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Solar-blind ultraviolet photodetector based on Nb 2C/ β-Ga 2O 3heterojunction. NANOTECHNOLOGY 2024; 35:165502. [PMID: 38150735 DOI: 10.1088/1361-6528/ad18e7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/27/2023] [Indexed: 12/29/2023]
Abstract
β-Ga2O3has been widely investigated for its stability and thermochemical properties. However, the preparation ofβ-Ga2O3thin films requires complex growth techniques and high growth temperatures, and this has hindered the application ofβ-Ga2O3thin films. In this study,β-Ga2O3thin films with good crystalline quality were prepared using a green method, and an ultraviolet (UV) detector based onβ-Ga2O3with a photocurrent of 2.54 × 10-6A and a dark current of 1.19 × 10-8A has been developed. Two-dimensional materials have become premium materials for applications in optoelectronic devices due to their high conductivity. Here, we use the suitable energy band structure between Nb2C and Ga2O3to create a high carrier migration barrier, which reduces the dark current of the device by an order of magnitude. In addition, the device exhibits solar-blind detection, high responsiveness (28 A W-1) and good stability. Thus, the Nb2C/β-Ga2O3heterojunction is expected to be one of the promising devices in the field of UV photoelectric detection.
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Sol-Gel Synthesized Amorphous (In xGa 1-x) 2O 3 for UV Photodetection with High Responsivity. SENSORS (BASEL, SWITZERLAND) 2024; 24:787. [PMID: 38339504 PMCID: PMC10857313 DOI: 10.3390/s24030787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/13/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024]
Abstract
β-Ga2O3 photodetectors have the advantages of low dark current and strong radiation resistance in UV detection. However, the limited photocurrent has restricted their applications. Herein, MSM UV photodetectors based on (InxGa1-x)2O3 (x = 0, 0.1, 0.2, 0.3) by a sol-gel method were fabricated and studied. The doping of indium ions in Ga2O3 leads to lattice distortion and promotes the formation of oxygen vacancies. The oxygen vacancies in (InxGa1-x)2O3 can be modulated by various proportions of indium, and the increased oxygen vacancies contribute to the enhancement of electron concentration. The results show that the amorphous In0.4Ga1.6O3 photodetector exhibited improved performances, including a high light-to-dark current ratio (2.8 × 103) and high responsivity (739.2 A/W). This work provides a promising semiconductor material In0.4Ga1.6O3 for high-performance MSM UV photodetectors.
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Phase-Controlled Tunable Unconventional Photon Blockade in a Single-Atom-Cavity System. MICROMACHINES 2023; 14:2123. [PMID: 38004980 PMCID: PMC10673575 DOI: 10.3390/mi14112123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/07/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023]
Abstract
In the past few years, cavity optomechanical systems have received extensive attention and research and have achieved rapid development both theoretically and experimentally. The systems play an important role in many fields, such as quantum information processing, optomechanical storage, high-precision measurement, macroscopic entanglement, ultrasensitive sensors and so on. Photon manipulation has always been one of the key tasks in quantum information science and technology. Photon blockade is an important way to realize single photon sources and plays an important role in the field of quantum information. Due to the nonlinear coupling of the optical force system, the energy level is not harmonic, resulting in a photon blockade effect. In this paper, we study the phase-controlled tunable unconventional photon blockade in a single-atom-cavity system, and the second-order nonlinear crystals are attached to the cavity. The cavity interacts with squeezed light, which results in a nonlinear process. The system is driven by a complex pulsed laser, and the strength of the coherent driving contains the phase. We want to study the effect of squeezed light and phase. We use the second-order correlation function to numerically and theoretically analyze the photon blockade effect. We show that quantum interference of two-photon excitation between three different transition pathways can cause a photon blockade effect. When there is no squeezed light, the interference pathways becomes two, but there are still photon blockade effects. We explore the influence of the tunable phase and second-order nonlinear strength on the photon blockade effect. We calculate the correlation function and compare the numerical results with the analytical results under certain parameters and find that the agreement is better.
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A High-Performance UVA Photodetector Based on Polycrystalline Perovskite MAPbCl 3/TiO 2 Nanorods Heterojunctions. SENSORS (BASEL, SWITZERLAND) 2023; 23:6726. [PMID: 37571510 PMCID: PMC10422543 DOI: 10.3390/s23156726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/17/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023]
Abstract
The application of TiO2 nanorods in the field of ultraviolet (UV) photodetectors is hindered by a high dark current, which is attributed to crystal surface defects and intrinsic excitation by carrier thermal diffusion. Here, a photodetector based on polycrystalline perovskite MAPbCl3/TiO2 nanorods heterojunctions has been fabricated to overcome the shortcoming. The structure was composed of horizontal MAPbCl3 polycrystalline and vertically aligned TiO2 nanorods array. Many localized depletion regions at the MAPbCl3/TiO2 interface can reduce the dark current. The TiO2/MAPbCl3 detector shows high performance including a high ratio of light-dark current of about six orders of magnitude, which is much larger than that of the TiO2 detector. This study indicates the potential in the TiO2/MAPbCl3 heterojunction to fabricate high-performance UV detectors.
