修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2018
研究主题
  • interdigital resonator
  • microwave gas sensor
  • PSE-coated
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • King Mongkut’s University of Technology North Bangkok
  • Rajamangala University of Technology Suvarnabhumi
571 条数据
?? 中文（中国） ▾

  • Printable Fabrication of a Fully Integrated and Self-Powered Sensor System on Plastic Substrates

    摘要： Wearable and portable devices with desirable flexibility, operational safety, and long cruising time, are in urgent demand for applications in wireless communications, multifunctional entertainments, personal healthcare monitoring, etc. Herein, a monolithically integrated self-powered smart sensor system with printed interconnects, printed gas sensor for ethanol and acetone detection, and printable supercapacitors and embedded solar cells as energy sources, is successfully demonstrated in a wearable wristband fashion by utilizing inkjet printing as a proof-of-concept. In such a “wearable wristband”, the harvested solar energy can either directly drive the sensor and power up a light-emitting diode as a warning signal, or can be stored in the supercapacitors in a standby mode, and the energy released from supercapacitors can compensate the intermittency of light illumination. To the best of our knowledge, the demonstration of such a self-powered sensor system integrated onto a single piece of flexible substrate in a printable and additive manner has not previously been reported. Particularly, the printable supercapacitors deliver an areal capacitance of 12.9 mF cm?2 and the printed SnO2 gas sensor shows remarkable detection sensitivity under room temperature. The printable strategies for device fabrication and system integration developed here show great potency for scalable and facile fabrication of a variety of wearable devices.

    关键词： wearable and flexible devices,printable supercapacitors,printable gas sensors,monolithically integrated self-powered systems,inkjet printing

    更新于2025-09-09 09:28:46

  • Dynamic simulation, control, and performance evaluation of a synergistic solar and natural gas hybrid power plant

    摘要： Solar power is considered among the leading renewable energy technologies. Abundant supply, flexibility of installation, and decreasing cost makes it an interesting renewable energy resource. However, there are challenges associated with the reliability of solar power due to its intermittent nature. This work demonstrates the synergies that exist in integrated hybrid systems, where a dispatchable fuel is used in conjunction with concentrated solar power. In this simulation-based study, a parabolic trough solar concentrator is used to collect solar energy. The heat collected from the solar field is used to generate steam in a Rankine cycle. The system also utilizes natural gas combustion in the steam generator to provide supplemental steam when the solar intensity is reduced due to cloud cover or at night. Natural gas is also used for superheating the steam, which allows the system to produce higher temperatures and achieve increased thermodynamic cycle efficiencies. This flexible design produces 100 MW at nominal conditions, while it is capable of producing a maximum of 140 MW when sufficient solar energy is available. The novel contributions of this work include a complete, systems-level, dynamic model of a hybrid solar plant. The model is complete with a control system that smoothly transitions the plant from pure natural gas mode at night to solar hybrid mode during the day. It evaluates innovative design features such as flexible fuel operation, steam superheating to boost efficiency, and preheating by solar or waste heat. Furthermore, this work demonstrates that by hybridizing a solar system with a dispatchable energy source, both the reliability and efficiency of the solar power production are increased. The annual solar-to-electric efficiency increases from 15.2% to 26.13% with hybridization, which indicates that utilization of the solar energy is effectively increased.

    关键词： Natural gas plant,Hybrid system,Dynamic simulation and control,Concentrated solar power

    更新于2025-09-09 09:28:46

  • Gas mixing effect on Kr ion currents from an ECR ion source

    摘要： Pure and different support gas-mixed krypton plasmas are produced using the 14.5 GHz all permanent-magnet based electron cyclotron resonance (ECR) ion source. The ions are extracted and the charge state distributions (CSDs) are studied. The H2, He, N2, O2, Ne, Ar, CH4 and CO2 gases are used as support gases. One of the support gases are mixed with Kr at several mixing ratios and its effect on the outputs currents of the Kr ions are studied. The total effective charge, as well as effective charges of Kr and mixing gas ions are calculated from the measured ion currents. The total ion loss rates are also calculated. The gases N2, O2, Ar and CO2 are found to exhibit better mixing effect in the enhancement of output of highly charged ions. The best enhancement in the output currents of Kr ions is observed in case of O2 as the mixing gas under certain conditions. To the best of our knowledge such a detail comparative study on the influence of mixing gas has not been reported so far for ECR ion-beam application.

