- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Liquefied petroleum gas sensing properties of ZnO/PPy/PbS QDs nanocomposite prepared by self-assembly combining with SILAR method
摘要： In this paper, a high-performance liquefied petroleum gas (LPG) sensor based on zinc oxide/polypyrrole/lead sulfide quantum dots (ZnO/PPy/PbS QDs) nanocomposite film was demonstrated, which was fabricated by layer-by-layer (LbL) self-assembly and successive ionic layer adsorption and reaction (SILAR) technique. The nanostructure features of the as-prepared ZnO/PPy/PbS nanocomposite film were confirmed by various characterization techniques. The room temperature gas-sensing investigation of the ZnO/PPy/PbS QDs nanocomposite sensor was performed against LPG gas in a wide concentration range. The experimental results showed an outstanding response for LPG sensing at room temperature compared with previous reports, the response can reach 45.47% at 1000 ppm LPG. And it also demonstrated good selectivity and excellent repeatability. The sensing mechanism of the PPy/ZnO/PbS QDs nanocomposite film gas sensor is owing to the p-n heterojunction created at the ZnO/PPy interface, as well as much more active adsorption sites.
关键词： polypyrrole,liquefied petroleum gas,zinc oxide,lead sulfide quantum dots,SILAR method
更新于2025-11-14 17:04:02
-
Sol–Gel Spin-Coating Followed by Solvothermal Synthesis of Nanorods-Based ZnO Thin Films: Microstructural, Optical, and Gas Sensing Properties
摘要： Zinc oxide thin films with nanorod morphology were investigated for microstructural and optical properties as well as their performance as a liquid petroleum gas sensing material. A two-step synthesis procedure consisting of sol–gel spin-coating and solvothermal methods was employed where several factors such as rational utilization of metal precursors, solvent, stabilizing, and structure directing agents, a repetitive drying-coating process, as well as post-thermal annealing were found influential to obtain qualified nanorods and a final homogeneous thin film. Compositional and optical investigations were pursued to characterize features, namely morphology, poly crystallinity, porous structure, nanocrystallite size, lattice oriented growth, textural atomic ratio, lattice purity and transparency, phonon and exciton transitions, as well as the formed structural defects via field-emission scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray, UV–Vis spectroscopy, Raman, and photoluminescence techniques. The as-prepared thin film was then used as an active LPG sensing material via a home-made gas sensor where the control sensing parameters were chamber testing temperature and gas concentration. Results showed a quantitative response of 92.7% as sensor sensitivity at an operation temperature of 250°C and a LPG concentration of 800 ppm in addition to fast response and recovery times of 44.1 s and 218.7 s, respectively.
关键词： Zinc oxide nanorods,thin film,optical characteristics,gas sensing,microstructural properties,liquid petroleum gas
更新于2025-09-23 15:23:52
-
Resistive room temperature LPG sensor based on a graphene/CdO nanocomposite
摘要： The authors decribe an ultra-sensitive, room temperature, flexible transparent LPG sensor based on the use of a CdO/graphene nanocomposite. The graphene prevents the accumulation of CdO, enhances the surface area, and acts as a gas sensing material. FESEM images show a uniform decoration of CdO nanoparticles on graphene. The CdO/graphene composite was deposited as a film on interdigitated electrodes (IDEs) which then were used for chemiresistive sensing of liquid petroleum gas (LPG) by using a four probe technique. A Resistivity decreases significantly upon exposure to a LPG. The electrical resistance measurement at a constant bias voltage of 0.5 V. The sensor of type CdO/graphene (1 wt.%) exhibits a sensitivity of 600 ppm of LPG at 27 °C. It is a highly selective, stable and sensitive to low concentration of LPG even at room temperature.