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Using Ligand Engineering to Produce Efficient and Stable Pb-Sn Perovskite Solar Cells with Antioxidative 2D Capping Layers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:14729-14738. [PMID: 35312272 DOI: 10.1021/acsami.1c24763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pb-Sn binary halide perovskites are a promising photovoltaic material due to their low toxicity and optical absorption spectrum well matched to the solar spectrum. However, the ready oxidation of Sn2+ to Sn4+ makes the material system currently too unstable to commercialize. Herein, ligand engineering based on antioxidative tyramine (hydrochloride, TACl) is presented for the first time to increase the stability of this material system. Using this strategy, we generate a two-dimensional (2D) capping layer on top of a standard three-dimensional Pb-Sn film. After capping, the surface defects can be passivated and the TACl-based 2D perovskite effectively protected Sn2+ from oxidation, which stabilized the Sn-Pb perovskite composition, avoiding the Pb-based perovskite formation. It is further found that the TACl treatment suppressed the halide segregation and improved the perovskite film photostability. Cell efficiency increases from 16.25 to 18.28% and device lifetime (T80) increases from less than 100 to over 1000 h. Our finding suggests that tuning ligand form/function represents a potentially highly productive direction to explore when trying to produce stable tin-based perovskite devices.
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Mesoporous Ti 0.5Cr 0.5N for trace H 2S detection with excellent long-term stability. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127193. [PMID: 34844341 DOI: 10.1016/j.jhazmat.2021.127193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Efficient, accurate and reliable detection and monitoring of H2S is of significance in a wide range of areas: industrial production, medical diagnosis, environmental monitoring, and health screening. However the rapid corrosion of commercial platinum-on-carbon (Pt/C) sensing electrodes in the presence of H2S presents a fundamental challenge for fuel cell gas sensors. Herein we report a solution to the issue through the design of a sensing electrode, which is based on Pt supported on mesoporous titanium chromium nitrides (Pt/Ti0.5Cr0.5N). Its desirable characteristics are due to its high electrochemical stability and strong metal-support interactions. The Pt/Ti0.5Cr0.5N-based sensors exhibit a much smaller attenuation (1.3%) in response to H2S than Pt/C-sensor (40%), after 2 months sensing test. Furthermore, the Pt/Ti0.5Cr0.5N-based sensors exhibit negligible cross response to other interfering gases compared with hydrogen sulfide. Results of density functional theory calculation also verify the excellent long-term stability and selectivity of the gas sensor. Our work hence points to a new sensing electrode system that offers a combination of high performance and stability for fuel-cell gas sensors.
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Deep Learning Using Havrda-Charvat Entropy for Classification of Pulmonary Optical Endomicroscopy. Ing Rech Biomed 2021. [DOI: 10.1016/j.irbm.2021.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Correction to "Molecular Doping Inhibits Charge Trapping in Low-Temperature Processed ZnO Towards Flexible Organic Solar Cells". ACS APPLIED MATERIALS & INTERFACES 2021; 13:36654. [PMID: 34297544 DOI: 10.1021/acsami.1c12343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
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10
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Molecular Doping Inhibits Charge Trapping in Low-Temperature-Processed ZnO toward Flexible Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:14423-14432. [PMID: 33733730 DOI: 10.1021/acsami.0c23087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
There has been a growing interest in the development of efficient flexible organic solar cells (OSCs) due to their unique capacity to provide energy sources for flexible electronics. To this end, it is required to design a compatible interlayer with low processing temperature and high electronic quality. In this work, we present that the electronic quality of the ZnO interlayer fabricated from a low-temperature (130 °C) sol-gel method can be significantly improved by doping an organic small molecule, TPT-S. The doped TPT-S, on the one hand, passivates uncoordinated Zn-related defects by forming N-Zn bonds. On the other hand, photoinduced charge transfer from TPT-S to ZnO is confirmed, which further fills up electron-deficient trap states. This renders ZnO improved electron transport capability and reduced charge recombination. By illuminating devices with square light pulses of varying intensities, we also reveal that an unfavorable charge trapping/detrapping process observed in low-temperature-processed devices is significantly inhibited after TPT-S doping. OSCs based on PBDB-T-2F:IT-4F with ZnO:TPT-S being the cathode interlayer yield efficiencies of 12.62 and 11.33% on rigid and flexible substrates, respectively. These observations convey the practicality of such hybrid ZnO in high-performance flexible devices.