    关键词： Krypton,Electron cyclotron resonance,Charge state distribution,Gas mixing

    更新于2025-09-09 09:28:46

  • Neck-Connected ZnO Films Derived from Core-shell Zeolitic Imidazolate Framework-8 (ZIF-8)@ZnO for Highly Sensitive Ethanol Gas Sensors

    摘要： Based on the neck-controlled conduction model of chemiresistive gas sensors, construction of neck-controlled conduction networks in metal oxide films is an efficient method to improve their sensitivity. In this work, we develop a facile route to prepare the neck-connected ZnO (NC-ZnO) films with controllable diameters of the necked part by the sintering of core-shell zeolitic imidazolate framework-8 (ZIF-8)@ZnO films. In order to certify the enhancement of sensitivity by construction of neck-controlled conduction networks, their gas sensing properties towards ethanol are systematically investigated. The results demonstrate that the sensitivity of the optimal NC-ZnO film is dramatically improved, and the response value is about 6-times higher than that of ZnO film, reaching up to 124 (Ig/Ia) towards 50 ppm of ethanol. The results meet our expectation and are in conformity with the neck-controlled conduction model, which further indicates the developed approach in this work is expected to open up a new strategy for the preparation of neck-connected metal oxide films.

    关键词： highly sensitive,ZnO,neck-controlled,ZIF-8,gas sensor

    更新于2025-09-09 09:28:46

  • Efficient Modified Bimetallic Alloy Nanoparticles Porous Silicon Gas Sensors for CO Gas Detection Process

    摘要： The influence of embedding Au, Pd monometallic and Au-Pd bimetallic nanoparticles on porous silicon-based gas sensor was investigated. Porous silicon layer P-si was prepared by photo electrochemical etching (PECE) with the laser wavelength of about 635 nm and 25 mW/cm2 laser power density. AuNPs/P-si, PdNPs/P-si and Au-PdNPs/P-si hetrostructures were prepared by ion reduction process, this made by dipping fresh P-si in the salt solution contain HAuCl4, PdCl2 and mixing solutions at ratio 1:1 for about (1.2, 5 and 2 min), respectively. Au NPs/P-si, Pd NPs/P-si and Au-Pd NPs/P-si were investigated by scanning electron microscopy (SEM), FTIR analysis, X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Efficient gas sensing process was recorded for modified porous silicon P-si gas sensor with smallest bimetallic Au-Pd nanoparticles size. Considerable improvement in sensitivity and temporal response were obtained for modified bimetallic alloy nanoparticles porous silicon compared with bare P-si and monometallic nanoparticles gas sensors due to the high specific surface area.

    关键词： Sensitivity,Ion reduction process,Monometallic,Photo Electrochemical Etching (PECE),Bimetallic,CO gas

    更新于2025-09-09 09:28:46

  • Ink-jet printing of a TiO2–10%ZrO2 thin film for oxygen detection using a solution of metal alkoxoacetylacetonates

    摘要： A solution of metal alkoxoacetylacetonates in isoamyl alcohol was used as a functional ink for ink-jet printing of TiO2-10%ZrO2 thin nanostructured films. It is shown that the anatase crystal lattice is formed during heat treatment of xerogel thin films in air at a temperature of 500 °C. According to the SEM scanning electron microscopy, the particle size of the resulting films was 10-11 nm. The effect of the number of TiO2-ZrO2 deposited layers on resulting 2D nanomaterial sensitivity to oxygen and other analyte gases (H2, CH4 and CO) at temperatures of 400 and 450 °C is shown.

    关键词： Gas sensor,Sol-gel,Titanium dioxide,Additive,Ink-jet printing,Alkoxoacetylacetonate

    更新于2025-09-09 09:28:46

  • Pd Nanoparticle Film on a Polymer Substrate for Transparent and Flexible Hydrogen Sensor

    摘要： Alongside the rise in fully automated equipment and the wearable devices, there is currently a high demand for optically transparent and flexible gas sensors operating at room temperature. Nanoparticle films are ideal H2-sensing materials that can be coupled with flexible substrates because of their discrete nanogranular structure and unique interparticle electrical responsiveness. In this work, we present an optically transparent and flexible H2 sensor based on a Pd nanoparticle film, prepared on a polyethylene terephthalate sheet using a straightforward nanocluster deposition technique. Hundreds of bending cycles demonstrated that the sensor has good electrical stability and mechanical robustness without significant degradation in H2-sensing performance. The H2-sensing behaviors under bent state were systematically evaluated. The loading of tensile and compressive strains under bent state produced a positive and negative influence, respectively, on the sensing performances. The possible influence mechanism of the tensile and compressive strains on H2-sensing performance was attributed to the changes in the percolation network topology and the interparticle space induced by the strains. The ability to detect an H2 concentration as low as 15 ppm, dynamic response range as wide as 0?10% and sub-10 s response time were achieved. In addition, the sensor can be operated in the relative humidity range of 0?90% at room temperature. These results demonstrate that the sensor exhibits significant potential for next-generation transparent and flexible H2 detector.