关键词： Gas sensor,CdO,Liquefied petroleum gas,Graphene,Flexible
更新于2025-09-23 15:23:52
-
Fluorescence spectroscopy of ancient sedimentary organic matter via confocal laser scanning microscopy (CLSM)
摘要： Fluorescence spectroscopy via confocal laser scanning microscopy (CLSM) was used to analyze ancient sedimentary organic matter, including Tasmanites microfossils in Devonian shale and Gloeocapsomorpha prisca (G. prisca) in Ordovician kukersite from North American basins. We examined fluorescence emission as a function of excitation laser wavelength, sample orientation, and with respect to location within individual organic entities and in transects across bedded organic matter. Results from spectral scans of the same field of view in Tasmanites with different laser lines showed progressive red-shift in emission maxima with longer excitation wavelengths. This result indicates steady-state Tasmanites fluorescence emission is an overlapping combination of emission from multiple fluorophore functions. Stokes shift decreased with increasing excitation wavelength, further suggesting the presence of multiple fluorophore functions with different S1 → S0 transition energies. This observation also indicates that at longer excitation wavelengths, less absorbed light energy is dissipated via collisional transfer than at shorter excitation wavelengths and may suggest fewer polar functions are preferentially absorbing. Confirming earlier results, emission spectra observed from high fluorescence intensity regions (fold apices) in individual Tasmanites are blue-shifted relative to emission from other locations in the same microfossil. We suggest high intensity emission is from photoselective alignment of polarized excitation with the fluorophore absorption and emission transition moment. The blue shift observed in regions of high intensity emission may be due to relative absence or realignment of polar species, e.g., bridging ether or ester functions, although variations in O abundance could not be confirmed with preliminary time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis. Tasmanites occurring in consolidated sediments are flattened from original spherical morphology and, in optical microscopy, this burial deformation results in generally parallel extinction (strain-influenced) and positive elongation. The deformation also induces fluorescence anisotropy observed as variations in emission wavelength when individual Tasmanites are measured from their long axis parallel to bedding, whereas this effect is absent in bedding-normal view. Transects from G. prisca-rich source layers into adjacent reservoir layers show decrease in fluorescence intensity and spectral red-shift (increase in full-width half-maximum with increasing red portion of the half-width). These results may suggest an increase in fluorescence quenching across the source-to-reservoir transition zone, consistent with an increase in aromaticity following petroleum expulsion and migration. These observations are supported by increasing reflectance values measured across similar micro-scale transects. Our results highlight the applicability of CLSM as a broad and under-utilized approach for the characterization of sedimentary organic matter and are discussed with perspective toward petroleum processes and thermal indices research.
关键词： Gloeocapsomorpha prisca,Confocal laser scanning microscopy,Tasmanites,Petroleum processes,Fluorescence spectroscopy,Sedimentary organic matter,Thermal indices
更新于2025-09-23 15:21:01
-
Artificial Intelligence Assisted Mid-Infrared Laser Spectroscopy In Situ Detection of Petroleum in Soils
摘要： A simple, remote-sensed method of detection of traces of petroleum in soil combining artificial intelligence (AI) with mid-infrared (MIR) laser spectroscopy is presented. A portable MIR quantum cascade laser (QCL) was used as an excitation source, making the technique amenable to field applications. The MIR spectral region is more informative and useful than the near IR region for the detection of pollutants in soil. Remote sensing, coupled with a support vector machine (SVM) algorithm, was used to accurately identify the presence/absence of traces of petroleum in soil mixtures. Chemometrics tools such as principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA), and SVM demonstrated the effectiveness of rapidly differentiating between different soil types and detecting the presence of petroleum traces in different soil matrices such as sea sand, red soil, and brown soil. Comparisons between results of PLS-DA and SVM were based on sensitivity, selectivity, and areas under receiver-operator curves (ROC). An innovative statistical analysis method of calculating limits of detection (LOD) and limits of decision (LD) from fits of the probability of detection was developed. Results for QCL/PLS-DA models achieved LOD and LD of 0.2% and 0.01% for petroleum/soil, respectively. The superior performance of QCL/SVM models improved these values to 0.04% and 0.003%, respectively, providing better identification probability of soils contaminated with petroleum.
关键词： chemometrics,soil,artificial intelligence (AI),multivariate analysis,mid-infrared (MIR) laser spectroscopy,petroleum,quantum cascade lasers (QCLs)
更新于2025-09-23 15:19:57
-
Plasmon‐Enhanced InGaZnO Ultraviolet Photodetectors Tuned by Ferroelectric HfZrO
摘要： Allene (C3H4) gas is produced and separated on million-metric-ton scale per year during petroleum refining but is rarely employed in organic synthesis. Meanwhile, the addition of an allyl group (C3H5) to ketones is among the most common and prototypical reactions in synthetic chemistry. Herein, we report that the combination of allene gas with inexpensive and environmentally benign hydrosilanes, such as PMHS, can serve as a replacement for stoichiometric quantities of allylmetal reagents, which are required in most enantioselective ketone allylation reactions. This process is catalyzed by copper salts and commercially available ligands, operates without specialized equipment or pressurization, and tolerates a broad range of functional groups. Furthermore, the exceptional chemoselectivity of this catalyst system enables industrially relevant C3 hydrocarbon mixtures of allene with methylacetylene and propylene to be applied directly.