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Transcriptomic Alterations Induced By Vemurafenib after Treatment of Melanoma: A Comprehensive Bioinformatics Analysis. Indian J Pharm Sci 2021. [DOI: 10.36468/pharmaceutical-sciences.spl.351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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12
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Metal-organic frameworks-derived hierarchical ZnO structures as efficient sensing materials for formaldehyde detection. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2019.12.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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The effects of Zr-doping on improving the sensitivity and selectivity of a one-dimensional α-MoO3-based xylene gas sensor. Inorg Chem Front 2020. [DOI: 10.1039/d0qi00019a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
One dimensional Zr-doped α-MoO3 nanobelts were synthesized, and the influence of Zr doping on xylene sensing properties was studied.
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UV detector based on an FTO/TiO 2/MoO 3 heterojunction with a potential well trapping electrons in the dark. NANOTECHNOLOGY 2019; 30:465501. [PMID: 31370044 DOI: 10.1088/1361-6528/ab379f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An FTO/TiO2/MoO3 based UV detector has been fabricated through the synthesis of TiO2 nanowires (NWs) on FTO using the hydrothermal method, the preparation of MoO3 on TiO2 NWs by the spin-coating method, after the hydrothermal synthesis, and the preparation of Ag electrodes on the FTO and MoO3. The detector exhibits an excellent performance of photo-to-dark current ratio of more than two orders of magnitude. This performance is produced because the dark current under 2.2 V bias has been significantly inhibited due to the electronic potential well formed by the energy band distribution while the photocurrent has increased in comparison with FTO/TiO2 based detectors under the same conditions which also have a higher photo-to-dark current ratio without the MoO3 content. Not only does this study take advantage of 1D NWs and 2D nanostructures, but it also provides a new way to inhibit the dark current of detectors.
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Excellent Gas Sensing of CdS Nanowires Decorated with Ag Nanoparticles. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2019; 19:7083-7088. [PMID: 31039861 DOI: 10.1166/jnn.2019.16720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this study, CdS nanowires (NWs)/Ag nanoparticle materials (CdS@Ag) with Schottky junction were synthesized by a simple process. The Ag nanoparticles with a diameter of 3-10 nm were uniformly scattered on the surface of CdS NWs with an average diameter of 30 nm. The gas sensing properties and the effect of Ag content and relative humidity on the ethanol sensing properties of CdS NWs were investigated in detail. When the relative humidity was below 60% RH, the sensor, especially the one based on CdS@Ag0.1, exhibited an enhanced ethanol sensing response and selectivity compared with that of pristine CdS NWs, which was believed that Ag catalyzed the reaction between ionized oxygen species and ethanol. However, excessive Ag content does not mean a higher response and even decreased the response. Also, the stability of CdS NWs and CdS@Ag NWs was also investigated, which were almost stable for four months.
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Built-in electric field promotes photoexcitation separation and depletion of most carriers in TiO 2:C UV detectors. NANOTECHNOLOGY 2019; 30:295502. [PMID: 30947163 DOI: 10.1088/1361-6528/ab15f0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
TiO2 has been widely used in ultraviolet (UV) photodetectors, but due to the large number of structural defects and strong band-to-band recombination of the exciton in TiO2, the devices usually have large dark current (I d) and low light current (I l), which seriously reduces the sensitivity and responsivity (R) of the TiO2 based devices. In this work, carbon (C) quantum dots (QDs) are introduced into TiO2 film to ameliorate these issues. Due to the difference of work function between TiO2 nanoparticles and C QDs, the built-in electric field (E bi) can be formed, which effectively facilitates the photogenerated exciton dissociation in the TiO2 film under UV illumination. Meanwhile, the constructed depletion region in dark reduces the majority carrier density, thus decreasing the I d of the photodetector. Moreover, the E bi and depletion region will also contribute to the faster charge collection under UV illumination and recombination of the electron in dark, which is beneficial for the improved response/recovery speed of the device.
