- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A novel 1,8-naphthalimide as highly selective naked-eye and ratiometric fluorescent sensor for detection of Hg2+ ions
摘要： A novel colorimetric and ratiometric fluorescent chemosensor, 2-(2-mercaptophenyl)-1H-benzo[de]isoquinoline-1,3-(2H)-dione (L3) is reported for Hg2+ ions. The selective binding of Hg2+ to L3 afforded new absorbance and fluorescence peaks at 438 nm and 480 nm, in addition to the existing bands of L3 at 332 nm and 376 nm. It also showed apparent colour change from colourless to yellowish green and weak fluorescent to bright yellowish green strong fluorescent due to selective binding of Hg2+ ion. The sensor forms a 1:1 stoichiometry with high binding constants (3.89 × 10^4 mol^-1 L) and limit of detection 1.74 × 10^-8 M with high selectivity and sensitivity towards Hg2+ in the presence of other interfering metal ions. More importantly, it has good practicability in environmental water sample. The outcome of photo-physical experiment has also been in good accordance with the time-resolved fluorescence life decays and the density functional theory (DFT) estimations. Moreover, the L3-Hg2+ solution displayed high colorimetric and fluorimetric reversibility via the addition of KI. This reversibility in fluorescence showed potential applicability of chemosensor L3 as 'on–off–on' naked eye sensor.
关键词： Molecular logic gate,Red-shift,DFT,Off–on–off Hg2+ chemosensor,Naked eye detection,Ratiometric fluorescence
更新于2025-09-19 17:15:36
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SnSe2 Field-Effect Transistor with High On/Off Ratio and Polarity-Switchable Photoconductivity
摘要： SnSe2 field-effect transistor was fabricated based on exfoliated few-layered SnSe2 flake, and its electrical and photoelectric properties have been investigated in detail. With the help of a drop of de-ionized (DI) water, the SnSe2 FET can achieve an on/off ratio as high as ~ 104 within 1 V bias, which is ever extremely difficult for SnSe2 due to its ultrahigh carrier density (1018/cm3). Moreover, the subthreshold swing and mobility are both improved to ～ 62 mV/decade and ~ 127 cm2 V?1 s?1 at 300 K, which results from the efficient screening by the liquid dielectric gate. Interestingly, the SnSe2 FET exhibits a gate bias-dependent photoconductivity, in which a competition between the carrier concentration and the mobility under illumination plays a key role in determining the polarity of photoconductivity.
关键词： Photoconductivity,SnSe2,Field-effect transistor,On/off ratio
更新于2025-09-19 17:15:36
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Two-Mode MoS <sub/>2</sub> Filament Transistor with Extremely Low Sub-Threshold Swing and Record High On/Off Ratio
摘要： With rapid development of integrated circuits, urge requirements for transistor with lower sub-threshold swing (SS) and better contact properties, are needed. To optimize the SS and contact issues, we propose a concept of molybdenum disulfide (MoS2) filament transistor with two-mode. We successfully fabricated the proposed devices in a wafer-scale. Mode I can enable the device with extremely low SS down to 2.26 mV/dec by switching contact filament between on and off while mode II can realize record high on/off ratio 2.6×109 by using filament as quasi-zero dimensional (quasi-0D) contact. Compared to conventional three dimensional (3D) contact, quasi-0D contact using conductive filament improves the current density nearly 50 times. We also built spice model to simulate the electrical behaviors and successfully predict proposed transistor owns extremely low SS in mode I (using abrupt filament formation/rupture) and excellent quasi-0D contact in mode II. The two-mode MoS2 filament transistor can significant improve the SS and contact comparing to those of the state-of-the-art transistors, which has the great potential to boost the development of next generation mainstream transistors.
