorinated positions on the performances of main-chain twisted non-fullerene acceptors.
关键词： Power conversion efficiency,Fluorinated position effects,Main-chain twisted small molecular acceptors,Polymer solar cells,Non-fullerene acceptors
更新于2025-09-11 14:15:04
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Mechanism Analysis of PCC Harmonic Resonance Based on Nonlinear Self-Oscillation Concept in a High-Power Grid-Tied Photovoltaic Plant
摘要： Polycrystalline materials can be divided into four types of microstructural components, including grain cell (GC), grain boundary (GB), triple junction (TJ) and vertex points (VP). Nanoindentation at different microstructural components on the polycrystalline materials surface can lead to different plastic deformation behaviors of the polycrystalline materials. Due to experimental limitations, the indentation-induced internal stress and defect evolution process are difficult to investigate directly, especially for the polycrystalline materials with grain size less than 100 nm. The molecular dynamics (MD) simulations were performed to unravel the initial indentation position effect on the elasticity/plastic deformation mechanism of polycrystalline copper. The results reveal that the initial indentation position governs the indentation force variation and defect distribution range due to the different dimensionalities of the microstructural components. The defect propagation as well as the internal stress transmission in the GC regions tend to transfer to the low-dimensional microstructural components of the interfaces. In addition, the atomic internal stress and potential energy accumulation/release of the microstructural component atoms during the nanoindentation process are also investigated, revealing that the atomic internal stress and potential energy in the VPs vary earliest, followed by the TJs, GBs and GCs.
关键词： microstructural component,initial indentation position,molecular dynamics,polycrystalline material,Nanoindentation
更新于2025-09-11 14:15:04
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Stripline beam position monitor for X-ray free electron laser of Pohang Accelerator Laboratory
摘要： Beam position monitors (BPMs) are important instruments even in the case of an X-ray free-electron laser (XFEL). Pohang Accelerator Laboratory (PAL) finished the construction of an XFEL (PAL-XFEL) in 2015, and new stripline BPMs were installed in PAL-XFEL. New BPMs were designed to have a strong signal and a high resolution. In addition, the impedance matching was considered to reduce a signal reflection. These features of the BPM design were confirmed with a simulation study as well. Fabricated BPMs were tested by using a wire test stand. Two-dimensional position errors and offsets were measured to select best BPMs for PAL-XFEL. Finally, a real beam test was tried to check the BPM performance and a better resolution than the requirement was obtained.
关键词： stripline BPM,X-ray free-electron laser,Beam position monitors,impedance matching,PAL-XFEL
更新于2025-09-11 14:15:04
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Feasibility of High-Resolution PET Detector Readout by Two-Dimensional Tetra-Lateral Position-Sensitive Silicon Photomultiplier
摘要： In this paper, we present the feasibility of high-resolution PET detector readout by a two-dimensional (2D) tetra-lateral position-sensitive Silicon photomultiplier with an intrinsic cap resistive layer for charge division (CRL-SiPM). The scintillation imaging sensor for 511keV gamma ray detection is realized by coupling a 5×5 array of 0.45×0.45×6 mm3 LYSO crystals to the CRL-SiPM with an active area of 2.77×2.77 mm2 and micro APD cell pitch of ~10 μm. The scintillator arrays are clearly distinguished and good scintillator array imaging with little position distortion has been achieved. An energy resolution of ~13.5% and coincidence time resolution of 555 ps are demonstrated, respectively. Therefore, the potential PET imaging sensor with greatly reduced readout channels has been verified.
关键词： position sensitive,Silicon photomultiplier,LYSO,Avalanche photodiodes,PET detector
更新于2025-09-11 14:15:04
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A new optical technique to monitor joint motion using position sensitive detector
摘要： BACKGROUND: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient. OBJECTIVE: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time. METHODS: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements. RESULTS: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system. CONCLUSIONS: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science.
关键词： position sensitive detector,Human joint angle,range of motion,optical goniometer,rehabilitation
更新于2025-09-10 09:29:36