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Hierarchical Co 3O 4@NiMoO 4 core-shell nanowires for chemiresistive sensing of xylene vapor. Mikrochim Acta 2019; 186:222. [PMID: 30847573 DOI: 10.1007/s00604-019-3335-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 02/23/2019] [Indexed: 12/15/2022]
Abstract
Hierarchical Co3O4@NiMoO4 core-shell nanowires (NWs) were synthesized utilizing a two-step hydrothermal method. The NWs show a high chemiresistive response (at a temperature of 255 °C) to xylene, with an Rgas/Rair ratio of 24.6 at 100 ppm xylene, while the response towards toluene, benzene, ethanol, and acetone, CO, H2S and NO2 is much weaker. In contrast, pure Co3O4 nanowires exhibit weak responses to all the vapors/gases and poor selectivity. The new NW sensor displays an almost linear response (1-100 ppm) to xylene and a lower detection limit of 424 ppb. The remarkable gas sensing characteristics are attributed to the synergistic catalytic effect and the formation of a heterostructure between Co3O4 and NiMoO4. Graphical abstract Schematic presentation of a xylene vapor chemiresistive sensor based on Co3O4@NiMoO4 core-shell nanowires. The Co3O4@NiMoO4 core-shell nanowires-based sensor exhibits a high response (24.6) to 100 ppm xylene at 255 °C and high response/recovery speed (13-15 and 25-29 s).
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Synthesis of CuO–CdS composite nanowires and their ultrasensitive ethanol sensing properties. Inorg Chem Front 2019. [DOI: 10.1039/c8qi00951a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One dimension CuO/CdS composites with an average diameter of 30 nm were synthesized by a solvothermal method. The operating temperature of the sensors is 182 °C, and their responses were improved by 6 times. The ultrafast response–recovery time was obtained.
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A PFTBT modified visible-blind ultraviolet photodetector with a narrow detecting range and high responsivity. NANOTECHNOLOGY 2018; 29:465501. [PMID: 30160243 DOI: 10.1088/1361-6528/aaddc4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A visible-blind ultraviolet (UV) photodetector (PD) based on TiO2/polyvinyl carbazole doped with poly {[2,7-(9-(20-ethylhexyl)-9-hexyl-fluorene])-alt-[5,50-(40,70-di-2-thienyl-20,10,30-benzothid-iazole)]} (PFTBT) was successfully fabricated. The introduced PFTBT exhibits high absorbance in the UV region and high conductivity which increases the device absorbance and the efficiency of carrier mobility. Besides, PFTBT acts as traps which can increase the concentration of the majority carrier. Therefore, the doped device exhibits high responsivity and high specific detectivity with the value of 0.22 A W-1 and 1.78 × 1012 Jones which respectively has a 3.6 and 2.6 times greater enhancement than the device without doping. The response time is also improved from 27 ms to 22 ms. Owing to the different absorbances that the materials have, the PD has a narrow detection range from 320 nm to 340 nm which is helpful to the study of the specific wavelength. In other words, the research provides a potential way to fabricate practical high-performance UVPDs.
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Analysis of pathogenicity and immune efficacy of fowl adenovirus serotype 4 isolates. Poult Sci 2018; 97:2647-2653. [DOI: 10.3382/ps/pey113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/09/2018] [Indexed: 11/20/2022] Open
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Coordination Polymer-Derived Multishelled Mixed Ni-Co Oxide Microspheres for Robust and Selective Detection of Xylene. ACS APPLIED MATERIALS & INTERFACES 2018; 10:15314-15321. [PMID: 29652469 DOI: 10.1021/acsami.8b03487] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Multishell, stable, porous metal-oxide microspheres (Ni-Co oxides, Co3O4 and NiO) have been synthesized through the amorphous coordination polymer-based self-templated method. Both oxides of Ni and Co show poor selectivity to xylene, but the composite phase has substantial selectivity (e.g., Sxylene/ Sethanol = 2.69) and remarkable sensitivity (11.5-5 ppm xylene at 255 °C). The short response and recovery times (6 and 9 s), excellent humidity-resistance performance (with coefficient of variation = 11.4%), good cyclability, and long-term stability (sensitivity attenuation of ∼9.5% after 30 days and stable sensitivity thereafter) all show that this composite is a competitive solution to the problem of xylene sensing. The sensing performances are evidently due to the high specific surface area and the nano-heterostructure in the composite phase.