关键词： enantioselective allylation,allene,copper catalysis,hydrosilanes,petroleum cracking byproduct,ketones
更新于2025-09-19 17:13:59
-
Comparative laser-induced fluorescence evolution analysis of different oil pollution on the terrestrial surface
摘要： We have studied the time evolution of the laser-induced fluorescence spectra of oil pollution on the terrestrial surface at a fluorescence excitation wavelength of 355 nm. The paper presents a block-diagram of the experimental laboratory setup and data processing results of the laser-induced fluorescence spectra for the oil-polluted soil and sand and conducts a comparative analysis of the fluorescence spectra evolution of pollution due to spilling crude oil and heavy and light petroleum products.
关键词： petroleum products,laser-induced fluorescence,terrestrial surface,oil pollution
更新于2025-09-12 10:27:22
-
[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - 10.3% Efficient CuIn(S,Se)<inf>2</inf> Solar Cells from DMF Molecular Solution with the Absorber Selenized under High Argon Pressure
摘要： Owing to the transformation of the biomedical model of health, more and more professionals pay close attention to the occupational social psychological factors, such as occupational stress. Due to the socioeconomic impact of occupational stress and the petroleum workers stationed in the unique environment in Xinjiang, a cross-sectional study was carried out between May and December 2016 to investigate the relationship between occupational stress and demographic characteristics. A total of 1480 workers were selected. Occupational stress was evaluated with the Occupational Stress Inventory-Revised Edition. The findings of the present study revealed that the values of the Occupational Roles Questionnaire results (t = 9.266, P < .001) and Personal Strain Questionnaire results (t = 21.381, P < .001) were found to be higher than the national normal. Personal Resources Questionnaire values (t = (cid:1)17.575, P < .001) were found to be lower than the national normal in petroleum workers stationed in the arid desert, and suggested a strong correlation between occupational stress and demographic characteristics. These data provide evidence that different demographic characteristics are associated with different occupational stress levels in petroleum workers stationed in the arid desert.
关键词： occupational stress,petroleum workers,arid desert,demographic characteristics
更新于2025-09-11 14:15:04
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Automatic Recognition of Oil Industry Facilities Based on Deep Learning
摘要： Effectively monitoring the real-time position and status of oil facilities (mainly well-site) in oil field is very important for the safety production. Considering the low efficiency of traditional visual interpretation method and the high demands of preset feature for machine learning method, one of the object detection methods in Deep learning (YOLOv2) was introduced to recognize oil industry facilities automatically. After establishing the dataset of oil facility samples, 90 percent of samples are used for model training while 10 percent are for validating. Comparing with the results extracted by machine learning (Adaboost model based on Haar-like), YOLOv2 recognition results of oil facilities indicated that: Deep learning improve the recognition efficiency and accuracy of oil facilities. The accuracy can be as high as 92% while the error rate and omission rate can be maintained in a low level. At the same time, the constructed model was applied in an oilfield in eastern part of China, and the result shows that the model can identify most of the oilfield facilities correctly with only 4% omission rate, which is much lower comparing with manual interpretation. However, the 11% error rate, caused by insufficient sample types and sample quantities, is relatively high especially in city area.
关键词： machine learning,petroleum industry facility,deep learning
更新于2025-09-10 09:29:36
-
[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Low-THz Transmission Through Liquid Contaminants on Antenna Radome
摘要： The effect of a uniform layer of petroleum-based fuels, gasoline and diesel, on wave propagation through a radome at 150 GHz and 300 GHz is studied theoretically and empirically. The measured results are compared with a theoretical calculation and are found to be in good agreement. Transmissivity higher than -2 dB and -5 dB is measured through a 15 mm layer of diesel at 150 GHz and 300 GHz, respectively. Transmissivity through a 15 mm uniform layer of gasoline is recorded to be about -15 dB for both frequencies. However, the antenna radome for outdoor automotive applications is more likely to be covered by diesel than gasoline, due to the weaker dispersion and faster evaporation of gasoline.
关键词： radomes,transmissivity,petroleum-based fuels,low-THz waves
更新于2025-09-04 15:30:14