关键词： sub-threshold swing,molybdenum disulfide,quasi-0D contact,filament transistor,on/off ratio
更新于2025-09-19 17:15:36
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Low pressure chemical vapor deposition of In <sub/>2</sub> O <sub/>3</sub> films on off-axis c-sapphire substrates
摘要： Heteroepitaxial In2O3 films were grown on transparent c-sapphire substrates with 0°, 3.5°, 6° and 8° off-axis angles via low pressure chemical vapor deposition (LPCVD). Metallic solid indium and oxygen gas were used as the precursors. X-ray diffraction (XRD) spectroscopy and cross-sectional scanning transmission electron microscopy (STEM) were used to study the effects of substrate off-axis on the crystalline quality of the as-grown films. The XRD 2θ-ω spectra confirmed the growth of body centered cubic bixbyite In2O3 films with (111) out-of-plane orientation. STEM images revealed the suppressed dislocation density in the films grown on substrates with off-axis angles. The crystal structure was further confirmed by Raman spectroscopy. Fifteen peaks corresponding to bcc-In2O3 Raman modes were observed at room temperature (RT). XRD ω-rocking curves, XRD Φ-scan profiles and STEM images indicate improved crystalline quality in films grown on substrates with, particularly, 3.5° and 6° off-cut angles. Growth rates in a wide range of ~ 0.5 - 30 μm/hr were achieved. RT photoluminescence peak at ~2.15 eV is attributed to the deep level defect transitions. RT photoluminescence excitation peak at ~3.38 eV corresponds to the optical bandgap of bcc-In2O3. RT electron Hall mobilities of ~ 88 - 116 cm2/V.s were measured with background carrier concentrations of ~ 6 - 9x1017 cm-3.
关键词： low pressure chemical vapor deposition,Indium oxide,off-axis substrate,c-sapphire
更新于2025-09-19 17:15:36
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[IEEE 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - PANGKAL PINANG, Indonesia (2018.10.2-2018.10.4)] 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - Comparative Analysis of Applications Off-Grid PV System and On-Grid PV System for Households in Indonesia
摘要： In Indonesia, about 89.75% of all power stations use fossil fuels, and only 10.25% generation uses renewable energy, i.e., hydropower generation, geothermal power, solar power and wind power. The use of fossil fuels such as coal, oil, and gas will cause environmental degradation. To help reduce environmental degradation requires the use of renewable energy such as solar energy through power plants in large quantities. In this paper will discuss solar power technically and economically, in this case, the cost of generation per kWh for each solar generating scheme is rooftop Off-grid photovoltaic (PV) system and on-grid PV system. Two schemes were created to calculate the generation cost per kWh for off-grid and grid-connected PV systems based on component prices for several cities in Indonesia. Electricity generation cost per kWh for off-grid PV systems and grid-connected PV system are respectively 4,644 IDR/kWh and 1,244 IDR/kWh compared to PLN electricity tariff is 1,467.28 IDR/kWh.
关键词： off-grid PV system,on-grid PV system,Solar Power Plants
更新于2025-09-19 17:15:36
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Flow-Through Self-Standing Porous Silicon Sensor
摘要： A self-standing porous silicon (PS) multilayer structure detached from the substrate by the lift-off method and integrated with a microfluidic cell is presented. Experiments of refractive index changes sensing flow through open-ended pores are reported. We continuously recorded the reflectance spectra of the PS membrane each 30 s and measured the shift as different substances flowed through the structure. The experimental sensitivity values are in good agreement with the theoretical simulations performed.
关键词： membrane,self-standing film,lift-off,sensing,porous silicon,flow-through
更新于2025-09-19 17:15:36
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Efficient “Ratiometric” fluorescence chemosensor for selective detection of Hg2+ ions based on phosphonates: its live cell imaging and molecular keypad lock applications
摘要： We report that the smart chemosensors (L1 and L2) can detect Hg2+ ion selectively over other metal ions was studied by various spectral techniques. Particularly, the proposed chemosensors exhibiting the notable color and spectra changes with the addition of mercury ions. Moreover, the colorimetric and fluorescence could be reversed with the addition of EDTA into the L1-Hg2+ and L2-Hg2+ solutions. Based on the admirable reversibility process, we displayed a molecular-scale sequential information processing circuit proposed the “Writing-Reading-Erasing-Reading” and “Multi-write” behaviors in the form of binary logic. Furthermore, L1 and L2 mimic as a molecular keypad lock and molecular logic gates with the successive addition of Hg2+ and EDTA. The binding ability of Hg2+ ion with L1 and L2 was further demonstrated by Density Functional Theory (DFT) studies. The biocompatibility of these chemosensors is successfully used for live cell imaging of Hg2+ in HeLa cells under the experimental conditions. Furthermore, the sensors L1 and L2 were also useful to determine the concentration of Hg2+ ion in real water samples to exhibit its practical applications.