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Facilitated extrinsic majority carrier depletion and photogenerated exciton dissociation in an annealing-free ZnO:C photodetector. NANOSCALE 2018; 10:6459-6466. [PMID: 29565440 DOI: 10.1039/c8nr00214b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Applications of ZnO in photodetectors are limited by the great quantity of extrinsic majority carriers due to structural defects and difficult exciton dissociation due to the large exciton binding energy; these generally lead to a higher dark current (Id) and lower light current (Il), severely degrading the responsivity and detectivity. C dots are incorporated into an annealing-free ZnO layer to innovatively construct a local built-in electric field (Ebi) using the difference in the work functions; this simultaneously overcomes the drawbacks of the pristine ZnO photosensitive layer. In dark, the extrinsic majority carrier of ZnO is depleted around the incorporated C dots due to the self-depleting effect; thus, the Id decreases. Under UV illumination, the photogenerated exciton driven by the local Ebi is easily dissociated into a free charge carrier, contributing to the improved Il. This study paves a universal way to effectively improve the detection characteristics of photoconductive devices by incorporating the local Ebi.
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A Sensor Based on LiCl/NaA Zeolite Composites for Effective Humidity Sensing. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2018; 18:1882-1886. [PMID: 29448676 DOI: 10.1166/jnn.2018.14231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
LiCl/NaA zeolite composites were successfully prepared by doping 1 wt%, 2 wt%, 5 wt%, and 8 wt% of LiCl into NaA zeolite. The humidity sensing properties of LiCl/NaA composites were investigated among 11% 95% relative humidity (RH). The LiCl/NaA composites exhibited better humidity sensing properties than pure NaA zeolite. The sensor made by 2 wt% Li-doped NaA zeolite possesses the best linearly in the whole RH. These results demonstrate that the LiCl/NaA composites have the potential application in humidity sensing.
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Alcohol use and alcohol-associated dysbiosis increase susceptibility to pneumococcal pneumonia in a humanized murine HIV model. Alcohol 2018. [DOI: 10.1016/j.alcohol.2017.11.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Porous silver-functionalized ZnSnO3 hollow nanocubes as a gas sensor with an ultra-fast response and recovery speed for acetone detection.
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Orienting the Microstructure Evolution of Copper Phthalocyanine as an Anode Interlayer in Inverted Polymer Solar Cells for High Performance. ACS APPLIED MATERIALS & INTERFACES 2017; 9:32044-32053. [PMID: 28836429 DOI: 10.1021/acsami.7b04947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recent advances in the interfacial modification of inverted-type polymer solar cells (PSCs) have resulted from controlling the surface energy of the cathode-modified layer (TiO2 or ZnO) to enhance the short-circuit current (Jsc) or optimizing the contact morphology of the cathode (indium tin oxide or fluorine-doped tin oxide) and active layer to increase the fill factor. Herein, we report that the performance enhancement of PSCs is achieved by incorporating a donor macromolecule copper phthalocyanine (CuPc) as an anode modification layer. Using the approach based on orienting the microstructure evolution, uniformly dispersed island-shaped CuPc spot accumulations are built on the top of PTB7:PC71BM blend film, leading to an efficient spectral absorption and photogenerated exciton splitting. The best power conversion efficiency of PSCs is increased up to 9.726%. In addition to the enhanced light absorption, the tailored anode energy level alignment and optimized boundary morphology by incorporating the CuPc interlayer boost charge extraction efficiency and suppress the interfacial molecular recombination. These results demonstrate that surface morphology induction through molecular deposition is an effective method to improve the performance of PSCs, which reveals the potential implications of the interlayer between the organic active layer and the electrode buffer layer.
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Cumulative live-birth rate with repeat in vitro fertilization treatment cycles of chinese advanced age women. Fertil Steril 2017. [DOI: 10.1016/j.fertnstert.2017.07.1007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Organics filled one-dimensional TiO 2 nanowires array ultraviolet detector with enhanced photo-conductivity and dark-resistivity. NANOSCALE 2017; 9:9095-9103. [PMID: 28643838 DOI: 10.1039/c7nr03408c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A heterojunction photo-conductive ultraviolet (UV) detector was developed based on TiO2 nanowires array (NWA) surrounded by N,N'-bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1'-biphenyl)-4,4'-diamine (NPB). The novel and effective two-step method of static infusion and dynamic solution-cleaning was employed to fill NPB into TiO2 NWA gaps and simultaneously remove the unwelcomed top NPB layer. The device fabricated via the two-step method exhibited optimal performance compared to TiO2/NPB device with top NPB layer and TiO2 NWA device. In dark conditions, the TiO2/NPB heterojunction device without top NPB was found to possess the capacity of depleting majority carriers, thereby providing improved dark-resistivity to limit the dark current (Id). Under UV illumination, the depleting effect could be eliminated by the dissociation and accumulation of photo-generated carriers between pn heterojunction, leading to increased carrier density and photo-conductivity. It cleared up the high barrier due to the removal of top NPB layer, which was beneficial for hot electron transport than the device with top NPB layer under illumination, thereby achieving an enhanced light current (Il) to Id ratio of 1.67 × 104. A simple technology is provided to prepare organic-inorganic hybrid one-dimensional array heterostructure, which plays a remarkable role in the working of the UV detector, enhancing photo-conductivity and dark-resistivity of the device.