    关键词： flexible,palladium nanoparticle,transparent,hydrogen gas sensor,nanogranular

    更新于2025-09-09 09:28:46

  • Diffusion-Driven Al-Doping of ZnO Nanorods and Stretchable Gas Sensors Made of Doped ZnO Nanorods/Ag Nanowires Bilayers

    摘要： A crystal-damage-free nano-doping method, which utilized the vacuum drive-in diffusion of Al into ZnO nanorods, was developed. In this method, vertical ZnO nanorod arrays that were grown by chemical bath deposition beforehand were deposited with Al thin film and subsequently heat-treated under a high vacuum. At an optimum condition, the surface Al atoms were completely diffused into ZnO nanorods, resulting in Al-doped ZnO nanorods. Stretchable gas sensors were fabricated by sequentially drop-casting Al-doped ZnO nanorods and silver nanowires on PDMS substrate. The resistance and response of the sensor could be optimized through the elaborate control of relative densities of Al-doped ZnO nanorods and silver nanowires. The sensor showed a high response of 32.3% to 10 ppm of NO2 gas at room temperature, even under a large strain of 30%. The NO2-sensing mechanism of Al-doped ZnO nanorods/silver nanowires bilayer sensors is discussed on the basis of synergistic interplay of Al-doped ZnO nanorods and silver nanowires.

    关键词： Al-doped ZnO nanorods,Stretchable gas sensors,bilayers,drive-in diffusion,silver nanowires

    更新于2025-09-09 09:28:46

  • Investigations on gas-air mixture formation in the ignition chamber of two-stage combustion chamber using high-speed Schlieren imaging

    摘要： Combustion of the lean mixture in the spark ignition engines provides higher thermal efficiency compared to the combustion of the stoichiometric mixture but is more restrictive to the ignition systems. Due to the limitations of conventional ignition systems, advanced concepts are being used, e.g. spark-jet ignition. Presented research has been carried to determine: 1. The impact of fuel injection pressure on the velocity of mixture formation, 2. Fuel distribution inside the ignition chamber in defined phases of chamber filling, 3. Influence of chamber back-pressure on gas jet development. Investigations have been carried using the Schlieren-method with “Z”-setup basing on two ? = 150 mm parabolic mirrors. Images have been recorded with LaVision HSS5 camera with CMOS transducer. The paper contains a comparison of gas penetration parameters for a different injection pressures and chamber backpressures. The injection into the quasi-static air has been compared to the injection in dynamic conditions. It is stated, that both injection pressure and chamber back-pressure influence gas jet-development in the ignition chamber. The regions of the chamber with increased swirling and therefore providing more efficient micromixing have been identified.

    关键词： lean mixture,combustion,Schlieren method,spark-jet ignition,gas jet development

    更新于2025-09-09 09:28:46

  • Reduced Graphene Oxide–TiO2 Nanotube Composite: Comprehensive Study for Gas Sensing Applications

    摘要： Graphene oxide (GO) and reduced graphene oxide (RGO) have unique properties that can revolutionize performances of functional devices. Graphene-based materials can be coupled with metal oxide nanomaterials for gas sensing applications. In this work, we report the synthesis and the gas sensing properties of a composite material based on RGO loaded TiO2 nanotubes. To properly tune the reduction of GO to RGO we adopted a gas-phase process that can be applied in situ on each gas sensor device, allowing to track the process effects through the sensor conductance. We systematically investigated the gas-response dependence from RGO loading and its reduction, showing the occurrence of an optimal RGO concentration arising from the interplay of these two parameters. Hence, these two factors should be considered in parallel to functionalize the metal oxide materials with GO for the fabrication of chemical sensor devices.

    关键词： TiO2 nanotube,gas sensing,reduced graphene oxide,reduction effect,surface functionalization,Graphene oxide

    更新于2025-09-09 09:28:46