关键词： Cell imaging,Molecular keypad lock,Chemosensors,Turn-off Fluorescence,Mercury (II),Logic gates
更新于2025-09-19 17:15:36
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[SPIE Optical System Alignment, Tolerancing, and Verification XII - San Diego, United States (2018.8.19-2018.8.23)] Optical System Alignment, Tolerancing, and Verification XII - Introduction to optical alignment techniques: a long-running SPIE short course
摘要： The SPIE short course “Introduction to Optical Alignment Techniques” has been taught for over twenty years at many SPIE conferences. It has always been one of the well attended ones, indicating a need for the subject matter. Reviews of first order concepts, and the basic optical aberrations set the stage for understanding how optical systems become misaligned, how to recognize the aberration type and diagnose what is wrong. This will suggest solutions to the alignment problem, enabling failing optical assemblies to be corrected. The course closes with a discussion of the alignment issues that impact off-axis parabolas and higher-order aspheres.
关键词： off-axis aspheres,alignment telescopes,Optical alignment
更新于2025-09-19 17:15:36
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Performance improved tunable millimeter-wave signal generation employing UFBG based AOTF with bit walk-off effect compensation
摘要： A scheme for the generation of mm-wave signals at different frequencies with improved performance is proposed and demonstrated by employing a uniform fiber Bragg grating based acousto-optic tunable filter (UFBG-AOTF). The different frequencies carry different information at a required data rate according to their application. This method reduces the complexity of the system by alleviating the cascaded Mach-Zehnder modulators (MZM) and a good transmission performance can be achieved by the FBG. In the previous system, the distance of transmission is reduced to 15 km due to bit walk-off effect and it also reduces the BER values at larger distances. In the proposed system, the bit walk-off effect is discussed and compensated to increase the transmission distance up to 60 km. The simulation results along with clear eye-diagrams show that the BER values are improved at larger distances than the previous system which proves the performance improvement of the proposed system.
关键词： optical millimeter-wave,radio-over-fiber,bit walk-off effect,acousto-optic tunable filter,uniform fiber Bragg grating
更新于2025-09-19 17:15:36
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On-off-on fluorescent carbon dots from waste tea: Their properties, antioxidant and selective detection of CrO42?, Fe3+, ascorbic acid and L-cysteine in real samples
摘要： In this work, we reported an economical plant-based hydrothermal method for one-pot green synthesis of water-soluble carbon dots (Tea-CDs) by using waste tea extract as a carbon source. The synthesized Tea-CDs were characterized by UV-visible, fluorescence, FT-IR, TEM, XPS and XRD. The Tea-CDs were found to remove hydroxyl and superoxide anion radical in vitro. In addition, the Tea-CDs exhibited bright blue fluorescence under UV-light (λex=365 nm), and the fluorescence could be effectively quenched by CrO4 2- and Fe3+ ions. Meanwhile, the fluorescence of Tea-CDs-CrO4 2- and Tea-CDs-Fe3+ systems could be again easily recovered by ascorbic acid (AA) and L-cysteine (L-Cys). As an on-off-on fluorescent nano-sensor of the Tea-CDs, the sensitive detection of CrO4 2-, Fe3+, AA and L-Cys were all performed, showing that the good linear relationships between fluorescence intensity of Tea-CDs and concentration of all testing samples. Finally, the sensors successfully detected CrO4 2-, Fe3+, AA and L-Cys in commercially available real samples with satisfactory recovery ranges. The prepared sensors offer distinct advantages including low cost, simple handling, good sensitivity and high selectivity.
关键词： carbon dots,waste tea,L-cysteine,ascorbic acid,on-off-on fluorescent nano-sensor,metal ions
更新于2025-09-19 17:15:36