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Decreased Charge Transport Barrier and Recombination of Organic Solar Cells by Constructing Interfacial Nanojunction with Annealing-Free ZnO and Al Layers. ACS APPLIED MATERIALS & INTERFACES 2017; 9:22068-22075. [PMID: 28605909 DOI: 10.1021/acsami.7b06235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To overcome drawbacks of the electron transport layer, such as complex surface defects and unmatched energy levels, we successfully employed a smart semiconductor-metal interfacial nanojunciton in organic solar cells by evaporating an ultrathin Al interlayer onto annealing-free ZnO electron transport layer, resulting in a high fill factor of 73.68% and power conversion efficiency of 9.81%. The construction of ZnO-Al nanojunction could effectively fill the surface defects of ZnO and reduce its work function because of the electron transfer from Al to ZnO by Fermi level equilibrium. The filling of surface defects decreased the interfacial carrier recombination in midgap trap states. The reduced surface work function of ZnO-Al remodulated the interfacial characteristics between ZnO and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM), decreasing or even eliminating the interfacial barrier against the electron transport, which is beneficial to improve the electron extraction capacity. The filled surface defects and reduced interfacial barrier were realistically observed by photoluminescence measurements of ZnO film and the performance of electron injection devices, respectively. This work provides a simple and effective method to simultaneously solve the problems of surface defects and unmatched energy level for the annealing-free ZnO or other metal oxide semiconductors, paving a way for the future popularization in photovoltaic devices.
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SEGMENTATION OF ORGANS AT RISK IN THORACIC CT IMAGES USING A SHARPMASK ARCHITECTURE AND CONDITIONAL RANDOM FIELDS. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2017; 2017:1003-1006. [PMID: 29062466 PMCID: PMC5649634 DOI: 10.1109/isbi.2017.7950685] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cancer is one of the leading causes of death worldwide. Radiotherapy is a standard treatment for this condition and the first step of the radiotherapy process is to identify the target volumes to be targeted and the healthy organs at risk (OAR) to be protected. Unlike previous methods for automatic segmentation of OAR that typically use local information and individually segment each OAR, in this paper, we propose a deep learning framework for the joint segmentation of OAR in CT images of the thorax, specifically the heart, esophagus, trachea and the aorta. Making use of Fully Convolutional Networks (FCN), we present several extensions that improve the performance, including a new architecture that allows to use low level features with high level information, effectively combining local and global information for improving the localization accuracy. Finally, by using Conditional Random Fields (specifically the CRF as Recurrent Neural Network model), we are able to account for relationships between the organs to further improve the segmentation results. Experiments demonstrate competitive performance on a dataset of 30 CT scans.
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Boosted Electron Transport and Enlarged Built-In Potential by Eliminating the Interface Barrier in Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2017; 9:8830-8837. [PMID: 28233487 DOI: 10.1021/acsami.6b15631] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A smart interface modification strategy was employed to simultaneously improve short-circuit current density (Jsc) and open-circuit voltage (Voc) by incorporating a poly[(9,9-bis(3'-(N,N-dimethylamion)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl)-fluorene] (PFN) interlayer between a TiO2 film and an active layer, arising from the fact that PFN effectively eliminated the interface barrier between TiO2 and the fullerene acceptor. The work function (WF) of TiO2 was apparently reduced, which facilitated effective electron transfer from the active layer to the TiO2 electron transport layer (ETL) and suppressed charge carrier recombination between contact interfaces. Electron injection devices with and without a PFN interlayer were fabricated to prove the eliminated electron barrier, meanwhile photoluminescence (PL) and time-resolved transient photoluminescence (TRTPL) were measured to probe much easier electron transfer from [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) acceptor to TiO2 ETL, contributing to enhanced Jsc. The shift in vacuum level altered the WF of PC71BM, which enlarged the internal electrical field at the donor/acceptor interface and built-in potential (Vbi) across the device. Dark current characteristics and Mott-Schottky measurements indicated the enhancement of Vbi, benefiting to increased Voc. Consequently, the champion power conversion efficiency for a device with a PFN interlayer of 0.50 mg/mL reached to 7.14%, which is much higher than the PCE of 5.76% for the control device.
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Intérêt des séquences avancées en IRM dans l’évaluation à la réponse au Bevacizumab. Suivi multimodal de 20 glioblastomes. J Neuroradiol 2017. [DOI: 10.1016/j.neurad.2017.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Importance des variations spectrales durant 36 mois de suivi longitudinal IRM et SRM de 80 patients atteints de glioblastomes traités. J Neuroradiol 2017. [DOI: 10.1016/j.neurad.2017.01.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Improving the charge carrier transport of organic solar cells by incorporating a deep energy level molecule. Phys Chem Chem Phys 2017; 19:245-250. [DOI: 10.1039/c6cp07344a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A p-type F4-TCNQ molecule was incorporated into the P3HT/ICBA active layer to enhance the device performance of polymer solar cells from 4.50% to 5.83%.
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Interface passivation and electron transport improvement of polymer solar cells through embedding a polyfluorene layer. Phys Chem Chem Phys 2017; 19:15207-15214. [DOI: 10.1039/c7cp01326d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The TiO2 cathode interface layer modified by a polyfluorene interlayer results in a considerable effect on polymer solar cells.
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Employing inorganic/organic hybrid interface layer to improve electron transfer for inverted polymer solar cells. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.06.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Research of dual-band microwave photonic filter for WLAN based on optical frequency comb. APPLIED OPTICS 2016; 55:5520-5525. [PMID: 27463899 DOI: 10.1364/ao.55.005520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper presents a dual-band microwave photonic filter for a wireless local area networks with independently tunable passband center frequencies and bandwidths. The two bands of the filter were 2.4 GHz and 5.725 GHz, respectively. The filter was based on a stimulated Brillouin scattering and an optical frequency comb (OFC) scheme. We created this filter using OFC pumps instead of a single pump. The OFC scheme consists of a cascaded Mach-Zehnder modulator (MZM) and a dual-parallel MZM (DPMZM) hybrid modulation that generated seven and 11 lines. The experimental results show that the two passbands of the filter were 80 and 130 MHz.
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TU-AB-202-11: Tumor Segmentation by Fusion of Multi-Tracer PET Images Using Copula Based Statistical Methods. Med Phys 2016. [DOI: 10.1118/1.4957433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Performance Improvement of Polymer Solar Cells by Surface-Energy-Induced Dual Plasmon Resonance. ACS APPLIED MATERIALS & INTERFACES 2016; 8:6183-6189. [PMID: 26900763 DOI: 10.1021/acsami.6b00297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The surface plasmon resonance (SPR) effect of metal nanoparticles (MNPs) is effectively applied on polymer solar cells (PSCs) to improve power conversion efficiency (PCE). However, universality of the reported results mainly focused on utilizing single type of MNPs to enhance light absorption only in specific narrow wavelength range. Herein, a surface-energy-induced dual MNP plasmon resonance by thermally evaporating method was presented to achieve the absorption enhancement in wider range. The differences of surface energy between silver (Ag), gold (Au), and tungsten trioxide (WO3) compared by contact angle images enable Ag and Au prefer to respectively aggregate into isolated islands rather than films at the initial stage of the evaporation process, which was clearly demonstrated in the atomic force microscopy (AFM) measurement. The sum of plasmon-enhanced wavelength range induced by both Ag NPs (350-450 nm) and Au NPs (450-600 nm) almost cover the whole absorption spectra of active layers, which compatibly contribute a significant efficiency improvement from 4.57 ± 0.16 to 6.55 ± 0.12% compared to the one without MNPs. Besides, steady state photoluminescence (PL) measurements provide strong evidence that the SPR induced by the Ag-Au NPs increase the intensity of light absorption. Finally, ultraviolet photoelectron spectroscopy (UPS) reveals that doping Au and Ag causes upper shift of both the work function and valence band of WO3, which is directly related to hole collection ability. We believe the surface-energy-induced dual plasmon resonance enhancement by simple thermally evaporating technique might pave the way toward higher-efficiency PSCs.
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Enhanced Electron Extraction Capability of Polymer Solar Cells via Employing Electrostatically Self-Assembled Molecule on Cathode Interfacial Layer. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8224-8231. [PMID: 26955888 DOI: 10.1021/acsami.5b12394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this paper, high-performance inverted polymer solar cells (PSCs) with a modified cathode buffer layer, titanium dioxide:polyethylenimine (TiO2:PEI), are demonstrated. The TiO2-O-PEI transport layer was fabricated by electrostatically self-assembled monolayers (ESAM) of PEI molecules. Protonated amine functional groups of PEI can combine protons (H(+)) hydrolyzing from its aqueous solution. Also, PEI could produce ESAM on the surface of hydroxylated TiO2 because of its cationic characteristics. The incorporation of the TiO2-O-PEI layer enhances the photocurrent and power conversion efficiency (PCE) due to the improved interfacial electron transport and extraction of the TiO2-O-PEI surface and the increased light absorption of the active layer. The enhanced PCE, low-cost materials, and solution process of TiO2-O-PEI buffer layers provide a promising method for highly efficient PSCs.
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Special Issue on Medical Image Analysis for Computer Aided Diagnosis. Ing Rech Biomed 2016. [DOI: 10.1016/j.irbm.2016.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Segmentation of lymphoma tumor in PET images using cellular automata: A preliminary study. Ing Rech Biomed 2016. [DOI: 10.1016/j.irbm.2015.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hydrothermal synthesis and enhanced xylene-sensing properties of pompon-like Cr-doped Co3O4hierarchical nanostructures. RSC Adv 2016. [DOI: 10.1039/c5ra26466a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Unique pompon-like Cr-doped Co3O4hierarchical nanostructures were preparedviaa hydrothermal method, showing extraordinary sensing properties towards xylene.
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An organosilane self-assembled monolayer incorporated into polymer solar cells enabling interfacial coherence to improve charge transport. Phys Chem Chem Phys 2016; 18:16005-12. [DOI: 10.1039/c6cp02722a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An organosilane self-assembled monolayer is introduced onto a TiO2transporting layer to improve electron extraction for polymer solar cells.
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Abstract
Pure and Fe-doped MoO3 nanobelts were synthesized by a facile one-step hydrothermal method and their xylene-sensing properties were investigated.
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Performance enhancement of organic photovoltaic devices enabled by Au nanoarrows inducing surface plasmonic resonance effect. Phys Chem Chem Phys 2016; 18:24285-9. [DOI: 10.1039/c6cp04302j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The significant performance enhancement of organic photovoltaic devices was achieved upon incorporating Au nanoarrows in a ZnO buffer layer.
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A model for the coupling of the Greater Bairam and local environmental factors in promoting Rift-Valley Fever epizootics in Egypt. Public Health 2016; 130:64-71. [PMID: 26298586 PMCID: PMC4718900 DOI: 10.1016/j.puhe.2015.07.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 04/13/2015] [Accepted: 07/09/2015] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Rift-Valley Fever (RVF) is a zoonotic mosquito-borne disease in Africa and the Arabian Peninsula. Drivers for this disease vary by region and are not well understood for North African countries such as Egypt. A deeper understanding of RVF risk factors would inform disease management policies. STUDY DESIGN The present study employs mathematical and computational modeling techniques to ascertain the extent to which the severity of RVF epizootics in Egypt differs depending on the interaction between imported ruminant and environmentally-constrained mosquito populations. METHODS An ordinary differential system of equations, a numerical model, and an individual-based model (IBM) were constructed to represent RVF disease dynamics between localized mosquitoes and ruminants being imported into Egypt for the Greater Bairam. Four cases, corresponding to the Greater Bairam's occurrence during distinct quarters of the solar year, were set up in both models to assess whether the different season-associated mosquito populations present during the Greater Bairam resulted in RVF epizootics of variable magnitudes. RESULTS The numerical model and the IBM produced nearly identical results: ruminant and mosquito population plots for both models were similar in shape and magnitude for all four cases. In both models, all four cases differed in the severity of their corresponding simulated RVF epizootics. The four cases, ranked by the severity of the simulated RVF epizootics in descending order, correspond with the occurrence of the Greater Bairam on the following months: July, October, April, and January. The numerical model was assessed for sensitivity with respect to parameter values and exhibited a high degree of robustness. CONCLUSIONS Limiting the importation of infected ruminants beginning one month prior to the Greater Bairam festival (on years in which the festival falls between the months of July and October: 2014-2022) might be a feasible way of mitigating future RVF epizootics in Egypt.
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Enhanced electron extraction capability of polymer solar cells via modifying the cathode buffer layer with inorganic quantum dots. Phys Chem Chem Phys 2016; 18:11435-42. [DOI: 10.1039/c6cp00989a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Inorganic quantum dots were employed to modify the electron transporting layer of PSCs, and a great enhancement of PCE was achieved.
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Abstract
CdS nanowires (NWs) with an average diameter of 30 nm were synthesized by a solvothermal method and then Au nanoparticles with a size of 10–25 nm were decorated on the surface of the as-synthesized CdS NWs through a simple deposition process.
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Robust Optimal Feature Selection for Lung Tumor Recurrence Prediction in PET Imaging. Int J Radiat Oncol Biol Phys 2015. [DOI: 10.1016/j.ijrobp.2015.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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